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[Mechanical donor plasmapheresis using the Haemonetics Ultralite plasma collection system. 1. Collection of fresh plasma].

In a clinical study altogether 449 machine donor plasmapheresis for collection of platelet poor fresh plasma were carried out using the new developed Haemonetics-Ultralite-Plasma-Collection-System. The average time of donation for 600 g of plasma amounted to 36 min. In comparison to other automated plasmapheresis-systems an effective plasma flow is recorded for the Ultralite-machine. All plasmapheresis procedures were well tolerated by the donors. The collected plasma is equivalent to the requirements for fresh frozen plasma. Complications due to the device or donors are small with 2.9% of the performed procedures.

Blood Donors↗

Effects of changes in plasma hepatic-portal and systemic osmolality on plasma concentrations of arginine vasopressin in conscious newborn calves.

Systemic plasma concentrations of arginine vasopressin (AVP) were studied in three groups of 10-15 day-old conscious newborn calves. Animals in the first group (control group) and in the second group (systemic-hypertonic-injected group) received respectively isotonic and hypertonic (8 mmol NaCl/kg body weight) saline injection into the right jugular vein. Animals in the third group were fitted with chronic mesenteric and hepatic-portal catheters and received a 1 h-hypertonic saline infusion (2 mmol NaCl/kg body weight) into the main mesenteric vein. In animals in the second group there were parallel increases in systemic plasma concentration of Na+ (from 148.0 +/- 2.6 to 177 +/- 8 mmol/l; P less than 0.01), osmolality (from 289 +/- 2 to 319 +/- 4 mOsmol/kg H2O; P less than 0.01) and systemic plasma concentrations of AVP (from 4.2 +/- 0.4 to 11.1 +/- 0.6 pmol/l; P less than 0.01) 10 min after the injection. There were no significant changes in control animals. Hypertonic saline infusion into the main mesenteric vein in the third group induced an increase in concentration of Na+ (from 147.3 +/- 2.0 to 165.0 +/- 5.0 mmol/l; P less than 0.01) and osmolality (from 288 +/- 5 to 315 +/- 10 mOsmol/kg H2O; P less than 0.01) in hepatic-portal vein plasma but did not alter systemic plasma osmolality or concentrations of Na+ and AVP. This study demonstrates that the relationship between plasma concentrations of AVP and systemic osmolality is operative in the newborn calf but does not support the hypothesis that hepatic portal osmo-receptors sensitive to hyperosmolality influence AVP release.

Animals↗

Plasma lipoprotein metabolism in lean and in fat chickens produced by divergent selection for plasma very low density lipoprotein concentration.

Plasma lipoprotein metabolism was studied in vivo in two lines of chickens produced by selection for high and low plasma very low density lipoprotein (VLDL) concentration. Rates of VLDL secretion were measured by determining the rate of accumulation of triglyceride in the plasma after intravenous injection of anti-lipoprotein lipase antibody. The clearance of VLDL-triglyceride and its uptake into liver and adipose tissue was examined using radioactively labeled VLDL synthesized in vivo. The rate of VLDL secretion was about threefold higher in the high-VLDL line as compared to the leaner, low VLDL-line (6.7 vs 2.1 mumol VLDL triglyceride/h per ml of plasma). The clearance of VLDL from the circulation of the low VLDL line was much faster than that of the high VLDL line (t1/2 of 3.7 and 13.6 min, respectively). The proportion of administered radiolabel taken up by the abdominal fat pad was substantially greater in the fat line than in the lean line (11.9 vs 4.8%, respectively). Lipoprotein lipase activities in leg muscle and heart were consistently greater in the low-VLDL line and beta-hydroxybutyrate concentrations in the plasma of the low-VLDL line were significantly greater than those in the high-VLDL line (0.86 vs 0.48 mumol/ml). The results show that the approximately tenfold difference in plasma VLDL concentration between lines is primarily due to markedly different rates of hepatic VLDL production and that selection has made a major effect on partitioning of VLDL triglyceride between adipose and other tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

Chronobiologic dynamics of delta 5-3 beta-hydroxysteroids and glucocorticoids in rat brain and plasma and human plasma.

While a different timing of circadian rhythms does not necessarily demonstrate the operation of independent mechanisms, it is one step in the isolation of separate interacting rhythmic factors underlying the dynamics of all life. With this step in mind, circadian rhythms are quantified in rat plasma and brain for corticosterone (B), pregnenolone (P), and dehydroepiandrosterone (D) by the rejection of the zero-amplitude assumption with the single cosinor method, from data obtained every 3 hr for 24 hr on groups of three male Sprague-Dawley rats, 11-12 weeks of age. The rats were killed; steroids were extracted from brain and plasma and were radioimmunoassayed. In relation to the acrophase (phi) of B, the phi of P in brain (P = 0.035) and of D in plasma (P = 0.0012) preceded the phi of B. By contrast, in clinically healthy women, the phi of plasma dehydroepiandrosterone sulfate (DHEA-S) lags behind that of cortisol (F), on the average by 6 hr 28 min. Such a lag is also seen in men. A species difference in the time relations of delta 5-3 beta-hydroxysteroids vs. glucocorticoids in plasma is obvious (P less than 0.01). A difference in time relations of human circulating D, DHEA-S, and F between schizophrenic and clinically healthy men renders the time relations of glucocorticosteroids and delta 5-3 beta-hydroxysteroids in brain particularly interesting, as do relations of an egocentric and expansive personality to the rhythm characteristics of DHEA-S. The fact that the acrophases for some of the steroids investigated in brain and plasma, respectively, are differently timed is in keeping with the assumption that they involve partly different mechanisms, even if differences in the metabolic handling of different steroids also remain to be investigated.

Animals↗

Decrease in plasma high-density lipoprotein cholesterol levels at puberty in boys with delayed adolescence. Correlation with plasma testosterone levels.

A three-phase study tested the hypothesis that the decrease in the high-density lipoprotein cholesterol (HDL-C) level observed in boys at puberty is related to an increase in the plasma testosterone concentration. In phase I, 57 boys aged 10 to 17 years were categorized into four pubertal stages based on clinical parameters and plasma testosterone levels. These four groups showed increasing plasma testosterone values and decreasing HDL-C levels. In phase II, 14 boys with delayed adolescence were treated with testosterone enanthate (100, 200, and 200 mg/mo, respectively, for three months). Plasma testosterone levels during therapy were in the adult male range. Levels of HDL-C decreased by a mean of 7.4 mg/dL (0.20 mmol/L) and 13.7 mg/dL (0.35 mmol/L), respectively, after the first two doses. In phase III, 13 boys with delayed adolescence demonstrated increasing plasma testosterone levels and decreasing HDL-C levels (-12.0 mg/dL [-0.30 mmol/L]) during spontaneous puberty. Levels of HDL-C and apolipoprotein A-1 were correlated during induced and spontaneous puberty. Testosterone should be considered a significant determinant (not necessarily directly causal) of plasma HDL-C levels during pubertal development.

Adolescent↗

Detection of hepatitis B surface antigen in potentially contaminated human plasma and plasma fractions.

A new method is described for the quantitative detection of HBsAg in whole human plasma and in plasma fractions. The nonantigen proteins are digested with pepsin at low pH, and the antigen is precipitated with PEG. With use of only 20 ml of contaminated plasma, as few as 5.0 x 10(6) HBsAg particles/ml can be detected--a 40-fold increase in the apparent level of sensitivity of the Ausria II RIA (2.0 x 10(8) particles/ml). With 500 500 ml or more of plasma or plasma fractions, fewer than 5.0 x 10(5) particles/ml can be assayed--a 400-fold increase in RIA sensitivity and 1/10 the antigen concentration found in sera that proved infective when injected into chimpanzees. The pepsin-PEG method was used to quantitate the particles per milliliter in four equivocal RIA samples from the NIH Bureau of Biologics, three of which were definitely shown to contain antigen. The method has also been employed to detect fewer than 2.0 x 1010(8) particles/ml of HBsAg in deliberately contaminated high purity AHF concentrates and may be useful for monitoring plasma fractions prepared on a large scale or for detecting the antigen in equivocal samples from blood banks.

Blood Donors↗

Detection and quantitation of cleaved and uncleaved high molecular weight kininogen in plasma by ligand blotting with radiolabeled plasma prekallikrein or factor XI.

A method for the quantitative assay of native single chain and kallikrein cleaved two-chain high molecular weight (HMW)-kininogen in plasma is described. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole plasma is followed by electrotransfer of the electropherogram to nitrocellulose membranes and detection of the blotted HMW-kininogen with its physiologic ligands, radiolabeled plasma prekallikrein or radiolabeled factor XI. Using unreduced SDS-PAGE cleaved two-chain HMW-kininogen (Mr approximately 107,000 and 95,000), is electrophoretically separated from uncleaved single chain HMW-kininogen (Mr approximately 150,000). Counting the radioactivity of the nitrocellulose pieces corresponding to cleaved HMW-kininogen permits its quantitative measurement by comparison with standards consisting of decreasing amounts of fully dextran sulfate activated normal human plasma. Single chain HMW-kininogen is similarly assayed using reduced SDS-PAGE and unactivated normal human plasma standards. This technique is highly specific and sensitive to about 50 ng of either cleaved or uncleaved HMW-kininogen. Varying amounts of cleaved HMW-kininogen were found in a small series of plasmas from patients suffering from various inflammatory conditions. Higher levels of in vivo cleaved HMW-kininogen were observed during acute attacks of hereditary angioedema due to Cl-inhibitor deficiency. This technique may be useful for the assessment of the degree of in vitro or in vivo activation of the contact system.

Angioedema↗

[Vitamin C concentrations in maternal plasma, amniotic fluid, umbilical cord blood, the plasma of newborn infants, colostrum and transitory and mature breast milk].

Vitamin C concentrations have been measured in the plasma of 200 mothers and their newborns as well as in amniotic fluid and breastmilk. Out of this group 19 mother-infant-pairs were taken as normal control group with no risk factors, complications or diseases during pregnancy or delivery or in the newborn infant. Vitamin C concentrations in plasma showed great variability. This is true for both the entire study group and the normal control group. A positive correlation was found between the vitamin C concentrations in maternal plasma at the time of admission to the obstetric unit and that in the second stage of labor immediately before delivery. Cord blood and newborn plasma vitamin C concentrations were nearly twice as high compared to maternal concentrations. They too correlate with the concentrations in the maternal plasma. A further correlation was found between maternal plasma and amniotic fluid at the time of delivery (ratio about 1:3). No more significant correlations of vitamin C concentrations have been found in the normal control group. Various diseases or risk factors in mother and/or child were shown to be associated with lower vitamin C concentrations. Vitamin C concentrations were considerably lower in all biological fluids in smokers and mothers with diabetes. Other statistical correlations will be shown and possible casualties will be discussed. In this study vitamin C concentrations in groups with abnormal states are documented only with small numbers of cases and are therefore considered as a basis for further more specific investigations.

Adolescent↗

Plasma zinc levels in diabetes mellitus: relation to plasma albumin and amino acids.

Fasting plasma zinc levels were determined in 45 IDDM and in 40 NIDDM patients. Mean values were similar in both groups, but diabetic men showed a significantly higher plasma zinc (p less than 0.05) than diabetic women. In patients with diabetic nephropathy a lower zinc level was associated with decreased plasma albumin as compared to patients without complications (p less than 0.001). Neuropathy and macro-angiopathy were also associated with lower zincemia (p less than 0.05) but in the presence of normal albumin levels. In IDDM without nephropathy a significant positive correlation was found between plasma zinc and plasma glucose, albumin, branched chain amino acids and glutamine, while in NIDDM without nephropathy a significant positive correlation exists between plasma zinc and the amino acids glutamine, valine, histidine and lysine.

Amino Acids↗

Inhibition of tissue factor/factor VIIa activity in plasma requires factor X and an additional plasma component.

A study was carried out to explore requirements for the inhibition of tissue factor-factor VIIa enzymatic activity in plasma. Reaction mixtures contained plasma, 3H-factor IX or 3H-factor X, tissue factor (vol/vol 2.4% to 24%), and calcium. Tissue factor-factor VIIa activity was evaluated from progress curves of activation of factor IX or factor X, plotted from tritiated activation peptide release data. With normal plasma, progress curves exhibited initial limited activation followed by a plateau indicative of loss of tissue factor-factor VIIa activity. With hereditary factor X-deficient plasma treated with factor X antibodies, progress curves revealed full factor IX activation. Adding only 0.4 micrograms/mL factor X (final concentration) could restore inhibition. Inhibition was not observed in purified systems containing 6% to 24% tissue factor, factor VII, 0.5 micrograms/mL, factor IX, 13 micrograms/mL, and factor X up to 0.8 micrograms/mL, but could be induced by adding barium-absorbed plasma to the reaction mixture. Thus, both factor X and an additional material in plasma were required for inhibition. The amount of factor X needed appeared related to the concentration of tissue factor; adding more tissue factor at the plateau of a progress curve induced further activation. These results also indicate that inhibited reaction mixtures contained active free factor VII(a). Preliminary data suggest that inhibition may stem from loss of activity of the tissue factor component of the tissue factor-factor VII(a) complex.

Barium↗

Plasma volume and estimated liver plasma flow during hyperbaric and hyperoxic exposures in awake dogs.

Five different experiments were conducted to determine if estimated liver plasma flow and/or plasma volume were changed as a result of exposure to 2.8 atmospheres absolute (ATA) while breathing 100% oxygen or 6 ATA while breathing compressed air. The experiments were designed to separate the relative roles of the ambient pressure, the partial pressure of oxygen, the time of high oxygen exposure or some combination of these factors on any observed changes. We found that time was not a factor in the changes seen. Hyperbaria resulted in a decrease in estimated liver plasma flow at all pressures greater than 1 ATA. There was an apparent increase in plasma volume at 1.3 ATA and a return towards 1 ATA values at higher pressures. Hyperoxia resulted in a decrease in estimated liver plasma flow at 975 mm Hg but not at 912 mm Hg. The flow was then increased again at 2128 mm Hg. Plasma volume decreased significantly at 912 mm Hg returned to baseline (152 mm Hg) values at 975 mm Hg and then decreased again at 1054 and 2128 mm Hg PO2.

Animals↗

A laboratory model demonstrating osteocyte-osteoblast control of plasma calcium concentrations. Table model for plasma calcium control.

This report describes a laboratory model designed to illustrate a newer concept for the control of plasma calcium concentrations. This postulate suggests that plasma calcium levels are the result of a balance or imbalance in opposing calcium ion fluxes between plasma and bone fluid compartments existing around osteocyte-lining cells (osteoblasts) units in bone. The metabolic control of these fluxes is postulated to reside within the lining cells on the surface of bone. These cells serve as a cellular interface between the two fluid compartments. The model described in this report illustrates these principles by using the height of columns of water in cylinders to represent calcium ion concentrations. A water pump, representing the calcium transcellular transport system in the lining cells, maintains a higher level of water in the cylinder representing plasma than in that representing bone fluid. This is accomplished by continuous pumping of water from the bone fluid cylinder to the plasma cylinder. Water is returned to the bone fluid cylinder as long as a differential in the height of water in the two cylinders exists. A constant height of water in the plasma cylinder is maintained when the two fluxes are in equilibrium. A constant height of water in the cylinder representing bone fluid is maintained by the level of water in a much larger cylinder representing calcium equilibrium between the solid and liquid phases of bone. The primary hormone controlling the rate of calcium transfer from bone fluid to blood, or in the model regulating the speed of water pump, is parathyroid hormone.

Adult↗

Presence of a platelet aggregating factor in the plasma of patients with thrombotic thrombocytopenic purpura (TTP) and its inhibition by normal plasma.

Three patients with thrombotic thrombocytopenic purpura (TTP) were treated by infusion of normal plasma with dramatic responses. The plasmas collected from these patients during relapse induced in vitro aggregation of washed platelets from both normal donors and the patients during remission. The platelet aggregating factor was not dialyzable or adsorbable by Al(OH)3 and was not inactivated by diisopropylfluorophosphate, hirudin, or heparin in the presence of normal amounts of antithrombin. In contrast to the platelet aggregation induced by platelet isoantibody, the platelet aggregating activity of TTP plasma diminished as a function of time when it was incubated with normal plasma at 37 degrees C. These observations suggest that at least some instances of TTP appear to be due to deficiency of a plasma inhibitor to counteract a platelet aggregating factor demonstrated to be present in the plasma of these patients.

Adolescent↗

Proteolytic activities in plasma membrane preparations from rat liver. 1. Preparation of rat liver plasma membranes and solubilization of membrane bound proteases.

Plasma membranes (PM) were prepared by discontinuous density gradient centrifugation of crude nuclear fractions from 6 rat livers. These "nuclear" PM (PM-n) were 15-fold enriched in plasma membrane marker enzymes and contained an endopeptidase activity degrading azocasein at pH 7. To get larger amounts of plasma membranes, microsomal fractions obtained in large scale subcellular fractionations were subjected to continuous gradient zonal centrifugation. These "microsomal" PM (PM-m) were 22-fold enriched in 5'-nucleotidase, however, the separation of PM from endocellular membranes was not complete. PM-m showed endopeptidase activity degrading azocasein at pH 5.4 faster than at pH 7.5 and exopeptidases degrading Ala-Pro-pNA and Ala-pNA at pH 7.6. The latter two activities were distributed over the gradient similar to PM marker enzymes and can be solubilized by detergent and proteinase treatment. Therefore, dipeptidyl-aminopeptidase IV and Ala-aminopeptidase are intrinsic plasma membrane enzymes and can be used as additional markers for rat liver plasma membranes. The efficiency and selectivity to solubilize plasma membrane bound endopeptidase, DPP IV and aminopeptidase activities are compared.

Animals↗

Relationship among plasma iron, plasma iron turnover, and reticuloendothelial iron release.

A circadian rhythm was demonstrated in 10 males and 10 females with respective mean decreases in plasma iron concentration at 18 hr of 62% and 47% of morning values. Ferrokinetic studies performed on 5 normal males and 5 normal females showed a more rapid disappearance rate and lower plasma iron turnover in the evening. Parallel studies were done on 6 normal males in the morning and 4 normal males in the evening of the release of reticuloendothelial iron at 8 and 18 hr after intravenous injection of 59Fe chondroitin ferrous sulfate. The 6-hr release in the morning was 54.1% and in the evening 25.9%. Composite data from morning and evening showed a correlation between plasma iron level and plasma iron turnover (r = 0.76, p less than 0.001). A similar correlation existed between the plasma iron level and the percent of radioiron released from the reticuloendothelial system (r = 0.67, 0.02 less than p less than 0.05). These data are consistent with a fluctuating iron release from the reticuloendothelial cell in normal subjects, which would account for the diurnal variation in plasma iron.

Chondroitin Sulfates↗

Human placental (fetal) fibronectin: increased glycosylation and higher protease resistance than plasma fibronectin. Presence of polylactosamine glycopeptides and properties of a 44-kilodalton chymotryptic collagen-binding domain: difference from human plasma fibronectin.

Human placental fibronectin was isolated from fresh term placenta by urea extraction and purified by gelatin affinity chromatography. A 44-kDa chymotryptic fragment, also purified by gelatin affinity chromatography, gave a broad, diffuse band on polyacrylamide gel electrophoresis, whereas the analogous 43-kDa fragment from human plasma fibronectin migrated as a defined, narrow band. Upon extended treatment with endo-beta-galactosidase from Escherichia freundii, the 44-kDa chymotryptic gelatin-binding fragment from placental fibronectin changed its behavior on gel electrophoresis and migrated as a narrower, more defined band. The carbohydrates on human placental fibronectin contained a large percentage of polylactosamine structures, part of which occurred on the gelatin-binding fragment, comprising almost twice as much carbohydrate as plasma fibronectin. NH2-terminal amino acid sequence analysis of the chymotryptic gelatin-binding fragments from both fibronectins showed the first 21 residues to be identical. Tryptic and chymotryptic peptide maps of the gelatin-binding fragment from placental fibronectin, however, showed differences including several protease-resistant domains not found in the analogous fragment from plasma fibronectin. Intact placental fibronectin contains 20,000 Da of carbohydrate, whereas plasma fibronectin contains 11,000 Da. Placental fibronectin is more protease-resistant than plasma fibronectin, possibly due to the additional carbohydrate. Polyclonal antibodies against either fibronectin completely cross-react with amniotic fluid fibronectin, placental fibronectin, and plasma fibronectin upon Ouchterlony immunodiffusion. Human fibronectins of putatively the same polypeptide structure are, therefore, glycosylated in a dramatically different fashion, depending on the tissue of expression. If the patterns of glycosylation comprise the only difference in the glycoprotein, this may confer the characteristic protease resistance found for each of the fibronectins.

Chymotrypsin↗

1,25-Dihydroxyvitamin D3 injections into rat fetuses : effects on fetal plasma calcium, plasma phosphate and mineral content.

The in vivo effects of 1,25-(OH)2D3 were assessed using fetuses from normal and thyroparathyroidectomized (TPTX) pregnant rats. 21.5-day old decapitated fetuses from TPTX mothers exhibited lowered basal plasma calcium, elevated basal plasma phosphate and an increased percentage of total ash compared to intact littermates. In decapitated fetuses from normal mothers, neither plasma calcium nor plasma phosphate was changed. Subcutaneous injection of 1 micrograms of 1,25-(OH)2D3/kg of body weight to 19.5-day old fetuses (intact or deprived of their parathyroid glands by decapitation) from TPTX mothers induced a marked rise in plasma calcium levels (2.01 and 3.66 mg/dl, respectively) 48 h later. Little change occurred in fetuses from normal mothers (1.06 mg/dl in decapitated and no change in intacts). A decrease in plasma phosphate levels was observed with the same dose in both decapitated and intact fetuses from TPTX mothers (- 1.39 and - 0.65 mg/dl, respectively), while no modification was found in fetuses from normal females. Therefore, the hypersensitivity of fetuses from TPTX mothers to 1,25-(OH)2D3 was unrelated to the development of the fetal hyperparathyroidism secondary to maternal TPTX. The percentage of ash was unchanged in decapitated fetuses from TPTX mothers and was increased in intact littermates after 1,25-(OH)2D3 treatment. However, these values for total ash may represent alterations in bones and/or soft tissues.

Animals↗

Inhibition by bacitracin of rat adipocyte plasma membrane degradation of 125I-insulin is associated with an increase in plasma membrane bound insulin and a potentiation of glucose oxidation by adipocytes.

The present study demonstrated that at physiological concentrations of insulin bacitracin inhibited the degradation of specifically bound insulin by enzymes located in the rat adipocyte plasma membrane. Bacitracin increased the amount of intact insulin specifically bound to the plasma membrane and potentiated the stimulation of adipocyte glucose oxidation by submaximal concentrations of the hormone. In contrast to agents such as chloroquine, which inhibit lysosomal degradation of internalized insulin, bacitracin was shown by two approaches to inhibit a degradative process localized to the adipocyte plasma membrane. Cyanide and 2,4-dinitrophenol, agents which inhibit energy requiring endocytosis, had no effect on the bacitracin inhibition of cellular degradation of 125I-insulin. Bacitracin directly inhibited 125I-insulin degradation by isolated plasma membranes at similar concentrations and to a similar extent as found with cells. The degradative process inhibited by bacitracin accounted for the majority of cellular degradation of the hormone. The increased 125I-insulin bound to adipocytes was shown to be intact by gel chromatographic analysis and was localized to the plasma membrane by direct and indirect approaches. Bacitracin increased 125I-insulin specifically bound to isolated plasma membranes as early as 2 min. The 125I-insulin bound to adipocytes in the presence of bacitracin was completely dissociable by the addition of 8 microM unlabeled insulin whereas a significant portion of 125I-insulin bound to chloroquine-treated cells could not be dissociated. Bacitracin slowed dissociation of 125I-insulin from the cells. Bacitracin increased the 125I-insulin binding to cells in the presence and absence of cyanide and 2,4-dinitrophenol. Bacitracin potentiated the stimulation of adipocyte glucose oxidation at submaximal concentrations of insulin.

Adipose Tissue↗