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Biomedical subjects

K Hidaka

Publications and source records attributed to K Hidaka.

At least 127 records · Page 7Linked to original sources
PubMed1987

Altered interaction between Sendai virus and a Chinese hamster cell mutant with defective cholesterol synthesis.

An amphotericin B-resistant mutant (AMBr-1) isolated from the Chinese hamster V79 cell line is defective in a pathway for sterol synthesis and contains a much reduced free cholesterol level as compared with the parental V79. The character of the plasma membrane of AMBr-1 was compared with that of V79 by measuring the fusion with the envelope of the Sendai virus and also by measuring membrane fluidity: AMBr-1 was found to be more sensitive to Sendai virus-induced cytolysis than V79. Both assays for membrane-permeability change and electron spin resonance (ESR) study showed an enhanced response to the fusion between viral envelope and plasma membrane in AMBr-1 cells. Measurement of the fluorescence polarization for 1,6-diphenyl-1,3,5-hexatriene suggested that the membrane of AMBr-1 was more fluid than that of V79. This aberrant nature of the cell membrane of AMBr-1 might be caused by the altered membranous sterol content.

Animals↗
PubMed1987

Isolated tissue and binding studies of YM-17690, a novel and non-analogous leukotriene agonist.

YM-17690, 3-[4-carboxymethoxy-3-[p-(4-phenylbutoxy) benzamido]phenyl]propionic acid, produced a dose-dependent contraction of guinea-pig ileum and its EC50 value was 1.6 X 10(-8) M. The response was not affected by pretreatment with atropine, mepyramine, indomethacin, dazoxiben and AA-861 (a 5-lipoxygenase inhibitor), but was inhibited by FPL-55712 (an LTD4 and LTE4 antagonist). YM-17690 induced dose-dependent contractions of guinea-pig lung parenchyma and trachea with EC50 values of 3.9 X 10(-9) and 2.2 X 10(-8) M, respectively. Pretreatment of these tissues with FPL-55712 resulted in a parallel shift of the YM-17690 dose-response curves to the right. The pA2 values for FPL-55712 in lung parenchyma and trachea were 7.41 and 8.21, respectively, and the slopes of the regression lines of Schild plots were 1.00 and 1.02, respectively. YM-17690 produced a dose-dependent inhibition of [3H]LTD4 binding to guinea-pig lung membranes and its pKi value was 9.28. However, the compound showed only 25% inhibition of [3H]TLC4 binding to guinea-pig hippocampus membranes, even at 10(-5) M. These results suggest that YM-17690 is a selective leukotriene (LTD4 and LTE4) agonist and that it will therefore be a valuable tool in the study of actions of leukotrienes and for the characterization of their receptors.

Animals↗
PubMed1987

[The management of malignant ascites with a streptococcal preparation, OK-432: relation between the clinical effect and auto-tumor cell killing activity by OK-432-induced ascites-derived lymphocytes].

Twelve patients with malignant ascites caused by gastro-intestinal cancer were treated by intraperitoneal administration of OK-432. Tumor cells from these patients were separated from ascitic fluid and cultured in vitro before OK-432 therapy. OK-432 was given intraperitoneally one to two times a week at doses ranging from 5 to 20 KE suspended in saline. Mononuclear lymphocytes were collected from the fluid at various intervals throughout the therapy. The effect of ascites-derived lymphocytes on ascites-derived autologous tumor cell growth was studied in vitro using microplate assay. Nine (responders) of 12 patients showed complete disappearance or significant reduction of ascitic fluid. Ascites-derived lymphocytes slightly inhibited autologous tumor cell growth only in one case before OK-432 therapy. Lymphocytes collected from ascites after OK-432 injection significantly inhibited auto-tumor cell growth in all of 9 responders. In 3 non-responders, however, auto-tumor cell growth inhibition was found only in one case. Interestingly, lymphocytes from non-responders significantly inhibited the growth of tumor cells taken from responders. Conversely, lymphocytes from responders did not inhibit non-responder-derived tumor cell growth. These findings imply that auto-tumor killing by OK-432-induced lymphocytes may depend more on the condition of the tumor cells than on the condition of the lymphocytes, and that the measurement of auto-tumor killing activity by ascites-derived lymphocytes may be useful as an indicator in OK-432 therapy.

Abdominal Neoplasms↗
PubMed1985

Amphotericin B enhances efficiency of DNA-mediated gene transfer in mammalian cells.

Using plasmids containing the genes for thymidine kinase (tk) and neomycin resistance (neo), we have shown that DNA-mediated genotypic transformation of L and Chinese hamster ovary (CHO) cells is increased several-fold by the presence of the sterol-binding polyene antibiotic, amphotericin. Transformation into the same host cells, using genomic DNA, was also enhanced by amphotericin. Phenotypic expression of beta-galactosidase activity of a plasmid containing the gene for the enzyme was also markedly elevated when the antibiotic was added at transfection. Other sterol-binding polyene antibiotics also showed activity in these DNA-mediated gene transfer assays.

Amphotericin B↗
PubMed1985

Potentiation by squalene of antitumor effect of 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-nitros ourea in a murine tumor system.

The effect of squalene (SQ) on the antitumor activity of 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitros our ea (ACNU) was studied in a murine tumor system. SQ at 4.2 g/kg exhibited a significant potentiating effect on the activity of 10 mg/kg of ACNU against lymphocytic leukemia P388 and resulted in some long-term survivors without toxicity to the host. Simultaneous administration of SQ and ACNU was most effective.

Animals↗
PubMed1984

[Bronchial asthma due to inhaled chloroplatinate].

Platinum and its compounds have characteristics that make them excellent oxygen sensors, and in recent years they have come to be used in large amounts in the manufacture of internal combustion engines. Recently, there have been detected among workers engaged in making platinum oxygen sensors, dermatitis and bronchial asthma which appear to be ascribable to exposure to chloroplatinate. This is a study of their etiology from the viewpoint of industrial hygiene and clinical medicine. The results obtained are as follows: Platinum-induced allergic disorders developed in a worker who applies about 50% chloroplatinate to zirconia porcelain. Although the concentration of platinum in the air was 2 microgram/m3 or less as determined by ACGIH, the worker was directly exposed to the dried powder of ammonium chloroplatinate with relatively high concentration; while the exposure was intermittent and topical, it resulted in aspiration of the powder. Bronchial asthma observed in 2 of 16 workers (12.5%) was reactive in a skin drop test with 1% chloroplatinate, and typical bronchial asthma was induced in an environmental provocation test carried out in a room where platinum sensors are made. Parameters obtained from periphero-hematological and immuno-serological tests were within the normal range. The main symptoms revealed by physical examination of workers exposed to chloroplatinate contact dermatitis in 11 (78.6%), pharyngeal irritation in 6 (42.9%), nasal obstruction in 2 (14.3%), frequent sneezing, coughing, and sputum in one each.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Hb Albany-Suma (alpha 11 [A9] Lys----Asn), a hemoglobin variant with slightly elevated oxygen affinity in Japan.

A fast-moving abnormal hemoglobin was detected in a heterozygous condition from a patient with benign goiter. The hemoglobin has a slight but significant high oxygen affinity. The patient does not show any hematologic abnormality. Structural analysis indicated that a lysine residue normally present at alpha 11 was substituted by an asparagine residue. This substitution which has not been described previously was discovered coincidentally by another laboratory (1). The new variant has been named Hb Albany-Suma to denote the origin of the variant in both the United States and Japan.

Aged↗