Apparent molecular weight of purified human factor VIII procoagulant protein compared with purified and plasma factor VIII procoagulant protein antigen.

We have compared apparent molecular weights of purified factor VIII procoagulant protein (VIII:C) and VIII:C antigen (VIII:CAg) by two different NaDodSO4 gel electrophoretic techniques. In a discontinuous NaDodSO4-7.5% polyacrylamide system, reduced and unreduced VIII:C, purified from commercial factor VIII concentrates by a monoclonal antibody immunoadsorption technique, showed a major doublet at mol wt 0.

Inheritance and the pigmentary dispersion syndrome.

We studied 23 patients in four families and have found that ten of these patients fulfill criteria for the pigmentary dispersion syndrome. Affected patients had characteristics associated with the pigmentary dispersion syndrome, which are: peripheral slit-like iris transillumination defects, increased trabecular meshwork pigmentation, Krukenberg spindle, myopia, and elevated intraocular pressure. We observed this syndrome to be transmitted in a direct linear manner from parent to sibling in three of the four families.

Biosynthesis of the subunits of factor VIIIR by bovine aortic endothelial cells.

The biosynthesis of the subunit of factor VIIIR was studied in bovine aortic endothelial cells by the techniques of immunoprecipitation and NaDodSO4/polyacrylamide gel electrophoresis. It was determined that the subunit is first produced as a Mr 240,000 glycoprotein precursor, which appears to undergo proteolytic cleavage at or about the time of secretion into the medium with a resultant change in apparent Mr to 225,000, the size of the mature subunit found in plasma. The Mr 240,000 species was detected within 10 min of the start of labeling of cells, but factor VIIIR was not detected in the culture medium until approximately equal to 50 min.

Role of calcium in the regulation of colonic secretion in the rat.

In vitro experiments were performed in rat colon to define the role of calcium in the regulation of electrolyte transport. Neither basal net sodium absorption (JNanet) nor JClnet was affected by varying serosal calcium from 0 to 3.0 mM, but both were decreased by 4.

Distribution of myelin-associated enzymes and myelin proteins into membrane fractions from the brains of adult shiverer and control (+/+) mice.

Shiverer, an autosomal recessive mutation in the mouse, is characterized by a severe deficiency in CNS myelin. The concentrations of the myelin basic and proteolipid proteins in the brains of two-month-old shiverer mice, although high enough to be measured, were much lower than in the control (+/+) brains. In contrast, the specific activities of the myelin-associated enzymes, 2',3'-cyclic nucleotide-3'-phosphohydrolase (CNP), 5'-nucleotidase, and carbonic anhydrase, were close to normal in the brains of the mutants.

Thrombin proteolysis of purified factor viii procoagulant protein: correlation of activation with generation of a specific polypeptide.

Factor VIII procoagulant protein (VIII:C) purified from commercial factor VIII concentrate contained multiple polypeptides ranging in mol wt from 79,000 to 188,000, all of which were removed from solution by a monoclonal anti-VIII:C antibody specific for a thrombin-sensitive epitope. In a time-course digest of the purified VIII:C using a trace amount of purified human alpha-thrombin, changes occurred in all VIII:C polypeptides during the activation and inactivation of VIII:C activity. The generation and destruction of a mol wt 92,000 polypeptide paralleled the increase and decrease in VIII:C activity, suggesting that this polypeptide represents an activated form.

Inhibition of lymphocyte function by 9-deazaadenosine.

9-Deazaadenosine (c9Ado), a novel C-nucleoside, has been found to inhibit lymphocyte-mediated cytolysis (LMC) in a time-dependent manner. c9Ado inhibited LMC by 50% at concentrations of 10 and 0.07 microM after drug-pretreatment periods of 3 and 22 hr, respectively, although a 1-hr pretreatment of cytolytic lymphocytes with 100 microM c9Ado had no effect upon this lymphocyte function.

Effect of tetrodotoxin on cholinergic agonist-mediated colonic electrolyte transport.

Muscarinic cholinergic agonists stimulate electrolyte secretion in the intestine; nicotinic agonists augment absorption. Recent studies in rabbit ileum suggest that nicotinic but not muscarinic agonists act via an intermediary neurotransmitter. These in vitro studies in rat colon were performed to determine whether tetrodotoxin (TTX), a potent neurotoxin, inhibits cholinergic agonist-induced changes in electrolyte transport.

Isoelectric focusing of human von Willebrand factor in urea-agarose gels.

An analytical technique has been developed for the isoelectric focusing (IEF) of plasma von Willebrand factor (vWF) in agarose gels containing urea. Under these conditions, vWF freely enters the gel and focuses without artifact. The focused vWF is visualized by staining fixed gels with 125I-labeled affinity-purified heterologous antibody.

Deamino-8-D-arginine vasopressin shortens the bleeding time in uremia.

In a randomized double-blind cross-over trial we gave either 1-deamino-8-D-arginine vasopressin or placebo to 12 patients with uremia, hemorrhagic tendencies, and prolonged bleeding times. After vasopressin infusion, all patients had shortened bleeding times, with the effect lasting for at least four hours in most cases. Platelet count, platelet cyclic AMP levels, platelet retention on glass beads, plasma fibronectin, serum thromboxane B2 and residual prothrombin, hematocrit, and plasma osmolarity were unchanged after vasopressin.

Carbonic anhydrase, 5'-nucleotidase, and 2',3'-cyclic nucleotide-3'-phosphodiesterase activities in oligodendrocytes, astrocytes, and neurons isolated from the brains of developing rats.

The activities of three myelin-associated enzymes, carbonic anhydrase, 5'-nucleotidase, and 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNP), were measured in oligodendrocytes, neurons, and astrocytes isolated from the brain of rats 10, 20, 60, and 120 days old. The carbonic anhydrase specific activity in oligodendrocytes was three- to fivefold higher than that in brain homogenates at each age, and, at all the ages, low activities of this enzyme were measured in neurons and astrocytes. The oligodendrocytes and astrocytes from the brains of rats at all ages had higher activities of the membrane-bound enzyme 5'-nucleotidase than was observed in neurons.

Type IIB von Willebrand's disease: differential clearance of endogenous versus transfused large multimer von willebrand factor.

The abnormal multimeric composition of plasma von Willebrand factor in type IIB von Willebrand's disease is transiently corrected after infusion of 1-deamino-[8-D-arginine]-vasopressin. However, the larger multimers released into the circulation disappear more rapidly in these patients than in type I von Willebrand's disease or normals. We demonstrate that the larger multimers of normal von Willebrand factor transfused into a type IIB patient are cleared from the circulation more slowly than multimers of similar size endogenously released from tissue stores.

Glycerolphosphate dehydrogenase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase and carbonic anhydrase activities in oligodendrocytes and myelin: comparisons between species and CNS regions.

Oligodendrocytes isolated from bovine white matter had higher specific activities of glycerolphosphate dehydrogenase (GPDH) and glucose-6-phosphate dehydrogenase (G6PDH) than were observed in homogenates of white matter or gray matter from bovine brains, whereas the activity of lactate dehydrogenase (LDH) was lower in the cells than in the homogenates. These observations suggest that G6PDH, as well as GPDH, is an oligodendrocyte-enriched enzyme. The 3 enzymes were also measured in myelin from bovine brains, rat spinal cords, and mouse brains, and, for each enzyme, the relative specific activity (RSA) in myelin was calculated by dividing the specific activity in myelin by the specific activity in the respective starting homogenate.

Muscarinic receptors on rat isolated colonic epithelial cells. A correlation between inhibition of [3H]quinuclidinyl benzilate binding and alteration in ion transport.

Muscarinic cholinergic agonists stimulate secretion or inhibit absorption in the large intestine both in vivo and in vitro, effects that are completely inhibited by atropine, a specific muscarinic antagonist. These studies were performed to determine if the muscarinic-induced alteration in electrolyte transport in rat colon was produced by muscarinic agonists binding directly to receptors on colonic enterocytes. We found that crude membranes prepared from rat isolated colonic epithelial cells had a specific, saturable, high affinity receptor for L-[benzilic-4,4-3H]quinuclidinyl benzilate, a potent muscarinic antagonist with an apparent dissociation coefficient of 0.

Aberrant multimeric structure of von Willebrand factor in a new variant of von Willebrand's disease (type IIC).

A variant of von Willebrand's disease has been identified in which sodium dodecyl sulfate agarose electrophoresis provides evidence that the von Willebrand factor present is structurally abnormal. Rather than the repeating triplet seen in normal subjects and in patients with the IIA and IIB variants, a repeating doublet was present in the propositus. None of the bands had the same mobility as bands in normal subjects or previously described von Willebrand's disease patients.

Multimeric structure of platelet factor VIII/von Willebrand factor: the presence of larger multimers and their reassociation with thrombin-stimulated platelets.

The multimeric structure of platelet factor VIII/von Willebrand factor (FVIII/vWF) in cell extracts and in collagen and thrombin releasates has been analyzed by SDS polyacrylamide gel electrophoresis followed by detection with 125I-anti-FVIII/vWF. Platelets contained larger multimers than those normally present in plasma. When secreted FVIII/vWF was analyzed, all platelets.

Increases of leukocyte tissue factor activity stimulated by red cells sensitized with human blood group alloantibodies.

Human Rh+ and A+ red cells sensitized with human anti-Rh and anti-A blood group alloantibodies are shown to stimulate large increases of tissue factor activity as compared to controls after incubation with leukocytes for 3-18 hours. As little as a 1/1280 dilution of human anti-Rh serum was stimulatory. Immunospecific effects in experiments with 5 different antibodies exclude possible artifacts resulting from contaminants such as endotoxin.