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Biomedical subjects

I Wada

Publications and source records attributed to I Wada.

125 records · Page 7Linked to original sources
PubMed1982

A unique change of steroid metabolism in rat liver microsomes induced with highly toxic polychlorinated biphenyl(PCB) and polychlorinated dibenzofuran(PCDF).

Pretreatments of rats with the highly toxic compounds such as 3,4,5,3',4'-pentachlorobiphenyl(PenCB), and 2,3,7,8-tetrachloro(TCDF) and 2,3,4,7,8-pentachlorodibenzofuran(PenCDF), which are potent 3-methylcholanthrene(MC)-type inducers, increased selectively 7 alpha-hydroxylation, but strongly suppressed 2 alpha-, 6 beta- and 16 alpha-hydroxylations as well as 5 alpha-reduction of progesterone and testosterone in the liver microsomes. This unique change in the metabolic pattern was accompanied by a marked decrease in total metabolism of both steroids and appeared to correlate apparently with their toxic potency. This kind of change was not shown by pretreatments with not only MC itself but also the phenobarbital-type(2,4,5,2',4',5'-hexachlorobiphenyl) and the mixed type PCBs(Kanechlor 400, a PCB mixture with 48% chlorine content), all of which possess only a low acute toxicity. The metabolic change produced by 3,4,5,3',4'-PenCB, 2,3,7,8-TCDF and 2,3,4,7,8-PenCDF might not be due to their stimulatory or inhibitory effects, because when added to the incubation mixture 3,4,5,3',4'-PenCB did not change the metabolic pattern with MC-microsomes to that with 3,4,5,3',4'-PenCB-microsomes. Furthermore, either 2,3,7,8-TCDF or 2,3,4,7,8-PenCDF gave similar metabolic pattern whereas their residual levels in the liver were greatly different from each other at the time of sacrifice. These results suggest that this kind of unique change of the steroid metabolism produced by highly toxic PCBs and PCDFs may be responsible, at least in part, for the endocrine symptoms caused by these compounds via disturbance of steroid homeostasis.

Animals↗
PubMed1982

Effects of local anesthetics on monoamine oxidase, and their membrane effects.

The effects of various local anesthetics on rat brain and liver monoamine oxidase (MAO) and their antihemolytic and local anesthetic effects were studied. All local anesthetics tested at 1 x 10(-7) M to 1 x 10(-3) M inhibited MAO activity in rat liver mitochondria with 5-hydroxytryptamine (5-HT) as substrate. The order of potency was tetracaine>procaine>dibucaine>lidocaine>prilocaine. Tetracaine and procaine inhibited 5-HT oxidation much more than beta-phenylethylamine (PEA) oxidation. Dibucaine inhibited PEA oxidation as much as 5-HT oxidation. Inhibition of MAO by local anesthetics other than dibucaine was reversible. Tetracaine and procaine inhibited 5-HT oxidation competitively, whereas dibucaine inhibited it non-competitively. Antihemolytic effects were observed with dibucaine and tetracaine at concentrations of 6 x 10(-5) M and 1 x 10(-4), respectively. The order of surface anesthetic potencies was dibucaine>tetracaine>prilocaine>lidocaine>procaine. These results suggest that the inhibition of MAO activities by local anesthetics depends on both electrostatic and hydrophobic interactions between these drugs and enzyme-associated phospholipids or the hydrophobic regions of proteins.

Anesthetics, Local↗
PubMed1979

Histopathological study on effects of potassium aspartate on the hypothalamus of rats.

Rats of various ages were treated orally or intraperitoneally with potassium aspartate. The dose required to induce hypothalamic lesion varied considerably by the age of animals and route of administration. Additional experiment, in which the animals were orally treated three times a day with potassium aspartate in dose levels between the maximum safety dose and minimum lesion-producing dose in the preceding single dose study, revealed no hypothalamic lesion at all in any animals of each age group. In this condition, the maximum safety dose was 3--5 times as large as that in single dosage administration experiment. Regarding the safety evaluation of potassium aspartate preparations, brief discussions on some points in extrapolation of the results of the present experimental study to the clinical use were made.

Administration, Oral↗
PubMed1975

[Pharmacological study of 9 alpha-fluoro-11 beta, 17, 21-trihydroxy-16 beta-methylpregna-1, 4-diene-3,20-dione-17-benzoate (betamethasone-17-benzoate, MS-1112), a local anti-inflammatory agent. (1). Its anti-inflammatory and other pharmacological properties].

The anti-inflammatory activity and the other pharmacological properties of MS-1112, a new steroid compound, were examined and compared with other glucocorticoid analogues such as hydrocortisone acetate (Hydr), betamethasone 17-valerate (Val) and dexamethasone (Dexa). Systemically administered MS-1112 and glucocorticoids had a significant effect in inhibiting rat paw edema induced by various phlogistic stimulations and increasing vascular permeabilities and granuloma formation by cotton pellet or granuloma pouch. The order of those inhibiting activity was, in general, Dexa greater than MS-1112 greater than Val greater than Hydr. Concomitantly, Xthymolysis and adrenal weight suppression and reduced rate of body weight gain after multiple systemical administration were also observed. Locally administered MS-1112 caused an inhibiting activity, without systemic side-effects. This activity was approximately 3 to 5 times more potent than that of Dexa in rat carrageenin paw edema and cotton pellet granuloma. MS-1112 was less active than Dexa in glycogen liver deposition activity and in the depression of plasma level of corticosterone but more active than Val and Hydr. In the dose administered, MS-1112 had neither androgenic and anabolic nor estrogenic and anti-estrogenic activity. From this data, it concluded that MS-1112 is a very potent agent applicable regarding permeability and retention of steroids in a local site.

Administration, Topical↗
PubMedDate not supplied

Intraductal ultrasonography of traumatic neuroma of the bile duct.

We report a case of a 70-year-old female with traumatic neuroma of the bile duct. Transpapillary intraductal ultrasonography showed a cystic duct stump, from which a smooth and homogeneous hypoechoic mass arose; the adjacent bile duct wall had a normal structure. Intraductal ultrasonography is useful for distinguishing traumatic neuroma from bile duct carcinoma.

Aged↗
PubMedDate not supplied

Ultrasound biomicroscopic corneal thickness measurement for corneal thickness mapping.

Digitalized ultrasound biomicroscopic measurements of vertical cross sections from a 5 mm diameter area of the central cornea of normal and morbid eyes were used to create a computerized corneal thickness map. Mean corneal thickness in normal eyes was 0.503 +/- 0.027 mm; the coefficient of variation, an index of reproducibility, was < 10% in all eyes.

Adult↗
PubMedDate not supplied

Analysis of nucleotide sequences of hepatitis C virus isolates from husband-wife pairs.

To identify the route of hepatitis C virus (HCV) transmission, we investigated the sexual transmission of HCV by examining HCV markers among spouses of patients with chronic liver disease (CLD) due to HCV. Of 83 spouses, 14 (16.9%) had elevated serum aspartate aminotransferase or alanine aminotransferase, 20 (24.1%) had detectable anti-HCV antibodies, and 17 (20.5%) had measurable HCV-RNA in serum. However, the seropositivity rate of anti-HCV antibodies (24.1%) of patients' spouses was not significantly higher than that (15.4-27.5%) of an unselected population in the same district. Ten patient-spouse pairs underwent nucleotide sequence analysis of the HCV core and envelope genes. Overall the sequence homology of 10 couples (91.1%) was not significantly higher than that of 10 randomly chosen unrelated pairs (88.2%). As reported earlier, in an age and sex matched case-control study of HCV transmission, a history of surgery is a prominent HCV risk factor. These results suggest that sexual transmission of HCV is rare.

Adult↗