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Y Akaike

Publications and source records attributed to Y Akaike.

27 records · Page 2Linked to original sources
PubMed1982

A new class of nitrosoureas. 4. Synthesis and antitumor activity of disaccharide derivatives of 3,3-disubstituted 1-(2-chloroethyl)-1-nitrosoureas.

A series of 33 N-(2-chloroethyl)-N-nitrosocarbamoyl derivatives of N-substituted glycosylamines has been prepared and tested for antitumor activities. The compounds were obtained by reaction of glycosylamines with isocyanate, followed by nitrosation with N2O4. Structure-activity relationships of these trisubstituted nitrosoureas were investigated by varying the N-substituents and disaccharide groups and by comparing them with the corresponding disubstituted analogues. A large number of the nitrosoureas bearing a maltosyl group exhibited strong antitumor activities against leukemia L1210 and Ehrlich ascites carcinoma, and 60-day survivors against leukemia L1210 were found at the optimal dose for these derivatives. In contrast, the lactosyl and the melibiosyl derivatives were almost inactive. The most interesting compound in this series, the 3-isobutyl-3-maltosyl derivative (37), was tested against leukemia L1210 by single and multiple treatment. Its therapeutic ratio (96.3) obtained by multiple treatment is 3 times larger than that (31.5) obtained by single treatment, suggesting a possible clinical utility of 37 by multiple treatment. The favorable effect of a maltosyl moiety in this class of compounds is discussed.

Animals↗
PubMed1982

Effect of 1-(2-chloroethyl)-3-isobutyl-3-(beta-maltosyl)-1-nitrosourea on experimental tumors.

The antitumor activity of 1-(2-chloroethyl)-3-isobutyl-3-(beta-maltosyl)-1-nitrosourea (TA-077), a novel water-soluble nitrosourea derivative, against leukemia L1210, Ehrlich carcinoma, sarcoma 180, Lewis lung carcinoma, Yoshida sarcoma, rat ascites hepatomas and Walker 256 carcinosarcoma was examined and compared with those of 3 reference nitrosourea antitumor agents, 1-(2-chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea, 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitrosourea hydrochloride and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea. TA-077 exhibited a broad antitumor spectrum against the above tumors. Among these 4 nitrosoureas, TA-077 produced the best therapeutic ratios (OD/ILS30) against leukemia L1210, irrespective of the administration route and schedule employed. The ratio obtained by consecutive treatment (ip) was superior to that by single administration, a unique characteristic of this novel nitrosourea agent. The inhibitory effect of TA-077 on the growth of non-syngenic tumors (solid form) was also significant in all administration routes employed (ip, iv and po). Furthermore, TA-077 showed a marked life-prolonging effect on both early and advanced forms of Lewis lung carcinoma.

Animals↗
PubMed1981

Production of heat-stable enterotoxic component by Escherichia coli strains enteropathogenic for swine.

Forty-nine strains of Escherichia coli isolated from piglets with or without neonatal diarrhea were all negative for both classical heat-labile and heat-stable enterotoxins when examined by the 18-hour rabbit ileal loop test with culture supernatants, the mouse Y1 adrenal cell test, and the infant mouse test. Of them, seven strains from diarrhea were positive only when tested in porcine ileal loops challenged with living bacterial cell suspensions or culture supernatants. The enterotoxic component produced by them was resistant to heating at 80 degrees C for 20 minutes. It presented a rapid onset of action with a long duration, although the amount of accumulated fluid in the porcine ileal loops was small. These porcine strains of E. coli which has been positive only for the porcine ileal loop test were designated "ST pig loop" or "STpl" strains.

Animals↗
PubMedDate not supplied

Necrotizing lymphadenitis: a review of clinicopathological, immunohistochemical and ultrastructural studies.

Necrotizing lymphadenitis (NEL) has been reported to be a reactive process described under differing terminology by Fujimoto et al. (1972), Kikuchi (1972), Wakasa et al. (1973) and other Japanese pathologists. Recently, this type of lymphadenitis has also been reported in America and Europe. In Japan, NEL is observed more frequently in the northern area, however, no characteristic seasonal occurrence has been noted. The disease affects young females more than males, particularly from the third and fourth decades onwards. Common cold-like symptoms, lymphadenopathy of the cervical region and leukopenia are characteristic clinical findings in the early stages. Morphological features of the involved lymph nodes include the presence of numerous immunoblasts, histiocytes and macrophages, the latter with phagocytized nuclear debris derived from degenerated lymphocytes. However, granulocytes are generally absent. Tubular inclusions are observed ultrastructurally. Immunohistochemical studies of peripheral blood using monoclonal antibodies have revealed that the helper/suppressor (Leu 3a/2a) ratio increases gradually with the clinical course because of a decrease in Leu 2a + cells. The pathogenesis of NEL is uncertain, but it has been speculated that there is cytolytic infection of lymphocytes by a virus or other organism, accompanied by secondary blastic transformation of suppressor T-lymphocytes.

Diagnosis, Differential↗