Urinary Excretion Rate of Antithrombin III Related Antigen in Cerebral Stroke

The urinary excretion rate of antithrombin III related antigen (AT III RA) was examined in cerebral stroke. The excretion rate of AT III RA in cerebral hemorrhage (CH) was 12.33 ± 1.61 × 10-4 ml/min. The patients with CH were further classified into two groups: in group CH-I, whose consciousness state was stupor or further deteriorated including coma on admission, the excretion rate of AT III RA was 18.08 ± 2.50 × 10-4 ml/min. In group CH-II, whose consciousness state was clear on admission, the excretion rate of AT III RA was significantly lower than that in CH-I (6.20 ± 1.56 × 10-4 ml/min). The excretion rate in cerebral thrombosis (CT) was 1.96 ± 0.25 × 10-4 ml/min, which was significantly lower than that in CH. The excretion rate of AT III RA in both CH and CT was significantly higher than that in the healthy control group (0.29 ± 0.04 × 10-4 ml/min). Thus, AT III may change dynamically in cerebral stroke.

Assay of tyrosine 3-monooxygenase using the coupled nonenzymatic decarboxylation of dopa

Dopa was found to be decarboxylated nonenzymatically by ferricyanide over the range of pH 4.5 to 10. On the basis of this finding, a new assay method of tyrosine 3-monooxygenase using the coupled nonenzymatic decarboxylation by ferricyanide was developed. The new method was excellent not only in sensitivity and reliability, but also in convenience.

Accurate assay of dopa decarboxylase by preventing nonenzymatic decarboxylation of dopa

The nonenzymatic decarboxylation of dopa was completely blocked by both 2-mercaptoethanol and EDTA together over the wide range of pH. This finding made it possible to measure the activity of dopa decarboxylase precisely even at an alkaline pH value. The pH optimum of dopa decarboxylase was found to be pH 7.0 and the Km value for dopa was determined to be 4 X 10(-5) M.

Determination of alpha 2-plasmin inhibitor in body fluids

A sensitive method was developed to determine alpha 2 PI at very low concentrations. The minimal measurable concentration of alpha 2 PI was 0.5 ng/assay tube. Using this method, the alpha 2 PI in plasma, urine, amniotic fluid and cerebrospinal fluid was estimated. The mean values and standard deviation for plasma were 5.63 +/- 1.34 mg/dl in 25 males, and 5.29 +/- 1.62 mg/dl in 8 females; in the urine, 0.46 +/- 0.41 microgram/dl in 82 male samples, and 0.69 +/- 0.27 microgram/dl in 8 female samples; in amniotic fluid, 4.13 +/- 2.38 micrograms/dl in 16 samples; and in cerebrospinal fluid, 24.4 +/- 6.6 microgram/dl in 9 samples. The alpha 2 PI level in amniotic fluid was not correlated with the state of the pregnant mother, with that of the baby, or with the protein content or pH of the amniotic fluid.

Purification and some properties of tyrosine 3-monooxygenase from rat adrenal

Tyrosine 3-monooxygenase was purified to homogeneity, as judged by sodium dodecyl sulfate/polyacrylamide gel electrophoresis, from rat adrenal. The specific activity of the final preparation was approximately 1,600 nmol min-1 mg protein-1, which was much higher than the highest yet reported. The enzyme was markedly stabilized in the presence of glycerol, Tween 80 and EDTA. As judged by gel filtration on Ultrogel AcA 34, sodium dodecyl sulfate/polyacrylamide gel electrophoresis and cross-linking studies, the enzyme appeared to be composed of four identical subunits, each possessing a molecular weight of 59,000. The isoelectric point of the enzyme was estimated to be 6.7 in the presence of 8 M urea and 6.6 in its absence. Amino acid analysis of the enzyme revealed a fairly high content of serine residues in this protein. Purification of the enzyme caused changes in the kinetic properties of the enzyme. The Km for 2-amino-4-hydroxy-6-methyl-5,6,7,8-tetrahydropteridine decreased from 220 microM to 58 microM. The pH profile for the enzyme activity became more broad and the pH optimum was changed from an acid pH to a neutral pH. Although polyanions, such as heparin and dextran sulfate, markedly stimulated the activity of crude enzyme by increasing the V, they were much less effective in the activation of purified enzyme. A marked stimulation of the enzyme activity by phospholipids, such as phosphatidylserine, phosphatidylinositol, phosphatidylcholine and phosphatidylethanolamine, were not observed in both pure and crude preparations even at low concentrations of the pterin cofactor.

Inactivation of tyrosine 3-monooxygenase by acetone precipitation and its restoration by incubation with a sulfhydryl agent and iron

The acetone precipitation of a partially purified tyrosine 3-monooxygenase (L-tyrosine, tetrahydropteridine: oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2) resulted in the complete loss of enzymatic activity. The enzymatic activity was restored by incubation with iron and dithiothreitol. The restoration of the activity was a pH-, temperature- and time-dependent reaction. Since cobalt, nickel, copper, zinc, manganese, cadmium, magnesium calcium and barium ions were all ineffective in restoring activity, iron ion appeared to be specifically required in the restoration of the enzyme activity. Dithiothreitol could be partially replaced in the restoration step by glutathione, 2-mercaptoethanol or cysteine.

Differential effect of a microsomal deacetylase inhibition on the mutagenicity in Salmonella typhimurium of 2-acetylaminofluorene by liver homogenates of guinea pigs, mice and rats

The effect of paraoxon, a microsomal deacetylase inhibitor, on the mutant genicity of 2-acetylaminofluorene (AAF) by liver homogenates was compared between the AAF carcinogenesis-resistant guinea pigs and the susceptible mice and rats. The mutagenicity of AAF was mostly abolished by paraoxon, not only in the 3 kinds of untreated animals but also in guinea pigs treated with a combination of phenobarbital and 5,6-benzoflavone, whereas about 50% of the mutagenicity was resistant to paraoxon in treated mice and rats. We suggest that microsomal deacetylase activity is crucially involved in the mutagenic activation of AAF by guinea pig liver homogenates, while the enzyme activity other than the deacetylase activity is also important in the activation by liver homogenates from treated mice or rats.

Mutational biosynthesis of butirosin analogs. I. Conversion of neamine analogs into butirosin analogs by mutants of Bacillus circulans

By N-methyl-N'-nitro-N-nitrosoguanidine treatment, neamine-negative mutants which required neamine for biosynthesis of butirosins were obtained from a butirosin-producing organism Bacillus circulans. These mutants also produced butirosins from paromamine and could be divided into two types I and II. Mutants of type I could not produce butirosins from 2-deoxystreptamine, whereas those of type II could. Two typical mutants MCRL 5003 (type I) and MCRL 5004 (type II) could produce butirosin analogs, 3', 4'-dideoxybutirosins, 6'-N-methylbutirosins, 3', 4'-dideoxy-6'-N-methylbutirosins and 3', 4'-dideoxy-6'-C-methyl-butirosins from neamine analogs, gentamine Cla, 6'-N-methylneamine, 6'-N-methylgentamine Cla and gentamine C2, respectively.

Mutational biosynthesis of butirosin analogs. III. 6'-N-methylbutirosins and 3', 4'-dideoxy-6'-c-methylbutirosins, new semisynthetic aminoglycosides

Two pairs of butirosin analogs were isolated from the fermentation broths obtained by cultivating a neamine-negative mutant of the butirosin-producing organism Bacillus circulans in the medium supplemented with 6'-N-methylneamine and gentamine C2, respectively. These amtibiotics were characterized as 6'-N-mentylbutirosins A and B (NMB-A & NMB-B), and 3', 4'-dideoxy-6'-C-methylbutirosins A and B (DCB-A & DCB-B), respectively, by chemical and spectroscopic studies. NMB-A and NMB-B exhibited broad-spectrum antibacterial activities with in vitro potency similar to or slightly less than that for butirosin A, but with greater activities against butirosin-resistant strain which contains acetylating enzyme AAC-(6')-I. The activities of NMB-A and NMB-B against Pseudomonas aeruginosa strains were relatively weak. DCB-B had broad-spectrum activity, and exhibited greatly improved activity against butirosin-resistant organisms which contain acetylating enzymes AAC(6')-I and AAC(6')-IV, and phosphorylating enzyme APH(3')-II. These new butirosin analogs were also active against some of the clinical isolates resistant to butirosins, dibekacin and/or gentamicin.

Biological activity of neurotensin and its C-terminal partial sequences

A hypothalamic tridecapeptide, neurotensin, and its C-terminal partial sequences down to the dipeptide were synthesized. These peptides were assayed for smooth muscle contracting and blood pressure lowering properties using preparations of isolated stomach fundus, uterus and duodenum of the rat, isolated guinea pig ileum and rabbit carotid artery. Sequences of 6 or more terminal amino acids produced a strong stomach fundus contracting effect, the potencies of the fragments being approximately equivalent to or slightly more than that of the parent tridecapeptide. These fragments also elicited the ileum contracting activity, but the potencies were only one fifth to one tenth that of neurotensin. The tetra- or dipeptide hardly stimulated either the fundus or the ileum. The stimulating effect on the uterus or relaxing effect on the duodenum of neurotensin was not consistent. Rabbit blood pressure was lowered markedly by neurotensin and weakly by its dodecapeptide. From these results, the arginine or arginine-arginine residue down to the C-terminal leucine appears to be essential for the smooth muscle contracting activity of neurotensin. The full length sequence may be needed for the hypotensive effect.

Regional and subcellular distribution of gold in brain of gold thioglucose obese mouse

By employing neutron activation analysis, endogenous content of gold was estimated quantitatively in discrete brain areas and in subcellular fractions of the hypothalamus of gold thioglucose (GTG) induced obese mice. The highest concentration of gold was obtained in the ventromedial hypothalamus (VMH) reaching approximately 100 ng/mg wet tissue. Significantly higher concentrations were observed in other hypothalamic subareas followed by certain limbic areas and the thalamus, while in the cerebral and the cerebellar cortex the gold concentration was very low. Subcellularly, the hypothalamic gold was principally recovered in the supernatant fraction particularly after a hyposmotic shock treatment of the crude mitochondrial fraction. Contrary to GTG, treatment with gold thiomalate (GTM) did not induce obesity in the mouse, although considerable amount of gold was observed in the VMH, a finding suggesting the existence in the VMH of at least a two step mechanisms for inducing GTG obesity. To identify the satiety neuron transmitter, an analysis of certain enzyme activities involved in the synthesis of known transmitters, such as acetylcholine or gamma-aminobutyric acid (GABA), was made in the GTG-obese mice. There were no significant changes in any of the areas functionally related to the VMH.