Role of glucagon, catecholamines, and growth hormone in human glucose counterregulation. Effects of somatostatin and combined alpha- and beta-adrenergic blockade on plasma glucose recovery and glucose flux rates after insulin-induced hypoglycemia. To further characterize mechanisms of glucose counterregulation in man, the effects of pharmacologically inducd deficiencies of glucagon, growth hormone, and catecholamines (alone and in combination) on recovery of plasma glucose from insulin-induced hypoglycemia and attendant changes in isotopically ([3-(3)H]glucose) determined glucose fluxes were studied in 13 normal subjects. In control studies, recovery of plasma glucose from hypoglycemia was primarily due to a compensatory increase in glucose production; the temporal relationship of glucagon, epinephrine, cortisol, and growth hormone responses with the compensatory increase in glucose appearance was compatible with potential participation of all these hormones in acute glucose counterregulation. Infusion of somatostatin (combined deficiency of glucagon and growth hormone) accentuated insulin-induced hypoglycemia (plasma glucose nadir: 36+/-2 ng/dl during infusion of somatostatin vs. 47+/-2 mg/dl in control studies, P < 0.01) and impaired restoration of normoglycemia (plasma glucose at min 90: 73+/-3 mg/dl at end of somatostatin infusion vs. 92+/-3 mg/dl in control studies, P<0.01). This impaired recovery of plasma glucose was due to blunting of the compensatory increase in glucose appearance since glucose disappearance was not augmented, and was attributable to suppression of glucagon secretion rather than growth hormone secretion since these effects of somatostatin were not observed during simultaneous infusion of somatostatin and glucagon whereas infusion of growth hormone along with somatostatin did not prevent the effect of somatostatin. The attenuated recovery of plasma glucose from hypoglycemia observed during somatostatin-induced glucagon deficiency was associated with plasma epinephrine levels twice those observed in control studies. Infusion of phentolamine plus propranolol (combined alpha-and beta-adrenergic blockade) had no effect on plasma glucose or glucose fluxes after insulin administration. However, infusion of somatostatin along with both phentolamine and propranolol further impaired recovery of plasma glucose from hypoglycemia compared to that observed with somatostatin alone (plasma glucose at end of infusions: 52+/-6 mg/dl for somatostatin-phentolamine-propranolol vs. 72+/-5 mg/dl for somatostatin alone, P < 0.01); this was due to further suppression of the compensatory increase in glucose appearance (maximal values: 1.93+/-0.41 mg/kg per min for somatostatin-phentolamine-propranolol vs. 2.86+/-0.32 mg/kg per min for somatostatin alone, P < 0.05). These results indicate that in man (a) restoration of normoglycemia after insulin-induced hypoglycemia is primarily due to a compensatory increase in glucose production; (b) intact glucagon secretion, but not growth hormone secretion, is necessary for normal glucose counterregulation, and (c) adrenergic mechanisms do not normally play an essential role in this process but become critical to recovery from hypoglycemia when glucagon secretion is impaired.


Effects of ascorbic acid and sodium ascorbate on cyclic nucleotide metabolism in human lymphocytes. L-ascorbic acid (LAA) augmented cGMP many-fold in highly purified human peripheral blood lymphocytes. The cGMP response occurred within 10 sec and persisted for at least 60 min. D-ascorbic acid (DAA) and dehydroascorbic acid (DHAA) were also equally active in enhancing cGMP concentrations but metabolic precursors of ascorbic acid and other inorganic acids did not increase cGMP levels. Determination of the amount of DHAA contaminating the LAA precluded the possibility that it was solely responsible for the enhanced cGMP levels. The sodium or calcium salts of ascorbic acid did not increase cGMP concentrations. If these neutralized preparations were acidified, increased cGMP concentrations were then noted. In broken cell preparations, LAA, DAA, and DHAA and to a lesser extent sodium ascorbate (NaA) enhanced guanylate cyclase activity while neither inhibited cAMP or cGMP phosphodiesterase (PDE) activity. The possible role of H2O2, fatty acid liberation, prostaglandin production, oxidizing-reducing agents, and free radical formation in mediating the effects of ascorbic acid on cGMP levels were evaluated, but none of these potential mechanisms were definitively proven to be a required intermediary for the cGMP enhancing activity of ascorbic acid. LAA, DHAA or NaA did not induce lymphocyte transformation or modulate lectin-induced mitogenesis.


Guanylate cyclase in neuroblastoma N1E 115 cells: presence of endogenous activator. Guanylate cyclase in cultured neuroblastoma N1E 115 cells was readily solubilized. MgCl2 as well as MnCl2 served as a metal cofactor of the guanylate cyclase. The maximal guanylate cyclase activity obtained with MgC12 was 80% of that with MnCl2. When the supernatant of cell homogenate was adjusted to pH 5.2, all of enzyme activity was precipitated. The guanylate cyclase activity recovered in the pH 5.2 precipitate was reduced to about 10% of the original supernatant. Combination of the pH 5.2 supernatant and precipitate fractions, however, restored guanylate cyclase activity, indicating that the pH 5.2 supernatant contains an endogenous activator for guanylate cyclase. The activating factor in the pH 5.2 supernatant remained in the aqueous phase after proteins were removed by perchloric acid. The factor was filterable through Diaflo ultrafilter membranes UM 2 and UM 10 indicating that the factor is a small molecule. The activation by the endogenous activator was prevented by N-methylhydroxylamine and lysolecithin.


The effects of H1 and H2 receptor antagonism on the response of monkey skin to intradermal histamine, reverse-type anaphylaxis, and passive cutaneous anaphylaxis. The effects of H1 and H2 receptor anatagonists on models of allergic reactions in monkey skin have been studied. Intradermal histamine is markedly inhibited by H1 receptor antagonists but not by H2 receptor antagonists in the doses used. However, the combination of both receptor antagonists gives greater inhibition than that seen with H1 receptor blockade alone. Reverse-type anaphylaxis is also markedly inhibited by H1 but not H2 receptor antagonists. Passive cutaneous anaphylaxis (PCA) is likewise inhibited by H1 receptor antagonism, but not by H2 receptor antagonism. The combination of the two inhibitors leads to a complete inhibition of this PCA response. The data suggest that the addition of an H2 receptor antagonist may potentiate the effect of H1 blockade alone.


P pulmonale in status asthmaticus.

P pulmonale in status asthmaticus. We studied 129 patients during acute, severe asthmatic attacks. Electrocardiograms showed P pulmonale in 49% of patients who had an arterial carbon dioxide tension (PaCo2) greater than or equal to 45 mm Hg and an arterial pH less than or equal to 7.37, whereas P pulmonale was present in only 2.5% of asthmatics who had a PaCO2 less than or equal to 44 mm Hg and a pH greater than or equal to 7.38 (p less than 0.001). P wave and QRS axes were 79 +/- 8 degrees and 80 +/- 20 degrees, respectively, in the presence of P pulmonale. When P pulmonale disappeared, the P wave and QRS axes shifted significantly to the left (p less than 0.001). Electrocardiographic P pulmonale persisted 12 to 60 hr after correction of hypoxemia, hypercapnia, and acidosis. In 7 patients with P pulmonale and respiratory acidosis, cardiac catheterization demonstrated normal artery pressures (PAPs) measured relative to atmospheric pressure. In 12 of these peak inspiratory pulmonary artery transmural pressures (PATPs) were increased. Since increased right heart transumural pressures could result in chamber distention, these data are consistent with the hypothesis that reversible P pulmonale in status asthmaticus is explainable on the basis of markedly negative tidal pleural pressures and increased right heart transmural pressures.


Effect of a selective beta 2 adrenergic agonist and theophylline on skin test reactivity and cardiovascular parameters. Fenoterol, a selective beta 2-adrenergic agent, and aminophylline in the "therapeutic range" were compared with placebo for their inhibitory effect on skin test reactivity to allergens and histamine. Cardiovascular parameters were also assessed. A new, inexpensive micrometer adaptor to a tuberculin syringe was used to deliver allergens and histamine more accurately. No inhibition of skin test reactivity to antigens or histamine was found after a loading dose or after 1 wk of round-the-clock therapy with these bronchodilators. Although there was increased heart rate after 1 and 2 hr with fenoterol, there was no patient preference for one bronchodilator over the other. The results of this study point out some of the difficulties in trying to extrapolate in vitro findings to in vivo correlates since neither fenoterol nor therapeutic doses of theophylline interfere with immediate skin test reactivity.


Four stimulants of the central nervous system: effects on short-term memory in young versus aged monkeys. Aged Rhesus monkeys and young control monkeys were tested in a delayed-response procedure to assess the effects of central-nervous-system (CNS) stimulants on short-term memory (STM). Previous research had established that the aged monkeys showed specific impairments of STM in this procedure. Four different CNS stimulants (methylphenidate, magnesium pemoline, a pentylenetetrazole/niacin mixture, and caffeine) were chosen for evaluation on the basis of their relevancy to current geriatric-psychopharmacologic research. Four different doses of each of the four CNS stimulants were given to each monkey, counter-balanced for possible order effects. Methylphenidate and caffeine impaired the performance of both age groups in this non-human primate cognitive task, even at relatively low dose levels. Magnesium pemoline produced fewer adverse effects and some evidence of improving STM in the aged monkeys, although not within the levels of statistical significance. The pentylenetetrazole/niacin mixture produced a three-way interaction involving age, dose and retention interval. This reflected the fact that although no definite effects were noted under the zero-sec control condition, statistically significant age-related deficits did occur in the STM-dependent retention interval as the dose varied. The data demonstrate that, of these four CNS stimulants, none radily improves (and often may impair) performance of tasks requiring STM. Thus the results of this study offer little support for the hypothesis that general CNS stimulation may constitute significant therapy for cognitive impairments associated with advanced age.


Fatigue effects on intelligence test performance in the elderly. The purpose of the study was to investigate effects of fatigue on intelligence test performance in the elderly. Dependent variables were Verbal Comprehension, Numerical Facility, Perceptual Speed, and Word Fluency tests. Fatigue effects were investigated by varying the number of previous tests administered, by introducing breaks between tests in some conditions, and by using a pre-test fatigue-producing condition, a modified form of the Finding A's test. Subjects' ages were between 57 to 91-years. It was hypothesized that the Finding A's test would be more fatiguing than a long battery of tests and that introducing a break condition between the Finding A's test and the main battery would alleviate fatigue effects. Analyses of Variance resulted in a main effect due to a pre-test condition for the Perceptual Speed test only, and only when the main battery was preceded by the Finding A's task (p less than .001). It appears that the elderly are not as susceptible to test fatigue as previous results seemed to suggest.


Defensibility of new health professionals at law: a speculative paper. The future of physician's assistants and nurse practitioners will be shaped at least in part by whether, and on what terms, they are defensible at law. This paper explores the way in which the principles of tort law might define primary and secondary liability for these new health professionals. Among the issues discussed in substantial detail are whether a separate standard of care is appropriate, whether the new professionals might function as independent contractors, and the importance of striking an adequate social balance between improved access to health care or cost containment on the one hand and malpractice deterrence or redressment on the other.


Nuclear labeling in immunoperoxidase studies of mouse tissue as detected by staining at acid pH. Several peroxidase-Ig conjugates were applied to sections of fixed mouse tissue. When the peroxidase staining reaction was done at pH 4.5 instead of pH 7.4, a striking reaction on nuclear membrane, chromatin, or chromosomes was observed. This staining was prevented by pretreatment of sections with DNase but not with RNase or after acid elution of histones. It is suggested that at acid pH a redistribution and binding DNA of oxidized chromogen or of a chromogen-conjugate complex to DNA may account for the results observed.


A bacteriological investigation of two leisure centre swimming pools disinfected with ozone. A bacteriological study was carried out on the first Leisure Centre swimming pools in the United Kingdom to be disinfected with ozone/chlorine. Results suggested that a free chlorine concentration of approximately 0.8 mg/l was necessary to maintain the pools in a bacteriologically satisfactory condition. This amount of free chlorine was similar to that required when the pool was disinfected with chlorine alone. However, the associated amount of combined chlorine was much lower when disinfection was by ozone/chlorine and this gave more acceptable bathing conditions. Implications for the manamgement of pools disinfected by this method are discussed.


Human leukocyte inhibitory factor (LIF): two distinct molecular species. Human leukocyte inhibitory factor or LIF was generated in vitro by stimulating blood lymphocytes with concanavalin A (Con A). The control and Con A active supernatants were partially purified by gel filtration on Sephadex G-100. The fraction containing LIF (68,000 daltons) activity was then subjected to isoelectric focusing (pH 3 to 10 ampholines) in a sucrose gradient. Two LIF activities were reproducibly recovered by this procedure. One molecular form was found to have an isoelectric point of approximately pH 5.0 and the other approximately pH 8.5. Both molecular species were rechromatographed on Sephadex G-75 and found to have the same apparent m.w. (68 to 75,000). Furthermore, the biologic activity of both factors was destroyed after treatment with diisopropylphosphofluoridate, suggesting that they may be esterases.


The fate of IgE bound to rat basophilic leukemia cells. The present study investigates the fate of the cell-bound IgE by using a well-characterized rat basophilic leukemia cell line and a purifed IgE myeloma protein. Both histamine-releasing and nonreleasing cell lines were examined. In both cases, no evidence for cell-mediated IgE catabolism could be elicited. Both the dissociated IgE and the receptors remained intact for prolonged periods of time, as demonstrated by binding assays. Internalization and/or recycling of membrane-bound IgE could not be demonstrated by E. M. autoradiography. We found only limited time-dependent changes in accessibility to anti-IgE antibody, trypsin, or elution at low pH (2.9 to 3.1). A biphasic dissociation of cell-bound 125I-IgE during incubation in the presence of excess unlabeled IgE was reproducibly observed; the more slowly dissociated IgE was also less readily dissociated at pH 3.4. These studies lead us to conclude that, in vitro, IgE resides in a functional orientation on the surface of RBL-1 cells, for prolonged periods of time.


Polymorphonuclear leukocyte-mediated, antibody-dependent, cellular cytotoxicity against tumor cells: dependence on oxygen and the respiratory burst. Experiments were done to determine 1) whether the respiratory burst of superoxide anion (O2-) production in polymorphonuclear leukocytes (PMN) is triggered during antibody-dependent killing of tumor cells and 2) whether O2- production is essential for cytotoxicity. Three parameters of the respiratory burst (1-14C-glucose oxidation, oxygen consumption, and O2- release) were increased 2.5- to 7.3-fold during killing of antibody-primed tumor cells by human PMN. Added catalase and superoxide dismutase did not inhibit lysis, possibly because these enzymes were unable to diffuse into the inter-plasma-membrane space between killer and target cells. Evidence for an O2- requirement for cytotoxicity was the fact that concentrations of amobarbital or phenylbutazone sufficient to inhibit the cyanide-insensitive respiration of PMN also inhibited cytotoxicity. Also, hypoxic conditions inhibited cytotoxicity from 29 to 73%. The requirement for oxygen was most likely related to O2- generation and not mitochondrial respiration since cyanide and azide, which inhibit mitochondrial respiration, increased cytotoxicity.


Age-related mitochondrial lipoperoxidation in human skin. Mitochondria were isolated from the epidermis of human subjects of different ages by a procedure that included pretreatment of the tissue with bacterial protease before homogenization. That epidermal mitochondria catalyze enzymatic lipid peroxidation in the presence of NADPH and chelated iron (ADP-Fe3+) is indicated by the production of malonaldehyde. The process does not appear to be influenced by age, and it is strongly enhanced in preparations containing a small amount of melanin.


Effect of reducing agents, catalase, and reuse of medium on toxicity of media for growth of Ureaplasma urealyticum. The effects of catalase and reducing agents on the growth of Ureaplasma urealyticum type VIII in broth cultures were studied, and used medium was examined for the presence of toxic factors. Growth of U. urealyticum was slower in aged or pre-aerated medium than in fresh medium, although equivalent final yields were achieved. Generation times were 2.9 hr in pre-aerated broth and were 1.34 hr in pre-aerated broth supplemented with either 2mM dithioerythritol or catalase (300 units/ml). Growth and death of U. urealyticum in cultures rendered the broth medium deficient for growth when reinoculated. Filtration of spent medium, adjustment of pH, addition of urea, and reinoculation permitted growth at the same rate and to the same titer as that observed in unused medium. Omission of filtration allowed growth but the final yield was less than that in filtered medium. Addition of sonicated dead cells to filtered, supplemented, spent medium also resulted in only poor growth. Therefore, spent medium appears toxic because it contains organisms (either while or disrupted) that hydrolyze the urea added and again render the medium deficient for growth by depleting an essential growth factor.


7alpha-Dehydroxylation of cholic acid and chenodeoxycholic acid by Clostridium leptum. The rate of 7alpha-dehydroxylation of primary bile acids was quantitatively measured radiochromatographically in anaerobically washed whole cell suspensions of Clostridium leptum. The pH optimum for the 7alpha-dehydroxylation of both cholic and chenodeoxycholic acid was 6.5-7.0. Substrate saturation curves were observed for the 7alpha-dehydroxylation of cholic and chenodeoxycholic acid. However, cholic acid whole cell K0.5 (0.37 micron) and V (0.20 mumol hr-1mg protein-1) values differed significantly from chenodeoxycholic acid whole cell K0.5 (0.18 micron) and V (0.50 mumol-1 hr-1 mg protein-1). 7alpha-Dehydroxylation activity was not detected using glycine and taurine-conjugated primary bile acids, ursodeoxycholic acid, cholic acid methyl ester, or hyocholic acid as substrates. Substrate competition experiments showed that cholic acid 7 alpha-dehydroxylation was reduced by increasing concentrations of chendeoxycholic acid; however, chenodeoxycholic acid 7alpha-dehydroxylation activity was unaffected by increasing concentrations of cholic acid. A 10-fold increase in cholic and 7alpha-dehydroxylation activity occurred during the transition from logarithmic to stationary phase growth whether cells were cultured in the presence or absence of sodium cholate. In the same culture, a similar increase in chenodeoxycholic acid 7alpha-dehydroxylation was detected only in cells cultured in the presence of sodium cholate. These results indicate the possible existence of two independent systems for 7alpha-dehydroxylation in C. Leptum.


A dual, concentration-dependent absorption mechanism of linoleic acid by rat jejunum in vitro. Linoleic acid absorption was studied using everted rat jejunal sacs. At low concentrations (42-1260 microM), the relationship between linoleic acid concentration and its absorption rate fitted best to a rectangular hyperbola. At high concentrations (2.5-4.2 mM) the relationship between the two parameters was linear. The separate additions of 2,4-dinitrophenol, cyanide, or azide, or decrease in the incubation temperature from 37 to 20 degrees C did not change the absorption rate of linoleic acid. Absorption rate of linoleic acid at low concentrations increased as the hydrogen ion and taurocholate concentrations were increased or as the unstirred water layer thickness was decreased. Linoleic acid absorption rate was decreased after the additions of lecithin, oleic, linolenic, and arachidonic acids or the substitution of taurocholate with the nonionic surfactant Pluronic F 68. These observations indicate that a concentration-dependent, dual mechanism of transport is operative in linoleic acid absorption. Facilitated diffusion is the predominant mechanism of absorption at low concentrations, while at high concentrations, simple diffusion is predominant. At low concentrations, the absorption rate of linoleic acid is influenced by the pH, surfactant type and concentration, the simultaneous presence of other polyunsaturated fatty acids, and the thickness of the unstirred water layer.


Phosphorus NMR analysis of phospholipids in detergents. Various detergents can be used to dissolve phospholipids, resulting in very narrow 31PNMR resonances. The resonances are well resolved, allowing identification and quantitative analysis of phospholipids in a mixture. The chemical shift depends strongly on pH, reflecting changes in the state of ionization of the phospholipid headgroup moieties. Samples of phospholipids dissolved in aqueous detergents are conveniently prepared and give narrower 31P resonances than do phospholipids dissolved in organic solvents.


Synthesis of two classes of antibody, gammaM and gammaG or gammaM and gammaA, by identical cells. Amplification of the antibody response to pneumococcal polysaccharide type III. Class-specific plaque-forming cell (PFC) (gammaM, gamma1, gamma2, and gammaA) responses to type III pneumococcal polysaccharide (SSS-III) were studied in BALB/c x C57BL/6F1 (CBF1) mice with and without induction of an allogeneic effect. Gamma1, gamma2, and gammaA PFC were detected in two ways: (a) With the sequential development of the assay slides, first for direct (gammaM)PFC followed by incubation with class-specific antiimmunoglobulin and complement for the development of additional gamma1, gamma2, and gammaA PFC (gammaM-independent gamma1, gamma2, and gammaA PFC); and (b) by blocking gammaM PFC with goat anti-gammaM and simultaneously developing gamma1, gamma2, and gammaA PFC (total gamma1-, gamma2-, and gammaA-secreting PFC). The results showed that whereas gammaM PFC arose on the 3rd d after immunization, gamma1-, gamma2-, and gammaA-secreting PFC arose on the 4th to 5th d after immunization. They appeared in association with gammaM-secreting PFC because they were detected with the gammaM blocking method but not with the sequential method. By the 7th d most gamma1, gamma2, and gammaA PFC were detected by the sequential method as well, indicating that those antibodies were secreted independently of cells secreting gammaM. When the numbers of double-class-secreting PFC were evaluated on the 5th d, the following results were obtained: 83% of gammaM PFC were secreting either gamma1 (25%), gamma2 (55%), or gammaA (2%). We interpret these data as evidence for an antigen-driven class differentiation from gammaM to gammaA and from gammaM to gammaG in the majority of anti-SSS-III-secreting clones without T-cell help. When an allogeneic effect was provided by inoculation of parental BALB/c spleen cells together with antigen, the numbers of all classes of PFC were increased. Furthermore, the frequency of gammaM-gammaG (108%) or gammaM-gammaA (9%) double-class secretors was increased, and gammaM-independent gammaG and gammaA secretors were detected earlier, indicating an overall maturation-promoting effect. In addition, prolonged appearance of gammaA PFC was dependent on the allogeneic effect.


Natural, genetically determined resistance toward influenza virus in hemopoietic mouse chimeras. Role of mononuclear phagocytes. Radiation chimeras produced by crosswise transfers of bone-marrow cell among histocompatible mice susceptible, or genetically resistant, to lethal challenge by a number of myxoviruses were used to test whether macrophage resistance (as assessed in vitro) and resistance of the animal (as measured in vivo), both previously shown to be brought about by the gene Mx, were causally related. 49 chimeras were tested individually, both of resistance of their macrophages to in vitro challenge with M-TUR (a strain of avian influenza virus A/Turkey/England/63 adapted to grow in cultured mouse peritoneal macrophages), and for resistance of the animal in vivo upon challenge with pneumotropic, neurotropic, or hepatotropic influenza viruses. Cultivated Kupffer cells and peritoneal macrophages harvested from chimeric mice expressed the resistance phenotype of the bone-marrow donor irrespective of the host environment in which they had differentiated. However, susceptibility or resistance in vivo was according to the genotype of the host. Thus, inborn resistance of radiation chimeras was found to be independent of Mx-gene expression in cells of the hemopoietic system.


Microbial nitrosamine formation in palm wine: in vitro N-nitrosation by cell suspensions. The ability of certain species of bacteria and yeasts that usually contaminate fresh palm sap to induce the formation of the carcinogen dimethylnitrosamine from suitable precursors (trimethylamine, dimethylamine, nitrate, and nitrite) was investigated in vitro under neutral and acid pH conditions. In the incubation media containing cell suspensions of each species of test organism, namely, Aerobacter, Micrococcus, Serratia, Saccharomyces, and two unidentified yeasts and the precursors, added in varying concentrations, the presence of dimethylnitrosamine was indicated. The possible role of indwelling microorganisms in the elaboration of the hazardous compound in fermenting palm wine is discussed.


Some observations of mental illness and its treatment in the People's Republic of China. A visit to the People's Republic of China provided impressions of the use of psychiatric concepts and the organization of mental health services. The Chinese report of low rates of mental illness appears to reflect narrow definitions of disorder and somatic expressions of personal and social distress which are viewed by health personnel as physical conditions. Acute mental health services are provided at commune and county hospitals, and special psychiatric hospitals are maintained for more intractable patients. Chronically disturbed patients may receive long term care in sanatoriums associated with large industries or may be maintained in home beds in their production brigades assisted by family and barefoot doctors. Psychiatric practice in teaching hospitals is similar to psychiatric practice in the West, although little attention is devoted in general medical care to psychosocial problems. Question for future visits and possible collaborative research are suggested.


A comparative study of Zn(II) and Co(II) binding to glycyl-L-tyrosine, a pseudosubstrate for carboxypeptidase A. A comprehensive investigation of the interaction of Zn(II) and Co(II) with the dipeptide glycyl-L-tyrosine has been carried out. The carboxyl, amino, and tyrosyl pKa values, as well as the distribution of solution complexes, have been determined by analytical potentiometry. The amide pKa value was determined by relating the proton magnetic resonance (PMR) titration behavior of the tyrosyl alpha-hydrogen resonance to an H2-acidity function for concentrated solutions of aqueous base. Both metals behave in a qualitatively similar manner, yielding equivalent species as a function of pH. Both metals formed bis-peptide complexes, involving amino and peptide carbonyl coordination near pH = 8, with Zn(II) demonstrating a substantially higher affinity for the ligand. No evidence could be found for direct, metal-promoted phenolic dissociation, although the tyrosyl pKa value was sensitive to metal binding at other loci on the dipeptide molecule. At high pH, both systems ionized two additional protons. In the Co(II) system, these correspond to amide protons. However, it is not entirely clear whether the protons in the Zn(II) system originate from the peptide linkage or metal-bound water molecules.


Persistent changes in central catecholaminergic system after recovery of perinatally undernourished rats. Pregnant rats from day 14 of pregnancy or pups were fed a control diet (24% casein) or a deprived diet (8% casein) in order to obtain the following groups: 1) Control (C-C group); 2) Prenatal deprived (D-C group); 3) Postnatal deprived (C-D group); 4) Pre and postnatal deprived (D-D group). From 50 days of age on, all groups were fed a balanced commercial stock diet until 140 days of age. A significant reduction in corporal and brain weights was observed in C-D and D-D groups during deprivation and after nutritional recovery. Twenty-four day old deprived rats showed a decrease in brain noradrenaline (NA) content but no significant change in NA concentration. By the end of the deprivation period (50 days), brain NA levels tended to be reduced or increased in postnatal deprived rats, depending upon the method of expressing the results (microgram NA/whole brain or microgram NA/g fresh tissue, respectively). At 140 days of age, i.e., after 90 days of nutritional recovery, no differences were detected between deprived and control rats. However, conversion rate of [14C]tyrosine to brain catecholamines and tyrosine-hydoxylase activity were higher in D-D rats as compared with controls at this age. These results suggest that perinatal undernutrition produces, even after a prolonged period of nutritional recovery, a permanent activation of the central catecholaminergic system in adulthood. This fact may explain the different behavioral alterations described as a consequence of protein deprivation in early life.


Improved oxygenation and lung compliance with prone positioning of neonates. Fourteen intubated infants recovering from neonatal respiratory disease had arterial blood gases and lung mechanics measured in the supine position and in two variants of the prone position. Prone positioning resulted in significant increases in mean (+/- SEM) arterial oxygen tension (Pa(o2 70.4 +/- 2.5 to 81.1 +/- 4.4mm Hg), dynamic lung compliance (1.7 +/- 0.24 to 2.55 +/- 0.37 ml/cm H2O),and tidal volume (8.6 +/- 1.0 to 10.5 +/- 1.2 ml) when all prone values were compared to supine values. Prone positioning with the abdomen protruding freely, when compared to all supine values, was associated with significantly increased dynamic lung compliance and tidal volume. Values for prone-abdomen free were not significantly different from values for prone-abdomen restricted. This suggests that there are clinical benefits from prone positioning in neonates recovering from respiratory disease.


The response to an oral glucose load during convalescence from hypoxia in newborn infants. The ability to tolerate an oral glucose load during convalescence from hypoxia was studied in four term and 11 premature appropriate-for-gestational-age infants by sequential measurements of the changes occurring in blood pH, bicarbonate, plasma lactic acid, and plasma glucose following an oral glucose load. All infants developed metabolic acidosis and lactic acidemia after the oral glucose load. The maximum fall in blood bicarbonate occurred at 30 minutes, and the maximum rise in plasma lactic acid concentration was attained at 60 minutes. The metabolic changes were found to be more severe in infants given the oral glucose load early in their convalescence and in those infants less than 10 days of age. The absorption of glucose was also decreased in these infants, as shown by a reduced rise in blood sugar. These observations indicate that newborn infants, term or premature, tolerate glucose loads poorly during convalescence from hypoxia.


Acetoacetyl CoA thiolase deficiency: a cause of severe ketoacidosis in infancy simulating salicylism. A female child presented at one year of age with a febrile illness and loose stools, then developed severe ketoacidosis with vomiting; an apparent salicylate level of 11 mg/dl was measured. A sibling had died in similar circumstances nine years earlier. Investigation revealed that the child did not have salicylate intoxication, and that high levels of acetoacetate in blood and urine were giving readings indicative of the presence of salicylate on routine testing. Gas-liquid chromatographic analysis combined with mass spectrometry on urine samples revealed the presence of 2-methyl-acetoacetate, 2-methyl-3-hydroxybutyrate, and tiglyl glycine in appreciable amounts, indicating a defect in isoleucine catabolism located at the beta-ketothiolase step. The oxidation of 14C-isoleucine to CO2 in cultured fibroblasts confirmed that this pathway was defective. We present evidence that beta-ketothiolase deficiency is not simply a defect of isoleucine degradation; the deficient enzyme is the K+ dependent short-chain mitochondrial thiolase, which also plays a major catalytic role in ketone body and fatty acid oxidation.


Diurnal variation in the quality and outcome of newborn intensive care. Variables related to both the process and the outcome of neonatal intensive care were studied to compare care given during the day (0901-2100 hours) with that at night (2101-0900 hours). At night, intravenous infiltrations occurred more often, and the tidal volume of respirator-treated infants was verified less often. Blood pH values less than 7.20, excluding values within 12 hours of admission, were recorded more often and in more patients at night. During a 12-month period, there were significantly more deaths among infants less than 1,500 gm during the night than during the day. The deterioration of infants at night may result in part from current nursery staffing practices.


The granulation of ternary mixtures containing lactose and boric acid with different starches. Ternary mixtures of lactose, boric acid and starch have been granulated by massing and screening. The properties of the granules have been compared with those resulting from granulation of blends of lactose and boric acid without starch. Potato, maize and rice starches have been studied as the third component at concentrations similar to those employed in tablet formulations. The starches caused a reduction in both mean granule size and granule strength. The effect is dependent on the proportions of the excipients. Increasing the amount of binder solution used gave bigger, stronger granules but did not compensate for the effects produced by the starches.


The effect of simultaneous administration of 3,4-dihydroxyphenylpyruvic acid and L-dopa on the bioavailability of L-dopa in rat and mouse. In the rat, administration of 3-(3,4-dihydroxy)-L-phenylalanine (L-dopa) simultaneously with the corresponding alpha-keto acid, 3,4-dihydroxyphenylpyruvic acid (DHPPA), gives significantly higher concentrations of L-dopa in the serum and of dopamine and homovanillic acid in the brain than the same dose of L-dopa alone. Correspondingly, DHPPA potentiates the effect of L-dopa on the locomotor activity in reserpine-treated mice. DHPPA is postulated to increase the absorption of intact L-dopa from the gut by preventing the transamination reaction between L-dopa and the physiological alpha-keto acids.


Depletion of brain noradrenaline, but not dopamine, by intracerebral 6-hydroxydopamine potentiates convulsions induced by electroshock. Intracerebral injection in rats of 4 microgram of the catecholamine neurotoxin 6-hydroxydopamine was used to deplete forebrain noradrenaline to less than 10% of control values and separately to deplete brain dopamine to less than 15% of control. The susceptibility of these animals to electroconvulsive shock-induced convulsions was examined, and a significant potentiation of the response was seen in the rats depleted of noradrenaline but not in those depleted of dopamine. The duration of the convulsion was significantly increased as a result of loss of forebrain noradrenaline.


The effects of treatment and of withdrawal of treatment with guanfacine and clonidine on blood pressure and heart rate in normotensive and renal hypertensive rats. Disagreement in the literature about the occurrence of rebound hypertension (hypertensive overshoot) in animal models initiated this investigation. Oral doses of clonidine (0.03 mg kg-1) or guanfacine (0.3 mg kg-1) were administered twice daily during three weeks to groups of normotensive and renal hypertensive rats. Blood pressure and heart rate were measured immediately before and 3 h after the first daily dose, and compared with values obtained from placebo-treated control rats. Treatment with either drug induced large daily fluctuations rather than sustained falls in blood pressure. In the normotensive, but not in the hypertensive groups, the morning blood pressures measured before the first daily dose were significantly elevated over those of the control groups after 9 and 5 days of treatment with clonidine or guanfacine. This elevation persisted for 3 days after drug withdrawal. It is concluded that in the rat the duration of action of both drugs was short, so that twice daily administration of both drugs similarly produced large daily fluctuations rather than sustained falls in blood pressure. Blood pressure rises developed during treatment rather than after withdrawal in normotensive rats only. Therefore, this type of study does not relate well to the human situation and different experimental approaches to this problem are needed.


Characterization of receptors on postganglionic cholinergic neurons in the guinea-pig isolated ileum. Dopamine, apomorphine, noradrenaline and isoprenaline reduced the response of the isolated guinea-pig ileum to exogenous acetylcholine by a maximum of 40%. Propranolol reversed this inhibition whilst phentolamine and pimozide were ineffective, suggesting that the drugs were acting on a post-synaptic beta-adrenoceptor. The same agonists were more effective as inhibitors of the response to transmural electrical stimulation of the ileum, lower doses producing almost complete inhibition. This inhibition was partially antagonized by phentolamine, pimozide and propranolol. Clonidine proved to be the most potent inhibitor of the response to transmural electrical stimulation, whilst phenylephrine was ineffective. pA2 determinations showed that phentolamine was a potent antagonist of clonidine but a weak antagonist of apomorphine whilst for pimozide the opposite was true. The results suggest that there are two populations of prejunctional receptors on the cholinergic nerves innervating the smooth muscle of the guinea-pig ileum. One receptor is similar to a classical prejunctional alpha-adrenoceptor and the other resembles a central dopamine receptor.


Effect of naloxone on the sensitivity of the vas deferens to various agonists. The effect of naloxone in vitro, on noradrenaline (NA)-induced responses in guinea-pig isolated vas deferens was studied. The responses of NA were potentiated by naloxone (3 microM). It potentiated the responses to methoxamine which has least affinity for uptake sites. Responses induced by acetylcholine and potassium chloride were also potentiated by naloxone. Low calcium (0.8 mM) in the medium antagonized the potentiating action of naloxone. It is suggested that naloxone produces non-specific potentiation, by promoting calcium influx at the post-synaptic site.


The non-specific membrane binding properties of delta9-tetrahydrocannabinol and the effects of various solubilizers. The binding of [3H]delta9-tetrahydrocannabinol to crude and purified synaptosomal membrane suspended in either Krebs solution or 10 mM sodium phosphate buffer was examined. The membrane/buffer partition coefficient was found to be 12,500, and was constant over a free concentration range of 10(-8) to 10(-6)M. Binding was similar in both suspending media, and to both crude and purified synaptosomal membrane. The solubilizing agent Cremophor E.L. (8 microgram ml-1) decreased the partition coefficient by one-half, and by greater than 99% at 0.4 mg ml-1. Similar effects were observed with Tween 80, while ethanol caused a maximum decrease of 60%. Membrane concentrations of THC were calculated at various effective concentrations reported in the literature, and were within the range predicted by the Meyer-Overton rule of anaesthesia. An apparent non-specific interaction with neuronal membranes and effective membrane concentrations of the order 2 x 10(-4) to 1 x 10(-2) mol kg-1 suggests THC may exert some of its effects by a mechanism analogous to the general anaesthetics, and thus may be classified as a partial anaesthetic.


Acidic metabolites of delta1-tetrahydrocannabinol isolated from rabbit urine. The in vivo metabolism of delta1-tetrahydrocannabinol (delta1-THC) was investigated in the rabbit after i.v. administration. Thirteen acidic metabolites were isolated from rabbit urine and identified by gas chromatography-mass spectrometry and by proton magnetic resonance spectroscopy. One additional metabolite was tentatively identified. All but three were new metabolites and all but one were oxidized in the pentyl side chain. The metabolites included dicarboxylic acids, monocarboxylic acids and mono- or dihydroxylated derivatives thereof. However, the dicarboxylic acid metabolites were the most prominent.


More acidic metabolites of delta1-tetrahydrocannabinol isolated from rabbit urine. The in vivo metabolism of delta1-tetrahydrocannabinol (delta1-THC) was further investigated in the rabbit after i.v. administration. Nine acidic metabolites were isolated from a previously not investigated fraction of the urine and identified by gas chromatography-mass spectrometry and by proton magnetic resonance spectroscopy. The major metabolites were side-chain hydroxylated monocarboxylic acids. Three side-chains monocarboxylic acids hydroxylated in allylic positions in the isoprene moiety were also characterized. The metabolites 4''-hydroxy-delta1-THC-7-oic acid and 7-hydroxy-4'',5''-bisnor-delta1-THC-3''-oic acid were hitherto not identified. An earlier described dicarboxylic metabolite was present in high concentration. Further, the identity of an O-glucuronide as an in vivo urinary metabolite of delta1-THC was here for the first time unambiguously established by m.s. and p.m.r.


A laboratory animal model for malignant hyperpyrexia. Strandard laboratory rabbits which are not genetically susceptible to malignant hyperpyrexia were anesthetized with either halothane or pentobarbital. Administration of caffeine in 125 mg increments produced a syndrome strongly resembling malignant hyperpyrexia in rabbits anesthetized with halothane. All these animals became rigid, hyperpyrexic, acidotic and hyperkalemic, whereas caffeine-treated, pentobarbital-anesthetized animals developed only mild acidosis. Pentobarbital alone and halothane alone caused no changes in measured variables. This model for malignant hyperpyrexia resembles the naturally occurring disease more closely than several preceding pharmacologic models.


Ca2+ control of electrolyte permeability in plasma membrane vesicles from cat pancreas. The influence of Ca2+ and other cations on electrolyte permeability has been studied in isolated membrane vesicles from cat pancreas. Ca2+ in the micromolar to millimolar concentration range, as well as Mg2+, Sr2+, Mn2+ and La3+ at a tested concentration 10(-4) M, increased Na+ permeability when applied at the vesicle inside. When added to the vesicle outside, however, they decreased Na+ permeability. Ba2+ was effective from the outside but not from the vesicle inside. When Ca2+ was present at both sides of the membrane, Na+ efflux was not affected as compared to that in the absence of Ca2+. Monovalent cations such as Rb+, Cs+, K+, Tris+ and choline+ decreased Na+ permeability when present at the vesicle outside at a concentration range of 10 to 100 mM. Increasing Na+ concentrations from 10 to 100 mM at the vesicle inside increased Na+ permeability. The temperature dependence of Na+ efflux revealed that the activation energy increased in the lower temperature range (0 to 10 degrees C) when Ca2+ was present at the outside or at both sides, but not when present at the vesicle inside only or in the absence of Ca2+. The results suggest that the Ca2+ outside effect is due to binding of calcium to negatively charged phospholipids with a consequent reduction of both fluidity and Na+ permeability of the membrane. The Ca2+-inside effect most likely involves interaction with proteins with consequent increase in Na+ permeability. The data are consistent with current hypotheses on secretagogue-induced fluid secretion in acinar cells of the pancreas according to which secretagogues elicit NaCl and fluid secretion by liberating Ca2+ from cellular membranes and by stimulating Ca2+ influx into the cell. The increased intracellular Ca2+ concentration in turn increases the contraluminal Na+ permeability which leads to NaCl influx. The luminal sodium pump finally transports Na+ ions into the lumen.


Delayed-onset pulmonary insufficiency in primates resuscitated from hemorrhagic shock. Forty-one unanesthetized cynomolgus monkeys were subjected to 2 hours of hemorrhagic hypotension at various mean arterial pressures (MAP) between 40 and 60 mm Hg. Resuscitation and maintenance of MAP were provided by lactated Ringer's solution and homologous blood. Thirty-eight per cent (57% of those surviving greater than 24 hours) developed a delayed-onset (18 to 24 hours) pulmonary insufficiency in spite of good urinary output, and which did not respond to furosemide. The group in which this caused death (24%) showed significantly decreased PaO2, PaCO2, dynamic compliance, and FECO2, and increased minute volume, Qs/Qt, pulmonary artery pressure, and VD/VT before death. Their lungs were heavier, with abnormal pressure/volume curves and increased minimum surface tension. During the entire post-resuscitation phase, this group remained in a high-output, low-resistance hemodynamic state in contract to survivors and those dying of shock. The implications regarding current practices of monitoring and resuscitating patients with traumatic shock are discussed.


Chronic hepatic encephalopathy. Long-term therapy with a branched-chain amino-acid-enriched elemental diet. Therapy of chronic hepatic encephalopathy is often frustrating, limited as it is by the ability to adequately nourish such patients. Protein is needed for repair, but such patients are intolerant of protein. Previous work from this and other laboratories has suggested that the distorted plasma amino acid pattern may be causally related to hepatic encephalopathy. A single, well-studied, long-term patient received therapy with a branched-chain amino-acid-enriched elemental diet that not only enabled adequate nutrition with protein but resulted in improvement in hepatic function as well as reversal of some aspects of hepatic encephalopathy that heretofore have been deemed irreversible. The results confirm that branched-chain-enriched amino acid diets previously successful in the intravenous mode may be successfully used in chronic long-term support of patients with protein intolerance, with improvement in hepatic function secondary to improvement in nutrition.


Experimental central hypertension produced by chemical degeneration of the locus coeruleus in the rat. The role of noradrenergic neurons originating from the locus coeruleus (LC) in blood pressure regulation was studied by stereotaxic administration of 6-hydroxydopamine (6-OHDA) into the LC in Wistar-Kyoto rats. The administration of 6-OHDA (12 micrograms/6 microliters) into the bilateral LC resulted in hypertension and tachycardia, which lasted for 12 days and gradually returned to the levels observed before administration. The systolic blood pressure and heart rate were 172 mmHg and 460 beats/min on the mean respectively, one day after administration. The induced hypertension and tachycardia were closely correlated with the depletion of norepinephrine (NE) content in the cortex and the medulla-pons in rats in a hypertensive state. The correlation between the NE content of the cortex and blood pressure was particularly marked (r = -0.793, p less than 0.02). Furthermore, destructive change of the LC was observed histologically in the hypertensive rats. They hypertension was completely prevented by pretreatment with desipramine before 6-OHDA administration. These findings suggest that 6-OHDA induced degeneration, probably mainly in the dorsal bundle originating from the LC and in the LC itself. It is suggested, therefore, that localized chemical degeneration of the bilateral LC causes hypertension and tachycardia as a consequence of denervation of the dorsal bundle of noradrenergic neurons originating from the LC.


Intracellular pH and plateau duration of internally perfused squid giant axons. The effects of changing the intracellular pH on the action potential duration and other electrophysiological properties were studied in squid giant axons perfused intracellularly with TEA(tetraethylammonium)-containing solutions and under Ca-Na bi-ionic conditions. The duration of the action potential plateau, produced by TEA, was markedly decreased with acidic intracellular solutions and increased with alkaline intracellular solutions. The normalized duration, d, was calculated by dividing the plateau duration by that of the standard intracellular pH of 7.3, and plotted against the intracellular pH. The curve could be expressed by the formula log [d/(D-d)] = n(pH-pK') where D is the saturated value of d, n a constant and pK' the value of pH at which d becomes D/2. The values selected for D and n were 2.6 and 1.4, respectively. The pK' was found to be 7.5. Lowering of the extracellular pH to 6.2 only slightly changed the plateau duration. Voltage clamp analysis revealed that acidic intracellular solutions decreased the size of the inward current and the slope conductance which were measured at the late period of the depolarizing clamping pulse. Alkaline intracellular solutions increased the size of the inward current and the slope conductance measured at this late period. Intracellular perfusion with a low pH solution also shortened the duration of the Ca-Na bi-ionic action potential. It is argued that the remarkable generality of the pH effect on the plateau duration implies the existence of a common mechanism of formation of the plateau under widely differing experimental conditions.


Effects of procaine on the ventricular muscle of bullfrog. The effects of procaine on the contractility of the bullfrog's ventricular muscle were investigated. The addition of 10(-5) g/ml of procaine potentiated the twitch tension which was accompanied by an elevation as well as a prolongation of the action potential plateau. This positive inotropism of procaine was not induced by endogenous catecholamine because a beta-blocking agent did not influence this twitch potentiation. The twitch potentiation was increased in proportion to the external Ca concentration, suggesting the possibility of augmentation of Ca influx during the action potential. In normal Ringer solution, procaine suppressed potassium contracture which was composed of two components: an initial phasic component and a late tonic one. Potassium contracture after perfusion with Ca-free solution was also suppressed by procaine. However, potassium contracture which had been treated previously with La was composed of only a tonic component and was potentiated by procaine in spite of perfusion with Ca-free solution. The tonic component of potassium contracture may be considered to occur with intracellular Ca. Procaine may increase the Ca inward current, acting on the intracellular Ca storage site and consequently accelerate the excitation-contraction coupling in frog ventricular muscle.


Acid- and cryoactivation of renin in human plasma. Inactive renin in normal human plasma was activated in vitro either by cryoactivation (incubation at 0 degrees C/-5 degrees C up to 3 months) or acid-activation (dialysis to pH 3.0 for 48 h followed by diaylsis to pH 7.5). Plasma-renin-concentration was similar after either activation procedure (96 +/- 50 microU/ml vs 100 +/- 43 microU/ml). There was no further significant acid-activable renin after cryoactivation. These data suggest that conversion of inactive to active renin by optimized procedures is complete. The term "total renin" for activation results under these conditions seems to be valid.


[Catecholamines and their metabolic enzymes in the hypothalamus of rats after a flight on the Kosmos-782 biosatellite]. The concentration of catecholamines, and activity of enzymes involved in their synthesis (tyrosine hydroxylase and dopamine-beta-hydroxylase) and degradation (monoamine oxidase) were measured in the hypothalamus of rats flown for 19.5 days aboard the biosatellite Cosmos-782, synchronous and vivarium controls sacrificed on R+O and R+25 days. No significant changes in the above parameters of the flight rats were found. The findings give evidence that a prolonged space flight induces no changes in the content, synthesis or degradation of catecholamines in the rat hypothalamus. This seems to indicate that weightlessness does not act as an acute stressor.


[Helium-oxygen mixture and the body (the hyperbaric aspect)]. A review of publications discussing the effect of hyperbaric He-O2 atmosphere demonstrates that its effect on the human body depends primarily on its physical parameters, density and heat conductance. Another specific effect of the atmosphere--its narcotic effect at increased pressures used in diving--still remains poorly documented. However, it appears a well recognized fact that the specific effect can be seen only in the transition period, i. e. during compression.


[Probability of altitude decompression sickness during a suited exit from a space ship having a near-Earth atmosphere]. A large number (550) pressure chamber experiments in which 200 suited subjects simulated an egress from the spacecraft (decompression from 760 to 20--10 mm Hg) showed a relationship between decompression sickness frequency and severity, space suit absolute pressure (160--310 mm Hg), time of the exposure (1--10 hours) and desaturation (15--60 min), and exercise load (150--400 Cal/hr). Without desaturation there were no decompression sickness symptoms at a suit pressure of 270--310 mm Hg. An egress into space in a suit at a pressure of 160--230 mm Hg after 15--60 min desaturation induced bends of different severity. Less frequent cases of decompression sickness in our experiments as compared with the literature data (obtained on unsuited subjects) can be attributed to the peculiar kinematics of movements and excessive pressure in the suit.


[Dislocations of the talus (author's transl)]. Authors analysing 31 case histories of talus fractures and following the results in 22 cases over a period of 3--12 years support the general view, that the healing of such injuries is satisfactory but partial or even total necrosis may occur. They emphasize the importance of X-ray investigation and occasional phlebography in order to clear up the state of circulation in the bone. Weight bearing should be decided in accordance with these examinations.


[Angiography for the changes of arterial network in experimental tubular pedicle flaps (author's transl)]. Authors performed on rabbits experimental tubular pedicles and pedicle transfers investigating by means of fill up angiography the changes occuring in the arterial network. They conclude that in the tubular pedicles the adapting of blood supply to the changed circumstances result in transformation of arterial network. There are similar alterations after transposition of the tubular pedicles. Details of changes in vascularisation are given.


[Characteristics of the proteins of unicellular organisms as potential components of ecological life-support systems]. A comparative characterization of the biological value of proteins from green and blue-green algae, bacteria, and microbial coenosis of straw mineralizing active sludge is given with respect to the fractional composition of total protein, its amino acid composition, and affinity for proteolytic enzymes in vitro. The above microorganisms have an adequate amino acid composition, a high content of essential amino acids, and differ in their content of readily soluble proteins. The presence of protein complexes with other cellular components, for instance lipids and carbohydrates, seems to be responsible for a poor digestibility of these proteins.


[Primary spleen ruptures with problematic diagnosis (author's transl)]. The clinical appearance of primary spleen rupture with latent bleeding is dealt with. Diagnostic difficulties, possible methods of examination and their evaluation are demonstrated. Selected characteristic cases from among their material are introduced.


[Muscle hernia causing compression to the superficial peroneal nerve (author's transl)]. Author describe a rare condition of long peroneal muscle hernia, which caused severe nerve compression pain. After nerve decompression and fasciotomy the complains could be eliminated. The condition when discovered, operation should be done in a short time in order to avoid permanent nerve damage.


[Development of bony bridge between lumbar vertebrae (author's transl)]. Authors report on a case observed in a child developing bony bridge between the transverse processes of lumbar vertebrae. They believe this alteration is a developmental anomaly.


[Restriction of extension caused by organized haematoma on hand (author's transl)]. A case of organizing haematoma on hand resulting in restriction of extension is reported on. Operative treatment was followed by complete healing.


[Septic complications following thermic injuries (author's transl)]. The occurrence of septic complications after burns depends first of all from the surface extension of thermic injury and the age of patient. The expansion of the indication for primary excision doesn't change a great deal the frequence of septic occurences. Insufficient excision and skin covering to the other hand can be the source of lethal infection. Secondary skin grafting is an important mean for eradicating obvious sepsis. From among the parenchymal localisations the septic lung complications take the first place, which fact can be in connection with the thermic injury of the respiratory tract.


[The part taken by X-ray investigation for closed soft tissue injuries on the extremities (author's transl)]. Special X-ray pictures taken of soft tissues for the treatment of closed soft tissue injuries on the extremities, give valuable diagnostic advises. Rupture on the surface of muscles, the lesion to the tendon Achilles and the lig. patellae proprium, tumours, muscle waisting following plexus or periferial nerve lesions etc. by X-ray investigation can be exactly delineated and the site, extension and type of damage defined.


[Replacement of skin defects on the foot with dorsal foot artery pedicle island flap (author's transl)]. On the basis of four known cases, authors describe the art. dors. pedis pedicle island flap method (McCraw, Furlow) for replacement of skin defects on the foot. The pedicle of the flap is composed of the art dors. pedis, the vena comitans and the peroneal nerve. The flap is suitable for replacement of skin defects around the external or internal malleolus, on the margin of the sole and heal, over the tendon Achilles as well as on the anterior surface of the lower third leg. Vascular anatomy of the island is described and details of the technics for the formation of island are given. Beside the good vascular supply the importance of innervation is emphasized.


[Conservative treatment of supracondylar humerus fractures in children with Blount's method (author's transl)]. Author treated during the period of 1971--78, 84 patients with supracondylar humerus fractures using the method of Blount for fixation. Based on experiences gained by follow up examination 2--5 years after the first treatment, author states, that this method yielding good functional results, by its simplicity and efficiency is an excellent and feasible procedure for selected supracondylar humeral fracture cases.


[Fractures of the tarsal navicular bone (author's transl)]. Analysing 17 cases of navicular fracture, authors divide the fracture dislocations in two groups. The importance of X-ray pictures in oblique views and the frequent occurence of simultaneous foot injuries is pointed out. On follow up examination of 13 fractures 3--8 years after injury authors observed in general severe arthritis, subjective impressions of the patients and the results of rehabilitation on the other hand were satisfactory. Their result suggest in cases of dorso-medial dislocation, in order to avoid redislocation, a wire pinning or open screw fixation or rather as an exception primary desis. In cases of lateral dislocation the fracture is not prone to redislocation therefor a conservative treatment is sufficient.


Medical treatment of pancreatic insufficiency. Treatment of exocrine pancreatic insufficiency with the use of eight tablets of pancreatin with meals consisting of 25 g of fat per meal will generally abolish azotorrhea. Although steatorrhea is not totally corrected, satisfactory nutritional status and relative relief of symptoms are usually achieved. For the occasional patient who continues to lose weight or remains symptomatic even after reduction of dietary fat, the addition of cimetidine to the standard pancreatin treatment will usually provide relief from the steatorrhea and alleviate troublesome diarrhea. In certain circumstances in which gastric pH is more than 4 for 1 hour after a meal, altering the dosage schedule to two tablets hourly may be effective in alleviating the steatorrhea. Conversely, in patients whose upper gastrointestinal tract is acidic for long periods postprandially (gastric pH less than 5, duodenal pH less than 4), Pancrease, an enteric-coated preparation, may be effective. In difficult cases in which symptoms and steatorrhea continue, special intraluminal studies need to be performed to ensure that intraluminal conditions are, in fact, present for certain dosage schedules to be effective or that intraluminal conditions have been altered by adjunctive therapy.


Protein synthesis in neural cells in culture: role of cell density and neurohumors. Protein sythesis was studied in C-6 glial cells and neuroblastoma (NB) cells as a function  of cell density and after differentiation with dibutyryl cyclic AMP and treatment with either norepinephrine (NE), dopamine or L-dopa. In both C-6 glial cells and NB cells, unincorporated 3H-leucine decreased, whereas incorporation of 3H-leucine into protein increased with increasing cell density, particularly at high cell densities. Exposure of C-6 glial cells of NE at various dose for 60 minutes stimulated the efficiency of 3H-leucine corporation into protein. This effect was not seen with L-dopa or dopamine. In contrast to the glial cells, in neuroblastoma cells, all three neurohumors caused a decrease in the incorporation of 3H-leucine into protein. The increase in protein synthesis by NE was also seen in DBcAMP-differentiated glial cells. These findings suggest that cellular activity as reflected by protein synthesis is cell density dependent. In addition, neurohumor substances may play a regulatory role in the cellular activity of glial cells.


A re-appraisal of the productivity potential and economic benefits of physician's assistants. A combined optimization-simulation model is used to examine the extent of productivity and economic benefits to be gained from adding a physician's assistant to a one-physician ambulatory health care practice. It is shown that previous models (which have predicted productivity gains as large as 90 per cent) have overstated these benefits by ignoring offsetting changes in patients' waiting time, waiting room congestion, practice hours, and supervisory requirements. When all these factors are considered, the productivity gain may be as small as 20 per cent, and the increase in net income may be negligible. The sensitivity of productivity and net income to changes in supervisory requirements is also examined. This paper suggests that a rational explanation exists for the reluctance of physicians to adopt physician's assistants in their practices. The economic benefits derived from adding a physician's assistant may well have been overstated in the existing literature.


Otitis media in children: a prospective study of aerobic and anaerobic bacteriology. Tympanocentesis with aerobic and anaerobic cultivation of middle ear fluid was performed through one or both tympanic membranes of 186 children with acute otitis media. Aerobic bacteria alone, predominantly pneumococcus and Hemophilus influenzae, were isolated from 118 (63.4%) patients: and anaerobic organisms alone, most commonly Peptococcus, from 24 (12.9%). Twenty-six (14%) yielded mixtures of aerobes and anaerobes, and several had multiple aerobic agents. No bacterial growth was noted in 18 (9.7%) patients. The isolation of anaerobic bacteria alone, supported in some patients by Gram-stain observations of middle ear fluid, suggests that these bacteria, especially Peptococcus, may occasionally play a direct role in acute otitis media.


Insulin release: the fuel hypothesis.

Insulin release: the fuel hypothesis. The immediate and direct regulation of insulin release by circulating nutrients, especially glucose, is thought to be mediated in the pancreatic B-cell by a sequence of metabolic, ionic, and motile events. On the basis of previous work, it is assumed that the process by which glucose is recognized as an insulinotropic agent entirely depends on the metabolic changes evoked by the sugar in the islet cells. Several factors are considered as possible candidates for the coupling between these metabolic changes and subsequent ionic events such as altered phosphate, chloride, sodium, potassium, and calcium handling. It is acknowledged that changes in the concentrations of glycolytic intermediates and cyclic nucleotides (adenosine- or guanosine-3', 5'-cyclic monophosphate), or both, could play a modulatory role upon stimulated insulin release. However, the initiation of insulin release seems to depend on the generation of two essential coupling factors: H+ and reduced pyridine nucleotides. The changes in H+ fluxes may account for the glucose-induced decrease in K+ and Ca2+ fractional outflow rate, all three parameters displaying hyperbolic-like dose-response curves with half-maximal values at noninsulinotropic glucose concentrations. The changes in NAD(P)H concentration may account for a glucose-induced Ca2+--Ca2+ exchange process due to a change in affinity of a native ionophoretic system. The dose-response curves for these parameters yield a sigmoidal pattern analogous to that which depicts the rate of insulin release at increasing glucose concentrations. It is proposed that such a coupling between metabolic and cationic events is operative in response to other insulinotropic nutrients and that its time course may be relevant to the phasic aspect of insulin release. Thus, the nutrient-induced release of insulin (and possibly other pancreatic hormones), which is essential for the regulation of fuel homeostasis, would depend on the capacity of circulating nutrients to act as a fuel in the islet cells. This concept raises a question as to the existence and nature of feedback mechanisms regulating the metabolic fluxes in the islet cells as a function of their energy expenditure.


Effect of pH, light intensity and population on the toxicity of the pesticide carbofuran to the blue-green alga Nostoc muscorum. The effect of pH, light intensity and population on the toxicity of the pesticide furadan (containing 3% carbofuran as the active ingredient) was studied on the nitrogen fixing blue-green alga Nostoc muscorum. It was observed that all these factors had effects on the toxicity of the pesticide. The blue-green alga grew better in the pH range of 7.5-10, whereas the acidic pH of 5-6 retarded growth. The pesticide was more toxic to alga in the medium of pH 5-6, whereas reduction in toxicity was noticed in alkaline pH of 7.5-10. The alga grew slowly in a light intensity of 1,500 lux in comparison to a light intensity of 3,000 lux, and no growth occurred in the dark. The toxicity of the pesticide gradually decreased with increasing light intensity. The toxic effect of the pesticide was increased when the initial population level was low, and increasing the initial population reduced the toxicity.


Mechanism of glucan-induced agglutination in Streptococcus mutans. I. Binding of radioactive glucan to whole cells of S. mutans OMZ-176. The binding of radioactive glucan to Streptococcus mutans cells, which are agglutinated by dextrans, was examined. The glucan was synthesized from sucrose by extracellular glucosyltransferases from S. mutans FA-1 and was highly branched at C-3 and C-6 of D-glucose residues, containing 17% of a (1 leads to 3)inter-chain residues. Binding of glucan to whole cells of S. mutans OMZ-176, which were agglutinated by addition of glucan or Dextran T2000, was irreversible and followed saturation type kinetics; saturation was achieved at approximately 110 ng of glucan per ml. About 14 ng of glucan were bound per mg of the cells at the saturated concentration. The heated cells of this organism, however, had a relatively low ability of glucan-binding, compared with the freshly prepared and lyophilized cells. Binding to the heated cells was entirely of a non-saturation type. Binding of Dextran T2000 or T10 was determined by competition between the labeled glucan and unlabeled Dextrans for the binding site(s). Both Dextrans and glucan from S. mutans FA-1 were bound to the same site(s). Other organisms, which did not undergo glucan- and Dextran-induced agglutination, had a relatively lower ability of glucan-binding than S. mutans, which was agglutinated.


[Mechanism of action of D-amino acid oxidase. II. Evidence for the free radical mechanism of the reaction catalysed by the monomer form of the enzyme]. D-Amino acid oxidase was shown to dissociate into subunits in 2 M urea retaining the catalytic activity. This makes possible the direct observation of ESR spectra of the intermediate radical state of the enzyme when interacting with the substrate. We have shown that these radicals are really observable. Using the reversibility of the reaction and an equilibrium shift the amount of radicals can be increased up to 10% of all flavin groups present. The dependence of the radicals concentration on the amount of substrate and product can be predicted. The theory is confirmed by experimental data.


[pH-dependence of fluorescence parameters of chymotrypsin, chymotrypsinogen, trypsin and lysozyme]. The alterations of tryptophan fluorescence parametres with pH may be due to: 1) conformational changes; 2) changes in the ionic state of groups capable of quenching the tryptophan fluorescence. The applications of the model of discrete forms of tryptophan allow one to separate these mechanisms and estimate the middle points of conformational changes and pK's of quenching groups. For chymotrypsin (CT) and chymotrypsinogen (CTG) conformational changes were registrated with middle points: CT pH 4.1 and 8.8; CTG -- pH 3.2 and 9.8, and pK's of histidines: CT -- 5.4 and 6.6; CTG -- 5.6 and 7.0. For trypsin conformational changes were shown with middle points: pH 3.2; 5.8; 8.5 and for lysozyme -- pH 5.9.


[Influence of pH and thermal treatment on the intramolecular mobility of pepsin]. In connection with a hypothesis of segmental flexibility of pepsin and its derivative aminopepsin (containing 3-aminotyrosine residues), a dynamic behaviour of pepsin and dansylated aminopepsin in aqueous solutions at pH 1.0--8.3 in investigated. It is shown that a dynamic structure of pepsin at pH 2.5--6.0 is almost invariant and very close to a structure studied in detail at pH 5.5. The lowering of a solution pH value from 2.5 to 1.0 is accompanied by labilization of pepsin and dansylated aminopepsin structures. Denaturation phenomena after thermal treatment of dansylated aminopepsin are also studied. An incubation of the latter in 0.1 M acetate buffer at pH 5.5 and temperature 50--80 degrees C with a subsequent cooling leads to irreversible conformational changes. The character of these changes is essentially dependent upon the incubation conditions.


[Compact form of DNA in solution. XII. Double-stranded polyribonucleotide compacting in the presence of polyethylene glycol]. Double-stranded polyribonucleotides (a replicative form of phage f2 RNA--dsRNA and poly(A) poly(U), can adopt a compact from in solutions, containing NaCl and poly(ethylene glycol) (PEG). According to electron-microscopic observations dsRNA compact particles have the form of disks or doughnuts 200--400 A in diameter. X-ray diffraction patterns from dense slurries of dsRNA compact particles show a reflection at a spacing of 35 A, which is indicative of the existance of ordered regions in compact particles. The intense positive CD band, which is characteristic of dsRNA and poly(A) poly(U) compact particles, presumably results from the ordered regions in the particles. Heating of the solution leads to the disappearance of the intense positive CD band, probably as a result of the destruction of the ordered structure of compact particles. Heat or acid denatured dsRNA molecules as well as single-stranded molecules of ribosomal RNA also form large particles in PEG-containing solutions. However, X-ray diffraction patterns from these particles do not show the 35 A reflection and the specific positive band is not present in their CD spectra, which indicates that such particles lack ordered internal structure. It is suggested that similar mechanism of compactization of double-stranded polynucleotides (DNA and RNA) exist, and compact particles may be divided into two families (psi+ and psi-), differing by the secondary structure of double-stranded polynucleotides, which form the particles.


[Photooxidation of aspartate transaminase from chicken heart cytosol]. Rose-bengal-sensitized photooxidation of aspartate transaminase from chicken heart cytosol results in a loss of enzymatic activity which follow first order kinetics down to 70--75% inactivation. 0.9 Histidine, 0.9 tryptophane residues and 1.5 SH groups per enzyme subunit were found to be modified in the photooxidized transaminase, which retained 26% residual activity. Photodestruction of the coenzyme was about 16%. The rate of enzyme photoinactivation is constant in the pH range 6--8, and drastically decreases with lowering pH from 6 to 4. alpha-Ketoglutarate partially protects the holoenzyme from inactivation. The apoenzyme undergoes photoinactivation at a rate almost twice as rapid as the holoenzyme. Photooxidized apotransaminase retains affinity to pyridoxal phosphate and binds as much coenzyme as the native apoenzyme. Photooxidation induces no significant alterations in the circular dichroism pattern of the enzyme in the 200 to 240 nm range. However, positive circular dichroism is markedly increased in the absorption bands of aromatic amino acids (260--300 nm). The affinity of photooxidized holoenzyme for glutarate and alpha-methyl aspartate is greatly decreased. On the other hand, photooxidized enzyme retains its ability to bind alpha-alanine and to catalize the transamination half-reaction between alpha-alanine and the bound coenzyme. These findings imply that photooxidation disturbs the binding of the distal carboxyl group of dicarboxylic substrates. This may be due to a localized conformational change induced by destruction of a photoreactive histidine residue at the active site. A role of the histidine residue in transamination reaction is discussed.


[Kinetics of alpha-chymotrypsin catalyzed hydrolysis in equilibrium. III. Rate constants for individual stages and thermodynamic parameters at different pH's]. The rate constants of the individual steps of the reversible chymotryptic hydrolysis of N-acetyl-L-phenylalanylglycinamide and methyl N-acetyl-L-phenylalaninate have been calculated on the basis of data on the velocity of the exchange between these substrates and products of their hydrolysis at equilibrium and also on the basis of steady-state kinetics of their cleavage. This was done for peptide substrate at pH 5.5, 7.3 and 8.2 and for ester substrate at pH 5.5. The free energy of the formation of intermediate complexes and free energy of activation were calculated. Thus a complete kinetic and thermodynamic description of chymotryptic catalysis of various pH is performed.


[Construction of partial denaturation charts for DNA with random base distribution]. By measuring DNA temperature transition profiles the evidence was obtained that DNA of phages Tg9 and OB infecting Bacillus thuringiensis and Brevibacterium flavum respectively have a random base distribution. After alkaline treatment in the presence of 10 per cent formaldehyde at room temperature partially denatured molecules of phage Tg9 and OB DNA's with different degrees of denaturation were obtained. Using electron microscopy the maps of distribution of melted regions along these DNA's were obtained. The location of the main peaks on histograms did not vary with the increase of the degree denaturation and changes of pH values. The map of Tg9 DNA is characterized by four main peaks located at the positions 0.031, 0.075, 0.145 and 0.885 but the map of OB DBA is characterized by seven main peaks located at positions: 0.09, 0.20, 0.34 0.42,0.49, 0.80 and 0.88 from the left end (in relative units). The increase of denaturation up to a certain value did not change the half-width of the main peaks at the maps of these DNA's. It may be due to the presence in the DNA's some "heat stolle" sequences limiting early melting DNA regions.


[Peptidyltransferase center of ribosomes. Structure and relationship to other ribosomal functions]. Structural analysis of the ribosomal peptidyl transferase center using model substrates "minimal" peptide acceptors and donors is reported in the present work. Recent data on the ribosomal proteins and rRNA organizing the peptidyl transferase center and other functional centers of the large ribosomal subunits are given and the know facts about the catalytic mechanism of the peptide bond formation are considered. An analysis of the interaction of the peptidyl transferase center and the centers binding the cytoplasmic translocation factors and stringent-factor (for E. coli ribosome) is presented; a possible contribution of the peptidyl transferase center ot the translocation is discussed.


Cyclophosphamide therapy of severe systemic necrotizing vasculitis. We studied 17 patients with severe systemic necrotizing vasculitis over an 11-year-period. Sixteen patients were treated daily with cyclophosphamide (2 mg per kilogram per day), and one was treated with azathioprine (2 mg per kilogram per day). Before entering the study, all patients had active and progressive disease, even though 16 patients had been receiving corticosteroids that had caused severe and often incapacitating toxic side effects. Three patients died during the study. Complete and often dramatic remissions occurred in the surviving 14 patients, who were then placed on alternate-day corticosteroid treatment with continuation of cyclophosphamide. Corticosteroids were later discontinued in seven patients. The mean duration of remission was 22 months (range, two to 61). No patient showed recurrence of disease during treatment with cytotoxic agents.


[Determination of the antibacterial activity of various mycotoxins using Bacillus thuringiensis (Berliner)]. Antibacterial activity of pure preparations of mycotoxins, was studied against strains of Bacillus thuringiensis (Berliner). Most of fungal metabolites used provokes: 1) Growth bacterial inhibition similar to lethal effect of antibiotics 2) Enlargment of cell volume; this cell abnormality induction resembles those obtained with mitomycin C. The bioassay of fungal toxins with B. thuringiensis can be recommended as a sensitive technique to supplement chemical characterization. By using specific cell lines to such a mycotoxin and specific inactivators as coumarin for aflatoxin, or sulfhydryl compounds for penicillic acid and patulin.


Hypothermic action of lisuride in rats and differences to bromocriptine in the antagonistic effect of neuroleptics. The semisynthetic ergot derivative lisuride induced dose- and time-dependent hypothermia in rats placed in a cold environment (+4 degrees C). As regards dosage, lisuride was more than 100 times more effective in this test model than bromocriptine. The effect of both drugs could be reduced by pretreatment with the dopamine antagonist haloperidol, which indicated a dopaminergic action of both drugs. In contrast, the hypothermic effect of lisuride could not be impaired by pretreatment with sulpiride, whilst the effects of bromocriptine were clearly antagonized by this drug. This results could be explained by a different affinity of these drugs to the same receptors, or, more likely, by a different mechanism of action by which lisuride and bromocriptine activate dopaminergic systems.


Juvenile-onset metachromatic leukodystrophy: biochemical and electrophysiologic studies. A 15-year-old girl with juvenile-onset metachromatic leukodystrophy (MLD) had markedly decreased leukocyte arylsulfatase A activity and low levels of leukocyte beta galactosidase and serum acid phosphatase. There was marked slowing of nerve condition velocity, and metachromasia was seen in biopsied sural nerve. Leukocyte arylsulfatase A activity was decreased in all members of the girl's family, and sural nerve action potentials were abnormal in two asymptomatic siblings. Electrophysiologic studies combined with biochemical studies may aid in the identification of presymptomatic metachromatic leukodystrophy homozygotes or asymptomatic heterozygotes.


Neural mechanisms in acupuncture analgesia. The summary of the nervous levels implicated in analgesia in general helps one to understand that the acupuncture analgesia is not simply a psychological or sociological matter as some said when it first appeared. Its mechanisms are the same as the ones existing in other antalgic therapeutics whether nervous or humoral. Not everything has been explained in the action of acupuncture but acupuncture opens new ways to us in the practical field of controlling pain as well as in the theoretical field of pain, the major problem of all the medicines.


[Experience with detoxification and weaning of heroin addicts by means of acupuncture, gabergic drugs and psychopharmacologic agents in low doses]. Presents extensive reports of detoxification and habit loosing trials in 9 male heroine addicts, 19-26 yr. The therapeutic programs were centered on gabergic drugs, low doses tricyclic antidepressants and benzodiazepines, and acupuncture (main points: 8 GB; nasal GB; 1 GB; 3 L; 4 LI; 36 S; 7 H; auricular Shen men) and were continued weekly at the Mental Health Outpatients Service, after discharge from the hospital. 2 Ss, personally checked, abstinent 6 months after their discharge; 4 Ss heard as abstinent and 3 Ss relapsed. Technique, course and times of the therapeutic program seem to be one of the key factors for success.


The microbiology of serous and mucoid otitis media. One hundred forty-four serous and mucoid effusions were cultured for aerobic bacteria, Mycoplasma pneumoniae, and virus. Thirty percent of all effusions yielded an unequivocally positive culture for aerobic bacteria. Although serous effusions were culture positive as often as mucoid effusions, Haemophilus influenzae was isolated predominantly from serous effusions and Staphylococcus epidermidis predominantly from mucoid samples. Only one of 73 effusions yielded a viral isolate (Herpesvirus hominis). None of 33 effusions yielded M pneumoniae, and only one of 17 effusions yielded an anaerobe (Propionibacterium). These findings suggest that aerobic bacteria may play a role in the pathogensis of serous and mucoid otitis media.


Effect of variations in blood hydrogen ion concentration on pulmonary gas exchange of artificially ventilated dogs. The effect of variation of blood hydrogen ion concentration on arterial and mixed venous PO2, ideal alveolar-arterial O2 pressure difference (PAiO2--PaO2), venous admixture (Qs/Qt), arterio-alveolar CO2 pressure difference (a--A)DCO2, physiological dead space to tidal volume ratio (VD/VT), cardiac output (Qt) and mean pulmonary arterial pressure (PAP) has been studied. Arterial and mixed venous PO2 increased and (PAiO2--PaO2) decreased with increasing blood hydrogen ion concentration. No change in Qs/Qt, (a--A)DCO2, VD/VT, Qt and PAP was observed. The effect of hydrogen ion concentration on arterial and mixed venous PO2 and on (PAiO2--PaO2) is mainly due to a shift of the blood oxyhemoglobin dissociation curve (ODC), i.e. due to the Bohr effect. The upper part of the ODC is more flat in alkalosis (shift to the left) than in acidosis (shift to the right). Therefore the same end-capillary to arterial O2 content difference results in a greater (PAiO2--PaO2) in alkalosis than in acidosis. Any factor influencing the slope of the upper part of the ODC is expected to affect the arterial PO2 and the (PAiO2--PaO2) by this mechanism. Similarly any factor shifting the steep part of the ODC is expected to affect the PO2 of the mixed venous blood.


The effects of pH on Ca2+-activated force in frog skeletal muscle fibers. Ca2+-activated isometric force was recorded is skinned (sarcolemma mechanically removed) segments of frog skeletal muscle fibers immersed in bathing solution of different pH (5.0--10.5) and Ca2+ concentrations. Force in maximally activated fibers was near zero at pH 5.5, increased as pH increased to 7.5, remained relatively constant until pH 9.0 and then rapidly declined to zero by pH 10.5. The Ca2+ concentration at which 50% of maximum force was developed decreased 25-fold as pH increased from 5.5--7.5. The data also indicate that, while the fibers remains viable with acidosis, they deteriorate rapidly with alkalosis. These observations may be relevant clinically, since they parallel known effects of acidosis on cardiac contractility. The possible sites of action of H+ on the Ca2+-activated force generating mechanisms are discussed.


[Clinical trials in psychiatry. Recent evolution of the methodology in France (author's transl)]. The comparison, with the help of a check list of criteria, of psychotropic clinical trials published in France, with an interval of five years, covered 80 trials in 1970 and 75 trials in 1975. The differences found between these two years all indicate a stricter methodological approach in 1975. Certain gaps persist however, such as the extreme rarity of codified pretherapeutic evaluation, preliminary wash out periods, references to an official nosography and a sufficient homogeneity of treatment groups. On the other hand, in the majority of trials, the exclusion criteria are not given and a global clinical assessment is the only criterium of change used. Finally the conclusions proposed coincide with the data in only two thirds of the publications. The comparative revue of 120 controlled psychotropic trials so far published in French show above all the extreme variability of the type of control utilized. Only 58 trials out of 120 have been randomized and a minority of these were carried out according to a strict methodology, with quantitative evaluation of the results and an appropriate statistical analysis. The most frequent methodological insufficiences are the obvious heterogeneity of the treatment groups, the insufficient use of standardized evaluation instruments and the inadapted ness of certain experimental protocols to the goals being pursued. The points most frequently omitted in the presentation of the results are the drop-outs of treatment, information relating to associated and previous treatment, the dates of evaluation of the therapeutic effects as well as the approach used to established side effects. The recent application of the 1975 French Law has deeply changed the habits of French experimentators and it is necessary to correctly interpret the term of "control". The control of non-specific variables intervening in the therapeutical results is the only means of identifying the pharmacological effects of drugs. The best control of these variables is the randomized comparative trial of simultaneous treatment groups using double-blind prescriptions. In order to further comparisons of trials from different sources, it is absolutely necesary that evaluation studies in French be carried out and transmitted according to internationally recognized recommendations based on general rules of protocols and on standardized evaluation instruments.


Effect of 5-bromodeoxyuridine on heterogeneous nuclear RNA in rat hepatoma cells. Heterogeneous nuclear RNA HnRNA) was isolated from untreated and 5-bromodeoxyuridine (BrdUrd) treated hepatoma tissue culture (HTC) cells. analysis of this RNA by either electrophoresis on polyacrylamide-agarose gels or centrifugation in sucrose gradients demonstrated that BrdUrd caused a shift in the labeled HnRNA population toward a smaller size distribution. This effect was produced by concentrations of BrdUrd which specifically lower the level of the differentiated enzyme tyrosine aminotransferase, but do not greatly affect cell growth. Differential binding to oligo(dT) cellulose was used to fractionate HnRNA further into classes containing poly(A) (alpha), oligo(A) (beta) or neither category of A-rich sequences (gamma). BrdUrd did not alter the relative rates of uridine incorporation into the three classes. The shift in the labeled HnRNA population due to BrdUrd was observed in all three subclasses of HnRNA.


Detection and accumulation of tetrahedral intermediates in elastase catalysis. Tetrahedral intermediates in the reaction of elastase with specific di- and tripeptide p-nitroanilide substrates have been detected, accumulated, and stabilized at high pH by using subzero temperatures and fluid aqueous/organic cryosolvents. The tetrahedral adducts are characterized by spectra with lambda max of 359 +/- 2 nm, compared with thata of 380 nm for p-nitroaniline and 315-320 nm for the substrates. The maximal concentration of intermediate that could be accumulated varied with the different substrates from 40 to 100% of the active enzyme present. The pH dependence of the reactions indicated that formation of the tetrahedral intermediates was rate-limiting at low pH (pK* = 7.0 at -39 degrees C) and that collapse to the acylenzymes was rate-determining at high pH. When corrected for the effect of temperature and cosolvent, the rate of intermediate formation was in good agreement with that measured at 25 degrees C in aqueous solution by stopped-flow techniques.


Alteration in structure of multifunctional protein from Chinese hamster ovary cells defective in pyrimidine biosynthesis. A combined genetic, biochemical, and immunological approach has clarified structural relationships involving the first three enzymes of de novo pyrimidine biosynthesis. A procedure involving antibody and protein A-Sepharose was used to isolate the enzymes carbamoyl-phosphate synthase [ATP:carbamate phosphotransferase (dephosphorylating, amido-transferring), EC 2.7.2.9], aspartate transcarbamoyltransferase (carbamoylphosphate:L-aspartate carbamoyltransferase, EC 2.1.3.2), and dihydro-orotase (L-5,6-dihydroorotate amidohydrolase, EC 3.5.2.3) from Chinese hamster ovary cell CHO-K1, the uridine-requiring auxotroph Urd(-)A, and selected Urd(-)A revertants. The enzymes of Urd(-)A and the Urd(-)A revertants were significantly altered in activity, native structure, and molecular weight from those of CHO-K1. The results presented permit the conclusion that (i) these three enzymes reside in a single multifunctional 220,000-dalton polypeptide; (ii) the aspartate transcarbamoyltransferase activity is located on a portion ( approximately 20,000 daltons) at one end of the polypeptide; (iii) this portion may also be required for monomers to aggregate into the multimeric from present in mammalian cells; (iv) the mutations in Urd(-)A and the Urd(-)A revertants lie in the structural gene for this multifunctional protein; and (v) increased sensitivity to proteases could account for the alterations in the structure of these enzymes in the mutants.


Lysosomal arylsulfatase deficiencies in humans: chromosome assignments for arylsulfatase A and B. Genetics of human lysosomal arylsulfatases A and B (aryl-sulfate sulfohydrolase, EC 3.1.6.1), associated with childhood disease, has been studied with human-rodent somatic cell hybrids. Deficiency of arylsulfatase A (ARS(A)) in humans results in a progressive neurodegenerative disease, metachromatic leukodystrophy. Deficiency of arylsulfatase B (ARS(B)) is associated with skeletal and growth malformations, termed the Maroteaux-Lamy syndrome. Simultaneous deficiency of both enzymes is associated with the multiple sulfatase deficiency disease, suggesting a common relationship for ARS(A) and ARS(B). The genetic and structural relationships of human ARS(A) and ARS(B) have been determined by the use of human-Chinese hamster somatic cell hybrids. Independent enzyme segregation in cell hybrids demonstrated different chromosome assignments for the structural genes, ARS(A) and ARS(B), coding for the two lysosomal enzymes. ARS(A) activity showed concordant segregation with mitochondrial aconitase encoded by a gene assigned to chromosome 22. ARS(B) segregated with beta-hexosaminidase B encoded by a gene assigned to chromosome 5. These assignments were confirmed by chromosome analyses. The subunit structures of ARS(A) and ARS(B) were determined by their electrophoretic patterns in cell hybrids; a dimeric structure was demonstrated for ARS(A) and a monomeric structure for ARS(B). Although the multiple sulfatase deficiency disorder suggests a shared relationship between ARS(A) and ARS(B), independent segregation of these enzymes in cell hybrids did not support a common polypeptide subunit or structural gene assignment. The evidence demonstrates the assignment of ARS(A) to chromosome 22 and ARS(B) to chromosome 5. A third gene that affects ARS(A) and ARS(B) activity is suggested by the multiple sulfatase deficiency disorder.


H+/site, charge/site, and ATP/site ratios in mitochondrial electron transport. H(+)/site, charge/site, and ATP/site ratios have been determined at coupling sites I, II, and III. Three e(-) donors have been used for coupling site III: ferrocyanide, ascorbate + tetramethyl-p-phenylenediamine (TMPD), and succinate + TMPD. The H(+)/site ratios are 4.0 with ferrocyanide and 6.0 with succinate + TMPD (at pH <7.0); the charge/site ratios are 6.0 with ferrocyanide and with succinate + TMPD (at pH <7.0) and 4.0 with ascorbate + TMPD; the ATP/site ratio is 1.34 with ascorbate + ferrocyanide. These ratios have been obtained in the presence of amounts of antimycin A that provide full inhibition of site II. For coupling sites I and II, ferricyanide has been used as e(-) acceptor and succinate or NAD-linked substrates as e(-) donors. The H(+)/site ratios are 4.0 at sites I and II; the charge/site ratios are 4.0 at site I and 2.0 at site II; the ATP/site ratios are 1.0 at site I and 0.5 at site II. Two major factors affect the stoichiometries: (i) dimension of [unk](H) and (ii) supply of H(+) from the matrix. There is a correlation between collapse of [unk](H) and increase of H(+)/site and charge/site ratios. This indicates that approximation of the phenomenologic stoichiometry of the H(+) pump is obtained when flow ratios are measured at level flow. That charge/site and ATP/site ratios increase when ferrocyanide is e(-) donor and decrease when ferricyanide is e(-) acceptor is attributed to the localization of the redox couple. This leads to separation of 1 charge/e(-) when ferrocyanide is e(-) donor and to consumption of 1 charge/e(-) when ferricyanide is e(-) acceptor. To account for an extrusion of H(+) in excess of that predicted by the loop model, it is proposed that each coupling site contains a channel acting as a H(+) pump.