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Biomedical subjects

T Tashiro

Publications and source records attributed to T Tashiro.

At least 415 records · Page 23Linked to original sources
PubMed1981

Relation of conformation to antitumor activity of platinum(II) complexes of 1,2-cyclohexanediamine and 2-(aminomethyl)cyclohexylamine isomers against leukemia P388.

The antitumor activity of various platinum(II) complexes of 1,2-cyclohexanediamine and 2-(aminomethyl)cyclohexylamine isomers against leukemia P388 was evaluated by means of the platinum analogue study protocol recommended by the National Cancer Institute. For the former complexes, trans isomers are more efficacious than the corresponding cis isomers. For the latter complexes, cis isomers seem to be somewhat more active than trans isomers. 2-(Aminomethyl)cyclohexylamine platinum complexes exhibited higher activity than 1,2-cyclohexanediamine complexes in this tumor system. These findings encouraged us to determine the structural differences between 1,2-cyclohexanediamine and 2-(aminomethyl)cyclohexylamine complexes. Their structures of platinum complexes were elucidated from circular dichroism and 13C NMR spectral analyses, and it has been concluded that the cyclohexane ring of cis-1,2-cyclohexanediamine is nearly perpendicular to the chelate ring, while both rings of trans-1,2-cyclohexanediamine and trans-2-(aminomethyl)cyclohexylamine complexes lie in a common plane. The structure of cis-2-(aminomethyl)cyclohexylamine complexes is flexible, and the cyclohexane ring is not perpendicular to the chelate ring. The coplanarity of trans isomers and the flexibility of cis-2-(aminomethyl)cyclohexylamine complexes allow them easy approach to the target DNA. However, the perpendicular ring of cis-1,2-cyclohexanediamine complexes would prevent their interactions with dna molecules due to the steric hindrance.

Animals↗
PubMed1980

[A case of 17 alpha-hydroxylase deficiency with male pseudohermaphroditism (author's transl)].

A 17-year-old youth was admitted because of proteinuria noted during a routine examination at his high school. His parents and three siblings were living in good health and there was no familial tendency to hypertension and no consanguinity. On physical examination, he was 161cm in height and weighed 43Kg, and his facial expression was female-like. Neither webbed neck nor cubitus valgus was noticed. Severe hypertension ranging from 190/120 to 230/130 was noted. No axillary or pubic hair was present, and the breasts were prepubertal in size. A gynecological examination revealed the presence of labia and vagina. Laboratory findings on admission were summarized as follows: The urine gave a (-)--(+) test for protein, renal function was revealed as normal, serum potassium ranged from 3.2 to 4.2mEq/L, the specimen of arterial blood showed pH 7.421, and an electrocardiogram revealed left ventricular hypertrophy and U wave changes in leads V2, V3, V4. X-rays showed a bone age of 12 years, and chromosome analysis revealed a karyo type of 46,XY. Endocrinological studies confirming the presence of a 17 alpha-hydroxylase deficiency were summarized as follows: 1) Plasma ACTH was markedly elevated. 2) Plasma renin activity was markedly suppressed showing no response to exercise. 3) Plasma progesteron, plasma DOC and plasma-corticosteron were extremely high. In contrast, plasma aldosteron was extremely low. 4) Plasma 17 alpha-OH progesteron and plasma cortisol were markedly reduced. Urinary excretion of 17-OHCS was extremely low. 5) Plasma testosteron and urinary 17-KS were markedly reduced. The patient was treated with 2mg then 1mg dexamethasone daily for half a year. After one month of therapy, the blood pressure was down to 160/100mmHg, and the serum potassium had risen from 3.2mEq/liter to 5.6mEq/liter. Plasma progesteron, plasma DOC, plasma corticosteron and plasma ACTH decreased to a normal level. Subsequently suppressed plasma renin activity elevated to a normal value. After 6 weeks of this treatment, a laparotomy was performed. Ovaries and uterus were absent, but bilateral testes were found at the external inguinal ring. Microscopic examination of the testis showed Sertoli cell adenoma. We have reported here a case of 17 alpha-hydroxylase deficiency with male pseudohermaphoriditism and discussed the endocrinological data and histological findings of the testis.

Adolescent↗
PubMed1980

Antitumor activity of platinum(II) complexes of 1,2-diamino-cyclohexane isomers.

Dichloro, dibromo, oxalato, malonato, dinitrato, sulfato and mono and bis-(D-glucuronato) platinum(II) complexes of 1,2-diaminocyclohexane (dach) isomers were prepared and tested on L1210 mouse leukemia employing the NCI protocol for evaluation of Pt analogs. A large number of long-term survivors were observed with certain analogs, though the therapeutic indices (optimal dose/minimum effective dose) were not large. Among the analogs tested, the oxalato, malonato, dinitrato and mono-(D-glucuronato) Pt(II) complexes of trans-1,2-diaminocyclohexane were found to be particularly effective. The glucuronato Pt complexes appear to be promising candidates for clinical trial since they have the highest solubility in water.

Animals↗
PubMed1979

Isolation of synaptosomal plasma membranes from cholinergic nerve terminals and a comparison of their proteins with those of synaptic vesicles.

Plasma membranes were purified from purely cholinergic nerve endings (synaptosomes) isolated from the electric organ of Torpedo marmorata. Synaptosomes were lysed, membranes recovered and further separated by density gradient centrifugation. A fraction was obtained enriched in 5'-nucleotidase, Na+, K+-activated ATPase and acetylcholine esterase. Morphological examination showed abundant membrane fragments of the size range of synaptosomes and few of vesicle size. The fraction has a characteristic protein composition upon gel electrophoresis. Five reproducible major bands with apparent Mr of 100000, 75000, 52000, 42000 and 35000--33000 are found. A gel-electrophoretic comparison with proteins from synaptic vesicles from the same source (major bands Mr 160000, 147000, 34000 and 25000) was made. Comigration of major bands was detected in one-dimensional gel electrophoresis with the 42000-Mr, 35000--33000-Mr and 34000-Mr components. Upon two-dimensional gel electrophoresis the 42000-Mr component comigrates with a similar component in vesicles, recently characterized as actin; the other components are different. The presence of tubulin-like polypeptides is unlikely. Beside actin, all major vesicle proteins are often detected in small amounts in the plasma membrane preparation. It cannot be decided if they result from fused or contaminating vesicle membranes, but since they are essentially absent in some preparations, it seems that the plasma membrane does not contain vesicle proteins.

Animals↗
PubMed1979

Antitumor activity of norditerpenoid dilactones in Podocarpus plants: structure-activity relationship on in vitro cytotoxicity against Yoshida sarcoma.

The in vitro cytotoxicity of norditerpenoid dilactones isolated from Podocarpus plants was determined against cultured Yoshida sarcoma cells. The dilactones involved 15 natural lactones as well as their derivatives, which include appropriate modifications necessary to the estimation of the structure-activity relationship. The unsaturated system on the B/C ring portion, the dienolide or the epoxyenolide moiety, is essential for the activity, but the gamma-lactone group on the A/B ring portion is not. Other oxygenated substituents on the skeletal carbons, such as hydroxyl, acyloxyl, or epoxide group, also show some significant effect.

Animals↗