[Serum gamma-glutamyl-transpeptidase and alcoholism. Diagnosis and control of withdrawal]. The gammaGT of a generally healthy population is abnormally high due to the presence of ethanol in the diet. We confirm Rosalki's finding that a high proportion of alchoholics show an increased gammaGT activity. After alcohol deprivation, the gammaGT of alcoholics decreases in the first few days according to an exponential law with a half-time of return to normal of 5-17 days. Among past alcoholics, those who stopped drinking for a year have a lower GT activity (mean: 21 mU/ml) than a generally healthy population and in the range of Szasz's reference values. Alcoholics who did not stop drinking have a higher gammaGT activity (mean: 172). Ascitic cirrhotics who drink at least 1 liter of wine per day have also a high activity (mean: 139) while those who stopped drinking for at least 2 months have a much lower activity (mean: 49) and those who stopped for a year a normal activity. In 10 out of 11 alcoholic cirrhotics who stopped drinking, the gammaGT decreased (half-time: 11-54 days). These results show that the determination of gammaGT activity is a good test for the detection of ethanol impregnation.


Protonated polynucleotide structures.  16. Thermodynamics of the melting of the acid form of polycytidylic acid. A phase diagram (pH, ionic strength, temperature) for the double helical form of poly(C) is presented. The thermo-dynamic analysis of these data shows that poly(C) behaves essentially as cytidine, if the electrostatic (ionic strength) contributions and the free energy of double helix formation are considered and taken into account.


Size fractionation of double-stranded DNA by precipitation with polyethylene glycol. We show that DNA molecules of differing molecular mass are separable by selective precipitation with polyethylene glycol (PEG+.. Higher molecular mass DNA precipitates at lower PEG concentrations than lower molecular mass DNA. Double-stranded DNA can be fractionated at least in the range of 3 times 10-7 to 1 times 10-5 daltons. The effects on PEG concentration, sodium chloride concentration, DNA concentration, pH, divalent ions, precipitation time, and centrifugal force have been determined. These studies show PEG precipitation offers a size fractionation method for DNA which is convenient, of high capacity, and applicable over a wide range of conditions. However, resolution is not high and separation of two species approaches 100% only if they differ in molecular mass by at least a factor of two.


Transfer RNA methyltransferases from yellow lupin seeds: purification and properties. tRNA methyltransferases from extract of yellow lupin seeds were purified over 300-fold by the methods based on hydrophobic and affinity chromatography. However, in the most active fractions the methylating enzymes were over 2000 purified. The purified enzyme fractions catalysed the formation of 1-methyladenine and 5-methylcytosine using E. coli B and B. subtilis tRNAs as substrates and S-adenosylmethionine as the methyl donor. They were unable to methylate their own endogenous tRNA but they were capable of methylating tRNA of some other lupinus species. Whereas the patterns of methylated constituents of tRNA of some other lupinus and B. subtilis were quite similar, they differed considerably from those obtained with lupin species tRNAs. Some properties of purified methyltransferases from yellow lupin seeds have been described.


The interaction of ribonuclease T 1 with DNA. The interaction of RNase T1 with calf thymus DNA was studied using uv difference spectroscopy and the effect of the enzyme on DNA melting. There was no indication of RNase T1 binding with native DNA. A prominent difference spectrum for RNase T1 binding with denatured DNA (d-DNA) was observed at pH 5, 25 degrees and low ionic strength (mu = .01 M) which was depressed at higher ionic strength and pH. The normalized difference spectrum at mu = .01 M, pH 5 and 25 degrees can be interpreted as indicating an interaction of an exposed guanine residue directly with the enzyme and a coupling of this process with the "melting" of short folded segments of d-DNA. The apparent association constant calculated per M guanine residues was 2.4 X 10-4 M-1 under these conditions. The results are discussed in reference to comparable studies on the interaction of RNase T1 with RNA and small guanine ligands.


Studies on human tRNA. I. The rapid, large scale isolation and partial fractionation of placenta and liver tRNA. A procedure for the large scale isolation of mammalian tRNA has been applied to the isolation of several grams of human liver, human placenta, rabbit liver and rat liver tRNA. This procedure entails an initial grinding of the tissue in phenol-sodium acetate at acidic pH, followed by DEAE cellulose chromatography. Procedures are also described for analysis of the purified tRNA on the basis of size, using controlled pore glass bean columns. In addition, the acceptor activity of isolated tRNAs has been determined using both the heterologous and homologous synthetases. The chromatographic profile of individual isoaccepting species using BD cellulose chromatography is shown and the 3' terminal nucleoside content was also determined. The methods described now make it feasible for large scale studies of mammalian tRNA enabling us to better understand the relationships between the structure of mammalian tRNA and its many diversified functions.


Genetic heterogeneity in familial hypercholesterolemia: evidence for two different mutations affecting functions of low-density lipoprotein receptor. Studies in cultured fibroblasts from patients with the clinical syndrome of homozygous familial hypercholesterolemia have disclosed two different mutations affecting the functions of the low density lipoprotein receptor. One of these mutations, described previously, results in a functionless receptor that does not bind low density lipoproteins. In the cells of six patients who appear to be homozygous for this mutant allele, i.e., receptor-negative homozygotes, low density lipoproteins neither suppress hydroxymethylgultaryl-CoA reductase (NADPH) [mevalonate:NADP+ oxidoreductase (CoA-acylating) EC 1.1.1.34] activity nor stimulate cellular cholesterol esterification, even when examined in the presence of concentrations of lipoprotein 500 times higher than those cells. The second type of mutation, described herein, results in a receptor that has a reduced but not absent function. Fibroblasts from three subjects who possess this mutation, i.e., receptor-defective homozygotes, show partial suppression of the same enzyme activity and a detectable increase in cholesterol esterification capacity in the presence of high levels of low density lipoproteins. It was calculated that their degree of function could be achieved if they possessed only about 10% of the normal binding of low density lipoprotein. This level of binding was too low to be reliably detected by the 125-I-labeled low density lipoprotein binding assay. The finding of a second class of mutant cells in which a defect in low density lipoprotein binding is associated with simultaneous defects in both suppression of hydroxymethylglutaryl-CoA reductase activity and stimulation of cholesterol ester formation provides further evidence for the coordinate control of these two processes by the low density lipoprotein receptor.


[Conditions of dextranase formation by Penicillium funiculosum 15]. The influence of the following factors on the synthesis of extracellular dextranase by Pen. funiculosum 15 has been studied: the quantity and age of the inoculum, pH of the cultivation medium, stimulants of the microbial growth, cultivation temperature and time.  The optimal amount of dextranase has been found to form under the following conditions: inoculum--3 day mycelium constituting 4%, cultivation time--4 to 7 days, temperature--28 to 29 degrees C, initial pH of the medium--6.0.


Protein kinase activation as an early event in the trans-synaptic induction of tyrosine 3-monooxygenase in adrenal medulla. An increase of cAMP/cGMP concentration ratio is the earliest stimulus-coupled biochemical change that has been measured in the adrenal medulla during the trans-synaptic induction of tyrosine 3-monooxygenase [EC 1.14.16.2; L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating)]. In adrenal medulla of rats receiving reserpine alone (16 mumol/kg intraperitoneally) or reserpine and propranolol (40 mumol/kg intraperitoneally 30 min before reserpine), or exposed to 4 degrees for 4 hr, the extent and duration of the increase of the cAMP/cGMP concentration ratio exceeds the critical value that is required to activate the protein kinases (EC 2.7.1.37; ATP:protein phosphotransferase). Gel filtration experiments indicate that during this activation, the catalytic subunit of the protein kinase (low-molecular-weight enzyme) is released from the holoenzyme. The activation of protein kinase lasts longer than the increase in the cAMP/cGMP concentration ratio and appears to be an obligatory early event that mediates the increase of tyrosine monooxygenase synthesis. The trans-synaptic induction of the monooxygenase in adrenal medulla appears to be due to an increased synthesis of the enzyme;the rate for monooxygenase degradation is proportional to the number of enzyme molecules that are present at various stages of the induction process.


[Specificity of the degradation and synthesis of dinucleoside monophosphates by RNAase C2 of Asp. clavatus]. The ability of RNAase E2 to degradate dinucleoside moniphosphates and to form internucleotide bonds was studied. The compounds of the GpN type were found to be a good substrate for RNase C2. The pH optimum for GpC was 5.5 (acetate buffer) and the temperature optimum was 30 degrees C. The values of Km and Vmax on GpC, GpA, GpG and GpU were determined. The affinity of the substrates for the enzyme decreased in the sequence GpC greater than GpG greater than GpA GREATER THAN GpU. RNase C2 catalyze the synthesis of GpC and GpU. The yield of GpC amounted to 60% and that of GpU was 35%. These data indicate that RNase C2 FROM Asp. clavatum is guanyl ribonuclease (EC 3.1.4.8.).


[Respiratory-renal regulation of acid-base equilibrium disorders in patients with diabetes mellitus]. The effects of ration on postprandial serum glucose and insulin were determined in 12 lactating Holstein cows. Six were fed a high grain ration of 15% hay and 85% concentrate (dry basis) and the other six a control ration of 55% corn silage, 10% hay, and 35% concentrate. High grain feeding increased flucose and insulin at all hours postfeeding as compared to control cows. In the cows fed high grain, glucose increased from 63.3 to 72.2 mg/100 ml and insulin from 19.2 to 25.6 muunits/ml serum just before feeding to 3 h postfeeding. Values for 2, 3, and 4 h samples were greater than for other sampling times. Serum glucose was 55.5 mg/100 ml at 1 h in control cows which was above other samples. Serum insulin followed a pattern similar to glucose in controls but was not significantly different with time. The blood changes due to high grain feeding are probably related to low milk fat production.


Activation by cyclic 3':5'-adenosine monophosphate of tyrosine hydroxylase in the rat brain. Membrane-permeable derivatives of cyclic AMP (cAMP) produced concentration-dependent increases in activity of tyrosine hydroxylase (L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2) in membrane-limited nerve endings (synaptosomes) prepared from three regions of rat brain. Increased hydroxylation occurred even after preincubation and removal of dibutyryl cyclic AMP. In all brain regions, the hydroxylation of phenylalanine and tyrosine was increased, but dibutyryl cAMP had little effect on activity of tryptophan hydroxylase, no effect on aromatic amino-acid decarboxylase, on uptake of tyrosine or phenylalanine, uptake or efflux of dopamine, or distribution of hydroxylase between cytoplasmic and particulate components of the synaptosomes. Dibutyryl cAMP decreased inhibition of catecholamine synthesis in synaptosomes by dopamine and apomorphine. In a soluble preparation of striatal tyrosine hydroxylase, activity was increased by addition of lower concentrations of cAMP or dibutyryl cAMP than with unbroken nerve endings, when subsaturating concentrations of tyrosine and cofactor were employed, while butyrate, chloride, 5'-AMP, ADP, ATP, and cyclic GMP had no activating effect. Increased activity of soluble tyrosine hydroxylase was reflected in increased affinity (Km) for substrate and cofactor and decreased affinity (Ki) for inhibitory end-product (dopamine), suggesting a change in the physical-chemical state of the enzyme or an activator molecule. Cyclic AMP may activate tyrosine hydroxylase during periods of increased neuronal activity.


Adenine formation from adenosine by mycoplasmas: adenosine phosphorylase activity. Mammalian cells have enzymes to convert adenosine to inosine by deamination and inosine to hypoxanthine by phosphorolysis, but they do not possess the enzymes necessary to form the free base, adenine, from adenosine. Mycoplasmas grown in broth or in cell cultures can produce adenine from adenosine. This activity was detected in a variety of mycoplasmatales, and the enzyme was shown to be adenosine phosphorylase. Adenosine formation from adenine and ribose 1-phosphate, the reverse reaction of adenine formation from adenosine, was also observed with the mycoplasma enzyme. Adenosine phosphorylase is apparently common to the mycoplasmatales but it is not universal, and the organisms can be divided into three groups on the basis of their use of adenosine as substrate. Thirteen of 16 Mycoplasma, Acholeplasma, and Siroplasma species tested exhibit adenosine phosphorylase activity. M. lipophilium differed from the other mycoplasmas and shared with mammalian cells the ability to convert adenosine to inosine by deamination. M. pneumoniae and the unclassified M. sp. 70-159 showed no reaction with adenosine. Adenosine phosphorylase activity offers an additional method for the detection of mycoplasma contamination of cells. The patterns of nucleoside metabolism will provide additional characteristics for identification of mycoplasmas and also may provide new insight into the classification of mycoplasmas.


Circadian rhythm of tyrosine hydroxylase induction by short-term cold stress: modulatory action of glucocorticoids in newborn and adult rats. The trans-synaptic induction of tyrosine hydroxylase [tyrosine 3-monooxygenase; EC 1.14.16.2, L-tyrosine, tetrahydropteridine: oxygen oxidoreductase (3-hydroxylating)] in adrenal medulla and sympathetic ganglia by short-term (1-2 hr) cold stress (4 degrees) exhibits a circadian rhythm which seems to be causally related to the diurnal changes in adrenal glucocorticoid synthesis. In induction is maximal during the morning hours, when plasma corticoid concentrations (reflecting corticoid synthesis in the adrenal cortex) are minimal. In contrast, initiation of tyrosine hydroxylase induction in sympathetic ganglia is only possible in the afternoon. These observations suggest that tyrosine hydroxylase inducibility in the adrenal medulla is optimal during periods of low corticoid synthesis (the adrenal medulla is exposed to excessively high corticoid concentrations directly originating from the adjacent cortex), whereas in sympathetic ganglia an induction is only possible during the period of high plasma corticoid concentrations. This assumption is supported by the observation that in the first postnatal weeks, when the pituitary--adrenocortical system is not yet operating and plasma corticoid concentrations are low, initiation of tyrosine hydroxylase induction in the adrenal medulla is possible at any time of the day, whereas in sympathetic ganglia it is not possible at all. However, after administration of glycocorticoids initiation of tyrosine hydroxylase induction by short-term cold stress is also possible in newborn animals and in adults during the morning hours. The importance of glucocorticoids as modulators for the initiation of trans-synaptic tyrosine hydroxylase induction can also be deduced from the observation that in sympathetic ganglia kept in organ cultures and induction of the hydroxylase by cholinomimetics is only possible when glycocorticoids are added to the culture medium.


Chemical nature of bioluminescence systems in coelenterates. Analysis of substances involved in light-emitting reactions among bioluminescent coelenterates has revealed a pronounced uniformity in the structural features of initial reactants, i.e., "luciferins" and photo-protein chromophores, as well as the light-emitter product. This product is structurally identical among the different classes of coelenterates: Hydrozoa (the jellyfish, Aequorea), Anthozoa (the sea cactus, Cavernularia; sea pansy, Renilla; and sea pen, Leioptilus), and very likely also the Scyphozoa (the jellyfish, Pelagia). In each of these instances the reaction product, namely, 2-(p-hydroxy-pnenylacetyl)amino-3-benzyl-5-(p-hydroxyphenyl) pyrazine, is the actual light-emitter, whether it occurs in a Ca2+-triggered photoprotein type of luminescence, or in a "luciferin-luciferase" type. The evidence indicates that in certain coelenterates, e.g., Cavernularia, these two types are equally significant, whereas in others (Renilla and Leioptilus) the "luciferin-luciferase" type predominates over the Ca-triggerable photoprotein type, and finally that only the photoprotein type functions in the luciferaseless jellyfish, Aequorea. In all instances investigated, the structure of the light-emitter prior to the luminescence reaction appears to be essentially the same as that of the chromophore of unreacted aequorin. The product of the luminescence reaction is absent in extracts of non luminous species. However, a product very similar to that of luminescent coelenterates occurs also in representatives of other phyla, including the cephalopod molluscs, e.g., the "firefly squid" Watasenia and probably various ctenophores as well.


Interaction of glyoxal and methylglyoxal with biogenic amines. Glyoxal and methylglyoxal interact with biogenic amines and form biologically active free radicals. Electron spin resonance absorption of the radical at room temperature is characterized by a signal at g equals 2.004 with peak-to-peak width of 29 G. An optical absorption at 400 nm with molar absorptivity of 23,000 accompanies the formation of the radical. The dry powdered preparation of the same reaction, which is considered to be the seconardy product, gives an electron spin resonance signal much narrower and 1/200 in intensity compared with the one in solution. Similarly the 400 nm absorption intensity is 1/8 that of the primary product. Possible biological significance of the primary and the secondary product, in relation to muscular dystrophy and photophosphorylation, is discussed.


A Quantitative study of histamine H2-receptor bockade by burimamide in isolated artica. The onset of burimamide inhibition of histamine stimulation of rabbit atria is rapid, and a near steady-state blockade occurs at approximately 15 min ( larger than or equal to 90% complete). The blockade is reversible but requires several washings suggesting the disassociation is slow. The administration of histamine may accelerate the decay of the burimamide effect. Reciprocal plots (rate response versus histamine concentration) of dose-response curves are linear for both rabbit and guinea pig atria. In the presence of low concentrations of burimamide; (2.4  times 10-5 M), the displacement of curves suggests a competitive type of inhibition both for rabbit and guinea guinea pig atria. The apparent association constants calculated from these curves are: K1 (rabbit) 3.7 times 10-6M and K-1 (guinea pig) 6.7 times 10-6M. These results for guinea pig atria are in satisfactory agreement with the value obtained in another laboratory (2). At higher concentrations of burimamide, inhibition curves showed distinct evidence of departure from competitive character for both guinea pig and rabbit atria.


Serum antitrypsin synthesis by the isolated perfused rat liver. The isolated perfused rat liver synthesizes antitrypsin activity in a linear fashion as long as 24 hr. The rate of synthesis may be ten times the rate necessary for physiologic levels in vivo. These data are compatible with the liver as the principal site of synthesis of serum antitryptic activity in the rat. The antitrypsin activity of the rat perfusate resembles that of normal human plasma in liability to heat (56 degrees) and to acid (below pH 6) and in apparent molecular size (elution from Sephadex G-200).


Complement in graft versus host disease: IL Depletion of complement components during a systemic graft versus host reaction in the rat (38499). Serum complement (C) and C components were examined during a systemic graft versus host (GVH) reaction in the rat. In our series of experiments (Lewis times Brown Norway) F-1 hybrid rats (60-80g) were given 200 times 10-6 or 400 times 10-6 Lewis spleen cells intravenously. Clinical GVH disease appeared 5-7 days after cell injection. Five of six rats in the experimental groups had a fall in levels of serum C2 (20-76%) and C4 (75-98%). Only one of six rats in the control group had a significant fall in C components. In a subsequent experiment (Fisher 344 times Brown Norway) F-1hybrid rats (60g) were given 400 times 10-6 Fischer 344 spleen cells or 200 times 10-6 Fischer  344 Ficoll-Hypaque separated spleen lymphocytes. Clincal  GVH disease in this instance appeared on day 10. As in the previous experiments C2 and C4 fell markedly, 20-60% and 60-8-%, respectively, from baseline titers. The control groups did not have a significant fall in C2 or C4. Further examination showed reduction in C3, C5, C6,AND C8 suggesting a sequential activation of the C system via the classical pathway. We have postulated that the cells undergoing blast transformation may be activating the C system through membrane changes during the GVH reaction. Furthermore, the deficiency of C AND C components during GVH disease may contribute to the increased susceptibility of the host to infection and sepsis.


Inhibition of Hageman factor, plasma thromboplastin antecedent, thrombin and other clotting factors by phenylglyoxal hydrate (38500). Exposure of purified Hageman factor (HF, Factor XII) to phenylglyoxal hydrate (PHG), an agent reacting with arginine residues in protein, inhibited its coagulant properties upon subsequent exposure of negatively charged agents. Once HF had been exposed to kaolin or ellagic acid, however, subsequent addition of PHG was much less inhibitory. PHG had no effect upon the ability of HF to bind to negatively charged surfaces. PGH also inhibited preparations of activated PTA (Factor XI) and thrombin, and, when incubated with plasma, reduced the titer of coagulable fibrinogen, PTA Christmas factor (Factor IX), antihemophilic factor (Factor VIII), Factor VII, Stuart factor (Factor X), proaccelerin (Factor V) and prothrombin (Factor II), and to a lesser degres, HF.


Response of muscular and cutaneous vessels to physiologic stimulation of chemoreceptors (38505). Experiments were performed to determine whether physiologic stimulation of carotid chemoreceptors produces different responses in blood vessels of skin and muscle. Carotid chemoreceptors of anesthetized dogs were stimulated with hypoxic and hypercapnic blood and responses were observed in the isolated, perfused gracilis muscle and hindpaw. Chemoreceptor stimulation produced vasoconstriction in the muscle and vadodilatation in the paw (a predominantly cutaneous vascular bed). Responses to hypoxia without hypercapnic acidosis tended to be less pronounced. The study indicates that physiologic stimulation of carotid chemoreceptors produces contrasting responses in different vascular beds.


Effect of severe anoxia on the permeability of gastric mucosa (38517). The effect of severe anoxia produced by gassing with 100% nitrogen on gastric mucosal permeability and hydrogen ion back diffusion was investigated using an in vitro preparation of rabbit fundic gastric mucosa mounted in an Ussing chamber. Permeability was estimated by determination of the flux of the water soluble, nonlipidsoluble molecule erythritol from the mucosal to serosal solution. The flux rate across normal tissue was 2.80 plus or minus 0.41 pmoles/cm-2/sec, and rose to 3.32 plus or minus 0.57 pmoles/cm-2/sec after 2 hr of severe anoxia. Hydrogen ion ack diffusion was measured by determining with a pH stat the amount of hydrogen required to maintain the [H+] of the mucosal solution at 0.1, 1.0, 2.0 and 3.2 mEq/L in both normal and anoxic tissues. One hour of anoxia increased the back diffusion of H+, but the changes only became statistically significant at all pH values after 1.5 hr. Anoxia did however cause an immediate fall in potential difference to zero, and a rise in resistance which after 30 min fell progressively to preanoxic levels. Anoxia produces a small increase in gastric mucosal, permeability, an effect which may be enhanced by other factors.


Role of vasoactive substances in active hyperemia in skeletal muscle (38520). A prolonged, 2-hr period of exercise hyperemia in the canine gracilis muscle was associated with initial increases in the arteriovenous differences for potassium, hydrogen and osmolality. However, that for hydrogen decreased and those for potassium and osmolality became negligible by the 120th min while blood flow remained elevated. Thus, potassium and osmolality do not appear to participate importantly in the maintenance of exercise hyperemia in canine gracilis muscle. A bioassay muscle did not respond with comparable dilation when submaximal, graded levels of exercise hyperemia were induced in an upstream, donor muscle but did respond more comparably in terms of magnitude and time course when the exercise was more severe. Thus, stable vasoactive substances may not entirely account for exercise hyperemia and the study fails to provide evidence that the capillary acts as a significant barrier to the vasoactive substances.


Metabolism of octanoate and its effect on glucose and palmitate utilization by isolated fat cells. Octanoate is avidly incorporated into triglycerides by isolated rat adipocytes in the presence of glucose via direct esterification without prior beta-oxidation to acetyl CoA.  This was shown by separation of the products formed from (1-14C) octanoate into lipid classes using Florisil columns, and after alkaline hydrolysis of the triglyceride fraction, by cochromatogrpahy with authentic fatty acids on reverse-phase Celite columns. The relative contribution of (U-14C) glucose and (1-14C) octanoate to triglyceride synthesis and CO2 formation were studied under a variety of conditions.  Concentrations of octanoate below 0.5 mM have a stimulatory effect on the conversion of (U-14C) glucose to CO2, triglycerides and esterified fatty acids.  However, a marked depression of fatty acid synthesis from (U-14C) glucose was observed in the presence of millimolar concentrations of octanoate.  Octanoate had no effect on the esterification of palmitate, but palmitate strongly depressed the ability of rat adipocytes to esterify octanoate.


Evidence for beneficial effect of intravenous glucose on the hemodynamic response to acute asphyxia. Anesthetized rabbits were subjected to two 4-min periods of asphyxia with a 15-min recovery period intervening. During the recovery period animals received an iv infusion of either isotonic glucose or mannitol. Results indicated that glucose had a beneficial effect on systolic blood pressure during the second period of asphyxia. A direct metabolic action of glucose on the myocardium is favored as the explanation, but other possibilities include peripheral or neurohumoral effects.


Lipoprotein lipase activity in bovine aorta. A lipoprotein lipase in the bovine arterial wall has been identified and partially characterized. The enzyme has a Km apparent of 1 mM for triolein in a phosphatidylcholine stabilized emulsion. The lipase was stimulated 20- to 30-fold by the addition of heated rat plasma to the assay medium. The activity exhibited a pH optimum at 8.6. Protamine sulfate (1.0 mg/ml) inhibited the activity by 50%, whereas 1.4 M sodium chloride inhibited by 85%. Sodium fluoride, an inhibitor of the hormone-sensitive lipase, had no effect on the activity. Additions of low concentrations of heparin or Ca-2+ to the enzyme caused a slight stimulation of the lipolytic activity. A crude sectioning of the aorta revealed specific activity of lipoprotein lipase to be highest at the endothelial side of the artery.


Effect of exercise on response of liver lipogenic enzymes to a high fructose diet. Meal-fed Long-Evans rats fed a high fructose diet and exercised for 2-hr daily on a treadmill for three days had lower levels of several hepatic lipogenic enzymes (acetyl CoA carboxylase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, malic enzyme and citrate cleavage enzyme) than did sedentary rats pair-fed the diet. Accumulation of triglycerides in plasma following ingestion of a fat-free, high fructose meal and injection of Triton WR-1339, an inhibitor of plasma triglyceride clearance, was not significantly different in the two groups of animals. All of the hepatic lipogenic enzymes measured, with the exception of citrate cleavage enzyme, attained similar levels in the runners as in the controls after 5 days on the high fructose diet. Thus the exercise appeared to affect the time course of the increase in the levels of activity of most of the lipogenic enzymes but not the final steady state levels attained.


Gastric antisecretory effect of 15(R)-15-menthyl PGE2, methyl ester and of 15(S)-15-methyl ester. Gastric juice was collected from gastric pouches in dogs stimulated with histamine. 15(R)-15-methyl PGE2, methyl ester inhibited gastric secretion in dogs when given orally, but was almost inactive when given intravenously, whereas 15(S)-15-methyl PGE2 methyl ester was active by both routes. When given directly into the small intestine (intrajejunally), the 15(S) was active and the 15(R) was inactive. The 15(R), diluted in acid and administered intrajejunally, became active in inhibiting gastric secretion. When the 15(S) was diluted in acid and administered intrajejunally, it lost half of its activity. When each analog was incubated in an acid medium, each was epimerized to give approximately a 1:1 mixture of both 15(R) and 15(S). Incubation of the 15(R) in pH 3 buffer resulted in only a trace of formation of 15(S). These results explain why the 15(R) is active orally but not intrajejunally. When given orally, the low pH of gastric secretion epimerizes much of the 15(R) into the 15(S),which is active by any route. The degree of acidity of gastric contents may determine whether the 15(R) will exert an antisecretory effect.


Unexpected beta adrenergic effects of the antitumor agent, cyclocytidine, on rat salivary glands. In addition to its potent antileukemic properties, cyclocytidine has a sialogogue action that depends on stimulation of beta adrenergic ereceptors of salivary glands. Furthermore, when chronically administered (for 3 days), cyclocytidine caused enlargement of parotid and submaxillary glands and heart that resembled the hypertrophy caused by chronic isoproterenol administration. The salivas evoked by cyclocytidine also closely resembled those evoked by isoproterenol, and were extremely viscous, and high in K+, (121 plus or minus 5.6, for submaxillary, and 42 plus or minus 2.9, for parotid), low in flow rate (0.007 mg/min times mg) and parotid saliva contained high concentrations of amylase (805 plus or minus 33 mg/mg gland). Cyclocytidine also caused marked emptying of parotid gland amylase. The cyclocytidine-induced salivary flow and gland emptying of amylase were prevented for 90 min when propranolol (but not dibenzyline or atropine) was administered prior to injection of the cyclocytidine. In addition, when the superior cervical ganglion was acutely removed, administration of cyclocytidine elicited salivary flow from the denervated as well as the innervated glands. These findings suggest that cyclocytidine does not affect salivary glands through indirect central or ganglionic actions. Cyclocytidine action does not exclusively involve beta receptors, since even in the presence of propranolol, secretory flow was evident after 90 min but when dibenzyline was given with the propranolol, complete blockade of cyclocytidine-stimulated saliva was effected. The dominant effect is, however, a beta adrenergic one. The undesirable side effects of cyclocytidine (parotid pain, postural hypotension, and cardiac hypertrophy) probably stem chiefly from its beta adrenergic properties and might be eliminated (or at least modified) by administration of propranolol with the cyclocytidine.


The effect of chlorpromazine on some properties DNA in solution. The effect of chlorpromazine [2-chloro-10-(3-dimethylaminopropyl)-phenothiazine] on calf thymus DNA has been investigated by spectrophotometric, equilibrium dialysis, thermal denaturation, sedimentation and viscosity methods. The absorption spectra of DNA undergo two important changes upon binding to chlorpromazine, namely, the displacement of peaks to longer wavelength (ranging from 5-8 nm) and a decrease in the optical density. The extent of binding of chlorpromazine to native calf thymus DNA, AS MEASURED BY SPECTROPHOTOMETRIC METHOD, IS DECREASED WITH INCREASING SODIUM CHLORIDE Concentration. A curvature in the Scatchard plot suggests two types of binding processes. Chlorpromazine decreases the optical density at higher temperatures without affecting the Tm of DNA. In its presence, the absorption spectra of purine deoxynucleosides (dA, dG) and of deoxynucleotides (dAMP, dGMP) are modified, i.e., the maxima are displaced to longer wavelength (ranging from 5-17 nm) and there is a general decrease in the optical density. No such effect is observed with pyrimidine deoxynucleosides (dC, dT) and deoxy-nucleotides (dCMP, dTMP). A combination of electrostatic binding of the amino group of chlorpromazine sidechain with the negative phosphate groups of the DNA and a partial insertion of either of its two phenyl rings between the nucleotide base pairs of the DNA plus the binding caused by mutual interaction between different chlorpromazine molecules at higher concentration is proposed as a probable mode of binding of chlorpromazine to DNA.


The cross-foot flap.

The cross-foot flap. Reconstruction for losses of the highly specialized skin on the weight-bearing and friction-resistant areas of the foot remains a challenge to the ingenuity of reconstructive surgeons. Although the use of skin from a plantar non-weight-bearing area was described by Mir y Mir 20 years ago, no other reports using the method and emphasizing its advantages have appeared in the literature. On the basis of two cases, both being failures after the use of other methods, we commend the use of a cross-instep flap.


The effect of angiotensin-II during ventriculography in dogs with normal coronary arteries. Left ventriculography was performed with and without angiotensin-II in dogs with normal coronary arteries. Concomitant administration of angiotensin significantly attenuated the myocardial depression associated with ventriculography. The beneficial effect of angiotensin may be due to its ability to maintain aortic diastolic pressure and thus flush the contrast material from the myocardium more rapidly, at least in animals without imposed coronary stenosis.


Dental health of Louisiana residents based on the ten-state nutrition survey. The dental health status of 4,006 residents of Louisiana was analyzed, based on data in the 1968-70 Ten-State Nutrition Survey funded by the U.S. Government. These data were based on examinations of census districts in which the average per capita income was in the lowest quartile for the nation. A considerable variation in the prevalence of dental diseases was found among the Louisiana residents according to age. The females examined had a slightly higher DMF (decayed, missing, and filled permanent teeth) score, a lower OHI (oral hygiene index) score, and a slightly lower PI (periodontal index) score than did the males. The dental caries attack rate did not vary much by race, but the whites examined had received a much greater amount of dental care than had their black counterparts. The OHI scores of the blacks were higher than those for the whites in both the debris and calculus components. The PI scores were higher for the blacks than for the whites. More white persons than blacks were edentulous; this result, however, tends to confirm the observation of increased dental care in white persons. The percentages of persons with periodontal disease and periodontal pockets were considerably higher among persons with incomes below the poverty level, and a greater percentage of blacks had incomes below that level. The data thus apparently indicate that the major determinants of dental health status in Lousiana are age and level of income; race appears to be the major determinant of the amount of dental care received.


Differing responses to hypercapnia and hypoxia following pneumotaxic center ablation. The respiratory responses of 21 cats were examined upon exposure to hypercapnia and isocapnic hypoxia. Animals having bilateral electrolytic lesions localized in the pontile pneumotaxic center exhibited hypercapnia-induced minute volumes which were significantly less than those of unlesioned control cats. The hypoxia-induced minute volumes of pneumotaxic lesioned animals, examined at isocapnic alveolar gas partial pressures, were likewise significantly less than control animals at end-expired oxygen partial pressures (PAO2) in excess of 65.0 mm Hg. At PAO2 levels below 65.0 mmHg. the minute volume of experimental animals rose sharply and became statistically indistinguishable from that of the unlesioned cats. The placement of control brain stem lesions typically produced no significant alterations in the respiratory responses to hypoxia or hypercapnia. It was concluded that the pneumotaxic center constitutes an integral component of the central chemoreceptor CO1-H+ CONTROLLING SUBSYSTEM. The concept of differing anatomical sites within the brain stem serving integrative functions for central chemoreceptor and peripheral chemoreceptor afferent stimuli is also supported.


Determination of mean whole body intracellular pH  in unanesthetized dogs. In order to determine mean whole body pHi in unanesthetized dogs, assumptions on the urinary and intestinal excretion of DMO, the total loss of an injected single dose of [14C] DMO, and the distribution kinetics of DMO were tested experimentally. Urinary excretion of DMO was almost negligible. The best assumption on the total loss of DMO was based on the exponential decay observed over a period of 1 to 4 weeks. The biological half-life of DMO was 5 days, the time constant being --0.14 d-1. The extracellular distribution of DMO was considered to equal that of [3H] inulin. Between 1 and 7 hours after an injection of inulin in nephrectomized dogs the distribution volume increased linearly from 16% of the body weight after 2 hours to 21% after 6 hours. Based on these experimental results, pHi was determined in 16 unanesthetized dogs. 120 min after the injection of DMO pHi was 7.05 and 430 min after the injection pHi was 7.11. It is concluded that the assumption made allow the estimation of pHi in unanesthetized dogs over a period of 1 to 7 hours.


Intracellular pH in unanesthetized dogs during panting. Intracellular pH, arterial blood gases and several plasma enzymes were estimated in unanesthetized dogs during a 3-hour exposure to 30 degrees C/50% relative humidity, and 40 degrees C/50% relative humidity. No change occurred during mild heat stress, whereas during severe heat stress a profound respiratory alkalosis developed together with an increase in intracellular pH from 7.03 to 7.29. Most plasma enzymes increased by about 300% or more. In spite of extreme panting body temperature rose to 42.2 degrees C. Exposure to 40 degrees C/50% relative humidity with 4% CO2 in the climatic chamber inhibited the respiratory alkalosis and the increase of plasma enzymes. Though the panting frequency was lower the ventilatory heat dissipation was more efficient. Body temperature rose to only 39.8 degrees C. It is concluded that the intracellular buffering is not able to prevent marked changes of the intracellular pH during panting.


Vitamin B12-binding proteins in human gastric mucosa. General pattern and demonstration of intrinsic factor isoproteins typical of mucosa. Extracts of human stomach mucosa were shown to contain immunoreactive intrinsic factor and small amounts of R protein and transcobalamin II. In gel filtration the mucosal vitamin B12-intrinsic factor complex behaved as though its molecular weight were smaller than the corresponding complex in gastric juice. In isoelectric focusing both the gastric juice and mucosal vitamin B12-intrinsic factor complexes resolved into numerous isoproteins. These findings were verified by DEAE-cellulose chromatography. The mucosal intrinsic factor isoprotein pattern contained, in addition to the isoproteins found in gastric juice, components with higher isoelectric points -- that is, pH 5.73-6.64.


Skeletal muscle metabolites in patients with cardiogenic shock or severe congestive heart failure. Skeletal muscle metabolite concentrations were determined in 19 patients in either cardiogenic shock or severe left ventricular failure by obtaining a needle biopsy specimen of lateral thigh muscle. Evidence of anaerobic skeletal muscle metabolism was found in both patient groups with the greatest lactate accumulation and most severe high-energy phosphate depletion present in the patients in cardiogenic shock. The skeletal muscle lactate accumulation was most pronounced in the patients that died. Blood lactate values did not absolutely predict skeletal muscle lactate concentrations in those patients in whom skeletal muscle lactate concentrations were the highest. The patients in cardiogenic shock and severe left ventricular failure who survived demonstrated a reduction in skeletal muscle lactate levels and a restoration of high-energy phosphates over several days which correlated with clinical and hemodynamic improvement.


Flexible fiberoptic bronchoscopy with general anesthesia in the poor-risk patient. A study is presented of seven poor-risk patients who had bronchoscopy with a flexible fiberoptic bronchoscope and balanced general anesthesia. The cardiorespiratory status, as evidenced by arterial blood gas determinations, electrocardiographic findings, and blood pressure measurements, was improved and stabilized in all patients. Flexible fibeoptic bronchoscopy, combined with general anesthesia, has proved to be a reliable and safe procedure useful for both diagnosis and treatment in poor-risk patients.


Evaluation and management of the dizzy patient. Evaluation and management of the dizzy patient remains frustrating to both the patient and physician. Numerous disorders may induce dizziness; these include not only inner ear disoders but also various central nervous system, ocular, and general systemic disturbances. Since dizziness has many variations, the subtle nuances the symptom may manifest must be explored throughly. Similarly, a consistent approach to the patient's physical and larboratory examination must be taken to understand the pathophysiology of the dizziness. This includes comprehensive auditory and vestibular evaluation, complete neurologic and ophthalmologic examination, and laboratory evaluation for latent or manifest systemic disease. The management of dizziness and vertigo is largely symptomatic. Certain exceptions exist where specific medical and surgical approaches may be beneficial, but the limitations of such treatment must be appreciated.


Immunologic reconstitution in man--present status. Recent advances in immunobiology have shed new light on our understanding of the essential role of immunity as it relates to body economy. Immunity, once thought to be the primary defense mechanism against microbial infection, appears to have a much broader function--recognition and elimination of foreign bodies and preservation of the integrity of the individual. As our understanding of the pathophysiology of the immune system became more clear, immunologic reconstitution emerged as a new, promising mode of treatment for a variety of diseases with immunodeficiency. Bone marrow transplantation, thymus transplanation, transfer factor therapy, infusion of leukocytes, BCG vaccination, and other specific or nonspecific immunostimulants have been tried, with dramatic beneficial results in some instances. Although still in its infant stage, this form of treatment appears to have great potential and wide application in the prevention and treatment, not only of primary immunodeficiency, but also of many other diseases such as cancer, the so-called autoimmune diseases, and even aging.


Adenosine triphosphatase in the embryonic development of the loach. The ATPase (ATP-phosphohydrolase) activity of homogenates of eggs of the loach Misgurnus fossilis L. was investigated at various stages of development. Mg-2+- and Ca2- minus 2+-stimulated ATPases are the predominant forms of ATPase activity in the egg, and their level is almost constant during development. The loach egg also contains (Na-+--K-+)-dependent ATPase, which is maximally active at pH 6.85 and at a ratio Na-+:K-+ Equals 5:1. This activity is negligible or absent in homogenates of unfertilized eggs, increases during cleavage, but disappears at the end of the period of cleavage. After this, the (Na-+--K-+)-ATPase activity increases all the way up to the end of the period studied (the gastrula stage)mthe results are discussed in connection with the literature data on changes in ionic homeostasis and other characteristics during early embryogenesis.


Ventricular function in experimental hemorrhagic shock. Hemorrhagic shock was induced in 20 spontaneously breathing adult greyhounds by lowering the mean arterial pressure to 40 millimeters of mercury. In the first group of six dogs, reinfusion was carried out without delay; in a second group of six dogs, hypovolemia was continued for two hours, during which time the arterial pressure was permitted to rise in response to intact cardiovascular reflexes; in a third group of eight dogs, the mean arterial pressure was artificially maintained at 40 millimeters of mercury for two hours, initially by further bleeding. In all dogs in the latter group, take-up of blood from the reservoir was required during the second hour to maintain the arterial pressure, this being indicative of irreversible shock. In two of this group, fatal arrhythmias developed during reinfusion. All three groups showed evidence of ventricular dysfunction during and immediately after reinfusion, as indicated by disproportion between left ventricular stroke work and left ventricular end diastolic pressure, these data being used to construct ventricular function curves. Measurement of dP/dt maximum suggested that this dysfunction was due to impairment of myocardial contractility. The first two groups recovered normal function within one hour; the third group failed to have such a recovery. Evidence indicates that generalized tissue hypoxia, in addition to myocardial hypoxia, is important in the cause of cardiac dysfunction in irreversible shock.


Adrenergic mechanisms in the cephalic and cerebral circulations of the subhuman primate. Effects of circulating adrenergic amines on the cerebral circulation remain contraversial. Common carotid (CCF) and internal carotid (ICF) arterial flows were determined electromagnetically in eight lightly anesthetized baboons to evaluate alterations in the cephalic and cerebral vascular beds, respectively. Epinephrine (E), norepinephrine (NE), phenylephrine (PE), and isoproterenol (I) were injected randomly in doses of 10-3, 10-2, 10-1, and 1 mug (base) per kilogram into each carotid artery. Measurements were repeated in four animals after alpha-adrenergic blockade with phenoxybenzamine and in another four animals after beta-adrenergic blockade with propranolol. Baseline CCF was 75 plus or minus 10 (S.E.M.) ml. per minute and ICF was 58 plus or minus 8 ml. per minute. Significant (p smaller than 0.05) CCF changes without arterial pressure alterations occurred with 10-1 mug per kilogram doses. Alpha blockade significantly (p smaller than 0.05) attenuated the effects of E, NE, and PE on CCF while beta blockade significantly (p smaller than 0.05) attenuated the effect of I on CCF. ICF did not change significantly (p greater than 0.05) after injection of any of the vasoactive amines, unless associated with pressure changes at the highest dose. Our data suggest the presence of alpha- and beta-adrenergic receptor sites within the cephalic circulation resulting in significant flow responses to intra-arterial adrenergic amines. The absence of responses in the cerebral circulation suggests that circulating catecholamines do not significantly influence or regulate the cerebral vasculature. In addition the data suggest that use of adrenergic agonists to alter the hemodynamics of the cerebral circulation is limited.


Positive chronotropic and inotropic effects of glucagon on the canine isolated atrium. Effects of glucagon on SA node pacemaker activity and atrial contractility were investigated in isolated canine atrium preparations which were perfused with blood led from a support dog and suspended in a bath. Glucagon at a dose from 0.1 to 10 mug was injected into the sinus node artery, which caused a marked positive chronotropic but a less inotropic effect. The positive inotropic response was simulated by atrial acceleration produced by atrial pacing. Glucagon effects were not influenced by treatment with an adrenergic beta-blocking agent, alprenolol to SQ 11725, which blocked effects of norepinephrine. It was concluded that glucagon is more effective on pacemaker activity than on atrial contractile force, and glucagon effects may not be mediated by an adrenergic beta-mechanism.


The effect of continuous dialysis on platelet preservation. Serotonin uptake and response to hypotonic shock were studied after storage of platelet-rich plasma for three days at 4, 25, and 37 C. Both properties were best maintained at 25 C. The greatly impaired serotonin uptake and hypotonic shock response of platelets stored for three days at 37 C were partly restored by resuspension of the platelets in fresh autologous plasma. No improvement was found when platelets stored at 4 C were resuspended in fresh autologous plasma. When platelet suspensions were stored for three days at 4, 25, and 37 C under continuous dialysis against plasma, the results obtained at 37 C were even better than those obtained with platelets stored at 25 C. These results indicate that if the accumulation of metabolites in the plasma milieu, which in addition to other changes results in a drop of pH, is prevented, the effective storage time of platelet concentrates can be prolonged. The use of a closed plastic dialysis system, based on the triple-bag transfusion set is suggested.


Chemical and hematological changes in stored CPD blood. Blood was drawn from ten healthy volunteer donors into citrate-phosphate-dextrose (CPD) anticoagulant and placed on the quarantine shelf of the blood bank refrigerator. Plasma dextrose, sodium, potassium, chloride, bicarbonate, GOT, LDH, and hemoglobin as well as WBC, hematocrit, MCV, MCHC, whole blood pH, and ammonia were measured on all samples initially and at one, two, seven, 14, 21, and 28 days of storage at 4 C. Whole blood lactate also was analyzed serially on five of the units. An additional 27 units of CPD bank blood (two to 21 days of age), routinely processed, handled, and stored by the blood bank, were submitted to the same analyses on the day of administration to the patient. Five of these processed units, 21 days old, were resampled at 28 days. Results of the analyses are presented and discussed. The most pronounced changes were seen for dextrose, potassium, bicarbonate, lactate, LDH, ammonia, and hemoglobin. Plasma dextrose and bicarbonate declined in concentration while potassium, lactate, LDH, ammonia, and hemoglobin rose with storage. In general, changes in the regularly processed, singly sampled bank units were greater than those observed in the specially processed, quarantined units sampled serially. This study indicates that routine transportation, processing, and handling of bank blood may lead to increased biochemical alteration.


Evaluation of bacterial contamination in blood processing. In the routine deglycerolization of frozen red blood cells, a bottle of solution intended as a final wash (0.8% NaCl, 0.2% dextrose) was found to be abnormally colored and slightly turbid. Close inspection revealed a small crack in the base of the bottle. A pure growth of Klebsiella pneumoniae was cultured. The rabbit pyrogen test on the solution was positive using 2.5 mul as was the limulus amebocyte lysate (LAL) test at a dilution of 1:10-5 for endotoxin. Studies of the growth of this organism are described and the clinical implications are discussed.


Cholinergic and adrenergic neuroreceptors in urinary tract of female dogs.  Evaluation of function with pharmacodynamics. Our preliminary pharmacodynamic studies on the lower urinary tract of adult female dogs indicate that cholinergic and adrenergic (alpha and beta) neuroreceptors in the urethra appear to coordinate the detrusor and urethral function during micturition.  Urethral resistance  measured as urethral pressure was easily altered with various pharmacologic agents.  However, only bethanechol elicited detrusor response measured as intravesical pressure.  The possible clinical usefulness of various drugs is outlined.  Our results indicate the therapeutic value of ephedrine sulfate and propranolol in stress urinary incontinence; phenoxybenzamine in neurogenic vesical dysfunction and functional outlet obstruction; phenoxybenzamine plus bethanechol in atonic neurogenic bladder; and imipramine in enuresis.


Noonan's syndrome associated with cake kidney. Noonan's syndrome is an established clinical entity.  These cases are often associated with correctable cardiac abnormalities, cryptorchism, and abnormal urinary tract.  Herein is described the first case of Noonan's syndrome associated with cake kidney.  The very high incidence of renal tract abnormalities in association with this syndrome warrants an excretory urogram in these cases for proper evaluation and management.


Treatment of cryptorchidism.  Long-term prospective study. We have presented preliminary findings on a long-term prospective study designed to (1) assess timing of orchiopexy, (2) eliminate unnecessary abdominal exploratory surgery, and (3) determine efficacy of orchiopexy on subsequent fertility and on malignant degeneration.  Some suggestions for the management of this common congenital defect can be provided, but long-term results are lacking.  A significant drop-out rate from this prospective study is expected with time; therefore, large patient numbers are needed to draw any valid conclusions at the time of postpubertal reassessment.


[Physico-chemical properties of CELO virus strains isolated in Bulgaria]. Studied were some physico-chemical properties of four CELO virus strains isolated in Bulgaria. Their behaviour to ether, chloroform and 25 per cent trypsin, and their state at 56 degrees C and at pH 3, 0 were determined through their infectious titer as obtained on 9--10-day old chicken embryos. It was found that the size of the investigated viruses is within the range of 50 to 100 mmu, they belong to the DNA-possessing group, are resistant at 56 degrees C and at pH EQUALS 3,0. They are not sensitive to ether, chloroform and trypsin. Their physico-chemical properties are fully comparable with those of the avian adenoviruses-CELO.


[The effect of transplanting cells from several tissues on the growth of snygenous sarcoma in mice]. Inhibition of syngenic sarcoma growth was observed in injection of 40 mil. of lymph node cells. Cells of the spleen and bone marrow rendered a less pronounced effect. Thymic cells proved to be less effective. No enhancement of antitumor effect was noted in simultaneous injection of thymic cells with those of the spleen and bone marrow. An addition of thymic cells to lymph node lessens reliably the tumor incidence, also conditioning a tendency to reduction of frequency of its progressive growth.


[Comparable ergometric examinations before and after administration of practolol and bunitrolol (author's transl)]. By means of a standardized, single-level ergometric load of 1.5 watt/kg body weight, the effects of a new beta-adrenergic receptor blocking agent bunitrolol (o-(2-hydroxy-3-tertiary butylamino)-propoxy)-benzonitrile) was compared with the well-known cardiovascular properties of practolol during an intraindividual therapeutic crossover trial after intravenous administration. In the absence of any side-effects, bunitrolol shows a higher degree of beta-adrenergic receptor bocking activity than practolol, with a distinct specificity towards myocardial receptors and very low cardiodepressive properties at rest. Bunitrolol caused a marked reduction (33%) in exercise-induced myocardial work effort, whilst practolol achieved a reduction of only 17% under equal conditions. Thus, the same physical work load is performed after bunitrolol more economically by decreasing both heart rate and blood pressure. The circulatory effects of an intravenous dose of 5 mg bunitrolol seems to be twice as effective as 10 mg practolol. This implies that beta-adrenergic receptor blockade by bunitrolol during work performance is four times as effective as practolol. The observed marked effect of bunitrolol on the diastolic blood pressure is discussed.


[Theoretical aspects of fighting cancer recurrence (author's transl)]. The noticeable improvement in the supply of glucose and oxygen to surviving cancer cells located far from the capillary region (primarily very slowly proliferating or non-proliferating cancer cells) can be taken as the main reason for cancer recurrence in the wake of successful tumour treatment with destruction of a high percentage of cancer cells. On the basis of theoretical and experimental research work on substrate supply, cell kinetics and therapy mechanisms in the intercapillary region, therapeutic steps are formulated which act on cancer cells situated at a greater distance from the capillaries and, therefore, against the genesis of cancer recurrence as such.


Preparation and characteristics of the structure of methoxyamine-modified f2 RNA. Treatment of phage f2 RNA with [14-C]methoxyamine under non-denaturing conditions resulted in modification of exposed cytosines only. On methoxyamine treatment in the presence of 6 M-guanidine, all cytosines were modified. Under the conditions applied, no modification of adenine base in RNA chain occurred. The structure of modified f2 RNA preparations was studied by melting and sedimentation analysis. The ratio between the modification products (N-4-methoxycytosine and N-4-methoxy-6-methoxyamino-5,6-dihydrocytosine) was determined in RNA preparations modified under non-denaturing and denaturing conditions.


Purification and some properties of arginase from human lung. Arginase from human lung has been isolated and purified about 100-fold. During the purification procedure the enzyme was stabilized by Mn2+. The molecular weight determined by Sephadex G-150 gel filtration was found to be 120 000. The enzyme is highly specific towards L-arginine. Incubation of the enzyme with EDTA for 60 min at pH 7.5 and 37 degrees C results in dissociation into inactive subunits of mol. wt. 30 000. On addition of Mn2+ ion to the inactivated enzyme, the subunits reassociate into the native form of the enzyme of mol. wt. 120 000, and the activity is restored.


Secretion of progesterone by human overies perfused in vitro. A system for the perfusion of isolated human ovaries is described. Krebs-Ringer bicarbonate buffer (pH 7.4) containing glucose, sodium lactate and pyruvate was perfused at a flow rate of 5-8 ml/min at 37 degrees C through the ovarian artery. Oxygen uptake, LDH-activity, pH and progesterone secretion were determined as parameters of viability of the perfused organ. Our results demonstrate that a relatively simple system used for perfusion was able to preserve ovarian function for at least two hours. This experimental design should not be regarded as physiological but in addition to other experimental approaches it might provide information on the physiology of the human ovary. Though lower values of progesterone secretion than in vivo were found, a correlation of secretion and functional stage of the ovaries could be demonstrated.


Studies on 17beta-hydroxysteroid dehydrogenase in human endometrium and endometrial carcinoma. Kinetic parameters, substrate specificity and stability of a cytoplasmic 17beta-hydroxysteroid dehydrogenase of human secretory endometrium were studied. Using oestradiol as substrate, oestrone formation was found to be linear with time and the concentration of protein. The optimum temperature was 40 degrees C and the optimum pH 9.5. For the reduction of oestrone the optimal pH was 6. With NADP the maximal velocity was about 1/3 of that with NAD (0.23 nmoles/mg protein/10 min). The Km for oestradiol was 3.3 times 10- minus 6 M. Testosterone and androstenedione also served as substrates but they were interconverted more slowly than oestradiol and oestrone. Sulphhydryl groups were shown to be essential for catalysis. The enzyme is cold sensitive but cold inactivation can be reduced by NAD, NADP, oestradiol or glycerol.


The role of reduced glutathione in thyroglobulin proteolysis iv vitro. During the process of secretion of the thyroid hormones, stored thyroglobulin (Tg) is digested within the lysosomes. An acid protease has been found, but this enzyme hydrolyses Tg at a relatively slow rate and has a low pH optimum (3.6). Since previous work has shown a stimulatory effect of reduced glutathione (GSH) on Tg digestion the following studies have been performed. Homogenates were obtained from dog thyroid and total homogenate or different subcellular fractions were used as enzyme source. Labelled thyroglobulin (125-I) was purufied from prelabelled dog thyroid and its hydrolysis, judged from the increase in butanol soluble radioactivity, was studied. The greatest stimulatory effect of GSH on Tg hydrolysis was found around pH 5.6. When butanol soluble radioactivity was considered as a function of incubation time and tissue concentration a linear relationship was found. GSH effect was evident at 2 mM. Subcellular distribution studies showed that the GSH-stimulated proteolytic activity was mainly found in the 15 000 times g pellet. Labelled Tg hydrolysis was progressively decreased with increasing amounts of non-labelled purified Tg. GSH also stimulated labelled insulin hydrolysis, but failed to alter haemoglobin or casein degradation. GSH could also be replaced by other reducing agents, like cysteine or dithiothreitol. The significance of these findings is discussed in relation to the process of thyroid hormone secretion.


Additional data on hepatic function tests in cystic fibrosis. Fifty cystic fibrosis (CF) patients, of whom 9 had multilobular cirrhosis, were observed regularly for a period of 3 years and various liver function tests, indicating cytolysis, cholestasis and cellular insufficiency were performed. Immunoglobulin and prothrombin were assayed. In 9 patients with cirrhosis, the tests were generally abnormal. Two distinct biochemical patterns of cirrhosis were distinguished, one clearly cholestatic and the other of a more cellular type. The distinction was made on the basis of the IgA : Transferrin ratio and of gamma-glutamyl-transpeptidase levels. In the non-cirrhotic patients, a temporary increase of cytolysis and cholestasis was observed in 50% of the cases.


Production of cell-bound antigens by Bacteroides fragilis nctc 9343 in continuous culture. Highly active antigen preparations, as measured by precipitation and inhibition of haemaglutination, were obtained from Bacteroides fragilis NCTC 9343 grown in continuous culture. The activity varied slightly only with the glucose concentration of the medium and the dilution rate. pH had a greater influence on antigen production.


The effect of low-calcium diet and vitamin-D-3 on acid-base balance in young rabbits. The effect of low-calcium diet and vitamin D-3 on acid-base balance in young rabbits. Acta Physiol. Pol. 1975, 26 (1): 103-108. The effect of secondary hyperparathyroidism and vitamin D-3 on the acid-base balance was investigated in young rabbits. No metabolic acidosis was found in animals given vitamin D-3 in addition to low-calcium diet.


Adenylate cyclase activation in lymphoid tissues during graft-versus-host reaction. Graft-versus-host reactions were induced in adult F1 hybrid animals by injecting parental spleen cells. Adenylate cyclase activity was determined in the washed cell particles of the lymphoid tissues. During a time course study of the regional GVH reaction an increase in lymph node weight was apparent at day 2, whereas the adenylate cyclase activity increased at day 4 after the injection. Maximal lymph node hypertrophy and adenylate cyclase activation were observed 8 to 10 days after initiation of the GVH response. Adenylate cyclase stimulation by epinephrine of the GVH response. Adenylate cyclase stimulation by epinephrine and glucagon in experimental preparations was less than in the control. NaF was stimulatory only in the control preparations. Ca-2+ in concentrations up to 8 mM had no inhibitory effects on the control or experimental preparations. The pattern of responses of the experimental preparations to Zn-2+ and Cu-2+ was different than the control; however, in high concentrations both of these cations had marked inhibitory effects. An increase in the adenylate cyclase activity was also direct relationship between the adenylate cyclase activity and the cytolytic activity of spleen cells from mice undergoing systemic GVH reaction. These results can be explained on the basis of alterations in the cell membranes, and it is suggested that such changes play an important role in the pathogenesis of GVH disease.


Headaches in children.

Headaches in children. "Common" nonspecific headaches are the most frequent headaches in childhood and do not require a visit to the physician. Migraine is the most common of the headache syndromes with characteristic profiles, followed by the muscle contraction (tension), inflammatory and psychogenic types. Less frequent are mass or brain tumor headaches, malformation and hypertensive headaches. Migraine goes unrecognized more than the other common syndromes. Minor tranquilization may stop the pattern. The most important aspect of treatment for muscle contraction headache is recognition.


Nutritional stability of various naturally occurring monoglutamate derivatives of folic acid. The nutritional stabilities of four major dietary folates were studied as their corresponding monoglutamates and were compared to pteroylglutamate (folic acid) itself. The study of the monoglutamyl rather than polyglutamyl forms was justified since the former are formed during the course of digestion and also addition of extra glutamyl residues is unlikely to affect the types of nutritional instability associated with these derivatives. Since ability to support growth in Lactobacillus casei is known to reflect nutritional activity in man this organism was used in the stability studies. It was found that pteroylglutamate and 5-formyltetrahydropteroylglutamate had nutritional stabilities of the order of weeks although the stability of the former was decreased by phosphate. Surprisingly 10-formyltetrahydropteroylglutamate was nutritionally more stable than expected, possibly due to its conversion to the more stable oxidized 10-formylpteroylglutamate or to the reduced 5-formyl derivative. In contrast 5-methyltetrahydropteroylglutamate was much less stable nutritionally than expected.Unsubstituted tetrahydropteroylglutamate was most unstable nutritionally but in contrast to the other derivatives examined it was more stable under acidic than basic conditions. Ascorbate was found to be a far superior stabilizing agent than 2-mercaptoethanol at comparable concentrations.


Pepsin output after disruption of the human gastric mucosal barrier by taurocholic acid. Test solutions containing 10 mM taurocholic acid in 160 mM HCl were instilled into the stomachs of healthy volunteers to disrupt the gastric mucosal barrier. Although significant back diffusion of hydrogen ions and exsorption of sodium ions occurred, there was no significant increase in pepsin output compared to control studies with 160 mm HCl alone. Our data suggest that 160 mM HCl produces a many-fold increase in basal pepsin output. In the innervated stomach of man disruption of the gastric mucosal barrier by taurocholic acid in acid solution is not accompanied by increased pepsin secretion compared to that produced by 160 mM HCl alone.


Comparative study of secretin and Lundh tests. Exocrine pancreatic function in 19 patients with pancreatic disease and in 14 of 16 controls was measured by secretin stimulation and by the Lundh test on two different occasions. Peak bicarbonate concentration in the Lundh test emerged as the most reliable parameters. No additional diagnostic value was obtained by measuring enzymes after secretin injection. In 6 patients with chronic and in 8 of 13 patients with acute pancreatitis, both tests gave results that agreed with each other. The remaining 5 patients showed either an abnormal secretin value or an abnormal Lundh test. This is consistent with the wide variation seen in acute pancreatitis. It is concluded that the Lundh test as well as the secretin test were of value in the assessment of chronic pancreatic disease. The secretin test may be slightly more sensitive to mild and acute pancreatic damage than is the Lundh test. However stimulation of the pancreas by a test meal is easier to perform and more economic.


Pharmacology and clinical use of antacids. The pharmacology of antacids, with particular reference to their clinical use in treating acid-peptic disease, is discussed.  Liquid antacid suspension should be given at least as often as one hour after each meal and at bedtime.  Inthe treatment of the acute phase of acid-peptic disease, hourly antacid is recommended.  The dose should be planned in terms of milliequivalents of acid neutralizing capacity and should be adjusted according to the type of disease under treatment.  All antacids have side effects, the most serious of which are metabolic.  In clinical terms, the harmful sustemicside effects of calcium carbonate and sodium bicarbonate outweigh their benefit as neutralizing agents; they should rarely be employed in the treatment of acid-peptic disease.  The more common antacid side effects of diarrhea (magnesium hydroxide) and constipation (aluminum hydroxide) are best managed by appropriately alternating the agents or by using one of the various antacid mixtures.


Arterial blood gases and pH during sleep in chronic obstructive pulmonary disease. Arterial blood gases were measured during 7 hours of sleep in 15 patients with severe stable chronic obstructive pulmonary discrease (COPD); 6 awake patients with COPD studies in recumbency for an average of 5 hours served as controls. Mean maximal decrease in arterial oxygen partial pressure (PaO2) (plus or minus SD) was 13.5 plus or minus 3.9 mm Hg for sleeping patients (p less than 0.005) and 5.5 plus or minus 1.7 mm Hg for controls (p less than 0.1), respectively. Changes in pH during sleep were of the magnitude expected with acute changes in arterial carbon dioxide partial pressure (PaCO2) in patients with chronic hypercapnia. Consistent changes in heart rate, respiratory frequency or cardiac rhythm were not observed during sleep. Nocturnal worsening of hypoxemia could be explained by alveolar hypoventilation in six sleeping patients and in five controls; in nine sleeping patients, further impariment of ventilation-perfusion mismatch also contributed to worsening of hypoxemia. There was no relationship between the decrease in PaO2 during sleep and the degree of airways obstruction or the PaO2 level when awake. Because of low PaO2, when awake, a fall in PaO2 during sleep brings values into the steep part of the oxyhemoglobin dissociation curve where slight changes in PaO2 result in marked changes in oxygen content. All patients with COPD whose waking PaO2 was below 60 mm Hg had PaO2 below 50 mm Hg during sleep; nocturnal oxygen therapy should be considered in such patients, particularly in the presence of polycythemia or troublesome right-sided heart failure.


Perinatal infection and vaginal flora.

Perinatal infection and vaginal flora. Vaginal cultures were obtained from 1, 083 mothers on admission to the labor floor. The additional bacteriologic information gained from this survey was not sufficient to warrant continued use of the admission vaginal culture as a screening procedure.


Surface properties of the amniotic fluid in normal pregnancy. The surface properties of the amniotic fluid were determined in 96 normal pregnancies between weeks 23 and 41. The y-max, y-min, hysteresis areaa, and stability index were used as parameters for evaluation of the surface tension are diagrams. These results were plotted against the gestation week and a curve for the normal course of surface tension of the amniotic fluid during the second half of gestation was obtained. The influence of addition of blood, vernix, and meconium to amniotic fluid as well as that of changes in the pH and dilution were examined. The results were unaffected by either blood, vernix, or pH changes. The slight scatter of the y-min values makes this parameter particularly suitable for determining fetal lung maturity.


Placenta to lamb fetus transfusion in utero during acute hypoxia. Maternal and fetal hemodynamics, placental blood flow, fetal-placental blood volume, placental blood volume, and fetal blood volumes were measured in six chronic sheep prepartions to evaluate their changes during acute fetal hypoxia induced by maternal hypoxia. During fetal hypoxia, the maternal and fetal arterial blood pressure and heart rate were essentially unchanged. The placental blood flow (control equal to 325 ml.per kilogram per minute) was also unchanged during the hypoxia period. However, the placental blood volume decreased significantly from 65 to 60 and 51 ml. per kilogram at 15 and 30 minutes of hypoxia period, respectively. The fetal blood volume increased reciprocally and significantly from 86 to 109 and 102 ml. per kilogram at the same periods of hypoxia since the fetal-placental blood volumes were unchanged. These blood volume changes persisted for 30 to 60 minutes following the stoppage of hypoxia experiments. The placental vascular resistance measured in six experiments showed a significant increment during hypoxia, suggesting placental vasoconstriction as the responsible mechanism for the reduction of placental blood volume and reciprocal increase in fetal blood volume. The data suggest that significant placental transfusion to the lamb fetus may occur in utero during fetal hypoxia resulting in a higher fetal blood volume before birth.


Non-contact tonometry by assistants.

Non-contact tonometry by assistants. The ability of assistants to screen for elevated intraocular pressure (IOP) with the non-contact tonometer was evaluated. They had ten minutes of instruction with the instrument prior to the study. The estimates by the assistants correlated highly with those of the optometrists. The patients' responses were favorable. It follows from this study that an assistant with minimal training can reliably perform IOP screening with the non-contact tonometer under the supervision of an optometrist.


Tissue culture of bone marrow. V. Effect of 5Beta(H) steroids and cyclic AMP on heme synthesis. In mice 5beta(H) steroids have been shown tostimulate heme synthesis in vivo. The current studies were undertaken to evaluate the effect of these steroids on heme synthesis by use of the "well" method of marrow culture. The 5beta(H) steroid metabolites 3alpha-hydroxy-5beta-pregnane-11, 20-dione, 3beta-hydroxy-5beta-pregnan-20-one, 3 alpha,17alpha-dihydroxy-5beta-androstan-3-one stimulated Fe uptake by human marrow explants cultured in wells. The dibutyrl analog of adenosine 3',5'-monophosphate (db cAMP) also stimulated Fe uptake. The effect of the latter compound was enhanced by theophylline. There was no additive nor synergistic effect between db cAMP and the 5beta(H) steroid metabolites. There was no inhibition of the steroid metabolite effect by either antierythropoietin serum or cyproterone. Uptake of fe was also enhanced by the cations Ca++ and Co++.


Hydrocortisone restoration of the pH-dependent metabolic responses to catecholamines. Feeding NH4CL to fasted rats caused changes of blood levels of lactate, glycerol, and insulin, hepatic levels of glycogen and phosphorylase, and muscle levels of glycogen and glucose 6-P in the direction opposite to the changes induced by respiratory alkalosis. The effects of epinephrine and isoproterenol in vivo on these metabolic indices, which are classified as their function mediated via the adrenegic beta receptor, were potentiated by NH4CL feeding in contrast to their attenuation in alkalosis. The prior treatment of the rat with hydrocortisone was very effective in overcoming the alkalosis-induced inhibition of the beta-receptor-mediated metabolic actions of epinephrine and isoproterenol, such as the activation of liver phosphorylase, accumulation of muscle hexose phosphates, and stimulation of pancreatic secretion of insulin. Epinephrine sensitivity of the liver and muscle levels of cyclic AMP was not altered by the hydrocortisone therapy or inductions of alkalosis and acidosis. The mechanism for the hydrocortisone restoration of the adrenergic beta functions in alkalosis is discussed as related to its permissive effect.


Inotropic and intracellular acid-base changes during metabolic acidosis. Experiments in isolated, Ringer-perfused isovolumic rabbit hearts showed that metabolic acidosis resulted in a decrease in peak left ventricular pressure and dP/dt. Concomitantly, the decrease in extracellular pH from 7.28 plus or minus 0.02 to 6.82 plus or minus 0.02 at constant PaCO2 was associated with a negative av HCO3- difference that lasted throughout the duration of acidosis. This negative av HCO3- difference indicated that either HCO3- moved into the intravascular space or H+ moved in the opposite direction during acidosis. During perfusion with normal pH solution av HCO3- was not significantly different from zero. Washout of the extracellular space with the acid solution can account for only 32 percent of the total amount of HCO3-recovered in the venous perfusate during the 30 min of acidosis. The remaining 68 percent (10.7 plus or minus 3.1 mmol times kg-1 of cardiac tissue) must then have originated in the cellular fluid. When intracellular fluid volume is taken into account, it can be calculated that 21.3 plus or minus 6.1 mmol of HCO3- moved into the vascular space per liter of intracellular water. The magnitude of this HCO3- flux suggests that significant myocardial cellular acid-base changes are associated with metabolic acidosis.


Ileal HCO3 secretion: relationship to Na and Cl transport and effect of theophylline. Interrelationships among Na, Cl, and HCO3 transport processes were examined in short-circuited rabbit ileal mucosa. As serosal (HCO3) was increased from 10 to 50 mM (pH from 7.1 to 7.8), net Na absorption decreased from 4.6 to 0.3 mueq/h-cm2, net Cl flux changed from absorption of 0.9 to secretion of 0.9 and a net HCO3 secretion of 3.0 developed. A similar change in net Cl flux was also observed when serosal Pco2 was altered at constant (HCO3). In Cl-free SO4-Ringer, serosal alkalinization produced net HCO3 secretion which was not significantly less than that observed in Cl-containing Ringer. Theophylline caused secretory changes in net Na and Cl fluxes at both 10 and 50 mM serosal (HCO3). Theophylline did not alter net HCO3 flux in Cl-Ringer but increased net HCO3 flux in SO4-Ringer. Total dc conductance was decreased by both serosal alkalinization and theophylline. Shortcircuit current was consistently increased by theophylline but not by serosal alkalinization. The results indicate that ileal ion transport is regulated in part by serosal pH and/or (HCO3) and that resulting changes in Cl and HCO3 transport are coupled one-for-one with changes in Na transport. Furthermore, HCO3 secretion does not require the presence of Cl in the bathing medium.


Tetany: quantitative interrelationships between calcium and alkalosis. Tetany occurs with hypocalcemia and alkalosis or both. The interrelationship of calcium and acid-base balance necessary for inducing tetany, the role of the central nervous system, and the rate of development of hypocalcemia have been investigated. Tetany occurred in less than 50 percent of one group of dogs made alkalotic by hyperventilation or made hypocalcemic by infusion of ethylene glycol-bis(beta-amino ethyl ether) N, N'-tetraacetate. In contrast, hypocalcemia combined with hypocapnic alkalosis always produced tetany. Slowly evolving hypocalcemia was achieved inanother group of dogs by thyroparathyroidectomy, and tetany was induced postoperatively by hypocapnic alkalosis. An identical relationship between serum calcium ion concentration and arterial pH or CO2 tension was found in both groups. Tetany could not be related to the cerebrospinal fluid (CSF) calcium ion content in either group. Hypocalcemia and alkalosis are therefore coparticipants in the development of tetany and are independent of the rate of development of hypocalcemia and of CSF calcium ion concentration. The importance of alkalosis in tetany with hypoparathyroidism is emphasized.


Distribution of H+ and HCO3 minus between CSF and blood during metabolic acidosis in dogs. To determine whether the regulation of brain extracellular fluid acid-base balance is by active ion transport or passive distribution, changes in cisternal and lumbar cerebrospinal fluid (CSF) (H+) and (HCO3 minus) were assessed in five dogs with normal acid-base status and in six dogs during metabolic acidosis. Both groups were mechanically ventilated to maintain a constant PaCO2. The pH, PCO2, (HCO3 minus), and (lactate) in CSF and arterial plasma and the CSF/plasma DC potential difference were determined at intervals, and the electrochemical potential differnces (mu) for H+ and HCO3 minus were calculated. Following control measurements at pHa equal to 7.40, metabolic acidosis was induced by infusion of 0.6 N HCl. Measurements were made 0, 3, 4.5, and 6 h thereafter and at 0, 3, and 6 h in the control series. A steady state for ion distribution was reached by 4.5 h. In the control series at 6 h the values of mu for H+ and HCO3 minus were within minus 0.2 and +0.5 mV of initial values at the cistern and +0.1 and +0.9 mV at the lumbar site. During metabolic acidosis, the 6-h values at the cistern returned to 0.0 and +0.7 mV of control for muH+ and muHCO3 minus while lumbar values returned to +0.5 and minus 0.4 mV. The closeness of these 6-h values of mu to control is compatible with passive distribution of H+ and HCO3 minus between CSF and blood.


Distribution of H+ and HCO3 minus between CSF and blood during respiratory acidosis in dogs. To evaluate the regulation of (H+) and (HCO3 minus) in brain extracellular fluid during respiratory acidosis, the changes in cisternal and lumbar CSF acid-base state were assessed in six anteshetized, paralyzed, mechanically ventilated dogs rendered hypercapnic by increase in FIco2. Arterial (HCO3 minus) was held constant. The electrochemical potential difference (mu) between CSF and blood for H+ and HCO3 minus was calculated from values for (H+) and (HCO3 minus) in CSF and arterial plasma and the simultaneously measured CSF/plasma DC potential difference. Measurements were made at pHa equal to 7.40, after stable arterial values of pHa of about 7.2 were attained and 3, 4.5, and 6 h thereafter. A steady state for ion distribution was attained by 4.5 h. Values of mu for H+ and HCO3 minus at 6 h had returned to +0.7 and minus 0.7 mV of control for cisternal CSF and +1.3 and minus 0.6 mV of control for lumbar CSF. The attainment of steady-state values for mu close to control is comparable with passive distribution of these ions between CSF and blood.


Distribution of H+ and HCO3 minus between CSF and blood during respiratory alkalosis in dogs. Anesthetized, paralyzed dogs after a control period at normal pHa were hyperventilated to produce a hypocapnic alkalosis. The pH, PCO2, (HCO3 minus), and (lactate) in cisternal and lumbar CSF and arterial blood were determined at normal conditions (control) shortly after induction of respiratory alkalosis (time 0) and 3, 4.5, and 6 h thereafter. These values along with measurements of the CSF/plasma DC potential (E) allowed calculations of the electrochemical potential difference (mu) between CSF and blood for H+ and HCO3 minus. After 6 h of hypocapnic alkalosis, muH+ and muHCO3 minus had returned to minus 0.7 and minus 1.0 mV of control at the cistern and to minus 1.0 and +0.4 mV of control for lumbar CSF. This return of mu is compatible with a passive distribution of these ions though active ion regulation is not ruled out. Assuming passive distribution, differences in deltaE/DELTApHa between metabolic and respiratory acid-base changes determined the extent of CSF pH homeostasis during compensated acid-base derangements.


Ion transport across the excised bullfrog lung. Fluxes of ions and water across the short-circuited, excised bullfrog lung were determined by radioisotope techniques. The unidirectional flows of Na+, K+, Ca++, TcO4 minus, HCO3 minus, gluconate, rho-aminohippurate, dinitrophenolate, SO4 equal to, and water were symmetrical. Both HCO3 minus fluxes were reduced by acetazolamide. In contrast, Cl minus, Br minus I minus, and SCN minus movement from serosa to mucosa exceeded the flux in the opposite direction. Net Cl minus transport followed the kinetics of a saturable process and was inhibited by dinitrophenol and hypoxia. These results indicate an active secretion of halide anions and SCN minus into the lumen. Attempts to demonstrate Br minus anatagonism of Cl minus transport were equivocal. Cl minus transport accounted for 50 percent minus of the early short-circuit current but after 90 min the two measurements were equal. Incubation of the lung in bicarbonate-free Ringer revealed unequal decreases in the H+ concentration of the bathing solutions. Net "base" addition to the serosal solution was reduced by prior removal of the blood from the pulmonary vasculature. Therefore, "base" release could not be localized to the epithelia. The Na+, K+, Ca++ and Cl minus composition of the lung tissue was unchanged over 3 h. Since tissue and, hence cell Cl minus is lower than the concentration in the bathing solution the Cl pump is probably located in the luminal border of the alveolar epithelial cell.


Effects of physical training on cardiac myosin ATPase activity. Cardiac myosin from rats exercised 90 or 150 min daily for 8 wk was compared with the myosin from the hearts of matched sedentary controls. The Ca++-ATPase activity was increased 17 percent in rats exercised 90 min and 30 percent in rats exercised 150 min daily. In the exercised group 0.18 M KCl increased the myosin ATPase activity by 50 percent but had no effect in the control group. Ethylene glycol activated the Ca++-ATPase in control myosin preparations, but had no significant effect on myosin from conditioned hearts. Heavy meromyosin (HMM) from conditioned hearts had a higher Ca++-ATPase activity than from controls. Fluorescence with 8-anilinonaphthalene sulfonate (ANS) was increased 30 percent in HMM from conditioned hearts. The results suggest that the increased myosin ATPase activity in the hearts of exercised animals may be due to a local conformational change at or near the active site.


Ion transport by amphibian antrum in vitro. I. General characteristics. Both Necturus and bullfrog antrum show stable PD, resistance, and short-circuit current (Isc) when mounted in an Ussing chamber. Measurements of Na+ and Cl minus flux showed that both ions are actively transported across Necturus antrum, Na+ from secretory to nutrient, Cl minus from nutrient to secretory (both net fluxes being similar to 0.30 mueq cm minus 2 h minus 1). Only the Na+ transport contributed to the Isc and PD as evidenced by a) Na+ removal, b) the effects of amiloride on the secretory surface, c) the effects of ouabain on the nutrient side. Microelectrode experiments confirm the Na+ conductance of the secretory cell membrance, a HCO3 minus conductance of both cell membranes, and a KCl conductance across the nutrient cell membrane. In addition, antrum apparently secretes alkali (similar to 0.35 mueq cm minus 2 h minus 1), which secretion is sensitive to metabolic inhibitors and Diamox. Nutrientside HCO3 minus increased the rate of alkaline secretion and a transmucosal HCO3 minus gradient could contribute to ISC and PD. A model is proposed to account for the electrical properties of the tissue.


Pulmonary effects of paraquat in the first day after injection. To learn whether surface force changes precede the appearance of lung edema during experimental intoxication due to paraquat, we studied rats for 1 day following injection of 27 mg/kg iv. By 24 h, surface-active material recovered by lung lavage was decreased 32 percent, and changes in lung microsections and recoil pressure at half-deflation suggested decreased alveolar stability. Despite a 25 percent loss in overall body weight, lung weight increased more than 7 percent and protein concentration in lung lavage fluid increased by 158 percent. Lung edema was demonstrated morphologically as early as we could detect changes in surfactant or lung mechanical properties. Metabolic studies with lung tissue slices incubated with 4.5 times 10-4 M paraquat showed a fourfold increase in 14CO2 formed from (1-14C) glucose, but no significant change in 14CO2 form (6-14C) glucose, suggesting increased utilization of the pentose pathway for oxidation of glucose. (1-14C) Acetate oxidation was impaired slightly, but incorporation into lipid was decreased by 70 percent. we conclude that paraquat intoxication in the rat is not a suitable model for studying uncomplicated perturbation of the surfactant system.


Calcium and angiotensin tachyphylaxis in rat uterine smooth muscle. Studies were carried out to investigate the relationship between extracellular Ca++ and the ability of a particular smooth muscle to develop tachyphylaxis to angiotensin II (AII). Stimulation of rat uterus by AII was found to be dependent on extracellular Ca++. Placing the tissue in 0 Ca++ completely blocked AII-induced contractions as did the presence of the "Ca++ antagonists" verapamil (10- minus 5M), SKF 525-A (10- MINUS 5M), tetracaine (10- minus 4M), Mn++ (8 times 10- minus 3M), or La-3+ (10- minus 3M). In addition, it is no longer possible to produce tachyphylaxis to AII in deplorazed rat uterus under conditions of pH and Ca++ concentration in which a normally polarized preparation would be unresponsive. Verapamil, on the other hand, was an even more effective antagonist of AII in depolarized preparations (ID50 of 10- minus 8M) than in normal tissues (ID50 of 2.0 times 10- minus 7M). Like the rat uterus, the smooth muscle of the guinea pig ileum also develops tachyphylaxis to AII, and the effect of this peptide was also blocked by 10- minus 5 M verapamil. Rabbit aorta, however, was found to be relatively resistant to both development of tachyphylaxis under conditions of low Ca++ and low pH and also to inhibition by even very high concentrations of verapamil (10- minus 4M). The results of these studies suggest that the Ca++ site involved in the tachyphylactic response to AII may be a physiologically important one in those smooth muscles in which movement of extracellular Ca++ contributes to the inward ion currents during excitation. Verapamil, however, appears to act at a common step in the excitation-contraction sequence in rat uterus. A working model of the interaction of AII with rat uterine smooth muscle is presented.


Uteroplacental blood flow during alkalosis in the sheep. Uteroplacental blood flow was measured by the radioactive-microsphere technique in eight near-term pregnant ewes during a normal control period and during maternal metabolic alkalosis. All measurements were made on awake, unanesthetized animals. Alkalosis, defined for this study as an arterial pH of 7.60 or greater, was produced by the oral administration of sodium bicarbonate, 3 g/kg body wt. The rise in pH thus produced was unaccompanied by significant changes in systemic arterial blood pressure and cardiac output, while maternal arterial Pco2 rose slightly from control levels. Cotyledonary blood flow declined from a control value of 1,177 ml/min to 1,025 ml/min during alkalosis. This decline of 13 percent in cotyledonary blood flow is significant (P smaller than 0.002). Blood flow to the remaining uterine tissue, or noncotyledonary uterus, did not change with alkalosis, being maintained at approximately 195 ml/min. It is concluded that maternal alkalosis, unaccompained by major changes in Pco2 and systemic arterial pressure, causes a small increase in the resistance of the uteroplacental circulation.


Bicarbonate and sodium reabsorption by the isolated perfused kidney. The role of bicarbonate reabsorption and of transtubular chloride gradients in the bulk reabsorption of sodium and water by renal tubules can be tested in the isolated perfused kidney by perfusing with a medium from which bicarbonate has been omitted. Perfusion of the isolated rat kidney with an artificial medium in which bicarbonate is replaced by chloride results in a fall in fractional reabsorption of sodium from 97 to 84%. Stepwise restoration of bicarbonate concentration in the perfusion medium to 25 meq/liter is associated with a parallel recovery of sodium reabsorption to control levels. Inhibition of bicarbonate reabsorption with acetazolamide produces a slightly smaller reduction in sodium reabsorption (97-89%), an effect not seen in the absence of bicarbonate. Acetazolamide greatly increases phosphate excretion and free water clearance in a way consistent with suppression of proximal tubular reabsorption. By contrast, simple omission of bicarbonate from the perfusing medium does not alter phosphaturia or free water clearance. Reabsorption of bicarbonate appears to account for a fraction of sodium reabsorption roughly equivalent to the proportion of sodium associated stoichiometrically with bicarbonate in the glomerule filtrate. The data do not support the hypothesis that the development of a transtubular chloride gradient is critically important for the reabsorption of a large fraction of the glomerular filtrate.


Effects of acid-base changes, hypoxia, and catecholamines on ventricular performance. Extracellular pH changes were produced in dogs with tris (hydroxy-methyl)-aminomethane (Tris) or NaHCO3 in the presence or absence of hypoxemia and before and after beta-adrenergic blockade with propranolol. Ventricular performance (VP) was evaluated by measurement of maximum rate of rise of left ventricular pressure (dp/dt max) and left ventricular end-diastolic pressure in the canine right heart bypass preparation with aortic pressure, heart rate, and cardiac output held constant. Low pH diminished VP. Hypoxemia did not alter VP within the pH, suggesting that decreased V observed with acidosis before propranolol was due primarily to decreased myocardial response to catecholamines. Increase of pH with Tris increased VP significantly more than with NaHCO3. Beta blockade diminished the response of VP to Tris at a high pH;prior administration of reserpine abolished the inotropic effect of Tris. The data suggest that Tris can influence VP independent of its effect on pH. This effect is probably mediated by the interaction between endogenous catecholamines and myocardial beta receptors.


Effect of temperature on rate of CO2 uptake by human red cell suspensions. The time course of carbon dioxide uptake by oxygenated supensions of human red cells was followed using a CO2 electrode in a Hartridge-Roughton continuous-flow rapid-reaction apparatus. Measurements were made at several temperatures from 1i to 42 degrees C, with the initial PCO2 in the reacting mixture from 40 to 60 mmHg. The initial part of the uptake curve is presumably rate limited by the intracellular hydration of CO2 with reaction-velocity constants in cell water from 280 to 960 S-1 at 42 degrees C and an activation energy of 2.4 kcal mol-1. The later stages of CO2 uptake were much slower, with half-times from greater than 1.5 s at 12 degrees C to 0.7 s at 42 degrees C, and were presumably rate limited by the chloride-bicarbonate shift and H+ interchanges. The results indicate that despite the acceleration of the hydration reaction in cell water by a factor of 5,000 at 37 degrees C and 3,800 at 42 degrees C, the later part of the exchange is too slow to permit blood to come intoC02, equilibrium with actively exercising muscles during its passage through the capillary bed.


Effect of vagal innervation on the secretory responses of canine gastric pouches exposed to bile. The changes in the secretory response to a meat meal, after preliminary exposure of vagally innervated and vagally denervated fundic pouches to ox bile at pH 7 and pH 2, have been defined. In the innervated pouches, exposure to bile at both pH levels caused transient inhibition of gastric acid secretion. In both types of pouch, the output of Na+ in the gastric juice was presistently increased due to enhanced exchange diffusion. The changes were more pronounced after exposure to bile at pH 2 than after exposure to bile at pH 7. After exposure to bile, exchange diffusion was more increased in the innervated pouches than in the denervated. The results suggested that the innervated mucosa was more susceptible than was the denervated mucosa to the injurious effects of bile.