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Biomedical subjects

M Mimura

Publications and source records attributed to M Mimura.

At least 91 records · Page 5Linked to original sources

[Penicillin insensitive and resistant Streptococcus pneumoniae infection in children].

Five cases of penicillin insensitive or resistant pneumococcal infection in children were experienced during the period of 2 years since March, 1986. One isolate from middle ear showed the MIC of 4 micrograms/ml against penicillin-G. One isolate of insensitive pneumococcus was isolated from CSF specimen. Between 1976 and 1987, 59 isolates from 88 stocked pneumococcal clinical isolates were alive. These 59 strains were screened by oxacillin disc for insensitive and resistant pneumococcus. Five strains which were insensitive or resistant strains had inhibitory zone under 20 mm. The prevalence rate of insensitive or resistant pneumococcus since 1986 was 18%.

Humans↗

[Evaluation of toxic effects on yusho causal substances by chick embryo hepatic microsomal enzymes activities].

PCBs, non-ortho chlorine substituted PCBs (Co-PCBs), PCQs and (PCDFs + PCDDs), all of which contained similar compositions of those corresponding in yusho oil, were prepared from a PCB preparation used as a heat exchanger fluid. After dissolved in 1, 4-dioxane, they were applied into the air sac of white leghorn eggs incubated for 16.5 days at 37.5 degrees C. Forty eight hours after injection, the hepatic benzo(a)pyrene hydroxylase (AHH) and 7-ethoxyresorufin deethylase (EROD) activities were assayed. The average relative potencies of induction for the two microsomal drug metabolizing enzymes by (PCDFs + PCDDs), Co-PCBs, PCBs and PCQs were 100, 13.4, 0.0006 and 0.0004, respectively. The toxic effects for yusho disease by these substances were calculated from the relative enzyme induction potencies and the average concentrations in yusho oils with the production dates of February 9 and 10, 1968. Consequently, the relative toxicities of (PCDFs+PCDDs), Co-PCBs, PCBs and PCQs were 100, 13.2, 0.06 and 0.12, respectively. This result, as well as our previous investigations using rats and monkeys, insists that (PCDFs+PCDDs) are the primary causal agents for yusho disease. However, the Co-PCBs, which were recently detected in the yusho oils by us, were revealed to be fairly effective in yusho manifestation. In addition, it was cleared that the hepatic enzyme induction by the Co-PCBs fraction, which contained other several PCB isomers, was almost completely contributed by only Co-PCBs such as 3,4,3',4'-tetra- 3,4,5,3',4'-penta- and 3,4,5,3',4',5'-hexachlorinated biphenyls present in the fraction. A chemical uptake rate from the air sac by the chick embryo decreased significantly in the cases of extremely high doses of PCBs (10,000 micrograms/egg) and PCQs (3,333 and 10,000 micrograms/egg), and result the elevations of hepatic enzymes activities were depressed, indicating that the suitable chemical dose amount to be less than about 1,000 micrograms/egg.

Animals↗

Purification of a kininogenase from the venom of Agkistrodon caliginosus (Kankoku-Mamushi).

During the isolation of a capillary permeability-increasing enzyme from the venom of A. caliginosus, a kininogenase was also purified from the venom by gel filtration on Sephadex G-100, ion-exchange chromatographies on CM-Sephadex C-50 and DEAE-Sephadex A-50, and gel filtration on Sephadex G-75. By this procedure, 11 mg of the purified enzyme were obtained from 4 g of the venom. The purified enzyme was homogeneous by polyacrylamide disc gel electrophoresis at pH 8.3 and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and did not show any caseinolytic or clotting activity. The purified enzyme released bradykinin from purified bovine high mol.wt kininogen. The capillary permeability was increased by injection of the purified enzyme into the depilated skin of the back of a rabbit. It is supposed that the capillary permeability-increasing activity exerted by the enzyme is due to the release of bradykinin.

Animals↗

Some properties of a kininogenase from the venom of Agkistrodon caliginosus (Kankoku-Mamushi).

A kininogenase (bradykinin-releasing enzyme) from the venom of A. caliginosus, is a single polypeptide-chain glycoprotein with a mol.wt of about 33,500, which contains 10.1% carbohydrate. The isoelectric point of the enzyme is 3.5 and the enzyme has 274 amino acid residues based on the mol.wt of 33,500. The enzyme hydrolyzed arginine esters more readily than lysine esters, but did not hydrolyze tyrosine ester. The activity of the enzyme on hydrolysis of arginine ester or on liberation of kinin from purified bovine high mol.wt kininogen was inhibited by diisopropylfluorophosphate, indicating that the serine hydroxyl group is involved in enzymatic activity. Moreover, the enzyme split N-alpha-carbobenzoxy-Gly-Pro-Arg-p-nitroanilide (PNA), H.D.Val-Leu-Arg-PNA, H.D.Pro-Phe-Arg-PNA, H.D.Phe-pipecolyl-Arg-PNA and Pro-Phe-Arg-4-methylcoumaryl-7-amide more readily than the other chromogenic or fluorogenic substrates. This result indicates that the substrate specificity of the enzyme is broader than that of mammalian serine proteinases.

Crotalid Venoms↗

Partial purification of androgen receptor from hypertrophic human prostate.

For purification of androgen receptor from hypertrophic human prostate, solutions used for elution of androgen receptor from DNA Sepharose, affinity labeling of the receptor and ability of affinity gel to retain the receptor were examined. Elution with 20 mM pyridoxal 5'-phosphate of the receptor from DNA Sepharose was more efficient than that with diluted pyridoxal 5'-phosphate, high ionic solution or various concentrations of Mg++, 3H-dihydrotestosterone bromoacetate was applicable to covalent binding with partially purified androgen receptor regardless of the low specificity of the ligand. Affinity gel of thiopropyl-Sepharose 6B coupled to 17 alpha-(2', 3'-epoxy-propyl)-5 alpha-dihydrotestosterone was better than Affigel 102 coupled to N-[3-(3-oxo-5 alpha-androstane-17 beta-yloxycarbonyl) propionyloxy] succimide or aminoethyl-Sepharose 4B coupled to 17 alpha-carboxyethynyl testosterone with respect to the rate of retention of androgen receptor. In view of these observations, the following purification procedures were constructed: Removal of DNA Sepharose-binders from the cytosol, 40% ammonium sulfate precipitation, affinity chromatography using thiopropyl-Sepharose 6B coupled to 17 alpha-(2',3'-epoxypropyl)-5 alpha-dihydrotestosterone, and DNA Sepharose chromatography. After affinity labeling of the receptor thus obtained, the molecular weight was estimated. Some 1300-fold purification with a yield of 0.25% of the androgen receptor was achieved. The molecular weight of the receptor was mainly 45 K with 90 K in a lesser amount. The Stokes radius was calculated as 30 A.

Chromatography, Affinity↗

[High-dose CDDP therapy using a balloon-occluded arterial infusion (BOAI) in recurrent ovarian cancer].

An intraarterial high-dose CDDP, using a balloon catheter, has been infused into five patients with a recurrent ovarian cancer. The dose of CDDP was 150 mg-200 mg/body. Two patients experienced a partial tumor regression, whereas three showed no change. With regard to the toxicity, the NAG index (NAG activity/urinary creatinine) rose markedly in all patients, but toxicity was almost similar to that seen from a systemic administration. No significant catheter complication occurred.

Adult↗

Pattern formation in interacting and diffusing systems in population biology.

In this article, we have been mainly concerned with spatially non-uniform stationary states and their stability, motivated by pattern formation arising in population biology. The discussions are restricted to one-dimensional space, though real systems are always distributed in at least two-dimensional space. Even if we limit ourselves to small-amplitude solutions, it seems difficult to discuss the bifurcation problems in a manner similar to that for one-dimensional space. One of the reasons is that the bifurcation points are not easily found. However, some general theories have nearly been completed. There are a variety of phenomena of other patterns such as wave trains, wave fronts, pulse waves, target patterns, and rotating patterns in equations of reaction and diffusion. We have not discussed these here. Moreover, we emphasize that there are a lot of nonlinear diffusion problems which are different from the ones that were dealt with here. The book of Fife (1), for example, provides a good exposition on these problems.

Animals↗