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Biomedical subjects

K Ohta

Publications and source records attributed to K Ohta.

At least 649 records · Page 36Linked to original sources
PubMed1989

A novel form of cytochrome P-450 in beagle dogs. P-450-D3 is a low spin form of cytochrome P-450 but with catalytic and structural properties similar to P-450d.

A form of cytochrome P-450, P-450-D3, cross reactive with antibodies to rat P-450d was purified from liver microsomes of polychlorinated biphenyl (PCB)-treated female Beagle dogs to an electrophoretic homogeneity. Judging from the result of sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of P-450-D3 was estimated to be 54,000. The oxidized form of P-450-D3 showed a peak at 416 nm indicating that the cytochrome is mostly in a low spin state. The carbon monoxide bound reduced form of P-450-D3 showed a peak at 448 nm. In a reconstituted system, P-450-D3 catalyzed drug oxidations including benzphetamine and aminopyrine N-demethylations, 7-ethoxycoumarin and p-propoxyaniline O-dealkylations, and aniline and benzo(a)pyrene hydroxylations. The rate of aniline hydroxylation catalyzed by P-450-D3 was similar to that catalyzed by P-450c which is a low spin form of cytochrome P-450 purified from liver microsomes of PCB-treated rats, whereas the catalytic activities of P-450-D3 for 7-ethoxycoumarin O-deethylation and benzo(a)pyrene hydroxylation were considerably lower than those of P-450c. The amino terminal portion of P-450-D3 was found to be highly similar to those of P-450d, human P3-450 and P3-450 when four amino acid deletions were tentatively inserted between fifth and sixth amino acids from the N-terminal, but not that of P-450c which is a low spin form of cytochrome P-448 purified from rat liver microsomes. These results indicate that Beagle dogs possess a low spin form of cytochrome P-450 with spectral properties similar to P-450c but with catalytic and structural properties similar to P-450d.

Amino Acid Sequence↗
PubMed1989

A monoclonal antibody (MSN-1) against a newly established uterine endometrial cancer cell line (SNG-II) and its application to immunohistochemistry and flow cytometry.

To determine a phenotypic difference between normal endometrium and endometrial adenocarcinoma, a new monoclonal antibody (MSN-1) was produced by immunizing a new endometrial cancer cell line (SNG-II), which was established in 1981 from a 43-year-old Japanese woman with stage II uterine endometrial cancer. MSN-1 recognized the Lewis-b carbohydrate moiety on the cell surface glycolipid and seldom reacted immunohistochemically with normal endometrium but with about 90% of endometrial cancer cases. By application of MSN-1 to flow cytometry, the possibility of differentiating endometrial normal cells from cancer cells was demonstrated.

Adenocarcinoma↗
PubMed1989

Interspecies homology of cytochrome P-450: toxicological significance of cytochrome P-450 cross-reactive with anti-rat P-448-H antibodies in liver microsomes from dogs, monkeys and humans.

The mutagenic activation of various promutagens by liver microsomes from dogs, monkeys and humans was investigated. Dog liver microsomes efficiently catalyzed the mutagenic activation of Trp-P-2 and Glu-P-1 followed by IQ and AAF. Monkey liver microsomes were most active in the activation of IQ followed by Glu-P-1, AAF and Trp-P-2. Although there were remarkable individual differences, human liver microsomes were found to be most active in the mutagenic activation of IQ followed by Trp-P-2, Glu-P-1 and AAF. Antibodies against rat P-448-H inhibited the mutagenic activation of Glu-P-1, Trp-P-2 and IQ in rat and dog liver microsomes, and Glu-P-1 and Trp-P-2 in monkey liver microsomes. The activation of Glu-P-1 and IQ in human liver microsomes was also strongly inhibited by anti-P-448-H antibodies. The amounts of cytochrome P-450 cross-reactive with anti-P-448-H antibodies in human liver microsomes highly correlated with the capacity to activate Glu-P-1, Trp-P-2 and IQ but not AAF.

2-Acetylaminofluorene↗
PubMed1989

Dopamine D1 binding sites in the striatum of the mutant mouse weaver.

In the weaver mouse there is a major abnormality in the dopamine-containing innervation of the striatum. Dopamine islands from during development, along with some innervation of the non-islandic matrix; but during the first postnatal month much of the islandic innervation degenerates and there is a failure of the normal postnatal development of the diffuse nigrostriatal innervation. In the experiments reported here we analysed the distribution of D1 dopamine receptor-related binding sites in the weaver striatum in an effort to test the relationship between the dopamine-containing innervation of the striatum and the synthesis and distribution of dopamine receptors there. Dopamine D1 receptor binding sites labeled by the D1 specific antagonist [3H]SCH 23390 were studied in the striatum of 7-day and adult homozygous weaver (wv/wv) and homozygous control (+/+) mice. Saturation analysis of [3H]SCH 23390 binding in adult animals suggested that the dissociation constants of the binding sites are similar in mutants and controls. The Bmax values in the striatum of weavers were 16% higher than in the controls when the data were expressed as fmoles/mg protein. The protein content of the adult weaver's striatum was decreased by 15 to 30%, however, so that when values were expressed as fmoles/section, no significant difference between values in weavers and homozygous controls were found. Quantitative autoradiography supported the results of saturation analysis. We conclude that the apparent increase of [3H]SCH23390 binding sites in the mutants occurred as the result of shrinkage of the weaver's caudoputamen and that dopamine D1 receptor binding sites in the caudoputamen, as assessed with [3H]SCH 23390, are normal. The studies of regional distribution of [3H]SCH 23390 binding sites in 7-day and adult mice indicated that the characteristic postnatal transition of the [3H]SCH 23390 binding pattern from islandic to a diffuse distribution occurred normally in the weaver's caudoputamen. Thus, in spite of the degeneration and failure of development of the nigrostriatal innervation in weaver mice, D1 binding in the weaver's striatum undergoes the elaborate change in distribution of these sites that is a hallmark of normal striatal development.

Animals↗
PubMed1989

Follow-up study of reconstructed auricle in microtia: comparison of the results of the rib cartilage framework and the silicone rubber framework methods.

Plastic surgery for microtia had achieved fairly consistent good results since TANZER (Plast. Reconstr. Surg. 23: 1-15, 1959) and recently the modified methods have become popular. The authors did plastic surgery of auricles with the rib cartilage framework method from 1968 until 1986, and with the silicone rubber framework method from 1975 until 1986, and observed each postoperative course for 2 to 10 years. The operative results and the merits and the demerits of each method are reported here. The subjects were 49 ears for the rib cartilage framework method (17 of the former period, 1968-1977, and 32 of the latter, 1978-1986), and 20 ears for the silicone rubber framework method. The operation was performed in 3 stages according to the modified Tanzer's method. The results of operations were subjectively assessed as "satisfied," "fairly satisfied," "a little unsatisfied," and "unsatisfied." The results were as follows: 1) in the rib cartilage framework method, there were 21 satisfied cases (43%), 17 fairly satisfied cases (35%), and 5 unsatisfied cases (10%); 2) there were 8 satisfied cases (40%), 5 fairly satisfied cases (25%), and 6 unsatisfied cases (30%) in the silicone rubber framework method. From the aspect of postoperative management, the rib cartilage framework method is now better but the authors expect the silicone rubber framework method will be improved and used more extensively in the future.

Cartilage↗
PubMed1989

Purification and properties of UDP-glucuronyltransferase from kidney microsomes of beta-naphthoflavone-treated rat.

Rat kidney microsomal UDP-glucuronyltransferase activities toward phenoic xenobiotics were enhanced about 4-5-fold by treatment of the animal with beta-naphthoflavone. The transferase activity toward serotonin, an endogenous substrate, was also enhanced about 7.5-fold. A form of UDP-glucuronyltransferase was purified from kidney microsomes of beta-naphthoflavone-treated rat by solubilization with sodium cholate and two steps of column chromatography, the first with DEAE-Toyopearl (fast flow rate liquid chromatography:FFLC) and the second with UDP-hexanolamine Sepharose 4B (affinity chromatography). These procedures gave about 39-fold purification and 11.5% yield of the transferase activity toward 1-naphthol. The preparation, tentatively termed "GT-2," was highly purified as judged from the single protein band (Mr 54,000) on sodium dodecylsulfate (SDS)-polyacrylamide slab gel electrophoresis. It catalyzed the glucuronidation of not only phenolic xenobiotics such as 1-naphthol, 4-nitrophenol, and 4-methylumbelliferone but also serotonin. From the result that apparent molecular weight of GT-2 was reduced to 50,000 by endo-beta-N-acetylglucosaminidase H (Endo H)-treatment, GT-2 was found to be a 50,000 Da polypeptide carrying "high mannose" type oligosaccharide chain(s). The NH2-terminal sequence of 20 residues of GT-2 was determined to be Asp-Lys-Leu-Leu-Val-Val-Pro-Gln-Asp-Gly-Ser-His-Trp-Leu-Ser-Met-Lys-Glu- Ile-Val . It was observed that there are two amino acids substitutions in the seven NH2-terminal residues in comparison with GT-1, which was purified from liver microsomes of 3-methylcholanthrene-treated rat. The NH2-terminal sequence of GT-2 was found to be homologous with the NH2-terminal sequence from the 26th to 46th amino acid residue of various UDP-glucuronyltransferase cloned by other investigators.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1989

Spontaneous regression in murine hypersensitivity pneumonitis: lack of immunological tolerance.

We have reported a murine model of hypersensitivity pneumonitis (HP) by transnasal administration of Thermoactinomyces vulgaris (Tv) antigen and shown a potential usefulness in the study of the immunopathogenesis of HP. Since we observed spontaneous regression (SR) of the lung lesions with continuous administration of Tv antigen in our model of HP, attempts were made to study if SR is caused by immunological tolerance. The titers of anti-Tv IgG antibody in serum and bronchoalveolar lavage fluid (BALF) did not show any decrement during the period of SR, at the 6th and 9th weeks after the first administration of the antigen. A delayed-type hypersensitivity reaction, i.e. footpad swelling with Tv antigen, did not change significantly during the SR period. Analysis of BALF cells disclosed that Lyt-2-positive cells, i.e. suppressor/cytotoxic T lymphocytes, did not increase to predominate Lyt-1-positive cells. The lymphocyte proliferation test with Tv antigen showed that the lung lymphocytes reacted to Tv antigen as well as concanavalin A during the period of SR in a similar magnitude as in the development period (3 weeks after the first treatment with the antigen). Treatment with cyclophosphamide before the period of SR resulted in no delay of SR. Finally, the adoptive cell transfer of spleen T cells obtained from mice during the SR period did not manipulate the development of granulomatous pneumonitis in the recipient mice. We concluded that the events causing SR in our murine model of HP may not involve the induction of immunological tolerance in humoral or cellular immunity.

Alveolitis, Extrinsic Allergic↗
PubMed1989

Enhanced erythrocyte aggregability in occlusive cerebrovascular disease.

We measured the rate of erythrocyte aggregation using our whole-blood aggregometer in 80 patients with occlusive cerebrovascular disease during the acute and chronic phases. We compared the data with values for 38 age-matched healthy controls. Mean +/- SD erythrocyte aggregability of the patients during both the acute phase (0.145 +/- 0.21/sec, n = 35) and the chronic phase (0.139 +/- 0.21/sec, n = 45) was higher than that in the controls (0.123 +/- 0.21/sec, n = 38; p less than 0.01). Erythrocyte aggregability was positively correlated with the plasma concentration of globulin and fibrinogen and inversely correlated with the albumin:globulin ratio. However, these correlations did not necessarily exclude the possibility that some unknown substance(s) released from ischemic tissue might enhance erythrocyte aggregability.

Acute Disease↗
PubMed1989

Coexistence of cerebral aneurysm and renal angiomyolipoma--case report.

We report a late middle-aged female in whom a renal angiomyolipoma was discovered by ultrasound after she developed hemorrhagic shock following surgery for a ruptured cerebral aneurysm. This appears to be the first reported case of the coexistence of a cerebral aneurysm and a renal angiomyolipoma. The associations between cerebral aneurysm and various other pathological conditions are discussed, and attention is directed to diagnostic techniques and characteristic findings.

Female↗
PubMed1989

Increase in red blood cell aggregability following experimental occlusion of the middle cerebral artery in cats.

Red blood cell (RBC) aggregability has been reported to be enhanced in patients with ischemic cerebrovascular disorders. We investigated whether the ischemic insult per se causes such enhancement of RBC aggregability. Fifteen cats were anesthetized and the middle cerebral artery (MCA) was occluded. Successful occlusion was confirmed from a sudden decrease in cerebral blood volume. Venous blood samples (2 ml) were obtained from the femoral vein before and after MCA occlusion. The blood was immediately mixed with disodium EDTA (2 mg), and the RBC aggregation rate (RBC-A) was measured employing a whole-blood RBC aggregometer. The control value for RBC-A was 0.213 +/- 0.007/s (mean +/- SEM). RBC-A was already increased at 1 h after the occlusion (0.229 +/- 0.007/s, p less than 0.01) and maintained a significantly high level until 2 h after the occlusion (0.229 +/- 0.018/s, p less than 0.05) as compared with the control value. These results suggest that a brief insult of cerebral ischemia brought about an enhancement of the RBC aggregability in the circulating blood.

Animals↗
PubMed1989

[Pulmonary complications subsequent to fractured neck of the femur in the elderly].

Fracture of the neck of the femur (FNF) is a common disorder in the elderly. A total of 618 cases consisting of 117 males and 501 females, whose age was 65 years or more, were enrolled in a prospective study. A total of 45 cases among them revealed pulmonary complications. These were divided into the following three groups: Group 1 (4.7%) who had respiratory disease(s) or symptoms prior to the fracture; Group 2 (1.9%), diagnosed as having pulmonary thromboembolism (PTE). In Group 3 (0.6%), PTE was a possible diagnosis but it was not distinguished from pneumonia in precise. In the patients of group 2 and 3, respectively, the following respiratory symptoms were observed: dyspnea (31.3%), productive cough (25%), syncope (12.6%), chest pain (6.3%), tachycardia (46.7%), and tachypnea (50%). An abnormal chest roentgenogram was found 56.4% in both group 2 and 3. Seven patients in group 2 showed remarkable reduction of PaO2 on admission, however these all recovered within 7 days without any thrombolytic treatment. The prevalence of PTE caused by FNF in the elderly was close to that in younger cases, but the clinical symptoms were less in the former.

Aged↗