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Biomedical subjects

Y Wada

Publications and source records attributed to Y Wada.

At least 901 records · Page 50Linked to original sources
PubMed1988

[Ultrastructural observation of human papillomavirus particles in the uterine cervix intraepithelial neoplasia].

Using transmission electron microscopy (TEM), twenty two cases of an intraepithelial lesion in the uterine cervix have been examined for the presence of human papillomavirus (HPV) particles. In 21 of these cases (95%), HPV particles were detected in the nucleus, and in 5 cases, in the cytoplasm. The distribution of the intranuclear HPV particles was classified into 4 types. In only 2 cases did the exhibited particles show a geometrical crystalline array (type I). In most cases, the exhibited particles were either seen to show an aggregate non-crystalline array (type II) or were concentrated around the chromatin (type III). Some cases also were found to show particles that were scattered sporadically in the nucleoplasm (type IV).

Cytoplasm↗
PubMed1988

[Effects of androgen on 17 beta-estradiol and progesterone secretion by cultured human granulosa cells].

Human granulosa-luteal cells obtained from dominant preovulatory follicles at the time of oocyte retrieval for in vitro fertilization (about 10 h after the peak of the endogenous LH surge) produced large quantities of progesterone (P) (8.7 pg/cell/first 2 days) in a monolayer culture. Although basal production of estradiol (E2) in these granulosa-luteal cells was restricted to small quantities, a marked increase in E2 production occurred in the presence of testosterone (T) (10(-6) M) as aromatizable substrate. The non-aromatizable androgen, 5 alpha-dihydrotestosterone (DHT) (10(-7) M, 10(-6) M) slightly enhanced E2 production in these granulosa-luteal cells and it did not inhibit T aromatization. In contrast, DHT did not increase E2 production in cultured granulosa cells obtained from follicles 2 approximately 5 days before the LH surge. Thus, the response of granulosa cells to exogenous androgen seems to vary at different stages of cell differentiation. Neither T nor DHT elicited significant changes in the production of P by granulosa-luteal cells obtained from preovulatory follicles during the LH surge. However, T (10(-6) M) suppressed hCG-stimulated P production in these cells. The results suggest that androgen enhances the estrogen biosynthesis of granulosa-luteal cells obtained from preovulatory follicles during the LH surge not only by acting as substrate for aromatization but also by participating in some process of estrogen synthesis. Further, it is suggested that androgen has a negative effect on P biosynthesis in these cells.

Androgens↗
PubMed1987

Vacuolar ion channel of the yeast, Saccharomyces cerevisiae.

Ionic flux is most likely to regulate the chemiosmotic potential differences across vacuolysosomal membranes in animal, plant, and fungal cells. We found a membrane potential-dependent cation channel in yeast vacuolar membrane and characterized its several features by an electrophysiological method using artificial planar bilayer membranes incorporated with isolated yeast vacuolar membrane vesicles. This ion channel conducts K+ (single channel conductance, 435 pS in 0.3 M KCl) and several other monovalent cations (Cs+, Na+, and Li+) with broad selectivity, but does not conduct Cl-. The opening of this channel is regulated by the membrane potential and the presence of calcium ion on the cytoplasmic face. These characteristics suggested that the vacuolar cation channel functions as one of essential components for formation and regulation of the chemical and electrical potential differences across the vacuolar membrane.

Calcium↗
PubMed1987

Cloning and sequence of cDNA encoding a peptide C-terminal alpha-amidating enzyme from Xenopus laevis.

The C-terminal alpha-amide formation of the peptides is one of the most important events of prohormone processing. We have recently isolated an alpha-amidating enzyme, AE-I, from Xenopus laevis skin, which is the only enzyme ever purified to homogeneity. In this study, we report cloning and sequence of cDNA encoding AE-I. Our results indicate that enzyme AE-I is initially synthesized as a precursor with 400 amino acid residues, which is further processed to the mature enzyme consisting of 344 residues. Preliminary expression in E. coli of the cDNA corresponding to AE-I was found to produce an enzyme with appreciable alpha-amidating activity.

Amino Acid Sequence↗
PubMed1987

Identification of glutarylcarnitine in glutaric aciduria type 1 by carboxylic acid analyzer with an ODS reverse-phase column.

A technique for the identification of glutarylcarnitine in urine from a patient with glutaric aciduria type 1 is described. The patient's urine sample was partially purified using an anion exchange column and analyzed by a carboxylic acid analyzer fitted with an ODS reverse-phase column. The chromatogram of the patient's urine sample revealed 3 different peaks, which corresponded respectively to those of carnitine with amino acids, acetylcarnitine and glutarylcarnitine. Following hydrolysis of the sample, the chromatogram had no peaks of acetylcarnitine and glutarylcarnitine but had remarkably amplified peaks of carnitine, acetic acid and glutaric acid. The eluent fraction of glutarylcarnitine from the non-hydrolyzed sample was hydrolyzed and analyzed again. It no longer had the glutarylcarnitine peak on the chromatogram, but had only two separate peaks of carnitine and glutaric acid. This technique simplifies the identification of glutarylcarnitine, in that it requires only removal of organic acids for preparation of samples, and does not require radioisotope or mass spectrometry.

Acetylcarnitine↗
PubMed1987

Adult-onset spinocerebellar syndrome with idiopathic vitamin E deficiency.

A 62-year-old man and his maternal uncle had a selective vitamin E deficiency without generalized fat malabsorption. A progressive neurological disorder comprising ataxia, areflexia, and loss of proprioception developed in their sixth and seventh decades. The vitamin E deficiency is thought to be due to abnormally accelerated utilization, excretion, or degradation of the vitamin. This adult-onset spinocerebellar syndrome is due to vitamin E deficiency not caused by malabsorption.

Age Factors↗