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Biomedical subjects

T Yasui

Publications and source records attributed to T Yasui.

At least 253 records · Page 14Linked to original sources
PubMed1987

Effects of atrial natriuretic peptide on renal function and renin release in the isolated perfused rat kidney.

The effects of synthetic atrial natriuretic peptide (ANP) on the renal hemodynamics, glomerular filtration rate (GFR), fluid and electrolyte excretion and renin release were studied in the isolated perfused rat kidney (IPK). When 10(-9) mol of ANP was administered in 75 ml of perfusate, the renal vascular resistance (RVR) was transiently decreased for 3 to 5 min, thereafter increased for 30 min and then tended to return to the control level. ANP increased the GFR (0.55 +/- 0.08 to 0.71 +/- 0.07 ml/min), urine flow (UV) (0.018 +/- 0.002 to 0.194 +/- 0.028 ml/min), absolute Na excretion (UNaV) (1.83 +/- 0.03 to 17.93 +/- 2.71 microEq/min) and absolute K excretion (UKV) (0.67 +/- 0.13 to 2.33 +/- 0.18 microEq/min). The addition of indomethacin or mefenamic acid to the perfusate before the administration of ANP exerted no influence on any of the effects of ANP. Renin release was inhibited by approximately 50% compared to the ANP-free control group. With the administration of ANP, UV and UNaV reached a peak 15-20 min after the GFR reached a peak and remained elevated after the GFR fell below the control level. These findings suggest that 10(-9) mol of ANP causes natriuresis and renin suppression in the IPK, and that the natriuresis is prostaglandin-independent and cannot be explained only by an increase in GFR.

Animals↗
PubMed1987

[Expression of Thomsen-Friedenreich antigen (T-Ag) in gynecologic cancer tissues].

The expression of Thomsen-Friedenreich antigen (T-Ag), the precursor of MN blood group antigen, was studied by the ABC method with Arachys Hypogaea lectin (PNA) and the relationship of the results to the histology and clinical behavior of primary gynecologic cancers were examined. The results were as follows: 1. In cervical squamous cell tumors, the incidence of the expression of T-Ag in invasive cancers (52.9%, 37/70) was significantly higher (p less than 0.05) than that in intraepithelial tumors (28.6%, 8/28). No cryptic T-Ag(-) tissue was found in intraepithelial tumors or microinvasive cancers. 2. In squamous cell carcinomas of the cervix, the incidence of cryptic T-Ag(-) tissue was high (36.4%, 4/11) in tissue of the small cell non-keratinizing type, the most undifferentiated type, whereas it was not found in 5 cases of well-differentiated keratinizing carcinoma examined. 3. In stage Ib and II cervical cancers, no relationship was recognized between the expression of T-Ag in primary lesion and extension to the parametrium or the pelvic lymph nodes. 4. The incidence of T-Ag(+) tissue in adenocarcinomas of the uterine cervix (62.5%, 5/8), the endometrium (91.7%, 11/12), and the ovarian (80%, 8/10) was higher than that in squamous cell carcinoma of the uterine cervix (52.5%, 32/61). 5. In endometrial cancers, no relationship was recognized between the expression of T-Ag and hormone receptor status.

Adenocarcinoma↗
PubMed1986

Effect of cutting the zona pellucida on the pronuclear transplantation in the mouse.

A new and reliable pronuclear transplantation procedure for the mouse egg has been developed by McGrath and Solter ('83). To overcome the technical difficulties of such a procedure, especially in uniformly preparing enucleation pipettes and in reducing damages during micromanipulation, we have examined the effect of cutting the zona pellucida of the eggs. By making a slit in the zona of an egg, the time for pipetting and exchange of pronuclei between eggs was shortened because the sharp tip of the pipette was not necessary. Although the proportion of pregnant recipients and young obtained after transfer of pronuclear transplanted eggs cultured for 1 day or 3 days was quite low, it was significantly increased (70% for pregnancy rate and 32% for the young) following transfer of eggs cultured for 4 days. These values were comparable with those after transfer of unoperated eggs cultured to morulae and blastocysts.

Animals↗
PubMed1986

Hazardous effects due to alkaline button battery ingestion: an experimental study.

This study was performed to clarify the mechanism and extent of mucosal injury following button battery ingestion. After surgical implantation of several commercially available button batteries in the stomach or appendix of rats, battery voltage, mucosal pH, and histopathologic change were assessed at eight, 16, 24, and 48 hours. Prior to leakage of the alkali from the battery cell there was a reduction in battery voltage, a rise in mucosal pH, and often ulceration or perforation in the digestive tract due to discharge (electrolytic reaction) from the battery. The extent of mucosal injury varied with battery type. Perforation and death were seen in some animals. The extent of mucosal injury was similar in fasted and nonfasted animals. Electrolytic reactions and mucosal injury occurred in both acidic and nonacidic gastrointestinal sites.

Alkalies↗
PubMed1986

Preparation and some properties of carp heavy meromyosin.

Trypsin fragments carp myosin heavy chain into components of lower molecular weight. These changes are concomitant with the loss of Ca2+-ATPase and a weakening in actin-myosin interaction. As heavy meromyosin (HMM) prepared from myofibrils is more homogeneous, the above changes are due to overfragmentation of heavy chain mass. Amino-acid composition of carp and rabbit HMM's are similar, but differences exist in response to DTNB and incorporation.

Actins↗
PubMed1986

Urea tolerance of myofibrillar proteins of two elasmobranchs: Squalus acanthias and Raja tengu.

Some biochemical properties of actomyosin and myosin from elasmobranchs, Squalus acanthias and Raja tengu are compared with those of a freshwater (Cyprinus carpio) and a marine teleost (Seriola quinquiradiata). Whereas Ca2+-ATPase of teleost actomyosins are more stable in the absence of urea, the reverse is true for elasmobranchs up to 1.0 M urea. In contrast to that of teleosts, the Mg2+-ATPase of S. acanthias actomyosin shows an activation in the presence of urea, where as that of R. tengu persists. Below 1.0 M urea, there is low incorporation of DTNB into thiols of elasmobranch myosins, and losses in alpha-helicity are reversible up to 5.0 M urea. The results, thus, demonstrate that for a certain concentration of urea, elasmobranch myofibrillar proteins may exhibit a group specific tolerance to urea.

Actomyosin↗
PubMed1986

[von Recklinghausen's disease associated with pheochromocytoma--an autopsy case report and review of 24 cases in the Japanese literature].

A 56-year-old woman was admitted because of vomiting and right hypochondralgia. Since she was 25 years old, she had been sick with neurofibromatosis. Systemic neurofibromatosis with café-au-lait spots, blood hypertension and tenderness on the right hypochondrium were found. Ultrasonic examination revealed a right adrenal mass. Levels of serum catecholamines were elevated. She developed ileus and died of shock from the release of adrenal catecholamines. Postmortem examination showed right adrenal pheochromocytoma. The tumor measured 11.5 X 8 cm and weighed 25 gm. Von Recklinghausen's disease associated with pheochromocytoma is very rare, and only 24 cases have been reported in Japan. We present our case here with a review of the literature.

Adrenal Gland Neoplasms↗
PubMed1985

Functionality of muscle proteins in gelation mechanisms of structured meat products.

Recent advances in muscle biology concerning the discoveries of a large variety of proteins have been described in this review. The existence of polymorphism in several muscle proteins is now well established. Various isoforms of myosin not only account for the difference in physiological functions and biochemical activity of different fiber types or muscles, but also seem to differ in functional properties in food systems. The functionality of various muscle proteins, especially myosin and actin in the gelation process in modal systems which simulate structured meat products, is discussed at length. Besides, the role of different subunits and subfragments of myosin molecule in the gelation mechanism, and the various factors affecting heat-induced gelation of actomyosin in modal systems are also highlighted. Finally, the areas which need further investigation in this discipline have been suggested.

Actinin↗