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Biomedical subjects

H Okabe

Publications and source records attributed to H Okabe.

At least 523 records · Page 29Linked to original sources
PubMed1980

o-Toluoylcholine as substrate for measurement of serum pseudo-cholinesterase activity.

New synthetic substrates for serum pseudo-cholinesterase activity were compared with the common substrates for the routine assays, with regard to reactivity, specificity and stability; o- and m-toluoylcholine as well as o- and m-toluoyldimethylaminoethanol esters had selective specificities for pseudo-cholinesterase. The last three substrates, however, were unstable in solution at 4 degrees C. On the other hand, o-toluoylcholine could be stored in solution for several days with no appreciable degradation, and it was extremely stable with regard to pH and temperature. No or little hydrolysis of o-toluoylcholine was observed by various enzymes other than pseudo-cholinesterase. The enzymatic method using o-toluoylcholine as substrate was reproducible, and the results correlated well with those obtained using butylthiocholine as substrate and 5,5'-dithiobis-(2-nitrobenzoic acid) as color reagent. In conclusion, o-toluoylcholine is a favorable substrate for the determination of serum pseudo-cholinesterase activity.

Butyrylcholinesterase↗
PubMed1980

Correlation of quantitative changes of gastric mucosal glycoproteins with aspirin-induced gastric damage in rats.

Quantitative changes of gastric mucosal glycoproteins with the gastric damage induced by acetylsalicylic acid (aspirin) in rat have been studied. Gastric injury was easily observed macroscopically within one hour after the oral administration of aspirin. The most striking changes occurred at five hours, and the injury was overcome within nine hours after dosing. The glycoproteins extracted from rat stomack with Tris buffer containing Triton X-100 were fractionated on Bio-Gel A-1.5 m column chromatography and divided into three fractions. The first peak, corresponding to gastric mucus macromolecular neutral and acidic glycoproteins with or without sulphate (Fr.I), was diminished after aspirin administration. A considerable alteration of Fr.I (49% of control) appeared at three hours, and a gradual return to the control value was observed subsequently. The changes in the amount of the glycoproteins were detected before the macroscopical changes of the mucosa. These results suggest that gastric ulceration induced by aspirin may be caused by a deficiency of gastric mucus macromolecular glycoproteins of gastric mucus.

Animals↗
PubMed1980

Enzymic determination of free fatty acids in serum.

We describe the enzymic determination of free fatty acids in serum with use of acyl-CoA synthetase (EC l.2.1.3), acyl-CoA oxidase (no EC no. assigned) and peroxidase (EC 1.11.1.7). The free fatty acids are activated by acyl-CoA synthetase in the presence of ATP and coenzyme A. The acyl-CoA formed is oxidized by acyl-CoA oxidase to enoyl-CoA with simultaneous production of hydrogen peroxide, which is oxidatively coupled with 4-amino-antipyrine and 2,4-dibromphenol in the presence of peroxidase to yield a product that absorbs maximally at 505 nm. Standard curves prepared with various kinds of fatty acids are linear to at least 2.0 mmol/L and are practically congruent. Ascorbic acid or bilirubin interferes slightly. Results by the present method correlate well with those by the colorimetric method involving 2-(2-thiozolylazo)-p-cresol (r = 0.98). Replicate analyses of standard solution and of two kinds of control sera demonstrated the following between-assay precision: mean absorbance 0.224 (SD 0.002), CV 0.85%; mean concentration, 326 (SD 7.3) and 1076 (SD 22.7) mumol/L, CV 2.24 and 2.11%, respectively.

Acyl Coenzyme A↗
PubMed1980

[Studies on the effects of thiamine deficiency on rat testes (author's transl)].

Using male rats fed a thiamine deficient diet from the age of 35-days, an investigation was made of the effects on testicular tissue after 30 days of thiamine deficiency. It was found that: 1) In the thiamine deficient group, the seminiferous tubuli of rats having erections had atrophied and there was a decrease in the number of primary spermatocytes and spermatogonium, but a moderate increase in the number of sertoli cells. Furthermore, spermatids and spermia were rarely seen in tubuli which contained multinuclear giant cells. In the group of rats not having erections, moderate interstitial edema was seen and there was notable degeneration and reduction in the number of primary spermatocytes and spermatogonium. 2) In the group injected with thiamine hydrochloride after 21 days of thiamine deficient feeding, moderate interstitial edema was seen and the seminiferous tubuli were atrophic. 3) In the pair-fed group, there was a marked edema of interstitial tissue and an atrophy of seminiferous tubulus. 4) With regard to the effects of thiamine deficiency on the polyamine contents of the testicles, there was a marked decrease in spermidine content on the 12th day of feeding and a marked increase of spermine content on the 30th day. The spermidine/spermine ratio, which is high during periods of active cell differentiation and proliferation, was found to be significantly decreased in the thiamine deficient animals on both the 12th and 30th days of thiamine deficiency. Thus, it was clarified that thiamine deficiency causes disturbances in cell differentiation and proliferation in rat testes.

Animals↗
PubMed1979

High and low density lipoprotein cholesterol in myocardial and cerebral infarction.

High density lipoprotein (HDL) and low density lipoprotein (LdL) cholesterol levels were measured in fasting blood samples from 950 healthy subjects and 188 aged patients by a new simple method. The HDL-cholesterol levels and HDL/LDL-cholesterol ratios are significantly higher in females than in males. In the healthy subjects, there are slight decreases in the levels of HDL-cholesterol and HDL/LDL-cholesterol ratio with aging in both sexes. The patients with myocardial infarction had significantly lower HDL-cholesterol levels and HDL/LDL-cholesterol ratios as compared to those of the group without infarction. On the contrary, no differences in total lipoprotein cholesterol levels were observed in the patients with cerebral infarction. The results, obtained in respect of electrocardiographic findings after the isoproterenol stress test, suggest that the HDL-cholesterol levels and HDL/LDL-cholesterol ratios may be related not only to the established myocardial infarction, but also to the presence of coronary atherosclerosis and stenosis.

Adult↗
PubMed1979

Improved method for simultaneous determination of cholesterol in high- and low-density lipoproteins.

A previously described procedure for simultaneous determination of cholesterol in high- and low-density lipoproteins (HDL and LDL) [Clin. Chem. 24, 1504--1508 (1978)] has been improved by using centrifugation instead of ultrafiltration. Addition of NICl2 (2.0 mmol/L) to the reagent produced a good separation of HDL from the complex of low- and very-low-density lipoprotein-heparin-Ca2+ on centrifugation at 3000 rpm for 15 min. Replicate analyses for high-density lipoprotein cholesterol by the present method demonstrated the following intra-assay precision: mean = 389 mg/L, SD = 11 mg/L, CV = 2.8%. The present (y) and original (x) methods gave results that agreed reasonably well (n = 50, r = 0.960, y = 1.0x + 0.9). The enzymic method for HDL- or (HDL + LDL)-cholesterol after the separation of their fractions gave erroneous results, in particular in the cases of hyperbilirubinemic sera and in (HDL + LDL) fractions.

Cholesterol↗