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Biomedical subjects

M Kawamura

Publications and source records attributed to M Kawamura.

At least 793 records · Page 44Linked to original sources
PubMed1986

[Studies on the cellular immune response in patients with urinary bladder carcinoma. XI: Evaluation of specific ADCC activity].

We previously reported that the activity of antibody dependent cell-mediated cytotoxicity (ADCC) of lymphocytes from the patients with urinary bladder carcinoma was lower than that of normal subjects. We performed the specific ADCC assay using SRBC as the target cells, coated with tumor extract from the urinary bladder carcinoma. At the same time, the antiserum was collected from the immunized rabbit by the same tumor extract. The addition of the antiserum from the immunized rabbit gave the highest value for the patient sub-group that produced a precipitin band (Ouchterlony gel diffusion assay). Therefore it is suggested that the reaction of lymphocytes to tumor associated antigens is maintained to a considerable extent, although ADCC activity of the patient group was decreased. However, the antibody producing phenomenon toward the tumor associated antigen might be restrained.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1986

[Incidence of infection after transurethral prostatectomy].

The incidence of preoperative and postoperative infections among 46 patients who underwent transurethral prostatectomy (TUR-P) was studied. Perioperative antibacterial schedule was as follows: one gram of cefotaxime (CTX) was intravenously injected just before the beginning of TUR-P, One gram of the antibiotic was intravenously infused once more on the day after TUR-P, twice on the next day, and once during each of the succeeding 2 days. Thirteen cases out of 46 (28.3%) had significant preoperative bacteriuria (greater than or equal to 1 X 10(4)/ml), but the postoperative eradication of the bacteria was observed for 10 of the 13 cases (76.9%). Among the 33 cases that did not have significant preoperative bacteriuria, only one case developed significant bacteriuria. In this case, a non-significant bacterial contamination of the urine had been observed before TUR-P.

Aged↗
PubMed1986

[Alexia with agraphia produced by localized infarction in the inferior posterior region of the left temporal lobe].

There have been several reports on alexia with agraphia due to hemorrhage or trauma in the inferior posterior region of the left temporal lobe since Yamadori (1982) first reported a case of cerebral hemorrhage. We presented the first case of alexia with agraphia due to a circumscribed infarct in the inferior posterior region of the left temporal lobe. A 65-year-old right-handed man had an acute onset of inability to read Japanese "kana" letters and to write any letters. He had no difficulty in speaking or understanding. Neurological examination on admission was normal except for homonymous quadrantanopia in the right upper field. Neuropsychological findings: Spontaneous speech was fluent without dysprosody. There were no disturbances in auditory understanding or in repetition. He could read Japanese "kanji" characters correctly, however, he could not read any "kana" letters. Writing was also disturbed severely even as to his address, name or telephone number. Calculation was also difficult. There were no disturbances in naming colors, no ideomotor or constructional apraxia nor visual agnosia. X-ray computed tomography (CT) scan showed a faint low density area with ring enhancement suggesting a cerebral infarct in the inferior posterior region of the left temporal lobe. Patient's hospital course was characterized by a marked improvement of alexia, especially of "kana" letters as compared with that of "kanji" characters. Dissociative improvement of alexia compared with agraphia in this case could be explained by the fact that the lesion was in close contact with the occipital lobe and that he also had pure alexia in the early stage.

Agraphia↗
PubMed1986

[The effect of cis-platinum (CDDP) on methotrexate-resistant choriocarcinoma cell line].

Cis-platinum (CDDP) was investigated in vitro and in vivo for its ability to inhibit the growth of Methotrexate (MTX)-resistant choriocarcinoma cell line (BeWo) and was compared with the effect of MTX and Actinomycin D (ACD). Each drug was added into medium (RPMI 1640 containing 10% FBS) for 1 hr. at the concentration of peak plasma level in clinical use (CDDP 7 X 10(-6)M, MTX 10(-6)M, and ACD 8 X 10(-8)M), or for 48 hrs. at one-tenth of the level. CDDP inhibited the cell growth to 40% of control at 7 X 10(-6)M for 1 hr., and 25% at 7 X 10(-7) M for 48 hrs. And ACD suppressed the cell growth to 10% at both 8 X 10(-8)M for 1 hr. and 8 X 10(-9)M for 48 hrs. But MTX did not inhibit the cell growth at 10(-6)M for 1 hr., and inhibited to 60% of control at 10(-7)M for 48 hrs. On the other hand, BeWo transplanted to athymic nude mice (CD-1(ICR) nu/nu) was treated with intraperitoneal injections of CDDP (1.4 mg/kg/day for 4 consecutive days in a week and repeated for 2 and 4 weeks), MTX (2mg/kg/day for 4 consecutive days in a week and repeated for 2 weeks), and ACD (90 micrograms/kg/day for 4 consecutive days in a week and repeated for 2 and 4 weeks). The suppression of the tumor growth was seen in CDDP-treated group (TRW/CRW = 6.5%) and ACD-treated group (TRW/CRW = 29%) after 2 courses of treatment, but no apparent suppression was shown in the MTX-treated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Protective effect of Na+ and K+ against inactivation of (Na+ + K+)-ATPase by high concentrations of 2-mercaptoethanol at high temperatures.

Purified dog kidney (Na+ + K+)-ATPase (EC 3.6.1.3) was inactivated with high concentrations of 2-mercaptoethanol at 50-55 degrees C. The inactivation was prevented by NaCl or KCl, with KCl being more effective than NaCl (the former ion being about one order more efficient under a typical set of experimental conditions). A disulfide bond in the beta-subunit of the enzyme protein was prevented from reductive cleavage by NaCl or KCl in accordance with protection of the enzyme activity. Choline chloride did not exert a significant protective effect over a similar concentration range. (Na+ + K+)-ATPase was also inactivated with high concentrations of 2-mercaptoethanol in the presence of low concentrations of dodecyl sulfate. This inactivation was also prevented by NaCl or KCl, with the latter being again more efficient than the former. These results indicate that Na+ and K+ bound to their respective ion-binding sites on the alpha-subunit exert a protective effect on a disulfide bond on the beta-subunit. This suggests some sort of interaction between the alpha- and the beta-subunits.

Animals↗
PubMed1985

Effects of arachidonic acid on the metabolism of eicosapentaenoic acid in washed human platelets.

We examined effects of arachidonic acid (AA) on eicosapentaenoic acid (EPA) metabolism in washed human platelets. Although human platelets had been considered to metabolize scarcely EPA, a simultaneous addition of EPA and AA to washed platelet suspensions stimulated markedly EPA metabolism. In addition, the stimulatory effect was more potent over the formation of thromboxane (TX) B3 than that of 12-hydroxy-5,8,10,14,17-eicosapentaenoic acid (HEPE). The stimulation by AA can be due to AA itself and/or AA metabolites. Indomethacin decreased the stimulatory effect of AA on the HEPE formation, suggesting that cyclooxygenase product(s) of AA stimulated the HEPE formation. Among the metabolites of AA investigated, prostaglandin (PG)G2 and 12-hydroperoxy-5,8,10,14-eicosatetraenoic acid had the stimulatory effect on both TXB2 and HEPE formations, whereas PGH2, PGD2, TXB2 and 12-hydroxy-5, 8,10,14-eicosatetraenoic acid were ineffective.

Arachidonic Acid↗
PubMed1985

Pattern-evoked cortical potentials and nuclear magnetic resonance imaging in total and partial agenesis of the corpus callosum.

We have examined two cases of agenesis of the corpus callosum without any associated abnormalities. They were accidentally detected in X-ray-computed tomography. Total agenesis of the corpus callosum could be differentiated by nuclear magnetic resonance imaging from partial agenesis. They had moderately depressed stereopsis. Visually evoked cortical potentials to pattern stimuli showed abnormal findings in binocular viewing, and VECP equi-potential maps were similar to those of normal controls.

Adult↗
PubMed1985

Evidence for existence of angiotensins I and II in mature renin granules from rat kidney cortex.

Renin granules were isolated by the combination of discontinuous and continuous Percoll density gradient centrifugation. The peak fraction containing the highest concentration of renin granules was found to contain the highest concentration of both angiotensin I and II immunoreactive substances. The identity of the immunoreactive peptides was further confirmed as angiotensin I and angiotensin II by high pressure liquid chromatography in reference to standard compounds. The coexistence of angiotensins I and II with renin indicates the formation of angiotensin II in renin granules. These findings clarify the mechanism of intracellular formation of angiotensin II as opposed to its formation in plasma and provide evidence against the internalization of angiotensin II, a hypothesis supported by the failure to detect angiotensin I in renin granules. Angiotensin II was increased by a low sodium diet while a high sodium diet did not affect its content.

Angiotensin I↗
PubMed1985

High concentrations of arachidonic acid induce platelet aggregation and serotonin release independent of prostaglandin endoperoxides and thromboxane A2.

We examined platelet aggregation and serotonin release, induced by less than 60 micro M arachidonic acid, using washed platelet suspensions in the absence of albumin. The concentration of arachidonic acid used did not cause platelet lysis. Platelet responses induced by less than 20 micro M arachidonic acid were inhibited by aspirin, whereas those induced by above 30 micro M arachidonic acid were not inhibited, even by both aspirin and 5,8,11,14-eicosatetraynoic acid. Although phosphatidic acid and 1,2-diacylglycerol increased after the addition of arachidonic acid in aspirin-treated platelets, the amounts were not parallel to platelet aggregation. Oleic, linoleic and linolenic acids also induced platelet responses, while palmitic, stearic and arachidic acids did not. EDTA, dibutyryl cyclic AMP, apyrase and creatine phosphate/creatine phosphokinase brought about almost the same effects in platelet responses induced by the unsaturated fatty acids, other than arachidonic acid, as those induced by 40 micro M arachidonic acid. These results suggest that the mechanism of the actions of more than 30 micro M arachidonic acid on platelets is the same as that of the other unsaturated fatty acids and is independent of prostaglandin endoperoxides, thromboxane A2 and, perhaps, phosphatidic acid and 1,2-diacylglycerol.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed1985

Lack of a disulfide bond in the large subunit of (Na, K)ATPase.

Subunit distribution of disulfide bonds in the dog kidney (Na, K)ATPase was examined. It was estimated that there were no disulfide bonds in the alpha subunit and possibly one in the beta subunit. The disulfide bond located in the beta subunit would be a good probe for elucidation of the role of the beta subunit. Our previous overestimation was presumably due to the phospholipid attached to the subunits.

Animals↗