The role of interferon in the protective effect of a synthetic double-stranded polyribonucleotide against intranasal vesicular stomatitis virus challenge in mice

• Text
• PDF

Abstract

Authors

Hemodynamics, coronary blood flow, and myocardial metabolism in coronary shock; response to l-norepinephrine and isoproterenol

• Text
• PDF

Abstract

Authors

Imbalances of gamma globulin subgroups and gene defects in patients with primary hypogammaglobulinemia

• Text
• PDF

Abstract

Analysis of immunoglobulin classes, γG subgroups, and Gm genetic markers from 59 patients with various types of immune deficiencies was undertaken to assess the function of the several cistrons concerned with synthesis of gamma globulins. 13 patients including two sibling pairs were found to have γG subgroup imbalances. All of these patients had non sex-linked disease. 11 of the 13 had preponderance of the γG3 subgroup. In most instances of γG3 preponderance it was the Gm(b) type of γG3 that was selectively retained; the Gm(g) type, controlled by the allelic gene was markedly depressed but not absent in the cases where it could be studied. Other imbalances, either seen concomitantly with γG3 preponderance or independently, included predominance of the γG2 subgroup and selective absence of single γG subgroups.

Authors

W. J. Yount, R. Hong, M. Seligmann, R. Good, H. G. Kunkel

Relation of renal cortical gluconeogenesis, glutamate content, and production of ammonia

• Text
• PDF

Abstract

Glutamate is an inhibitor of phosphate dependent glutaminase (PDG), and renal cortical glutamate is decreased in metabolic acidosis. It has been postulated previously that the rise in renal production of ammonia from glutamine in metabolic acidosis is due primarily to activation of cortical PDG as a consequence of the fall in glutamate. The decrease in cortical glutamate has been attributed to the increase in the capacity of cortex to convert glutamate to glucose in acidosis.

Authors

Anthony S. Pagliara, A. David Goodman

Studies in vivo and in vitro on an abnormality in the metabolism of C3 in a patient with increased susceptibility to infection

• Text
• PDF

Abstract

In a patient with increased susceptibility to infection, lowered serum C3 concentration, and continuously circulating C3b, it was shown that purified 125I-labeled C3 was converted to labeled C3b shortly after intravenous administration. The fractional catabolic rate of C3 was approximately five times normal at 10% of the plasma pool per hr. The synthesis rate and pool distribution of C3 were normal. Despite this evidence of C3 instability in vivo, no accelerated inactivation of C3 was found in vitro. Similarly, no free proteolytic activity could be detected in the patient's serum, and serum concentrations of known protease inhibitors were normal.

Authors

Chester A. Alper, Neil Abramson, Richard B. Johnston Jr., James H. Jandl, Fred S. Rosen

Erythropoiesis in the anemia of bone marrow failure

• Text
• PDF

Abstract

The quantitative relationship between red cell volume, erythropoietin level, and erythropoiesis was evaluated in 43 human beings. Results in normal man were compared with studies in patients with anemia from bone marrow failure and with polycythemia vera. The maximum erythropoietin excretion after bleeding normal men was similar to the basal levels found in patients with chronic anemia of similar magnitude. Although erythropoietin values were low in patients with polycythemia vera, bleeding evoked a normal response. In patients anemic from bone marrow failure, basal levels were elevated, and phlebotomy resulted in an increase consistent with the new level of anemia. These observations indicate that erythropoietin level is affected primarily by the degree of anemia and is not influenced by the duration of anemia. In normal subjects, a fivefold increase in urinary erythropoietin was associated with a doubling of erythropoiesis. Despite similar degrees of erythropoietin production, anemic patients with evidence of bone marrow in the lower extremities had greater red cell production. In patients with polycythemia vera, red cell production was inappropriately elevated with regard to the urinary erythropoietin excretion. Bone marrow maturation time was not shortened in patients anemic from bone marrow failure to the same degree as in bled, normal volunteers. In addition to an adequate level of erythropoietin production, normal bone marrow function is necessary for maximal shortening of maturation time.

Authors

Raymond Alexanian, Clarence Alfrey

Mechanism of action of thyroid hormones on erythrocyte 2,3-diphosphoglyceric acid synthesis

• Text
• PDF

Abstract

Normal erythrocytes, when incubated with thyroid hormone, were found to have increased levels of 2,3-diphosphoglyceric acid. In addition, a partially purified enzyme preparation, when incubated with either a 1,3-diphosphoglyceric acid generating system or 1,3-diphosphoglyceric acid directly, showed increased levels of 2,3-diphosphoglyceric acid when exposed to thyroid hormone. The hormonal effect was biphasic and was witnessed after 5 min of incubation. Substitution on the 3 and 5 positions of the basic thyronine molecule was essential for hormonal effect. It appears that thyroid hormone acts by directly stimulating the diphosphoglycerate mutase enzyme. The hormonal effect on 2,3-DPG synthesis may offer a biochemical explanation for the shift in the oxyhemoglobin dissociation curve observed in thyroid disorders.

Authors

L. Michael Snyder, William J. Reddy

Blood levels and production rate of 17-hydroxypregnenolone in man

• Text
• PDF

Abstract

A reliable radio-ligand assay has been developed for the measurement of 17-hydroxypregnenolone in human peripheral vein plasma. The mean plasma concentration of 17-hydroxypregnenolone was, in men, 1.9 mμg/ml; and in women, 3.5 mμg/ml. These means were not significantly different from each other, and the levels were the same in the follicular and luteal phases of the menstrual cycle. In women, the adrenal cortex was the source of the 17-hydroxypregnenolone; in men, 40% was produced by the testis. Since the metabolic clearance rate was about 2000 liters/24 hr production rate estimates were 4-7 mg/24 hr.

Authors

C. A. Strott, J. A. Bermudez, M. B. Lipsett

The role of hemoglobin heme loss in Heinz body formation: studies with a partially heme-deficient hemoglobin and with genetically unstable hemoglobins

• Text
• PDF

Abstract

A number of mutant hemoglobins are inordinately unstable, denaturing in circulating red cells into Heinz bodies, resulting in congenital Heinz body hemolytic anemia (CHBHA). We have emphasized that most such hemoglobins involve amino acid substitutions at sites neighboring the heme group of the β-polypeptide chain, and have shown that heme binding to globin is diminished thereby. Thus, hemes were progressively lost from four unstable hemoglobins (Köln, Hammersmith, San Francisco, and Zürich) as they precipitated into Heinz bodies at 50°C.

Authors

Harry S. Jacob, Kaspar H. Winterhalter

Splanchnic metabolism of free fatty acids and production of triglycerides of very low density lipoproteins in normotriglyceridemic and hypertriglyceridemic humans

• Text
• PDF

Abstract

Transport of free fatty acids from the blood into the splanchnic region and their conversion to triglycerides of very low density lipoproteins, together with estimates of splanchnic oxidation of free fatty acids to ketones and to carbon dioxide and water, have been made in the postabsorptive state in seven normolipemic subjects, six with primary endogenous hyperlipemia and one each with primary dysbetalipoproteinemia and mixed hyperlipemia. Net systemic transport of free fatty acids into the blood was the same in normolipemic and hyperlipemic groups, but a greater fraction was taken up in the splanchnic region in the latter. Transport into the blood in very low density lipoproteins of triglyceride fatty acids derived from free fatty acids was proportional and bore the same relationship to splanchnic uptake of free fatty acids in the two groups. In normolipemic subjects, near equilibration of specific activities after 4 hr infusion of palmitate-1-14C showed that almost all triglyceride fatty acids of very low density lipoproteins and acetoacetate were derived from free fatty acids taken up in the splanchnic region. In the hyperlipemic subjects, equilibration of free fatty acidcarbon with acetoacetate was almost complete, but not with triglyceride fatty acids, owing at least in part to increased pool size. Comparison of the rate of equilibration of triglyceride fatty acids-14C with rate of inflow transport from the splanchnic region, together with other data, indicated that most of the circulating triglyceride fatty acids of very low density lipoproteins in hyperlipemic subjects were also derived from free fatty acids. Although mean inflow transport of triglyceride fatty acids was greater in the hyperlipemic subjects, it correlated poorly with their concentration and it appeared that efficiency of mechanisms for extrahepatic removal must be a major determinant of the concentration of triglycerides in blood plasma of the normolipemic as well as the hyperlipemic subjects. Estimates of splanchnic respiratory quotient supported the concept that oxidation of free fatty acids accounts for almost all of splanchnic oxygen consumption in the postabsorptive state. Splanchnic oxygen consumption was greater in the hyperlipemics, but fractional oxidation of free fatty acids to ketones was higher in normolipemic subjects. Calculations of splanchnic balance indicate that a larger fraction of free fatty acids was stored in lipids of splanchnic tissues in the hyperlipemics. No differences were found between the two groups in net splanchnic transport of glucose, lactate, or glycerol.

Authors

R. J. Havel, J. P. Kane, E. O. Balasse, N. Segel, L. V. Basso

Hemodynamic effects of phenoxybenzamine in anesthetized dogs

• Text
• PDF

Abstract

Our studies demonstrated that phenoxybenzamine, 10 mg/kg, administered intravenously to intact anesthetized dogs, produced an immediate and significant increase of heart rate and cardiac output. In heart-lung preparations, phenoxybenzamine had no effect or a negative cardiac inotropic effect, hence these actions were not related to direct cardiac action or to release of myocardial norepinephrine stores. Serial estimations of arterial blood catecholamines after phenoxybenzamine showed an increase of epinephrine and norepinephrine; the peak values of these catecholamines did not correlate well with the maximum cardiac output responses. Ganglionic blockade largely eliminated the early cardiac effects of phenoxybenzamine, hence its action did not appear to be upon peripheral terminals of postganglionic sympathetic or parasympathetic nerves. Phenoxybenzamine was found to have antivagal actions which might account for some of the delayed cardiac acceleration. When beta adrenergic receptor blockade was induced by sotalol, the cardiac effects of phenoxybenzamine were largely eliminated. Baroreceptor denervation prevented the increase of cardiac output after phenoxybenzamine. These observations are consistent with the concept that the increase of cardiac rate and output produced by phenoxybenzamine is principally mediated by baroreceptor reflexes acting through sympathetic cardiac nerves or circulating catecholamines.

Authors

Noble O. Fowler, John C. Holmes, Thomas E. Gaffney, Philip J. Privitera, Gunter Grupp

Nucleoside deaminase: an enzymatic marker for stress erythropoiesis in the mouse

• Text
• PDF

Abstract

The level of nucleoside deaminase was determined in extracts of mouse tissues obtained during a period of accelerated erythropoiesis induced by hypoxia, hemorrhage, or the injection of phenylhydrazine. Under these conditions a striking (10- to 100-fold) elevation of the enzyme activity occurred in the spleen. Similar results were obtained with the injection of purified erythropoietin. In control animals, only a trace of nucleoside deaminase activity was detected in the blood. During the reticulocyte response which followed erythropoietic stimulation, there was a sharp increase in the blood level of nucleoside deaminase, which rose up to 120 times that of control animals. By differential centrifugation, the enzyme was localized to the reticulocyte-rich fraction. Erythrocyte nucleoside deaminase remained elevated even after the reticulocyte count had fallen to normal in the phenylhydrazine-treated mice or to zero after the cessation of hypoxia. There was a very gradual decline in the enzyme activity in the blood which fell to the barely detectable control levels about 45 days after the initial reticulocyte response, a time period which corresponds to the survival of the mouse red blood cell. The persistence of high levels of nucleoside deaminase for the full life span of a generation of erythrocytes formed during stress, viewed in contrast to the virtual absence of the enzyme from normal erythrocytes of all ages, represents an enzymatic difference between the normal red blood cell and the cell produced under conditions of accelerated erythropoiesis.

Authors

Ivan K. Rothman, Esmail D. Zanjani, Albert S. Gordon, Robert Silber

Qualitative description of factors involved in the retraction and lysis of dilute whole blood clots and in the aggregation and retraction of platelets

• Text
• PDF

Abstract

Dilute whole blood clots were prepared by addition of thrombin to blood diluted 1:10 in phosphate buffer. The pH of this buffer was 7.4 and the ionic strength was 0.084. Though the ionic strength was low, there was no hemolysis of red corpuscles due to the contribution to the osmotic gradient by plasma salts and proteins. In the standard assay the clot was formed by addition of thrombin at 4°C then incubated at 37°C. Retraction and lysis of these clots were inhibited by removal of platelets and by increasing concentrations of purified thrombin. Retraction and lysis were also inhibited by inactivation of any one of the following factors: γM globulin, complement components C4 and 3, and (in the case of lysis) plasminogen.

Authors

Fletcher B. Taylor Jr., Hans J. Müller-Eberhard

Human alveolar macrophages: comparison of phagocytic ability, glucose utilization, and ultrastructure in smokers and nonsmokers

• Text
• PDF

Abstract

Phagocytic ability, glucose utilization, and ultrastructural morphology were studied in human alveolar macrophages in smokers and nonsmokers. The macrophages were obtained by bronchopulmonary lavage and the studies were carried out in vitro in the absence of smoke. Phagocytic ability was measured as the decrease in the number of viable Staphylococcus albus organisms incubated with the macrophages. Measurements of 14CO2 formation from glucose-U-14C were made in a resting state. 90-95% of the cells obtained by lavage were large mononuclear macrophages of which approximately 90% remained viable at the end of the experiment. Smokers yielded many more macrophages per lavage (mean 46.4 × 106 ±7.4) compared to the nonsmokers (mean 10.2 × 106 ±2.3). The decline in viable organisms was the same in each group, indicating phagocytic competence of alveolar macrophages removed from smokers. However, the mean glucose utilization for the smokers was 4.3 ±0.2 mμmoles/106 cells and 1.4 ±0.7 mμmoles/106 cells for the nonsmokers. This very significant difference (P < 0.0001) suggests that smokers' macrophages have a higher resting energy requirement than those of nonsmokers. Comparison of the ultrastructural morphology of the alveolar macrophages from each group reveals that the cells from smokers differ from those of nonsmokers in that they are slightly larger, and contain more golgi vesicles, endoplasmic reticulum, and residual bodies. The residual bodies in smokers' cells contain distinctive fiber-like inclusions.

Authors

James O. Harris, Edward W. Swenson, Joseph E. Johnson III

Perifusion of rat pancreatic tissue in vitro: substrate modification of theophylline-induced biphasic insulin release

• Text
• PDF

Abstract

The immunoreactive insulin (IRI) release patterns produced by continuous theophylline stimulation of rat pancreas have been defined, using an in vitro perfusion system. In the presence of glucose, citrate, and pyruvate at concentrations which were nonstimulatory by themselves, continuous stimulation with theophylline produced a biphasic IRI release profile. In the absence of substrate, continuous theophylline stimulation produced only an abrupt and limited primary response. Of the substrates tested, only glucose significantly enhanced this primary response. With increasing theophylline concentrations, whether in the presence or absence of substrate, significant increases were noted in the primary response as estimated by either the maximum rate of IRI release attained or by the total amount of IRI released during this time. Similarly, the secondary responses to theophylline increased with theophylline concentration in the presence of either citrate or pyruvate. With glucose as substrate, however, increasing theophylline concentrations from 2.5 to 5, then 10 mM produced a progressive reduction in both indices of the secondary response, which was inversely related to the primary response. These findings suggest that cyclic AMP not only mediates IRI release in quantitative terms but is also implicated in the qualitative nature of the response pattern. They also indicate a possible metabolic basis for biphasic IRI release, the acute or primary response being dependent upon the basal state of the cell and the availability of endogenous energy sources, the secondary response upon the availability of exogenous substrate.

Authors

Ian M. Burr, Luc Balant, Werner Stauffacher, Albert E. Renold

Localization of fluorescein-labeled antinucleoside antibodies in glomeruli of patients with active systemic lupus erythematosus nephritis

• Text
• PDF

Abstract

Renal tissues from two groups of patients were studied with fluorescein-labeled (Fl-) antibodies (Abs) to immunoglobulins, complement, and antibodies prepared in rabbits against BSA conjugate of 5-methyluridine (T) and cytidine (C), the latter two of which react specifically with denatured DNA. The first group consisted of 13 SLE patients, and the second consisted of 53 patients with non-SLE nephropathies. The data obtained from the two groups of patients were used for comparison, and they showed the following:

Authors

G. A. Andres, L. Accinni, S. M. Beiser, C. L. Christian, G. A. Cinotti, B. F. Erlanger, K. C. Hsu, B. C. Seegal

Potassium balance and the control of renin secretion

• Text
• PDF

Abstract

Plasma renin activity and renin substrate were measured in nine groups of rats which were maintained for 7 wk on diets in which the proportions of sodium and potassium were varied.

Authors

Jean E. Sealey, Irwin Clark, Marcia B. Bull, John H. Laragh

The influence of potassium administration and of potassium deprivation on plasma renin in normal and hypertensive subjects

• Text
• PDF

Abstract

The effect of potassium administration and of dietary potassium deprivation on plasma renin activity and aldosterone excretion has been studied in 10 normal subjects and in 12 hypertensive patients maintained on a constant dietary regimen.

Authors

Hans R. Brunner, Leslie Baer, Jean E. Sealey, John G. G. Ledingham, John H. Laragh

Reduced brain glucose with normal plasma glucose in salicylate poisoning

• Text
• PDF

Abstract

After the intraperitoneal injection into young mice of 700-800 mg/kg of salicylate, brain glucose fell to one-third or less of control values despite normal plasma glucose levels; brain lactate was nearly doubled and there were small decreases in phosphocreatine (18%) and in glycogen (17%). ATP, pyruvate, α-ketoglutarate, and glutamate were unchanged. In liver, glycogen was reduced 79% and lactate was five times higher than in control animals; glucose, glucose-6-phosphate, and ATP were unchanged.

Authors

Jean Holowach Thurston, Philip G. Pollock, Sheila K. Warren, Elizabeth M. Jones

The role of phosphate in the secretion of parathyroid hormone in man

• Text
• PDF

Abstract

In man, oral administration of 1 g of phosphorus resulted in a 60-125% increase in serum immunoassayable parathyroid hormone (PTH) concentration. Peak PTH levels were attained in 1 hr, and PTH returned to base line levels in 2 hr. This increase in PTH appeared to be initiated by a very small decrease of total and ionized calcium and was abolished by a calcium infusion. There was no correlation between serum phosphorus and PTH. The experiments show that oral phosphorus administration initiates a calcium-mediated control system for PTH secretion and that this system operates very sensitively in man.

Authors

Eric Reiss, Janet M. Canterbury, Margaret A. Bercovitz, Edwin L. Kaplan