Tryptophan biosynthetic enzymes of Staphylococcus aureus. Tryptophan biosynthetic enzymes were assayed in various tryptophan mutants of Staphylococcus aureus strain 655 and the wild-type parent. All mutants, except trpB mutants, lacked only the activity corresponding to the particular biosynthetic block, as suggested previously by analysis of accumulated intermediates and auxonography. Tryptophan synthetase A was not detected in extracts of either trpA or trpB mutants but appeared normal in other mutants. Mutants in certain other classes exhibited partial loss of another particular tryptophan enzyme activity. Tryptophan synthetase B activity was not detected in cell extract preparations but was detected in whole cells. The original map order proposed for the S. aureus tryptophan gene cluster was clarified by the definition of trpD (phosphoribosyl transferase(-)) and trpF (phosphoribosyl anthranilate isomerase(-)) mutants. These mutants were previously unresolved and designated as trp(DF) mutants (anthranilate accumulators). Phosphoribosyl anthranilate isomerase and indole-3-glycerol phosphate synthetase enzymes were separable by molecular sieve chromatography, suggesting that these functions are coded by separate loci. Molecular sieve chromatography failed to reveal aggregates involving anthranilate synthetase, phosphoribosyl transferase, phosphoribosyl anthranilate isomerase, and indole-3-glycerol phosphate synthetase, and this procedure provided an estimate of the molecular weights of these enzymes. Tryptophan was shown to repress synthesis of all six tryptophan biosynthetic enzymes, and derepression of all six activities was incident upon tryptophan starvation. Tryptophan inhibited the activity of anthranilate synthetase, the first enzyme of the pathway.


Inducement of a heat-shock requirement for germination and production of increased heat resistance in Bacillus fastidiosus spores by manganous ions. Bacillus fastidiosus, which requires uric acid or allantoin, grows and sporulates on a simple medium containing 59.5 mM uric acid, 5.7 mM K(2)HPO(4), and 2% agar in distilled water. Seventy to ninety percent sporulation was achieved in 96 h. Spores obtained on this medium do not need a heat shock prior to germination. The necessary germination conditions for this organism are 30 C, phosphate or this(hydroxymethyl)aminomethane buffer at pH 7.0, and 5.95 mM uric acid. Sporulation occurred earlier (48 h) and with higher frequency (greater than 99%) when Mn(2+) was added to the growth medium. However, these spores germinated only after heat activation (70 C, 30 min). The effectiveness of heat activation was directly dependent upon the concentration of Mn(2+) in the growth medium; 10(-5) M Mn(2+) was the minimal concentration for the effect. This phenomenon was not found upon addition of Ca(2+), Mg(2+), Fe(2+), Zn(2+), or Cu(2+) to the medium. The Mn(2+) content of the spores depended upon the concentration of Mn(2+) in the sporulation medium. There was a significant difference in heat resistance between spores harvested from unsupplemented medium and those harvested from medium supplemented with 5 x 10(-5) M Mn(2+). A D(85 C) value of 6.5 min was determined with the former, whereas the latter had a value of 17.0 min. Very little change in either Ca(2+) or dipicolinic acid content was detected in spores harvested from various Mn(2+)-supplemented media. Thus Mn(2+) may play a role in the inducement of the heat-shock requirement and the formation of spores with increased heat resistance.


Biosynthesis of branched-chain amino acids in Schizosaccharomyces pombe: regulatory properties of threonine deaminase. Biosynthetic threonine deaminase (TD) from Schizosaccharomyces pombe has been partially purified from crude extracts by treatment with protamine sulfate, ammonium sulfate precipitation, and gel filtration through Sephadex G-25. In both crude extracts and purified preparations, TD showed marked stimulation by pyridoxal phosphate. A pH optimum for activity was found at pH 9.0, whereas the inhibition caused by the natural feedback inhibitor, l-isoleucine, was maximal at pH 7.4. l-Threonine exhibits homotropic cooperative effects at low pH (7.0-8.0), which are eliminated at pH 9.0, and the affinity for substrate (in terms of K(m)) increased with increasing pH. Enzyme activity could be completely inhibited by isoleucine over a pH range of 7.4 to 9.0; the amount of isoleucine required for 50% inhibition increased with increasing pH. Isoleucine inhibition was pseudocompetitive with respect to substrate and increased the cooperative effects of threonine. l-Valine was found to reverse isoleucine inhibition; it also activated the enzyme in a pH range of 7.0 to 8.0 by eliminating the cooperative effects of threonine, thus normalizing the substrate saturation curves at these pH values. l-Leucine was shown to be a competitive inhibitor with respect to threonine, and to be able partially to reverse isoleucine inhibition. Treatment of TD with mercurials did not result in desensitization to isoleucine inhibition. However, at pH 10, virtually no sensitivity of the enzyme to isoleucine was observed while activity remained strong, which suggests the existence of separate sites on the TD molecule for binding threonine and isoleucine. A tentative model is presented which unifies the kinetic results reported here in terms of the interactions of TD with its effector molecules.


Some characteristics of tryptophan uptake in Claviceps species. Tryptophan serves as a precursor for the biosynthesis of alkaloids in the ergot fungus, Claviceps purpurea (Fries) Tulasne, and also is believed to act as an inducer of the enzymes necessary for alkaloid production. The characteristics of the transport system responsible for the accumulation of tryptophan in ergot mycelium were investigated, with the goal of clarifying the complex relationships among tryptophan uptake, size of the free intracellular pool of tryptophan, and alkaloid production. The characteristics of tryptophan uptake were studied by pulse feeding radioactively labeled tryptophan to cultures of Claviceps species, strain SD-58, which represented a variety of ages and nutritional states. Tryptophan accumulation in strain SD-58 is mediated by an energy-requiring system which exhibits specificity for neutral aromatic and aliphatic l-amino acids, is pH and temperature dependent, and shows saturation at high substrate concentrations. Tryptophan transport is a function of the intracellular concentration of free tryptophan, the nitrogen deficiency of the mycelium, the rate of growth, and alkaloid production, which were measured in Claviceps strain SD-58 growth in several culture media, some of which promoted alkaloid production and some of which did not. The results indicate that the initial velocity of tryptophan transport is not directly related to alkaloid production.


Miniature cell formation in Chlamydia psittaci. In an electron microscope study on the developmental cycle of the goat pneumonitis strain of Chlamydia psittaci in L cells, it was observed that miniature reticulate bodies, measuring approximately 0.2 mum in diameter and surrounded by double unit membranes, were produced infrequently from normal-sized reticulate bodies through a "budding"-like process. As little as 0.1 mug of penicillin per ml greatly increased the frequency of the miniature reticulate body formation.


Effects of temperature variation on the fatty acid composition of a psychrophilic Candida species. During the batch cultivation of a psychrophilic Candida species, the proportions of oleic and linolenic acid esters in the cells underwent a cyclic variation regardless of the incubation temperature.


Catalytic studies on tryptophanase from Bacillus alvei. Tryptophanase from Bacillus alvei exhibited the expected spectrum of pyridoxal-5'-phosphate-dependent reactions. It exhibited l-serine dehydratase, S-alkyl-cysteine lyase, and cysteine desulfhydrase activities, as well as the classic tryptophanase reactions (all beta elimination reactions). It also acted as a tryptophan synthetase (beta replacement reactions) using indole plus l-serine or l-cysteine or S-methyl-cysteine as substrates. The beta elimination reactions are simple competitors of the replacement reactions for the same amino acid substrates. The kinetics of the reactions were examined in detail using a coupled continuous spectrophotometric assay. A product (indole) inhibition study of the beta elimination reaction with tryptophan showed simple, noncompetitive inhibition; the same study with allosubstrates showed noncompetitive inhibition by indole. These product studies provided data on the beta replacement reactions as well. The results are discussed in terms of a mechanism for the B. alvei tryptophanase.


Biosynthesis of branched-chain amino acids in Schizosaccharomyces pombe: properties of acetohydroxy acid synthetase. The regulatory properties of acetohydroxy acid synthetase (AHAS), the first enzyme in the biosynthetic pathway to valine and the second in the isoleucine pathway, were investigated in the fission yeast Schizosaccharomyces pombe. The enzyme was partially purified from crude extracts by protamine sulfate treatment, ammonium sulfate fractionation, and gel filtration through Sephadex G-25. AHAS from S. pombe is unique in that its activity shows a single peak around pH 6.5; high sensitivity to feedback inhibition by valine at this pH (K(i) = 0.1 mM) indicates that the enzyme is involved in valine biosynthesis. Pyruvate saturation kinetics of AHAS extracted from cells grown on glycerol as sole carbon and energy source were normal and hyperbolic. In contrast, the enzyme from glucose-grown cells exhibited sigmoidal saturation kinetics, an effect which disappeared when the synthetase from such cells was partially purified. This phenomenon was shown to be due to competition for pyruvate between AHAS and pyruvate decarboxylase; the latter enzyme is present in large amounts in cells fermenting glucose. Valine inhibition is noncompetitive in nature, and this effector exhibits homotropic cooperative effects; isoleucine is a less-potent inhibitor of AHAS activity. Mercurial treatment reversibly desensitized the enzyme to valine inhibition. On the basis of these data, the S. pombe AHAS appears to be an allosteric regulatory enzyme with the properties of a negative V system.


New pathway for nonphosphorylated degradation of gluconate by Aspergillus niger. A new nonphosphorylative pathway for gluconate degradation was found in extracts of a strain of Aspergillus niger. The findings indicate that gluconate is dehydrated into 2-keto-3-deoxy-gluconate (KDG), which then is cleaved into glyceraldehyde and pyruvate. 6-Phosphogluconate was not degraded under the same conditions. In addition, KDG was formed from glyceraldehyde and pyruvate. Very weak activity was obtained when glyceraldehyde 3-phosphate replaced glyceraldehyde in this reaction.


Insensitivity of bacteria to proposed antimetabolites of D-alanyl-D-alanine. alpha-Aminoisobutyryl-d-alanine, d-alanyl-alpha-aminoisobutyric acid, and alpha-amino-isobutyryl-alpha-aminoisobutyric acid, proposed as antimetabolites of d-alanyl-d-alanine in bacterial cell wall synthesis, failed to inhibit bacterial growth.


Fatty acid composition of paracolons: Arizona, Citrobacter, and Providencia. The fatty acid compositions of stationary-phase cultures of Arizona arizonae, Citrobacter freundii, Providencia alcalifaciens, Providencia stuartii, and Providencia sp. were studied. The major fatty acids of A. arizonae, C. freundii, and Providencia were 16:0, 16:1, 17:cyclopropane, and 19:cyclopropane. The fatty acid compositions of the two strains of A. arizonae examined were similar to each other, but the three strains of C. freundii differed from one another in their fatty acid compositions. In both A. arizonae and C. freundii, the relative quantities of saturated, unsaturated, and cyclopropane fatty acids were similar to those which have been found in stationary-phase cultures of other members of the Enterobacteriaceae. The three strains of Providencia also differed from one another in their fatty acid compositions. In all three strains, the total quantity of unsaturated fatty acids was larger and that of the cyclopropane fatty acids was smaller than those found in stationary-phase cultures of other enteric bacteria.


Nucleotide pools and adenylate energy charge in balanced and unbalanced growth of Chromatium. Adenine nucleotide pools and their energy charge were measured during balanced and unbalanced growth of photoheterotrophic Chromatium cultures. The methods used involved rapid sampling, accurate to within 1 s, from isotopically labeled cultures followed by chromatographic separation of individual nucleotides. During balanced growth, both energy charge and adenosine triphosphate (ATP) concentrations, whether expressed as a function of cell protein or intracellular water, were slightly higher in limiting light intensities than in cultures growing at their maximal rate in bright light. The ATP found corresponded to 4.67 +/- 0.08 nmol/mg of protein or 1.34 +/- 0.57 mM for low-light cells and to 4.41 +/- 0.58 mmol/mg of protein or 0.85 +/- 0.12 mM for high-light cells. Corresponding energy charges were 0.85 +/- 0.02 and 0.81 +/- 0.02. Illumination shifts caused differential synthesis of photosynthetic pigments lasting 2 to 3 h without corresponding perturbation of adenine nucleotide levels. Cultures in intermittent illumination were severely affected by some cycle durations; they had abnormal morphology and very high bacteriochlorophyll-to-protein ratios. In such cultures, energy charge and nucleotide concentrations were within normal limits and relaxed to the dark steady state during the dark periods. Arsenate at AsO(4) (3-) to PO(4) (3-) ratios of 10:1 in the medium retarded growth, but no abnormality of charge or quantity of phosphate-containing nucleotides was found. These experiments therefore suggest that, within experimental error, neither the size nor the charge of the adenylate pools governs growth rate in Chromatium. Moreover, these parameters do not appear to be concerned in regulating the synthesis of photosynthetic apparatus in this organism.


The regulation of gluconeogenesis in mammalian liver. The role of mitochondrial phosphoenolpyruvate carboxykinase.


Molecular and catalytic properties of cytosolic acetoacetyl coenzyme A thiolase from avian liver.


Characterization of the pro 1 chain of procollagen. Isolation of a sequence unique to the precursor chain.


Purification and properties of the fatty acid synthetase from Mycobacterium phlei.


Annealing properties of oligoribonucleotides derived from T5 DNA-directed RNA compared to those from T2 and T7 DNA-directed RNAs.


The self-association and oxygen equilibrium of hemoglobin from the lamprey, Entosphenus japonicus.


Titration of activated bovine Factor X.

Titration of activated bovine Factor X.


Defective thyroglobulin synthesis in an experimental rat thyroid tumor. Lack of membrane-bound sialyltransferase activity.


Affinity chromatography of serum albumin with fatty acids immobilized on agarose.


Configuration of 2-hydroxyputrescine.

Configuration of 2-hydroxyputrescine.


S-Adenosyl-L-methionine: loganic acid methyltransferase. A carboxyl-alkylating enzyme from Vinca rosea.


Intestinal epithelial cell surface membrane glycoprotein synthesis. II. Glycosyltransferases and endogenous acceptors of the undifferentiated cell surface membrane.


Inhibition of gluconeogenesis in the isolated perfused rat liver by  -phenylalkanoic acids.


Intestinal epithelial cell surface membrane glycoprotein synthesis. I. An indicator of cellular differentiation.


Purification and properties of the aldehyde oxidases from hog and rabbit livers.


The P-450 nature of the carbon monoxide complex of ferrous chloroperoxidase.


Plasma phosphate and potassium levels in the hypercalcemia of malignant disease.


Structure of the major glucosamine-containing ganglioside of human tissues.


Water-soluble products of the estrogens. Bile metabolites of 2-hydroxyestradiol-17beta in man.


Arginine vasotocin-like activity of cerebrospinal fluid in diabetes insipidus.


Steroid arteriovenous differences in umbilical cord plasma: evidence of cortisol production by the human fetus in early gestation.


Radioimmunoassay of prolactin in the urine of mouse and man.


Comparison of a biological and an immunological assay for the measurement of plasma renin activity.


Regulation of human gonadotropins. XIV. Gel filtration and electrophoretic analysis of endogenous and extracted immunoreactive human follicle-stimulating hormone of pituitary, serum and urinary origin.


Selective venous catheterization of the neck: localization of a parathyroid adenoma drained anomalously by nonthyroidal veins.


Attempts to prevent disuse osteoporosis by treatment with calcitonin, longitudinal compression and supplementary calcium and phosphate.


Lack of thyroid peroxidase activity as the cause of congenital goitrous hypothyroidism.


Evidence for a role of antidiuretic hormone (ADH) in the antidiuretic action of chlorpropamide.


Studies of the role of sex steroids in the feedback control of FSH concentrations in men. Studies on the role of sex steroids in the feedback control of follicle stimulating hormone (FSH) concentrations in 22-35 year old men are reported.  10 normal volunteers and 8 men undergoing evaluation for azoospermia or oligospermia received steroids by constant infusion for 96 hours at twice the estimated daily production rate of normal men to obtain stable levels in peripheral blood.  15 mg of testosterone increased plasma testosterone and estradiol levels 2-fold and suppressed FSH and luteinizing hormone (LH) approximately 40% during infusion Days 3 and 4.  90 mcg of estradiol/day caused similar suppression of FSH and LH and the addition of 4.5 mg of 17 alpha-hydroxyprogesterone had no additive effect.  7.5 mg of dihydrotestosterone/day produced no detectible changes in FSH or LH.  No evidence for a selective effect of any of the steroids on FSH secretion was seen.  These data support the concept that although there is a specific seminiferous tubular factor regulating FSH secretion, testicular steroids also modulate FSH secretion.


Effects of single and multiple pulses of arginine on insulin release in man.


Episodic variation in plasma corticosteroids in subjects with Cushing's syndrome of differing etiology.


Precocious puberty following treatment in a 6-year-old male with congenital adrenal hyperplasia: studies of serum luteinizing hormone (LH), serum follicle stimulating hormone (FSH) and plasma testosterone.


Quantitative measurement and significance of 5 plasma corticosteroids during the perinatal period.


Blood levels of gonadotropins and gonadal hormones in gynecomastia associated with chronic hemodialysis.


The effect of supine and lateral recumbency on plasma renin activity during pregnancy.


Delta-4-3-ketosteroid 5 alpha-reductase in the adult human testis.


Scanning and transmission electron microscopy of the human endometrial surface epithelium.


The interrelations of the striatum with subcortical areas through the lateral forebrain bundle.


Some morphological aspects of the integrating acticity of the cerebral cortex.


Comparative studies on oxygen consumption, electrolyte metabolism and ultrastructure of the isolated rabbit choroid plexus.


N-hexyl-O-glucosyl sphingosine, an inhibitor of glucosyl ceramide  -glucosidase. A synthetic analog of glucocerebroside, N-hexyl-O-glucosyl sphingosine, was found to inhibit the glucosidase in rat spleen that hydrolyzes glucocerebroside. At a concentration of 1 micro m, the analog inhibited the enzyme by 48%. The mode of action appeared to be competitive, probably aided by tight binding of the amine group to a carboxyl group near the enzyme's active site. Increasing or decreasing the chain length of the n-alkyl group attached to the nitrogen atom led to decreased effectiveness. The inhibitory effect was maximal at pH 7.0, but it was still considerable at the enzyme's optimal pH, 5.0. It is suggested that the compound may be useful for inducing an animal model of Gaucher's disease.


Use of the isolated perfused rat lung in studies on lung lipid metabolism. A procedure for the use of the isolated perfused rat lung in studies on metabolic regulation has been developed. The procedure, reasonably uncomplicated, yet physiological, maintains the lung so that edema is not observed. The phospholipid content remains normal, and incorporation of [1-(14)C]-palmitate, [2-(14)C]acetate, and [U-(14)C]glucose is linear with time for a minimum of 2 hr. The incorporation of [1-(14)C]-palmitate and [2-(14)C]acetate into the total lung phospholipid fraction and into the phosphatidylcholine and phospatidylethanolamine fractions has been studied. Increasing the concentration of palmitate in the medium from 0.14 to 0.51 mm increased by 60% the incorporation of [1-(14)C]palmitate into the total lung phospholipid fraction at 2 hr. When the palmitate concentration of the medium was 0.14 mm, addition of 0.11 and 0.79 mm oleate to the medium decreased [1-(14)C]palmitate incorporation into the total lung phospholipid fraction at 2 hr by 37 and 49%, respectively. The results suggest that the incorporation of exogenous fatty acids, present in the medium perfusing the lung, into lung phospholipids may depend upon the fatty acid composition of the medium. Known specific acyltransferase activities may be responsible for the ordered incorporation of available fatty acids into lung phospholipids.


Effect of CO 2  concentration on phospholipid metabolism in the isolated perfused rat lung. Studies have been carried out on the incorporation of [U-(14)C]glucose, [2-(14)C]pyruvate, [2-(14)C]acetate, and [1-(14)C]-palmitate into the phospholipids of the isolated perfused rat lung in the presence of either 6 or 45 mm total CO(2) concentration in the perfusion medium. Incorporation of [U-(14)C]glucose into total phospholipid and into the phosphatidylcholine fraction was increased 19-53% over the 2-hr perfusion period in lungs perfused with medium containing 45 as compared with 6 mm CO(2). The incorporation of [2-(14)C]acetate, [2-(14)C]-pyruvate, and [1-(14)C]palmitate was not affected by the change in medium CO(2) concentration. Increased incorporation of [U-(14)C]glucose combined with a shift toward greater incorporation into the fatty acids of the phosphatidylcholine fraction produced a maximum increase of 90% in [U-(14)C]glucose incorporation into the fatty acids of phosphatidylcholine after 2 hr of perfusion in the presence of medium containing 45 mm CO(2) as compared with 6 mm CO(2). The increase in medium CO(2) concentration produced as much as a 150% increase in [U-(14)C]glucose incorporation into palmitate derived from the phosphatidylcholine fraction. The results provide evidence that glucose functions as an important precursor of palmitate in the phosphatidylcholine fraction of lung phospholipids and that the CO(2) concentration of the perfusion medium affects the incorporation of glucose into palmitate.


Kinetic dependence of phospholipase A 2  activity on the detergent Triton X-100. A kinetic analysis is presented for the dependence of one form of phospholipase A(2) from cobra (Naja naja) venom on the presence of the nonionic detergent Triton X-100 for its activity towards egg phosphatidylcholine and synthetic dipalmitoyl glycerophosphorylcholine as substrates. An automatic recording pH-stat apparatus was employed in order to continuously monitor enzyme activity. The results obtained in this study are interpreted in terms of a change in the physical state of the phospholipid when Triton X-100 micelles convert phospholipid bilayers into mixed Triton X-100-phospholipid micelles; this is consistent with the requirement of this enzyme for substrates which are in micellar form rather than either monomers or bilayers. An apparent inhibition of phospholipase A(2) activity at high concentrations of Triton X-100 is described and discussed in terms of the micellar nature of the substrate.


Cellular and enzymatic changes in porcine adipose tissue during growth. Experiments were designed to define some of the cellular and metabolic changes in various areas of porcine adipose tissue during growth and to establish a relationship between these changes and the accumulation of fat in the domestic pig. 35 male castrate pigs were killed at various ages from late fetal to 6.5 months. The following determinations were made on each animal: (1) total carcass fat, (2) adipose cell size and number by fixation of adipose tissue with osmium tetroxide, and (3) the activities of acetyl CoA carboxylase, citrate cleavage enzyme, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and malic enzyme from perirenal adipose tissue and each of the three layers of subcutaneous backfat. Carcass adipose tissue expanded by a combination of adipocyte hyperplasia and hypertrophy up to 5 months, after which adipose expansion was accomplished by cellular hypertrophy only, with no significant increase in cell number. The activities of the selected lipogenic enzymes (expressed on an adipose cell basis) increased markedly at weaning and again during the rapid increase in percentage of body fat between 3.5 and 5 months. Enzyme activities reached a peak at 5 months, after which activities decreased to values approaching mature levels.


Effect of dietary fat on pancreatic lipase levels in the rat. The effect of dietary fat on levels of lipase and other enzymes in rat pancreas has been studied. It was possible to raise levels of lipase in animals by supplementing their commercial chow diet with added fat or by raising the level of fat in semipurified diets from 4% to 22%. Pancreatic amylase levels decreased in rats fed the high fat diets, whereas levels of chymotrypsinogen and trypsinogen were unaffected. The type of carbohydrate in the semipurified diets made no difference. Thus, the levels of enzymes in rats fed dextrose-containing diets or cornstarch-containing diets were similar. On the basis of the present data, and results of others, it would appear that levels of pancreatic lipase are increased when the fat content of the diet is raised from about 5% to 15-22%, but that little or no additional increase in lipase levels can be attained by any further increase in the amount of dietary fat.


Three-pool model of the long-term turnover of plasma cholesterol in man. The long-term turnover of plasma cholesterol was examined in six men injected intravenously with [4-(14)C]cholesterol. The specific radioactivity-time curves were determined for periods of 32-41 wk and were analyzed by computer according to a two-pool and to a three-pool model. In each subject, the three-pool model provided a significantly better description of the long-term turnover curve than did the two-pool model. No further improvement in fit between observed and computed curves was obtained with a four-pool model. The results indicate that the turnover curves of all six subjects conformed to, and could be satisfactorily described by, a three-pool model, as expressed by the equation: specific activity = A(1)e(-alpha(1)t) + A(2)e(-alpha(2)t) + A(3)e(-alpha(3)t). The assumption was made that exit of cholesterol from the body occurs only by way of the tissue pools which comprise the rapidly exchangeable compartment, pool 1. With this assumption, the production rate in pool 1 (PR) is equivalent to the total body turnover rate. The parameters of the three-pool model which can be calculated include PR, the size of pool 1 (M(1)), and the rate constants for transfer between pools. Unique values cannot be obtained for the sizes of the more slowly exchangeable pools of body cholesterol, but their upper and lower limiting values can be determined. The observed values for PR and M(1) (means +/- sem) were 1.13 +/- 0.09 g/day and 23.4 +/- 1.1 g, respectively. When only the first 12 wk of data were analyzed, the turnover curves in all subjects conformed to the two-pool model. The results so obtained were compared with those obtained with the long-term data. The medium-term data provided a valid estimate for M(1), a slightly (8-9%) elevated value for PR, and a quantitatively unreliable (low) estimate of total exchangeable body cholesterol, as compared with the long-term data. Previous estimates of the production rate from studies of 10-12 wk duration can be considered valid if reduced by 8-9%.


Improved estimation of body masses and turnover of cholesterol by computerized input--output analysis. In 23 patients, the decay curves of serum cholesterol specific activity after a single intravenous dose of radioactive cholesterol were measured for 16-66 wk and were subjected to computerized input-output analysis. Of 17 patients with decay curves followed for longer than 50 wk, a three-exponential curve fit was better in 12, and a two-exponential curve fit in 5, according to computerized F tests. Of six patients with decay curves followed for less than 50 wk, a two-exponential curve fit was better in five and a three-exponential curve fit in one. In the 13 patients who exhibited three-exponential curve fits, the third exponential appeared after 13-43 wk of observation (average, 25 wk). In 12 patients of this group who were followed for 50 wk or more, turnover rates and exchangeable masses of cholesterol were measured at maximum lengths of the curves (50-66 wk), and these parameters were then compared with measurements made with curves successively shortened down to 10-12 wk. The average differences between analyses of the minimum vs. the maximum lengths of the curves were: It (input rate: absorbed dietary plus biosynthesized cholesterol), 14% larger (1.24 vs. 1.09 g/day); M(a) (rapidly exchangeable mass of cholesterol), no change (34 vs. 33 g); M (total exchangeable mass), 26% smaller (67 vs. 91 g); M - M(a) (remaining exchangeable mass), 39% smaller (40 vs. 65 g). Significant differences in It, M, and M - M(a) (minimum vs. maximum curve lengths) were found in both normolipidemic and hypercholesterolemic patients, and the differences were of similar magnitude in the two groups. Since only 12 of 17 patients followed for 50 wk or longer demonstrated three-exponential curve fits, various means were sought by which it might be predicted at the outset whether a given patient must be studied for so long a time; none was found. However, in the group with two exponentials the value of M(a) was significantly larger than those with three-exponential curve fits, and this difference was apparent at as early as 10-12 wk.


Metabolism of palmitic acid in the subcellular fractions of mouse brain. After an intracerebral injection of [(14)C]palmitic acid to C57BL/10J mice, the radioactivity in the brains decreased rapidly with time. The incorporated radioactivity was primarily in the 16:0 acyl groups of the diacyl phosphoglycerides at 1 and 3 days after injection. At longer times, increasing proportions of the radioactivity were found in cerebrosides, alkenyl groups, and other acyl groups. The specific radioactivities of the phosphoglycerides were highest in the microsomal fraction at 1 day after injection. The exchange of the diacyl glycerophosphorylcholines and diacyl glycerophosphorylethanolamines between the microsomes and the myelin required 8-14 days. When calculated on the basis of the radioactivity in the 16:0 acyl groups, the half-lives for both of these phosphoglycerides were 6-8 days in all subcellular fractions during the period from 14 to 30 days after injection. The radioactivity in the total lipids from the purified myelin fraction did not decline until more than 14 days after injection because of the reutilization of labeled 16:0 acyl groups for lipid biosynthesis. Recycling of the acyl groups explains the long half-lives reported for myelin phosphoglycerides after injection of [(14)C]acetic acid. Lipids with a relatively high specific radioactivity were lost from the myelin fraction during the purification procedure. The most likely source of these lipids is the most recently formed myelin that is not consolidated into the myelin sheath.


Quantitative analysis of unconjugated and conjugated bile acids in duodenal fluid by densitometry after paper electrophoresis. A new paper electrophoretic method for the separation of bile acids into five groups, (1) unconjugated, (2) glycine conjugates and (3) taurine conjugates, and (4) and (5) the respective monosulfates, is described. Rapid and accurate qualitative and quantitative estimations of each group are obtained by densitometry after internal standardization and phosphomolybdate color development. The technique can be done in the routine clinical laboratory and is useful for the detection of diseases affecting the enterohepatic circulation of bile acids.


Effects of acidic phospholipids, nucleotides, and heparin on the activity of lipase from rat liver lysosomes. Purification and characterization of endogenous lipid factors that stimulate rat liver lysosomal lipase has led to the identification of cardiolipin, phosphatidylserine, and phosphatidic acid as stimulators of this activity. Bovine heart cardiolipin (half-maximal stimulation at 1.5 x 10(-4) m) and bovine brain phosphatidylserine (half-maximal stimulation at 9.5 x 10(-4) m) were the most potent of the phospholipids from other sources tested. The major rate-enhancing effect of phosphatidylserine is expressed as a 35-fold increase in the apparent V(max) of the enzyme. The effect is produced by acid phospholipids specifically, since in no case was there greater than a twofold stimulation by synthetic detergents, zwitterionic phospholipids, taurocholic acid, or gum acacia. The observed degree of stimulation depends upon the detergent used to disperse tripalmitin substrate and the relative concentrations of factor and detergent in reaction mixtures. The concentration of phosphatidylserine to produce half-maximal stimulation is directly dependent upon the Triton X-100 concentration, but the effects of this detergent on cardiolipin stimulation are more complex. Enzyme activity is inhibited 50% by 1 mm nucleoside triphosphate and 2.5 mm ADP, 80% by 1 mm PP(i), 100% by 20 U/ml heparin and 0.25 mg/ml chondroitin sulfate, and 80% by 10 mm sulfate ion. Inhibition is partially prevented by phosphatidylserine.


Nonstainable polyester film, Cronar, for electrophoresis of plasma lipoproteins. The Photo Products Department of E. I. du Pont de Nemours has recently made available a new type of polyester film, Cronar, for use in the electrophoretic separation of plasma lipoproteins. This film does not take up lipid dyes. There is no background color. The film remains clear and transparent after staining for lipoproteins.


Lipid composition of plant mitochondria and of chloroplasts. The mitochondrial lipids from avocado fruit, cauliflower buds, and potato tubers, and the lipids of chloroplasts isolated from avocado fruit and from cauliflower leaves were identified and the concentrations were determined. The lipid composition was compared with that of beef heart mitochondria. Phospholipids constituted 50-56% of total lipids in plant mitochondria while this fraction made up 90% of the lipids in beef heart mitochondria. In both cases the chief phospholipids were phosphatidylcholine and phosphatidylethanolamine. A characteristic feature of plant mitochondria was the presence of monogalactosyl- and digalactosyldiglyceride and of sulfolipid. Potato mitochondria differed from the particles of other species investigated by their higher content of galactolipids, sterol glycosides, and carotenoids and lower content of phospholipids and of total lipids in the lipidprotein complex. The galactolipid content was markedly higher in chloroplasts from all sources than in mitochondria. The spectrum of lipids in the phospholipid fraction differed more strikingly between chloroplasts of the leaf and the mitochondria of the bud of cauliflower than between the two organelles of the avocado mesocarp. The fatty acid distribution of individual lipids and of classes of lipids was also more similar in the two organelles of the fruit tissue than in the cauliflower material.


Distribution of alamethicin in lipid membranes and water. The concentration of alamethicin in aqueous solutions was quantitated using measurements of the spot area on thin-layer chromatograms. These data were utilized to measure a partition coefficient of 17 for alamethicin in a phospholipid membrane-water system under equilibrium dialysis conditions.


Quantitative extraction and determination of nonesterified fatty acids in plasma. A method is described for the determination of nonesterified fatty acids in plasma. Extraction is at least 98% efficient, and losses during subsequent stages are corrected for by the use of an internal radioactive standard. The method is suitable for reference purposes rather than for routine determinations. Higher values are obtained than by other methods of analysis, and it is suggested that some plasma fatty acids remain protein-bound after normal methods of extraction.


TB talk 1973.

TB talk 1973.


Bold new programs fill 'Country Doctor' role.


Nonfatal accidental organophosphate pesticide intoxication in seven inmates of a correctional institution.


A uniform ambulance reporting form.

A uniform ambulance reporting form.


The patterns of arylsulphatases A and B in human normal and metachromatic leucodystrophy tissues and their relationship to the cerebroside sulphatase activity.


Kinetics of choline acetyltransferases (EC 2.3.1.6) from human and other mammalian central and peripheral nervous tissues.


Pyruvate metabolism by homogenates of human brain: effects of phenylpyruvate and implications for the etiology of the mental retardation in phenylketonuria.


GABA uptake in rat brain slices: inhibition by GABA analogues and by various drugs.


The use of microwave heating to inactivate cholinesterase in the rat brain prior to analysis for acetylcholine.


Effects of added substances on RNA and protein synthesis in immature neurons.


The role of GABA metabolism in the convulsant and anticonvulsant actions of aminooxyacetic acid.


Transaminations between amino acids and keto acids elevated in phenylketonuria and maple syrup urine disease.


Level and amino acid acceptor activity of mouse brain tRNA during neural development.


The effects of undernutrition on the proteins of optic and sciatic nerves during development.


Recovery from galactose-induced neurotoxicity in the chick by the administration of glucose.


Subcellular fractionation of postmortem brain.


Carbohydrate metabolism in brain during convulsions and its modification by phenobarbitone.


Effects of amino-oxyacetic acid on ( 3 H)GABA uptake by rat brain slices.


Incorporation of ( 14 C)choline into phospholipids in the isolated phrenic nerve-diaphragm preparation of the rat.


The uptake of  -( 3 H)aminobutyric acid by slices from various regions of rat brain and the effect of lithium.


Arylsulphatase A (EC 3.1.6.1) activity in rat central nervous system during experimental allergic encephalomyelitis.


Accelerated postnatal development of D(-)- -hydroxybutyrate dehydrogenase (EC 1.1.1.30) activity in the brain in hyperthyroidism.


High affinity uptake of transmitters: studies on the uptake of L-aspartate, GABA, L-glutamate and glycine in cat spinal cord.


3-Methoxy-4-hydroxyphenylethanol in the rat brain.


Glycogen and glycogen phosphorylase in the cerebral cortex of mice under the influence of methionine sulphoximine.


Choline: selective accumulation by central cholinergic neurons.


The accumulation of radioactive acetylcholine by a sympathetic ganglion and by brain: failure to label endogenous stores.


Alkylation of rat brain nucleic acids by N-methyl-N-nitrosourea and methyl methanesulphonate.


Intracellular distribution of DNA polymerase activities in developing and adult rat brain.


Elongation of fatty acids in human brain tissue.


Permanent alterations in 5-hydroxyindole concentrations in discrete areas of rat brain produced by the pre- and neonatal administration of methylamphetamine and chlorpromazine.


The actions of the dimethyl and diethyl esters of glutamic acid on glutamate uptake by brain tissue.


Metabolism of acetate and N-acetylaspartate in isolated perfused rat brain.


Infantile type of so-called neuronal ceroid-lipofuscinosis. 1. A clinical study of 15 patients.


Late onset mitochondrial myopathy.

Late onset mitochondrial myopathy.


The uptake of hemicholinium-3 by rat brain cortex slices.


Effect of 3,4-dihydroxyphenylacetic acid on catecholamines and serotonin in rat striatum.


Lateral inferior pontine syndrome. Clinico-pathologic study and review of literature.


The influence of salt-free solutions on cold-induced cerebral oedema. A chemical and morphological study in the rat.


Tissue acetylcholinesterase in plasma of chick embryos and dystrophic chickens.


Relationships between rate and pattern of unitary discharges in medial geniculate body of the cat in response to click and amplitude-modulated white-noise stimulation.


The incidence of lobulated fibres in the facioscapulo-humeral type of muscular dystrophy and the limb-girdle syndrome.


Conduction velocity in pathways from retina to superior colliculus in the cat: a correlation with receptive-field properties.


Membrane-potential trajectories underlying motoneuron rhythmic firing at high rates.


Discharge patterns of soleus motor units with associated changes in force exerted by foot during quiet stance in man.


Receptor categories represented in spinal trigeminal nucleus caudalis.


Unit activity in brain stem reticular formation of the rat during learning.


Proximal negative response and retinal sensitivity in the mudpuppy, Necturus maculosus.


Radionuclide angiography in the diagnosis of cerebrovascular disease.


Projection of X- and Y-cells of the cat's lateral geniculate nucleus to areas 17 and 18 of visual cortex.


Kit for carrier-free  123 I-sodium iodide. 8.


Evaluation of myocardial perfusion after intracoronary injection of radiopotassium.


Subdural hematoma--what is the role of brain scanning in its diagnosis?


Measurement of serum thyroxine by the Tetralute procedure: the effect of  131 I and  99m Tc administration.


Rapid sequential scintiphotography in the radionuclide detection of subdural hematomas.


Brain scan in Schilder's disease.

Brain scan in Schilder's disease.


Uptake of  87m Sr by liver metastasis from carcinoma of colon.


Scintiphotographic diagnosis of abruptio placentae.


131 I-triolein absorption test.

131 I-triolein absorption test.


Whole-body immobilizer.

Whole-body immobilizer.


Cross circulation between children in hepatic coma and chimpanzees. Clinical, biochemical, and coagulation observations.


A controlled prospective study of cyclophosphamide in relapsing, corticosteroid-responsive, minimal-lesion nephrotic syndrome in childhood.


Therapeutic and toxic effects observed with different dosage programs of cyclophosphamide in treatment of steroid-responsive but frequently relapsing nephrotic syndrome.


Hypoplasia of the anterior pituitary and neonatal hypoglycemia.


Ornithine transcarbamylase deficiency in the newborn infant.


Demonstration of cholinergic cells in human neuroblastoma and ganglioneuroma.


Periotoneal fluid in necrotizing enterocolitis: a radiologic sign of clinical deterioration.


Exposure to quinine and jaundice in a glucose-6-phosphate dehydrogenase-deficient newborn infant.


Clinical pharmacology of penicillin in newborn infants.


Hypoplastic anemia.

Hypoplastic anemia.


Rapid, "painless" local anesthesia.

Rapid, "painless" local anesthesia.


Disseminated aspergillosis during treatment of hepatic failure.


Decrease in spleen size in thalassemia major.


Microangiographic study in experimentally produced megaureter in rabbits.


Some aspects of renal function in the newly born.


Reconstruction of previously diverted urinary tracts in children.


Urologic abnormalities associated with imperforate anus.


Intrauterine production of coarctation of the aorta with normal birth and survival.


The effect of gastric resections and denervation upon growth in miniature swine.


Massive small-bowel resection in an infant: long-term management and intestinal adaptation.


Adrenergic hyperactivity of the aganglionic colon.


Inside tracheoesophageal fistula: new endoscopic approaches.


Clinical evaluation of the fiberoptic bronchoscope (Olympus BF 5B) for pediatric endoscopy.


Excessive morbidity resulting from the prevention of intestinal adhesions with steroids and antihistamines.


Varicose veins following ankle cutdowns.


A critical look at the Soave procedure for Hirschsprung's disease.


Pulmonary xanthomatous postinflammatory pseudotumors in children.


An approach to acquired coagulation problems in the neonatal surgical patient.


Acute appendicitis in the first two years of life.


Choledochal cysts: diagnostic and therapeutic problems.


Replacement of entire right atrial wall in an infant with a cardiac rhabdomyoma.


Hirschsprung's disease: long-term results of resection of the proximal dilated segment.


Agenesis of the penis.

Agenesis of the penis.


Incarcerated "Foramen of Winslow" hernia in a newborn.


Leiomyoma of omentum.

Leiomyoma of omentum.


Use of the appendix as a colon substitute in vesicointestinal exstrophy.


Blood-filled cysts on heart valves.

Blood-filled cysts on heart valves.


Segmental dilation of the jejunum.

Segmental dilation of the jejunum.


The differential diagnosis of seizures.

The differential diagnosis of seizures.


Medical aspects of subarachnoid haemorrhage.


The pathology of subarachnoid haemorrhage.


Surgical management of subarachnoid haemorrhage.


A study of pharyngeal speech.

A study of pharyngeal speech.


The "silent cough" method for vocal hyperfunction.


A lexical approach to the remediation of final sound omissions.


The development of language-training programs for postrubella hearing-impaired children.


Modification of lip hypertonia in dysarthria using EMG feedback.


A phonological analysis of the spontaneous language of a four-year-old, hard-of-hearing child.


Regularities in abnormal child phonology.


The Denver articulation screening exam.

The Denver articulation screening exam.


A pilot training program for parent-clinicians.


The nonverbal child: some clinical guidelines.


Communication boards for cerebral-palsied children.


Velopharyngeal function: some important differences.


Detection of thymidine-phosphorylase in human blood platelets.


Pressure vessel for liquid filtration.

Pressure vessel for liquid filtration.


Convenient dialysis assembly.

Convenient dialysis assembly.


Technique for chromosome band densitometry.


Thin layer gel filtration: principles and applications.


Klippel-Feil syndrome.

Klippel-Feil syndrome.


Femoral neck fractures. Analysis of hip prosthetic replacements.


The sugartong splint.

The sugartong splint.


Recurrent hemangioma of the hand.

Recurrent hemangioma of the hand.


Acute ligamentous injuries of the knee joint.


Diabetic foot problems: pathogenesis.

Diabetic foot problems: pathogenesis.


Femoral shaft fractures in children.

Femoral shaft fractures in children.


Scapulo-thoracic fusion.

Scapulo-thoracic fusion.


Distal humerus fractures.

Distal humerus fractures.


Operation on demand?

Operation on demand?


The people problem.

The people problem.


Research in family medicine.

Research in family medicine.


Pulmonary aspects of myocardial infarction.


Possible involvement of a dopaminergic pathway in the depressant effe ts of ouabain on the central nervous system.


Brain concentrations and synthesis rates of biogenic amines during chronic cobalt experimental epilepsy in the rat.


Structure-activity relationships of intracerebrally injected tremorigenic indole alkaloids.


Vinblastine and vincristine: a study of their action on tissue concentrations of epinephrine, norephinephrine and acetylcholine.


Differential effects produced by delta 1 -tetrahydrocannabinol on lateral geniculate neurones.


Effect of butyrophenones on motor function in rats after recovery from brain damage.


Increased trihydroxycoprostanic acid in bile in familial intrahepatic biliary atresia.


The medicolegal screening panel. An evaluation of Montana's experience.


A Northwest general practice. Search and survey--methods and results.


Quinidine toxicity: a review.

Quinidine toxicity: a review.


Surgery of the facial nerve.

Surgery of the facial nerve.


Reye's syndrome: report of a case.

Reye's syndrome: report of a case.


Abdominal pain following acute myocardial infarction.


Pericardial tumors: a useful technic for diagnosis.


Femoral fracture in the newborn.

Femoral fracture in the newborn.


Hemodynamic effects of isoproterenol and noradrenalin in experimental shock.


Fibrinolysis in human malignant tumours.


The mineral phase of experimental heterotopic osteogenesis in the ischemic rat kidney as shown by the calcium distribution.


Studies in fat necrosis. II. Early ultrastructural changes in rat adipose tissue during experimentally induced pancreatitis.


Studies in fat necrosis. IIa. Plasma lipids in acute experimental pancreatitis in rats.


Healing and adhesion formation of peritoneal wounds. An angio-, histoangiographic, and ultrastructural study.


The natural history of primary and secondary malignant tumours of the liver. IV. The prognosis for patients with carcinoma of the gallbladder, with special reference to the amount of tumour growth within the liver at the time of diagnosis.


The absorption of an amino acid (L-methionine) in isolated, homologously perfused small intestine.


Morphological and fluorescence-histochemical studies on isolated, homologously perfused small intestine.


Investigation and analysis of the position, fixation, length and embryology of the vermiform appendix.


Repair of preduodenal portal vein injury occurring during biliary surgery.


A case of renal artery thrombosis following blunt trauma.


Effect on respiration of changes in the form of the naturally occurring oscillation in arterial pH. We have previously shorn that the respiratory control system in the cat has the requisite sensitivity and speed to respond to changes in arterial pH which are equal to, or smaller than, the normal fluctuations in pH with respiration. A respiratory response was only observed when the changes in pH were produced by alterations in PCO2 and not when they were induced by non-gaseous acids. We describe now the respiratory effect produced by various procedures which modify or abolish the naturally occurring arterial pH oscillations before they reach the peripheral chemoreceptors. The pH oscillations were abolished by a mixing chamber, whilst their phase relationship to respiration was altered by delay coils; by presenting a moving plastic surface to the arterial blood stream it was possible to distort the shape of the oscillations without increasing the transport lag between lung and peripheral chemoreceptors. All manoeuvres produced a brief period of respiratory stimulation which was greater than could occur by chance. We were particularly concerned in these experiments with the possibility of artefacts in our experimental design. We feel that we have excluded respiratory effects due to changes in arterial pressure, blood temperature and mean pH. We are less confident that we have excluded changes in ventilation resulting from the release of a substance (or substances) from the contact of blood with plastic or glass surfaces. This problem is discussed in relation to experiments on the control of breathing where blood, which is perfusing the chemoreceptors, has been in contact with artificial surfaces.


The effects of various time patterns of alveolar CO 2  and O 2  on breathing in man. We have studied the responses of human arterial chemoreceptors to various patterns of quick change of stimulation. (i) Transient abolition of hypercapnia lowers VE after 2 breaths (chemoreceptor latency) only if PAO2 is low, therefore hypoxia is necessary for an arterial chemoreceptor response to CO2. (ii) Alternate breaths of euoxia and hypoxia, and of eucapnia and hypercapnia, separately and combined, have no special effect on mean V. However, oscillating CO2 commonly causes breath-by-breath alternation of V, but only if hypoxia is present; oscillating only the low O2 seldom causes oscillation of V. Concluded (a) that chemoreceptor responses to delta-CO2 are quicker than to delta-O2; (b) that, above CO2 threshold, response to rising CO2 is equal and opposite to response to falling CO2. (iii) Three time patterns of PACO2 within single respiratory cycles have been compared in hypoxia. At a single mean arterial PCO2, a small sharp fall of PACO2 early in inspiration depresses mean V, while a smaller sharp fall of PACO2 late in inspiration increases mean V. Concluded that human respiratory system distinguishes between these rather similar patterns presumably through arterial chemoreceptor pathway since the phenomenon depends on the presence of hypoxia. The importance of exact timing is emphasised.


'Specific' and 'non-specific' stimuli in the drive of respiration. In decerebrate and awake cats it was shown that central chemosensitivity can be blocked by cooling or coagulating bilaterally a formerly described area on the ventral medullary surface of cats, called area S. Such a procedure is followed by apnoea under the condition that vagi and sinus nerves are cut. With either vagi, sinus nerves, or central chemosensitivity intact respiration can be influenced by noise, touch, and electrical stimulation of dorsal roots, femoral nerves, and pontine reticular formation. With vagi, sinus nerves, and central chemosensitivity blocked, these "non-specific" stimuli are not able to influence respiration. In the described experiments vagi, sinus nerves, and central chemosensitivity were essential for the activity of the respiratory centres and were therefore called "specific".


The influence of body temperature on the ventilatory response to CO 2  in anaesthetized rats. The breathing frequency, tidal volume and partial pressure of CO2 in arterial blood (PaCO2) were measured continuously in urethan anaesthetized rats at different body temperatures. In urethan anaesthesia the colonic temperature of our rats averaged 33.5 plus or minus 1.29 degree Celsius, when the ambient temperature was 22-24 degree Celsius. At this temperature their PaCO2 was the highest, 42 plus or minus 1.2 mm Hg on the average. With decreasing or increasing body temperature the PaCO2 declined. The breathing frequency increased with increasing body temperature. The ventilatory CO2 response curve in warmed rats was shifted towards higher ventilation. Its relative slope was parallel, in absolute units it was steeper than that of the cooled animals. After vagotomy the rate of breathing averaged 42-48 percent of the control values, at all body temperatures. The calculated inspirio-inhibitory index (V/VT) shows a relatively identical decrease (37-39 percent) after vagotomy in warmed, same as in cooled rats. The results indicate that in urethan anaesthetized rats the sensitivity to CO2 remains the same in the range of body temperatures from 28 to 38 degree Celsius. Also the relative role of the vagus nerves does not change within the range of these temperatures.


The significance of the timing of chemoreceptor impulses for their effect upon respiration. Alveolar partial pressure of carbon dioxide (PACO2) and alveolar partial pressure of oxygen (PAO2) oscillate at the frequency of respiration and the oscillations persist into the arterial blood as oscillations of arterial partial pressure of carbon dioxide (PaCO2) and arterial partial pressure of oxygen (PaO2). Arterial chemoreceptors respond quickly enough to changes in PaCO2 and PaO2 for the arterial oscillations to give rise to oscillations in their afferent discharge at the frequency of respiration. The respiratory centre responds with short latency to afferent impulses reaching it. If a burst of impulses reaches it during an inspiration, the depth of that inspiration, is increased but if the burst arrives during expiration, the succeeding inspiration is little affected. Thus if the peaks of chemoreceptor afferent discharge coincide with inspiration, they have a greater effect on respiration than if they coincide with expiration. The phase relation between the activity of the respiratory centre and the oscillations it produces is determined, inter alia, by the frequency of respiration and the heart output. Thus it may well change in exercise.


Mechanism of excitation of type J receptors. The type J receptors are stimulated during pulmonary congestion produced by occluding the aorta or left a-v junction which causes the left atrial pressure to rise with consequent rise in pulmonary artery pressure. Such acute congestion can be maintained only for brief periods (1-2 min). Longer lasting congestion leading eventually to pulmonary oedema is produced by injecting alloxan into the right atrium or right ventricle. A marked rise in pulmonary artery pressure follows the injection and after a lag there follows intense excitation of the type J receptors. It was concluded that this excitation was due to a rise in pulmonary capillary pressure and increase in permeability of the capillary membrane. Recent experiments have revealed that a considerable increase in activity can also be produced by injecting plastic microemboli (diameter 50 minus-plus 10 micrometers, i.v.). This increase occurs a few minutes after the rise in pulmonary artery pressure and is not due to a direct action of the microemboli on the endings nor can it be due to increased capillary permeability. Here, there can be no doubt that the increase in activity is a consequence of the rise in pulmonary artery pressure leading to a rise in pulmonary capillary pressure. This causes increase in interstitial volume leading to excitation of the endings. It was postulated that the endings were located in collagen tissue which acts like a sponge. Recently electronmicroscopic evidence has been obtained showing the presence of non-medullated sensory fibres in this collagen tissue but the precise structure of the endings (presumably type J) and their physical relation to the collagen tissue still remains to be established.


Analyses of breath-by-breath responses of ventilation to CO 2  employing V-PCO 2  loops. Computer techniques were employed to construct a respiratory control model in which the variables treated were programmed according to a series of mathematical equations, with the purpose of eliciting the relationship of V-PCO2 (minute ventilation-partial pressure of carbon dioxide) on a transient time basis. It was discovered that the transient V-PCO2 relationship has the shape of a loop half of which is for on-CO2 and the other half for off-CO2. Breath-by-breath ventilation was calculated by means of a home-made computer and the V-PCO2 relationship was monitored on an XY plotter. The transient V-PCO2 course also showed a loop which was quite similar in the general shape to the one traced employing theoretical analysis with an analog computer. This V-PCO2 loop may have potential usefulness to reveal mechanisms of respiratory control which may not be shown by the conventional V-PCO2 response curves.


Synchronization of discharge, spontaneous and evoked, between inspiratory neurons. (i) In midcollicular decerebrate, unanaesthetized, vagotomized, paralyzed cats, efferent phrenic discharge was recorded simultaneously with inspiratory unit and inspiratory wave activity in the rostral lateral medulla. Phrenic motoneurons tend to fire in synchronous bursts, as indicated by the occurrence of high frequency oscillation (60-110 per second; median oscillation period 13 ms) in the wholenerve recording. (ii) Crosscorrelation analysis of medullary inspiratory unit vs. phrenic activity showed that most units in the rostral medulla had oscillation of discharge which was locked to phrenic oscillation; peak unit activity usually occurred 3-5 ms before peak phrenic activity. Since this delay is comparable to the latency of a phrenic response evoked by an electric stimulus in the inspiratory regions, it is suggested that these medullary inspiratory neurons are part of the efferent inspiratory pathway from medulla to spinal cord. (iii) In the region near the nucleus ambiguus, wave activity occurring during the inspiratory phase was recorded; its phase relation to phrenic oscillation was similar to the unit-to-phrenic phase relation. It is suggested that the wave activity reflects synchronized synaptic potentials in neighbouring structures. (iv) By electrical stimulation of the rostral pontine pneumotaxic system (nucleus parabrachialis), it was possible to force the oscillation frequency as well as to change the phase relations of activity. (v) Thus, medullary inspiratory activity has a short-term synchrony. It is suggested that this synchrony arises from: (a) reexcitant connections between inspiratory neurons; (b) similar time courses of post-spike inexcitability in different inspiratory neurons. The phenomenon of high-frequency oscillation in inspiratory discharge furnishes an electrical sign of inspiratory activity, which should prove useful in analysis of the mechanisms producing inspiratory discharge.


Neuronal organization of the central respiratory mechanisms in the brain stem of the cat. In order to obtain basic evidence on the neuronal organization and localization of the central respiratory mechanism in the brain stem of the cat, the following experiments were undertaken: reexamination of the physiological meaning of apneusis and the gasp; differences in stability of spontaneous burst activity of respiratory neurons in the brain stem reticular formation; changes of spontaneous firing pattern of bulbar respiratory neurons in the isolated brain stem of the cat; changes of firing pattern of a pontine and a bulbar respiratory neuron during continuous recording of both unitary activities after brain stem transection at the pontomedullary junction; responses of respiratory neurons to electrical stimulation of the spinal cord; responses of respiratory neurons to electrical stimulation of the central cut end of the vagus nerve; effects of pentobarbitone on unitary activity of pontine and bulbar respiratory neurons. Based on the experimental result a preliminary scheme of a neuronal network of the central respiratory mechanism consisting of four subsystems of respiratory neurons: a primary neuron system; a satellite neuron system; an input neuron system; an output neuron system.


Relative roles of irritant, type-J and pulmonary stretch receptors in lung reflexes. Bilateral anodal block of both cervical vagus nerves of anaesthetized rabbits has been used to assess the relative role of afferent pathways with myelinated fibres (primarily from lung irritant receptors) and with nonmyelinated fibres (from J-receptors) in respiratory responses to some lung conditions. With inhalation of histamine aerosol the increase in breathing frequency is due to myelinated afferent fibres from irritant receptors. The similar response with inhalation of halothane is due to non-myelinated fibres from J-receptors. The reflex breathing response in lung oedema involves both pathways, but in the experimental conditions the myelinated pathway plays the larger part. The interaction of these two mechanisms, and the possible role of pulmonary stretch receptors, is discussed.


Responses of respiratory neurons of the rabbit to some excitatory and inhibitory stimuli. The effects of an afferent stimulation of the vagus nerve, hypercapnia and hyperventilation on the discharges of pontine, medullary and phrenic respiratory neurons were studied. The responses were investigated in spontaneously breathing, lightly anaesthetized rabbits with intact vagi, and subsequently during artificial ventilation, after vagotomy and under surgical anaesthesia. We found that the patterns of activity of respiratory neurons depend upon the integrity of vagal conduction, pattern of ventilation and depth of anaesthesia, and that vagotomy and deep anaesthesia markedly modify, and sometimes even reverse, the responses of these neurons to respiratory stimuli. The pre-vagotomy type of response can be restored by stimulating the central end of a cut vagus nerve with standard pulses triggered by action potentials recorded simultaneously from the animal respiratory unit. The significance of these findings is discussed.


Distribution of respiratory modulated units in the pons.


Organization of the pneumotaxic oscillator in the cat. The present series concerns the topographical organization of pneumotaxic neurons within the nucleus parabrachialis medialis and adjacent structures according to their respiratory subtype. Results presented were obtained from 1000 units recorded in a region 2.5 mm in height, 1.5 mm in width and 2.5 mm in length. During penetration in the postero-lateral part (mainly in Kolliker-Fuse nucleus) inspiration related cells were found almost exclusively. Phase-spanning inspiratory-expiratory neurons largely predominated in the central core of nucleus parabrachialis medialis. A large majority of expiratory cells was recorded at the antero-medial border of the nucleus. In the intervening regions, clusters of 6 to 10 cells of the inspiratory-expiratory (IE) type alternated with similar clusters of either inspiratory- or expiratory neurons. Phase-spanning expiratory-inspiratory (EI) neurons were mainly found in the intermediary positions between phase-spanning IE and either inspiratory or expiratory columns. A two dimensional reconstruction of pneumotaxic organization is presented and a tentative model of the oscillator is advanced.


The foetal and neonatal respiratory centre: focal stimulation and influence of anaesthesia.


Anatomical and functional heterogeneity of the medullary respiratory neurons. In a systematic study we attempted to activate the respiratory neurons antidromically by stimulating the spinal cord and the vagus. This has led to an anatomical and functional classification of the neurons: bulb-spinal neurons whose axons enter the spinal cord, vagal motoneurons, propriobulbar neurons which cannot be activated antidromically. We used simultaneously other tests (localization, response to Hering-Breuer reflexes or to cortical stimulation) which gave positive results. Two groups of respiratory neurons were apparent: a dorsal respiratory nucleus with only inspiratory bulbo-spinal neurons and a ventral respiratory nucleus with inspiratory and expiratory bulbo-spinal neurons, vagal motoneurons and propriobulbar neurons. The bulbo-spinal neurons and some propriobulbar neurons are normally related to Hering-Breuer reflexes evoked by lung inflation or deflation, but the recurrent laryngeal motoneurons or fibres and some propriobulbar neurons can give a paradoxical response to lung inflation. By cortical stimulation the propriobulbar neurons show only an arrest of their discharge, whereas the bulbo-spinal neurons give a burst of spikes followed by an inhibition. These results led to the following conclusions: (i) the propriobulbar neurons do exist; (ii) some neurons classified as medullary respiratory neurons have not really a ventilatory function: they belong to the laryngeal system; (iii) it is fundamental to use systematically the antidromic test and some other ones to know exactly the hodological situation of the neurons in the respiratory complex.


Regulation of respiration by bronchopulmonary receptors in conscious dogs. In awake dogs, the Hering-Breuer inflation reflex (HBIR) was present but weaker than during anaesthesia. Auditory or visual distraction, increased body temperature, and exercise decreased or abolished HBIR. Bilateral complete vagal blockade resulted in slow deep breathing, but arterial PCO2, and apnoeic threshold PCO2, were unafected. Vagal blockade decreased the response of frequency of respiration during hypoxemia and hypercapnia, but did not affect the response to increasing body temperature or to exercise. Progressive cooling of the exteriorized vagal loops from 16 to 9 degrees Celsius resulted in progressive abolition of HBIR, but the respiratory response to inhaled histamine was unaffected. There was a decrease in the expiratory phase of respiration and in tidal volume; the dogs hyperventilated at rest and had an increased respiratory response to inhaled CO2. Further cooling of the vagal loops sufficient to abolish the respiratory response to inhaled histamine resulted in the slow, deep breathing pattern and impaired respiratory frequency response to inhaled CO2 typical of the completely vagotomized animal.


Implications of internal loading to breathing in man.


Postural and ventilatory functions of intercostal muscles. During spontaneous breathing, the interchondral muscles present a pattern of activity similar to that of the diaphragm. The external intercostals and most of the internal intercostals generally show electrical discharges not related to ventilatory rhythm. Studies of the electrical responses of these muscles in experimental variations of their length show that the external and internal intercostals are readily activated by this category of reflexes while the diaphragm and the interchondrals are not. Bilateral multisegmental sections of spinal dorsal roots do not affect the respiratory activity of the diaphragm and of the interchondral muscles; on the contrary, all types of activity - spontaneous or reflex - disappear from the intercostals. Electrical stimulation of appropriate points in the bulbar pyramids in decerebrate cats can activate at the same time different intercostals and leg muscles without modifying the rhythmic inspiratory activity of the diaphragm and the interchondrals. In preparations with chronically implanted electrodes, the intercostals muscles are chiefly involved in posture. These results fit very well with our histological findings which disclose a much greater density of muscle spindles in external intercostals than in the diaphragm or in the interchondral muscles.


Studies on the central effects of Hering-Breuer reflexes. In our previous experiments performed with rabbits, it was found out that the strength of both inflation and deflation Hering-Breuer reflexes depends on the level of anaesthesia and ventilation as correlative factors in spontaneously and artificially ventilated animals, though this dependence was quantitatively and qualitatively different in these two groups. On the basis of the recent evidence pointing to the rapidly conducting fibres and thus indirectly the pulmonary stretch receptors as the pathway along which both Hering-Breuer reflexes are transmitted, an attempt has been made to show how both parameters of ventilation are centrally controlled in response to afferent information concerning such mechanical factors as resistance and compliance of the respiratory system. The results presented seem to allow the following conclusions: (i) An important role may be ascribed to the pulmonary stretch receptors in transmission of both Hering-Breuer reflexes. (ii) In quiet breathing the central mechanisms of the Hering-Breuer inflation reflex are set to regulate tidal volume on the basis of analysis of the compliance of the respiratory apparatus at the given moment. Their role to the control of the respiratory frequency is of minor importance. (iii) The contribution of the pulmonary stretch receptors to the control of respiratory frequency is based on information about the resistance of the airways. This parameter influences the ratio of duration of the activity phase to silent phase in discharges of pulmonary stretch receptors.


Studies on central respiratory activity in artificially ventilated rabbits. The level of integrated phrenic nerve activity (C3 root) has been studied under various forms of impairment of respiratory muscle function, such as paralysis (gallamine), pneumothorax and phrenectomy. Experiments were performed in two groups of rabbits artificially ventilated by means of the conventional respirator and the phrenic nerve driven respirator. It was found that both paralysis and bilateral pneumothorax were very strong stimuli exciting central inspiratory activity despite the constancy of ventilation. Under the same conditions phrenectomy caused only slight persistent excitation of the activity studied. It is worth noting that activity in the C3 root contralateral to the cut phrenic nerve trunk was as a rule more strongly stimulated. As artificial ventilation preceded by administration of gallamime is commonly applied in physiological experiments, the possibility of its effect on central respiratory activity will be discussed.


Contribution of various inspiratory muscles to ventilation and the immediate and distant effect of diaphragmatic paralysis. The contribution of the diaphragm and that of the other inspiratory muscles (scaleni and all the other extradiaphragmatic muscles) at different levels of tidal volume (VT) and during static inspiratory efforts of various strengths has been studied in supine anaesthetized rabbits by blocking phrenic conduction with an electrotonic current. Rabbits spinalized at T1 were used to measure the separate contribution of the scaleni. When the vagi are left intact there is an hyperactivity of the extradiaphragmatic muscles during the phrenic block which has been ascribed to Hering-Breuer reflexes. The relative contribution of the diaphragm to tidal volume, during quiet breathing, appears to approach 9O percent and is reduced to 75 percent during the maximum tidal volume attained. The scaleni appear to account for about 1/3 of the tidal volume contributed by all the other inspiratory extradiaphragmatic muscles during quiet breathing and their share goes up to 1/2 at the highest ventilation. The contribution of the scaleni starts at the same level of inspiratory output found for all extradiaphragmatic muscles and therefore these muscles should not be considered "accessory" Within the range of VT considered the sternomastoids did not appear to contribute, as shown by the fact that their disinsertion did not change the results obtained in spinalized rabbits. Immediately after block of the phrenic nerves there is a marked decrease of VT which then increases within 10-15 breaths to a steady value, three to four times that of the first breath after the paralysis, which is maintained thereafter. The respiratory frequency decreases immediately to a slightly lower value after phrenic block In control animals and does not change when the vagi are cut. In any case a fairly steady value is maintained thereafter even when various types of stimulation are applied. Only changes in body temperature could change respiratory frequency. Chronically phrenicectomized rabbits show some compensatory phenomena either functionally or morphologically. They become able to change their ventilation when chemical drive is increased. In the external intercostal muscles the myoglobin concentration increases and ultrastructural modifications become apparent.


Investigation of afferent activity in the intact phrenic nerve with bipolar electrodes. The electrical activity of intact branches of the phrenic nerve was studied during spontaneous respiration in the anaesthetized or decerebrate cat. The action potentials were displayed with opposite polarity according to whether their activity was of afferent or efferent origin. The afferent volleys could be grouped according to three modalities. The first group had a clear silent period during diaphragmatic contraction (72 percent). The second group had volleys during inspiration (25 percent). The third group (3 percent) had rhythmic bursts of fast potentials that were independent of the respiratory cycle.


Afferent vagal impulses in anaphylactic bronchial asthma. The role played by both lung stretch and lung deflation components of the pulmonary vagus has been studied, in order to throw further light on the changes in lung mechanics which underlie the lung deflation receptor activity and hence the activation of respiration during an asthma attack. The discharge pattern of the lung stretch receptors varies from unit to unit, but also in one and the same unit during an asthma attack. The heterogeneous pattern of the stretch receptor units seen during the latter indicates uneven ventilation: the increased stretch receptor activity during both phases of respiration points to overinflation of the lung units concerned during inspiration, and to insufficient relaxation during expiration; the decreased stretch receptor activity in inspiration, combined with deflation receptor discharges in expiration, would indicate that the lung units concerned are poorly inflated during inspiration and subjected to forced deflation during expiration. The reflex mechanisms underlying the activation of respiration during an asthma attack are discussed.


Role of muscle receptors connected to nonmedullated fibres in reflex hyperventilation.


The cyanide gasp and spontaneous deep breaths. Stimulation of the carotid body chemoreceptors with cyanide in anaesthetized rabbits usually causes a deep breath or gasp, but only if the vagus nerves are intact. This gasp has several similarities with spontaneous deep breaths in eupnoea. In paralysed rabbits, artificially ventilated, chemoreceptor stimulation induces an augmented discharge in the phrenic nerve equivalent to a gasp. In spontaneously breathing rabbits spontaneous deep breaths are more frequent with hypoxia than with normoxia. The results are interpreted in relation to (i) positive feedback from the lungs and (ii) summation of chemoreceptor and tonic vagal drive causing augmented deep breaths.


The respiratory action of phenyl diguanide in vagotomized rabbits. In anaesthetized rabbits phenyl diguanide not only stimulates breathing (rapid shallow breathing) by a vagal reflex from lung J-receptors, but also causes a similar response in bilateral vagotomized animals. Injection of the drug into different parts of the circulation indicates that the main non-vagal response of breathing arises from areas supplied by the vertebral arteries, presumably in the brain.


Assessment of differential block of conduction by direct current applied to the cervical vagus nerve. As investigation has been made of the adequacy of direct current to block conduction in the myelinated fibres of the cervical vagus nerve, leaving the nonmyelinated fibres conducting normally. Conduction was assessed from the compound electroneurograms, and from single fibre recording. Conduction of spontaneous activity and the responses to inflation and deflation in single fibres from lung irritant receptors and pulmonary stretch receptors were completely abolished when the A-B wave of the electroneurogram was absent but the C wave was intact. When the direct current was first applied to the nerve, and for periods lasting up to 30 s, there was sometimes a continuous discharge in the single fibres being studied. These results suggest that this method of producing a differential block of conduction in a mixed nerve such as the vagus may be superior to cooling.


The mechanism of tachypnoea in pulmonary microembolism and pulmonary inflammation.


Virus-like structures in muscle in chronic polymyositis.


Dating the development of human cerebellum.


Ultrastructure of a composite glioma-sarcoma of the brain.


Quantitative cytochemical studies of RNA in experimental mercury poisoning. II. Changes in the base composition and ratios.


The earliest alterations in rat neurones and astrocytes after anoxia-ischaemia.


Considerations in the technic of arterial reconstruction following carotid sinus endarterectomy.


Association of soft tissue sarcoma, leukemia, and brain tumors in families affected with breast cancer.


"Chow mein" phytobezoar: the "surgical" Chinese restaurant syndrome.


A method of quick removal of saphenous vein for vascular bypass.


Liver injury in cholelithiasis.

Liver injury in cholelithiasis.


Problems of diagnosing and treating infiltrating lipomas.


Surgical management of thoracic outlet syndrome by first rib resection.


Gunshot wounds of the abdomen.

Gunshot wounds of the abdomen.


Focal nodular hyperplasia of the liver.

Focal nodular hyperplasia of the liver.


Sequential hemodynamic changes in patients with head injury: evidence for an early hemodynamic defect.


Femoropopliteal bypass with reversed autogenous vein.


Chylothorax: indications for surgery.

Chylothorax: indications for surgery.


Experiences with the use of intracholedochal heparinized saline for the treatment of retained common duct stones.


Source of lysosomal enzyme acid phosphatase, in hemorrhagic shock.


Source of a lysosomal enzyme acid phosphatase, in hemorrhagic shock.


Effects of orally administered delta-9-tetrahydrocannabinol in man.


Excretion and metabolism of reserpine in renal failure.


Hemispheric mean transit time of a non-diffusible radioactive tracer in acute stroke.


Familial capillaro-venous leptomeningeal angiomatosis.


Data on the oculopharyngeal syndrome. A clinicopathological study.


Changes in the light-evoked discharges from lateral geniculate nucleus neurones in the cat, induced by caloric labyrinthine stimulation.


Delta-8- and delta-9-tetrahydrocannabinol comparison in man by oral and intravenous administration.


New ideas about drug labels.

New ideas about drug labels.


Effects of caloric labyrinthine stimulation on the spontaneous activity of lateral geniculate nucleus neurons in the cat.


Theophylline compounds and myasthenia gravis. I. In vitro studies.


Parkinsonism treated with 3-O-methyldopa.


Effect of halofenate on exercise performance in coronary heart disease.


The effect of pentothal on the activity evoked in the cerebellar cortex.


Influence of spino-reticulo-cerebellar pathway on Purkynĕ cells of paramedian lobule.


Inhibition of the gastrointestinal absorption of p-aminosalicylate (PAS) in rats and humans by diphenhydramine.


Potentiation of levodopa stimulation of human growth hormone by systemic decarboxylase inhibition.


Cortico-tectal and intertectal modulation of visual responses in the rat's superior colliculus.


Differential synaptic reactivity of simple and complex pyramidal tract neurons at various levels of vigilance.


Photically evoked potentials from cat neocortex before and after recovery from visual deprivation.


Comparative pharmacokinetics of tobramycin and gentamicin.


Integrative functions in the midbrain commissures in fish.


Drug metabolism and androgen control therapy in prostatic cancer.


Elimination kinetics of amobarbital in mothers and their newborn infants.


Cardiovascular responses to electrical stimulation of the amygdala in the rat.


Opposite medial thalamic unit responses to rewarding and aversive brain stimulation.


Inhibition of neurotrophic activity in salamanders treated with opioids.


Effects of denervation on glycoproteins of rabbit gastrocnemius and soleus muscles.


Deafferentation effects in lateral cuneate nucleus of the cat: correlation of structural alterations with firing pattern changes.


Positive inotropic effect of oral esproquin in normal subjects.


Contraceptive use--efficacy study utilizing medroxyprogesterone acetate administered as an intramuscular injection once every 90 days.


Effect of copper intrauterine devices (IUD'S) on estrogen and progesterone uptake by the rat uterus.


Abnormal spermatogenesis in XYY Males: a report on 4 cases ascertained through a population study.


Rabbit sperm capacitation under conditions inhibiting the leukocytic response to the presence of sperm in the female genital tract.


Plasma catecholamine response to exercise and cold adaptation.


Blood gas tensions and pH of pulmonary "wedge" samples in patients with heart disease.


Human hematologic responses to 4 hr of isobaric hyperoxic exposure (100 per cent oxygen at 760 mm Hg).


Posthyperventilation breathing: different effects of active and passive hyperventilation.


Location of airway constriction following acute experimental pulmonary thromboembolism.


Endurance capacity for prolonged exercise on the bicycle ergometer.


Effects of acute alterations of Vo2 max  on endurance capacity of men.


Rapid oscillations in blood glucose and plasma free fatty acid concentrations in man.


Effect of the Valsalva maneuver on tolerance to +G z  acceleration.


Oscillations in oxygen consumption of man at rest.


Basal metabolic and cardiovascular function of women during altitude acclimatization.


Brain organic buffers in respiratory acidosis and alkalosis.


Transvenous phrenic nerve stimulation in anesthetized dogs.


Estimation of tracheal mucous velocity by bronchofiberscopy.


Adrenergic receptors in pulmonary vasoconstrictor responses to gaseous and humoral agents.


Precision gas mixing technique for medical applications.


Monoradicular electrophorenic respiration.


Measurement of ascending aortic flow patterns in man.


Phasic tricuspid flow in chronic unanesthetized dogs.


Micropipette sharpener with audio and hydraulic readouts.


Estimation of maximum oxygen uptake with a brief progressive stress test.


A new method for producing short cardiac Purkinje fibers suitable for voltage clamp.


"Shunt" fractions using O 2  versus N 2 .


A guide for the isolation of the canine brain.


Exposure of the canine proximal AV conducting system for electrophysiologic studies.


Measurement of regional pulmonary parenchymal movement in dogs.


Glossary on respiration and gas exchange.


Resident evaluation--is your method effective?


An epidemiologic approach to cholecystography. A pilot study in Ontario.


Arthrography of rheumatoid synovial cysts of the knee and wrist.


Progress in mammography.

Progress in mammography.


Widening of the median atlanto-axial joint in acromegaly.


Late sequelae of renal trauma in the pediatric age group.


Transfemoral rescue of lost intravascular catheters and guide wires.


Renal milk-of-calcium associated with hydronephrosis.


The surviving lymphocyte "in vitro" after radiation stress: a biologic dosimeter.


Regional migratory osteoporosis.

Regional migratory osteoporosis.


The small orbit sign in supraorbital fibrous dysplasia.


A roentgenographic sign in the diagnosis of postoperative pneumothorax.


Angiographic demonstration of a ruptured spleen causing hemothrax. Case report.


A quantitative evaluation of 70 mm photofluography in the examination of moving vessels.


Conronary arteriography with 70 mm film. Advantages for rapid and reliable demonstration of lesions in the preinfarction syndrome.


A new method for shaping arterial catheters.


Mycoplasma infections in patients with chronic obstructive pulmonary disease.


Humoral and cellular immune responses to an inactivated Mycoplasma pneumoniae vaccine in children.


Mechanism of recovery from systemic infection with vaccinia virus. II. Effects of x-irradiation and neonatal thymectomy.


Mechanism of recovery from systemic infection with vaccinia virus. 3. Effects of antithymocyte serum.


Experimental osteomyelitis. 3. Treatment with cephaloridine.


Multiple attacks of hepatitis in drug addicts: biochemical, immunochemical, and morphologic characteristics.


Concentration of serum immunoglobulins in St. Lucians with schistosomiasis mansoni compared with matched uninfected St. Vincentians.


Seroimmunity to rubella among an Egyptian population.


Effectiveness of current killed influenza vaccines against influenza A-England-42-72.


Chick-embryo deaths traced to tincture of iodine.


Significance of in vitro testing of amphotericin.


Listeriosis in the United States--1971.

Listeriosis in the United States--1971.


Geriatric rehabilitation.

Geriatric rehabilitation.


An intensive care unit in a County Hospital.


The haematological response to a gluten free diet in adult coeliac disease with triple deficiency anaemia.


The fetus: medicine's newest patient.

The fetus: medicine's newest patient.


Beta-blockers in the treatment of hypertension.


Irish delegates' views on specialists training.


Threefold increase in demand for blood concentrates.


Acute glucose loads in insulinized pancreatectomized dogs.


Inhibition of the platelet-dependent fibrin retraction by the fibrin stabilizing factor (FSF, factor 13).


Hepatic bilirubin UDP-glucuronyl transferase activity and cytochrome P450 content in a surgical population, and the effects of preoperative drug therapy.


Comparative effect of chloramphenicol and thiamphenicol on DNA and mitochondrial protein synthesis in mammalian cells.


Iron-binding by macromolecular components of human gastric juice.


Complement as a mediator of inflammation in acute gouty arthritis. II. Biological activities generated from complement by the interaction of serum complement and sodium urate crystals.


The contribution of the colon to electrolyte and water conservation in man.


Detection of type-specific pneumococcal antigens by counterimmunoelectrophoresis. II. Etiologic diagnosis of pneumococcal pneumonia.


Clinical response to amitriptyline among depressed women.


Self-report and clinical interview ratings in depression.


School phobia: diagnostic considerations in the light of imipramine effects.


Heterochromatic additivity, foveal spectral sensitivity, and a new color model.


Carcinoma of the head of the pancreas and periampullary region.


Oral fluid therapy of cholera among Bangladesh refugees.


Radiotherapy in carcinoma of the bladder.


Myocardial contractility of right and left ventricles of variously weighted mammals.


Accessory left atrioventricular connection in type A Wolff-Parkinson-White syndrome.


Insecticide resistance.

Insecticide resistance.


Clinical applications of His bundle electrography.


Pheniramine as an hallucinogen.

Pheniramine as an hallucinogen.


Chloroquine suicide.

Chloroquine suicide.


Pseudomycete mycetoma.

Pseudomycete mycetoma.


Hospital care from general practitioners.


Social medicine in Central Australia.

Social medicine in Central Australia.


Treatment of accidental hypothermia.

Treatment of accidental hypothermia.


Neonatal plasma lipids.

Neonatal plasma lipids.


Properties and mechanism of synthesis of ribosomal RNA in evolution.


Seventeenth annual James B. Herrick Memorial lecture.


Ultrastructural changes in acute myocardial ischemia.


In vitro tests for diagnosis of allergic disease and measurement of allergens.


Asthma and infection.

Asthma and infection.


Stabell U, Stabell B:Chromatic rod vision. 8. Simultaneous contrast.


Chromatic rod vision. VII. Intensity of pre-stimulation varied.


Acute renal ischemic injury.

Acute renal ischemic injury.


Preliminary evaluation of polyethylene graphite as a material for use in total hip replacement.


Individual functions of subjective time distance and emotional reaction.


Catecholamine output in school children as related to performance and adjustment.


Autopsies in hospitals of the Chicago area.


Effects of extraneous stimulation on visual afterimage serials produced by young schizophrenics.


An aggression machine. I. The intensity of aggressive defence aroused by aggressive offence.


Epilepsy: some aspects of aggression, violence, rage, and criminality.


The tuberculin test: present status.

The tuberculin test: present status.


Present-day management of acute myocardial infarction: an outline of policy and practice in the Myocardial Infarction Research Unit at the University of Alabama in Birmingham.


The surgical treatment of vertigo.

The surgical treatment of vertigo.


Septicemia and gastroenteritis due to Vibrio fetus.


Gastritis as a complication of varicella.


Dermatrophy from long-term occulsive topical corticosteroid therapy.


Home dialysis training in a private hospital.


Apnea and atypical pseudocholinesterase.


Removal of cholangiogram catheter from the vena cava and right heart using endoscopic forceps.


Hypertonic saline-induced abortion complicated by consumptive coagulopathy: a case report.


Ichthyosis vulgaris associated with Gilbert's syndrome.


Isolated sublaxation of the carpal scaphoid associated with secondary displacement of the capitate.


The use of minor tranquilizers in a teaching hospital.


Brain abscesses: a ten-year review.

Brain abscesses: a ten-year review.


A rationale for surgery of peptic ulcer.


Current concepts in therapy: vernal conjunctivitis--a simple treatment.


Lymphocutaneous Nocardia brasiliensis infection mimicking sporotrichosis.


Mechanics of isotonic left ventricular contractions.


Hepatic regulation of plasma L-asparagine.


Intrarenal distribution of blood flow during ureteral and venous pressure elevation.


Mechanism of renal clearance of isoproterenol.


Blood flow-limited oxygen consumption in resting cat skeletal muscle.


Evidence for complexing of transcobalamin-2 in canine and human plasma and serum.


Urea metabolism in an estivating terrestrial snail Bulimulus dealbatus.


Components of the action potential of human embryonic auricle.


Influence of chronic acidosis on plasma glutamine and urea production in the nephrectomized rat.


Electrolyte transport in human ileum: effect of purified cholera exotoxin.


Proteolysis in formation of a myocardial depressant factor during shock.


Effect of 2,3-diphosphoglycerate and H+ on the raction of O 2  and hemoglobin.


Temperature regulation and heat balance in running cheetahs: a strategy for sprinters?


Actions and interactions of gut hormones and histamine on gastric secretion of acid in the rat.


Myocardial myoglobin oxygen tension.

Myocardial myoglobin oxygen tension.


Pleural fluid-plasma bicarbonate gradients in oxygen-toxic and normal rats.


Glutamate and glutamine distribution in the rat nephron in acidosis and alkalosis.


Thermosensitivity of medulla oblongata in control of body temperature.


Control of rat adipose tissue metabolism by cortisone in relation to epinephrine.


Mathematical simulation of pulmonary O 2  and CO 2  exchange.


Influence of coronary flow and pressure on cardiac function and coronary vascular volume.


Effect of external calcium and magnesium on thrombin-induced changes in calcium and magnesium of pig platelets.


RNA and DNA of gastric and duodenal mucosa in antrectomized and gastrin-treated rats.


Lack of acute effects of thyroid hormones on myocardial contractility.


Self-stimulation and body weight in rats with lateral hypothalamic lesions.


Stereospecificity of blood-brain barrier permeability to amino acids.


Effects of throxine on calorigenic response of the newborn rat to norepinephrine.


The lessons of radiobiology for diagnostic radiology. Caldwell Lecture, 1972.


Decision processes and observer error in the diagnosis of pneumoconiosis by chest roentgenography.


Solitary mass in the lungs of coal miners.


A phantom for the evaluation of techniques and equipment used for roentgenography of the chest.


Roentgenologic appearance of the chest following radical neck dissection.


Bronchiolitis obliterans. Roentgenologic-pathologic correlation.


How was this chest roentgenogram taken, AP or PA?


Cervico-mediastinal thymic cysts.

Cervico-mediastinal thymic cysts.


Roentgenographic features of thymolipoma.


The retrosternal line. A new sign of an anterior mediastinal mass.


Thermography and venography in tumors of the mediastinum and chest.


Metallic mercury emboli.

Metallic mercury emboli.


Accidental intraarterial injection in drug abuse.


A percutaneous method of introducing the caval umbrella.


Adjustable- versus fixed-fulcrum tomographic systems. A microdensitometric examination of two tomographic systems.


SI units in radiology and radiation measurement.


A simple and cheap remotely operated system for the iodination of proteins.


A simple assay for the study of solubilized acetylcholine receptors.


A simple method for quantitating ligands covalently bound to agarose beads.


A microdetermination of ( 14 C)lactate in biological fluids.


Rapid fluorometric detection for completeness in solid phase coupling reactions.


A simplified high-resolution gradient analysis system.


An automated method for ATP analysis utilizing the luciferin-luciferase reaction.


An automated colorimetric method for the measurement of 3-hydroxybutyrate concentration.


Evaporative thin layer chromatographic separation of hemin dicarboxylic acids.


Estimation of DNA, RNA and  125 I- and  3 H-labelled DNA in the same sample.


Separation of diacetyl, acetoin, and 2,3-butylene glycol by ion-exchange chromatography.


A rapid procedure for the isolation, identification and estimation of citrinin.


A simple, rapid, and sensitive procedure for the estimation of RNA in erythroid cells on fritted glass filters.


Spectrophotometric determination of hydroxyproline in connective tissue on the nanogram level.


Interference by detergents, chelating agents, and buffers with the Lowry protein determination.


Rapid procedure for the isolation of polyfunctional amino acids in elastin.


Monoamine oxidase activity measurements using radioactive substrates.


A direct radioassay of methylmalonyl-coenzyme A mutase using enzymatically synthesized DL-(3- 14 C)methylmalonyl-CoA.


A fluorophotometric method for the determination of amino acids by using pyridoxal and zinc(II) ion.


An automated assay for brain serotonin.

An automated assay for brain serotonin.


Purification of secretory granules on a urografin gradient.


Identification of peptides with 5-dimethylaminonaphthalenesulfonyl chloride.


A simple and sensitive procedure for the detection of sucrose on paper chromatograms.


Rapid nonisotopic assay of tryptophan-5-hydroxylase activity in tissues.


Removal of  -glucosidase impurity from crystalline sweet-potato  -amylase.


Some simple thin-layer chromatographic systems for the separation of purines and purine nucleosides.


Purification of hematohemin IX by column chromatography.


The determination of submicrogram quantities of DNA by phosphorescence analysis.


Production and heat stability of staphylococcal nuclease. No correlation existed between numbers of organisms and nuclease activity in laboratory-grown cultures of Staphylococcus aureus. Nuclease production was inhibited by anaerobic incubation and stimulated by aeration. Strains of S. aureus varied in the production of nuclease. The optimum pH for enzyme production was 8.3 and employment of a tris(hydroxymethyl)aminomethane buffer system resulted in increased production of the enzyme as compared with a phosphate buffer. The nuclease was extremely heat-stable and had a D value of 16.6 min at 130 C.