The role of the medial lemniscal and spinocervicothalamic pathways on tactile reactions in cats. The role of dorsal column (DC)-medial lemniscus and spinocervicothalamic systems on tactile reactions, placing and tactile localization (turning to localize a point touched on the body) was studied in cats with spinal and bulbar lesions. The cats with vision occluded were trained preoperately on horizontal bars for tactile localization. The bulbar lesions of cervicothalamic tract (CTT), which anatomically overlaps with gracile nuclear efferent projection, resulted in permanent loss of tactile placing and localization in contralateral hindlimb. Section of dorsal half of lateral funiculus at C3, which interrupts afferents to lateral cervical nucleus but also involves descending motor pathways, gave loss of tactile placing without impairment of tactile localization. However, combined lesions of both systems abolished tactile placing and localization permanently. Results suggest that tactile placing and localization persists after CTT lesion alone; temporarily loss after DC section but permanently abolished after destruction of both systems. It. is also noted that cats after lesions of both systems without involving motor pathways could walk on bars without vision. The deficits following combined lesions are suggested to be primarily sensory in nature.


Compensation of edge effect in neuron-like layer nets with local feedbacks. One or two-dimensional layer nets with local feedback between neuron-like elements were investigated. The mutual influence between elements of the net is based on the principle of lateral inhibition. A properly adapted and modified Z-transform method applied to a difference equation describing the function of the net allowed us to characterize the properties and dynamics of the net and to define its stability region. Finite dimensions of the net cause "reflections" of signals from the edges of the structure. This makes the detection of pattern difficult or even impossible and therefore the problem of compensation of the edge-effects appears. Several methods of compensation, involving discrete or continuous change of coupling weights, are described. A comparison of the behavior of a compensated and uncompensated net, as modelled on a digital computer, shows the advantages of the compensation.


Body composition in control, alcoholic and depressive individuals using a multiple isotope technique and whole body counting of potassium. (1) Height, weight, total body potassium, exchangeable sodium, bromide space, total body water and concentrations of sodium, potassium and chloride in plasma were measured in control subjects and individuals suffering from alcoholism, with techniques which included body counting and a multiple isotope method using 24Na, 82Br and 3H2O. (2) No differences were found between control and alcoholic subjects so there was no evidence that chronic alcoholism altered body composition. In particular there was no eficence of cellular damage or loss which would have been reflected in changes in KT or KIN. (3) The data were combined and were analysed to give information on the relationships of the variates. (4) On-going work by the author on tryptophan metabolism in primary alcoholics is compared to Shaw's findings on the kinetic behaviour of tryptophan in affective disorder. The possible prophylactic value of L-tryptophan (Optimax) in preventing both recurrent depression and recurrent alcohol abuse is outlined. (5) Data on body composition in normal subjects not hitherto available in the literature is provided.


Does histamine have two vasodilator actions on the gastric mucosa? It has been shown previously that there is a greater gastric mucosal blood flow response to histamine than to gastrin stimulation for similar acid secretory values. We have confirmed these observations under steady state conditions and also shown that the oxygen consumption depends on acid secretion in a similar way for both histamine and gastrin stimulation. Furthermore the degree of oxygen extraction from the gastric circulation is significantly less (p less than 0.001) during histamine stimulation than during gastrin stimulation. This supports the hypothesis that histamine causes a vasodilatation in the gastric mucosa in two ways, one may be linked to secretory activity and the other a pure dilator action.


Phosphopyridoxal complexes with histamine and histidine. (1) The kinetics of complex formation between pyridoxal 5'-phosphate and histamine. Amines and amino acids are able to form cyclic compounds with pyridoxal 5'-phosphate (PLP). The quantitative relationship between histamine and PLP in the cyclization reaction were examined. It was found that one mole of amine reacts with one mole of coenzyme. The velocity of complex formation increased with an excess of either histamine or PLP, without any change in molar ratios. The formation of cyclic compound was confirmed by the use of isotopic method. The separation of cyclic compound from histamine, but not from PLP, was achieved by paper chromatography.


Are platelets important in inflammation? The participation of platelets in acute inflammation was tested by three different traumas in rats rendered thrombocytopenic with anti-platelet serum. Thrombocytopenic rats showed normal oedema response to carrageenin, anti-platelet serum and passive cutaneous anaphylaxis.


Histamine content and synthesis in central and pheripheral nerve structures during stress. Histamine content and histidine decarboxylase activity in cortex and hypothalamus, together with histamine content in peripheral nervous structures were examined in normal and electrically stressed guinea-pigs. A significant increase in histidine decarboxylase activity in hypothalamus and cortex together with concomitant decrease in histamine content in hypothalamus have been found. Electric shock causes also a decrease in histamine content in spinal cord, spinal ganglia, dorsal roots and sensory nerve. The function of histamine in nervous system is discussed.


Effect of single and multiple treatments with phenylbutazone in normal and adjuvant-induced polyarthritic rats. Liver function alterations, in the adjuvant induced polyarthritis procedure in rats, has been demonstrated by many investigators. We observed a significant inhibition of the polyarthritis with phenylbutazone but we were unable to find any changes in the relative liver weights of SGPT, AP or BUN in polyarthritic or phenylbutazone treated rats. However, we did observe that polyarthritic rats maintained a significantly higher plasma phenylbutazone concentration than the corresponding non-arthritic controls. This appears to futher substantiate the influence of 'pathopharmacodynamics' on the disposition and activity of drugs.


Effect of antiphologistics on blood-brain barrier in lymphostatic encephalopathic and in normal rats. Injection of the tremorigenic alkaloid harmine into lymphostatic encephalopathic rats leads to a longer duration of tremor and higher brain concentrations than in sham-operated controls. In lymphostatic encephalopathic as well as in normal rats different antiphlogistics shorten the tremor duration and decrease harmine concentration in brain. The antiphlogistics do not influence the plasma concentration of harmine, its protein binding and its tremorend concentration in brain. The effect of antiphlogistics in lymphostatic encephalopathic rats is considered as a consequence of the reduced blood-brain barrier permeability. Obviously in sick animals the blood-brain barrier permeability for harmine is not increased; the prolonged harmine tremor and the increased alkaloid concentration in the brain are consequences of the impaired cerebral lymphatic drainage only.


Effect of zexbrevins A and B. Two new sesquiterpene lactones, on the immune response of mice. Two newly described sesquiterpene lactones, Zexbrevin A and Zexbrevin B, were administered to mice at microgram doses before a single immunizing dose of sheep red blood cells (SRBC), bovine serum albumine (BSA), or Egg albumin (Ea). It was found out that drug treated and immunized animals displayed high numbers of specific spleen rosette forming cells (RFC), as well as elevated titers of circulating antibodies, as compared with mice stimulated solely with antigens. 500 mug of Zexbrevin A and Zexbrevin B was about the best dose for rosette increase; 700 mug or lesser amounts of both drugs induced a decline in the rosette numbers. It was evident that Zexbrevins had to be administered 48 hours before antigen stimulation; no potentiation was obtained if the drugs were given 3 to 11 days before the antigen. No effect was obtained, as well, when mice were treated with drug and antigen on the same day. In the presence of Zexbrevins the radioactive thymidine uptake of cultured normal mouse spleen cells will not increase above controls, indicating that mitogenic effects appear not to be involved in the potentiation. It is concluded that the sesquiterpene lactones exert in mice a potent stimulation of the in vivo response.


Allergic pathogenesis in chronic bronchitis. Chronic bronchitis is a disease related to numerous etiologic factors: infections, climate influence, air pollution, cigarette smoking, etc. From a pathogenetic point of view, chronic bronchitis is generally considered as the phlogistic resultant of various irritative conditions, with a characteristic neutrophil component in the phlogistic pattern. Microbic involvement has up to now been considered a very important factor, with consequent wide utilization of antibiotic agents in basic therapy. Considerations of clinical nature induced us to consider unsatisfactory such pathogenetic concepts based on neutrophil phlogosis, while the involvement of an allergic mechanism became more acceptable. In order to solve this problem, we have carried out hitological studies on postmortem material from the respiratory tract of individuals whose death was attributable to chronic bronchitis or to concurrent chronic bronchitis. Results of our study conducted up to now on 60 cases may be summarized as follows: Bronchitis with lymphomonoplasmacytoid phlogosis of immunoallergic type (60%), bronchitis with neutrophil phlogosis of irritative-infective type (20%); bronchitis with mixed allergic-neutrophil phlogosis (20%). Lymphocytes, monocytes and plasma cells are directly involved in allergic tissue reactions, both of immediate and delayed type because they release active substances such as hsitamine, bradyquinine, quinine, etc., which will their multiple pharmacodynamic actions are responsible of various anatomic and functional changes in hypersensitivity. Infiltration of the bronchial mucosa with lymphomonoplasmacytary cells in chronic bronchitis, has a pattern of mixed allergic phlogosis of immediate and delayed type. Prophylaxis and management of chronic bronchitis should therefore be set up on new bases, with the various treatments used for hyperactive pathology.


Subclinical psychomotor and neuromuscular changes in workers exposed to inorganic mercury. Workers exposed to metallic mercury vapor were subjects for EMG, hand tremor and psychomotor tests conducted over an eighteen month period. Performance decrements in neuromuscular functions and psychmotor skills were found to be reversible and correlated  with blood and urine mercury levels.


The criterion of the inhalation test to allergens at establishing specific hyposensitizing in allergic asthma. The experience we had in our casuistics as regards 1,000 asthmatics, demonstrates the positive inhalation test (IT) to allergens, only in about 40% of the asthmatics having positive cutaneous test (CT). The technic for determination has used the FEV1 criterion. We correlated the data of the anamnesis (A), CT and IT. The indications of allergenic etiology concerning A, have been divided into three categories: certain anamnesis (CA), suggestive anamnesis (SA) and unconclusive anamnesis (UA). At asthmatics having + CT, CA was associated to + IT in 92%, to SA in 49% and to UA in 11% of the cases. At asthmatics having --CT, CA is possibly associated to + IT, much more rarely associated to SA and not at all associated to UA. From these correlations we deduce the value of A and the fact that --IT is sometimes a false negative test. It further results that IT is not absolutely necessary in cases having CA and + CT. However, IT becomes useful in cases having CA/SA and --CT, as well as in cases having SA/UA and +CT. In 611 persons having allergic asthma lasting cures (1-6 years) of SH have been obtained successfuly in 92% and unsuccessfuly in 8% of the cases. From this total, lot 1 (437 cases) has been selected according to criterion CA/SA and +CT; lot II (130 cases) has associated in addition to criterion of selection by +IT; lot III (44 Cases) was selected with CA/SA, +CT and --IT. Although the selection has been different, the SH results have been identical. From this we infer the spheres of SH efficacy exceed the limit of every selection criterion mentioned before. Further it is to be inferred that the routine IT brings a satisfactory selection for the SH decision only in the mentioned conditions.


Abrasive blasting protective practices study--field survey results. A nationwide field survey of abrasive blasting practices revealed equipment deficiencies and lack of maintenance to be the rule, with workers exposed to extreme noise environments and above TLV quartz exposures.


[Etiopathogenesis of atopic dermatitis]. There is a wide variety of criteria in regard to the etiology of atopic dermatitis of neurodermitis. The allergic factor may play a very important role in its etiology. There is neither a general agreement on the importance of food allergy in this regard. Broadly considered, these patients may evoke intense positive reactions to intradermal tests to food and inhalative allergens, nevertheless it will be possible to establish that the lesions appear or disappear after the exposure of suppression of the antigens which evoked the positive reaction. On this basis, many dermatologists deny the allergic etiology in atopic dermatitis, even though in most instances no food skin tests are performed. In this study, 110 patients, both children and adults of both sexes, suffering from atopic dermatitis are investigated. The onset in most of the cases is before the age of six months, following the ages between 1-10 years; the groups between 6 months and one year, and 10-20 years followed a descending order per decade until 70 years. 60.9% of the cases showed food allergy to one or more food items. In 39% of the cases, no food allergy was found. The food-stuffs more commonly involved were: milk (37.7%), egg (26.3%) and fish (20.9%), followed by coca, wheat flour, seafood, fruits, vegetables and meat. A remission of the reaction followed the suppression of the allergen. Intestinal parasitosis is evaluated in relation to atopic dermatitis. 30.9% of the 110 cases were affected with intestinal parasitosis, being the most common the flagelates (lamblias), protozoa (amoeba) and nematodes (ascaris, tricocephalus and oxijrus). Finally, a concurrence is found between atopic dermatitis and other allergic diseases in 81 cases (73.6%), being bronchial asthma and asthmatic bronchitis the most frequent, and allergic rhinitis, urticaria and Quincke's edema less frequent.


A successful respirator program.

A successful respirator program. This discussion covers the successful implementation of a respirator program on a voluntary basis in a large industrial plant. The program had the stated objective of mandatory usage at the end of a specified period of time. It was successfully implemented in an 1100-man department. This practical approach is applicable to large and small plants.


Diagnostic value of total IgE and antigen specific IgE using RAST in pollenosis. 41 patients with clinically demonstrated pollinosis are studied. The following test were performed on all of them: a) Intradermal skin tests using grass pollen extracts (Pangramin III) and with extracts of Dactylis glomerate, Lollium perenne and Poa pratensis. b) Totol serum IgE determination. c) Antigen specific IgE (RAST) determination against the pollens mentioned in b). d) Passive hemagglutination against the pollen Dactylis glomerate. Basing on the results obtained, we have arrived to the following conclusions: 1) IgE determination with intensely positive intradermal skin tests in all cases, gave the following data: 27.5% normal values, 35% slightly elevated and 37.5% highly increased values. We believe that IgE determination can only be used to estimate the "allergization" degree of the patient. 2) No relation between the antigen concentration used in the intradermal skin test, and serum IgE concentration was found. 3) Taking in consideration that the antigen extracts used for RAST and intradermal skin tests were obtained from different sources (Sweden and Spain, respectively), the relation between both determinations ranged between 52.5% and 60%, in a total of 123 tests performed. 4) Considering that in the allergic response antibodies other than reagins (IgG) take part, and taking into account the results obtained with the passive hemagglutination technique, we consider that this last method should be included as a diagnostic routine tool in the pollinic patient.


Development of gas-blending systems for calibration: application to hydrogen fluoride, arsine and phosgene in air. Preparation of samples of known concentration of hydrogen fluoride, arsine and phosgene in air from 0.5 to 10 times the TLV is described. These are required to evaluate and calibrate analytical monitoring devices used for measuring these gases in work atmospheres. Dynamic gas-blending systems have been constructed and evaluated at the National Bureau  of Standards for preparing these samples. Measurements to estimate the long term concentration stability of these gases are also included.


Linking industrial hygiene and health records. This report presents methodology used in a large chemical company for linking historical industrial hygiene sampling data and employee health data through the personnel record system. The problems encountered are described to alert investigators to the need for careful planning of systems for linking the three data bases.


The association of vinyl chloride exposures with morbidity symptoms. A mail-out questionnaire examined symptoms previously associated with vinyl chloride exposure. Assessment of exposure levels was made by analytical measurement and observation. The resulting statistical analysis revealed a dose-response type of relationship between exposure and certain morbidity symptoms.


Thermal responses to intermittent work in selected enironments. Acclaimed subjects exercised intermittently for 8 hrs in 25 to 50 degrees environments. Thermal and metalobic determinations were made. Results showed the time-weighted WBGT heat strain index for intermittent work needs re-evaluation. For acclimated subjects working steadily at 350 kcal/hr, 30% max, the ULPZ is more than 33% WBGT.


The effects of broadband noise on the cardiovascular system on normal resting adults. Blood pressure, pulse rate and pulse pressure were determined at 2-minute intervals on 20 healthy subjects while they were exposed to 91-dBA continuous broadband noise for 1 hour. Control data were obtained by replication without the noise. The noise produced no statistically significant changes in any of the cardiovascular parameters under study.


Monitoring personnel exposure to vinyl chloride, vinylidene chloride and methyl chloride in an industrial work environment. Pittsburgh PCB 12 times 30 activated carbon is found to be the most suitable of the commerically available carbons tested for personnel sampling of vinyl chloride, vinylidene chloride, and methyl chloride. The carbon is desorbed with CS2 at dry ice temperature or with a thermal desorption technique.


Interpreting noise dosimeter results based on different noise standards. Three types of noise dosimeters were exposed on workers during routine work in a synthetic rubber plant, two refineries, a petrochemical plant, a petroleum marketing terminal and an off-shore producing platform. The dosimeters represent different methods of noise integration.


Performance of the slotted impactor.

Performance of the slotted impactor. Slotted impactors perform with a sharpness of cut close to the theoretically predicted value, if used under the conditions of the numerical model. Sideways flow entrance and impaction onto a fibrous surface may change the collection efficiency considerably.


The  design and calibration of a low speed windtunnel for studying the foliar deposition and uptake of aerosols. A 2.75 m-long (9 ft.) windtunnel facility to deliver highly toxic aerosols to the foliage of terrestrical plants under safe and well-characterized conditions is described. Flow velocities of 0.1 to 28 cm/sec in the 930 cm2 (1 ft2) cross-section experimental area are attainable. Calibration of this facility using a 198Au-labelled colloidal gold aerosol is presented.


Fine structure of hepatocytes from fasted and fed rats. The fine structure of hepatocytes from rats maintained on a controlled feeding schedule are described. Liver samples were processed for electron microscopy, histochemistry and chemical determinations of glycogen at precise time-intervals following a 30-hour fast and a 2-hour meal. Hepatocytes from 30-hour-fasted rats with extremely low hepatic glycogen levels were devoid of glycogen particles. Centrilobular cells showed areas of the cytoplasm rich in vesicles of smooth endoplasmic reticulum (SER) while periportal hepatocytes contained less extensive regions of SER. Soon after feeding the fasted rats, glycogen particles appeared in regions of the cell rich in SER. Centrilobular hepatocytes contained numerous glycogen areas which were infiltrated with tubules of SER, while periportal cells showed dense glycogen deposits with SER restricted to the periphery of the masses of glycogen. Throughout glycogen deposition each glycogen particle was closely associated with membranes of SER until maximum glycogen deposition was achieved 12 hours after initiation of feeding. At this point SER was reduced to the lowest amounts of the time-periods studied. During stages of glycogen depletion SER proliferated and reached the highest concentration measured in this study. Tubules of SER were present throughout the glycogen masses of centrilobular hepatocytes, whereas in periportal cells the organelle was restricted to the periphery of the glycogen masses. It is concluded that SER is associated with glycogen particles in rat hepatocytes during both deposition and depletion of glycogen.


A light and electron microscopic study of the pineal gland of the ground squirrel, Citellus tridecemlineatus. The pineal gland of the 13-lined ground squirrel (Citellus tridecemlineatus) has been examined at the light and electron microscopic level. This gland is composed of low-density parenchymal cells interspersed among which are occasional glial, vascular and neural elements. Punctuating the glandular parenchymal mass are prominent perivascular and intercellular spaces. The parenchymal cells possess numerous mitochondria and less prominent profiles of rough and smooth-surfaced endoplasmic reticulum. Golgi apparatus, microtubules and lipid droplets of varying size and electron density constitute regular cytoplasmic features, with dense-core vesicles being present occasionally. The parenchymal cells have numberous processes. One among these in each cell extends for several micra to terminate in a bulbous expansion containing both clear and dense-core vesicles and occasional electron-dense inclusions. These bulbous terminals are found within the perivascular and intercellular spaces where they course in close proximity to both other parenchymal elements and axon terminals. Glial cells and their processes invest the pineal periphery and incompletely separate the parenchymal cells.


Neuroanatomical clues to peripheral locomotor control in small crustaceans (Artemia salina). Brine shrimp (Artemia salina) were prepared for light and electron microscopy at several stages. Immersion-fixed, rapid Golgi impregnations demonstrated two distinct neuronal types in thoracic appendages of mature, freely swimming Artemia. Isolated motor neurons had large cell somas and thick, radiating dendrites at the body wall-limb junction. A long, elaborate axon extended into the limb. Groups of a second type of neuron with smaller somas and very thin, radiating processes occurred in the distal limb near presumably tactile bristles. Thick axons from motor neurons were traced to terminals associated with limb muscle. Both muscle and axon were best seen with Nomarski optics. Motor axons possessed elongate, irregularly shaped boutons en passant and morphologically variable boutons terminaux; the latter included huge endings with knobbed projectiles arising from thick collaterals, or smaller, round boutons from thin collaterals. In addition, a thick unidentified axon coursed longitudinally within the central body wall, sending short collaterals peripherally. The elaborate peripheral neurons described in this Golgi study may be anatomical correlates for the extraordinary coordination of mature brine shrimp. Because Artemia movements resemble those of leech and decapods, which have been studied extensively electrophysiologically, the possibility of similarly elaborate peripheral structures supplementing central control of locomotion in those invertebrates should be considered.


Carbohydrate histochemistry of the opossum submandibular and major sublingual glands. Submandibular and major sublingual salivary glands of the opossum contain histochemically demonstrable neutral mucosubstances, nonsulfated acid musosubstances and sulfomucins. Sialomucins could not be demonstrated conclusively with the methods used in this study. Special serous cells of the opossum submandibular gland contained low concentrations of acidic mucosubstances but no appreciable concentration of neutral mucosubstances was seen. Sulfomucins were not observed in special serous cells. The mucous tubules of the submandibular gland contained high concentrations of neutral mucosubstances. No appreciable acidic mucosubstance was demonstrated in the submandibular gland mucous tubules. Unlike the mucous tubules of the submandibular gland, the major sublingual gland mucous tubules contained high concentrations of both neutral and acidic mucosubstances. The mucous tubules often contained sulfomucin-positive cells interspersed among cells that contained high concentrations of non-sulfated acidic mucosubstance. Marked staining of sulfated acidic mucosubstance was seen only in the major sublingual gland, in both the mucous tubules and in the seromucous demilunes. The seromucous demilunes contained both sulfated and non-sulfated acidic mucosubstances.


A morphological and histochemical study of the developing tongue musculature in the mouse: its relationship to palatal closure. Some question exists concerning the ability of the embryonic tongue to undergo reflex movements at the time of palatal closure (15.5 days of development). Functional motor endplates are prerequisite for such movements to occur. Light and ultrastructural cytochemical methods were employed to elucidate the morphology of neuromuscular relationships in the developing mouse tongue. The A/Jax mice used in the experiments demonstrated a 12-20% incidence (seasonal variation) of spontaneous cleft palate, allowing a correlation between normal and teratological processes. Organized myofibrils were first seen in tongues of normal and spontaneous cleft lip-cleft palate (SCL-CP) specimens at 14.5 days of development. The thiocholine technique of Karnovsky and Roots was used to demonstrate acetylcholinesterase (AChE) activity at the light microscope level. The Lewis and Schute method was used for ultrastructural localization of this enzyme. Tissues from normal and SCL-CP specimens from 12.5 to 20.5 days of gestation failed to show differences in amounts or distribution of AChE activity. AChE activity was seen as early as 14 day's gestation. Electron microscopic studies demonstrated reaction product in the endoplasmic reticulum and nuclear envelope of developing myoblasts. AChE activity at the developing neuromuscular junction and the occurrence of myofilaments preceded palatal closure by several days. Based on these morphological and histochemical findings the tongue of normal and SCL-CP embryos appears capable of responding to a neurogenic stimulus at the time of palatal closure. The findings suggest that the tongue of animals exhibiting a spontaneous cleft palate is not actively involved in the etiology of this condition.


Estrogen and antagonist-induced structural changes in the cervico-vaginal epithelium of immature rats. Estrogen enhances proliferation and keratin formation in the cervico-vaginal epithelium of immature rats, whereas the estrogen antagonist, CI-628 (Parke-Davis), represses mitosis and induces mucinogenesis. Combinations of antagonist and estrogen allow differentiation of an epithelium composed of both keratin-forming and mucous cells. Both estrogen and antagonist induce synthesis of a cervico-vaginal endogenous peroxidase in the intermediate and superficial layers of the epithelium. The secreted vaginal mucus of antagonist-treated animals stains intensely for exogenous peroxidase.


Macrophage-lymphocyte clusters in lymph nodes: a possible substrate for cellular interactions in the immune response. The lumens of the lymphatic sinuses in lymph nodes are traversed by fibrocellular trabeculae. Joined to these trabeculae were macrophages, which formed cell clusters with lymphocytes. It is proposed, based on structural similarities, that these cell clusters are the equivalent in vivo to those seen during primary and secondary immune responses in vitro. These intraluminal macrophages were located in the path of lymph-borne antigen, as well as in the path of newly formed and recirculating lymphocytes in sinuses. This would facilitate the possible interaction between macrophage-associated antigen and antigen-reactive lymphoid cells. The attachment of numerous lymphocytes to the surfaces of macrophages and the resulting cell clusters also afford increased opportunities for lymphocyte-lymphocyte contact.


Capillary innervation in the mammalian central nervous system: an electron microscopic demonstration. Capillaries in the cat hypothalamus receive axon terminals which are comparable to neurovascular junctions in cerebral and systemic arteries and arterioles. The innervation of capillaries in the central nervous system may be derived from central neurons, in contrast to cerebral arterial vessels, which are supplied by the peripheral autonomic nervous system.


Mitochondrial granules of chondrocytes in cryosections of growth cartilage. Fresh frozen specimens of growth cartilage have been dry-sectioned and examined in the electron microscope without any staining. Dense granules in the mitochondria of chondrocytes were observed near calcifying areas. This confirms the presence of these mineral granules in the original tissue because this technique avoids the preparative artefacts of conventional electron microscopy.


Mitotic cells and their microappendages in the primitive streak of the chick embryo. Fresh pullet eggs (White Leghorn Strain) were incubated to the primitive streak stage of development. Blastoderms were fixed in situ with isotonic aldehyde fixatives and prepared for scanning electron miscropy by means of post-osmication, critical point drying and gold-palladium coating. Cells judged to be in various stages of mitosis by their surface contours were numerous on the ventral surface of the chick blastoderm. Cells which were in the late preparatory stages for mitosis had rounded up from their surroundings. Microvilli dominated the surface. The degree of separation and number of microvilli increased until late metaphase or anaphase. Mitotic cells did not completely separate themselves from adjacent cells. Ruffles and blebs were not prominent during mitotis and long filopodia were absent. A definite localization of microappendages (microvilli, blebs, ruffles) to the area of cytokinesis was evident in early telophase and persisted through daughter cell formation.


Folic acid and vitamin B12 determination in fetal liver. The folate and vitamin B12 content of 61 fetal livers divided into 3 groups immature (13 cases); premature (27 cases); at terminus (21 cases) were determined microbiologically. The average concentration (mug/g) and the reserve (mug) of hepatic folate for the immature group were 2 and 43.2 (net weight); for the premature group were 3.05 and 163.6; for the third group were 2.54 and 225.3, respectively. The average concentration (mug/g) and the reserve (mug) of hepatic vitamin B12 for the immature group were 0.173 and 4.1; for the premature group were 0.207 and 10.7; for the third group were 0.300 and 27.3 respectively.


Effects of different vitamin E-deficient basal diets on hepatic catalase and microsomal cytochromes P-450 and b5 in rats. Male Sprague-Dawley rats maintained for a period of 6 or 12 weeks on a basal vitamin E-dificient diet consisting of 70% sucrose, 20% vitamin-free casein, 4% tocopherol stripped lard, 4% salt mixture, and 2% tocopherol-free vitamin fortification mixture were used to compare two sets of commonly used salt mixtures (salt mixtures USP XIV versus Briggs' salt mixture) and two sets of vitamin fortification mixtures (NBC vitamin fortification mixture versus that of Weglicki). Among the rats maintained on the deficient diets for 6 weeks, only those that received the combination of salt mixture USP XIV and vitamin fortification mixture of Weglicki showed a significantly lower level of hepatic catalase activity compared to the corresponding control animals. While there were no significant changes in microsomal cytochromes at this time period, after 12 weeks on the deficient diet, a significant depression in these cytochromes was noted in all experimental groups except the one on salt mixture USP XIV and NBC vitamin fortification mixture. A similar decrease in hepatic catalase was observed in deficient animals at 12 weeks. Since the most striking differences in these diets are in their content of iron and menaquinone, it appears that these two dietary constituents may interact in modulating the effect of vitamin E on hepatic hemeproteins.


Radiological changes in pica.

Radiological changes in pica. The significance of pica and geophagia as a public health problem is well known. The objective radiographic diagnosis of geophagia depends on the abnormal opacification of the bowel as an immediate manifestitation of the condition. The chance of detectability of geophagia is highest in the colon and can be improved by using low penetration films, particularly for smaller amounts of ingested clay. Other radiologic changes frequently associated with the prolonged practice of geophagic are an atonic pattern of the colon, secondary radiographic changes due to iron-deficiency anemia and bone-age retardation. The occurrences of intestinal obstruction due to pica in the presence of preexisting bowel stricture is demonstrated.


Parenteral magnesium load tests in postpartum American women. The magnesium status of 185 moderate income American mothers was assessed in the immediate postpartum period by the intravenous magnesium load test. Pre- and postload collections of urine were each made for approximately 24 hours because pilot studies revealed significant diurnal variation in magnesium excretion. The magnesium load provided 0.4 to 0.5 mEq of magnesium/kg of estimated lean body weight. The mean retention was 51% +/- 2.2 (SEM). Patients retaining more or less than an arbitrary limit of 40% of the magnesium load were compared. No differences in mean age, weight, or parity were found between the groups. The high retention group reported a diet lower in magnesium and had a significantly lower plasma magnesium value. Magnesium retention of over 90% of the load was found in biologically immature multiparas (less than 17 years) and in young mothers of twins. Among the multiparous patients, those with the longest interval since the previous pregnancy had the lowest retention values. Most of the primiparous patients had met the magnesium requirements of a singleton pregnancy and rejected most of the load, but 6 primiparous women whose active labor exceeded 18 hours had a retention of 77.91% of the load. This was significantly higher than the 45.0 +/- 3.52 (SEM) % retention in 70 primiparous mothers with shorter duration of active labor (P less than 0.005). No other symptoms or complications of pregnancy could be correlated with the magnesium load values. Further definition of the magnesium load test is indicated.


Plasma level and transfer capacity of thiamin in patients undergoing long-term hemodialysis. Water-soluble vitamins have a molecular size small enough to pass through the membrane of an artificial kidney. This fact has led to the suggestion that these vitamins be substituted in patients undergoing long-term hemodialysis. In sharp contrast to this general belief, our study has shown that the plasma thiamin levels in patients on long-term hemodialysis were not different from those found in normal subjects. It also remained unchanged before and after the dialysis, althoug thiamin was obviously removed in in vitro dialysis. Accordingly, dietary thiamin appears to be sufficient, making further supplementation unnecessary.


Effect of diet on serum accumulation and renal excretion of aryl acids and secretory activity in normal and uremic man. The influence of diet on aryl acid metabolism was determined in normal and azotemic subjects. Aryl acid content of serum and urine was estimated by fluorometry in relation to hippuric acid as a standard (FI-Hipp). Secretory activity, a reflection of the biological potency of aromatic acids in serum and urine, was determined by bioassay. The urinary excretion of FI-Hipp and secretory activity of five normal persons on an ad lib diet was 0.78 and 2.25 mM/day, respectively; similar values were observed in two subjects with chronic renal insufficiency. Subjects were fed prunes and cranberries, since these foods contain abundant quantities of hippurate precursors. Prunes 1.5 g/kg body weight, caused the urinary excretion of both FI-Hipp and secretory activity to increase about tenfold in normal and azotemic subjects. Prune feeding caused the serum levels of FI-Hipp and secretory activity to increase about threefold. Cranberries increased the renal excretion of FI-Hipp and secretory activity as did  the ingestion of a beverage containing benzoate as a preservative. On the basis of these studies it is clear that diet is an important determinant of the load of aryl acids for urinary excretion; in patients with renal insufficiency the ingestion of foods containing precursors may cause serum level of biologically active aryl acids to increase strikingly.


Influence of varying energy intake on nitrogen balance in men on two levels of protein intake. Effect of changing energy levels of the diet at constant protein intakes on nitrogen balances in five young men were studied at two levels of protein--40 and 60 g. Nitrogen balance increased with increase in energy intake at both levels of protein. This was brought about primarily by a reduction in urinary nitrogen excretion. Energy levels at which nitrogen equilibrium was obtained were different for the two levels of protein intake. At 40 g protein intake the energy intake required for zero nitrogen balance was 2,249 kcal, while it was 2,066 kcal when the diet provided 60 g protein.


Amino acid composition of the diet in a region of Southern Tunisia. As part of a study of the effects of lysine supplementation of wheat products in Southern Tunisia one qualitative and four quantitative surveys of food consumption were carried out. The average diet provided 7.1 MJ (1,670 kcal), 42 g of protein and 1,280 mg of lysine per person per day. The overall dietary protein thus supplied only 31 mg of lysine/g of protein, or about 56% of the level recommended by the FAO/WHO Expert Committee on Protein Requirements. Addition of lysine to all wheat products to a final effective concentration of 0.2% would raise the dietary lysine level to 45 mg/g protein, or 82% of the FAO/WHO recommended level, at which time threonine would become limiting. Irrespective of whether the FAO/WHO pattern of 1973, breast milk, cow's milk, whole egg or a modification of the FAO pattern of 1957 was used to assess the quality of the protein in the diet, lysine was the first, and threonine the second limiting amino acid (except in comparison with breast milk, which showed tryptophan as the second limiting amino acid). In no case did there appear to be any problem with the sulfur-containing amino acids.


Hydatid disease transmission in California. A study of the Basque connection. A descriptive epidemiologic and anthropologic study was designed to determine by field observation and interview the extent of Basque involvement in the sheep industry of California, the nature of the sheep and dog husbandry practices of California Basques as they might influence Echinococus granulosus transmission, and the "folk knowledge" of hydatid disease possessed by California Basques, particularly as it might indicate the early presence of this infection in California and provide evidence for or against possible intensification or spread of transmission in the recent past. Basques were found to dominate the sheep industry of California's Central Valley from Sacramento south, but to be virtually absent from other sheep-raising areas of the state. In contrast to most other California sheep ranchers, Basques practice a transhumant form of husbandry in which bands of sheep are moved from location to location under the control of contract Basque shepherds from Spain and France and a number of sheep dogs.


The relationship of reported parental history to the incidence of coronary heart disease in the Western Collaborative Group Study. The relationship of a reported parental history of coronary heart disease (CHD) to the incidence of CHD was determined in this prospective study of CHD in an intake population of 39-59-year old men. Reported parental history of CHD was found to be associated with level of schooling, the type A behavior pattern, serum cholesterol and beta/alpha lipoprotein ratio. Men with reported parental history had an increased incidence of angina pectoris in both age defined by symptomatic myocardial infarction and sudden coronary death. Adjustment then was made simultaneously for the confounding effects of the risk factors found to be associated with the prevalence of parental history of CHD. After such adjustment a reported parental history of CHD was still found to have a significant association (p = 0.01) with the combined incidence of symptomatic myocardial infarction and angina pectoris in subjects under 50 years of age.


A new rapid differentiating solubility test for hemoglobin S. A new test for sickling hemoglobin, SickleQuikTM, has been developed which has definitive advantages over existing turbidity tests. This test utilizes a biphasic liquid reagent system provided in individualized, ready-to-use reaction tubes which are stable at room temperature. The test differentiates homozygous from heterozygous S samples in less than eight minutes. Results are based on the color of a layer formed at the organic-aqueous interface and the color of the lower aqueous phase. Of more than 900 samples tested in independent laboratories, no false positive or false negative results occurred.


Developing an integrated, competency-based medical technology program. The authors describe a competency-based, integrated medical technology educational program currently being implemented at Weber State College in Ogden, Utah. Problems associated with the traditional three academic years plus one year clinical education program are described, as well as problems involved in creating new programs. This type of program may prove to be a major advance in the future of medical technology education.


Resident-care practices in institutions for retarded persons: a cross-institutional, cross-cultural study. Institution-oriented and resident-oriented care practices for institutionalized retarded persons investigated in 166 Living units in 19 institutions in the United States and 11 institutions in a Scandinavian country. Living units in the Scandinavian country were found to be more resident-oriented than those in the United States. Large central institutions were characterized by the most institution-oriented care practices, group homes by the most resident-oriented practices, with large and small regional centers falling between these extremes. Within types of institution, care practices were generally homogeneous. Living units for more severely retarded residents were characterized by more institution-oriented practices. Large living-unit size was found to be predictive of institution-oriented practices while cost/resident/day, number of aides/resident, and number of professional staff/resident did not predict care practices. Characteristics of the Child Management Inventory were also examined.


Stimulus input recruitment and stimulus trace decay factors in the trace conditioning deficit of severely retarded young adults. Trace and delay classical eyelid conditioning procedures were used to investigate the relative contributions of conditioned stimulus input recruitment and trace decay processes to the trace conditioning deficit of severely and profoundly retarded subjects. The study included both trace and delay conditioning groups at interstimulus intervals of 500 and 950 msec. The conditioned stimulus durations were 50 msec for the 500-msec interstimulus interval trace group and 500 msec for the 950-msec interstimulus interval trace group. The "empty" interval between conditioned stimulus offset and the onset of the unconditioned stimulus was 450 msec for both trace conditioning groups. After 250 conditioning trials, there was no difference between the two trace groups, and both were significantly below the delay groups in final level of responding. These results suggest that stimulus trace decay rather than input recruitment, as manipulated by varying conditioned stimulus duration, accounts for the poor trace conditioning performance demonstrated by these subjects.


Training correct utensil use in retarded children: modeling vs. physical guidance. Modeling and physical guidance were compared for teaching 24 retarded males (mean age = 13.5, mean IQ = 25.3) to use a knife, fork, and spoon. Initial premeal training methods resulted in no improvement over baseline. The methods were revised to extend throughout meals, and a third method (physical guidance with praise) replaced a former control procedure. Methods involving physical guidance produced significant improvement while modeling did not. All groups then received physical guidance with praise which resulted in their achieving similar levels of performance. Follow-up observations revealed that correct utensil use continued under maintenance conditions.


Infants' home environments: a comparison of high-risk families and families from the general population. Home environments of 30 infants at high-risk for developmental retardation were compared with those of 30 infants from the general population (matched for age, sex, and parity) by means of the Home Observation Measurement of the Environment. Fifteen high-risk infants attended a day-care intervention program; 15 did not. The Home Observation for Measurement of the Environment showed significant differences (ps less than .001) between the high-risk groups and the general population, favoring the general population, on all factors (maternal-warmth, absence of restriction and punishment, organization of the environment, appropriate toys, maternal involvement, and opportunities for variety) but none between the two high-risk groups.


Moral and cognitive development in retarded and nonretarded children. Subjects were 30 cultural-familially retarded and 30 nonretarded children matched for MA within 3 MA levels. The subjects were administered measures of moral judgement and cognitive operations hypothesized by Kohlberg to constitute necessary but not sufficient conditions for attainment of specific moral stages. Moral and cognitive performance improved with MA, but there were no differences between the MA-matched retarded and nonretarded children. Moral judgement related more strongly to MA then to any of the specific cognitive operations tested. The findings failed to support Kohlberg and Gilligan's (1971) hypothesis that the moral judgment of older individuals should be more advanced than that of younger individuals matched for cognitive level, but they were in accord with Zigler's (1969) "developmental" concept of cultural-familial retardation.


Differential effects of four token conditions on rate and choice of responding in a matching-to-sample task. In a two-phase experiment, four different token conditions were presented each session to retarded students in a TMR class. In Phase 1, students responded by matching-to-sample under the following conditions: (A) correct responses produced exchangeable tokens, (B) correct responses produced exchangeable tokens and incorrect responses lost tokens, (C) correct responses produced nonexchangeable tokens, and (D) no-tokens given. In Phase 2, the students chose the condition in which they worked. Results showed that responses cost decreased errors but did not influence correct responding, that each baseline condition produced less correct responding than the token conditions, and that Condition C produced more responding than D. Phase 2 results showed a preference for Condition A and no difference between Conditions B and C. Results were discussed in terms of baselines, response cost, and type of datum.


List organization and rehearsal instructions in recognition memory of retarded adults. The effects of rehearsal training and categorical list organization on recognition memory of mentally retarded individuals was examined. Retention materials were lists of pictures in four taxonomic categories. During acquisition, subjects saw lists organized according to these categories or lists in which category members were distributed randomly. One-half of the subjects were given cumulative-rehearsal training. The remaining subjects were not given rehearsal training. Subjects who were taught to rehearse made fewer errors on the recognition test than subjects who were not taught to rehearse. List organizations did not affect correct responding. We interpreted the data as support for production-deficiency hypothesis.


Reinforcement of cooperation between profoundly retarded adults. An experimental approach to the development and maintenance of cooperation responses in profoundly retarded institutionalized male adults was evaluated in this study. A single-subject reversal design was used for the major experiment which involved automatic recording of cooperative responses. Within a relatively short period, 7 dyads learned independent operation of the cooperation machine. During the first reinforcement period, a high and fairly stable rate of cooperative responding occurred which decreased markedly after several extinction sessions and immediately recovered when reinforcements were reinstituted. The operation of such machines by profoundly retarded subjects resulted in increased social interaction beyond purely mechanistic behavior.


Public attitudes toward mentally retarded children. The recent trend toward integrating mentally retarded children in the community and public school warrants examination of public attitudes toward these children. Factor analysis of equestionnaire responses of 430 adults revealed for factors underlying attitudes toward retarded children: positive stereotype, segregation in the community, segregation in the classroom, and perceived physical and intellectual handicap. Older respondents, parents of school-aged children, and people with no previous contact with a retarded person tended to favor segregation of retarded children in the community. Results of this study suggest that attitudes of these groups must be addressed if retarded persons are to be successfully integrated into society.


Measuring social and prevocational awareness in mildly retarded adolescents. The social and Prevocational Information Battery contains nine subtests measuring social and prevocational awareness. It was developed and normed on secondary EMR pupils in Oregon. The battery is easy to administer, orally presented to eliminate reading ability as a determinant of performance, and relatively simple to score and interpret. Information concerning the standard error measurement and predictive validity inidicates that this battery may be used for pupil screeening, monitoring pupil progress, or for program evaluation.


Effect of experimental success and failure on the situational expectancy of EMR and nonretarded children. The effect of differing histories of success and experimentally induced and failure on the generalized and situational expectancy of EMR and nonretarded children was studied. Three samples of 16 children each served as subjects. The EMR sample was equated with one sample of nonretarded children on the basis of CA and another sample of nonretarded subjects on the basis of MA. Subjects were asked to indicate how well they thought they would do on an experimental task (verbal estimate) and to predict how many out of 8 trials on which they would be successful. Then they were exposed either to experimentally induced success or failure. Subjects were then asked to give a verbal estimate and numerical prediction for a subsequent block of trials. Results failed to support the role of history of success on expectancy; however, the experimentally induced success and failure had a significant effect on both verbal estimates and numerical predictions independent of groups. The results were discussed in terms of social-learning theory, and certain methodological problems in this line of research were noted.


Attractiveness as a biasing factor in teacher judgments. A double-blind experiment to evaluate the effect of facial attractiveness on teacher judgments was performed. Given identical information, teachers systematically rated attractive children more favorably than unattractive children. In the case of unattractive children, teachers were more willing to recommend special-class placement and held lower expectations for future academic and social development.


Effects of letter-reversals training on the discrimination performance of EMR children. Ninety mentally  retarded elementary-school children who committed letter-reversal errors on a pretest were randomly assigned to one of three (one experimental, two control) training conditions consisting of seven sessions given over a 5-week period. Subsequent statistical analyses revealed that for one of four letter-discrimination posttests, the experimental subjects performed significantly better than the placebo control subjects. Differences between the experimental and the method-specific control subjects were in the expected direction but not statistically significant. Aptitude times Treatment interactions for three of the four posttests revealed the training effect to be most pronounced with younger and more retarded children.


Current aspects of sterilization. The selection and application of various surgical methods of sterilization. A partial analysis of 4,270 female sterilizations performed during a 7 year time period was described as related to changing patterns of application according to a sterilization program. Special attention was given to such factors as type of procedure, reasons for selection of procedures, ancillary conditions, mortality rate, and follow-up. A plea is made for accuracy when a sterilization is truly used as the primary indication for surgery and for flexibility and individualization in the application of sterilization techniques.


Obstetricians and nurse-midwives: The team approach in private practice. Much has been written about the need for help for the overworked obstetrician. Two obstetricians delivering over 500 babies annuallay had insufficient time for their gynecology practice. Two nurse-midwives were employed and in the first year they delivered 61 per cent of those patients who delivered vaginally. All normal patients had the privilege of choosing their accoucheur; patients, nurse-midwives, and obstetricians were very well pleased with the team approach.


Serum prolactin levels in galactorrhea.

Serum prolactin levels in galactorrhea. Some patients with galactorrhea will have normal serum prolactin levels but many will have elevated serum prolactin levels. The galactorrhea may be due to drug ingestion, nipple afferent nerve stimulation, nonneoplastic disease or injury, and intracranial tumors. Serum prolactin levels were measured by radioimmunoassay in 17 women with galactorrhea. Levels 5 and 6 times normal values were found in two women who had proved pituitary adenomas. The latter conditions must be strongly considered and functional tests may help in diagnosis prior to enlargement of a prolactin-secreting tumor to the size where changes in the sella are seen on x-ray or visual field changes occur. If galactorrhea persists when no evidence of tumor can be found, the patient must be periodically re-evaluated, as the tumor may have been too small for detection at the time of the previous examination.


The prevention of postoperative pulmonary emboli with low-molecular-weight dextran. The effect of low-molecular-weight (LMW) dextran as a prophylactic agent in the prevention of pulmonary emboli and deep vein thrombophlebitis was evaluated. Eighty-seven patients were given LMW dextran during and after surgery on a predetermined schedule during the study period. These 87 patients were compared to 103 patients who, in the previous year and a half, received no pharmacologic prophylaxis. In the dextran group there was one suspected pulmonary embolus, no case of deep vein thrombophlebitis, and no death. In the control group there was one case of deep vein thrombophlibitis, seven cases of pulmonary emboli, and three deaths directly attributable to pulmonary emboli.


Puerperal inversion of the uterus.

Puerperal inversion of the uterus. Acute puerperal inversion of the uterus is an uncommon but potentially fatal obstetric complication. In the 15 year period ending December 31, 1974, 11 inversions have been managed at the University of Virginia Hospital. All were recognized immediately and manually replaced and there was no significant postpartum morbidity. Successful management appears to depend largely upon prompt recognition, which can be achieved by routine postpartum examination of the vagina and cervix and manual exploration of the uterus.


Major gynecologic surgery in the elderly female 65 years of age and older. A total of 185 cases were reviewed of major gynecologic surgery performed upon women 65 years of age and older from 1970 to 1973 at a 350 bed community hospital. Each private staff physician operated upon his private patient. There were 112 vaginal operations performed, mostly for pelvic relaxation problems, and 73 abdominal operations. Forty-two patients had surgery for cancer. There were nine postoperative complications and only two deaths. It can be concluded from this study that the elderly female can tolerate major gynecologic surgery very well in a modern-day hospital setting.


Sickle-cell trait and pregnancy: A review of a community hospital experience. The obstetric experiences of 128 gravidas delivered at Charlotte Memorial Hospital in 1973 who, on hemoglobin electrophoresis, exhibited an SA pattern of hemoglobin are reviewed. In addition to previously reported complications of increased rates of pyelonephritis and refractory anemia, this group of patients exhibited a marked increase in premature rupture of membranes and prematurity. It is suggested that the routine screening procedures be used for discovering sickle-cell trait individuals and that they be categorized as "high-risk" obstetric patients because of the increased complication rates described here and by previous authors.


The relationship of medical specialization (obstetricians and general practitioners) to complications in pregnancy and delivery, birth injury, and malformation. In this paper, census data were used to assess the effectiveness in birth delivery of obstetricians and general practitioners.though the data reported require some qualification and additional research, preliminary results indicate that general practitioners report approximately three times more birth injuries and/or malformations (than do obstetricians) at birth. Both groups (obstetricians and general practitioners) report approximately the same number of complications in pregnancy and delivery. It was tentatively concluded that the similarity in diagnosed complications was probably due to diagnostic error. This error, in combination with sample differences and differing delivery techniques, resulted in the consequent differences in rates of birth injury and malformation.


Impact of betamethasone load given to pregnant women on endocrine balance of fetoplacental unit. Corticosteroid administration to pregnant women for attempted prevention of the respiratory distress syndrome in infants (IRDS) involves the hazard of seriously altering the endocrine status in the fetoplacental unit. The effect of a betamethasone load (12 mg. daily for three days) to 19 pregnant women in the last trimester was studied, and a comparison was made with 13 control subjects. Amniocentesis was performed twice in most patients. There was a sharp reduction of cortisol in maternal serum and a significant decrease in cortisol concentration in amniotic fluid (p less than 0.05) after betamethasone treatment. Maternal urinary estriol excretion decreased; this was strongly correlated to the basal estriol excretion (r equals 0.945). A residual fraction of estriol excretion, not less than 2 mg. per 24 hour urine specimen, remained despite the high corticosteroid dose. The origin of the nondepressed part of urinary estriol might be multifactorial, e.g., nonadrenal production of estriol precursors and functional inhomogeneity of the fetal adrenal in response to adrenocorticotropic hormone stimulation. The corticosteroid treatment for prevention of IRDS transiently excludes the use of urinary estriol for assessment of fetoplacental integrity but does not influence the plasma level of human chorionic somatomammotropin.


Respiratory function in pregnant obese women. Lung volumes and other ventilatory variables were measured in 10 women with a mean age of 28 years, a mean height of 163 cm., and weights which were 50 to 140 per cent above the normal. Measurements were made during the last trimester of pregnancy and after the second month postpartum. Mean values of lung volumes in liters during these two time periods were: vital capacity (VC), 3.7 and 3.92; expiratory reserve volume (ERV), 0.79 and 0.94; functional residual capacity (FRC), 2.06 and 2.14; and forced expiratory volume at one second (FEV1) 3.2 and 3.3. Mean blood gas values were as follows: pH, 7.44 during both times; PaCO2, 29.7 and 35 torr; standard bicarbonate, 22 and 28.8 mEq; base excess, -4.2 and 0.03 PaO2 breathing air, 85 and 86 and breathing 100 per cent oxygen, 527 and 515 torr; AaDO2, 162 and 167 torr. We conclude that, with the exception of FRC, pregnant obese women who are 50 to 140 per cent overweight develop respiratory changes similar to those seen in normal-weight gravidas. These findings suggest that obesity of this magnitude does not exaggerate changes in ventilation induced by pregnancy as generally believed. Why in this obese population the decrease in FRC during pregnancy did not occur to the same degree as that seen in normal-weight gravidas cannot be defined from our study. Evidence is presented for a ventilation/perfusion imbalance in obese subjects which is not corrected during pregnancy.


Uterine contractility data processing system. A versatile system has been developed for off-line computerized quantitation of uterine contractility. It includes tabulation and display of intensity, frequency, resting tone, uterine activity, cumulative area below the pressure curve, and average intrauterine pressure. Its advantages and drawbacks are compared with the conventional method and with an automated on-line labor surveillance system.


Steroid metabolism of fetal tissues. II. Conversion of androstenedione to estrone. The conversion of androstenedione to estrone in various tissues of 13 human fetuses ranging from 9 to 40 weeks of gestation was measured by a double isotope method in vitro. The data revealed differences in aromatization between cerebrum and hypothalamus. For hypothalamic tissue the conversion rate ranged between 0.01 and 1.40 per cent and for cerebral tissue between 0.00 and 0.07 per cent. The highest rate of conversion was found in liver tissue. Adrenal, kidney, lung, thymus, heart, skin, and gut were also examined and the results are compared with data in the literature.


Cervical neoplasia in residents of a low-income housing project: an epidemiologic study. In 1969, a published report estimated that the incidence of cervical cancer in a low-income housing project in Atlanta, G Georgia, might be of epidemic proportion. In 1971, we surveyed this housing project to determine if the prevalence rate of cervical neoplasia was unusually high during the period January, 1969, through September, 1971. From the survey we determined the number of women at risk for cervical neoplasia, and we determined the number of women who had cervical neoplasia from the Tumor Registry at Grady Memorial Hospital. The over-all cervical dysplasia rate was 63/1,000. The over-all prevalence rate of cervical carcinoma in situ was 11/1,000. These rates were compared with rates in two studies which also dealt with the prevalence of cervical neoplasia in low-income black populations. The rates in all three studies were comparable. We conclude that the high rates do not necessarily signify an epidemic, but we suspect that the prevalence of cervical neoplasia in low-income black women is much higher than previously estimated.


The source of estradiol-17beta in trophoblastic neoplasia. Unconjugated and conjugated estradiol-17beta (E2) were measured in the sera of four patients with hydatidiform mole at frequent intervals after removal of the mole, in the left and right ovarian vein blood in a patient with hydatidiform mole, in the peripheral sera and serous fluid of the molar vesicles in seven cases of hydatidiform mole, and in the fluid from the left and right theca lutein cyst (TLC) of a molar pregnancy, by a radioimmunoassay method. Patients with highly elevated serum E2 had a rapid clearance of E2 within 24 to 36 hours after removal of the mole; those with minimal E2 elevation had a slower clearance of the hormone from the circulation. Mole vesicle fluid had undetectable E2 but a wide range of unconjugated E2 which was usually lower than in the peripheral blood. Both ovarian vein blood and TLC fluid have higher E2 concentrations than the peripheral blood. The significance of these findings is discussed in relation to the contribution of the trophoblast and the ovaries to the circulating E2.


Quantitation of antigens in normal and malignant ovarian tissue. Evidence is presented that at least one of the antigens of human ovarian cancer tissue which appeared to be tumor-associated in immunodiffusion and immunoelectrophoresis experiments actually represents a quantitative rather than a qualitative difference between normal and malignant tissue. A glucoprotein band (Rf equals 0.01) believed to contain at least one tumor-associated antigen was isolated by disc-gel electrophoresis with 5.6 per cent SDS-acrylamide and was used to immunize rabbits. Immunodiffusion and immunoelectrophoresis experiments with the resulting antiserum indicated that the glycoprotein band contained two antigens, one which was present in normal extracts at a concentration approximately one tenth of that in tumor extracts and another which was detectable only in tumor tissue. The tenfold difference between normal and tumor tissue was confirmed by studies of the appearance and disappearance of the glycoprotein band when acrylamide gel electrophoresis was performed on varying amounts of normal and tumor extracts.


Evaluation of diagnostic ultrasound in gynecology. The experience with 300 consecutive gynecologic patients undergoing diagnostic ultrasound has been evaluated. Follow-up was obtained by recording the clinical course and/or the operative findings. The ultrasound studies were diagnostic in 21 per cent, confirmatory in 74 per cent, and misleading in 5 per cent of the patients. Certain conditions lend themselves to diagnosis with ultrasound: hydatidiform mole, intrauterine pregnancy, dermoid cyst, ascites, simple ovarian cyst, and lost intrauterine contraceptive devices (IUCD's). The studies in patients with chronic pelvic inflammatory disease or adhesions were occasionally misleading. Diagnostic ultrasound was particularly helpful in the obese patient, in whom adequate pelvic examination was difficult.


Oxytocin challenge test.

Oxytocin challenge test. This study reviews the indications, interpretation, and practical application of the oxytocin challenge test (OCT) in 154 patients undergoing 375 tests. It emphasizes aspects of technique which may make the "challenge" nonphysiologic and the stress, therefore, nonquantifiable. Thirty-four positive or suspicious tests were obtained in 22 patients. These results are correlated with clinical complications of pregnancy; antepartum indices of fetal well-being (estriol, ultrasonic serial cephalometry, and the presence of meconium on amniocentesis); and subsequent intrapartum fetal heart rate response. Unsatisfactory (47 in 23 patients), false-positive, and false-negative tests are reviewed in detail. Since false-positive tests (47.9 per cent) are common whereas false-negative tests are rare (2.8 per cent), we conclude that the negative test is a reliable indication in high-risk pregnancies. Positive tests add to out data on the fetus and alert us to the need for a totally monitored labor.


Clinical significance of fetal heart rate patterns during labor. II. Late decelerations. Among a population of high-risk patients in labor who had continuous "direct" electronic monitoring, 147 presented late decelerations and 598 had no decelerations at the time the first stage was completed, or a cesarean section decided upon. A variety of clinical aspects of mother and fetus were analyzed, considering some alterations observed in the FHR pattern. Apgar scores were lower among decelerations, and there was a negative correlation between these two. Maternal pathology, other than PRM, was higher among decelerations and these required enhancement more often. There was very high association with tachycardia, saltatory, and fixed baseline among decelerations, and these infants were very often distressed and born depressed. Within the group of decelerations, small fetuses had lower Apgar scores. There was a negative correlation between number of decelerations and Apgar score. The small fetuses had a high incidence of tachycardia and fixed baseline, saltatory being almost absent. Their neonatal outcome was poor. A comparison of fetal response to distress was done considering age of gestation (premature, term, and postmature) and found to be different. The mechanisms involved in late deceleration are discussed, reviewing the published experimental work. When interpreting FHR patterns, age of gestation should be one of the most important considerations.


An etiologic and pathogenetic classification of male hermaphroditism. Based on defects in the central nervous system, the gonads, the end organs and the chromosomes, an etiologic and pathogenetic classification of male hermaphroditism is presented. At least 16 categories of disorders can cause male hermaphroditism--all seem to be basically genetic in origin.


Bladder dysfunction after Schauta hysterectomy. One-year follow-up. The purpose of this study was to determine the long-term effect of Schauta hysterectomy on bladder function as determined by serial cystometric studies. The maximum bladder capacity, resting pressure at maximum capacity, and volume of residual urine were determined preoperatively, postoperatively, at time of final catheter removal, and one or more years after surgery. A prior report showing that the bladder decreased in capacity, increased in tone, and, emptied poorly if at all postoperatively was confirmed. The mean duration of postoperative catheter drainage in 68 patients was 33 days. One year or more after surgery the mean maximum bladder capacity had returned to the preoperative volume; persistent elevation of the mean resting pressure was significant in the pooled but not in the paired data; the mean residual urine volume of 25 ml. was significantly elevated. The assumption was that maintenance of intrinsic detrusor muscle tone by prevention of overdistention preserved balanced bladder function. Many patients initiated and maintained micturition by voluntary straining or by use of Crede's maneuver although others voided relatively normally. Presumably these bladders are denervated to varying degrees, producing a spectrum of functional disturbance. The "bladder-conscious" patient can protect and preserve bladder function but these bladders appear to remain vulnerable to infection and overdistention, perhaps permanently.


Radical hysterectomy or radiotherapy for stage I cervical cancer. A prospective comparison with 5 and 10 years follow-up. A prospective study of the treatment of 119 patients with Stage I carcinoma of the cervix by radical hysterectomy alone (58 patients) or radiotherapy alone (61 patients) was undertaken between Jan. 1, 1956, and May 31, 1966. Eighty-one per cent of the patients treated by radical hysterectomy survived 5 years as compared with 74 per cent of those treated by radiotherapy. The 10 year survival rates were 75 and 65 per cent, respectively. These differences were not statistically significant. Complications of treatment were relatively few except for a greater incidence of urinary tract problems after surgical treatment; most of these were resolved with restoration of normal function. When recurrence occurred in the surgical series further treatment by radiotherapy offered a reasonable prospect of survival. Failure of radiotherapy left relatively little opportunity for later treatment by operation.


Standardized treatment of 154 consecutive cases of eclampsia. Since 1955 standardized treatment applied uniformly to all cases of eclampsia at Parkland Memorial Hospital has consisted of (1) magnesium sulfate intravenously and intramuscularly to control convulsions, (2) intravenous hydralazine intermittently to lower diastolic blood pressure when it exceeded 110 mm. Hg, and (3) steps to effect vaginal delivery as soon as the woman has regained consciousness. The dosage schedules for magnesium sulfate and hydralazine, while empiric, have been extensively tested for both efficacy and toxicity. Delivery usually was accomplished vaginally and conduction anesthesia was avoided. Neither diuretics nor osmotic agents in the form of hypertonic glucose, mannitol, or albumin were used to treat eclampsia. Heparin was never given. To date 154 cases of eclampsia have been so treated with no maternal death. All fetuses alive when treatment was started and weighing 1,800 Gm. (4 pounds) or more survived. The results provide a standard against which new drugs and treatment regimens can be compared.


Acute macular neuroretinopathy.

Acute macular neuroretinopathy. An unrecognized acute macular affection occurred in four women, 24 to 35 years old, using oral contraceptives who complained of a sudden decrease of visual acuity or paracentral scotomas. Three patients had bilateral lesions and one patient had unilateral lesions. These lesions consisted of darkish brown-red, wedge-shaped dots in the macula pointing to the fovea. These dots were located mostly on the nasal side to the macula. Biomicroscoby showed these lesions were located in the superficial layers of the retina. The retinal vessels, pigment epithelium, and optic disk showed no distinct pathologic features. Fluorescein angiography, performed repeatedly, showed some questionably dilated perimacular capillaries without leakage in two cases. Static perimetry delineated dense paracentral scotomas. Recovery was slow or absent, confirmed py perimetric observation. Ophthalmoscopic, fluorescein angiography, and perimetric details excluded an affection of the pigment epithelium, the nerve fiber layer, and the optic disk. Since the affection appears to be localized superficially in the retina, we called this specific entity acute macular neuroretinopathy.


Progressive external ophthalmoplegia associated with retinal pigment epitheliopathy. The diagnosis of ocular myopathy associated with a primary retinal pigment epitheliopathy in a 20-year-old man was based on the integrity of the retinal functions, despite progressive worsening of muscular activity in the systems affected by the disease, and on the results of retinal fluorescein angiography. Although the changes in the pigment epithelium were not prominent ophthalmoscopically, they were clearly visible angiograpically. Atypical forms of retinal pigment dystrophy occurring during the course of ocular myopathy appear to be clinical expressions of a unique genetic defect confined to the pigment epithelial layer. We assume that the gene is capable of inducing a pleiotropic effect.


The pleomorphism and complications of posterior hyperplastic primary vitreous. Among 30 patients examined, posterior hyperplastic primary vitreous was monocular in 25 and binocular in five. Poor vision and strabismus were the most common presenting complaints. All patients had vitreous membranes usually extending from the disk toward the equatorial zone. In 70% of the affected eyes, the vitreous membranes were associated with a radial retinal fold. Macular function was disturbed in 70% and retinal detachment was observed in 45% of the eyes. One extensive retinal detachment was successfully treated by scleral buckling; another detachment, limited to the posterior pole, responded to sectioning of a vitreous band with scissors.


Pigmented paravenous retinochorodial atrophy. Three male patients had paravenous pigmented retinochoroidal atrophy. Extensive retinal function tests showed characteristic retinal pigment epithelial abnormalities on fluorescein angiography, loss of peripheral visual field, diminution of the electroretinographic b-wave, and elevated rod threshold on dark adaptometry. The disease appears to be more progressive than previously indicated, and in late stages, may cause legal blindness through involvement of the posterior pole. No treatment is known.


Specific histocompatibility antigens associated with Behçet's disease. We studied the distribution of HL-A antigens in 44 patients with Behcet's disease and in 78 normal control subjects. The antigen frequencies of HL-A5 and 4c were significantly increased in the patients (HL-A5: chi2=22.1, P  less than 0001; and 4c: chi2=26.9, P less than .0001).


Traumatic central retinal artery occlusion with sickle cell trait. An 8-year-old black boy with sickle cell trait struck his left brow and globe on the edge of a table and had immediate blurring of vision. Six days later visual acuity was light projection, and traumatic iritis with secondary glaucoma and perimacular edema were present. Fluorescein angiography indicated obstructed peripheral and perimacular arterioles and dye leakage from the disk.


The histopathology of Peters' anomaly.

The histopathology of Peters' anomaly. Corneal, iris, and trabecular meshwork tissue in a 23-month-old boy with Peters' anomaly were studied with light and electron microscopy. In the cornea, both Descemet's membrane and endothelium were present beneath the area of the corneal opacity except at the point of iris adhesion. However, Descemet's membrane was thin and embryonal in nature, and the endothelium markedly attenuated. The trabecular meshwork demonstrated changes characteristic of old age such as wide-banded collagen and the presence of phagocytosed pigment granules in the endothelium. The iris appeared normal except for anterior synechiae to the corneal opacity. Developmentally, the primary fault appeared to be a failure in the normal differentiation of endothelial cells of the cornea and trabecular meshwork.


Hemolytic glaucoma.

Hemolytic glaucoma. The clinical manifestations of hemolytic glaucoma in five patients showed that the glaucoma began after a large intraocular hemorrhage. Gonioscopy revealed open angles in the anterior chamber and reddish-brown pigment covering the trabecular meshwork. Numerous red-tinted blood cells were floating in the aqueous humor; some of these were macrophages found by cytologic examination to contain golden-brown pigment granules. The presumed cause of hemolytic glaucoma is obstruction of the trabecular meshwork by fragments of hemolyzed red blood cells and hemoglobin-laden macrophages. Two patients, whose intraocular pressures were not decreased with medication, improved remarkably after irrigation of hemolytic debris from the anterior chamber.


Surgical landmarks in trabecular surgery. Clinical and histologic studies in 40 eyes of 35 patients with chronic open-angle glaucoma or chronic angle-closure glaucoma operated by various types of "trabeculectomies" were assessed to evaluate whether success was correlated with the surgical approach or with the presence of trabecular tissue in the pathologic specimen. It was clearly demonstrated that it is not necessary to localize or enter Schlemm's canal in order to perform  successful trabeculectomies; it is not necessary to operate posterior to the scleral spur; and it is not necessary to excise either Schlemm's canal or trabecular tissue to achieve success. In essence, trabeculectomies primarily function as fistulizing operations carried out under scleral flaps substituting a scleral-conjunctival barrier to aqueous flow rather than the conjunctival barrier alone provided by standard glaucoma operations. This greater obstruction explains the absence of shallow chambers, the reduced incidence of polycystic bleb formation and, perhaps, an avoidance of long-term complications that often result from these two factors.


Effect of retinal detachment surgery on the course of preexisting open-angle glaucoma. In 11 of 12 eyes with chronic simple glaucoma after surgery for retinal detachment, intraocular pressures were decreased for one to 5 1/2 years without any antiglaucomatous treatment. No further deterioration in the state of the optic disks or the visual fields occurred in any of these eyes. In all 12 fellow eyes antiglaucomatous treatment is still being administered. The operation employed in nine of the 11 cases consisted of an encircling silicone rubber band shortened by 15 to 20% of its length when placed around the eyeball before tapping subretinal fluid. An episcleral silicone implant was placed under the encircling ban in seven of these eyes. Kinking and possibly narrowing of the long posterior ciliary arteries by the encircling silicone band probably caused the ciliary hyposecretion and the resultant hypotony.


Monocular diplopia in flying personnel.

Monocular diplopia in flying personnel. Fifteen cases of monocular diplopia or polyopia in U.S. Air Force flying personnel appeared due to optical aberrations of physiologic variations within the refracting elements of the eye. In most cases, this symptom was compatible with excellent visual acuity and was not regarded as a detriment to safe and accurate visual performance.


Transillumination of the angular and frontal veins. A 500-W fiber optics cold light used to transilluminate the angular and frontal veins allowed quick, accurate delineation of the veins for percutaneous orbital venography. It also allowed the surgeon to avoid cutting the angular vein when operating on the lacrimal sac.


Vitreous scissors and forceps.

Vitreous scissors and forceps. Vitreous scissors with bent blades and forceps of larger than usual dimension were developed for removal of inflexible membranes and intraocular foreign bodies.


Follow-up study on upper extremity bracing of children with severe athetosis. This paper describes the results of a follow-up evaluation of a bracing program for severely athetoid, mentally retarded children. Bracing to improve upper extremity control was started in 1968 and was described in a 1971 AJOT article. The follow-up study was done in order to provide criteria for selecting patients in future bracing programs, to identify the type of motion problems that could be successfully braced, and to determine the bracing configurations most effecive in aiding arm control.


Four models in imparting decision-making information. Twenty-four students in a basic professional master's program were asked to assign muscle test grades after being given a description of the performance of a hypothetical patient. Each student used one of four experimental formats for presenting the decision-making information necessary to assign the muscle grades. None of the students had been previously exposed to the information and the speed and accuracy of their performance was measured. No differences were noted in accuracy regradless of the format used but the flow chart and the logic tree formats were significantly more efficient in terms of time. The algorithm format was significantly less effective on the time dimension. The prose format was intermediate with regard to time.


Attitudes of graduates toward occupational therapy education. Recently graduated occupational therapists were surveyed to determine their perceptions of the adequacy of their professional training. Through a mailed questionnaire, therapists evaluated their undergraduate professional preparation based upon their clinical experiences since graduation. Additional suggestions were solicited regarding possible areas of curriculum change, and the survey gave special attention to the area of interpersonal skill development. Responses were examined for areas of commonality and possible use in curriculum planning and modification. Results indicated that recent graduates see a need for more and earlier patient contact, increased attention to the development of administrative and managerial skills, and courses designed to facilitate skills necessary for effective interpersonal relationships.


The Pavlik harness for congenital dislocated hips. The use of the Pavlik harness for treatment of congenital dislocated hips was begun at The University of Texas Medical Branch at Galveston, Texas, in August 1973. A method for rapid measurement and construction was subsequently developed. Data on length of use and case studies are presented.


The basis for corneal shape change during contact lens wear. Trials were conducted in which subjects wore various contact lenses while their corneas were exposed to gases of varying oxygen content. Measurements of central and peripheral corneal thickness and corneal topography show that corneal topography changes after contact lens wear can have at least two causes, an unevenly distributed corneal thickness change and/or a mechanical molding of the shape.


Patterned and unpatterned visual evoked responses in strabismic and anisometropic amblyopia. The VERs of 12 strabismic and anisometropic amblyopes were studied using unpatterned stimuli varied with respect to intensity, wavelength and frequency, and also patterned stimuli. While the unpatterned stimulus conditions did not differentiate between amblyopic and non-amblyopic eyes, VERs elicited by small checkerboard patterned stimuli were significantly reduced in amplitude in amblyopic eyes (p less than 0.01); however, there was no relationship between the reduction in visual acuity and that of the VER amplitude. VER latencies were not significantly different in amblyopic and non-amblyopic eyes across all stimulus conditions.


Corneal thickness changes from bathing solutions. Corneal thickness changes were measured after bathing the outer corneal surface with sodium chloride solutions of various concentrations. Bathing was accomplished by total immersion in the solution in a goggle or by the application of drops for a period of 20 minutes. A nearly linear relationship was found between hypotonicity and the degree of corneal swelling.


Corneal curvature and supplemental power effect of the Bausch and Lomb SOFLENS contact lens. The supplemental power effect (SPE) of F series Bausch and Lomb SOFLENS (polymacon) Contact Lenses was determined for a sample of 54 eyes. The mean value was +0.34 D=S.D.+/-0.37 D, range zero to +1.00 D. A significant correlation was present between the SPE and the apical lens-cornea bearing relationship. (p less than 0.01). The results of this study provide refractive evidence that a central lens-cornea alignment is achieved when the posterior apical radius of the lens is about 0.5 mm flatter than the flat radius of the cornea, S.D.+/-0.35 D. This information is clinically useful in assessing the patient's visual response as well as the fit of the lens.


Exophoria at near in presbyopia.

Exophoria at near in presbyopia. The exophoria at near working distances through a plus lens addition which exists in presbyopia was investigated in order to explain the paradoxical lack of asthenopic symptoms associated with this condition. Fixation disparity measurements indicate that the exophoria which is measured by the von Graefe technique does not exist under binocular conditions. Further analysis indicates that presbyopes may have unrestrained use of accommodative convergence.


Variations in refractive change induced by Cyclogyl upon children with differing degrees of ametropia. The effect of cycloplegic drugs on refraction is complicated by the presence of many variables. This study is concerned with one of these: the type and degree of refractive error. A manifest and a cycloplegic refraction were performed on 170 eyes. The difference was determined in each case and tabulated according to the type of ametropia. This experiment showed that in every instance the cycloplegic estimate was equal to or greater in hyperopia or less in myopia than when performed without drugs. The greatest difference occurred in hyperopia, decreasing to zero once myopia was reached.


Soft lens power and curvature: a comparison of "label" and observed measurements. Determining the concave curve by a projection method, 350 spin cast lenses were compared with information published by the manufacturer. The power was also determined, using Sarver's method, to establish the clinical reliability of label powers. An equal number of lathe cut lenses were subjected to the same tests. Results indicated that spin cast lenses are very nearly as described in the manufacturer's published information. The lathe cut lenses involved in this study were not as dependable. Variations in the power of "C" series lenses and other related observations are also reported.


The utilization of a consulting clinical psychologist within an urban vision training clinic. Multi-disciplinary evaluation of children with learning problems is necessary in many cases. The private optometrist frequently has psychological resources available to him and his patients. In an urban setting with an inner city patient population, the clinical practitioner has much difficulty in referring and in retrieving psychological data. The function of a consulting psychologist as an attending staff member of the Visual Training Department of the Optometric Center of New York is described, and a preliminary report of 52cases referred for psychological consultation between September 1, 1972 and June 30, 1973 is presented.


Volume changes induced in rabbit polymorphonuclear leukocytes by chemotactic factor and cytochalasin B. Incubation of rabbit neutrophils with various chemotactic factors causes an expansion of their volume. The expansion shows a high correlation with the chemotactic responsiveness of these cells, requires metabolic energy, and is independent of the presence of divalent cations. Cytochalasin B causes a decrease in the volume of the neutrophil. This decrease also requires metabolic energy and is independent of divalent cations. In the presence of cytochalasin B, the chemotactic factor, instead of acting to expand cell volume, induces a further contraction of the cell; this decrease requires Ca2+ in the external medium.


Massive obesity and the kidney. A morphologic and statistical study. The renal morphology of 5 grossly obese patients with normal renal function and many of the features of the Pickwickian syndrome was studied at autopsy. The most striking feature was that of increased glomerular size. Measurements of two parameters of glomerular areas indicated statistically significant glomerular enlargement for both as compared to controls. Glomerulomegaly was primarily the result of vascular dilatation and a variable mesangial component. This abnormality was related to several factors, including increased blood volume, hypoxia, and increased right ventricular pressure. Polycythemia, commonly noted in other similar conditions with glomerulomegaly, is believed to be of no importance in the pathogenesis of glomerular enlargement.


The aortic intima. II. Repair of the aortic lining after mechanical denudation. This article reports the ultrastructure of the aortic lining during the repair of mechanically denuded aortic intima in the rat. Three main features were observed: a) Although platelets form a pavement on the exposed components of the aortic intima, platelet thrombi do not form on the denuded surface. b) During the first weeks after injury, a temporary false endothelial lining is formed by modified intimal smooth muscle cells. While the modified smooth muscle cells do not constitute a continuous cell layer, they are like true endothelial cells in that platelets do not adhere to the cell membrane of either cell type. c) A continuous layer of true endothelial cells is formed within 2 months after the original injury. Even after reestablishment of a continuous endothelium, however, abnormalities persist in the form of incompletely formed intercellular junctions. This abnormal endothelium is associated with areas of intimal smooth muscle cell proliferation. These observations are compatible with two alternative interpretations of the role of endothelial injury in the intimal proliferation seen following injury to the vessel wall: a) persistent defects in the endothelium may result in proliferation of underlying arterial smooth muscle cells or b) the proliferation, in converse, may in some manner delay the healing process of the overlying endothelium.


Cell injury with viruses.

Cell injury with viruses. The inhibitions of cellular protein and RNA synthesis in picornavirus-infected cells are early events which require only limited synthesis of virus-specific proteins. The inhibition of cellular protein synthesis appears to be due to blocking of the association of ribosomes with host messenger RNA. Inhibition of cellular RNA synthesis involves inactivation of the template-enzyme complex and affects ribosomal RNA synthesis before messenger RNA synthesis. Inhibition of cellular DNA synthesis also occurs early and may be secondary to inhibition of cellular protein synthesis. Early chromatid breaks may be related to inhibitions of cellular protein and nucleic acid synthesis. Stimulation of phospholipid synthesis in picornavirus-infected cells also requires only limited synthesis of virus-specific proteins. In contrast, release of lysosomal enzymes, proliferation of smooth cytoplasmic membranes, cellular vacuolization, retraction, and rounding, and diffuse chromosomal changes related to karyorrhexis and pyknosis are all dependent on considerable synthesis of virus-specific proteins during the middle part of the picornavirus growth cycle. The early virus-induced alterations in cellular biosynthetic processes are not the direct or sole cause of the subsequent marked pathologic changes in the membranes and chromosomes of the cell.


Ischemic tissue injury.

Ischemic tissue injury. The subendocardial to subepicardial gradient in the severity of ischemia following acute coronary occlusion is described. The effects of mild, moderate, and severe ischemia on cell structure and function are compared in summary form, and special attention is given to the effects of severe ischemia on myocardial cells. The characteristics of reversible and irreversible ischemic injury are defined in biologic terms. The failure of cell volume regulation in cells which have entered an irreversible state of ischemic injury is demonstrated by the use of free-hand slices in vitro. Irreversibility is associated with structural defects in the plasma membrane and is reflected in an increased slice inulin-diffusible space, increased slice H2O and Na+ content, and failure of the tissue to maintain the high K+ and Mg2+ levels characteristic of normal left ventricular myocardium. Defective cell membrane function is an early feature of irreversible ischemic injury and may be a primary event in the genesis of the irreversible state.


The lethal actions of antitumor agents in proliferating cell systems in vivo. Antitumor agents cause selective lethal injury in tissues in which there is high proliferative activity. It is a reasonable postulate that the selective pathology is the consequence of interference with the replication of DNA in mitotically active cells. The crypt epithelium of the small intestine of rodents, which is highly susceptible to injury by antitumor agents, has served as a useful object for in vivo study of the relationship between inhibition of DNA synthesis and cell death in proliferating tissues. The lethal effects of highly selective inhibitors of DNA synthesis, such as hydroxyurea and 1-beta-D-arabinofuranosylcytosine, develop rapidly and are restricted to those crypt cells which are committed to DNA synthetic activity. Agents like methotrexate, which concurrently suppress DNA, RNA, and protein synthesis, induce more slowly developing and more persistent alterations. As illustrated in mice treated with 1-beta-D-arabinofuranosylcytosine and polyinosinic-polycytidylic acid, the necrotic process in intestinal epithelial cells involves rapid envelopment of degenerating organelles in cytolysomal vacuoles.