Renal Distribution Volumes of Indocyanine Green, [⁵¹Cr]EDTA, and ²⁴Na in Man during Acute Renal Failure after Shock. IMPLICATIONS FOR THE PATHOGENESIS OF ANURIA

• Text
• PDF

Abstract

The mechanism responsible for the anuria in acute renal failure after shock is still controversial. Suppressed glomerular filtration and/or tubular back-diffusion of the filtrate are major possible causes. In the present investigation, seven patients with acute anuria, three of these seven again in the polyuric phase, six patients with moderate renal impairment, four patients with chronic renal failure, and eight subjects with normal renal function were studied by a multiple indicator-dilution method in which the total renal blood flow and renal distribution volumes of indocyanine green, [51Cr]EDTA, and 24Na were determined. In normal subjects the average values for one kidney were 582 ml/min, 42 ml, 92 ml, and 139 ml, respectively. The measurements in the patients with moderate renal impairment were similar to those in the normal subjects, but were decreased in chronic renal failure. In acute anuria, the average values were 269 ml/min, 40 ml, 101 ml, and 114 ml and the kidney volume, estimated radiographically, was increased by 40%. When expressed as milliliters per milliliters kidney, the average distribution volume of 24Na was decreased from 0.64 to 0.38. This decrease is consistent with the hypothesis that suppressed filtration is largely responsible for the anuria and that back-diffusion is, at most, a contributory factor. The apparent contradiction between the relatively well-preserved total blood flow and the suppressed filtration may be due to a combination of afferent vasoconstriction and efferent vasodilatation. This view is supported by the observation that low filtration fractions were found in clearance measurements performed during the polyuric phase.

Authors

F. C. Reubi, C. Vorburger, J. Tuckman

The Interaction of Serum and Arterial Lipoproteins with Elastin of the Arterial Intima and Its Role in the Lipid Accumulation in Atherosclerotic Plaques

• Text
• PDF

Abstract

Arterial elastin appears to be a proteinlipid complex with the lipid component being bound to elastin peptide groups. In atherosclerotic lesions the lipid content of elastin increases progressively with increasing severity of atherosclerosis. The increases in the lipid content of plaque elastin are mainly due to large increases in cholesterol with about 80% of the cholesterol being cholesterol ester. This deposition of cholesterol in elastin accounts for a substantial part of the total cholesterol accumulation in atherosclerotic lesions of all stages. The present in vitro study suggests that the mechanism involved in the deposition of lipids in arterial elastin may be an interaction of the elastin protein with serum or arterial low density or very low density lipoproteins (LDL and VLDL) resulting in a transfer of lipids, but not of lipoprotein protein to the elastin. No significant lipid transfer occurred from the high density lipoproteins or chylomicrons. The amount of lipid taken up by plaque elastin was strikingly higher than by normal elastin and consisted mainly of cholesterol with over 80% of the cholesterol being cholesterol ester. The precondition for the lipid accumulation in plaque elastin appeared to be an altered amino acid composition of the elastin protein consisting of an increase in polar amino acids and a reduction in cross-linking amino acids. Subsequent treatment of lipoprotein-incubated arterial elastin with hot alkali and apolipoproteins did not reverse the binding of lipoprotein lipid to diseased elastin.

Authors

Dieter M. Kramsch, William Hollander

The Effect of Experimental Diabetes Mellitus and Insulin Replacement on Hepatic Ultrastructure and Protein Synthesis

• Text
• PDF

Abstract

The following study was conducted in order to define the specific alterations in hepatic ultrastructure responsible for the decrease in hepatic protein synthesis associated with experimental diabetes. Rats received intravenous alloxan (70 mg/kg) and 48 h later were either sacrificed or given insulin for 1, 2, 4, 6, or 24 h. Specimens for electron microscopic evaluation and morphometric analysis were taken from the same livers used to isolate ribosomes for measurement of in vitro protein synthesis. Our results show that hepatocytes from animals with untreated alloxan diabetes show varying degrees of disorganization and loss of rough endoplasmic reticulum (RER) which is directly related to the severity of the alloxan diabetes. A significant correlation existed between the severity of ultrastructural changes as judged by the loss of both membrane and polysome components of the RER and degree of inhibition of protein synthesis (P < 0.001). Abnormalities of hepatic ultrastructure and protein synthesis were reversed within 24 h of insulin administration. The data are consistent with the view that it is the relative decrease in hepatic polysomes that results from the loss of RER in alloxan diabetes that is responsible for the decrease in hepatic protein synthesis.

Authors

Eve P. Reaven, Daniel T. Peterson, Gerald M. Reaven

Proximal and Distal Tubular Function in Salt-Deprived and in Salt-Loaded Deoxycorticosterone Acetate-Escaped Rats

• Text
• PDF

Abstract

Proximal and distal tubular function was compared with urinary excretion in rats after chronic administration of salt and deoxycorticosterone acetate (DOCA) or during salt deprivation. DOCA rats excreted significantly more sodium than did salt-deprived rats. Measurements of tubular fluid to plasma (TF/P) inulin ratios and concentrations of sodium and potassium in quantitative, timed collections, related to measured tubular length, allowed calculation of absolute reabsorption of fluid and ions in the different nephron segments. Proximal transport was not reduced in DOCA-treated rats compared with salt-deprived animals; in distal tubule the former group reabsorbed more sodium and secreted less potassium than the latter. Calculation of sodium transport in loop of Henle as the difference in flow between the end of the proximal convolution and the beginnings of the distal tubule indicated no inhibition of reabsorption in DOCA animals. Comparison of end-distal tubular flow with simultaneous urinary excretion suggested that sodium load was not the determining factor of enhanced natriuresis in DOCA-treated animals. The data are interpreted as indicating that DOCA-escape in the rat is associated with specific alteration of sodium transport in the collecting duct system.

Authors

H. Sonnenberg

Immunobiology of Fibrinogen. EMERGENCE OF NEOANTIGENIC EXPRESSIONS DURING PHYSIOLOGIC CLEAVAGE IN VITRO AND IN VIVO

• Text
• PDF

Abstract

Physiological degradation of fibrinogen by plasmin leads to a recognized series of intermediate and stable terminal cleavage fragments and is associated with complex modulation and progressive loss of native antigenic expressions. Early in association with progressive plasmin cleavage, a stable cleavage-associated neoantigen, present in the D-fragment region of the molecule, is exposed in vitro and can be recognized by competitive inhibition radioimmunoassay with specific antiserum. It is demonstrated that there is an approximate equimolar expression of the cleavage-associated neoantigen. fg-Dneo, on the X-, Y-, and D-fragments and no recognizable (< 10-3) expression by fibrinogen or by the E-fragment. The X-fragment contains two D regions in respect to total D-fragment-associated antigenic expressions but unitary expression of fg-Dneo is observed. The Y-fragment appears to contain one D-fragment region in respect to total D-fragment-associated antigens and exhibits close to unitary expression of fg-Dneo. Terminal cleavage digests containing the D- and E-fragments exhibit more than 10-fold greater native fibrinogen antigenic expression than the sum of the constituent fragments. This suggests the presence of a non-covalently associated native complex of the D- and E-fragments, and implies contiguity of the D- and E-fragments in the native fibrinogen molecule. The cleavage-associated neoantigen, fg-Dneo, is also generated in vivo and is generically demonstrable in the plasma of patients with various forms of in vivo fibrinolysis.

Authors

Edward Plow, Thomas S. Edgington

Studies of T- and B-Lymphocytes in Patients with Connective Tissue Diseases

• Text
• PDF

Abstract

Peripheral blood lymphocytes from normal subjects as well as patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and active tuberculosis were studied for the relative distribution of bone marrow-derived lymphocytes (B-cells) and thymic-derived T-cells. B-cells were identified by direct immunofluorescence of surface Ig markers; T-cells were studied using rabbit antisera to pooled human fetal thymocytes absorbed with chronic lymphatic leukemia lymphocytes as a source of B-cells. In normal subjects, the sum of percentages of peripheral blood lymphocytes staining for surface Ig (B-cells) plus the percentage of cells staining with the absorbed antithymocyte antiserum closely approximated 100%. The mean value for percent B-cells among 51 normals tested was 22.9%±7.1; mean T-cells value was 75.3±13.95%. T-cell-specific antiserum stained 18% of normal human bone marrow lymphocytes, 42.5% of lymphocytes from normal spleens, and 98% of cells obtained from thoracic duct drainage of patients with RA. Specificity of antihuman thymocyte antiserum appeared to depend on the use of living cells.

Authors

Ralph C. Williams Jr., James R. DeBoard, Ove J. Mellbye, Ronald P. Messner, Folke D. Lindström

Pathogenesis of Postprandial Hyperlipemia in Rats Fed Ethanol-Containing Diets

• Text
• PDF

Abstract

To study the mechanism of the increase in serum lipoproteins which occurs in rats fed alcohol chronically, and especially to assess the role of the intestine, the effects of acute and chronic ethanol administration on lymph and plasma lipids were compared in rats with and without intestinal lymph fistulae. In rats not previously given alcohol, the administration of one dose of a diet containing ethanol (3 g/kg) produced a significant increase in lymph flow, lipid output, and incorporation of dietary fat into lymph lipids when compared with the effects of a control diet containing isocaloric carbohydrate. However, no hyperlipemia developed after ethanol. By contrast, previous feeding of ethanol for several weeks modified the acute effects of ethanol on both lymph and serum lipids. Compared with control animals pair-fed with isocaloric carbohydrate-containing diets, rats which had been fed a diet with 36% of total calories as ethanol for 3-4 wk developed postprandial hyperlipemia when given a single dose of the ethanol-containing or even the ethanol-free diet. This was associated with an increased incorporation of labeled dietary fat and of intravenously injected [3H]lysine into plasma lipoproteins of d < 1.006. However, postprandial lymph flow and lipid output were not higher in rats fed alcohol chronically than in their pair-fed controls. Moreover, when rats with lymph fistulae were given intravenous (i.v.) infusions of lymph lipids (to substitute for the diverted intestinal lymph), the ethanol-fed animals still developed hyperlipemia. Incorporation of i.v. lysine into d < 1.006 plasma lipoproteins also remained significantly increased. Thus, under these conditions, alcoholic hyperlipemia does not result from changes in intestinal lymph lipids. Two main factors appear to be involved; the acute effects of ethanol on hepatic lipid metabolism and the development of an increased capacity for lipoprotein synthesis during chronic ethanol feeding. The latter most likely occurs in the liver and it is postulated that it is linked to the associated changes in the hepatic endoplasmic reticulum.

Authors

E. Baraona, R. C. Pirola, C. S. Lieber

Direct Measurement of Osteolysis in Man

• Text
• PDF

Abstract

Precise, direct measurement of bone calcium release (vo-) has been accomplished using a continuous tracer administration (CTA) technique. Dietary calcium (96.97% 40Ca) is replaced by 40Ca (99.991% 40Ca) and blood levels of the naturally occuring isotope 48Ca are monitored by neutron activation analysis as a function of time. 48Ca abundance falls as this isotope is excreted and only partially replaced by release from bone. After a suitable period, an asymptotic abundance of 48Ca in serum, E, is approached which is the fraction of the turnover rate of the rapidly exchangeable calcium pools coming from the skeleton (E = vo-/vt). E is determined with a standard error of 2%, providing a precise, sensitive index of vo-. 13 studies in three normal men and one postmenopausal woman receiving maintenance estrogen show large intersubject variations in parameters of calcium metabolism using both CTA and pulse tracer administration (PTA) plus balance techniques. Induced hypercalcemia results in a prolonged decrease in vo-. Glucocorticoid therapy initially and consistently induces a marked hypercalciuria while effects on most other parameters of calcium kinetics are variable. In two men E fell when testosterone was added to glucocorticoid treatment, consistent with the known antiosteolytic effect of androgens, despite the short period of study.

Authors

James W. Hansen, Gilbert S. Gordan, Stanley G. Prussin

Relationship between Deoxyribonucleoprotein and Deoxyribonucleic Acid Antibodies in Systemic Lupus Erythematosus

• Text
• PDF

Abstract

A soluble preparation of nucleoprotein (sNP), a complex of native deoxyribonucleic acid (DNA) and histones, was isolated from calf thymus nuclei and labeled with [125I]iodide. Isotope-labeled antigen ([125I]sNP) was used in a primary binding radioimmunoassay method to detect antibodies to both sNP and native DNA. Sera with antibody to native DNA reacted with the DNA moiety of sNP and bound [125I] sNP, but this binding was completely inhibited by addition of unlabeled native DNA. Antibody to sNP which reacted with DNA-histone complex was not inhibited in the radioimmunoassay by addition of unlabeled DNA. Thus, antibodies to sNP and native DNA could be detected and differentiated by use of a single isotopically labeled antigen. In systemic lupus erythematosus (SLE), sera with binding to [125I]sNP was present in 21/36 (58%) patients. The majority (18/21) had antibodies to sNP and native DNA present simultaneously, one had antibody only to sNP and two had antibody only to DNA. In contrast, patients with other connective tissue diseases rarely showed binding to [125I]sNP. Serial studies on SLE patients showed that high serum binding to [125I]sNP paralleled renal disease activity as reflected by the degree of proteinuria. A fall in binding was observed with subsidence of renal disease and reappearance of increased binding coincided with exacerbation. In these patients, antibodies to sNP and DNA appeared or disappeared pari passu suggesting that in addition to the previously demonstrated role of antibody to native DNA, antibody to sNP might also be implicated in the pathogenesis of immunologically-mediated tissue lesions such as SLE nephritis.

Authors

Pierre Robitaille, Eng M. Tan

Studies on Red Cell Aplasia. V. PRESENCE OF ERYTHROBLAST CYTOTOXICITY IN γG-GLOBULIN FRACTION OF PLASMA

• Text
• PDF

Abstract

The marrow cells of a patient with pure red cell aplasia markedly increased their rate of heme synthesis when they were freed from the host environment and were incubated in vitro. When the red cell aplasia was treated with cyclophosphamide and prednisone, marrow cell incorporation of 59Fe into heme in vitro increased several weeks before a reticulocytosis was apparent, and was the earliest effect noted. The plasma γG-globulins of this patient inhibited heme synthesis by normal marrow cells or the patient's own marrow cells obtained after remission of the disease.

Authors

Sanford B. Krantz, W. H. Moore, S. Donald Zaentz

Mechanism of the Lower Esophageal Sphincter Relaxation ACTION OF PROSTAGLANDIN E₁ AND THEOPHYLLINE

• Text
• PDF

Abstract

The intravenous injection of prostaglandin E1 (PGE1) causes a dose-dependent relaxation of the lower esophageal sphincter (LES) in the intact, lightly anesthetized opossum. The action of PGE1 is not inhibited by the drugs that produce muscarinic or nicotinic cholinergic antagonism or alpha and beta adrenergic antagonism in the doses that inhibited the action of respective agonists. Moreover, this action is not affected by exogenous gastrin pentapeptide. The action of PGE1 on the LES is mimicked by isoproterenol, theophylline ethylenediamine, and dibutyryl cyclic AMP. Both theophylline, a phosphodiesterase inhibitor, and isoproterenol, an adenyl cyclase stimulator, added to the action of PGE1. On the other hand, adenyl cyclase inhibitor nicotinic acid, as well as phosphodiesterase stimulator, imidazole inhibited its action. Further, both nicotinic acid and imidazole inhibited the degree of LES relaxation produced by esophageal distension. These studies suggest that intracellular cyclic AMP may act as the “second messenger” in the regulation of the lower esophageal sphincter relaxation.

Authors

Raj K. Goyal, Satish Rattan

Hemoglobin Olympia (β20 Valine → Methionine): An Electrophoretically Silent Variant Associated with High Oxygen Affinity and Erythrocytosis

• Text
• PDF

Abstract

In a family with erythrocytosis, electrophoretic and chromatographic studies failed to demonstrate a hemoglobin variant. However, the oxygen dissociation curves of affected individuals were shifted to the left of normal and this shift persisted when oxygen equilibria were studied in 2.3-diphosphoglycerate-stripped hemolysates. A mutant hemoglobin was evidently present in the red blood cells of the affected persons and was responsible for the increased oxygen affinity and erythrocytosis. Specific staining of tryptic peptide maps of β-chains from the propositus showed that peptide βT3 was positive for a sulfur-containing amino acid. Amino acid analysis yielded a composition identical to that of normal βT3, except that there were 2.6 residues of valine and 0.4 residues of methionine (normal composition: Val = 3.0, Met = 0). This suggested that the β-chains of affected individuals consisted of a mixture of two kinds of chains, 40% of which had a methionyl residue in βT3. Structural studies of isolated cyanogen bromide fragments demonstrated unequivocally that, in the abnormal β-chains, valine in position 20 is replaced by methionine. The new hemoglobin mutant is designated hemoglobin Olympia (β20 (B2) valine → methionine).

Authors

George Stamatoyannopoulos, Peter E. Nute, John W. Adamson, A. J. Bellingham, Donald Funk

Rheology of Leukocytes, Leukocyte Suspensions, and Blood in Leukemia POSSIBLE RELATIONSHIP TO CLINICAL MANIFESTATIONS

• Text
• PDF

Abstract

Suspensions of leukemic lymphocytes and myeloblasts and blood of leukemic patients were studied to examine (a) the effect of leukemic cells on blood viscosity and (b) the ability of leukemic cells to traverse channels of capillary diameter. The viscosity of suspensions of leukemic cells was dependent logarithmically on (a) shear strain rate and (b) cytocrit, although, suspensions of small lymphocytes and of myeloblasts had a similar viscosity at equivalent shear rates and cytocrit. The minimum apparent viscosity (MAV) of leukemic cells and red blood cells, measured over shear rates of 2.3-230 s-1 was dependent logarithmically on cytocrit. However, MAV was slightly greater for leukemic cells than for red cells at cytocrits up to 20%. At cytocrits above 20%. MAV of leukemic cells increased more rapidly than that of erythrocytes. For example, at a 15% cytocrit MAVWBC (1.85 centipoise) was only slightly greater than MAVRBC (1.59); whereas, at 45% cytocrit MAVWBC (14.9) was markedly greater than MAVRBC (3.81).

Authors

Marshall A. Lichtman

Vertical Distributions of Pulmonary Diffusing Capacity and Capillary Blood Flow in Man

• Text
• PDF

Abstract

In six normal upright subjects, a 100 mol bolus—composed of equal parts of neon, carbon monoxide, and acetylene (Ne, CO, and C2H2)—was inspired from either residual volume (RV) or functional residual capacity (FRC) during a slow inspiration from RV to total lung capacity (TLC). After breath holding and subsequent collection of the exhalate, diffusing capacity and pulmonary capillary blood flow per liter of lung volume (DL/VA and Q̇C/VA) were calculated from the rates of CO and C2H2 disappearances relative to Ne. The means: DL/VA = 5.26 ml/min × mm Hg per liter (bolus at RV), 6.54 ml/min × mm Hg per liter (at FRC); Q̇C/VA 0.537 liters/minute per liter (bolus at RV), 0.992 liters/minute per liter (at FRC). Similar maneuvers using Xenon-133 confirmed that, during inspiration, more of the bolus goes to the upper zone if introduced at RV and more to the lower, if at FRC. A lung model has been constructed which describes how DL/VA and Q̇C/VA must be distributed to satisfy the experimental data. According to this model, there is a steep gradient of Q̇C/VA, increasing from apex to base, similar to that previously determined by other techniques—and also a gradient in the same direction, although not as steep, for DL/VA. This more uniform distribution of DL/VA compared with Q̇C/VA indicates a vertical unevenness of diffusing capacity with respect to blood flow (DL/Q̇C). However, the relative degree of vertical unevenness of DL/VA compared with Q̇C/VA can account only in part for previous observations attributed to the inhomogeneity of DL/VA and Q̇C/VA. Thus, a more generalized unevennes of these ratios must exist throughout the lung, independent of gravitation.

Authors

Edward D. Michaelson, Marvin A. Sackner, Robert L. Johnson Jr.

Interactions of the Classical and Alternate Complement Pathway with Endotoxin Lipopolysaccharide EFFECT ON PLATELETS AND BLOOD COAGULATION

• Text
• PDF

Abstract

The contributions of the classical and alternate pathways of complement activation to the biological effects of endotoxin have been examined in the guinea pig, with particular reference to thrombocytopenia, leukopenia, and the development of the hypercoagulable state. Injection of endotoxin into normal guinea pigs led to a 95% fall in the level of circulating platelets within 15 min as well as a fall in circulating granulocytes. C4-deficient guinea pigs, known to have a complete block in the activity of the classical complement pathway, but with the alternate pathway intact, sustained no fall in platelets. The development of granulocytopenia proceeded normally. Endotoxin did activate the alternate complement pathway in C4D guinea pigs, as evidenced by the fall in C3-9 titers. With restoration of serum C4 levels, endotoxin-induced thrombocytopenia was observed in C4D animals. Thus, function of the classical complement pathway was an absolute requirement for the development of thrombocytopenia. Experiments performed in cobra venom factor (CVF)-treated normal guinea pigs, with normal levels of C1, C4, and C2, but with less than 1% of serum C3-9 demonstrated the importance of the late components in the development of thrombocytopenia but not leukopenia.

Authors

Michael A. Kane, Joseph E. May, Michael M. Frank

Combined Studies of Complement Receptor and Surface Immunoglobulin-Bearing Cells and Sheep Erythrocyte Rosette-Forming Cells in Normal and Leukemic Human Lymphocytes

• Text
• PDF

Abstract

Human lymphocytes from normal peripheral blood, thymus, spleen, thoracic duct, and peripheral lymphocytes from patients with chronic lymphatic leukemia were studied for complement receptor sites (CRL), surface immunoglobulin (SIg), and for the ability to form rosettes with sheep erythrocytes (TRFC). The two B cell markers (CRL and SIg) were found to be in overlapping, but not totally identical populations, whereas cells that were able to form rosettes were found in a totally unrelated population of lymphocytes; TRFC is therefore probably a reliable marker for T cells. In peripheral blood 24% of lymphocytes had SIg, but only half of these were also CRL. Almost all of the non-SIg peripheral blood lymphocytes were TRFC. In the spleen and thoracic duct only a few lymphocytes were observed that had SIg and were not CRL. On the other hand, in two of three spleens studied 10-20% of cells were CRL that did not have SIg. In the thoracic duct all non-CRL that did not have SIg. In the thoracic duct all non-CRL, non-SIg cells were TRFC. In chronic lymphatic leukemia three findings were made: (a) The presence or absence of CRL was independent of the presence or absence of SIg so that in individuals whose cells were non-SIg. CRL were usually plentiful. (b) Leukemic cells were essentially negative for TRFC. (c) Leukemic cells reacted poorly with human C3 compared to mouse C3, EACmo detecting up to 20-fold more CRL than EAChu. This latter finding was in sharp contrast to normal CRL that reacted somewhat preferentially with EAChu. These data suggest that altered surface Ig receptors and complement receptors are present in chronic lymphatic leukemic cells. Since the cells obtained from all leukemic patients tested in this study had either the complement receptor or surface immunoglobulin in a high percentage of their cells and were essentially negative for TRFC, it is strongly suggested that leukemic lymphocytes are of B cell origin. The finding of lymphocytes with only one of the two B cell markers suggests that these markers are not uniformly present on all B cells and that depending on the source, one or the other may be deficient.

Authors

Gordon D. Ross, Enrique M. Rabellino, Margaret J. Polley, Howard M. Grey

Micropuncture Studies of Sodium Tranport in the Remnant Kidney of the Dog THE EFFECT OF GRADED VOLUME EXPANSION

• Text
• PDF

Abstract

Proximal and distal tubule micropuncture studies were performed to examine the response to graded extracellular volume (ECV) expansion in 10 normal dogs (stage I), 11 dogs with a unilateral remnant kidney (stage II), and 7 dogs with a remnant kidney after removal of the contralateral kidney (stage III). Before ECV expansion in stage III, there was a suggestive reduction in proximal tubule as well as loop fractional reabsorption of sodium. After ECV expansion to 3% body weight proximal tubule reabsorption was depressed in all groups of animals, while little further inhibition was observed in this segment with additional expansion to 10% body weight. In contrast, the fraction of filtered sodium remaining in the distal tubule rose progressively in all three groups after graded ECV expansion, suggesting that the graded natriuretic response found in the final urine was largely due to a similar response in the loop of Henle rather than that in the proximal tubule. The distal tubule response of the remnant kidney in both stages II and III was greater than that in stage I. These data indicate that although enhanced sodium excretion per nephron in chronic renal failure may be related to uremia, its exaggerated response to ECV expansion is due, at least in part, to certain as yet unidentified intrarenal factors consequent to reduction in functioning renal mass.

Authors

Sung-Feng Wen, Norman L. M. Wong, Raphael L. Evanson, Earle A. Lockhart, John H. Dirks

Radioimmunoassay Measurement of Prostaglandins E, A, and F in Human Plasma

• Text
• PDF

Abstract

The details of a radioimmunoassay capable of measuring as 5 pg of prostaglandin A, E, and F (PGA, PGE, and PGF) in human and rat plasma are described. Plasma samples are extracted (with 4000 cpm [3H] PGE1 added for calculation of recovery) with an organic solvent system at an apparent pH of 5.8 and then chromatographed on silicic acid columns with increasing concentrations of methanol to separate PGA, PGE, and PGF. Each chromatographed sample is measured by radioimmunoassay, using the homologous antibody and tritiated marker. 40 normal individuals had mean plasma concentrations of PGA, PGE, and PGF of 1062±107 pg/ml, 385±30 pg/ml, and 141±15 pg/ml, respectively. Elevated PGE levels were measured in the plasma of patients with medullary carcinoma of the thyroid, carcinoid, and neuroblastoma. Treatment of rats with indomethacin decreased serum PGE levels by 67%. The radioimmunoassay appears to be of considerable experimental as well as clinical interest.

Authors

Bernard M. Jaffe, Harold R. Behrman, Charles W. Parker

Escherichia Coli Bacteremia in the Squirrel Monkey I. EFFECT OF COBRA VENOM FACTOR TREATMENT

• Text
• PDF

Abstract

Squirrel monkeys were significantly depleted of complement by a nontoxic protein constituent of cobra venom, and the influence of cobra factor (CoF) treatment on the course of Escherichia coli bacteremia was studied. Striking neutropenia occurred rapidly in control animals while the rate of occurrence of neutropenia was 20 to 30 times slower in the CoF-treated animals, suggesting that the E. coli-induced neutropenia was at least partially a complement-mediated response. In the CoF-treated monkeys, the initial rate of clearance of the E. coli from the circulation tended to be slower and the resultant levels of bacteremia were higher than in control animals. These observations are consistent with a hypothesis that complement-mediated neutrophilic leucocyte function is an important host defense mechanism in gram-ngeative bacillary bacteremia.

Authors

David N. Gilbert, Jack A. Barnett, Jay P. Sanford

Alterations in Distribution of Blood Flow to the Lung's Diffusion Surfaces During Exercise

• Text
• PDF

Abstract

We measured simultaneously, by single breath methods, pulmonary capillary blood flow (Q̇c), carbon monoxide diffusing capacity (DLCO), and isotopic oxygen (18O18O) diffusing capacity (DL18O2) in five normal males during conditions of rest and moderate exercise at mixed venous O2 tensions (PO2 33-44 mm Hg). During moderate exercise at a work load of 100 W. pulmonary capillary blood flow increased from 6.9±1.5 to 12.9±3.4 min-1 and DL18O2 increased from 25±4 to 43±3 ml·min-1·mm Hg-1, whereas DLCO showed no significant change (45±5 to 49±10 ml·min-1·mm Hg-1). DL18O2 increased proportionally to Q̇c (r = 0.74), where DLCO did not (r = 0.08). The greater increase in DL18O2 during exercise can be explained by a more homogeneous diffusion/perfusion (DLO2/Q̇c) distribution in the individual respiratory exchange units during exercise. This improved distribution of DLO2/Q̇c acts to help prevent an increase in alveolar-arterial O2 tension difference from developing despite the decrease in pulmonary erythrocyte transit times that occur during exercise. The insignificant rise in DLCO with exercise under these hypoxic breathholding conditions may result from pulmonary vasomotor responses to short-term hypoxia or from relative insensitivity of DLCO to moderate levels of exercise.

Authors

Carroll E. Cross, Henry Gong Jr., Cornelius J. Kurpershoek, Jerry R. Gillespie, Richard W. Hyde

Erythrocyte Hb-S Concentration AN IMPORTANT FACTOR IN THE LOW OXYGEN AFFINITY OF BLOOD IN SICKLE CELL ANEMIA

• Text
• PDF

Abstract

The blood in sickle cell anemia has a very low oxygen affinity and, although 2,3-diphosphoglycerate (2,3-DPG) is increased, there is doubt as to whether this is the only factor responsible. In this study of 15 patients with sickle cell anemia (Hb SS) no correlation was found between oxygen affinity (P50 at pH 7.13) and 2,3-DPG in fresh venous blood. Whole populations of Hb SS erythrocytes were therefore separated, by an ultracentrifuge technique, into fractions of varying density. The packed red cell column was divided into three fractions; a bottom fraction rich in deformed cells or irreversibly sickled cells (ISC), with a very high mean corpuscular hemoglobin concentration (MCHC); a middle fraction containing cells with the highest content of fetal hemoglobin; and a top fraction containing reticulocytes and discoid cells but free of deformed cells. Oxygen affinity was shifted to the right in all layers (mean P50 (pH 7.13)±1SD: top 46.3±2.9 mm Hg: middle 49.8±4.9 mm Hg; bottom 61.0±5.8 mm Hg) compared with normal blood (top 32.1±0.7 mm Hg: bottom 30.1±0.5 mm Hg). 2.3-DPG was increased in the top fraction, but was low or normal in the bottom fraction (top 21.8±3.4 μmol/g Hb: middle 17.7±2.2 μmol/g Hb; bottom 13.8±3.1 μmol/g Hb; normal whole blood 14.3±1.2 μmol/g Hb). The level of 2,3-DPG in top fractions could not account for the degree of right shift of P50, and in the middle and bottom fractions the even greater right shifts were associated with lower levels of 2,3-DPG. Top fraction cells depleted of 2,3-DPG had a higher, but still abnormally low, oxygen affinity. A strong relationship was found between oxygen affinity and MCHC. The fractions with the greatest right shift in P50 had the highest MCHC (top 32.4±2.0; middle 36.2±3.1; bottom 44.6±3.2 g/100 ml, respectively) and the plot of P50 vs. MCHC showed a positive correlation (r = 0.90, P < 0.001).

Authors

M. Seakins, W. N. Gibbs, P. F. Milner, J. F. Bertles

Metabolism of Steroid and Amino Acid Moieties of Conjugated Bile Acids in Man III. CHOLYLTAURINE (TAUROCHOLIC ACID)

• Text
• PDF

Abstract

After oral administration of [2,4-3H]-cholyl[35S]taurine to eight healthy subjects with indwelling nasoduodenal tubes, the specific activity of the cholyl and taurine moieties and the distribution of radioactivity in biliary bile acid and urinary metabolites, as well as total urinary and fecal 35S and 3H, were measured at intervals for 4-8 days. Similar measurements were made after [35S]taurine was given orally or intravenously or instilled into the distal intestine. The daily fractional turnover rate of the taurine moiety of cholyltaurine was low and similar to that of the cholyl moiety, indicating that deconjugation occurring during enterohepatic cycling was less than half that previously observed for glycine-conjugated bile acids. Some of the cholyl moiety was absorbed but, since reconjugation occurred predominantly with glycine, little reincorporation into the cholyltaurine pool was observed. Some of the taurine moiety was also absorbed intact but entered large taurine pools, and little reincorporation into the cholyltaurine pool was seen. Oral administration of taurine expanded the cholyltaurine pool and induced a decrease in the fractional turnover rate of the cholyl moiety of cholyltaurine, interpreted to indicate a greater reincorporation of the cholyl moiety because of increased reconjugation with taurine. Taurine moiety not absorbed as taurine appeared to be absorbed largely as sulfate which, like taurine, entered large endogenous pools. Little fecal excretion of 35S occurred. 35S was excreted in urine as taurine and sulfate, and excretion in the first 24 h (as percentage of administered dose) correlated highly (r = 0.93) with the daily fractional turnover rate of the taurine moiety. When taurine was instilled into the distal intestine, it appeared as such in plasma, but the more distal the site of instillation, the greater the fraction of urinary 35S present as sulfate. The [35S]sulfate appeared to have come from bacterial degradation of [35S]taurine because, when [35S]taurine was given intravenously, 35S was excreted in urine chiefly as [35S]taurine with little SO4=-[35S] being present.

Authors

Gershon W. Hepner, John A. Sturman, Alan F. Hofmann, Paul J. Thomas

Pathogenesis of Salmonellosis STUDIES OF FLUID SECRETION, MUCOSAL INVASION, AND MORPHOLOGIC REACTION IN THE RABBIT ILEUM

• Text
• PDF

Abstract

Strains of Salmonella typhimurium were studied in the ligated rabbit ileal loop model to gain insight into the mechanisms whereby bacteria which invade the gastrointestinal mucosa evoke fluid exsorption. The organisms employed differed in various biologic attributes including the ability to invade the ileal epithelium, multiply within the mucosa, elicit an acute inflammatory reaction, and disseminate across the intestinal wall. Some strains provoked small intestinal fluid exsorption although these did not elaborate enterotoxin. Only those strains which invaded the mucosa were accompanied by either mucosal inflammation or fluid exsorption. Noninvasive strains produced neither histologic abnormalities nor fluid secretion. While strains which invaded the mucosa caused an acute inflammatory reaction, not all such strains evoked fluid secretion. Furthermore, there was no correlation in ability of invasive organisms to evoke fluid secretion or in the intensity of mucosal inflammation, number of intramucosal salmonellae, or in ability to disseminate from the rabbit ileum.

Authors

R. A. Giannella, S. B. Formal, G. J. Dammin, H. Collins

Cellular Accumulation of L-Cystine in Rat Kidney Cortex In Vivo

• Text
• PDF

Abstract

Cellular accumulation of L-cystine in rat kidney cortex in vivo has been studied using L-[35S]cystine. The L-[35S]cystine radioactivity in plasma decreases to less than 10% of the initially calculated value by 15 min. Four 35S-containing intracellular products of L-cystine metabolism were identified including cystine, cysteine, reduced glutathione, and an as yet unidentified compound. The latter is probably taurine, cysteinesulphinate, or cysteic acid. Cellular accumulation of these products was found to be more rapid in vivo than in vitro. Cellular accumulation of the products of L-cystine metabolism was found to be essentially unchanged in the presence of ureter ligation. Unlabeled L-lysine administered simultaneously with L-[35S]cystine, in both the presence and absence or ureter ligation, enhanced the cellular accumulation of intracellular metabolic products of L-[35S]cystine. Simultaneous 35S cellular accumulation and L-cystine clearance studies were performed both in the presence and absence of L-lysine. L-Lysine enhanced cellular accumulation of 35S-products despite an accompanying increase in L-cystine clearance. The results are interpreted as evidence for a dissociation between cellular accumulation and transepithelial transport. This evidence for independent luminal transport and peritubular cellular accumulation could explain the apparent paradox in the disease cystinuria where there appears to be a luminal transport defect for L-cystine, but no defect for cellular accumulation of L-cystine metabolic products in vitro.

Authors

Warren E. Greth, Samuel O. Their, Stanton Segal

Mechanism of Effect of Prostaglandin E₁ on Renal Water Excretion

• Text
• PDF

Abstract

The present study examined the effect of prostaglandin E1 (PGE1) on renal water excretion in the anesthetized dog. Renal perfusion pressure was kept constant by adjustment of a suprarenal aortic clamp. In seven experiments the intravenous administration of PGE1 (7 μg/min) significantly increased urinary osmolality from 76 to 381 mosmol (P < 0.001) and decreased free water clearance from 2.2 to - 0.02 ml/min (P < 0.001). These effects promptly were reversed with cessation of the infusion. This antidiuretic effect occurred both in innervated and denervated kidneys and was not associated with changes in glomerular filtration rate, renal vascular resistance, or solute excretion rate. In 10 experiments in hypophysectomized dogs no effect of intravenous PGE1 on free water clearance and urinary osmolality was observed. The intrarenal administration of PGE1 (1 μg/min) to six water-loaded and two hypophysectomized dogs caused no systemic vascular changes and increased rather than decreased free water clearance (2.83 to 4.08 ml/min, P < 0.001). No significant change in urinary osmolality occurred. Glomerular filtration rate was not altered by the intrarenal infusion, but reversible changes in solute excretion rate and renal vascular resistance occurred. These results thus indicate that the antidiuresis associated with intravenous PGE1 is mediated primarily by the release of vasopressin rather than alterations in renal hemodynamics or solute excretion. The diuretic effect of intrarenal PGE1 occurs in the absence of vasopressin and is most likely mediated primarily by increased distal delivery of tubular fluid to the diluting segment of the nephron rather than changes in water permeability of the renal tubular epithelium.

Authors

T. Berl, R. W. Schrier

IgE Antibody Measurements in Ragweed Hay Fever RELATIONSHIP TO CLINICAL SEVERITY AND THE RESULTS OF IMMUNOTHERAPY

• Text
• PDF

Abstract

Specific IgE anti-ragweed antibodies (IgEAR) were measured over two years in two groups of highly sensitive patients treated (immunized) with either ragweed extract or placebo and in a third group of placebo-treated, relatively insensitive patients. The IgEAR on the patients' basophils were assessed by ragweed antigen E (AgE)-induced histamine release; blocking (IgG) antibodies were measured by their ability to inhibit AgE induced histamine release. These data were evaluated against the clinical severity of ragweed hay fever in each patient.

Authors

L. M. Lichtenstein, K. Ishizaka, P. S. Norman, A. K. Sobotka, B. M. Hill

Altered Lipid Metabolism in Human Platelets after Primary Aggregation

• Text
• PDF

Abstract

Thrombin and poly-l-lysine alter the incorporation of acetate, glycerol, and fatty acids into the lipids of washed human platelets. Both aggregating agents decrease the incorporation of acetate into all lipid classes other than free fatty acids. Similarly, glycerol incorporation into complex lipids is impaired by both thrombin and polylysine. Thrombin caused marked depression of the incorporation of palmitic acid into both lecithin and triglycerides. By contrast it enhanced the incorporation of oleic acid into lecithin, but not into triglycerides. The data suggest that the process of primary platelet aggregation is associated with a defect in the assembly of complex lipids.

Authors

Daniel Deykin

Measurement of the Third Component of Complement Bound to Red Blood Cells in Patients with the Cold Agglutinin Syndrome

• Text
• PDF

Abstract

The amount of the third component of complement (C3) bound to red cells of patients with the cold agglutinin syndrome was determined by a quantitative assay, measuring the fixation of the first component of complement by anti-C3. Abrupt reduction in the serum concentration of cold agglutinin by plasmapheresis markedly decreased the hemolytic rate, but the amount of C3 bound to circulating cells did not change appreciably. When this patient was transfused with normal cells. C3 accumulated on the transfused cells within 48 h to the level present on his own cells, but selective destruction of the transfused cells did not occur. When patients were subjected to acute cold stress, cell-bound C3 rose abruptly and intravascular hemolysis occurred. These studies suggest that most of the C3 detected on the circulating red cells of cold agglutinin patients is in an inactive form, and that the rate of attachment of C3 to the membrane is important in determining hemolysis.

Authors

Gerald L. Logue, Wendell F. Rosse, Jon P. Gockerman

Mechanism of Effect of Alpha Adrenergic Stimulation with Norepinephrine on Renal Water Excretion

• Text
• PDF

Abstract

The present study was undertaken to investigate the mechanism whereby alpha adrenergic stimulation with intravenous norepinephrine results in a water diuresis. Renal perfusion pressure was kept constant in all experiments by adjustment of a suprarenal aortic clamp. In hydropenic anesthetized dogs the intravenous infusion of norepinephrine (0.5 μg/kg per min) was associated with a mean decrease in urinary osmolality from 616 to 126 mosmol/kg (P < 0.001) which increased to 532 mosmol/kg (P < 0.001) after the infusion was discontinued. During the same period of time the mean free water clearance increased from -0.437 to 1.59 (P < 0.001) and then returned to -0.314 ml/min (P < 0.001) after cessation of the infusion. This diuretic effect occurred in both innervated and denervated kidneys and was not associated with an increase in glomerular filtration rate or solute excretion. Systemic arterial pressure increased from 121 to 142 mm Hg during the norepinephrine infusion. Studies were also performed in hypophysectomized animals receiving a constant infusion of either 80 μg/kg per min or 20-40 μU/kg per min of vasopressin. In these animals, intravenous norepinephrine was not associated with changes in either urinary osmolality or free water clearance. The intrarenal administration of norepinephrine, in doses comparable with those reaching the kidneys during the intravenous studies, also resulted in no significant change in either urinary osmolality or free water clearance in hypophysectomized animals receiving 20-30 μU/kg per min of vasopressin. These results thus indicate that the water diuresis associated with intravenous norepinephrine is mediated primarily by suppression of vasopressin release rather than by changes in renal hemodynamics, renal innervation, or an effect of norepinephrine on the water permeability of the tubular epithelium.

Authors

Robert W. Schrier, Tomas Berl

Autonomous Erythropoiesis during Erythroblastic Crisis of Chronic Myelocytic Leukemia

• Text
• PDF

Abstract

Two patients with chronic myelocytic leukemia who developed an erythroblastic rather than a myeloblastic phase were studied with respect to whether or not the megaloblastic erythropoiesis was subject to normal control mechanisms. After transfusion, no significant reduction was observed in the percentage of nucleated erythroid precursors or of proerythroblasts in marrow or in blood reticulocytes. In one of the two patients, ferrokinetics and urinary erythropoietin levels were studied and were also compatible with the conclusions that erythropoiesis was autonomous in this rare syndrome. Three patients with clinical pictures compatible with Di Guglielmo's syndrome were studied as controls. As has been reported previously, erythropoiesis in this syndrome appeared to be responsive to normal control mechanisms. These data suggest that these two clinically similar syndromes, erythroblastic crisis of chronic myelocytic leukemia and Di Guglielmo's syndrome may represent qualitatively different defects in hematopoietic stem cells.

Authors

C. H. Srodes, E. H. Hyde, D. R. Boggs

Deficiency of the Chemotactic Factor Inactivator in Human Sera with α₁-Antitrypsin Deficiency

• Text
• PDF

Abstract

As revealed by appropriate fractionation procedures, human serum deficient in α1-antitrypsin (α1-AT) is also deficient in the naturally occurring chemotactic factor inactivator. These serum donors had severe pulmonary emphysema. Serum from patients with clinically similar pulmonary disease, but with presence of α1-AT in the serum, showed no such deficiency of the chemotactic factor inactivator. When normal human serum and α1-AT-deficient human sera are chemotactically activated by incubation with immune precipitates, substantially more chemotactic activity is generated in α1-AT-deficient serum. These data indicate that in α1-AT-deficient serum there is an imbalance in the generation and control of chemotactic factors. It is suggested that the theory regarding development of pulmonary emphysema in patients lacking the α1-antitrypsin in their serum should be modified to take into account a deficiency of the chemotactic factor inactivator.

Authors

Peter A. Ward, Richard C. Talamo

Myelin from Human Peripheral Nerves QUANTITATIVE AND QUALITATIVE STUDIES IN TWO AGE GROUPS

• Text
• PDF

Abstract

Myelin in femoral nerve segments obtained at autopsy was isolated quantitatively by a series of discontinuous and continuous flotation procedures. The total amount of myelin isolated from these nerves was expressed as the sum of cholesterol, glycolipid, phospholipid, and protein and averaged 2.6±0.4 mg/g in a group aged 60-77 yr compared with 10.8±1.9 mg/g of nerve in a group aged 35-58 yr. The lower value in the older group remained apparent whether the myelin content was related to the whole nerve segment, its unit length or weight. This indicates that the decrease is an absolute one, not related to a change with aging in the nonmyelin content of nerve.

Authors

Norton Spritz, Harbhajan Singh, Barbara Geyer

Activation of Renal Cortical Adenylate Cyclase by Circulating Immunoreactive Parathyroid Hormone Fragments

• Text
• PDF

Abstract

Three distinct immunoreactive species of parathyroid hormone (PTH) are present in human serum. One has an estimated mol wt of 9,500 and probably represents glandular hormone, the second 7,000-7,500 mol wt, and the third 4,500-5,000 mol wt. In order to assess the biological activity of these circulating forms of PTH, we determined their ability to activate renal cortical adenylate cyclase. The 9,500 mol wt and 4,500-5,000 mol wt fractions produced four- to sixfold increases in cyclic 3′,5′-AMP accumulation above control; the 7,000-7,500 mol wt fraction was inactive. None of the fragments had any effects on phosphodiesterase activity. Antiserum to bovine PTH did not block the activation of adenylate cyclase by either the gragments or bovine PTH. The data suggest that a large proportion of circulating immunoreactive human PTH is biologically active and that the biologically and immunologically active sites of the hormone are distinct.

Authors

Janet M. Canterbury, Gerald S. Levey, Eric Reiss

Control of Thyroid Hormone Secretion in Normal Subjects Receiving Iodides

• Text
• PDF

Abstract

The administration of exogenous iodides (saturated solution of potassium iodide, SSKI) to normal male volunteers resulted in a significant decrease in the serum concentration of thyroxine (T4) and triiodothyronine (T3) and a significant increase in serum concentration of thyrotropin (TSH). During the control period (phase I), serum concentrations of T4 averaged 6.9±1.8 μg/100 ml (mean ±SD), T3 106±15 ng/100 ml, and TSH 3.7±1.3 μU/ml. During the administration of 1 drop of SSKI twice daily for 11 days (phase II), there was a small but significant decrease in the serum concentration of T4 and T3 (5.8±1.6 μg/100 ml and 91±19 ng/100 ml, respectively) and a small but significant increase in the serum concentration of TSH (6.0±3.5 μU/ml). During the administration of 5 drops of SSKI twice daily (phase III) over the following 12-19 days, these changes persisted, except for a small increase in the serum concentration of T3 (97±20 ng/100 ml), which was statistically significant when compared to values obtained during phase II. Values returned to control levels 14 days after withdrawal of SSKI. Almost all these observed changes took place within the limits of the normal range. It is postulated that, in euthyroid individuals, iodides specifically inhibit release of T4 and probably of T3. The resulting slight decrease in values for serum T4 and T3 elicits a small increase in TSH secretion which, it is postulated, antagonizes the inhibition of hormone release induced by iodides. As a result, a new equilibrium is reached which maintains the euthyroid state.

Authors

Apostolos G. Vagenakis, Patricia Downs, Lewis E. Braverman, Albert Burger, Sidney H. Ingbar