Cost-effectiveness of splenectomy versus intravenous gamma globulin in treatment of chronic immune thrombocytopenic purpura in childhood.

Infusions of intravenous gamma-globulin (IVGG) are an effective, nontoxic therapy for chronic idiopathic thrombocytopenic purpura (ITP) that would be more widely accepted if the therapeutic agent were not so expensive. The costs and outcomes of managing such children with splenectomy and IVGG were modeled with Markov processes. Children unresponsive to one treatment were considered to have received the alternative.

Purification and characterization of a ferredoxin from acetate-grown Methanosarcina thermophila.

A ferredoxin, which functions as an electron acceptor for the CO dehydrogenase complex from Methanosarcina thermophila, was purified from acetate-grown cells. It was isolated as a trimer having a native molecular weight of approximately 16,400 and monomer molecular weight of 4,888 calculated from the amino acid composition. The ferredoxin contained 2.

Ferredoxin requirement for electron transport from the carbon monoxide dehydrogenase complex to a membrane-bound hydrogenase in acetate-grown Methanosarcina thermophila.

Cell extracts from acetate-grown Methanosarcina thermophila contained CO-oxidizing:H2-evolving activity 16-fold greater than extracts from methanol-grown cells. Following fractionation of cell extracts into soluble and membrane components, CO-dependent H2 evolution and CO-dependent methyl-coenzyme M methylreductase activities were only present in the soluble fraction, but addition of the membrane fraction enhanced both activities. A b-type cytochrome(s), present in the membrane fraction, was linked to a membrane-bound hydrogenase.

Clots of beta-fibrin. Viscoelastic properties, temperature dependence of elasticity, and interaction with fibrinogen-binding tetrapeptides.

Clots of human beta-fibrin, in which only (or predominantly) the B fibrinopeptide is released, were formed at 14 degrees C by copperhead venom procoagulant enzyme (CVE or venzyme), at pH 8.5, ionic strength 0.45.

Isolation and characterization of "Methanosphaera cuniculi" sp. nov.

A nonmotile, gram-positive, spherical organism was isolated from the intestinal tracts of rabbits. Both hydrogen and methanol were required for growth. No methane was produced from hydrogen-carbon dioxide, formate, acetate, methylamines, ethanol, or isopropanol.

"Adenoid cystic" carcinoma and adenoid basal carcinoma of the uterine cervix. A study of 28 cases.

Adenoid cystic carcinoma (ACC) and adenoid basal carcinoma (ABC) of the uterine cervix are rare tumors that have often been regarded as a single entity. We studied 28 cases of these neoplasms, with 14 cases in each category. Most patients were over 60 years of age, and there was a high proportion of black women.

Relative and absolute bioavailability of prednisone and prednisolone after separate oral and intravenous doses.

A randomized, four-way cross-over study was conducted in eight healthy male volunteers to determine the relative and absolute bioavailability of prednisone (PN) and prednisolone (PL). PN and PL were administered as single, oral 10-mg tablet doses and as 10-mg zero-order 0.5-hour intravenous infusions.

Multiple-dose cimetidine administration does not influence the single-dose pharmacokinetics of quinapril and its active metabolite (CI-928).

The potential effect of cimetidine on the pharmacokinetic profiles of quinapril and its active metabolite CI-928 was evaluated in eight healthy volunteers. Each subject received a single 40-mg quinapril dose on days 1 and 12 and cimetidine 300 mg four times daily on days 8 through 13. Serial blood and urine samples were collected for assay of quinapril and CI-928 concentrations.

EPR properties of the Ni-Fe-C center in an enzyme complex with carbon monoxide dehydrogenase activity from acetate-grown Methanosarcina thermophila. Evidence that acetyl-CoA is a physiological substrate.

The carbon monoxide dehydrogenase complex from acetate-grown Methanosarcina thermophila was further studied by EPR spectroscopy. The as purified enzyme exhibited no paramagnetic species at 113 K; however, enzyme reduced with CO exhibited a complex EPR spectrum comprised of two paramagnetic species with g values of g1 = 2.089, g2 = 2.

Locations of the hydrogenases of Methanobacterium formicicum after subcellular fractionation of cell extract.

The F420 hydrogenase of Methanobacterium formicicum was associated with membranes isolated by sucrose density gradient ultracentrifugation of cell extract. The methyl viologen hydrogenase was present in the soluble fractions. Column chromatography with phenyl-Sepharose CL-4B revealed that the F420 hydrogenase was strongly hydrophobic, suggesting that it associates with isolated membranes through hydrophobic interactions.

Influence of food on the pharmacokinetics of quinapril and its active diacid metabolite, CI-928.

A randomized two-way crossover study was conducted in 12 healthy volunteers to assess the effect of food on the pharmacokinetics of quinapril (CI-906) and its active metabolite, CI-928, after quinapril dosing. Forty-milligram oral quinapril doses were administered in a fasted or a fed state with a one-week washout period between treatments. No significant treatment differences were observed in quinapril and CI-928 values for maximum plasma concentration, area under the plasma concentration-time curve, or percentage of dose excreted in the urine.

The nonlinear pharmacokinetics of prednisone and prednisolone. II. Plasma protein binding of prednisone and prednisolone in rabbit and human plasma.

The protein binding characteristics of prednisone and prednisolone were determined in human and rabbit plasma and in a 4.7 per cent human serum albumin (HSA) solution. The influence of prednisolone on prednisone binding in human plasma was also examined.

Isolation of an enzyme complex with carbon monoxide dehydrogenase activity containing corrinoid and nickel from acetate-grown Methanosarcina thermophila.

Fast protein liquid chromatography of cell extract from methanol- or acetate-grown Methanosarcina thermophila resolved two peaks of CO dehydrogenase activity. The activity of one of the CO dehydrogenases was sixfold greater in acetate-grown compared with methanol-grown cells. This CO dehydrogenase was purified to apparent homogeneity (70 mumol of methyl viologen reduced per min per mg of protein) and made up greater than 10% of the cellular protein of acetate-grown cells.

Mechanistic studies of the coenzyme F420 reducing formate dehydrogenase from Methanobacterium formicicum.

Mechanistic studies have been undertaken on the coenzyme F420 dependent formate dehydrogenase from Methanobacterium formicicum. The enzyme was specific for the si face hydride transfer to C5 of F420 and joins three other F420-recognizing methanogen enzymes in this stereospecificity, consistent perhaps with a common type of binding site for this 8-hydroxy-5-deazariboflavin. While catalysis probably occurs by hydride transfer from formate to the enzyme to generate an EH2 species and then by hydride transfer back out to F420, the formate-derived hydrogen exchanged with solvent protons before transfer back out to F420.

Cloning, expression, and nucleotide sequence of the formate dehydrogenase genes from Methanobacterium formicicum.

The genes for the two subunits of the formate dehydrogenase from Methanobacterium formicicum were cloned and their sequences determined. When expressed in Escherichia coli, two proteins were produced which had the appropriate mobility on an SDS gel for the two subunits of formate dehydrogenase and cross-reacted with antibodies raised to purified formate dehydrogenase. The genes for the two formate dehydrogenase subunits overlap by 1 base pair and are preceded by DNA sequences similar to both eubacterial and archaebacterial promoters and ribosome-binding sites.

Relapsing central and peripheral demyelinating diseases. Unusual pathologic features.

We treated a patient who had a demyelinating peripheral neuropathy and a central nervous system inflammatory demyelinating disease. The unusual pathologic feature of dense infiltrates of atypical macrophages was observed in many areas of the brain; otherwise the process had several features in common with either multiple sclerosis or chronic relapsing experimental allergic encephalomyelitis. The illness followed "swine-flu" inoculation; exacerbation followed pneumococcal vaccination.

Molybdopterin cofactor from Methanobacterium formicicum formate dehydrogenase.

The molybdopterin cofactor from the formate dehydrogenase of Methanobacterium formicicum was studied. The cofactor was released by guanidine denaturation of homogeneous enzyme, which also released greater than 80% of the molybdenum present in the enzyme. The anoxically isolated cofactor was nonfluorescent, but after exposure to air it fluoresced with spectra similar to those of described molybdopterin cofactors.

Composition of the coenzyme F420-dependent formate dehydrogenase from Methanobacterium formicicum.

The coenzyme F420-dependent formate dehydrogenase from Methanobacterium formicicum was purified to electrophoretic homogeneity by anoxic procedures which included the addition of azide, flavin adenine dinucleotide (FAD), glycerol, and 2-mercaptoethanol to all buffer solutions to stabilize activity. The enzyme contains, in approximate molar ratios, 1 FAD molecule and 1 molybdenum, 2 zinc, 21 to 24 iron, and 25 to 29 inorganic sulfur atoms. Denaturation of the enzyme released a molybdopterin cofactor.