Showing papers on "Blood proteins published in 1984"
TL;DR: A rapid one-stage clotting assay for protein S to quantitate the level of protein S in their plasma is developed and suggests that protein S deficiency may result in recurrent thrombotic disease.
Abstract: Recent studies have demonstrated that protein C deficiency is associated with recurrent familial thrombosis In plasma, activated protein C functions as an anticoagulant This anticoagulant response requires a vitamin K-dependent plasma protein cofactor, referred to as protein S Since the anticoagulant activity of activated protein C is dependent on protein S, we hypothesized that patients lacking functional protein S might have associated thrombotic disease Two related individuals with otherwise normal coagulation tests are described whose plasma is not effectively anticoagulated with activated protein C Addition of purified human protein S to their plasma restores a normal anticoagulant response to activated protein C We have developed a rapid one-stage clotting assay for protein S to quantitate the level of protein S in their plasma Plasma is depleted of protein S by immunoadsorption with immobilized antiprotein S antibodies The resultant plasma responds poorly to activated protein C, but is effectively anticoagulated in a dose-dependent fashion upon addition of purified protein S or small quantities of plasma The affected individuals possess less than 5% protein S activity Using Laurell rockets, protein S antigen was detected in the plasma but was at reduced levels of 13 and 18% in the two individuals When the barium eluate of the patient plasma was chromatographed on quaternary aminoethyl Sephadex, a single peak of protein S antigen devoid of protein S anticoagulant cofactor activity was detected early in the chromatogram In contrast, the barium eluate from normal donors separated into two peaks, one emerging early and also devoid of anticoagulant cofactor, and the second peak with anticoagulant activity emerging later The first peak of protein S antigen, from both the normal donor and the patient, chromatographed in the region of the complement component C4-binding protein-protein S complex These studies suggest that protein S deficiency may result in recurrent thrombotic disease
602 citations
TL;DR: As a first step in studying the biosynthesis of these proteins and elucidating their role(s) in normal development and in tumorigenesis, isolated and sequenced cDNAs prepared from adult human liver mRNA which encode the precursors to IGF-I and -II are reported.
Abstract: The insulin-like growth factors (IGF) I and II are single-chain serum proteins of 70 and 67 amino acids, respectively, which are synthesized by the liver and possibly other tissues. They are probably required for normal fetal and postnatal growth and development. They also stimulate the growth of cultured cells, possibly by controlling the progression through the G1 phase of the cell cycle. In contrast to IGF-II whose concentration does not vary during postnatal development, the serum levels of IGF-I increase several-fold to adult levels during puberty. The serum concentration of IGF-I is a sensitive monitor of growth hormone levels and is decreased in individuals with growth hormone deficiency and elevated in those with growth hormone-secreting tumours. As a first step in studying the biosynthesis of these proteins and elucidating their role(s) in normal development and in tumorigenesis, we have isolated and sequenced cDNAs prepared from adult human liver mRNA which encode the precursors to IGF-I and -II. We report here the sequence of a cDNA encoding a 180-amino acid protein which is the precursor to IGF-II.
319 citations
Journal Article•
TL;DR: Serum proteins from hepatectomized or control rats were separated by gel permeation chromatography and assayed for stimulation of hepatocyte proliferation in primary cultures of hepatocytes, and two peaks of activity were seen in the areas of large and small molecular weight.
Abstract: Serum proteins from hepatectomized or control rats were separated by gel permeation chromatography and assayed for stimulation of hepatocyte proliferation in primary cultures of hepatocytes. Two peaks of activity were seen in the areas of large (>120,000) and small (<3,000) molecular weight. These activities are different from insulin, epidermal growth factor, or vasopressin and are empirically termed hepatopoietin A and B, respectively. The two activities interact in a synergistic manner to stimulate hepatocyte proliferation at rates comparable to that of the whole serum.
306 citations
TL;DR: In this article, the serine protease inhibitor diisopropyl fluorophosphate was applied to human polymorphonuclear granulocytes (PMNs) to minimize proteolytic destruction or modification of antimicrobial proteins derived from these granules.
Abstract: Acid (0.2 M sodium acetate, pH 4.0) extracts of granules recovered from disrupted human polymorphonuclear granulocytes (PMNs) exhibited in vitro antimicrobial activity against Salmonella typhimurium. To minimize proteolytic destruction or modification of antimicrobial proteins derived from these granules, we pretreated the PMNs with the serine protease inhibitor diisopropyl fluorophosphate. Fractionation of such extracts by carboxymethyl Sephadex and Sephadex G-75 chromatography resulted in the recovery of at least two antimicrobial, cationic proteins. These proteins differed substantially in antimicrobial activity, amino acid composition, and molecular weight (Mr, 37,000 and 57,000). As we have shown before (Shafer et al., Infect. Immun. 43:834-858), with unfractionated proteins, these two proteins exhibited diminished activity against a polymyxin B-resistant (PBr) mutant of S. typhimurium compared with their activity against the isogenic parental polymyxin B-sensitive (PBs) strain. Expression of the relevant mutation (prmA) in the PBr mutant decreases the electronegativity of lipid A, owing to increased 4-amino-4-deoxy-L-arabinosylation at the 4' phosphate residue (Vaara et al., FEBS Lett. 129:145-149). The data suggest that at least two different cationic proteins account for the antimicrobial capacity of extracts from human PMN granules. Moreover, the availability of anionic charges in the outer membrane of S. typhimurium due to free lipid A phosphates apparently dictates phenotypic levels of resistance to both of the cationic proteins extracted from human PMN granules.
218 citations
TL;DR: Comparing thymocyte-stimulating activities with the effects on plasma protein production, it is found some difference both between the conditioned media of epidermal cells and monocytes, and between the responses of the three hepatic cell systems.
207 citations
TL;DR: The data reported are in general agreement with the model of Vroman (12) for plasma-surface interactions which holds that initially adsorbed fibrinogen is later replaced by high molecular weight kininogen (HMWK), the rate of replacement depending on the relative activity of the surface in promoting coagulation.
Abstract: The adsorption of various plasma proteins to three solid surfaces has been studied as a function of plasma concentration. Albumin adsorption on glass showed no dependence on plasma concentration and increased to a plateau value on both polyethylene and siliconized glass. Immunoglobulin G (IgG) adsorption showed no dependence on plasma concentration on any surface. Fibrinogen adsorption increased with plasma concentration and then decreased, the maximum occurring at about 1% normal plasma concentration and varying somewhat with the surface. On glass the kinetics of fibrinogen adsorption was dependent on plasma concentration: at concentrations less than the adsorption maximum, the kinetics was conventional, with adsorption increasing onto a plateau; at concentrations greater than the adsorption maximum, kinetics curves also showed maxima the position of which shifted to longer times as plasma concentration decreased. These data are interpreted in terms of competitive adsorption between fibrinogen and other, as yet unidentified species in plasma. The data reported are in general agreement with the model of Vroman (12) for plasma-surface interactions which holds that initially adsorbed fibrinogen is later replaced by high molecular weight kininogen (HMWK), the rate of replacement depending on the relative activity of the surface in promoting coagulation.
182 citations
TL;DR: The development of a functional assay for plasma protein C is reported on, which measures the concentration of the activated protein C measured with a peptide substrate (S2366) in healthy volunteers and patients on stable oral anticoagulant treatment.
Abstract: Protein C is a vitamin K dependent protein involved in blood coagulation. A congenital deficiency in protein C antigen - which inherits as an autosomal dominant disorder - has been reported to be associated with a high risk for thrombo-embolic disease at relatively young age. In the present paper we report on the development of a functional assay for plasma protein C. In this assay protein C is adsorbed to Al(OH)3, eluted and activated by thrombin, after which the concentration of the activated protein C is measured with a peptide substrate (S2366). Normal values for protein C activity and protein C antigen were determined in healthy volunteers and patients on stable oral anticoagulant treatment. Protein C activity and antigen levels were compared in 28 patients from 9 different pedigrees with both congenital protein C deficiency and thrombotic disease. Two types of protein C deficiency could be recognized: in type I the deficiency is due to the absence or reduced presence of protein C molecules, while in type II the deficiency is caused by the presence of an abnormal protein C molecule with strongly reduced functional activity.
169 citations
TL;DR: Results suggested that fibrinogen adsorption from more complex mixtures such as plasma should also be strongly dependent on total concentration, and that competitive effectiveness is expected to increase as unoccupied surface adsorptive sites become less frequent.
Abstract: The strong effect of protein adsorption on blood and tissue compatibility is well known. Little is presently known about the mechanisms which control the composition of the adsorbed protein layer which forms upon exposure of surfaces to mixtures of proteins. Reexamination of the ability of hemoglobin to inhibit the adsorption of 125I fibrinogen to polyethylene revealed that the inhibition was strongly dependent on the fibrinogen concentration. These results suggested that fibrinogen adsorption from more complex mixtures such as plasma should also be strongly dependent on total concentration. Fibrinogen adsorption from plasma was found to be maximal at intermediate plasma concentrations, and was reduced at both low and high plasma concentrations. The plasma concentration at which this maximum occurred was 10% for polytetrafluoroethylene, 1% for polyethylene, and 0.1% for glass. The unusual concentration dependence is attributed to mass action effects on the competitive adsorption of proteins, specifically that competitive effectiveness is expected to increase as unoccupied surface adsorptive sites become less frequent. Analogous effects of adsorption time on competitive adsorption are also predicted due to the changing concentration at the interface as the buffer is gradually replaced by protein solution. These mass action effects are very similar to previous qualitative observations by Vroman and are therefore dubbed the " Vroman effect".
161 citations
TL;DR: Hepatocytes from normal rats synthesized proteins in relative amounts which were similar to the relative proportions of the same proteins in the plasma of turpentine-injected animals, suggesting that both activities probably reside with distinct molecular species in the preparations of human cytokines.
Abstract: Hepatocytes were isolated from adult livers and cultured for periods of up to 5 days as monolayers at an initial density of 10(6) cells/10cm2 in Williams E medium containing insulin, dexamethasone and 5% foetal-calf serum. The daily production of 11 plasma proteins was measured by electroimmunoassay and compared with the concentrations of the same proteins in the plasma of normal rats and of those with experimental inflammation. Hepatocytes from normal rats synthesized proteins in relative amounts which were similar to the relative proportions of the same proteins in the plasma of turpentine-injected animals. The pattern changed only slowly during 5 days in culture, but it did so profoundly either when the medium was devoid of dexamethasone or when human cytokines (from endotoxin-stimulated monocytes or unstimulated human squamous-carcinoma cell line COLO-16) were added. The cytokines consistently increased the synthesis of alpha 2-macroglobulin and fibrinogen and depressed that of albumin; variable increases in the synthesis of alpha 1-acute-phase globulin, alpha 1-acid glycoprotein, haptoglobin and alpha 1-proteinase inhibitor, and variable decreases in transferrin synthesis, were seen, whereas the synthesis of antithrombin III, alpha 1-macroglobulin and prothrombin remained virtually unaffected. The cytokine effects on protein synthesis required the presence of dexamethasone. The hepatocyte-stimulating activity derived from monocytes chromatographed on Sephadex G-100 corresponding to 30 000 Da, as opposed to the lymphocyte-activating factor, which was eluted as a molecule of approx. 15 000 Da. This suggests that both activities probably reside with distinct molecular species in the preparations of human cytokines.
150 citations
TL;DR: Results suggest that the conversion of PGD2 to this product is catalyzed by the enzymatic action of a plasma protein, probably serum albumin.
Abstract: Incubation of prostaglandin D2 (PGD2) with human plasma yielded a product that has been identified as 9-deoxy-9,10-didehydro-12,13-didehydro-13,14-dihydro-PGD2 (9-deoxy-delta 9, delta 12-13,14-dihydro-PGD2). The identification was based on mass spectrometry, UV spectrometry, mobilities and retention time on TLC and HPLC, and NMR. The conversion of PGD2 to this product was dependent on the incubation time and the amount of plasma added to a reaction mixture and was abolished by prior boiling. The conversion rate of PGD2 to this metabolite was 0.03 nmol/min per mg of protein of whole plasma at pH 8.0 at 37 degrees C. Similar conversion was also found by incubating PGD2 with human serum albumin added at the concentration found in plasma. These results suggest that the conversion of PGD2 to this product is catalyzed by the enzymatic action of a plasma protein, probably serum albumin. The biological activities of this compound were examined in several systems. It showed negligible activity in inhibition of human platelet aggregation and relaxation of rabbit stomach strip. On the other hand, it exhibited a three times stronger inhibitory activity (IC50, 1.8 microM) than PGD2 (IC50, 5 microM) on the growth of L-1210 cultured cells.
148 citations
TL;DR: Functional protein C levels correlate well with immunologic levels of the protein in the patient groups studied, and Heparin enhances the rate ofactivated protein C inhibition, as monitored by recovery of activated protein C by immunoadsorption.
TL;DR: The two tested strains of Bacteroides gingivalis degraded most serum proteins, including the plasma proteinase inhibitors alpha-1-antitrypsin and alpha-2-macroglobulin, but were able to inactivate the capacity of serum to inhibit the activity of trypsin.
Abstract: Various strains of black-pigmented Bacteroides species were grown on horse blood agar and suspended in human serum. After various times of incubation the effect of the bacteria on the serum was evaluated by polyacrylamide gel electrophoresis and "rocket" immunoelectrophoresis. The formation of trichloroacetic acid-soluble material in the suspensions and the capacity of the treated sera to inhibit the activity of trypsin were also determined. The two tested strains of Bacteroides gingivalis (W83, H185) degraded most serum proteins, including the plasma proteinase inhibitors alpha-1-antitrypsin and alpha-2-macroglobulin. They did not, however, degrade alpha-1-antichymotrypsin. Bacteroides intermedius NCTC 9336, Bacteroides asaccharolyticus NCTC 9337, and an asaccharolytic oral strain different from B. gingivalis (BN11a-f) did not degrade the plasma proteinase inhibitors. These strains were, however, able to inactivate the capacity of serum to inhibit the activity of trypsin.
01 Jan 1984
TL;DR: A tracer-kinetic model is used to analyze in vivo initial extraction data on BBB transport of protein-bound steroid hormones, thyroid hormones, and lipophilic amine drugs, indicating that the rate of ligand dissociation from the plasma protein is accelerated in the capillary bed relative to the in vitro situation.
Abstract: Previous studies have shown that the fraction of hormone or drug that is plasma protein bound is readily available for transport through the brain endothelial wall, i.e., the blood-brain barrier (BBB). To test whether these observations are reconcilable with the free-hormone hypothesis, a tracer-kinetic model is used in the present investigations to analyze in vivo initial extraction data on BBB transport of protein-bound steroid hormones (dihydrotestosterone, testosterone, estradiol, and corticosterone), thyroid hormones (triiodothyronine), and lipophilic amine drugs (propranolol). The plasma proteins used are bovine albumin and human orosomucoid. Transport data was fit to a modification of the Kety-Renkin-Crone equation of capillary physiology; the modified equation incorporates the principles of both capillary physiology and plasma protein-ligand mass action binding relationships. In most cases, the experimental data is best fit to the model equation when the apparent in vivo dissociation constant, KDa, of the ligand protein binding reaction increases to values that are 5- to 50-fold greater than the in vitro dissociation constant, KD. This result indicates that the rate of ligand dissociation from the plasma protein is accelerated in the capillary bed relative to the in vitro situation. It is hypothesized that the major factor leading to the rapid transport in vivo of protein-bound ligands into tissues such as brain is an endothelial-induced decrease in the affinity of the plasma protein for the ligand. Under these conditions, the amount of plasma ligand available for tissue clearance in vivo parallels the protein-bound fraction, not the free hormone.
TL;DR: Parameters of secretion of IgA and several other plasma proteins from the jejunal mucosa were investigated in 11 individuals who had a normal distribution of Ig-containing cells in the lamina propria and in one patient who was totally deficient inJejunal IgAand IgM plasmacytes, suggesting an additional role of either local gut synthesis and/or active transepithelial transport.
Abstract: Parameters of secretion of IgA and several other plasma proteins from the jejunal mucosa were investigated in 11 individuals who had a normal distribution of Ig-containing cells in the lamina propria and in one patient who was totally deficient in jejunal IgA and IgM plasmacytes. Jejunal samples were collected during segmental gut perfusion. The following results were obtained: (a) The secretion of polymeric IgA (p-IgA, mean equals 217 micrograms/40 cm per min) exceeded those of albumin (132 micrograms), IgG (35 micrograms), and monomeric IgA (m-IgA, 15 micrograms, or 6.4% of total IgA). About 35% of IgA was IgA2 in the jejunal secretion, compared with approximately 23% in serum. This closely corresponds to the 35 and 24% of IgA2 plasmocytes in jejunal mucosa and peripheral lymph nodes, respectively. (b) For each protein, a relative coefficient of excretion (RCE) was calculated (jejunum to serum concentration ratio expressed relative to that of albumin). RCEs of 1.41 for orosomucoid, 1.0 for albumin, 0.83 for IgG, and 0.74 for IgE and, in the deficient patient, of 0.64 for m-IgA and 0.016 for IgM were obtained. This was inversely related to the molecular weight of these proteins and indicated their predominantly passive transport into the jejunum. However, in normal individuals, the RCE of transferrin (approximately 1.11 greater than 1, P greater than 0.05), alpha 2-macro globulin (approximately 0.77), m-IgA (approximately 1.98), and p-IgA (approximately 218) exceeded the value expected from simple seepage from plasma, thus pointing to an additional role of either local gut synthesis and/or active transepithelial transport. (c) Approximately 98% of p-IgA, approximately 99% of IgM, and approximately 68% of m-IgA in jejunal secretions were derived from local production in the gut wall, as determined by 125I-p-IgA specific activities and/or by comparison between the RCE values of the deficient patient to the values of controls. Therefore, the jejunal production of p-IgA (approximately 312 mg/d per 40 cm vs. approximately 54 mg/d from bile) contributes the majority of upper intestinal IgA in humans. The active transport of plasma p-IgA across the intestinal mucosa (approximately 0.08 mg/40 cm per kg per d) contributes less than 2% of the total amount of p-IgA (4.5 mg/kg per d) that is cleared daily from plasma.
TL;DR: The toxic and therapeutic effects of AmB in clinical situations are contingent on competitive interactions between sterol-containing cellular membranes of the host and the parasite and components of blood, such as lipoproteins and proteins.
Abstract: Amphotericin B (AmB) binds to the cholesterol in lipoproteins, as determined by comigration in density gradient ultracentrifugation and changes in the circular dichroic spectrum. The saturation curve and Scatchard plots obtained with circular dichroism suggest that four to 10 cholesterol molecules in low-density lipoproteins bind to one molecule of AmB. AmB interacts more rapidly with low- and very-low-density lipoproteins than with high-density lipoproteins, but the circular dichroic spectrum of the complexed species is the same in all three cases. AmB also binds to other proteins in blood, but much higher concentrations of these proteins than of lipoproteins are needed for comparable binding. Interaction with lipoproteins stabilizes the antifungal activity of AmB. Interaction with lipoproteins and with much higher concentrations of other proteins in blood can also inhibit the effects of AmB on red blood cells, which contain cholesterol in their plasma membranes, but not the effects on Candida albicans, whose membranes contain ergosterol. An appropriate inference is that, when used clinically, AmB circulates in blood bound to lipoproteins and other proteins. The toxic and therapeutic effects of AmB in clinical situations are thus contingent on competitive interactions between sterol-containing cellular membranes of the host and the parasite and components of blood, such as lipoproteins and proteins.
01 Jan 1984
TL;DR: When a biologically imcompatible material is in contact with blood, there takes place thrombus formation on it via a rapid adsorption of plasma proteins and the subsequent adhesion of platelets.
Abstract: When a biologically imcompatible material is in contact with blood, there takes place thrombus formation on it via a rapid adsorption of plasma proteins and the subsequent adhesion of platelets. Numerous approaches to supress the adhesion of blood components onto synthetic surfaces have been studied and hydrogels are found to be useful.
TL;DR: The results indicate that increased free fatty acid concentrations in the maternal blood at the time of birth result in partial displacement of VPA from maternal binding sites, additional placental transfer, and thus fetal accumulation of the drug.
TL;DR: In this paper, a tracer-kinetic model is used to analyze in vivo initial extraction data on BBB transport of protein-bound steroid hormones (dihydrotestosterone, testosterone, estradiol, and corticosterone), thyroid hormones (triiodothyronine), and lipophilic amine drugs (propranolol).
Abstract: Previous studies have shown that the fraction of hormone or drug that is plasma protein bound is readily available for transport through the brain endothelial wall, i.e., the blood-brain barrier (BBB). To test whether these observations are reconcilable with the free-hormone hypothesis, a tracer-kinetic model is used in the present investigations to analyze in vivo initial extraction data on BBB transport of protein-bound steroid hormones (dihydrotestosterone, testosterone, estradiol, and corticosterone), thyroid hormones (triiodothyronine), and lipophilic amine drugs (propranolol). The plasma proteins used are bovine albumin and human orosomucoid. Transport data was fit to a modification of the Kety-Renkin-Crone equation of capillary physiology; the modified equation incorporates the principles of both capillary physiology and plasma protein-ligand mass action binding relationships. In most cases, the experimental data is best fit to the model equation when the apparent in vivo dissociation constant, KDa, of the ligand protein binding reaction increases to values that are 5- to 50-fold greater than the in vitro dissociation constant, KD. This result indicates that the rate of ligand dissociation from the plasma protein is accelerated in the capillary bed relative to the in vitro situation. It is hypothesized that the major factor leading to the rapid transport in vivo of protein-bound ligands into tissues such as brain is an endothelial-induced decrease in the affinity of the plasma protein for the ligand. Under these conditions, the amount of plasma ligand available for tissue clearance in vivo parallels the protein-bound fraction, not the free hormone.
TL;DR: Results indicate that serum albumin may act synergistically with other factors in the serum, such as transferrin, to limit iron supply and in this way restrict the growth of invading microorganisms.
Abstract: The effect of serum and serum proteins on enterobactin- and aerobactin-mediated utilization of transferrin iron has been investigated. Serum was found to impede transfer of iron from iron transferrin to enterobactin and from [55Fe]ferric enterobactin to cells of Escherichia coli BN3040 Na 1R iuc . In contrast, serum had essentially no effect on the rate of these reactions mediated by aerobactin. Three purified serum proteins, human serum albumin, bovine serum albumin, and human immunoglobulin, were comparable to human serum in their selective ability to interfere with the transfer of 55Fe from [55Fe]ferric enterobactin to E. coli BN3040 Na 1R iuc . The inhibitory effect of human serum albumin on the enterobactin-mediated transfer of iron from [55Fe]transferrin was enhanced by preincubation of the protein with the siderophore. Pretreatment of the bacterial cells with human serum albumin did not affect the rate of utilization of siderophore iron. A linear, reciprocal relationship was found to hold for human albumin concentration vs. the first-order rate constant ( kobsd ) for the velocity of iron transfer from iron transferrin to enterobactin. Binding of serum albumin to enterobactin increased the intensity of the near-ultraviolet absorption band of the siderophore and shifted it to longer wavelengths. The stoichiometry of binding to human and bovine serum albumins was established as 1:1, and the binding constant for both enterobactin and ferric enterobactin was estimated to be in the range 1 X 10(4)-1.2 X 10(5) M-1. These results indicate that serum albumin may act synergistically with other factors in the serum, such as transferrin, to limit iron supply and in this way restrict the growth of invading microorganisms.
TL;DR: In the depletion experiments increased endothelial permeability to ferritin coincided with loss of adsorbed albumin and IgG from the glycocalyx, suggesting that the adsorption of CP to the endothelial glycocalyX renders the underlying endothelium less permeable toFerritin.
Abstract: To examine directly the interaction of circulating proteins (CP) with the glycocalyx of pulmonary endothelium and its effect on endothelial permeability, two types of experiments were carried out. In the first, rats were exchange transfused with graded amounts of FC-43 fluorocarbon emulsion (FCE) resulting in CP concentrations of 25, 10, and 4 mg/ml, respectively. In the second, rats were exchange transfused with FCE to remove 99.9% of CP. The rats were then exchange transfused with 1 ml FCE containing 60 mg/ml of rat serum protein and killed 3.5, 7.5, and 15 min after the administration of protein. In all animals the distribution of albumin and immunoglobulin G (IgG) was visualized by immunocytochemistry, and endothelial permeability to native ferritin was measured by morphometry. In the depletion experiments increased endothelial permeability to ferritin coincided with loss of adsorbed albumin and IgG from the glycocalyx. Conversely, the presence of administered serum proteins in the glycocalyx and in a few luminal vesicles was associated with an endothelial permeability to ferritin indistinguishable from that of controls. These observations suggest that the adsorption of CP to the endothelial glycocalyx renders the underlying endothelium less permeable to ferritin.
TL;DR: All of the methods tested for viral inactivation markedly altered certain serum proteins, making these methods unsuitable for samples that are to be tested for certain enzyme levels and coagulation factors.
Abstract: Clinical specimens from patients infected with Lassa, Ebola, or Marburg virus may present a serious biohazard to laboratory workers. We have examined the effects of heat, alteration of pH, and gamma radiation on these viruses in human blood and on the electrolytes, enzymes, and coagulation factors measured in laboratory tests that are important in the care of an infected patient. Heating serum at 60 degrees C for 1 h reduced high titers of these viruses to noninfectious levels without altering the serum levels of glucose, blood urea nitrogen, and electrolytes. Dilution of blood in 3% acetic acid, diluent for a leukocyte count, inactivated all of these viruses. All of the methods tested for viral inactivation markedly altered certain serum proteins, making these methods unsuitable for samples that are to be tested for certain enzyme levels and coagulation factors.
TL;DR: Evaluation of the chromatographic profile of native baboon plasma suggested a marked increase in [125I]Sm-C binding to plasma proteins after in vivo pharmacological E2 treatment, which supports the concept that estrogen may play a role in the physiological increase in plasma concentrations of Sm-C associated with normal puberty.
Abstract: To evaluate the effects of physiological concentrations of estrogen on plasma concentrations of somatomedin-C (Sm-C) and GH, 16 chronic castrate female baboons were implanted either with blank Silastic capsules (n = 5) or capsules containing crystalline estradiol (E2; n = 11), which remained in place for 7 days. By day 7, serum E2 levels in treated animals rose into the physiological adult female range (mean +/- SEM, 96 +/- 9.2 pg/ml) and were greater (P less than 0.0005) than those in control animals (27.5 +/- 3.4 pg/ml). Sm-C concentrations rose significantly by day 7 in treated animals compared to those in control animals, whether assayed from unprocessed plasma (96% increase; P less than 0.01), plasma pretreated with glycine-HCl (99% increase; P less than 0.01), or plasma extracted with acid-ethanol (72% increase; P less than 0.02). GH concentrations in these animals were low and were not significantly different in E2-treated and control animals. To evaluate the effects of pharmacological doses of E2 on Sm-C and GH concentrations, six intact adult female baboons were treated with six daily injections of 1 mg E2 benzoate in oil. Serum E2 rose to a mean level of 1669 +/- 320 pg/ml on day 7. The plasma Sm-C concentration by day 7 was significantly higher than the pretreatment value whether assayed in untreated plasma (4.3-fold increase; P less than 0.01), plasma pretreated with glycine-HCl (2-fold increase; P less than 0.01), or plasma extracted with acid-ethanol (1.7-fold increase; P less than 0.01). Mean serum GH concentrations rose significantly from 3.3 ng/ml on day 0 to 23.6 ng/ml by day 7 (P less than 0.02). Evaluation of the chromatographic profile of native baboon plasma suggested a marked increase in [125I]Sm-C binding to plasma proteins after in vivo pharmacological E2 treatment; a broad peak of [125I]Sm-C binding over a size range from that of albumin to gamma-globulin was found. These results indicate that estrogen treatment of castrate or intact female baboons with both physiological and pharmacological doses results in an increase in plasma Sm-C concentrations that, at least in pharmacological doses, are mediated through an increase in GH concentrations. Although pharmacological E2 treatment results in a stimulation of plasma proteins that bind Sm-C, the effects on plasma Sm-C concentrations were found after procedures that diminish interference from circulating binding proteins. These data support the concept that estrogen may play a role in the physiological increase in plasma concentrations of Sm-C associated with normal puberty.
TL;DR: The binding of metal ions from salts and from corrosion products of 316 LVM stainless steel and MP-35 to blood cells and serum proteins was studied in vitro to explain the dissemination of corrosion products from the site of the implant and subsequent systemic responses by some individuals.
Abstract: The binding of metal ions from salts and from corrosion products of 316 LVM stainless steel and MP-35 to blood cells and serum proteins was studied in vitro. In the first series of experiments, metal salts were added to whole blood and then the blood separated into red cells, white cells, and serum. Nickel from nickel chloride or corrosion products of stainless steel bound in very small quantities to blood cells. Cobalt from cobalt chloride bound to both red cells and white cells. Chromium from chromic chloride (Cr3+) bound to cells in very small quantities whereas chromium from potassium dichromate (Cr6+) and corrosion products showed very high to binding to red cells and some binding to white cells. In a second series of experiments the blood was separated into its components and then the metal salts were added and the binding pattern was identical. In a third series of experiments serum which had interacted with the metal salts or corrosion products was separated into its components by isoelectric focusing on polyacrylamide gels. Almost all of the metal, whatever the source, was detected in the albumin region of the gels indicating strong binding to albumin. These studies on the cell and protein binding of the metals help to explain the dissemination of corrosion products from the site of the implant and subsequent systemic responses by some individuals.
TL;DR: The noncollagenous proteins of bovine bone were characterized using two high-resolution gel electrophoretic techniques and Electroblotting analysis of EDTA and guanidine HCl extracted material failed to reveal any higher molecular weight immunologically reactive species.
Abstract: We have characterized the noncollagenous proteins of bovine bone using two high-resolution gel electrophoretic techniques. Proteins were extracted from bone tissue by extended dialysis against 0.5 M EDTA. In some cases, a preextraction was done in guanidine HCl. Bovine plasma was also examined to identify the proteins in bone that might also be present in blood. We have scored 160 major, reproducible spots on our standard preparation bone map. These comprise about 40 individual protein groups. There are many more minor spots present which puts the total number present over 200. Of these groups, 15 are not present on plasma maps. Bone proteins identified in this way include actin, bone Gla-protein, and osteonectin. The remainder are unknown. Bone Gla-protein is present in bovine bone in four isoelectric forms, pI = 3.95-4.50. Electroblotting analysis of EDTA and guanidine HCl extracted material failed to reveal any higher molecular weight immunologically reactive species. The plasma proteins found in bone include, but are not limited to albumin, apo A-I lipoprotein, IgG, IgM, transferrin, alpha-2-HS-glycoprotein, and hemoglobin. Extraction with guanidine HCl plus EDTA significantly enriches the yield for the nonplasma proteins but does not appear to extract any additional bone proteins.
TL;DR: An investigation into blood-borne organometallic compounds that arise from the corrosion of metals used in orthopedic prosthetic devices was conducted using an in vivo rat model and an in vitro human serum model using 316LSS and HS-21.
Abstract: An investigation into blood-borne organometallic compounds that arise from the corrosion of metals used in orthopedic prosthetic devices was conducted using an in vivo rat model with an implantation time of 10 days and an in vitro human serum model with an incubation time of 5 days. Both models involved 316LSS and HS-21 in the spherical powder form of 55 +/- 5 microns microns in diameter at three different surface areas to body weight ratios. Gel chromatography on cross-linked dextran (G-200) was used to fractionate the serum proteins which bound the metal ions (chromium, cobalt, and nickel) released and identify them. Atomic absorption-spectrophotometry analysis measured the concentration of the metal ions in each serum protein peak as well as whole serum from both models, and red cell and tissue from the in vivo model. Within the serum proteins, the metal ions were bound to two of the principal serum protein peaks. Similar distributions of the metals among the serum protein peaks were not noted.
TL;DR: Results suggest that polymyxin B and antimicrobial proteins derived from polymorphonuclear leukocyte granules interact with lipid A in an analogous manner.
Abstract: Granule extracts from human polymorphonuclear leukocytes were prepared and fractionated by chromatography on Sephadex G75-SF. One fraction exhibited potent antimicrobial activity against an Rd1 lipopolysaccharide (LPS) mutant of Salmonella typhimurium. Susceptibility of the mutant to antimicrobial activity appeared to be due to binding of granule proteins to lipid A because isolated native LPS succeeded in blocking the antimicrobial activity of granule extracts whereas base-hydrolyzed LPS failed to do so. Centrifugation of control and base-hydrolyzed LPS-protein mixtures in cesium chloride gradients suggested that only control LPS formed complexes with antimicrobial proteins. Further evidence that bactericidal proteins from polymorphonuclear leukocyte granules interact with lipid A was that sublethal concentrations of polymyxin B (an antibiotic known to bind to lipid A) rendered target bacteria phenotypically resistant to granule proteins. Moreover, a mutant of S. typhimurium which synthesized a lipid A with decreased electronegativity due to increased 4-amino-4-deoxy-L-arabinosylation at the 4'-phosphate exhibited increased resistance to both polymyxin B and granule proteins. These results suggest that polymyxin B and antimicrobial proteins derived from polymorphonuclear leukocyte granules interact with lipid A in an analogous manner.
TL;DR: The results obtained indicate that the main denominator of specific gravity of edematous white matter is water content and that this relationship is not significantly altered by variations of blood volume or serum protein content.
Abstract: Vasogenic brain edema was induced in cats by cold injury (six animals), brain tumors (five animals), and brain abscesses (six animals). Water and electrolyte content, specific gravity, blood volume, and the amount of extravasated serum proteins were determined in small tissue samples taken from gray and white matter at various distances from the lesion. Edema was strictly confined to the white matter of the affected hemisphere and declined from the lesion to the more peripheral regions. It was characterized by the extravasation of serum proteins and an increase of water and sodium content with little or unpredictable changes of potassium and blood volume. The calculated sodium content of edema fluid varied between 129 and 135 μeq/ml, and serum protein content between 8.1 and 11.9 mg/ml. In all three types of edema, specific gravity and water content correlated closely with the same slope and intercept of the calculated regression (y=1.119–0.0011x,r=−0.91). The results obtained indicate that the main denominator of specific gravity of edematous white matter is water content and that this relationship is not significantly altered by variations of blood volume or serum protein content.
TL;DR: In this paper, it was shown that increased permeability of the glomerular capillary to plasma proteins is caused by increased synthesis of the protein moiety, which leads to the other characteristics of the nephrotic syndrome.
TL;DR: Plasma profoundly inhibited urate crystal-induced neutrophil luminol-dependent chemiluminescence (CL), and apo B lipoproteins were shown to be the inhibitory species in plasma.
Abstract: The inflammatory response to intraarticular urate crystals is known to be variable in gouty arthritis. One source of variability may be the modulation of cellular responses by crystal-bound proteins. We have identified three apolipoproteins among the polypeptides bound to urate crystals exposed to plasma. Identification was first based on their coelectrophoresis with polypeptides from isolated lipoproteins and diminution in the protein coat of crystals exposed to lipoprotein-depleted plasma. The apoproteins were immunochemically identified by the Western blotting technique as apoprotein A-I, apoprotein B (apo B), and apoprotein E. Because neutrophils play a central role in acute gout, we investigated the potential effects of lipoproteins on neutrophil-urate crystal interactions. Plasma profoundly inhibited urate crystal-induced neutrophil luminol-dependent chemiluminescence (CL). Lipoprotein depletion by KBr density gradient centrifugation completely abrogated the inhibitory effect of plasma on urate-induced CL. The inhibitory activity of lipoprotein-depleted plasma was restored by adding back the d less than or equal to 1.25 g/cm3 lipoprotein fraction. Plasma also inhibited urate crystal-induced neutrophil superoxide generation and cytolysis (lactic dehydrogenase loss). This inhibition was significantly diminished by lipoprotein depletion, indicating that the lipoprotein effect was not limited to CL. Lipoprotein-depleted plasma reconstituted with very low, intermediate, and low density lipoproteins (LDL) inhibited crystal-induced CL. High density lipoprotein reconstitution was without effect. Immunodepletion from plasma of all apo B lipoproteins by agarose-bound apo B-specific antibody also removed all inhibitory activity for urate-induced CL. Thus, apo B lipoproteins were shown to be the inhibitory species in plasma. Binding of apo B lipoproteins to urate crystals and inhibition of CL was also seen in the absence of other plasma proteins. In addition, the binding of whole lipoprotein particles to the crystals was verified by detection of crystal-associated cholesterol in addition to the apoprotein. The effects of LDL on urate crystal-induced CL were stimulus specific. Coincubation of urate crystals and neutrophils in the presence of 10 micrograms/ml LDL resulted in 83% inhibition. In contrast, CL responses to a chemotactic hexapeptide, opsonized zymosan, and Staphylococcus aureus were not inhibited by LDL. The effects of depletion of apo B lipoproteins on plasma suppression of urate crystal-induced CL appeared to be unique. Plasma or sera depleted of other urate crystal-binding proteins including fibrinogen, fibronectin, C1q, and IgG retained virtually all their CL inhibitory activity. Lipoproteins containing apo B are thus a major regulator of neutrophil responses to urate crystals. These lipoproteins are present in variable concentration in synovial fluid and may exert an important influence on the course of gout.
TL;DR: The studies show the feasibility of using specific antibody to lower the blood background just minutes prior to tumor imaging procedures using radiolabeled proteins.
Abstract: A major problem that arises when radiolabeled serum proteins are used for tumor imaging is the presence of a large amount of circulating background activity that persists for several days This delays imaging for at least 2 days following injection and necessitates computer subtraction of simulated background (second radiopharmaceutical injection) which introduces artifacts that are difficult to control We propose here the injection of specific antibody immediately before imaging as an alternate way of reducing blood background through clearance of the immune complex by the liver
111In-alkyl human transferrin and IgG were injected IV in BALB/c tumor mice, and followed in 18 h by anti-human transferrin and anti-human IgG antibody IV Two hours later, the tumor and organ distribution of activity was compared with control mice not receiving antibody 111In-transferrin blood activity was reduced to 1/48 of control with no decrease in tumor concentration: as a result, the tumor to blood ratio increased from 14:1 to 78:1 111In-IgG blood activity was reduced to 1/17 of control, again with no decrease in tumor The tumor to blood ratios increased from 07:1 to 17:1 The liver picked up most of the blood activity with none of the complex going to spleen, bone marrow, or kidney Dog experiments showed clearance of blood was 90% complete in less than 15 min following antibody injection Simultaneous scintillation images showed complete clearance of activity from the heart and great vessels in the chest and neck, and over the abdomen, with a concomitant increase in liver activity but no increase in spleen, kidney, or bone marrow activity These studies show the feasibility of using specific antibody to lower the blood background just minutes prior to tumor imaging procedures using radiolabeled proteins