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Biomedical subjects

H Asai

Publications and source records attributed to H Asai.

At least 127 records · Page 7Linked to original sources
PubMed1985

[Combination chemotherapy with peplomycin, cis-platinum and mitomycin C in gynecologic cancer].

Eight patients with gynecologic cancer (cervix: 6, corpus: 1 and vulva: 1) were treated with combination chemotherapy, PPM therapy consisting of continuously infused PEP 4mg/m2 days 1-5, CDDP 13 mg/m2 days 1-5, and MMC 3mg/m2 day 1. This was repeated every three to five weeks. Six of the eight patients were evaluable, two had a complete response and one had a partial response, for an overall response rate of 50%. Because of hematological toxicity, blood transfusion was carried out in four patients. Nephrotoxicity and pulmonary toxicity were slight. Nausea and vomiting were controlled with dexamethasone and domperidone. PPM therapy is considered to be an effective and useful combination chemotherapy for patients with gynecologic cancer.

Adenocarcinoma↗
PubMed1985

Fatal antral ulcer in conventionally fed W/Wv mutant mice given indomethacin by injection.

Antral ulcers develop spontaneously in (WB X C57BL/6)F1-W/Wv mice. Most W/Wv mice with severe ulcers die within 3 months after birth. When healthy-looking W/Wv mice were selected at 4 months of age, 80-90% of them were free from the ulcer. Even if the ulcer was present, it was small. The authors compared the susceptibility of such healthy-looking W/Wv mice to ulcerogenic treatments with that of the congenic +/+ mice. Stress caused development of fundic erosions in both W/Wv and +/+ mice. The susceptibility of the W/Wv mice to either cold or water-immersed stress was not higher than that of the +/+ mice. Topical administration of aspirin produced erosions in both fundus and antrum. The susceptibility of W/Wv mice to aspirin was comparable to that of the +/+ mice in either the starved or the fed condition. Subcutaneous injection of indomethacin produced both fundic erosions and antral ulcers in the starved condition, but it produced only antral ulcers in the conventionally fed condition. The susceptibility of the starved W/Wv mice to indomethacin was not higher than that of the starved +/+ mice. In contrast, the fed W/Wv mice were significantly more susceptible to indomethacin than the fed +/+ mice. A considerable proportion of the fed W/Wv mice died of blood loss from the ulcer within 24 hours. The size of the ulcer of the W/Wv mice was significantly larger than that of the +/+ mice. Both genetic and feeding conditions seem to determine the susceptibility to indomethacin.

Animals↗
PubMed1985

[The clinical significance of CA125 in patients with gynecological tumors--a comparative study on CA125 and other tumor markers].

Serum CA125 levels were measured by radioimmunoassay patients with various gynecological tumors. Elevated levels of CA125 were detected in the serum of patients with malignant ovarian tumors. Among patients with uterine tumors, CA125 levels were elevated in those with malignant uterine tumors, but not with uterine myomas. The correlations between tumor markers (CA125, IAP, ferritin, PTA) and malignant ovarian tumors were measured, and only CA125 levels were found to correlate with progression or regression of the disease in patients with malignant ovarian tumors. These results suggest that CA125 may be a useful marker for monitoring the response to treatment in patients with malignant ovarian tumors.

Adenocarcinoma↗
PubMed1984

Structural difference between two ATP-binding sites of heavy meromyosin revealed by the dynamic fluorescence quenching technique.

Acrylamide fluorescence quenching of 1,N6- ethenoadenylyl imidodiphosphate (e-AMPPNP) bound reversibly to the ATP binding sites of heavy meromyosin was investigated. In the presence of a 6-fold excess of heavy meromyosin over e-AMPPNP, a modified Stern-Volmer plot was not a linear function of the inverse of the concentration of acrylamide used as a quencher. By analyzing the plot, two Stern-Volmer constants (0.89 M-1 and 13 M-1) were obtained for bound e-AMPPNP. About 94% of bound e-AMPPNP had the Stern-Volmer constant of 0.89 M-1 and 6% of bound e-AMPPNP had the Stern-Volmer constant of 13 M-1. Moreover, in the presence of a 10-fold excess of e-AMPPNP over heavy meromyosin, a curved Stern-Volmer plot was obtained. It was found from this plot that 50% of bound e-AMPPNP had the Stern-Volmer constant of 13 M-1 and the remainder had the Stern-Volmer constant of 0.89 M-1. From these and the above data, it was concluded that one of the two ATP-binding sites of heavy meromyosin binds e-AMPPNP much more tightly than the other site does, and that the fluorescent group of e-AMPPNP bound to the former site is strongly isolated from the solvent as compared with that of e-AMPPNP bound to the latter site.

Adenosine Triphosphate↗
PubMed1984

Polydispersity effects on head-to-tail polymerization of F-actin. A theoretical treatment.

A theoretical description of the release of labeled subunits of F-actin that undergoes head-to-tail polymerization utilizing random-walk theory is extended to the case of a finite-length polymer. An exact expression is given for the number of released subunits in a suitable form for numerical calculation. By comparing the results for a finite-length polymer with that for an infinite-length case, the limitation of the infinite-length approximation is readily known. The results for finite-length polymers are applied to systems with polydispersity. It is shown that the number of labeled subunits released from F-actin depends strongly on the distribution functions of the polymer lengths and the values of the transition probabilities of the random walkers.

Actins↗
PubMed1984

On the rotational brownian motion of a bacterial idle motor. I. Theory of time-dependent fluorescence depolarization.

A rotational diffusion equation and its Green's function for a spheroidal particle such as a bacterial body, to which an actively driving but idle motor is attached, are presented. As an application of the theory, general expressions for the time-dependent fluorescence depolarization caused by such a particle have been obtained. Measurement of such depolarizalion should provide a useful tool for determination of the rate of revolution of the rotating motor attached to cell bodies such as bacteria under various solution conditions, if a fluorescent (or phosphorescent) label is attached to the motor shaft.

Journal Article↗
PubMed1983

Binding of beta-naphthyl triphosphate to human adult hemoglobin accompanying deoxygenation. Investigated by simultaneous measurements of fluorescence, absorbance and partial pressure of oxygen.

Binding of a fluorescent allosteric effector, beta-naphthyl triphosphate (beta-NapP3), to human adult hemoglobin (HbA) at various levels of oxygen saturation were investigated by simultaneous measurements of fluorescence, absorbance and oxygen partial pressure. Amounts of beta-NapP3 bound to HbA were easily estimated from the fluorescence intensities of HbA solutions, because it was previously proved that the fluorescence of beta-NapP3 bound to HbA is completely quenched. Exchange reactions of the above fluorescent allosteric effector with 2,3-bisphosphoglycerate (DPG) were also examined at various levels of oxygen saturation. It was found that beta-NapP3 binds to deoxyHbA tetramer in the molar ratio of 2:1, and that one of the two beta-NapP3 competes with DPG. It was also found that beta-NapP3 binds to completely oxygenated HbA tetramer in the molar ratio of 1:1, and that the bound beta-NapP3 was not released by adding DPG. The binding affinity of beta-NapP3 for the noncompetitive site of completely oxygenated HbA, to which DPG does not bind, was smaller than that for the noncompetitive site of deoxyHbA, to which DPG also does not bind. Furthermore, the correlations between oxygen bindings by HbA and the bindings of beta-NapP3 to HbA in the intermediate stages of deoxygenation were investigated. It was revealed that HbA as a tetramer exists in three conformational states rather than simple two states as Monod, Wyman, and Changeux had proposed.

Binding Sites↗
PubMed1982

A reaction cell with short optical path and oxygen electrode compartment for convenient quantitative determination of oxygen binding by hemoglobin.

1. A simple and compact apparatus, with which the oxygen equilibrium of hemoglobin can be determined easily, was constructed and its performance was examined. 2. The oxygen partial pressure and the degree of oxygen saturation in a hemoglobin solution were determined by combined used of a Clark oxygen electrode and a spectrophotometer. 3. This apparatus can be used in a usual 1 cm square cell holder of a commercial spectrophotometer without any modifications, and has the advantage that the light path length of the optical cell is variable and can be shortened to about 2 mm.

Adult↗
PubMed1982

Extraction and some properties of the proteins, Spastin B, from the spasmoneme of Carchesium polypinum.

Proteins of the contractile spasmoneme from Carchesium polypinum were extracted in 2% SDS, 30% acetic acid, or 8 M urea. The proteins extracted in SDS had a wide molecular weight distribution when examined by SDS-polyacrylamide gel electrophoresis. On the other hand, the proteins extracted in urea and acetic acid had three major peaks with molecular weights of about 16,000, 18,000, and 22,000. Most of these proteins were soluble even in the absence of urea and furthermore were found to be monomeric, since the sedimentation coefficient, s20,w, measured by analytical ultracentrifugation was 2.0S. The electrophoretic mobility of the proteins extracted in urea or in acetic acid was examined on alkaline gels. In the presence of free Ca2+, the mobility was significantly reduced compared with that in the absence of free Ca2+. These Ca-binding proteins were heat-stable and could not interact with troponin I. The implications of these proteins and others in relation to the contractility of the spasmoneme in Carchesium stalk are discussed.

Animals↗