Showing papers on "Serum albumin published in 1979"

Implications of Malnutrition in the Surgical Patient

Abstract: • The substantial prevalence of malnutrition in the hospitalized patient population has only been recently recognized. Preoperative nutritional and immunological assessment was performed prospectively on admission in 64 consecutive surgical patients. Factors measured included weight loss, triceps skinfold, midarm muscle circumference, creatinine-height index, serum albumin level, serum transferrin level, total lymphocyte count, serum complement level, serum immunoelectrophoresis, lymphocyte T rosettes formation, neutrophil migration, and delayed hypersensitivity. Using these criteria for malnutrition, 97% of the patients had at least one abnormal measurement and 35% had at least three abnormal measurements. Patients were monitored for complications during their hospital course. Serum albumin level, serum transferrin level, and delayed hypersensitivity reactions were the only accurate prognostic indicators of postoperative morbidity and mortality. Substantial unrecognized malnutrition exists in the surgical patient population. An isolated indicator of malnutrition should be interpreted with caution. The visceral protein compartment (serum albumin and serum transferrin levels and delayed hypersensitivity) is the most accurate prognostic indicator of postoperative morbidity and mortality. Perioperative nutritional support may reduce operative morbidity and mortality in the malnourished operative candidate. ( Arch Surg 114:121-125, 1979)

Transport of Steroid Hormones Through the Rat Blood-Brain Barrier. Primary Role of Albumin-Bound Hormone

Abstract: These studies were undertaken to investigate (a) the permeability properties of the blood-brain barrier (BBB) to the major gonadal and adrenal steroid hormones, and (b) the role of the binding proteins of plasma (albumin and specific globulins) in the regulation of BBB steroid hormone transport. The permeability of the BBB to [(3)H]-labeled progesterone, testosterone, estradiol, corticosterone, aldosterone, and cortisol, was measured relative to [(14)C]butanol, a freely diffusable reference, in the barbiturate anesthetized rat using a tissue sampling-single injection technique. The isotopes were rapidly injected in a 200-mul bolus of Ringer's solution (0.1 g/dl albumin) via the common carotid artery and the percent extraction of unidirectional influx of hormone was determined after a single pass through brain: progesterone, 83+/-4%; testosterone, 85+/-1%; estradiol, 83+/-3%; corticosterone, 39+/-2%; aldosterone, 3.5+/-0.8%; and cortisol, 1.4+/-0.3%. The selective permeability of the BBB was inversely related to the number of hydrogen bonds each steroid formed in aqueous solution and directly related to the respective 1-octanol/Ringer's partition coefficient. When the bolus injection was 67% human serum, >95% of the labeled steroid was bound as determined by equilibrium dialysis. However, the influx of the steroids through the BBB was inhibited by human serum to a much less extent than would be expected if only the free (dialyzable) hormone was transported; progesterone, estradiol, testosterone, and corticosterone transport was inhibited 18, 47, 70, and 85% respectively, or in proportion to the steroid binding to plasma globulins. Rat serum (67%) only inhibited the transport of these four hormones, 0, 13, 12, and 69%, respectively, reflecting the absence of a sex hormone-binding globulin in rat plasma. However, neonatal rat serum (67%) inhibited progesterone, testosterone, and estradiol transport 0, 0, and 91%, respectively, consistent with the presence of an estradiol-binding protein in neonatal rat serum. The binding of steroid hormone to bovine albumin in vitro (as determined by equilibrium dialysis) was compared to albumin binding in vivo (as determined by the single injection technique). The ratio of apparent dissociation constant in vivo, K(D)(app), to the in vitro K(D) was: >>200 for progesterone, >200 for testosterone, 120 for estradiol, and 7.7 for corticosterone. Assuming the steady-state condition, the K(D)(app)/K(D) was found to be proportional to the BBB permeability for each steroid. These data demonstrate (a) the selective permeability properties of the BBB to the major steroid hormones is proportional to the tendency of the steroid to partition in a polar lipid phase and is inversely related to the number of hydrogen bond-forming functional groups on the steroid nucleus; (b) the presence of albumin in serum may bind considerable quantities of steroid hormone, but exerts little inhibitory effects on the transport of steroids into brain, whereas globulin-bound hormone does not appear to be transported into brain to a significant extent. Therefore, the hormone fraction in plasma that is available for transport into brain is not restricted to the free (dialyzable) fraction, but includes the larger albumin-bound moiety.

The rat serum albumin gene: analysis of cloned sequences.

Abstract: The rat serum albumin gene has been isolated from a recombinant library containing the entire rat genome cloned in the lambda phage Charon 4A. Preliminary R-loop and restriction analysis has revealed that this gene is split into at least 14 fragments (exons) by 13 intervening sequences (introns), and that it occupies a minimum of 14.5 kilobases of genomic DNA.

Enhanced nonenzymatic glucosylation of human serum albumin in diabetes mellitus

Abstract: Use of an ion exchange chromatographic method and a colorimetric method with thiobarbituric acid showed that levels of nonenzymatically glucosylated serum albumin were increased in patients with poorly controlled diabetes mellitus compared to controls. The two methods correlated well (r = 0.99) and clearly discriminated between normal and poorly controlled diabetic populations. The levels of glycosylated hemoglobin were also measured in both populations. Several patients apparently in good control based on glycosylated hemoglobin measurements were found to have increased levels of glycosylated albumin. Because albumin has a shorter circulating half-life than does the human erythrocyte, the plasma concentration of glucosylated albumin should be expected to reflect short-term control of hyperglycemia in diabetes. The studies reported here suggest that the level of glucosylated albumin may indeed be a sensitive indicator of moderate hyperglycemia and of early glucose intolerance.

Albumin-deficient rat mutant

Abstract: An analbuminemic colony was established from Sprague-Dawley rats. Analbuminemia was inherited as an autosomal recessive trait. The rates of growth and reproduction of the mutant rats were no different from those of normal rats. Biochemically, the mutant was characterized by an extraordinarily low serum albumin content and a hyperlipidemia. Total serum protein in the mutant rat was similar to that of control Sprague-Dawley rats, with increased globulin. Serum cholesterol was inversely correlated with a decrease in albumin; the correlation coefficient for ablumin was --.92. These mutant rats may serve as a model of human familial analbuminemia and may also be useful in elucidating the functional roles of albumin.

Fetal phenotypic expression by adult rat hepatocytes on collagen gel/nylon meshes.

Abstract: Hepatocytes from adult rats were maintained in primary culture for up to 10-13 days on nylon meshes coated with a thin layer of rat tail collagen gel. Their ultrastructure closely resembled that of the liver parenchymal cell in vivo, but hepatocytes in late culture exhibited a pronounced buildup of microfilaments beneath their apical cell surface. Hepatocytes in early and late cultures secreted albumin, transferrin, and alpha1-acid glycoprotein into the medium; they exhibited a 7- to 10-fold induction of tyrosine aminotransferase activity by dexamethasone; and they expressed an alkaline phosphatase that was similar to that of normal rat liver with respect to its inhibition by the liver enzyme inhibitor L-homoarginine. In addition, the hepatocytes in culture demonstrated phenotypic changes characteristic of fetal liver parenchymal cells. These changes, which paralleled an increase in DNA synthesis, included the expression of and linear increase in the activity of the fetal liver cell enzyme gamma-glutamyl transpeptidase, an increased production of alpha1-fetoprotein, and a change in the substrate specificity of fructose-bisphosphate aldolase to that of the fetal liver isozyme.

Reduced Serum Albumin Concentration in the Elderly: A Report from the Boston Collaborative Drug Surveillance Program

Abstract: The relation of serum albumin concentration to age was assessed in a series of hospitalized medical patients. Those with disease states (e.g., dysproteinemia, renal insufficiency, hepatic dysfunction, malnutrition) potentially associated with abnormal serum albumin levels were excluded, leaving a study population of 11,090 patients. The mean serum albumin concentration fell progressively with each decade of age, from 3.97 gm/100 ml in subjects aged less than 40, to 3.58 gm/100 ml in those aged 80 or older (F greater than 50.0, P less than .001). The percentage of patients with a normal serum albumin level (4.0 gm/100 ml or higher) also decreased progressively with age, whereas the frequency of a low serum albumin level increased with age. Sex, primary diagnosis, blood urea nitrogen concentration, duration of hospitalization, and geographic location of the hospital did not influence the findings. The reduced serum albumin concentration in the elderly could contribute to age-dependent changes in the clinical effects of certain albumin-bound drugs, since pharmacologic activity can be influenced by the extent of albumin binding, in turn related to albumin concentration.

Mechanisms of Edema Formation in Myxedema — Increased Protein Extravasation and Relatively Slow Lymphatic Drainage

Abstract: We assessed extravascular accumulation of albumin and fluid in primary myxedema by measuring metabolic turnover and transcapillary escape of 131I-labeled human albumin in seven patients. In the hypothyroid state, we found a low plasma volume (P less than 0.05), a reduced rate of albumin synthesis and catabolism (P less than 0.01), an increased transcapillary escape rate of albumin (P less than 0.01), a remarkable increase in the extravascular mass of albumin (1500 micronmol; P less than 0.01) and a longer mean transit time through the extravascular spaces in primary myxedema than in other states of generalized edema (P less than 0.05). All variables returned to normal during l-thyroxine treatment. The extravascular accumulation of albumin, and presumably of all other plasma proteins, is important in the generalized edema typically found in myxedema. Inadequate lymphatic drainage may also explain the formation of exudates in the serous cavities that are well known in myxedema.

Surface-associated host proteins on virulent Treponema pallidum.

Abstract: A surface coat of host serum proteins was detected on virulent Treponema pallidum by sodium dodecyl sulfate-gel electrophoresis. The loosely associated serum proteins could be removed by repeated washings in a protein-free medium. Washed T. pallidum retained the ability to readsorb numerous host proteins from rabbit serum as well as iodinated rabbit or human albumin. In addition, various avidly associated host serum proteins including albumin, alpha(2)-macroglobulin, transferrin, ceruloplasmin, immunoglobulin G, immunoglobulin M, and C3 were identified on the outer envelope of washed treponemes by an immunoadsorbent technique with protein A-bearing staphylococcus. Hyaluronidase treatment did not remove the avidly associated host proteins from the surface of washed treponemes, whereas trypsin treatment resulted in decreased levels of agglutination. Electrophoretic patterns of trypsin-treated treponemes showed that treponemal proteins as well as adsorbed host proteins were released concurrently by protease digestion. Reacquisition studies involving alpha(2)-macroglobulin and transferrin suggested the presence of noncompetitive binding sites for serum proteins on the treponemal outer envelope. Finally, differences among the T. pallidum preparations from individual rabbits with respect to incorporation of [(35)S]methionine, extent of agglutination with antisera, and length of time required for removal of avidly associated host proteins by trypsin treatment indicated biological variability among the treponemal populations.

The effect of heat inactivation of serum on aggregation of immunoglobulins.

Abstract: Heating serum at 56 degrees is used to inactivate complement in several immunological assays. During heating, both heat-labile and heat-stable anticomplementary activity (ACA) develop. While heat-labile ACA can be completely inactivated, heat-stable ACA increases progressively with continued heating. Heat-stable ACA develops in deaggregated IgG and in normal, but not in hypogammaglobulinaemic, human and porcine serum heated at 56 degrees suggesting that this ACA is due to formation of immunoglobulin aggregates. These aggregates would produce false-positive tests for immune complexes and could inhibit a variety of cell-mediated reactions in assays which incorporate heat-inactivated serum. Other temperatures were tested to determine whether endogenous haemolytic activity could be destroyed without forming immunoglobulin aggregates. At 53 degrees both endogenous haemolytic activity and heat-labile ACA were inactivated and formation of heat-stable ACA in normal serum was minimal. ACA, however, could be induced in deaggregated IgG at 53 degrees. Moreover, the degree of heat-induced aggregation of IgG in vitro at either temperature was directly proportional to IgG concentrations and inversely related to albumin concentrations. Thus, pathological sera with these protein alterations might form more aggregates during heating than normal sera. These data suggest the following: (1) heat inactivation of complement at 53 degrees for 90 min is preferable to the traditional 56 degrees; (2) in any assay where immunoglobulin aggregates might interfere, normal serum may be an inadequate control and correlations will need to be made between serum IgG and albumin concentrations and the results obtained in these assays.

Specific absorption of human serum albumin, immunoglobulin A, and immunoglobulin G with selected strains of group A and G streptococci.

Abstract: Five gram-positive bacterial strains were selected for absorption studies of human serum samples. Strain AR1 (group A, M-type 1) and G148 (group G), with strong immunoglobulin G (IgG) binding capacities, and strain AW43 (group A, M-type 60), binding both IgA1 and IgA2, were compared with Staphylococcus aureus Cowan I and with Staphylococcus epidermidis L603. Both AR1 and G148 were capable of completely absorbing out serum IgG. In contrast, S. aureus Cowan I left a fraction unabsorbed, as expected from its known lack of IgG3 binding. Strain AW43 absorbed out all serum IgA, using a 10-microliter bacterial pellet for 20 microliter of serum. Serum IgM levels were slightly reduced by S. aureus Cowan I absorption. On the basis of the experiments, a bacterial mixture was designed consisting of S. aureus Cowan I and group A streptococcus strains AR1 and AW43, with absorption characteristics suitable for use in discriminating between early IgM and late IgG and IgA immune responses in routine serological work. A new type of bacteria-mammalian protein binding was discovered. Human serum albumin was completely absorbed out by strain G148 and to a lesser extent by strain AR1 and AW43. S. aureus Cowan I and S. epidermidis were negative. The binding capacity of G148 for albumin equalled that of Cowan I for IgG. The binding pattern of albumin to the strains was different from those of IgG, IgA, IgM, fibrinogen, haptoglobin, or aggregated beta 2-microglobulin and therefore seems to represent another type of bacterial-mammalian interaction with a specific albumin receptor on the surface of streptococci.

Interpretation of serum total calcium: effects of adjustment for albumin concentration on frequency of abnormal values and on detection of change in the individual.

Abstract: Serum total calcium was measured in 1693 patients during a four-month period. We examined the effects of adjustment for albumin concentration on the interpretation of single measurements of serum total calcium and on the variation of series of measurements in individual patients. Markedly abnormal total calcium concentrations--2.75 mmol/l (11.0 mg/100 ml) or more, or 2.00 mmol/l (8.0 mg/100 ml) or less--were found in 115 patients, but only 24 (21%) remained markedly abnormal after adjustment for albumin. Three patients, two with malignant disease and one with primary hyperparathyroidism, had significant hypercalcaemia which was masked by hypoalbuminaemia. The serum total calcium measured on a subsequent occasion had changed 0.15 mmol/l (0.6 mg/100 ml) or more in 60 patients, but after adjustment for albumin this number was reduced to 27 (45%). The within-person standard deviation for serum total calcium was calculated in 26 patients with normal mean adjusted calcium concentrations who had had six or more sequential measurements. The mean standard deviation was 0.148 mmol/1 (0.59 mg/100 ml) and, after adjustment for albumin, this was reduced to 0.100 mmol/1 (0.40 mg/100 ml). We conclude that adjustment of serum total calcium concentration for albumin is essential to detect abnormal values and to assess changes in a value.

Transcapillary passage of albumin, effects of tissue cooling and of increases in filtration and plasma colloid osmotic pressure.

Abstract: 'Initial' clearance of radiolabelled serum albumin was measured in the perfused, maximally vasodilated muscle vascular bed of rat hindquarters during tissue cooling, during increases in filtration and during changes in serum colloid osmotic pressure. Albumin clearance during ordinary serum perfusion at isogravimetry amounted to 0.03 ml/min times 100 g, increasing linearly with filtration rate to some 0.07 ml/min times 100 g at 0.5 ml/min times 100 g of filtration. During cooling from 36 degrees C to 14 degrees C both CFC and initial albumin clearance at isogravimetry decreased some 40%, in due proportion to the increased viscosity of the fluid. Increases of the colloid osmotic pressure of the perfusate correspondingly increased both the isogravimetric capillary pressure and 'initial' albumin clearance during isogravimetry.--It is concluded that even during isogravimetry the transmicrovascular albumin passage is to about 70 per cent due to filtration, and only some 30 per cent of transport at ordinary serum colloid osmotic pressure takes place by diffusion, both events presumably via 'large pores'. There was no evidence that transendothelial vesicular transport should to any significant extent contribute to the passage of albumin from vessels to tissue.

Diethylstilbestrol and estradiol binding to serum albumin and pregnancy plasma of rat and human.

Abstract: The equilibrium binding of diethylstilbestrol (DES) and 17β-estradiol (E2) to plasma proteins has been characterized. DES exhibits a 10- to 20-fold greater binding affinity index for bovine serum albumin and rat plasma than E2. As expected, E2 gave high values for binding to plasma from pregnant mice or rats, reflecting the presence of α-fetoprotein. DES bound to these samples as it did to bovine serum albumin and rat plasma. These results suggested that DES interacts weakly with α-fetoprotein. This was verified by Scatchard plots of DES and E2 binding to rat and human pregnancy plasma. High affinity, low capacity binding was demonstrated with E2 but not with DES. The significantly lower binding of DES suggests that increased delivery of DES to the fetus may be at least partially responsible for the transplacental toxicity and carcinogenicity of DES.

Relationship of Free and Total Calcium in Hypercalcemic Conditions

Abstract: An assessment of free and total calcium measurements was made in 691 patients with suspected hypercalcemia or disorders often associated with hypercalcemia. In 18.9% of the 1049 specimens analyzed from nine different patient groups, a different impression of hypercalcemia was obtained depending on whether the free or total calcium was considered. Analysis of the ratio of free to total calcium indicated that there are two main factors which influence the distribution of calcium in the serum of hypercalcemic patients: the concentrations of albumin and parathyroid hormone. A lowered albumin concentration accounted for the altered distribution of calcium in patients with malignancies and partially accounted for the altered distribution in patients postrenal transplantation. In patients with confirmed primary hyperparathyroidism a higher ratio of free to total calcium was found, which could not be explained by alterations in protein, albumin, pH, or CO2 content but was related to parathyroid hormone concentration. Free calcium appears to be a slightly better indicator of elevated calcium states than total calcium. Measurements of free calcium should be particularly useful in patients with altered albumin concentration, with multiple myeloma in whom a calcium-binding protein could be present, after renal transplantation, and with suspected hyperparathyroidism and normal or slightly elevated total calcium values.

The maintenance of motility and the surface properties of epididymal spermatozoa from bull, rabbit and ram in homologous seminal and epididymal plasma.

Abstract: Epididymal spermatozoa from bull, rabbit and ram were incubated in homologous epididymal plasma or seminal plasma in a buffered saline-based medium with or without serum albumin. The spermatozoa were either diluted directly into the medium or were washed first. No effect of washing was observed on the subsequent reaction of the cells to the different media. A considerable proportion of the populations of epididymal spermatozoa survived (i.e. continued to exhibit motility) for up to 22 h at 30 degrees C in the simple saline-based medium. Initially epididymal plasma had a slight stimulatory effect on sperm motility in ram and bull but it had no effect on sperm survival in any of the 3 species. Seminal plasma stimulated motility markedly in ram initially, but in all 3 species seminal plasma was detrimental to survival: in ram even a 15-min exposure to the fluid reduced survival. Serum albumin also stimulated motility; it delayed, but did not prevent, the detrimental effect of seminal plasma, although it had no effect itself on survival. The effects of epididymal plasma, seminal plasma and serum albumin on surface properties of epididymal spermatozoa, i.e. agglutination, sticking-to-glass and eosinophilia, were also noted. These varied between species and there was no correlation between these effects and the effects on motility and survival.

Erythrocyte Binding Properties of Streptococcal Lipoteichoic Acids

Abstract: The lipoteichoic acids (LTA) of gram-positive bacteria are known to bind spontaneously to a variety of animal cell membranes. We investigated the biological and biochemical characteristics of the binding of LTA of Streptococcus pyogenes and S. faecalis to human and sheep erythrocytes. The kinetics of the binding of the radiolabeled LTA ([3H]LTA) from each of these organisms to erythrocytes was similar. The dissociation constants for sheep and adult human erythrocytes were 1.6 μM and 4.5 μM, respectively, whereas that of human cord blood erythrocytes was approximately 10-fold higher, 31 μM. The number of binding sites for sheep erythrocytes was calculated to be 7.2 × × 106 per cell, and that of human erythrocytes, 29 × 106 per cell. Binding was reversible. More than 50% of bound [3H]LTA was displaced from erythrocytes by a 50-fold excess of unlabeled LTA. LTA prepared from heterologous species of gram-positive bacteria were all inhibitory to the binding of [3H]LTA whether derived from S. pyogenes or from S. faecalis. Among a number of potential receptor analogues and other inhibitors tested, including serum albumin, gangliosides Gm2 and Gm3, lipopolysaccharide of gram-negative bacteria, and various sugars, only albumin and the gangliosides significantly inhibited LTA binding. Trypsin or neuraminidase treatment of erythrocytes had no effect on LTA binding. Deacylation of [3H]LTA abolished binding ability and binding was restored by esterification of the deacylated material with stearoyl chloride, indicating that ester-linked lipids are necessary for membrane binding.

Transferrin can replace serum for in vitro growth of mitogen‐stimulated T lymphocytes

Abstract: Activation of human T cells by mitogens was compared in cultures containing serum, human serum albumin or purified human transferrin as growth support. The mitogenic effect of the lectins leucoagglutinin, concanavalin A and Wistaria floribunda agglutinin was measured as incorporation of [3H]thymidine into the cellular DNA of the lymphocytes. Three different preparations of transferrin were all able to fully substitute serum or serum albumin as growth promotors, when present at concentrations of 10 microgram/ml or more. A small contamination of transferrin in the human serum albumin preparations used was shown to be responsible for their growth-supporting effect, while no need for the presence of albumin itself could be demonstrated.