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S Someya

Publications and source records attributed to S Someya.

At least 37 records · Page 2Linked to original sources
PubMed1982

A study of esterase--its application to biotransformation of midecamycin derivatives.

Esterases of intestinal mucosa and liver from human and rat were used to study the biotransformation of midecamycin derivatives. In the in vitro experiment with rat esterases, the 4"-acyl derivatives were more easily hydrolyzed than the 9-acyl derivatives. Among the 9-acyl esters, the highest hydrolytic activity was observed with butyrate. In the in vivo experiment, when the rats were administered with the derivatives of 4"-depropionylmidecamycin (M1) orally, comparatively more 9-acyl metabolites were excreted in the urine, but the amount of the 4"-acyl metabolites was very small. In the in vitro experiment with human esterases, the 9-acyl esters were hydrolyzed more easily than the 4"-acyl esters. Among the 9-acyl esters of M1, the highest hydrolytic activity was observed with butyrate. When the 9-acyl esters were administered to humans, the n-butyl ester was hydrolyzed faster than the acetyl ester. When the 9,4"-diacetyl ester was administered to humans, comparatively more 4"-acyl metabolites were excreted in the urine. These results suggest that the experiment with the use of these esterases is useful to estimate the biotransformation of midecamycin derivatives.

Animals↗
PubMed1982

Spleen cell transfer induces T cell-dependent granulomas in tuberculous nude mice.

After IV infection with an attenuated strain of Mycobacterium bovis BCG, athymic nude mice produced a few hepatic granulomas; most of the other foci of bacterial parasitization lacked obvious cellular reactions. Nude mice BCG-infected four weeks earlier received spleen cells from normal euthymic littermates. After transient splenomegaly which peaked at about two weeks, numerous hepatic granulomas appeared by four weeks and the number of viable BCG decreased. The development of hepatic granulomas required viable spleen cells and depended on the spleen cell dose and corresponded with positive footpad reactions. The effective population seemed to be T cells, since they were sensitive to treatment with anti-brain associated theta antigen serum (antiBAT) plus complement, and were found in nylon-wool passed fractions. After transfer with sensitized spleen cells, adoptive immunity was observed, provided that the recipient BCG-infected nude mice had been splenectomized before transfer. AntiBAT plus complement treatment of the sensitized spleen cells decreased the granuloma-producing as well as antimycobacterial capacity. When BCG-infected nude mice were irradiated with 500 r of gamma ray, granuloma production was decreased after immune spleen cell transfer. Co-transfer of immune spleen cells with normal nude mouse bone marrow cells to BCG-infected irradiated nude recipients restored the granuloma-forming ability.

Animals↗
PubMed1982

[Tissue distribution of 9, 3"-diacetylmidecamycin in the pregnant rat and in the rat following repeated administration (author's transl)].

The tissue distribution of 9, 3"-diacetylmidecamycin (MOM) was studied in the pregnant rats and in the rats following repeated administration. After oral administration of MOM (200 mg/kg) in the pregnant rats, the levels in the placenta and in the uterus were 2-3 times higher than that in the blood, however the levels in the amniotic fluid and in the fetus were 1/10-1/20 of the blood levels. After the third administration of MOM in the first day (30 mg/kg p.o./dose, 3 times/day, 4-hour interval), the levels in the liver, kidney, lungs, spleen, salivary glands and thymus were 1.5-12 times higher than that in the blood; the level in the muscle was almost equal to that in the blood; and the levels in the brain were 1/3-1/10 of the blood level. The tissue distribution patterns after repeated administrations were found to be similar to those of the first day administrations.

Animals↗
PubMed1982

Bacteriological evaluation of midecamycin acetate and its metabolites.

In vitro midecamycin acetate was shown to have broad spectrum of antibacterial activities similar to those of other macrolides (midecamycin, josamycin, 9-propionyl josamycin and 2'-ethylsuccinyl erythromycin), which include Gram-positive organisms, a part of Gram-negative organisms and anaerobes. Metabolites of midecamycin acetate also showed certain degree of antibacterial activities although they gave higher MIC values than midecamycin acetate. The antibacterial activities of midecamycin acetate were potentiated in the medium with pH 7 or pH 8 and little affected by inoculum size or addition of human serum into the medium. Both midecamycin acetate and its metabolites were found to have relatively high protein binding rates. In vivo therapeutic experiments in experimental infections in mice, midecamycin acetate was shown to be much superior to other drugs tested in the therapeutic efficacy against intraperitoneal infections caused by Staph. aureus, Strept. pyogenes, Strept. pneumoniae and Cl. perfringens. In infections transnasally induced by Strept. pneumoniae, midecamycin acetate showed therapeutic efficacy 2 or 5 times greater than that of josamycin or midecamycin, despite that MICs of midecamycin acetate were equal to josamycin or midecamycin. Moreover, midecamycin acetate showed high therapeutic efficacy for subcutaneous infections due to Staph. aureus, suggesting that it exerts pronounced antibacterial activities against not only systemic infections but also local infections.

Ampicillin↗
PubMed1981

Studies on the adequate composition of diphtheria and tetanus toxoids-with reference to the amounts of toxoids and aluminum adjuvant.

Immune response of man to tetanus and diphtheria-tetanus combined toxoids with different compositions was investigated, with special reference to the long-term immunity. Adsorbed tetanus toxoid with a potency of about 25 IU per human dose endowed a long-lasting immunity sufficient to prevent tetanus to the vaccines of various age groups, when administered in two doses, followed by a booster injection. Two doses of adsorbed diphtheria-tetanus combined toxoid with potencies of about 20 IU per dose for both components were sufficient to give immunity in infants against diphtheria and tetanus. However, a booster injection should be given within a year to endow a long-lasting immunity. In the case of booster immunization of children with a complete history of immunization against diphtheria and tetanus, a potent long-term immunity was endowed by a single injection of diphtheria-tetanus combined toxoid (plain) with 1 and 3.5 IU per dose, for diphtheria and tetanus components, respectively.

Adjuvants, Immunologic↗
PubMed1978

Progressive and fatal infection with attenuated Mycobacterium bovis (BCG) in nude mice.

Congenitally athymic nude mice (nu/nu) were infected intravenously with Mycobacterium bovis BCG Japanese strain under specified pathogen-free (SPF) or germ-free (GF) conditions. SPF euthymic litter mates (nu/+) serving as controls were found to tolerate the infection well, while SPF nu/nu mice following infection of 3 X 10(7) organisms died by week-36. Animals having received a very small dose (3 X 10(0) of organisms and their non-infected cage mates showed no evidence of infection at week 37 post-infection. Time-course observations carried out on SPF and GF nu/nu mice following infection with 10(5) or 10(6) organisms revealed that the number of organisms in the liver and spleen reached 10(6) to 10(7) viable units per organ at week 12 and this level was maintained for 50 weeks post-infection. Bacillary counts in the kidney and lung increased progressively and reached a level of 10(7) to 10(8) at the terminal stage of infection. In the liver, spleen and lymph nodes of nu/nu mice, granulomas were noted 12 weeks postinfection. The granulomas were composed of macrophages and accompanied by slight infiltration of lymphocytes, plasma cells and a small number of polymorphonuclear leucocytes. In later infection stages, small aggregations of pigmented macrophages packed with acid-fast bacilli were present in the liver, spleen and lymph nodes. Lesions with large foci of bacilli-laden macrophages developed progressively in the kidney, lung and subcutaneous and periosteal connective tissues. Periosteal granulomatous lesions, sometimes accompanied by exudation, intruded occasionally into the bone marrow, resulting in extensive granulomatous osteomyelities.

Animals↗
PubMed1977

Septicemic infection in nude mice caused by a virulent strain of Mycobacterium bovis.

Following i.v. infection with 2.3 to 2 X 10(6) viable organisms of Mycobacterium bovis strain Ravenel, congentitally athymic nude (nu/nu) mice of BALB/c background died earlier than their heterozygous (nu/+) counterparts, showing necrotic nodules in the heart and kidney with the involvement of liver and spleen. Pulmonary lesions in nu/nu mice, however, were less severe than those of dead nu/+ mice. In the reticuloendothelial organs of nu/nu mice, macrophages loaded numerous acid fast bacilli were transiently proliferated and later, necrotic-exudative lesions were produced without epithelioid granuloma formation, while necrotic lesions appeared at very early stage of infection in the other organs as well as adipose tissues. After thymocyte-reconstitution nu/nu mice were capable of developing epithelioid granulomas as seen in nu/+ mice, though having more numerous bacilli in granulomas than those of nu/+.

Animals↗