Search PubMed⌕ Search

Biomedical subjects

D Green

Publications and source records attributed to D Green.

At least 253 records · Page 14Linked to original sources
PubMed1990

Hematin: effects on hemostasis.

Extensive studies performed over the past 6 years have shown that a degradation product of hematin produces a unique coagulopathy, characterized by thrombocytopenia with platelet degranulation, alteration in the function of numerous clotting and fibrinolytic proteins, and reversible changes in endothelial cells. With the use of degraded hematin, it can be demonstrated that platelet aggregation is stimulated, that platelet adhesion to endothelial cells is enhanced, that the dissociation of factor VIII: C from von Willebrand factor is inhibited, and that the binding of the factor VII/von Willebrand factor complex to platelets is impaired. Even freshly reconstituted solutions of sorbitol-stabilized hematin affect hemostasis and induce thrombophlebitis, presumably because of in vivo degradation of the hematin. Recently, a new formulation of hematin, heme arginate, has been shown to be extraordinarily stable and to have virtually no effects on coagulation. This review compares and summarizes the effects of these various hematin compounds on hemostasis.

Arginine↗
PubMed1989

Nonenzymatic glycation of human blood platelet proteins.

We studied 11 diabetic patients, all of whom had severe atherothrombotic disease, and 11 normal controls. Overall glycation was assessed by the extent of incorporation of [3H]-NaBH4 into fructosyl lysine separated from whole platelet proteins following aminoacid analysis. Fructosyl lysine represented 5.7% +/- 1.0 S.D. of the total radioactivity in the normal whole platelet samples. Increased glycation was observed in platelets from 5 of the 11 diabetics. Platelet glycation did not correlate with glycation of hemoglobin or albumin. The pattern of glycation of various platelet proteins in whole platelets, as determined by the incorporation of [3H]-NaBH4 into electrophoretically separated proteins did not display selectivity, although myosin and glycoproteins IIb and IIIa showed relatively increased levels of [3H]-NaBH4 incorporation. Artificially glycated platelet membranes exhibited glycation mainly in proteins corresponding to the electrophoretic mobility of myosin, glycoproteins IIb and IIIa.

Amino Acids↗
PubMed1989

6-bis-(2-chloroethyl)amino-6-deoxy-D-galactopyranose hydrochloride: synthesis, chemical characterization, murine P388 antitumor activity, and bone marrow toxicity.

6-Bis-(2-chloroethyl)amino-6-deoxy-D-galactopyranose hydrochloride has been synthesized, characterized, and evaluated for antitumor activity and bone marrow toxicity in mice. The 1D- and 2D-NMR studies show the compound to exist as a beta-anomer chair conformation (23%), alpha-anomer chair conformation (22%), and several equilibrating boat conformations or furanose forms (55%). A single ip LD10 dose of 15.0 mg/kg produced antitumor activity against the murine P388 leukemia superior to that achieved with an equitoxic dose of nitrogen mustard. In normal mice, this 15.0-mg/kg dose produced minimal depression of peripheral white blood cells and no significant decrease in absolute neutrophil counts. A reduction in toxicity was also demonstrated for human bone marrow CFU-GM, as compared with nitrogen mustard and L-PAM. This and other sugar-containing mustard compounds may represent a class of antineoplastic alkylating agents with reduced bone marrow toxicity.

Alkylating Agents↗
PubMed1989

Polymorphism of three HLA-DR7 bearing major histocompatibility complex extended haplotypes.

We have studied the complexity of HLA class II region in DR7 bearing extended haplotypes by restriction fragment length polymorphism (RFLP). Genomic DNA from homozygous cell lines and from unrelated individuals was digested with a number of restriction endonucleases and probed with DR alpha, DR beta, DQ alpha and DQ beta cDNA probes. We detected RFLPs that distinguished subspecificities of DRA, DRB1, DQA1 and DQB1 chain genes. On the basis of polymorphism in these genes, three distinct types of DR7 bearing extended haplotypes could be identified: (1) B44 or Bw47 or B14, DR7a (DRA1, B1.1), DRw53a (DRA1,B4), DQw2 (DQA1.1, B1.1); (2) B13 or B40, DR7b (DRA1, B1.2), DRw53a (DRA1, B4), DQw2 (DQA1.1, B1.1); and (3) Bw57, DR7c (DRA2, B1.2), DRw53b (DRA2, B4), DQw9 (DQA1.2, B1.2). Available evidence indicates that independent examples belonging to a haplotype were similar in RFLP patterns, suggesting that most examples of an extended haplotype belonging to a subtype are similar. The results in the present study have important implications for immune function and disease susceptibility.

Blotting, Southern↗
PubMed1989

Measurement of pharyngeal volume by digitized magnetic resonance imaging. Effect of nasal continuous positive airway pressure.

Pharyngeal size is thought to play an important role in the pathogenesis of snoring and obstructive sleep apnea. It has been hypothesized that nasal continuous positive airway pressure (CPAP) works by enlarging pharyngeal size and splinting the airway open. In this study, we selected 12 heavy snorers and abolished their snoring with nasal CPAP in our sleep laboratory. Using magnetic resonance imaging and a computer program utilizing a digitizing pad, we measured these awake subjects' pharyngeal volumes without and with the nasal CPAP apparatus on at the level used to abolish their snoring. We found an average 27.7% increase in pharyngeal volume with nasal CPAP. We have visually shown an increase in pharyngeal size with the use of nasal CPAP in a cohort of heavy snorers.

Adult↗
PubMed1989

Involvement of cholecystokinin receptors in the adverse effect of glucocorticoids on diet-induced necrotizing pancreatitis.

The mechanism that explains the association between corticoids and acute pancreatitis is unknown. Our hypothesis was that chronic glucocorticoid treatment could adversely affect the course of hemorrhagic pancreatitis by acting through cholecystokinin (CCK) receptors. Acute necrotizing pancreatitis was induced by feeding young female mice a choline-deficient, ethionine-supplemented (CDE) diet for 60 hours. Treatment with hydrocortisone (10 mg/kg/day) was begun 1 week before pancreatitis. At the onset of the CDE diet, a group of hydrocortisone-treated mice were also given the CCK receptor antagonist CR-1409 (5 mg/kg three times a day). Control mice received injections of saline solution. A follow-up of 336 hours was conducted for survival analysis. Hydrocortisone given alone did not produce pancreatitis. Hydrocortisone, however, did increase the pancreatic necrosis caused by the CDE diet (from 40% to 70%) and significantly reduce survival (from 40% to 9%). CR-1409 completely abolished the adverse effects of hydrocortisone on pancreatitis. We measured amylase release by dispersed pancreatic acini from mice chronically treated with hydrocortisone in response to CCK-8. Treatment with hydrocortisone increased both the sensitivity and the responsiveness of the pancreas to CCK-8. We conclude that glucocorticoids alone may not induce acute pancreatitis, but they can increase the risk of a more severe form of pancreatitis developing. The glucocorticoid effect appears to be attributable to a CCK receptor-mediated sensitization of the pancreas to endogenous CCK. Thus, CCK-receptor blockade may improve survival in necrotizing pancreatitis associated with chronic glucocorticoid treatments.

Amylases↗
PubMed1989

Second malignant neoplasms following childhood Hodgkin's disease: treatment and splenectomy as risk factors.

The risk of second malignant neoplasm (SMN) was evaluated in 979 children with Hodgkin's disease. This cohort was diagnosed between 1955 and 1979 at one of the institutions of the Late Effects Study Group. Solid tumors, non-lymphocytic leukemia, and non-Hodgkin's lymphoma (NHL) developed in 18, 17, and 3 patients, respectively. The estimated cumulative probability of developing any SMN was 2% at 5 years from diagnosis, 5% at 10 years, and 9% at 15 years. The incidence is ninefold greater than the risk of acquiring cancer in 19 year-olds, the median age at which the diagnosis of SMN was made in this study population. For leukemia and NHL the corresponding probabilities were 1%, 3%, and 4% for the group as a whole but were increased (2%, 6%, and 8%) in patients who had suffered one or more recurrences. In order to analyze the risk of leukemia and NHL associated with alkylating agent chemotherapy, each patient was assigned a score of one for each alkylating agent administered for a 6-month period. Scores of 2, 4, 6, and 8 were associated with probabilities of leukemia or NHL of 2%, 3%, 6%, and 10%, respectively. In a multivariate analysis for leukemia/lymphoma that included AAD score, stage, and splenectomy, the effect of AAD score and splenectomy did not change substantially compared to the univariate results. AAD score remained statistically significant (P = .0001), and splenectomy was of borderline significance (P = .09). Of the 18 solid tumor SMNs, 15 developed within the field of radiation, and one other developed in tissue irradiated 34 years earlier for hemangioma. This study of a large and unselected group of children with Hodgkin's disease who received a variety of therapies demonstrates that children are as likely as adults to develop acute leukemia after alkylating agents and solid tumors in the field of radiation therapy.

Adolescent↗
PubMed1989

Compression sclerotherapy techniques.

Sclerotherapy refers to the technique in which a substance is intravascularly deposited for the purpose of eradicating that blood vessel. This procedure may be utilized for therapeutic or cosmetic intentions. Excellent results can be obtained, but technical expertise and extensive experience are requisite. The proper techniques of sclerotherapy are elucidated, with emphasis on explaining the rationale for the methods proposed.

Bandages↗