Showing papers on "Blood proteins published in 1977"

Principles of albumin and IgG analyses in neurological disorders. I. Establishment of reference values.

Abstract: Protein parameters in CSF and serum have been studied in ninety-three reference subjects. CSF/S albumin ratio is proposed to be superior to CSF-protein or CSF-albumin as a test of the blood-brain barrier function, while IgG-index = (CSF/S IgG ratio)/(CSF/S albumin ratio) is superior to CSF IgG/protein ratio or CSF/albumin ratio for the demonstration of IgG elevation in CSF due to synthesis within CNS. The two quotients recommended correct for variations of albumin and IgG concentrations in serum. When the serum proteins are within reference range, the CSF protein concentrations are mainly regulated by the permeability of the blood-brain barrier, while the influence of S-albumin and S-IgG is only secondarily. The CSF/S albumin ratio is age dependent, while IgG-index is not. A proposed graphical presentation of CSF/S albumin and IgG-index may facilitate the interpretation of these parameters in routine clinical work.

High resolution two-dimensional electrophoresis of human plasma proteins

Abstract: The two-dimensional electrophoretic technique of O'Farrell has been adapted to the analysis of human plasma proteins, and 30 polypeptides have been identified in the pattern produced. Genetic variants involving charge (isoelectric point) or size (molecular weight in the presence of sodium dodecyl sulfate) changes should be routinely detectable in at least 20 proteins at once, facilitating studies of human mutation rates.

Pathogenesis of alcohol-induced accumulation of protein in the liver.

Abstract: Alcohol feeding to rats produced hepatomegaly, associated with enlargement of the hepatocytes. The increase in liver dry weight was accounted for not only by fat but also by protein accumulation, primarily in microsomes and cytosol, with a selective increase in export proteins: concentrations of both immunoreactive albumin and transferrin were augmented in liver microsomes and cytosol of ethanol-fed rats. To investigate the mechanism of this protein accumulation, [14C]leucine was injected intravenously and its incorporation into both liver and serum proteins was measured after various time intervals. Rates of synthesis and export were assessed from protein labeling and specific activities of leucyl-tRNA. Synthesis of liver protein and proalbumin were enhanced by chronic ethanol feeding, but this was not associated with a corresponding rise in serum albumin output. Actually, there was a significant retention of the label in liver albumin and transferrin with delayed appearance in the serum of ethanol-fed rats. This indicated that, regardless of the changes in synthesis, the export of protein from the liver into the plasma was impaired. This alteration in export was associated with a decreased amount of polymerized tubulin in the liver of ethanol-treated animals. Thus, both enhanced protein synthesis and defective export contribute to the ethanol-induced accumulation of liver protein, and the decrease in liver microtubules represents a possible site for impairment of protein export.

Improved medium for clonal growth of human diploid fibroblasts at low concentrations of serum protein.

Abstract: A new medium (MCDB 104) has been developed which will support clonal growth of WI-38 cells at concentrations of serum protein as low as 25 micrograms per ml (equivalent to 005% serum) The principal factors responsible for reduction of the protein requirement are: (a) adjustment of all nutrient concentrations in medium F12 to experimentally determined optimum values for WI-38 cells; (b) supplementation with trace elements; (c) replacement of hypoxanthine and folic acid with adenine and folinic acid; and (d) coating of the culture surface with polylysine Individually, many of these modifications exert only a small effect on cellular growth at reduced protein concentrations, but collectively their effect has been very substantial Other strains of fibroblast-like human diploid cells from amniotic fluid, fetal lung and newborn foreskin also will grow at reduced concentrations of serum protein in the new medium

Radioimmunoassay of human eosinophil cationic protein.

Abstract: A radioimmunosorbent assay has been developed which allows the detection in serum of a cationic protein derived from eosinophil granulocytes. In 34 healthy individuals the mean level was 31 microgram/1. with a range of 5-55 microgram/l. The serum concentration of 'eosinophil' cationic protein was correlated (p less than 0.001) to the number of eosinophil granulocytes in peripheral blood. Quantitation of 'eosinophil' cationic protein in serum might be useful in the study of eosinophil granulocyte turnover and function in vivo.

Principles of albumin and IgG analyses in neurological disorders. II. Relation of the concentration of the proteins in serum and cerebrospinal fluid.

Abstract: A total of 116 patients were subgrouped according to the presence of neurological disorder and abnormal S-albumin, S-IgG, S-haptoglobin and S-CRP. Abnormal serum protein concentrations were registe...

A non-chromatographic non-extraction radioimmunoassay for serum aldosterone.

Abstract: A direct radioimmunoassay for serum aldosterone was developed using a highly specific sntibody and 8-anilino-1-naphthalene sulfonic acid as a blocking agent to inhibit the binding of aldosterone to serum proteins. 125I-labeled aldosterone was used as the labeled antigen and polyethylene glycol was used to separate antibody-bound and free aldosterone. The minimum detectable concentration was 1.5 pg/tube. There were excellent correlations between the present method and other methods, i.e., 1) a method using tritiated aldosterone, 2) a method using dichloromethane extraction before assay, and 3) a commercial kit method. The intra-assay coefficient of variation was 6.9%, and the inter-assay coefficient of variation was 10.7%. The values found in normal human serum were comparable with those reported using other methods. The present radioimmunoassay eliminates both extraction of aldosterone from serum and chromatographic separation and requires only 0.1 ml of serum for assay.

Gingival Fluid and Serum in Periodontal Diseases: I. Quantitative Study of Immunoglobulins, Complement Components, and Other Plasma Proteins

Abstract: 1. Gingival fluid from severely inflamed periodontal tissue represents a 15 to 30% dilution of serum with respect to the proteins studied, with the exception of C3 and in some subjects, C4. 2. A marked decrease in C3 levels is found in most, if not all, gingival fluids, and a marked decrease of C4 levels is found in some gingival fluids. This suggests that complement might be activated during periodontal inflammation. 3. The concentrations of proteins in the gingival fluid are not related to their molecular weight.

Reactions of formed elements of blood with plasma proteins at interfaces

Abstract: We have seen from the preceding how complex the behavior of single proteins and their simple combinations can be. There is no way of studying the behavior of the same proteins in unmodified whole blood: all man-made surfaces, unlike the blood vessel wall, cause activation of clotting or adhesion of platelets and white blood cells. It is true that certain changes imposed upon a sample of blood by the walls of its artificial container can be prevented by additives, but then we are adding one artifact to another. In the carefully planned in vitro test systems where no anticoagulant is used, such as in brief exposure of a biomaterial-lined space to native blood,', or where blood is allowed to flow directly from blood vessel to material whatever is being measured must be some early effect of the triggered clotting process. In systems where anticoagulants are used, the effect of these additives is often unpredicted. Only quite recently the discovery was made that removal of calcium ions (e.g. by addition of citrate) promoted secondary aggregation of platelets,5 whereas the more reasonable explanation had been that it was inhibited by addition of heparin. The diversity in action of these two anticoagulants should not be surprising, since they inhibit clotting in quite different ways. For this reason, in experiments where they differ in action less from each other than from a third added variable, we can claim to be observing the effects of that third variable and not of anticoagulant. For example, we found that both in heparinized and in citrated plasma, activation by contact with glass or diatomaceous earth reduced the ability of plasma to modify its own deposit on a glass-like surface.6-R In this case we may presume that the anticoagulants did not affect this property of intact plasma. We may even presume that plasma, being intact in the body, also has this property in vivo. Similarly, under certain conditions platelet retention is affected more by the retaining material surface than by the anticoagulant used; !' again, this would give us hope that the same material will do in vivo without anticoagulant what it did in vitro with anticoagulants. Casting aside the effects of anticoagulants in the belief that we control them, and building on our knowledge of protein adsorption, we face the task of finding the few among thousands of plasma and platelet o r white cell membrane proteins involved in the various surface/ blood interactions. Fortunately,

Protein Binding of Antimicrobials: Clinical Pharmacokinetic and Therapeutic Implications

Abstract: Binding of antimicrobial agents to serum proteins, and to extravascular tissues, affects their distribution, elimination, and pharmacological activity The extent of binding of drugs to serum proteins is both drug concentration and protein concentration dependent However, changes in drug concentrations within therapeutic range have little effect Drug-protein binding may be reduced by the presence of other drugs, and also by endogenous substances The latter may be important in cases of impaired renal or hepatic function and in disease states associated with elevated free fatty acids The greatest reductions in protein binding are observed with drugs that are normally highly bound Equations are presented to describe the influence of the binding of drugs to serum proteins and tissues on the percentage of drug which is free in the body, the concentration of free and total drug in serum, and the apparent distribution volume of drug in the body Changes in the percentage bound to serum proteins tend to produce curvilinear changes in the various values with the greatest changes occurring with highly bound drugs (greater than 80% binding) Changes in the percentage bound to tissues tend to produce linear changes in all values except the apparent drug distribution volume Small changes in tissue binding of highly bound drugs cause marked changes in apparent distribution volumes Although tissue and extravascular fluid drug levels are primarily influenced by the free drug levels in serum, calculation of actual tissue levels is complicated by variable binding characteristics of specific tissues and tissue fluids, and also by the lipophilic nature of the drug Renal elimination of antimicrobial agents is markedly influenced by serum protein binding if the major elimination mechanism is glomerular filtration Serum protein binding has little effect on drug elimination in cases of elimination by renal tubular secretion and hepatic extraction As in the case of distribution, renal clearance and hepatic extraction may be a function of both protein binding and drug lipophilicity A drug which is bound to serum proteins has no antibacterial activity in vitro However, binding of drugs to serum proteins in vivo has major clinical significance only when levels of free drug are reduced to values below the minimum inhibitory concentrations of susceptible micro-organisms In many cases, high protein binding may be compensated for by greater intrinsic antimicrobial activity of lipophilic drugs

Plasma proteins present in human cortical bone: enrichment of the alpha2HS-glycoprotein.

Abstract: The spectrum of plasma proteins present in human cortical bone and permanent dentine has been determined. One plasma glycoprotein, theαHS-glycoprotein, was found to be present at a high concentration in both bone and dentine and was shown to be concentrated in the mineralized tissues with respect to the other plasma proteins by factors of between 30 and 100. In this respect theαHS-glycoprotein is analogous to the G2B-glycoprotein and α-glycoprotein of bovine and rabbit b one, respectively. The binding ofαHS-glycoprotein and albumin to calcium phosphates generated within serum samples has been studied at different serum: precipitate ratios. In each case all theαHS-glycoprotein was removed from the samples and theαHS-glycoprotein was concentrated with respect to albumin by factors ranging from 370 at the highest serum: precipitate ratio to 25 at the lowest ratio. The plasmaαHS-glycoprotein concentrations of patients with Paget's disease of bone were shown to be substantially lower than the normal range, with significant negative correlation between theαHS-glycoprotein concentration and the plasma alkaline phosphatase activity.

Plasma protein synthesis by isolated rat hepatocytes.

Abstract: A system of preparation of rat hepatocytes with extended viability has been developed to study the role of hormones and other plasma components upon secretory protein synthesis. Hepatocytes maintained in minimal essential medium reduced the levels of all amino acids in the medium except the slowly catabolized amino acids leucine, isoleucine, and valine, which steadily increase as the result of catabolism of liver protein. Although the liver cells catabolize 10-15% of their own protein during a 20-h incubation, the cells continue to secrete protein in a linear fashion throughout the period. The effects of insulin, cortisol, and epinephrine on general protein synthesis, and specifically on fibrinogen and albumin synthesis, have been tested on cells from both normal rats and adrenalectomized rats. Cells from normal animals show preinduction of tyrosine amino transferase (TAT), having at the time of isolation a high level of enzyme which shows only an increase of approximately 60% upon incubation with cortisol. In contrast, cells from adrenalectomized animals initially have a low level of enzyme which increases fourfold over a period of 9 h. The effects of both epinephrine and cortisol on protein synthesis are also much larger in cells from adrenalectomized animals. After a delay of several hours, cortisol increases fibrinogen synthesis sharply, so that at the end of the 20-h incubation, cells treated with hormone have secreted nearly 2.5 times as much fibrinogen as control cells. The effect is specific; cortisol stimulates neither albumin secretion nor intracellular protein synthesis. The combination of cortisol and epinephrine strongly depresses albumin synthesis in both types of cells. Insulin enhances albumin and general protein synthesis but has little effect on fibrinogen synthesis.

Biosynthesis of the third component of complement (C3) in vitro by monocytes from both normal and homozygous C3-deficient humans.

Abstract: Human monocytes synthesized the third component of complement (C3) up to 5 wk in vitro. Evidence for net C3 synthesis was based on (a) incorporation of 14C-labeled amino acids into C3 protein, (b) indentity of the allotype of C3 produced in vitro with that of the doner's serum C3, even in the presence of carrier C3 protein of a different allotype; (c) correspondence of electrophoretic mobility, size, and subunit structure of C3 protein produced in vitro with serum C3; (d) inhibition of C3 production with cycloheximide. Monocytes from two unrelated C3-deficient patients were studied under conditions that supported C3 synthesis by normal monocytes. Serum from each of the patients contained less than 1% of the normal C3 concentration, buth their monocytes produced C3 at approximately equal to 25% of the normal rate when studied after 2 wk in vitro. The C3 produced in vitro by monocytes from one of the patients had the molecular weight of normal serum C3 and dissociated appropriately under reducing conditions. Monocytes from C3-deficient patients could not be distinguished from normals on the basis of morphology, rosetting with C3-coated erythrocytes, or rates of C2, and total protein synthesis.

Studies of the Mechanism of the Human Platelet Release Reaction Induced by Immunologic Stimuli III. Relationship Between the Binding of Soluble IgG Aggregates to the Fc Receptor and Cell Response in the Presence and Absence of Plasma

Abstract: The release reaction of washed platelets to which 3H-BDB-IgG had been bound in the presence of HSA or BSA was also inhibited by the subsequent addition of plasma or plasma proteins (human IgG being more effective than bovine IgG, F(ab′)2, HSA, or BSA). 3H-BDB-IgG bound in the presence of either plasma or human IgG did not induce release when the platelets were subsequently suspended in media lacking these proteins. Thus, it appears that the platelet Fc receptor binds 3H-BDB-IgG by a process which is effectively inhibited by plasma, or by free IgG with an intact Fc, and to some extent by high concentrations of other proteins. The effects of bound IgG aggregates are dependent on the other proteins present both during binding and subsequently added. The mechanism of such receptor modulation and its implications in vivo are discussed.

Progressive changes in individual milk protein concentrations associated with high somatic cell counts.

Abstract: Progressive changes in the concentrations of milk protein components were followed after infusions of Streptococcus agalactiae or bacterial endotoxin into different quarters of individual cows. Both types of infusion produced similar increases in somatic cell count and resulted in similar changes in milk proteins, although the effects of the endotoxin infusion lasted for a shorter length of time. The treatments had little effect on α-lactalbumin and β-lactoglobin concentrations, but serum albumin and immunoglobulin (Ig) concentrations increased markedly. The greatest effect on serum albumin was after the endotoxin infusion and on Ig after the Str. agalactiae infusion. Changes in the individual globulins indicated that passive transfer of blood proteins to milk could not account for the observed increases in IgM and IgA. α s1 -Casein and β-casein concentrations were reduced and inversely related to somatic cell count during the immediate post-infusion period, and this was accompanied by an increase in para-κ-casein. Para-κ-casein was not detected in pre-infusion or post-recovery milk samples. The decrease in β-casein was greater than that of α s1 -casein. Casein concentrations returned to pre-infusion levels 2 d and 5 d after the endotoxin and Str. agalactiae infusions respectively. The possibility that proteolytic enzymes are partly responsible for the changes in casein concentration is discussed.

Pharmacokinetics of Fosfomycin

Abstract: Fosfomycin, an antibiotic discovered in Spain, has a unique chemical structure and pharmacologic features that are promising for clinical therapy. It is only partially absorbed orally, with relatively low blood levels. Intramuscularly, however, absorption is complete with peak blood levels 3-5 times as high as orally, and rapid intravenous injections give serum concentrations almost twice as high as intramuscularly. Some accumulation occurs with all three routes, and concentrations in excess of 1,000 mug/ml are consistently obtained in the urine with parenteral doses every 6 h. The serum half-life is 1.5-2 h, urinary excretion is by glomerular filtration, the antibiotic is not bound to serum proteins, and the volume of distribution is large. Diffusion into tissues and body fluids is good. Thus, the pharmacologic characteristics of fosfomycin along with its low toxicity make it comparable in these respects to other well-established antibiotics.

[Isolation and characterization of an unknown, leucine-rich 3.1-S-alpha2-glycoprotein from human serum (author's transl)].

Abstract: This article describes the isolation and characterization of a previously unknown, leucine-rich 3.1S-alpha2-glycoprotein from human serum. The starting material was Supernatant II, which is a byproduct in the large-scale preparation of albumin and gamma-globulin by the ethacridine lactate/ammonium sulfate procedure. The purified protein is homogenous both in carrier-free and molecular-sieve electrophoresis. Its electrophoretic mobility indicates that it belongs to the alpha2-globulins. Isoelectric focussing splits it into 4 bands with isoelectric points between 3.8 and 4.1. In the ultracentrifuge it sediments in a single band at 3.1S. The molecular weight determined by equilibrium sedimentation is 49 600 +/- 4 000. Subunits were not detected. Chemical analysis reveals it to be a glycoprotein with a carbohydrate content of 23%. The amino acid content is unusual in that the leucine content is almost 17%, i.e. about every fifth amino acid is a leucine. The average concentration of the leucine-rich 3.1S-alpha2-glycoprotein in human serum was determined by a quantitative immunological method as 2.1 mg per 100 ml. The protein is not related to any of the previously known well characterized serum proteins.

Isolation from human serum of an inactivator of bacterial lipopolysaccharide.

Abstract: By a series of chromatographic procedures involving precipitation by salt, gel filtration, anionic exchange, and hydroxyapatite elution, a protein--termed the lipopolysaccharide inactivator (LPS-I)--has been isolated from normal human serum. As a result of treatment of bacterial lipopolysaccharide (LPS) by LPS-I, the treated LPS loses its toxicity for mice and reactivity in the Limulus assay and appears to be irreversibly disaggregated. The inactivation of the LPS by the purified LPS-I is temperature and time dependent and is not blocked by the addition of irreversible inhibitors of serine esterases. The LPS inactivator migrates as an alpha-globulin in whole serum and has a sedimentation velocity of approximately 4.5S. Characteristics of the inactivated LPS are briefly described using internally labeled LPS.

New approach to evaluation of proteinuric states.

Abstract: We evaluated the use of immunonephelometric methods for measuring specific urinary proteins. Using a nephelometer to detect light scattering (angle, 31 degrees), we measured some proteins immunonephelometrically in serum and aliquots of 24-h urines from 50 apparently healthy children, ages 2-17 years. The mean urinary excretion rate (mg/24h) and the range of values was: for albumin 5.5 (range, 0-13.3), for transferrin 0.5 (0-1.9, for IgG 3.3 0-12), and for alpha 2-macroglobulin 0.6 (0-2.3). Direct comparison of the values for pathological urines with those for a reference population may offer more meaningful information concerning the integrity of the glomerular basement membrane than is provided by protein selectivity indices, and measuring a plasma protein such as albumin in urine may better define pathological proteinuria.

Differences in the binding of drugs to plasma proteins from newborn and adult man. II

Abstract: The binding of certain drugs to isolated fractions of plasma proteins obtained from newborn and adult man has been studied by equilibrium dialysis. For thiopental, desipramine, nitrofurantoin, sulfamethoxydiazine, meticillin and salicylic acid no difference was found between binding to the albumin fraction from newborns and adults. However, for thiopental, desipramine and promethazine binding to the globulin fraction was smaller in the newborns than in adults. Addition of bilirubin to the albumin fraction decreased the binding of nitrofurantoin, sulfamethoxydiazine and meticillin. No difference in the binding of meticillin to the albumin or globulin fractions from newborns and adults was found. The binding decreased, however, if both fractions were combined. Four mechanisms to explain the difference in binding between newborns and adults are discussed: (1) Displacement of drugs by bilirubin, (2) different binding properties of cord and adult albumin, (3) different properties of the globulins and (4) interaction of albumin with globulins in the newborn.

Changes in serum 3,3',5'-triiodothyronine (reverse T3) concentrations with altered thyroid hormone secretion and metabolism.

Abstract: A sensitive radioimmunoassay was developed for measurement of 3,3′, 5′-triiodothyronine (rT3) in unextracted serum using 8-anilinonaphthalene- 6-sulfonic acid (ANS) to inhibit binding of rT3 to serum proteins. Normal serum r⊂ concentrations were 23 ± 8 (SD) ng/dl. Serum rT3 concentrations were elevated in patients with hyperthyroidism (90 ± 49 ng/dl), T3-hyperthyroidism (36 ± 13 ng/dl), pregnant women (49 ± 9 ng/dl) and in cord blood (280 ± 143 ng/dl). Serum rT3 concentrations were decreased in hypothyroid patients (14 ± 5 ng/dl) and fell during T3 administration to normals. In hypothyroid patients receiving T4 replacement, serum rT3 concentrations varied directly with the dose of T4 between doses of 0.050 and 0.3 mg/day. The ratio of rT3 to T4 was elevated in the sera of hypothyroid and hyperthyroid patients, but was normal in hypothyroid patients receiving T4 replacement therapy. During propylthiouracil administration, serum rT3 concentrations were elevated; during methima-zole administration they did n...

The Thyroid and Its Control

Abstract: In considering thyroid hormone regulation and homeostasis, it is important to examine some characteristics of this hormone in relation to the others. The hor­ mones may readily be divided into two distinct physicochemical and biological classes. (Table 1). The protein and peptide hormones are water soluble and evidently exist in the plasma without demonstrable interaction with other serum proteins. These hormones have a rapid metabolic turnover with a half-time in minutes. Therefore it is not surprising to observe rather striking fluctuations in concentration in the blood within a few minutes in the case of all these peptide hormones, including parathyroid hormone, thyrocalcitonin, growth hormone, FSH, LH, prolactin, ACTH, MSH, TSH, vasopressin, insulin, secretin, angiotensin II, and glucagon (Table 1). Indeed, the amino acid hormones, epinephrine and norepinephrine, may fluctuate markedly within a few seconds. In contrast, the "target" hormones--cortisol, progesterone, estradiol, testoster­ one, and thyroxine-are relatively hydrophobic and exist in aqueous solution in the blood by virtue of their firm binding by one or more serum protein carriers (Table 1). The biologic half-times vary with the magnitude of the "free" or nonprotein­ bound moiety. Thus cortisol, which is about 95% protein bound and 5% unbound, has approximately a one-hr half-time, and thyroxine, more than 99.96% protein bound and less than 0.04% unbound, has a biologic half-time of turnover approx-

Molecular interactions in human atherosclerotic plaques.

Abstract: Most plasma proteins appear to be present in intima at concentrations that are a linear function of molecular weight and concentration in the plasma. Thus low density lipoprotein (LDL) (molecular weight, 2 X 10(6)) has the greatest retention relative to its plasma concentration, whereas the relative retention of albumin is only 15% of the relative retention of LDL. This gives rise to the concept that "whole plasma" crosses endothelium, and the steady state concentrations reflect rates of egress of the macromolecules, which in turn depend on molecular sieving. Fibrinogen is a major plasma protein in intima in addition to LDL and albumin, and there are also substantial amounts of the protease inhibitors alpha2-macroglobulin and alpha1-antitrypsin. Intima also contains insoluble derivatives of plasma--extracellular cholesterol, both free and esterified, and fibrin. The balances of intact LDL/"deposited" cholesterol and of fibrinogen/fibrin are closely linked with intimal morphology. Fibrinogen and electrophoretically mobile LDL are increased about threefold in gelatinous lesions, whereas there are only slight rises in fibrin and deposited cholesterol. In the deep layers of fibrous plaques, fibrin is increased fivefold and cholesterol up to thirtyfold. In these lipid-rich layers, LDL is rapidly lost on incubation of tissue samples, but in some gelatinous lesions it first increases and only decreases on longer incubation, suggesting release of a previously immobilized lipoprotein fraction. This immobilized lipoprotein was investigated by subjecting tissue samples to immunoelectrophoresis to remove mobile LDL and tissue enzymes, followed by treatment of the tissue with enzyme and measurement of the lipoprotein released on fresh immunoelectrophoresis plates. Plasmin or a crude collagenase released large amounts of lipoprotein from samples of amorphous atheroma lipid. For all samples the amount of lipoprotein released was highly correlated with the accumulation of deposited cholesterol, suggesting that immobilization of LDL may be an intermediate step in the irreversible deposition of extracellular cholesterol. Plasmin is highly effective in releasing immobilized lipoprotein, and the concentration of immobilized lipoprotein is significantly correlated with the concentration of insoluble fibrin, suggesting that the lipoprotein may in some way be immobilized by fibrin.

Levels of Plasma Proteins in Human and Rat Fetal CSF and the Development of the Blood-CSF Barrier

Abstract: High levels of albumin, alpha-fetoprotein (AFP), IgG, prealbumin and transferrin have been detected in cerebro-spinal fluid (CSF) of human fetuses between 14 and 25 weeks old. The concentration of each plasma protein in CSF was found to vary during the gestational period in relation to its serum levels and rate of synthesis and as a consequence of a reduced permeability of the blood-CSF barrier after 22 weeks. In fact, the higher CSF levels of AFP were detected in fetuses about 16 weeks old, while the highest values of albumin were observed in CSF from fetuses between 20 and 24 weeks old. Experimental work has shown that also in rats the permeability of the blood-CSF barrier is incomplete during fetal and perinatal life. When 125I-labelled albumin and IgG or 14C-oestrogen and testosterone were injected intraperitoneally in newborn rats, the labelled proteins and hormones were detected in fetal blood and CSF four hours after the injection. These results are discussed in view of the suggestion that maternal abnormal states with regard to hormones and antibrain antibodies may affect the development of the nervous system and unfolding of behaviour.

Purification of High Molecular Weight Kininogen and the Role of This Agent in Blood Coagulation

Abstract: Recent studies of individuals with high molecular weight (HMW) kininogen deficiency established the importance of this plasma protein for in vitro initiation of blood coagulation In the present study, HMW-kininogen was highly purified from human plasma by monitoring its clot-promoting activity, using Fitzgerald trait plasma as a substrate This preparation of HMW-kininogen revealed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (mol wt: 120,000) and released 1% of its weight as bradykinin upon incubation with plasma kallikrein HMW-kininogen specifically repaired impaired surface-mediated plasma reactions of Fitzgerald trait plasma, but did not affect those of Hageman trait and Fletcher trait plasma Kinin release from HMW-kininogen by trypsin, but not by plasma kallikrein, resulted in total loss of clot-promoting activity No inhibitors of coagulation were found when all kinin activity was removed from HMW-kininogen by trypsin The roles of HMW-kininogen, Hageman factor (HF, Factor XII), plasma prekallikrein (Fletcher factor), and plasma thromboplastin antecedent (PTA, Factor XI) in blood coagulation were studied in a purified system HMW-kininogen was absolutely required for activation of PTA by HF and ellagic acid The yield of activated PTA was proportional to the amount of HF, HMW-kininogen, and PTA in the mixtures, suggesting that, to activate PTA, these three proteins might form a complex in the presence of ellagic acid No fragmentation of HF was found under these conditions In contrast to HF, HF-fragments (mol wt: 30,000) activated PTA in the absence of HMW-kininogen and ellagic acid Thus, it appears that in the present study PTA was activated in two distinct ways Which pathway is the major one in whole plasma remains to be determined