Creatine phosphokinase release as a measure of tourniquet effect on skeletal muscle. In anesthetized dogs, a pneumatic tourniquet was applied to a hind limb for one, two, or three hours. Resultant ischemic damage to skeletal muscle was assessed by creatine phosphokinase (CPK) levels in the femoral venous blood of the experimental limb after the tourniquet was released. The CPK levels did not rise after release of one-hour occlusion in three experiments. The elevation of CPK values was demonstrated after occlusion for two hours in three of four experiments, and after occlusion of three hours in all four experiments. When a three-hour occlusion was interrupted for 15 minutes after each hour in three experiments, elevation of CPK levels was minimal or absent. Thus, skeletal muscle injury, as measured by the level of venous CPK elevation, becomes apparent after two to three hours of occlusion and can be prevented by short periods of recirculation.


Experimental evaluation of primary repair of colonic injuries. To evaluate the management of colonic injuries, experimental models simulating acute injuries of the colon were studied utilizing New Zealand white rabbits. Seventy-nine rabbits underwent primary repair of colonic injuries in the presence of massive contamination and none showed any evidence of anastomotic leakage or breakdown. The fact that primary colonic repairs do heal even in the presence of infection suggests that breakdown of colonic anastomosis results from factors other than infection. Despite the absence of anastomotic leaks in this series, morbidity and mortality were high in those animals not given antibiotics. The high morbidity and mortality were due to peritonitis, intra-abdominal abscess, and wound infection, and were directly proportional to the length of time from colonic injury to repair. On the basis of this study, it is concluded that most isolated injuries of the colon can be closed primarily, if antibiotic therapy is begun immediately after injury and continued throughout the operative and postoperative periods.


Respiratory morbidity in rubber workers: I. Prevalence of respiratory symptoms and disease in curing workers. One hundred twenty-one men who were exposed to tire-curing fumes responded to respiratory symptom questionnaires. Results were compared with questionnaires of 189 nonexposed workers who were employed by the same three tire manufacturing plants. The curing workers had a higher prevalence of chronic bronchitis than the controls. Of the curing workers with more than ten years of experience to fumes, 25% met the criteria for the epidemiological diagnosis of chronic obstructive pulmonary disease. Increased respiratory morbidity in the curing workers was related to both intensity and length of exposure to fumes. Because cigarette smoking and other variables cannot explain the difference between the curing and control groups, we attribute the greater prevalence of respiratory morbidity to exposure to curing fumes. These findings warrant further longitudinal studies and reduction of exposure, especially for workers on the manual automobile tire presses, which is the high-exposure group.


Giant pilomatrixoma (Malherbe calcifying epithelioma). The pilomatrixoma (Malherbe calcifying epithelioma) starts as a skin lesion, bearing a superficial resemblance to the common inclusion or sebaceous cysts. One of the largest cysts recorded appeared in a 56-year-old woman as an ulcerated, locally invasive tumor. The cyst demonstrated the typical ghost (shadow) cells, basophilic cells, keratin pearls, and calcifications. The lesion responded to wide excision and skin grafting. The result 17 months later was most satisfactory.


Effects of cyclamate calcium on the immune response in rabbits. To determine the effect of cyclamate calcium on the humoral immune response in rabbits, one group was fed a 3% and another a 5% water solution of cyclamate calcium. A third group served as controls. After 150 days, the animals were tested for their ability to respond immunologically to bovine serum albumin (BSA). Other aspects of immunity investigated were the presence or absence of neoplasia of the urinary bladder, spleen, thymus, and lymph nodes, the number of white and red blood cells, and cyclamate conversion and excretion in the urine. The results indicated that the 5% group had a delayed and suppressed response to BSA. No neoplasia was detected. This group had fewer red cells and excreted increased concentrations of cyclohexylamine in the urine.


Serosal tears following colonoscopy.

Serosal tears following colonoscopy. After colonoscopic perforation, laparotomy was performed in a 28-year-old woman. Seromuscular tears and lacerations were found in an adjacent loop of sigmoid colon that appeared normal through the colonoscope. At laparotomy, the mucosa of that loop was entirely intact. Six weeks later, a laparotomy was again performed, revealing well-healed lacerations with extensive adhesion formation. The incidence of this complication in patients undergoing colonoscopy is unknown.


Endoscopic removal of submucosal colonic lipomas. Although lipomas of the colon are second only to adenomatous polyps in frequency of benign lesions of the large bowel, they occur relatively rarely. These lesions are reported to be symptomatic in 15% to 91% of cases. Endoscopically, the lipoma is soft and pliable and appears globular and covered by pale "normal" tunica mucosa. The treatment of choice is colonoscopy and snare excision because of the potential hazards of bleeding and bowel obstruction and because the diagnosis can be confirmed only by histologic examination.


The posterior triangle in radical neck surgery. We evaluate the importance of cancer spread to the lymphatic system in the posterior triangle. The posterior triangle tissues of 51 radical neck specimens were serially sectioned and studied for metastic involvement. The findings were correlated with the findings in the anterior triangle and the primary tumor. Of the 51 neck operations performed, 25 were elective and 26 were therapeutic for carcinoma of the larynx, pharynx, and oral cavity. Metastasis in the anterior triangles was detected in 88.4% of the therapeutic group and in 24.0% of the elective group. However, no metastasis in the posterior triangel was found in either group, regardless of the site of the tumor. We suggest that the posterior triangle can be totally preserved in radical neck surgery, which may make preservation of the spinal accessory nerve a more likely practice.


Nasal sarcoidosis.

Nasal sarcoidosis. Nasal sarcoidosis may affect nasal skin, mucosa, or bone separately or simulataneously. Its incidence in patients with systemic sarcoid was once thought to be low, but this may be due to lack of proper intranasal examination and awareness of its existence by physicians who are more preoccupied with lung and other visceral involvement. The otolaryngologist should be aware of nasal sarcoidosis because nasal obstruction or drainage secondary to nasal sarcoidosis may be the first and only manifestation of systemic sarcoidosis. The otolaryngologist can diagnose this disease earlier in its course by being aware of its existence.


Goblet cell density in Eustachian tube of children. In 13 clinically normal infants and children between the ages of 9 days and 14 years, the entire mucosa from the Eustachian tube was dissected and stained by the PAS-Alcian blue whole-mount method, and the density of goblet cells was determined in 360 counting fields. This disclosed an extreme dispersion of median density in the various parts, due to a physiological increase through childhood, an increase in the osseous or cartilaginous part, and in the entire Eustachian tube due to pathologic actions such as tubal occlusion, recurrent or protracted catarrhal conditions, regurgitations, and duodenal intubation. After the pathologic stimulation has ceased, the density falls, presumably to the limit normal for the age concerned.


Pathologic findings in gouty cricoarytenoid arthritis. The clinical manifestations of cricarytenoid joint gouty arthritis have been previously reported. They include hoarseness, dysphagia, and dysphonia. Exacerbation of gouty laryngeal arthritis can accompany multiple joint involvement or appear as a single joint manifestation. The development of laryngeal symptoms in the patient with arthritix calls for prompt indirect laryngoscopy. The phonatory and sphincteric functions of the larynx are severely altered by limited cricoarytenoid joint fixations.


Frequency responses of office electronystagmography machines. The high and low frequency characteristics of clinically used electronystagmography (ENG) machines were evaluated using a "dummy patient" calibration source. About one half of the machines yielded tracings that were either seriously divergent from specifications or that otherwise inaccurately reproduced the calibration wave form. Some of these differences do affect the accuracy and quality of clinical recordings.


Sensorineural deafness due to osteitis fibrosa. A 91-year-old woman with deafness died from renal failure. Autopsy revealed osteitis fibrosa cystica generalisata, chronic myeloid leukemia, renal atrophy, and hyperplastic parathyroid glands. The temporal bones showed senile osteoporosis, osteitis fibrosa, and chronic myeloid leukemia. The inner ears showed extensive degeneration of cochlear sensorineural elements. The perilymph showed a general increased staining reaction with hematoxylin-eosin that was most evident in localized areas, where marrow spaces of osteitis fibrosa communicated directly with perilymph. It appears that the active diseased marrow exerted a toxic effect on the sensorineural elements of the cochlea by diffusion through the perilymph.


Hemangiopericytoma of the maxilla.

Hemangiopericytoma of the maxilla. Hemangiopericytoma is a vascular tumor that typically occurs in the soft tissues of the extremities and trunk, and only rarely occurs in the paranasal sinuses and nasal cavity. We report a case of hemangiopericytoma of the maxilla and review the pertinent literature. Based on a propensity for local recurrence and occasional metastasis, a radical excision was performed.


Stellate ganglion blocks for idiopathic sensorineural hearing loss. Fifty-six patients, treated with a series of anesthetizing blocks of the stellate ganglion for idiopathic sudden sensorineural loss, were compared with 20 patients of similar diagnosis who were treated by other means as to amount of pure-tone gain, speech discrimination improvement, nature of symptoms, and delay in start of surgery. Seventy percent of the stellate-ganglion-block-treated patients achieved substantial hearing improvement. Only 15% to 20% of the non-stellate-ganglion-block-treated patients achieved substantial hearing improvement in discrimination or pure-tone levels. The delay time from onset of symptoms to start of stellate block therapy appears to be important. The type of tinnitus, presence or absence of vertigo, and fullness in the ear may be useful prognostic signs.


Cryosurgery of supraglottic cavernous hemangioma. Cryosurgery is gaining more and more importance as a therapeutic modality within the field of head and neck surgery. It has been used effectively in the treatment of cavernous hemangiomas of the skin and oral cavity. Supraglottic vanernous hemangiomas present a challenge in management when surgical intervention is indicated. The results of cryosurgery in the treatment of such a lesion are reported.


Percutaneous embolization to control epistaxis in Rendu-Osler-Weber disease. Recurrent epistaxis is the most common manifestation of hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease), a disorder characterized by widely scattered visceral, dermal, and mucosal vascular lesions. Emergency measures applied locally may control acute hemorrhage, but seldom result in long-term benefit. Recently, we have had the opportunity of performing bilateral carotid angiographic examination on a patient with hereditary hemorrhagic telangiectasia who was suffereing from severe intractable epistaxis. At the time of angiographic examination, embolization of both internal maxillary arteries was accomplished, and control of the epistaxis was achieved. In the patient with severe epistaxis that is unresponsive to local measures, percutaneous embolization offers substantial advantages over surgical intervention.


Action of growth hormone in vitro on the net uptake and incorporation in protein of amino acids in muscle from intact rabbits given protein-deficient diets. 1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hromone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets. 2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulate amino acid incorporation into protein, although this response was less in LP animals than in control animals. 3. In muscle of PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals. 4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis. 5. It is proprosed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.


The diets of preschool children in Newcastle upon Tyne, 1968-71. 1. Ninety-one families containing 140 children under 4 years of age at enrolment were studied. At 1-monthly intervals, the children were weighed and measured and qualitative information about feeding habits was obtained. Weighed dietary surveys for periods of 5 d were made at approximately 8 months, 3 years, and 5 years of age; there were forty-six failures in 260 surveys attempted. 2. At the four specified ages, mean energy intakes were 3-75, 5-03, 5-82 and 6-75 MJ (896, 1203, 1392 and 1613 kcal)/d respectively. At 8 months, milk products provided on average, 43% of the total energy intake, and commerical baby foods provided 17%. These values decreased to 21 and 2% respectively at 20 months and there was little further change therafter. 3. Average intake of energy and of most nutrients met recommended intakes (Department of Health and Social Security, 1969). Iron intakes were marginal, and vitamin D intakes were low. 4. The energy intake of boys was significantly higher than that of the girls at 3 years of age, but the boys were not significantly heavier. The energy intake of children from "manual-worker" families was higher than that from "non-manual" families. Similarly, the energy intake of children from larger families was higher than that of children from smaller families. 5. Energy intakes were correlated with body-weights and with rates of gain in weight. Irrespective of body-weight, "big eaters" at 20 months tended to be "big eaters" at 3 years also.


The effect of molybdenum on the conversion of sulphate to sulphide and microbial-protein-sulphur in the rumen of sheep. 1. [35S]sulphate was used to measure the apparent turnover of sulphate, sulphide and microbial-protein-S in the rumen contents of four sheep that were intraruminally infused with 10 g sodium sulphate/d alone, or together with 126 mg sodium molybdate (50 mg molybdenum). 2. Infusion of molybdate increased the concentration of sulphate in rumen fluid from 2.2 to 7.2 mug S/ml and decreased the rate of reduction of sulphate to sulphide by 50%. Although the rate of sulphide production was slower, the concentration of sulphide in the rumen is suggested to explain these changes. 3. In animals that were not infused with molybdate, only one-third of the S (3.0 g/d) that passed through the sulphate pool in rumen fluid was converted to sulphide, decreasing to one-sixth when molybdate was infused. 4. The turnover of S amino acids in microbial protein was not significantly affected by molybdate. Only 52-57% of the S amino acid content of microbial protein was synthesized de novo by way of the sulphide pool.


Biotin deficiency and fatty liver and kidney syndrome in chicks given purified diets containing different fat and protein levels. 1. The occurence of biotin deficiency and fatty liver and kidney syndrome (FLKS) in chicks was studied using a 2x2x2x2 factorial-design experiment in which the variables were dietary biotin, fat and protein, and starvation. 2. The severity of biotin deficiency, using growth retardation and severity of dermal lesions as criteria, was least when  the low-biotin diet also contained low levels of fat and protein. Addition of fat or protein increased the severity of the deficiency. Tissue fatty acid composition was affected by biotin deficiency only in those birds given the low-protein, low-fat diet. The main change was an increase in the ratio, 16:1 fatty acids :18:0 fatty acids. Plasma glucose and free fatty acid levels in non-fasted birds were unaffected by the dietary variables. 3. Mortality from FLKS with the diet containing low biotin, fat and protein levels was 52% at 28d, but was reduced or eliminated when the dietary level of any of these ingredients was increased. 4. Starvation considerably increased the incidnece of FLKS in the period immediately after fasting, and also affected plasma glucose and free fatty acid concentrations. Liver fatty acid composition, indicated an increase in the proportion of 18:0 at the expense of 16:1 and concentrations increased in proportion, at the expense of 18:0. 5. The relationship between biotin deficiency and FLKS, and a possible mechanism for the induction of FLKS by starvation are discussed.


Further studies of the dynamics of nitrogen metabolism in sheep. 1. A study of ammonia and urea metabolism in sheep was made using isotope dilution techniques with (15NH4)2SO4,[15N]urea and [14C]urea in order to determine quantitatively the movements of urea-N and NH3-N throughout the body of normal, feeding sheep. 2. Single injections of 15N-labelled compounds were made into the rumen fluid NH3, caecal fluid NH3 and the blood urea pools, in order to estimate the rates of flux through, and the transfer of N between, these and other nitrogenous pools in the body. 51CrEDTA was injected into the rumen and caecum with (15NH4)2SO4 to allow estimation of fluid volumes and to provide an indication of mixing, and of times of transit of isotopes between different sampling sites in the digestive tract. 3. The sheep ate approximately 22 g lucerne chaff/h and the mean dietary N intake was 16-3 g/d. 4. The rate of flux of NH3 through the rumen NH3 pool was 15-0 g/d (i.e. 90% of the dietary N ingested; however, this amount also included N from plasma urea (1-1 g/d) and other endogenous sources including NH3 derived from caecal NH3 (0-4 g/d). 5. Only 40% of the N in isolated rumen bacteria was derived from NH3, indicating that a considerable proportion of their N requirements were obtained from compounds other than NH3 (e.g. peptides and amino acids). 6. There was evidence of recycling of N between nitrogenous pools in the rumen, probably through rumen NH3 leads to microbial N leads to NH3. 7. It was estimated that 5-3 g blood urea-N/d entered the digestive tract; 20% of this urea was degraded in the rumen, 25% in the caecum and the remainder was apparently degraded elsewhere; there was evidence of urea degradation in the large intestine posterior to the caecum and it is suggested that urea degradation and absorption of the resultant NH3 may occur in the ileum. 8. Of the 4-8 g N/d entering the caecal NH3 pool, 4-2 g N/d left and did not return and the difference (0-6 g N/d) was recycled, possibly through caecal NH3 leads to microbial N leads to NH3. 9. A large proportion of the NH3 entering the caecal NH3 pool (70% or 3-2 g N/d) was apparently derived from degradation of nitrogenous products, other than urea, including rumen microbial N (1-0 g N/d) passing undigested from the small intestine. 10. Less than half the NH3-N of caecal origin entering the rumen passed through the blood urea pool; the remainder was apparently transported as other nitrogenous compounds in the blood or body fluids. 11. The results of the three experiments were combined in a general three-pool, open-compartment model which formally recognizes an unlimited number of other unspecified, interconnected pools together comprising the whole-animal system. Rates of flux through, and transfer of N between these and other nitrogenous pools in the body were calculated by solving this model and the information derived has been applied to whole-animal models with a view to subsequently using these models in computer simulation studies.


Simulation of the dynamics of nitrogen metabolism in sheep. 1. The results of isotope tracer studies of the dynamics of nitrogen metabolism in mature sheep were used to construct a seven-pool mathematical model. 2. The model was extended to a nine-pool model, which incorporates lags describing the time taken for the passage of digesta through the gut of sheep. 3. Simulation studies using these models satisfactorily predicted results of independent experiments. 4. The dynamics of N metabolism in sheep appear to be best approximately by first-order kinetics; that is, many of the important N transport processes are substantially linear or concentration-dependent.


Resistance to ketosis during prolonged fasting by rats fed on a diet containing undecanoic acid, an odd-carbon-number fatty acid. 1. Sixty-four male rats were fed on a nutritionally complete diet containing 30% of the dietary energy as fat. For thirty-two rats (control) the fat source was maize oil; for the remaining thirty-two rats (experimental) the fat source was triundecanoin-maize oil (7:3, w/w). 2. After 6 weeks, groups of control and experimental rats were fasted and killed on days 0, 1, 2, and 4 of the fasting period. In the experimental group, adipose-tissue fatty acids contained, on average, 246 mmol undecanoic acid/mol total fatty acids. In contrast, the adipose tissue of the control group did not contain odd-carbon-number fatty acids. 3. Plasma glucose levels were significantly higher for all fasted experimental groups and blood ketone levels were significantly lower for these groups. 4. Thus, during prolonged starvation, animals which accumulated odd-C-number fatty acids resisted the development of ketosis. It appeared that odd-C-number fatty acids mobilized from fat depots during fasting may provide their terminal three-C-residues for gluconeogenesis rather than for acetyl-CoA production, thereby allowing for better maintenance of blood glucose and insulin levels than in control animals. 5. It is concluded that the lower acetyl-CoA production and higher blood insulin levels reduce ketogenesis.


The efficacy of protein supplementation in overcoming urea toxicity in sheep. 1. In the first experiment sheep taken from pasture were given a low-protein diet for six weeks in individual pens. Then, for 1 week, groups were given a supplement of lucerne chaff, safflower meal or lucerne chaff plus safflower meal. In the second experiment eighteen sheep maintained on lucerne chaff rather than pasture were then depleted of protein to a greater extent by feeding on a restricted low-protein diet. Six of the sheep received a supplement of molasses throughout the period of protein depletion while six of the sheep on the basal ration received a supplement of safflower meal after 6 weeks on the low-protein diet. 2. The urea tolerance of the sheep, is indicated by blood ammonia levels after oral dosing with aqueous solutions of urea, was determined after the period of supplementation. "Arginine synthetase" activity (combined activities of argininosuccinate synthetase (EC 6.3.4.5) and argininosuccinate lyase (EC 4.3.2.1) was determined in liver samples obtained by biopsy at various intervals during the experiment. 3. Supplementation for 7 d with 73 g crude protein (nitrogen X 6-25)/d increased the tolerance to urea as indicated by reduced blood NH3 levels, and also increased "arginine synthetase" activity. 4. Giving supplements of molasses delayed the onset of urea toxicity but not the extent of toxicity. 5. It is suggested that short-term feeding of protein concentrates to sheep before giving urea supplements can increase their tolerance to urea.


Lack of effect on blood lipid and calcium concentrations of young men on changing from white to wholemeal bread. 1. When nineteen "free-living" male students, who normally ate 231 (SEM 14) g white bread/d changed to wholemeal bread for a 19-week period, there was no significant change in body-weight, plasma cholesterol or plasma triglyceride levels. These values, as well as plasma concentrations of calcium, phosphate, urate and haemoglobin, remained essentially the same as those for a control group. 2. Increasing the wheat-fibre intake by eating wholemeal bread is not an effective method for reducing blood lipids levels, at least in healthy young men with a moderate bread intake.


Protein absorption and ammonia production: the effects of dietary protein and removal of the colon. 1. The effect of increasing dietary protein content on the amount of faecal nitrogen was measured in six normal subjects and five subjects without functioning colons (three with ileostomy and two with ileo-rectal anastomosis). 2. There was a significant inontent in the subjects without functioning colons. 3. In normal subjects with intact colons, faceal N content was found to be lower than that in subjects without colons, and furthermore there was no significant variation with diet. 4. The source of the increase in faecal N with increased dietary protein content in subjects without functioning colons is discussed and the significance of these findings in relation to the efficiency of protein absorption is considered.


The effects of low-dose gamma-irradiation on the wholesomeness of mangoes (Mangifera indica) as determined by short-term feeding studies using rats. 1. A control diet and diets containing 150 g non-irradiated or 150 g irradiated mangopulp/kg were given to female rats from day 15 of the gestation period until weaning in trials 1 and 2, and from 40 d before mating until 28 d post weaning in trial 3. 2. Food intake and dry-matter digestibility were similar with all diets. 3. There were no significant differences between animals given the different dietary regimens in the daily body-weight changes of weanling males, pups, nursing females or females during the immediate postlactation period. 4. No differences in haematological or blood chemistry values were found which could be attributed to the ingestion of irradiated mangoes. There was no evidence for the presence of any toxic substances in the irradiated-mango-pulp diet. 5. Gross pathological observations revealed no aberrations which could be related to the ingestion of irradiated mangoes. 6. It may be concluded that the wholesomeness of mangoes was not affected by gamma-irradiation at a dose of 75 krd.


The effect of feeding frequency on the growth on composition of individual organs in the rat. 1. The effect of consuming the same total amount of food in either one large meal or several small meals per d was studied using weanling male rats. 2. The increase in total body-weight was the same in both instances, but the weights of the liver, kidneys, femur, small intestine and stomach were greater, and those of the spleen and residual carcass were smaller, in meal-eating rats than in continuously fed control animals. These differences persisted into the adult state. 3. No differences in gross chemical compositions were found between the corresponding organs of the two groups of rats, and the differences in weight appeared to be the result of changes in the general growth rate of individual organs. 4. The hypertrophy of the kidneys in meal-eaters was due to an increase in mean cell size, but the increased weight of the liver and reduced weight of the spleen appeared to be largely the result of changes in the number of cells present.


Percent satellite DNA as a function of tissue and age of mice. A selective loss of satellite DNA was found to occur to different extents as a function of tissue and age of mice using several common DNA extraction and purification procedures. This result emphasizes a serious problem that may be encountered in comparative studies of DNA structure and composition if selective loss of specific DNA sequences occurs. We have developed a DNA extraction and purification procedure that is simple and reliable and gives a high percent DNA yield, which substantially reduces the selective loss of heterochromatin DNA sequences. The method features a centrifugation step of a proteolytic digest of chromatin in 2.4 M CsCl. Percent DNA yield of 82-98% are routinely obtained with no apparent loss of satellite DNA sequences from different tissues or ages of mice. Utilizing this method, percent satellite DNA was found to remain essentially constant at 11 +/- 1% for spleen, kidney, and brain tissues obtained from mice of 10-780 days of age. However, for liver, percent satellite DNA remained at about 7-8% from 10 to 300 days of age and then increased to about 12-13% from 300 to 600 days of age. During this latter time interval (300-600 days), an increase of DNA per nucleus of about 3-fold occurred, due to the formation of tetra- and octaploid cell types. A steady loss in the total number of nuclei per gram of liver as a function of age was also found. These two opposing effects resulted in a nearly constant amount of DNA per gram and per organ for liver throughout the lifespan of the mouse.


Ribosomal cistrons in higher plant cells. I. A definitive scheme for the maturation pathway of the primary transcriptional product of ribosomal cistrons in Acer pseudoplatanus L. cells. 1. Four precursor ribosomal RNAs have been previously characterized in cultured sycamore cells (Acer pseudoplatanus L.). The present paper reports a study of the two smallest ones. 2. (Me-3H)-labelling of the precursor and mature rRNAs has been submitted to kinetic analysis. From pulse-chase experiments it is concluded that the 27S and 20S precursor rRNAs behave like intermediate molecules in the maturation of the 42S and 36S precursor rRNAs into the 26S and 17S components. They are direct precursors to the cytoplasmic and mature rRNAs. 3. Base-composition analyses have been performed on carefully purified molecules. They show that the 27S and 20S precursor rRNAs arise from a single cleavage of the 36S precursor rRNA. In addition, they strongly suggest that the 27S and 20S precursor rRNAs can be taken as specific precursors to the 26S and 17S rRNAs, respectively. These results are reinforced by DNA - RNA hybridization experiments, the measured values being in good agreement with the theoretical ones expected from a specific relationship between the four smallest molecules. Base-compositions of the conserved and non-conserved nucleotide sequences of the primary transcriptional product have been estimated or calculated. 4. On the basis of the present results and those previously reported, a scheme for the biosynthesis of ribosomal RNA in sycamore cells is proposed.


Ribosomal cistrons in higher plant cells. II. Sequence homology between the two mature rRNAs of sycamore cells and intracistronic reiteration. A DNA - rRNA hybridization study. 1. Uniformly labelled rRNA of sycamore cells has been annealed with homologous DNA. The fractions of DNA complementary to the 17S, or 26S, or 17S + 26S rRNAs are found to be 0.19%, 0.15% and 0.23%. They are not in the ratio of the molecular weight values (0.8, 1.2 and 2 - 10(6), respectively for the 17S, 26S and 17S + 26S rRNAs). This result is compatible with the large hybridization competition observed between the two rRNAs (53 and 72%) and with the shift-down of saturation curves when DNA is presaturated with unlabelled rRNA before the incubation with the other labelled rRNA. 2. Under the selected experimental procedure, the DNA - rRNA hybrids formed appear to be specific. Since there is an equal number of structural genes for the 17S and 26S rRNAs, these results mean the occurrence of a great sequence homology, strictly restricted to the two rRNAs. Homologous and specific sequences have been estimated to 0.1 and 0.7, or 0.85 and 0.35 million daltons, respectively in the 17S or 26S structural genes. 3. From the calculated lengths of homologous sequences, an intracistronic reiteration of some ribosomal sequences can be deduced. This internal reiteration is directly evidenced by the complex pattern of DNA - rRNA annealing curves. As demonstrated by base-composition analysis, the internal reiteration is heterogeneous and concerns both the homologous and specific sequences. In addition, the DNA saturation values allow the calculation of 4000 copies for the ribosomal cistron in the whole sycamore genome.


RNA synthesis in isolated HeLa cell nuclei. RNA synthesis has been studied in isolated nuclei of HeLa cells. The incubation medium has been optimized for RNA synthesis and the requirements for the presence of specific components previously used by other investigators has been examined. Nuclei isolated by centrifugation through 2 M sucrose synthesize RNA linearly for at least 1 h only at low temperature (25 degrees C). Low molecular weight RNA is found in the supernatant fraction after incubation; this RNA accounts for about 10% of the RNA synthesized. The RNA which remains within nuclei is of high molecular weight and processing of this RNA into molecules of the size of cytoplasmic mRNA does not seem to occur in isolated nuclei. We have studied the effect of an inhibitor of protein-nucleic acid interaction - aurintricarboxylic acid - on RNA synthesis by isolated nuclei. At concentrations below 0.1 mM, this drug does not inhibit RNA synthesis effectively, whereas at concentrations above 0.1 mM it inhibits RNA synthesis by about 80%. In view of the proposed mechanism of action of aurintricarboxylic acid, we suggest that completion of nucleotide chains initiated before nuclei isolation accounts for 20% of the RNA synthesized in our system by isolated nuclei, whereas nucleotide chains initiated during the in vitro incubation account for 80% of the RNA synthesized.


Influence of temperature and magnesium ions on the secondary and tertiary structures of tRNAPhe and 23 S RNA - infrared investigations. Band splitting and/or bands shifting in opposite directions due to coupling of vibrations of neighboring groups observed in the infrared spectra of tRNAPhe and 23 S RNA give information on the secondary structure. The base pairing, dependent on temperature, is investigated, discussing coupling effects with the base residues' vibrations in the region 1700-1500 cm-1. The secondary structure of the backbone is studied, discussing coupling effects with vibrations in the region 1300-1000 cm-1. The 2'OH groups are cross-linked with the O atoms of the neighboring ribose residues via hydrogen bonds. Probably the greater than PO-2 groups are turned inward at the backbone, i.e. towards the base residues. The base pairs as well as the secondary structure of the backbone melt with increasing temperature and with dialysis against distilled water. The comparison of the Mg2+ and the K+ salts of the tRNAPhe shows that the changes of base pairing due to Mg2+ are small. At the backbone, however, Mg2+ favor somewhat more the discussed secondary structure than K+ does. All Mg2+ effects on secondary structure are, however, too small to explain the considerable increase in melting temperature due to Mg2+. Thus it is supposed that the rise in the melting temperature due to Mg2+ is not caused by a change in secondary but in the tertiary structure of tRNAPhe. Furthermore, the influence of Mg2+ on the secondary structure of 23 S RNA is studied. The following results are obtained: (1) The double helical regions become more compact and probably increase due to the influence of Mg2+. (2) At the backbone, Mg2+ induces strong hydrogen bonding between the 2'OH groups and the ether O atoms of neighboring ribose residues. Probably they turn the greater than PO-2 groups toward the base residues, i.e., inward at the backbone. Schulte, Morrison and Garrett found that a critical level of Mg2+ is required for binding certain proteins to rRNA (Biochemistry (1974) 13, 1032). Thus the observed conformation is probably necessary for binding these proteins.


Inactive form of edeine in the edeine-producing Bacillus brevis Vm 4 cells. 1. Exogenous edeine inhibits the synthesis of DNA and protein, but not that of RNA, in extracts of edeine-producing Bacillus brevis Vm 4 cells. This is analogous to the effect of edeine on extracts obtained from edeine-sensitive cells. 2. Producer cells, in contrast to sensitive ones, are not permeable to exogenous edeine. DNA synthesis in producer cells rendered permeable by toluene treatment becomes sensitive to edeine. 3. No free edeine could be detected in post-log producer cells during maximal synthesis of edeine. Nascent edeine exists in the cell in a biologically inactive form, bound to a fast-sedimenting fraction. Edeine B, identical to the antibiotic present in the medium, is released from this fraction by mild treatment with alkali.


Phosphorylation of ribosome-associated proteins during the mammalian cell cycle. Unique phosphorylation of a specific protein during mitosis. Chinese hamster ovary cells in monolayer culture were incubated with [32P] phosphate. Ribosome-associated proteins, including both structural proteins and those tightly bound to washed, centrifuged ribosomes, were isolated and separated by electrophoresis on sodium dodecyl sulfate-polyacrylamide gels. The electrophoretic pattern showed five major regions or peaks of 32P radioactivity which represented phosphorylated ribosome-associated proteins with molecular weights of 17 500, 23 000, 30 000, 38 000, and 57 000. When asynchronous cells were pulse-labeled with [32P] phosphate, the predominant peak of 32P radioactivity was associated with the protein of 38 000 daltons. Similar results were obtained with cells synchronized in the G1, S, or G2 phase of the mammalian cell cycle. Conversely, proteins isolated from the ribosomes of mitotic cells, collected and labeled with [32P] phosphate in the presence of colcemid, showed a new and predominant peak of 32P radioactivity migrating with a protein of 45 000 daltons. When cells labeled in mitosis were allowed to progress into G1 phase, this peak of 32P radioactivity rapidly disappeared from the electrophoretic pattern. These results suggest that a specific protein associated with the ribosomes was phosphorylated uniquely during the mitotic phase of the cell cycle.


The synthesis of connective tissue protein in smooth muscle cells. The synthesis of elastin by smooth muscle cells was clearly demonstrated by amino acid analyses and the presence of lysine-derived crosslinks. The values obtained were compatible with those found in amorphous elastin isolated from rabbit aortic tissue. Collagen synthesis by these same cells was monitored by the appearance of [14C] hydroxyproline when the cells were grown in the presence of [14C] proline. When the cells were pulsed with [14C] lysine, one could detect [14C] hydroxylysine and [14C] glucosylgalactosylhydroxylysine. Further evidence for the synthesis of elastin and collagen was the finding of radiolabelled epsilon-hydroxynorleucine and the reduced aldol condensate of two residues of allysine after reduction of [14C] lysine pulsed cells with NaBH4.


Proton magnetic relaxation studies of mixed phosphatidylcholine/fatty acid and mixed phosphatidylcholine bimolecular bilayers. High resolution proton spin-lattice relaxation times (T1), spin-spin relaxation times (T2) and resonance linewidths were measured above the gel-to-liquid crystal transition temperature (Tm), in phosphatidylcholine bilayers possessing various degrees of intramolecular motional anisotrophy at the level of various alkyl chain proton groups. The experiments were designed to test the hypothesis that coupled trans-gauche isomerizations along the chains can be responsible for the anisotropic motion of phosphatidylcholine proton groups in bilayer membranes (Horwitz, A.F., Horsley, W.J. and Klein, M.O. (1972) Proc. Natl. Acad. Sci. U.S. 69,500). Systematic series of structural perturbations of the bilayer were achieved in mixed phosphatidylcholine/fatty acid and in mixed phosphatidylcholine bilayers where the degree of motional anisotrophy of the chains' proton groups was gradually reduced by progressively increasing the chain length disparity of the two components. The systematic T1 and T2 variations observed were interterpreted on the basis of the Woessner's treatment for computing the relaxation times of a spin pair reorienting randomly about an axis which, in turn, tumbles randomly (Woessner, D.E. (1962) J. Chem. Phys. 36, 1). The results confirmed in a qualitative sense the original hypothesis made by Horwitz et al. The time-averaged structural interpretations suggested by the mangetic relaxation studies are in agreement with low-angle X-ray diffraction results obtained below Tm. In addition, the T1 values evaluated at various temperatures in dipalmitoyl phosphatidylcholine vesicles incorporated with either 2H-labeled or unlabeled palmitic acid chains indicated that the average intermolecular contribution to the spin-lattice relaxation rate of the proton groups of the phosphatidylcholine chains appears comparable to the intramolecular term at temperatures moderately higher than Tm, but becomes less and less important as the temperature is further increased above the thermal transition.


Inhibition of protein kinase activity and amino acid and alpha-methyl-D-glucoside transport by diamide. Dizene dicarboxylic acid bis-(N,N-dimethylamide), commonly called diamide, is known to oxidize stoichiometrically intracellular pools of reduced glutathione and inhibit the accumulation of sugars and amino acids by rat kidney slices. Incubation of rat cortical slices in diamide also leads to a significant decrease in the level of endogenous protein kinase activity. The inhibition of sugar and amino acid transport and protein kinase activity by diamide is partially reversible by the addition of exogenous glutathione or other thiols. A comparison of protein kinase activity with amino acid and sugar transport at various concentrations of diamide indicates that there is a high degree of correlation between these two processes.


Temperature dependence of uridine transport in quiescent and serum-stimulated 3T3 cells. (1) The kinetics of uptake of uridine into 3T3 cells have been measured as a function of concentration in the temperature range 5-37 degrees C, for both quiescent and serum-stimulated cells. (2) The maximun velocity of uridine uptake is increased some ten-fold by adding serum, but the hald-saturation concentration is not systematically affected in this temperature range. (3) A detailed study of the temperature dependence of the maximum velocity of transport in the range 4-43 degrees C shows that the activation energy of uridine transport is not increased following serum activation. (4) The data suggest that any change in membrane fluidity that might occur as a result of serum activation does not in itself lead to a more rapid rate of turn over of the individual uridine carriers. It would appear, rather, that there is an increase in the number of functional uridine carriers.


Structural and dynamical studies of mixed chlorophyll/phosphatidylcholine bilayers via x-ray diffraction, absorption polarization spectroscopy and nuclear magnetic resonance. The structure and dynamics of phosphatidylcholine bilayers containing chlorophyll were studied by X-ray diffraction and absorption polarization spectroscopy in the form of hydrated orientated multilayers below the thermal phase transition of the lipid chains and by nuclear magnetic resonance in the form of single-wall vesicles above the thermal transition. Our results show that (a) chlorophyll is incorporated into the phosphatidylcholine bilayers with its porphyrin ring located anisotropically in the polar headgroup layer of the membrane and with its phytol chain penetrating in a relatively extended form between the phosphatidylcholine fatty acid chains in the hydrocarbon core of the mixed bilayer membrane and (b) the intramolecular anisotropic rotational dynamics of the host phosphatidylcholine molecules are significantly perturbed upon chlorophyll incorporation into the bilayer at all levels of the phosphatidylcholine structure. These dynamics for the host phosphatidylcholine fatty acids chains are qualitatively different from that of the incorporated chlorophyll phytol chains on a 10(-9)-10(-10)s time scale in the ideally mixed two-component bilayer.


Alpha-Glutamyl-beta-naphthylamide hydrolase of rabbit small intestine. Localization in the brush border and separation from other brush border peptidases. About 70% of the total mucosal enzymatic activity hydrolyzing beta-L-glutamyl-beta-naphthylamide in the rabbit small intestine is present in the brush border; the specific activity in this subcellular fraction is 7 times higher than that of the homogenate. Similar results are obtained for L-leucyl beta-naphthylamide hydrolase. The enzyme activity is efficiently solubilized by papain digestion and is clearly separated from L-leucyl-beta-naphthylamide hydrolase by chromatography on concanavalin A-Sepharose. It probably represents a digestive peptidase, different from the other known peptide hydrolases of the digestive surface of the small intestine.


Distribution of free sulfhydryl and disulfide groups among platelet membrane proteins. Reactive sulfhydryl and disulfide groups were identified in platelet membrane proteins resolved by sodium dodecyl sulfate-polycrylamide gel electrophoresis. Platelet membranes treated with N-ethyl(1-14C)maleimide, phenyl(203Hg)mercuric acetate and p-chloro(203Hg)mercuribenzoate showed similar patterns of distribution of sulfhydryl groups among the sodium dodecyl sulfate-solubilized membrane proteins. Four major and two minor polypeptides ranging in molecular weight from greater than 200 000 to 20 000 were found to have reactive SH groups. Reduction of membrane proteins by sulfite coupled with subsequent mercaptide formation of the resultant monothiols led to the identification of four polypeptides with disulfide bonds. Reaction of platelet membranes with 14C-labeled 5,5'-dithio-bis(2-nitrobenzoic acid) resulted changes in the distribution profile of the solubilized membrane proteins suggestive of a polymerization process dependent upon, 5,5'-dithio-bis(2-nitrobenzoic acid)-induced intermolecular disulfide interchange.


Stabilometry and some aspects of its applications--a review. This paper reviews some of the available literature on a comparatively new and rapidly developing method for the study of man's stability of stance, "stabilometry", and some aspects of its application. The principle of this method consists in translating the mechanical oscillations of man's physiological gravicentre into electrical signals, their amplification, recording, and analysis. The method may be used to carry out research in various specialised disciplines including clinical medicine, otorhinolaryngology, industrial and sports physiology. Additional application areas of stabilometry are aerospace medicine and the manufacture of artificial limbs. The purpose of this review is to direct the attention of investigators, physicians, and specialists toward the future development of this promising method.


Transmembrane pressure stabiliser for haemodialysis. A simple, new device for setting and maintaining the pressure for ultrafiltration during renal dialysis with a coil dialyser is described. Experimental evidence suggests that it has distinct advantages over the conventional method and in clinical use in more than 1,000 cases no difficulties have been encountered.


A digital technique for linearising the output of a turbine anemometer. A technique is described by which it is possible, using digital integrated circuits, to linearise the output of transducers which produce their output in serial digital form. The linearisation technique is used to improve the performance of an anemometer used in the measurement of pulmonary function. The new technique makes possible accurate paediatric measurements using transducers previously intended for adults.


Electronic tooth stimulator for pain research. It is not possible to measure pain but it is possible to measure the stimulus that causes it. Electrical stimuli are probably the most suitable since they can be readily produced and accurately measured. Applying stimuli to the teeth of human subjects is convenient and does not cause damage. This paper describes a tooth stimulator which is considered to be an advance on other available equipment, being easier to use and more accurate, as well as reassuring for the human patient or experimental subject.


Mode of action of a surgical electronic lithoclast--high speed pressure, cinematographic and schlieren recordings following an ultrashort underwater electronic discharge. In order to investigate the mode of action of the electrical discharges from a surgical electronic lithoclast in shattering bladder stones high speed pressure-time recordings were made. The results indicated effects similar to those following an underwater detonation of high explosive. Subsequent high speed photographic analysis confirmed this. Calculations based on the results suggested that the shock waves and pressure pulses generated were of a potentially hazardous magnitude and that gas-containing bowel close to the bladder might be at particular risk as well as solid tissue as the bladder wall. Photographic data also suggested that danger might be incurred by the use of similar devices in a small enclosed space such as the ureter or renal pelvis.


Membrane viscoelasticity.

Membrane viscoelasticity. In this paper, we develop a theory for viscoelastic behavior of large membrane deformations and apply the analysis to the relaxation of projections produced by small micropipette aspiration of red cell discocytes. We show that this relaxation is dominated by the membrane viscosity and that the cytoplasmic and extracellular fluid flow have negligible influence on the relaxation time and can be neglected. From preliminary data, we estimate the total membrane "viscosity" when the membrane material behaves in an elastic solid manner. The total membrane viscosity is calculated to be 10(-3) dyn-s/cm, which is a surface viscosity that is about three orders of magnitude greater than the surface viscosity of lipid membrane components (as determined by "fluidity" measurements). It is apparent that the lipid bilayer contributes little to the fluid dynamic behavior of the whole plasma membrane and that a structural matrix dominates the viscous dissipation. However, we show that viscous flow in the membrane is not responsible for the temporal dependence of the isotropic membrane tension required to produce lysis and that the previous estimates of Rand, Katchalsky, et al., for "viscosity" are six to eight orders of magnitude too large.


Membrane viscoplastic flow.

Membrane viscoplastic flow. In this paper, a theory of viscoplasticity formulated by Prager and Hohenemser is developed for a two-dimensional membrane surface and applied to the analysis of the flow of "microtethers" pulled from red blood cells attached to glass substrates. The viscoplastic flow involves two intrinsic material constants: yield shear and surface viscosity. The intrinsic viscosity for plastic flow of membrane is calculated to be 1 X 10(-2) dyn-s/cm from microtether flow experiments, three orders of magnitude greater than surface viscosities of lipid membrane components. The fluid dissipation is dominated by the flow of a structural matrix which has exceeded its yield shear. The yield shear is the maximum shear resultant that the membrane can sustain before it begins to deform irreversibly. The yield shear is found to be in the range 2-8 X 10(-2) dyn/cm, two or three orders of magnitude smaller than the isotropic tension required to lyse red cells.


A Fourier method for the analysis of exponential decay curves. A method based on the Fourier convolution theorem is developed for the analysis of data composed of random noise, plus an unknown constant "base line," plus a sum of (or an integral over a continuous spectrum of) exponential decay functions. The Fourier method's usual serious practical limitation of needing high accuracy data over a very wide range is eliminated by the introduction of convergence parameters and a Gaussian taper window. A computer program is described for the analysis of discrete spectra, where the data involves only a sum of exponentials. The program is completely automatic in that the only necessary inputs are the raw data (not necessarily in equal intervals of time); no potentially biased initial guesses concerning either the number or the values of the components are needed. The outputs include the number of components, the amplitudes and time constants together with their estimated errors, and a spectral plot of the solution. The limiting resolving power of the method is studied by analyzing a wide range of simulated two-, three-, and four-component data. The results seem to indicate that the method is applicable over a considerably wider range of conditions than nonlinear least squares or the method of moments.


Continuum reaction field calculation of dielectric constant and vapor pressures for water and carbon disulfide. Continuum reaction field theory is applied to calculations of dielectric constant, contribution of intermolecular interactions to the free energy of a liquid, and heat of vaporization. Introduction of repulsive interactions and the use of one adjustable parameter, the free volume, enables prediction of vapor pressures. The calculations are illustrated for a simple nonpolar liquid, carbon disulfide, and for liquid water. It is shown that when Onsager's equation is rearranged to a quadratic equation, and a recently found value of the polarizability is employed, its solutions for liquid water yield good agreement with experimental values throughout the whole temperature range. The decrease of the dielectric constant with temperature is essentially linear with the inverse of absolute temperature, but there is additional significant decrease due to the decrease of density with temperature. The relatively high value of the heat of vaporization of liquid water is expressed in terms of large dipolar interaction of a water molecule with the environment, which is due to polarization effects.


Interactions of aminopyridines with potassium channels of squid axon membranes. The effects of aminopyridines on ionic conductances of the squid giant axon membrane were examined using voltage clamp and internal perfusion techniques. 4-Aminopyridine (4-AP) reduced potassium currents, but had no effect upon transient sodium currents. The block of potassium channels by 4-AP was substantially less with (a) strong depolarization to positive membrane potentials, (b) increasing the duration of a given depolarizing step, and (c) increasing the frequency of step depolarizations. Experiments with high external potassium concentrations revealed that the effect of 4-AP was independent of the direction of potassium ion movement. Both 3- and 2-aminopyridine were indistinguishable from 4-AP except in potency. It is concluded that aminopyrimidines may be used as tools to block the potassium conductance in  excitable membranes, but only within certain specific voltage and frequency limits.


Multiple excitations in photosynthetic systems. The yield of fluorescence in Chlorella from a 7 ns pulse of light is found to decrease gradually as a function of the number of hits in the photosynthetic units. The fivefold decrease in yield is spread over some three orders of magnitude of pulse energy and strongly suggests another random process in addition to that of photon absorption. Evidence supports the view that this random process is not in the time but in the spatial domain. The model used to fit the data is that of a unit with multiple traps for the singlet excitation. An excitation is captured by an open trap or destroyed by a filled trap with equal probability. These studies give evidence for the connectivity of the photosynthetic energy transfer apparatus on the short time scale. The short fluorescence lifetimes following picosecond pulse excitation of photosynthetic systems reported by several laboratories may be explained by the effect of multiple excitations.


Globin chain synthesis in HbD (Punjab)-beta-thalassemia. A 23-yr-old man of Greek-Italian ancestry with mild anemia was found to be heterozygous for HbD (Punjab) beta121 glu leads to gin and beta-thalassemia. HbA was not detected upon electrophoresis of the subject's hemolysate, and no synthesis of betaA globin was demonstrated after incubation of peripheral blood or bone marrow with 3H-leucine. The thalassemia gene was thus of the betao variety. The betaD/alpha synthesis ratios were almost equally unbalanced in the blood and bone marrow: 0.53 and 0.61, respectively. The mother of the propositus had beta-thalassemia trait. In peripheral blood the betaA/alpha synthesis ratio was 0.38. The mutant betaD gene thus appeared potentially capable of directing the synthesis of globin chains as efficiently as a normal betaA gene. The mildness of the HbD-betao-thalassemia syndrome appeared to be due to the maintenance of a relatively high total beta/alpha synthesis ratio in the presence of a physiologically neutral structural mutation.


Hybrid erythrocytes for membrane studies in sickle cell disease. A hybrid erythrocyte model for membrane studies in sickle cell disease has been developed. The model consists of normal red cell membranes containing hemoglobin S and sickle cell membranes containing hemoglobin A. In hybrids, complete hemoglobin exchange has been achieved together with restoration of low membrane permeability to potassium. Normal membranes containing HbS sickle upon deoxygenation and assume the characteristic appearance of irreversibly sickled cells (ISC) after prolonged anoxia. It is suggested that the hybrid model will be useful in defining further the process of ISC formation and in studying the influence of sickle hemoglobin upon the function of the surrounding membrane.


Micropinocytosis of transferrin by developing red cells: an electron-microscopic study utilizing ferritin-conjugated transferrin and ferritin-conjugated antibodies to transferrin. Electron-microscopic examination of rat reticulocytes and normoblasts incubated with transferrin conjugated to ferritin or ferritin-labeled antitransferrin revealed binding of ferritin conjugates to the surface membrane, and uptake of ferritin conjugates in micropinocytotic vesicles. No binding or endocytosis of ferritin was visualized when rat reticulocytes or normoblasts were incubated with ferritin alone or ferritin conjugated to nonspecific rabbit IgG. These observations support the concept that transferrin binds to a surface membrane receptor and is subsequently internalized by the developing red cell. Time course and temperature dependence studies suggest the endocytosis of transferrin may be an important mechanism in delivery of iron to the developing red cell.


Hemin reversal of benzene-induced inhibition of reticulocyte protein synthesis. Benzene (0.056-0.113 M) rapidly and reversibly inhibited protein synthesis in anucleate human sickle cell and rabbit reticulocytes. Hemin (50 muM) both prevented and reversed this effect of benzene. The inhibition in rabbit reticulocytes was accompanied by a conversion of polyribosomal disaggregation required ribosomal movement along mRNA and was also prevented and reversed by 50 muM hemin. Benzene was also shown to inhibit heme synthesis in rabbit reticulocytes while neither ATP nor GSH levels were altered. A translational repressor (HCR) of reticulocyte cell-free protein synthesis was isolated from intact cells incubated with benzene, while no significant amount of HCR was found in cells incubated with both benzene and hemin. These results indicated that benzene inhibits translation at the heme-dependent site of initiation. The clinical implications of these experiments remain to be elucidated.


Erythropoiesis-inhibiting factor(s) (EIF): methodologic studies. Erythropoiesis-inhibiting factors (EIF) have been demonstrated in plasma from hypertransfused animals and from polycythemic individuals during periods of hyperoxia, but there is a decided discrepancy in the data published. In the present paper methodologic variations of a bioassay for demonstrating the erythropoiesis-inhibiting factor are discussed. In these studies no inhibitor of erythropoiesis could be demonstrated in plasma from hypoxia-induced polycythemic mice (HPM) on posthypoxic day 5. Injections of RBC or an equal amount of hemolyzed RBC were capable of suppressing the stimulatory effects of ESF, indicating that a red cell constituent may be responsible for the inhibitory effect observed. Transfusion-induced polycythemic mice (TPM) were therefore considered to be less suitable for demonstrating erythropoiesis inhibitors. Our results from testing several doses of a urinary EIF in normal mice, TPM and HPM, indicated that the HPM provided the most sensitive assay system. A similar effect was obtained with hypoxia-induced polycythemic rats. The most marked effect was seen in HPM when the EIF was injected shortly before administering the ESF, while the effect was less pronounced when the EIF was injected 24 hr before or after the ESF.


The fate of thymic radioactivity after local labeling with 125iododeoxyuridine. The thymic cortex was locally labeled with 125Iododeoxyuridine (125IUdR) in young adult mice in an attempt to provide a simple quantitative assessment of the fate of cortical thymocytes. Similarly operated and nonoperated mice given 125IUdR intravenously were used for comparison. Analogous experiments were performed in adrenalectomized animals. More than 90% of thymic activity present 1 day after labeling had been lost by day 8. That proportion of radioactivity contributed to a given organ by accumulation of labeled thymic migrants was estimated by comparison of values obtained after local labeling with those acquired after systemic labeling. Thymic cell accumulation was apparent in the intestine, spleen, mesenteric lymph node, and femurs of locally labeled mice; however, only a few per cent of the total activity lost from the thymus was accounted for in these lymphoid organs. The pattern of fecal and urinary elimination of 125I did not markedly differ in the various experimental groups, the bulk of the activity being recovered in the urine. The intestine could not be ruled out as a major site of thymocyte loss. Since significant radiation or pharmacologic toxicity was unlikely with the doses of 125IUdR used, the data indicated that the vast majority of newly formed thymocytes dies after a short life and only a small fraction of thymic migrants is longer lived.


Matching of histocompatibility (HL-A) antigens for platelet transfusion. The average in vivo platelet survival was measured by both per cent recoveries (%R) and half-lives (t 1/2) of 51Cr-labeled platelets in 69 transfusions given to 43 thrombacytopenic patients. The results demonstrated that (1) increase in the number of HL-A incompatibilities in the platelet donor was significantly associated with decreased %R and t 1/2 of the infused platelets; (2) survival of transfused platelets from HL-A-matched single donors was consistently superior to those pooled from several grossly mismatched donors; and (3) survival of platelets infused when patients had circulating lymphocytotoxic antibodies was consistently lower than when patients did not have such antibodies, regardless of whether it was the first, second, or third such infusion.


G-banding analysis of complex aneuploidy in multiple myeloma bone marrow cells. Chromosome studies with the banding technique have been performed in a considerable number of cases of myeloproliferative diseases, but technical difficulties have so far prevented detailed studies of chromosomal abnormalities in multiple myeloma. The karyotypes of bone marrow cells from two patients with multiple myeloma have been analyzed by a trypsin-Giemsa banding technique. Evidence is given for clonal evolution which in one patient has probably occurred by cell fusion and subsequent chromosome loss. Eight different marker chromosomes are characterized. Nonrandom chromosomal participation in the translocations and the existence of specific vulnerable points on chromosomes 1, 3, and 16 are suggested.


Hb Leslie, an unstable hemoglobin due to deletion of glutaminyl residue beta 131 (H9) occurring in association with beta0-thalassemia, HbC, and HbS. A new unstable hemoglobin, Hb Leslie, has been observed in three generations of a Georgia family. The propositus, a 42-yr-old black veteran with hemolytic anemia and splenomegaly, has a hemoglobin variant with an electrophoretic mobility similar to that of hemoglobin F. The variant comprises about 85% of the total hemoglobin and was isolated by chromatography. Chemical analysis has identified the abnormality as a deletion of the glutaminyl residue in position 131 (H9) of the beta-chain. Deletion of this critical residue which participates in the alpha1beta1 contact causes decreased stability of the hemoglobin without significant changes in functional properties or morphologic abnormalities in the erythrocyte. Family studies revealed hemoglobin Leslie occurring in combination with beta0-thalassemia, HbS, and HbC. All persons with the various Hb Leslie combinations, including the propositus, have no clinical manifestations other than anemia. In some the anemia is fully compensated. There is no history of drug-associated hemolysis.


Study of a kindred with hereditary spherocytosis and glyceraldehyde-3-phosphate dehydrogenase deficiency. A patient with hereditary spherocytosis (HS) was found to have glyceraldehyde-3-phosphate dehydrogenase (G3PD) deficiency by electrophoresis of the isolated red cell membranes on polyacrylamide gels with sodium dodecyl sulfate (PAGE SDS) as demonstrated by a diminished band 6 (G3PD) and confirmed by specific enzyme assay. Thirteen members of his family were studied: four were normal, two had HS alone, three had G3PD deficiency alone, and four had both HS and G3PD deficiency. G3PD deficient kindred members were probably heterozygous, since their red cell enzyme, while qualitatively normal, was present in half normal amounts. The G3PD deficiency alone was asymptomatic, and there was no evidence that the combination of HS with G3PD deficiency increased the clinical severity of the disease. However, G3PD deficiency, when combined with HS, was associated with an increase in protein band 4.5 on PAGE SDS. This band was also increased by incubation of normal red cells without glucose, and appeared to be a protein absorbed to the membrane as a consequence of metabolic stress. Hence, red cells with the combined abnormalities of both HS and G3PD deficiency showed signs of the exceptional metabolic stress to which they were exposed.


A new method for studying splenic reticuloendothelial dysfunction in sickle cell disease patients and its clinical application: a brief report. Differential interference contrast (DIC) microscopy (Nomarsky optics) readily demonstrates the formation of "pits" or crater-like depressions in red cell membranes of splenectomized individuals. Splenic reticuloendothelial dysfunction characteristic of many patients with sickle cell disease (SCD) can be demonstrated by technetium spleen scans, but this technique is expensive, requires injection of radioactive material into children, and is cumbersome to perform at regular intervals. However, pit formation in red cells, which also appears to reflect splenic dysfunction, can readily be quantitated in a finger-stick blood sample using DIC microscopy. In this study, the degree of red cell pitting was compared with results of technetium spleen scans and measurements of Howell-Jolly bodies in individuals with sickle cell disease. The average pitted cell percentage in the control population was 0.5% +/- 0.5 (range 0.0-2.6) and 30.5% +/- 13.9 in the SCD population (range 2.4-71.1) (less than 0.001). Of the individuals studied with SCD, 12 also had technetium (99mTc) sulfur colloid scans and measurements of Howell-Jolly bodies. The percentage of Howell-Jolly bodies was low and did not correlate well with the degree of splenic visualization. However, there was an excellent correlation between pit count and splenic dysfunction as measured by spleen scan. Determination of red cell pitting, therefore, appears to offer a simple means for clinical evaluation of splenic reticuloendothelial function in patients with SCD.


Lipid synthesis in human erythroid cells: the effect of sickling. Human reticulocytes are capable of synthesizing membrane lipids from 14C-glycerol de novo. In both sickle and nonsickle reticulocytes the majority of 14C-glycerol was incorporated into phospholipids, primarily phosphatidylserine and phosphatidylcholine. Incorporation into sphingomyelin was minimal. The most abundant neutral lipid synthesized was triglyceride. In the absence of sickling, the rate of lipid synthesis in sickle reticulocytes was similar to that of nonsickle reticulocytes. With the induction of sickling under anoxic conditions sickle reticulocytes showed a prompt increase in the rate of lipid synthesis to an average of 69% above control values, while nonsickle reticulocytes under similar conditions decreased the rate of lipid synthesis. An increase in the rate of membrane lipid synthesis is associated in the mammalian erythroid cell with cell membrane damage. The findings further confirm that lesions of the erythroid cell membrane in sickle cell anemia are secondary to the sickling process itself.


Red cell calcium leak in congenital hemolytic anemia with extreme microcytosis. A child with congenital hemolytic anemia, extreme microcytosis and bizarre red cell morphology has been studied. Splenectomy at the age of 21 mo greatly improved the hemolytic anemia, although red cell morphology was unchanged. Aniso- and poikilocytosis were marked on a stained smear, and there were many small hyperchromatic cells of irregular shape. The MCV of 25 cu mu was very low and the MCHC was normal. Osmotic fragility of fresh blood was increased, and postsplenectomy blood showed a fraction of extremely fragile cells. Concentration and fluxes of Na+ and K+ were normal, except K+ efflux, which was stimulated by external Ca2+. Inward Ca2+ movement into the patient's red cells was elevated three- to fourfold above red cells of the same mean age. Red cell Ca2+ concentration was raised 2.5 times normal and most of the Ca2+ was localized in the stroma. Red cell lipid, sialic acid, and ouabain-binding sites, all per milliliter of cells, were increased by 16%-23%, and, since these substances estimate the amount of membrane, it was likely that Ca2+ content per unit of membrane area was at least twice normal. Deformability of the cells, as judged by their filterability was markedly impaired. It was concluded that the red cell membrane was defective, and an increased membrane Ca2+ content was associated with reduced deformability, hemolysis, and distorted red cell morphology in this syndrome.


Effect of splenectomy on tolerance to combination chemotherapy in patients with lymphoma. Enhanced tolerance to combination chemotherapy has been cited as an ancillary benefit of staging laparotomy and splenectomy in Hodgkin's disease. Seventeen patients with Hodgkin's disease and 15 with non-Hodgkin's lymphoma were subjected to nontherapeutic splenectomy as part of the staging procedure prior to their initial treatment with MOPP (nitrogen mustard, vincristine, procarbazine, and prednisone) or CVP (cyclophosphamide, vincristine, and prednisone) chemotherapy, respectively. Matched control patients of comparable age, pathologically proven stage, and presence or absence of bone marrow lymphoma and previous radiotherapy were selected. Although leukocyte (in non-Hodgkin's patients) and platelet counts (in both groups) were significantly higher in the patients with splenectomy during most of the first six cycles of therapy, there was no difference in the number of cycles during which a leukocyte count below 1000 (or below 2000 in Hodgkin's disease) or platelet count below 50,000 was recorded in the splenectomized and control patients. The total dose of all drugs actually delivered, time required to complete six cycles of treatment, and the portion of patients entering complete remission were not significantly different in the two groups. We have found no evidence that splenectomy per se, in lymphoma patients without findings of hypersplenism, improves the ability to administer planned amounts of drugs during initial combination chemotherapy.


Preleukemia and leukemia in polycythemia vera. A group of 76 polycythemia vera patients was followed prospectively with bone marrow examinations at regular intervals. Six terminated in acute leukemia, preceded by an indolent preleukemic phase succeeded by a very fulminant leukemia. At autopsy, all patients had extramedullary hematopoiesis. In one of them, only the bone marrow was leukemic, suggesting that it was the primary site of this transformation. In three with leukemic involvement of nonhematopoietic organs, the infiltrate consisted of myelo- or myelomonoblasts and normoblasts. The preleukemic phase was characterized by a rapidly evolving spontaneous pancytopenia, with a drop from polycythemic blood counts within 2 mo. In the bone marrow, megaloblastoid erythropoiesis with ring sideroblasts was prominent. A similar preleukemic phase evolving in other potentially leukemic conditions, has been described. Therefore, in patients at risk, the appearance of ring sideroblasts may be regarded as an early indicator of imminent acute leukemic transformation.


Evidence that Fitzgerald factor counteracts inhibition by kaolin or ellagic acid of the amidolytic properties of a plasma kallikrein. Fitzgerald trait, an asymptomatic disorder, is associated with abnormalities of surface-mediated plasma reactions, including coagulation via the intrinsic pathway, augmentation of the clot-promoting properties of factor VII, kaolin-mediated fibrinolysis, kinin generation, and enhancement of vascular permeability by diluted plasma (PF/Dil). These abnormalities can be corrected by Fitzgerald factor, an agent probably identical with high molecular weight kininogen found in normal, but not Fitzgerald-trait plasma. Our preparations of Fitzgerald factor possessed a second property. Amidolysis of alpha-N-benzoyl-L-proline-L-phenylalanine-L-arginine-pnitroanilide by a plasma kallikrein (activated Fletcher factor) was inhibited by kaolin or solutions of ellagic acid. Addition of preparations of Fitzgerald factor to kaolin or to solutions of ellagic acid counteracted their inhibitory properties. The action of these preparations was duplicated by solutions of cytochrome C or IgG, suggesting that these agents may inhibit the negative charges of kaolin or ellagic acid. Fitzgerald factor enhanced amidolysis of both normal and Fitzgerald-trait plasmas exposed to kaolin, effects not duplicated by cytochrome C or IgG. Whether or not the two properties of our preparations of Fitzgerald factor are related to the same agent is not yet certain. The relationship between these observations and the biologic role of Fitzgerald factor remains to be investigated.


Infectious canine hepatitis: animal model for viral-induced disseminated intravascular coagulation. The objective of this study was to characterize the hemostatic defect in dogs with infectious canine hepatitis (ICH), a naturally occurring viral disease of dogs. Five littermate dogs were inoculated with 10(3) TCID50 of ICH virus intravenously. Two littermates were controls. The clinicopathologic manifestations of ICH were fever, depression, anorexia, hematemesis, melena, widespread mucocutaneous petechiae, prolonged bleeding from venipunctures, faceial edema, leukopenia, and proteinuria. The hemostatic defect of ICH was characterized by thrombocytopenia, abnormal platelet function, prolonged one-stage prothrombin time and activated partial thromboplastin time, normal thrombin times, depressed factor VIII activity, and increased fibrin-fibrinogen degradation products. These findings suggested that the central pathologic mechanism of the abnormal hemostasis in ICH was disseminated intravascular coagulation (DIC). ICH is an example of DIC induced by viral infection. This disease is a suitable model for investigation of the detection, pathogenesis, and therapy of DIC.


A study of the large heparin requirements in the generalized Shwartzman reaction. The heparin requirements necessary to inhibit intravascular fibrin deposition and soluble fibrin monomer (FM) formation in the generalized Shwartzman reaction (GSR) were evaluated. Fibrin deposition was measured by a quantitative technique utilizing 125I-labeled rabbit fibrinogen. FM was measured semiquantitatively by gel exclusion chromatography and by the serial dilution protamine sulfate (SDPS) test. There was a fourfold increase in heparin requirement 5 min after compared with 5 min before the second dose of endotoxin. This increase in heparin requirement was not related to thrombin elaboration, since FM was not found until more than 1 hr after the second dose of endotoxin. Neither was there any evidence of diminished sensitivity to the anticoagulant effect of heparin. The heparin requirements in the GSR rabbits were found to be in excess of those needed to neutralize a defibrinating dose of thrombin. It was concluded that a potent, heparin-resistant clotting activity developed within 5 min of the second endotoxin injection. The mechanism by which the activity caused the gradual elaboration of a thrombin-like enzyme is diffucult to explain on the basis of traditional coagulation reactions. The apparent role of white cells is discussed.


Pluripotential stem cell differentiation in hemopoietic colonies. To determine if mononuclear cells proliferating in murine hemopoietic spleen colonies were pluripotential in addition to possessing kinetic features of stem cells, we performed sequential studies of mice during their recovery from a split-dose irradiation regimen of 850 roentgens leg shielded-3-hr interval-850 roentgens leg irradiated (850R L.S. 3- L.I.). Injecting tritiated thymidine during stem cell compartment repletion 3 and 4 days after 850R L.S. 3- L.I. resulted in heavily labeled mononuclear cells resembling medium to large leptochromatic lymphocytes in the portion of spleen removed an hour after injection. The splenic remnant obtained from the same mouse 24-48 hr later contained lightly labeled erythroblasts, myeloid cells, and lymphoid cells. Grain counts suggested that erythroblasts and their precursors had undergone about four divisions, myeloid cells and their precursors two to three divisions, and lymphoid cells and their precursors two to three divisions during the 48-hr period. Similar studies in plethoric mice demonstrated the labeling of mononuclear cells on day 4 and their differentiation to myeloid and lymphoid cells by day 6. This finding confirmed that the labeled mononuclear cells were not exclusively erythroblast progenitors. On the basis of these and previous studies of post-irradiation survival and erythropoietic recovery, we conclude that these endogenous monomuclear cells, which resemble medium to large leptochromatic lymphocytes and replicate during stem cell compartment repletion, are pluripotential hemopoietic stem cells.


Increased erythropoietin production in anephric rats with hyperplasia of the reticuloendothelial system induced by colloidal carbon or zymosan. Adult rats were subjected sequentially to (1) administration of colloidal carbon, zymosan, or gadolinium; (2) subtotal hepatectomy, bilateral nephrectomy, or sham operation; and (3) a 6-hr bout of hypoxia, starting 1 hr or 24 hr after the operation. Control animals received the respective vehicles. The erythropoietin (Ep) activity was assayed in exhypoxic polycythemic mice on the basis of 48-hr per cent RBC(-59) Fe incorporation values. Ep levels in serum of anephric rats primed with either colloidal carbon or zymosan were considerably more elevated than in control animals. This potentiating effect was observed in rats subjected to hypoxia starting either 1 or 24 hr after nephrectomy. On the other hand, gadolinium did not enhance the extrarenal Ep response to hypoxia. It is emphasized that both colloidal carbon and zymosan induced marked hyperplasia of the hepatic and splenic reticuloendothelial system (RES), while gadolinium did not induce this effect. A strict correlation was thus established between potentiation of extrarenal Ep production and hyperplasia of the RES. It is therefore tentatively concluded that the RES is a source of extrarenal Ep. Additionally, since the liver plays a prominent role in extrarenal Ep production, Kupffer cells may represent a major source for Ep in the anephric rat. Finally, it is of interest that both colloidal carbon and zymosan did not potentiate the Ep response to hypoxia in sham-operated or subtotally hepatectomized rats.


Pattern and quality of recording pre-admission drug treatment in paediatric patients. The pattern and quality of recording drug use before admission was examined in children admitted to a paediatric unit over eight months. The preadmission drug intake (1-7 drugs/patient) was lower than that of adults. Antibiotics were the most frequently prescribed drugs, but mild analgesics and antihistamine preparations were commonly used, often without medical advice. The simultaneous administration of prescribed and non-prescribed drugs appeared to be as common in children as in adults. The number of drugs taken was related to the number of domicilary consultation received and the number of doctors seen as as to confirm that most doctors' visits result in the prescription of medicine. The transfer and recording of drug information was poor, owing principally to lack of communication between doctors and failure to detect self-medication, but the modern practices of self-referral to hospital and use of multiple prescribers have further reduced the information available. The use of a "current treatment card" is required if the full significance of iatrogenic disease in childhood is to be investigated.


Measles-virus-specific IgG in optic neuritis and in multiple sclerosis after optic neuritis. Measles-virus-specific IgG was measured in the serum of 100 patients who had presented with optic neuritis (ON) during 1960-74. When reviewed 41 of them were found to have developed definite symptoms and signs of multiple sclerosis (MS), their serum containing significantly higher titres of the antibody than sera from either the rest of the patients or a group of normal healthy controls. In a few patients from whom cerebrospinal fluid (CSF) was obtained in the acute phase of ON, titres of measles IgG in the serum was higher in those in whom the antibody was detected in the CSF than the serum of patients without CSF antibody.


Climate and painful crisis of sickle-cell disease in Jamaica. In a 10-year retrospective study a close correlation was found between low temperatures and hospital admissions for severe painful crises of sickle-cell disease.


Cervical diameter after suction termination of pregnancy. The diameter of the internal cervical os was measured in several groups of patients in an attempt to assess any damage caused by suction termination of pregnancy. Pregnant women who had had a previous abortion by vacuum aspiration had significantly greater cervical diameters than those who had not, and there was a statistically significant correlation between dilatation of the cervix at operation and cervical diameter at six weeks' follow-up. Cervical dilatation to 10 mm or less was subsequently associated with a normal cervical diameter, but the diameter was often large when the extent of dilatation was greater than 12 mm or not known. Cervical dilatation at termination of pregnancy should, if possible not exceed 10 mm.


Value of determination of oxygen consumption in tetanus. Oxygen consumption (VO2) was determined in 10 patients with moderate tetanus. The mean (+/- SE) VO2 of 425-2-2 +/- 50-3 ml/min on admission fell significantly to 249-9 +/- 13-1 ml/min standard temperature and pressure dry (STPD) after parenteral diazepam. There was also a significant fall in minute ventilation after administration of diazepam. The results suggest that the simple practical determination of VO2 will be of immense value in assessing the efficacy of muscle relaxants, assessing the severity of tetanus, and determining the calorie needs of patients.


Assessment of preoperative cases.

Assessment of preoperative cases. A total of 200 outpatients in Aberdeen were invited to complete a simple preoperative anaesthetic assessment questionnaire. Of these patients 45-5% had significant medical histories and 59% were on concurrent drug therapy. The form was thought to be valuable for day-case anaesthetists and surgeons.


Critical appraisal of domiciliary obstetric and neonatal practice. Obstetric and neonatal data on 155 domiciliary deliveries were analysed. The findings illustrated the problems in adhering to generally recognised risk criteria for selecting cases for domiciliary confinement and the unpredictability of events in the newborn period. Awareness of the risks of home confinement have led to increased efforts to achieve 100% hospital delivery. At the West Middlesex Hospital, to make hospital confinement more acceptable to mothers, we have tried to alter inflexible hospital routines and to make previously austere labour wards less impersonal. The same midwife who has supervised the antenatal period brings the mother into the unit, and transfers her home as soon as possible afterwards..


Completely isolated molluscan neurons. An ultrastructural study. The neurons of the molluscs Lymnaea and Helix isolated by fermentative digestion followed by mechanical treatment do not differ ultrastructurally from intact ones. These cells have sufficient metabolic reserves and incorporate into RNA 8% of the total radioactive pool, even more than neurons in ganglia under equal conditions. Neuronal damage can occur, mainly during the pipetting, and this is usually expressed in vacuolization of the cytoplasm. It is important to note that alterations in cell ultrastructure develop earlier than changes in the membrane electrical properties. The surface of the isolated neurons is enlarged two-fold due to the infoldings of the cell membrane. So, the specific resistance of soma membrane of these neurons was calculated as 78 +/- 13 komega-sq. cm. On the surface of isolated neurons scraps of glial and neuronal processes not connected with their own cell bodies, and as a consequence not powerful, are sometimes found. Some endings of the neuronal processes on the surface of isolated neurons are ultrastructurally similar to the axo-somatic synapses.


Dorsal raphe stimulation produces inhibitory effect on trigeminal nucleus neurons. Inhibitory effects of conditioning stimulation of the dorsal raphe nucleus (DR) on the neuron activity in the rostral part of spinal trigeminal nucleus (STN) were studied in cats for the purpose of comparison with the inhibition induced by locus coeruleus (LC) stimulation. DR conditioning stimulation reduced the orthodromic field potential in STN elicited by inferior alveolar nerve stimulation, and enhanced the antidromic field potential in the trigeminal nerve evoked by STN stimulation; but the inhibitory effects of DR stimulation were considerably weaker than those of LC stimulation. In tracking experiments near the raphe nucleus, conditioning stimulation of DR itself produced the most pronounced decrease in the STN field potential. Orthodromic spike number of STN relay neurons was significantly reduced by DR conditioning stimulation; however, the threshold for the conditioning stimulus to the DR was much higher than that to the LC. Antidromic spike generation of the STN neurons was unaltered by conditioning stimulation of both DR and LC. DR stimulation elicited a field potential in STN, which followed high frequency stimuli up to 200 HZ. A single fiber action potential was also obtained in STN by DR stimulation. STN stimulation produced a field potential in DR, which followed high frequency stimuli. It is suggested from these findings that conditioning stimulation of DR produces a direct inhibition of transmission in STN neurons; however, this stimulation has less effect on these neurons than does stimulation of the LC.


Single unit responses recorded from the first order neuron of the pigeon auditory system. Intracochlear recordings from the first order neurons in the eighth nerve of the pigeon were made with microelectrodes. The basic response characteristics of the single units were similar to those recorded from mammalian first order auditory neurons with the following exceptions: units responding solely to 'sweep frequencies' were found and one unit was found for which the rate of discharge decreased with increased intensity. Suppression of spontaneous activity during tonal stimulation was found within the response curve of the unit and for frequencies beyond the boundaries of the response curve. In addition, suppression of spontaneous activity was found after the termination of the tone. The amount of suppression and the recovery process varied considerably from unit to unit. The controlling variables were intensity and duration of the stimulus.


Kinetics of potassium movement in norman cortex. Artificial CSF containing 12mEq/1 of potassium (4 times normal concentration) was perfused over the surface of normal neocortex in 10 locally or barbiturate anesthetized cats. Extracellular potassium concentrations ([K+]OS) were measured as a function of time to 8 h and of depth to 3 mm. Analysis of the [K+]O versus depth and [K+]O versus time profiles showed that the distribution of extracellular potassium could be modelled by a process of diffusion with diffusion coefficient = 1.03 +/- 0.16 sq.mm/h, and a surface barrier to diffusion with magnitude given by a barrier constant 0.8 +/- 0.2 mm-1, and with a small correction for active uptake into cells and blood vessels. The profiles obtained differ considerably from those which could be predicted from kinetic properties of potassium in aqueous solution.


Spontaneous and electrochemically stimulated changes in plasma LH in the female rat following hypothalamic deafferentation. Plasma LH levels in adult female rats were studied by radioimmunoassay 6 weeks after making frontal cuts (FC) at the optic chiasm with Halász knives of various sizes. Cuts made with a small knife (radius 1.3 mm) permitted a spontaneous rise in plasma LH during proestrus from a mean of 96 +/- 25 ng/ml at 14:00 h to 545 +/- 207 ng/ml at 18:00 h in 13 rats. Seven of the latter, with a mean plasma LH of 967 +/- 281 ng/ml at 18:00 h exhibited tubal ova at hemicastration (hemi-ovx) the following morning. In a similar experiment 6 FC females lesioned with a 1.5 mm knife had plasma LH levels of 53 +/- 7 ng/ml at 14:00 h, but showed neither detectable changes at 2 h intervals through 20:00 h nor ovulation at hemi-ovx. Similar results were obtained in 13 rats deafferented with a 2.0 mm knife. Nine weeks after FC and 3 weeks following hemi-ovx all animals were given pentobarbital (32 mg/kg i.p.) at 13:30 h and stimulated bilaterally in the medial preoptic area (MPO) passing 20 muA anodal DC X 60 sec through concentric bipolar steel electrodes placed 0.8 mm from the midline. All 3 groups of FC animals showed increases in plasma LH to comparable levels (range: 197 +/- 45-357 +/- 156 ng/ml) 1 h after stimulation. Electrochemical stimulation sites extended lateral to the cut locations on at least one side in all animals. The results of these studies suggest that chronically (9 week) deafferented female rats have the capacity to release pituitary LH in response to MPO electrochemical stimulation in spite of retrochiasmatic deafferentation, but that the ovaries of the persistent estrus rat are unresponsive to these amounts of circulating LH.


Brain stem self-stimulation attenuated by lesions of medial forebrain bundle but not by lesions of locus coeruleus or the caudal ventral norepinephrine bundle. Midbrain tegmental intracranial self-stimulation (ICSS) was not attenuated by ipsilateral or bilateral locus coeruleus lesions. Certain of these lesions were followed by histochemical confirmation that the majority of locus coeruleus neurons was destroyed, and biochemical evidence that over 80% of the cortical norepinephrine was depleted. To test the possibility that the surviving ICSS was due to stimulation of another norepinephrine system, histochemically verified ipsilateral or bilateral lesions of the ventral norepinephrine bundle were administered to a second group of midbrain tegmental ICSS animals. These lesions resulted in marked loss of body weight, but had no effect on ICSS. In a third experiment, lesions were made in the medial forebrain bundle (MFB) ipsilateral to midbrain tegmental ICSS electrodes. These lesions resulted in attenuation of ICSS which was directly proportional to the extent of MFB damage. On the basis of these data alone, however, it was not possible to identify the ciritical fibers supporting ICSS. It was oncluded that the locus coeruleus does not play a necessary role in midbrain tegmental ICSS.


Time course and disposition of fucose radioactivity in rat hippocampus. A biochemical and microautoradiographic study. Male adult rats were injected intraventricularly with L-[1-3H]fucose. At various intervals, ranging between 30 min and 11 days, one-half of the brain was prepared for microautoradiography, and the hippocampus from the other side was prepared for biochemical investigations. The TCA-precipitable proteins from the hippocampus homogenate were maximally labeled at between 8 and 24 h and remained at a high radioactivity level even 11 days after [3H]-fucose injection, the labeling being predominantly present in the solubilized insoluble proteins. Using gel electrophoretic separation, study of Tris-soluble material indicated a rapid turnover of soluble fucose-containing glycoproteins, whereas several slow-migrating bands of solubulized proteins revealed a time course suggesting the presence of fucose-containing glycoproteins with slower turnover rates. Using microautoradiography, a rapid labeling of neuronal cell bodies of the hippocampus was found, whereas the nuclei were not labeled. Perikarya were maximally labeled 4 h after [3H]fucose application. The radioactive material was continuously transported from the soma into the corresponding fiber layers, the latter being maximally labeled at a pulse interval of one day; even 10 days later a considerable amount of radioactivity could be detected in the neuropil.


Increased fucose incorporation into rat hippocampus during learning. A biochemical and microautoradiographic study. The incorporation of intraventricularly infected L-[1-3H]fucose into proteins of the hippocampus and visual cortex was studied during the acquisition of a shock-motivated brightness discrimination in rats. The labeling of Tris-soluble proteins from both regions was not significantly changed during learning, whereas solubilized insoluble proteins obtained from the hippocampus revealed an increased fucose incorporation in learned animals. A significant enhanced incorporation into some distinct, slow-moving, carbohydrate-rich protein bands, separated by polyacrylamide gel electrophoresis, was observed in material from CA1 and CA3 sectors as well as from area dentata of the hippocampus formation during acquisition. The corresponding gel bands from the visual cortex exhibited no differences between trained animals and controls. Jointly performed microautoradiography showed an increased fucose incorporation into most areas of the hippocampus in learned animals compared with active and passive controls. The most significant differences were found to occur mainly in substructures consisting of densely packed neuronal cells.


Regional changes in monoamine content and uptake of the rat brain during postnatal development. Regional norepinephrine (NE), dopamine (DA) and serotonin (5-hydroxytryptamine, 5-HT) contents in the developing rat brain were estimated. The rate of increase in NE content was the highest in diencephalon, followed by the lower brain stem, limbic-striatum, neocortex and cerebellum. With postnatal aging, DA concentration increased markedly in limbic-striatum, slightly in the neocortex and negligibly in other regions. In each region except cerebellum, 5-HT content increased gradually but the rate of increase in diencephalon was relatively high. Comparison of the kinetics of high affinity uptake of L-[3H]NE and [3H]5-HT between the neonatal and the adult brain indicated that Km values of L-[3H]NE and [3H]5-HT uptake were 2.9 X 10(-7) M and 1.7 X 10(-7) M respectively in neocortex, diencephalon and lower brain stem and 4.3 X 10(-7) M and 2.3 X 10(-7) M in limbic-striatum in the neonate as well as in the adult. Vmax values of both amines uptake differed regionally and the values in the neonate were lower than those in the adult in all regions. Limbic-striatum showed a higher Vmax value than other regions in uptake of both amines. These results suggested that innervation of monoaminergic neurons in the brain progressed with increasing age, that projections of both NE and 5-HT neurons were relatively high into hypothalamus and limbic-striatum and that DA neuron projections concentrated at striatum. Although the brain, except for limbic-striatum, showed neither regional nor developmental differences in affinity of L-[3H]NE and [3H]5-HT to synaptosomes, the density of nerve terminal of both monoaminergic neurons increased in all regions of the brain during postnatal development. In limbic-striatum, higher Km and Vmax values of both amines, uptake suggest the existence of both amines' uptake into DA terminal to some extent.