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Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 937 records · Page 52Linked to original sources

[Fertility study on ranitidine hydrochloride in rats].

A fertility study was carried out in Crj: CD (SD) rats orally administered ranitidine hydrochloride, a histamine H2-receptor antagonist, at dose levels of 50, 200 and 800 mg/kg/day in base weight. Male rats were treated from 60 days before mating until the completion of mating. Female rats were administered ranitidine hydrochloride from 14 days prior to mating up to day 7 of gestation. All pregnant females were sacrificed on day 20 of gestation and all fetuses were examined for abnormalities. Temporary salivation was noted in rats of both sexes given 800 mg/kg/day of ranitidine and in the male rat group given 200 mg/kg/day. No abnormal signs were seen in mating or fertility in the rats treated with ranitidine. No external, internal and skeletal anomalies attributable to ranitidine hydrochloride were observed in the fetuses. It was concluded that ranitidine hydrochloride has no harmful effect on mating, fertilization, implantation, or embryonic development.

Administration, Oral↗

Studies on biosynthesis of pentalenolactone. V isolation of deoxypentalenylglucuron.

Deoxypentalenylglucuron was isolated from the culture broths of three different strains, such as Streptomyces omiyaensis, S. albofaciens and S. viridifaciens. The structure of deoxypentalenylglucuron has been determined by 1H and 13C NMR, mass spectroscopy and by chemical correlation to be an oxidation product of pentalenene 1. Deoxypentalenylglucuron (1) has some antitumor activity against Sarcoma 180 in mice.

Animals↗

New antibiotic, isohematinic acid. I. Taxonomy of producing organism, fermentation and isolation.

New antibiotic, isohematinic acid, was found in the culture broth of an actinomycete strain SANK 61681, which was identified as a strain of Actinoplanes philippinesis. Fermentation of isohematinic acid was performed by conventional submerged culture in a 600-liter fermentor. Isolation of isohematinic acid was performed by adsorption of the antibiotic from the culture filtrate on a column of Diaion HP-20 followed by elution with aqueous acetone and extraction with ethyl acetate. Isohematinic acid was finally crystallized from hot methanol.

Actinomycetales↗

[Echocardiographic evaluation of cardiac involvement in patients with chronic alcoholism].

Since chronic alcoholics may accompany with asymmetric septal hypertrophy (ASH), the purpose of this study was to find the difference in cardiac function of such cases from the patients with hypertrophic cardiomyopathy. Ninety-seven alcoholic patients (59 non-cirrhotics and 38 cirrhotics) were examined by non-invasive methods including two-dimensional echocardiography and dye dilution method, and these data were compared with those of 16 normal subjects and 26 patients with hypertrophic cardiomyopathy. The results were as follows: Interventricular septal thickness of more than 12 mm was observed in 25.4% of the non-cirrhotics and 28.9% of the cirrhotics. Furthermore, ASH was present in 23.7% of the former and 18.4% of the latter, when ASH was defined as the septal to posterior wall ratio greater than 1.3 with the interventricular septal thickness greater than or equal to 12 mm. In 66.7% of the chronic alcoholics with ASH, hypertrophy was predominantly located in the septum, however 53.8% of the patients with hypertrophic cardiomyopathy had ASH in association with the thickened left ventricular posterior wall. In 21 chronic alcoholics with ASH, ejection indices such as ejection fraction and mean VCF were moderately increased, although scattered widely, as compared with those of the normal subjects. Latent reduced ventricular function compensated by sympathetic overactivity was postulated based on left ventricular performance maintained normally as indicated by a decrease of end-systolic wall stress. Several possible factors including hypertension, catecholamine and metabolic abnormalities were analyzed to explain the genesis of ASH in chronic alcoholics, but the true etiology remained unknown. In conclusion, ASH associated with chronic alcoholism is a type characteristic of alcoholic cardiomyopathy, and seems to belong to a clinical entity different from hypertrophic cardiomyopathy from a standpoint of clinical symptoms, age and the pattern of left ventricular hypertrophy.

Adolescent↗

Induction of murine tumors in adult mice by a combination of either avian sarcoma virus or human adenovirus and syngeneic mouse embryo cells.

Primary murine Rous sarcoma was produced in adult mice of seven strains, C57BL/6, DBA/2, BALB/c, C3H/He, CBAJ, AKR, and DDD, by s.c. inoculation of a mixture of 5 X 10(6) chicken tumor cells containing Schmidt-Ruppin Rous sarcoma virus and 9- to 12-day-old mouse embryo cells (MEC) (2 X 10(6) ) of the syngeneic strain. The sarcoma developed at the site of injection in almost all mice tested, but there were some differences in the latent period and the survival time among mouse strains. When the number of cells inoculated was reduced to 5 X 10(4) for chicken tumor cells induced by the Schmidt-Ruppin strain of Rous sarcoma virus (SR-CTC) and 2 X 10(4) for MEC, no tumor was produced in C3H/He mice. These tumors had strain specificity and the Schmidt-Ruppin strain of Rous sarcoma virus genome in masked form. The tumor at the site of injection originated in the embryo cells injected along with SR-CTC. This was confirmed by CBAT6/T6 marker chromosome analysis of the tumor cells of CBA mice induced with SR-CTC plus CBAT6/T6 MEC and also confirmed by transplantation of a C57BL/6 X C3H/He F1 tumor which had been induced with SR-CTC plus C3H/He or C57BL/6 MEC. Tumor induction in adult mouse by a mixture of virus and syngeneic 9- to 14-day-old embryo cells was tested for human adenovirus serotype 12 (Ad12) and simian virus 40. Primary Ad12 tumor was also induced in adult CBA, C3H/He, and DDD mice by 4 X 10(5 to 6) 50% tissue culture infective dose of Ad12 with 5 X 10(6) syngeneic embryo cells. This tumor contained Ad12 T-antigen-positive particles in cells. But in the case of simian virus 40, the tumor did not appear for about 300 days of observation.

Age Factors↗

[Clinical experience with cefotiam in otorhinolaryngologic infections].

Clinical studies of cefotiam (CTM), a new cephalosporin derivative, in otorhinolaryngological field were performed, and the results were summarized as follows. CTM was intravenously injected to 31 cases of otorhinolaryngological infections in daily dose of 1--4 g. Clinical efficacy was 33.3% in acute otitis media and chronic otitis media (acute exacerbation) (6 cases), 90% in acute tonsillitis (including peritonsillitis, peritonsillar abscess) (20 cases), 50% in acute pharyngitis (2 cases), 100% in acute sinusitis (2 cases) and 100% in epiglottis abscess (1 case), respectively. Bacteriological efficacy was 80% for beta-Streptococcus, 100% for K. pneumoniae, 50% for P. aeruginosa, and 85.7% for Peptococcus and Peptostreptococcus, respectively. No difference was observed in various daily doses for clinical efficacy. As for side effects and laboratory findings, eruption in 1 case, elevation of GOT in 1 case and elevation of GOT, GPT in 2 cases were observed. But, all of the cases were normalized after stoppage of administration or postadministration.

Adult↗

[Effect of BCG (Bacillus Calmette Guérin) sensitization on the generation of tumor specific killer T cells].

Effector cells of augmented resistance against a syngeneic MC-1 tumor in C57BL/6 mice sensitized with BCG were determined by Winn test, and the following results were obtained: Sensitization of mice with BCG (1.0 mg/mouse) augmented resistance against primary and secondary inoculation of MC-1 tumor. Peritoneal exudate cells of tumor-bearing mice showed a growth-inhibitory activity against MC-1 tumor in Winn test. Sensitization with BCG augmented such an activity of PEC. Augmented resistance was ascribed to a plastic dish-nonadherent, nylon wool column-nonadherent and Thy 1.2-positive cells.

Animals↗

[Intracardiac flow pattern in dilated cardiomyopathy studied with pulsed Doppler echocardiography].

Left ventricular (LV) flow dynamics were analyzed by pulsed Doppler echocardiography in patients (pts) with dilated cardiomyopathy (DCM). Subjects consisted of five normal controls, 27 pts with DCM, five with myocardial infarction and five with valvular heart disease. The equipment used was a two-dimensional echocardiograph ( Toshiba SSH- 11A ) coupled with a pulsed Doppler flowmeter ( Toshiba SDS-10A). The long-axis plane through the left ventricle was obtained from an apical transducer position and Doppler flow signals were recorded at the apex (point A), the middle portion (point B), the inflow portion (point C), the portion near the mid-IVS (point D) and the outflow portion (point E) of the left ventricle, respectively. Left ventriculography was performed in all subjects, and ejection fraction (EF), the ratio of the short-axis to long-axis distance in end-diastole, percent shortening of the long axis and percent shortening of the short axis of the left ventricle were measured. Doppler signals of an ejection flow were recorded at points A, B, D and E in the normal controls, while in 27 pts with DCM Doppler signals of an ejection flow were detected only in two pts (7%) at the point A, in three pts (11%) at the point B, 16 pts (59%) at the point D and 27 pts (100%) at the point E. Twelve pts (44%) had abnormal Doppler signals with wide-band spectral pattern at the point C in systole. Toward flow signals in early diastole were recorded at the points A, B, C and D in the normal controls, while in pts with DCM the signals were visualized in only three pts (11%) at the point A, in 27 pts (100%) at the points B and C, and 10 pts (37%) at the point D. EF in pts with DCM was lower than that of the normal controls (36 +/- 11 vs 65 +/- 5%, p less than 0.005). The ratio of the short-axis to long-axis distance of the left ventricle was higher in pts with DCM compared with that of the normal controls (0.82 +/- 0.09 vs 0.60 +/- 0.02, p less than 0.005). Percent shortening of the long axis and the short axis was depressed in pts with DCM compared with the normal controls (11 +/- 5 vs 21 +/- 4%, p less than 0.02 and 15 +/- 6 vs 34 +/- 3%, p less than 0.001, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Induction of angiogenic tumors in the duodenum of female Donryu rats by continuous oral administration of N-isobutyl-N-nitrosourea.

Four groups of female Donryu rats were continuously given 400, 200, 100 or 0 ppm N-isobutyl-N-nitrosourea (iso-BNU) in their drinking water, and were examined for the development of tumors. The incidence of digestive tract tumors was 25/28 (89%), 14/24 (58%), 6/25 (24%) and 0/17 (0%), in the 400, 200, 100 and 0 ppm groups, respectively. The predominant type of digestive tract tumor was angiogenic, and a few were of the epithelial type. A dose-effect relationship was clearly demonstrated not only in the incidence of digestive tract tumors but also in the average survival period of rats with these tumors.

Administration, Oral↗

Temperature-induced transitions of porcine intestinal brush border membranes.

Thermotropic transitions of the membrane components in porcine intestinal brush border membranes were studied by means of fluorimetry using a fluorogenic thiol reagent, N-[7-dimethylamino-4-methylcoumarinyl]maleimide (DACM), and a lipophilic fluorescent probe, 1,6-diphenyl-1,3,5-hexatriene (DPH). 1. The reactivity of the sulfhydryl groups of the membrane proteins with DACM was dependent on temperature, with a transition point at about 33 degrees C. A conspicuous transition was also observed in the relation between temperature and the fluorescence intensity of DACM-labeled membranes at 35 degrees C. 2. Temperature dependence profiles of the solubilization of DPH in the membranes and of the fluorescence polarization of DPH-membrane complex suggested that the phase transition of the lipid from gel to liquid-crystalline state occurs over a temperature range of 30 to 35 degrees C. 3. Efficient fluorescence energy transfer was observed from tryptophan residues of the membrane proteins to DPH located in the lipid phase of the membranes, and its efficiency was extremely enhanced, dependent on temperature, above 35 degrees C. The intensity of the tryptophan fluorescence of the membrane proteins decreased with increasing temperature and a discontinuity was observed at about 33 degrees C. Based on these results, it may be concluded that there are co-operative interactions between proteins and lipids in the membranes and that the temperature-induced conformational changes of the membrane proteins are closely related to the dynamics of the hydrocarbon cores of the lipid.

Animals↗

Formation of Hassall's corpuscles in vitro by the thymic epithelial cell line IT-26R21 of the rat.

In the monolayer of an established epithelial cell line from the rat thymus, IT-26R21, characteristic cell aggregates quite similar to Hassall's corpuscles were formed. These aggregates were examined by light and electron microscopy, and immunohistochemically. Their interpretation as Hassall's corpuscles is based n the following observations: (1) The aggregates are formed in the monolayer of cells that greatly resemble medullary epithelial cells of the thymus. (2) They consist of flattened epithelial cells in a concentric pattern with one or ore degenerating cells in the center. (3) Loss of microvilli suggests that these cells are keratinizing. (4) The aggregates show strongly positive reactions in immunofluorescent staining with antikeratin and antiprekeratin. When Hassall's corpuscles increase in size, cellular proliferation is somewhat suppressed. Both in vivo and in vitro, they may be interpreted as an expression of a changing growth pattern in confined spaces and thus seem to have little immunological function.

Animals↗