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Biomedical subjects

H Hotta

Publications and source records attributed to H Hotta.

160 records · Page 9Linked to original sources
PubMed1971

Serological typing of 31 achromogenic and 40 melanogenic Pseudomonas aeruginosa strains.

Thirty-one achromogenic and 40 melanogenic Pseudomonas aeruginosa strains were studied with 10 monovalent typing sera (3). Twenty-one of the achromogenic (67.7%) and seven of the melanogenic (17.5%) strains were agglutinated by one of the 10 typing sera. Ten achromogenic and 33 melanogenic strains were not agglutinated by any of the 10 typing sera. As far as this set of antisera is concerned, the typability of achromogenic and melanogenic P. aeruginosa strains appears to be much lower than that of the chromogenic, nonmelanogenic strains of the species reported previously.

Agar↗
PubMedDate not supplied

Regulation of Schwann cell nerve growth factor receptor by cyclic adenosine 3',5'-monophosphate.

Previous studies indicated that Schwann cells in immature nerves express nerve growth factor (NGF) receptors, and that this expression is down regulated during development but re-induced by Wallerian degeneration. It was also shown that immature Schwann cells are induced to express galactocerebroside and other molecules characteristic of mature Schwann cells by either contact with an axon or treatment with the cyclic adenosine 3',5'-monophosphate (cAMP) analogues dibutyryl cAMP (dbcAMP) and 8-bromo cAMP or the adenylate cyclase activator forskolin. In the present study, NGF receptors on the surface of cultured Schwann cells were demonstrated by binding of an anti-rat NGF receptor monoclonal antibody or of radioiodinated NGF. Treatment of cultured Schwann cells with cAMP analogues or forskolin resulted in a progressive decrease in both immunoreactive NGF receptors and radioiodinated NGF binding. The cultured Schwann cells contained a polyadenylated RNA species homologous with human melanoma NGF receptor mRNA in sequence and size. The amount of this NGF mRNA was lower in cAMP analogue-treated than in untreated Schwann cells.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMedDate not supplied

Overexpression of the human melanoma-associated antigen ME491 partially suppresses in vivo malignant phenotypes of H-ras-transformed NIH3T3 cells in athymic nude mice.

H-ras-transformed NIH3T3 cells that overexpressed a human melanoma-associated antigen ME491 (44-3H) were generated by transfection with the cloned ME491 antigen gene followed by a 'panning' selection, and effects of the antigen overexpression on H-ras-mediated malignant phenotypes were studied. Although in vitro growth properties of the 44-3H overexpresser cells, both anchorage-dependent and -independent, were practically the same as those of the 44-1C control cells, 44-3H cells exhibited less malignant phenotypes in athymic nude mice (in vivo), i.e. decreased tumourigenicity after subcutaneous inoculation and prolonged survival time after intraperitoneal inoculation, compared with 44-1C cells. These results suggested that overexpression of ME491 antigen partially suppressed malignant phenotypes of H-ras-transformed NIH3T3 cells in athymic nude mice through co-operating with a factor(s) or mechanism(s) that exist in vivo but not in vitro. Thus, ME491 antigen might act as a tumour suppressor under some circumstances.

3T3 Cells↗
PubMedDate not supplied

DNA synthesis inhibition and transmembrane permeation into tumor cells by various dialkyl phthalates upon hyperthermia.

Diisobutyl-, dibutyl-, and dioctyl phthalates, at a concentration of 50 microM, markedly inhibited the incorporation of [3H]thymidine into DNA in tumor cells and also cell proliferation. The inhibitions were synergistically enhanced by hyperthermia at 42 degrees C for 1 h. In contrast, dimethyl-, and diethyl phthalates induced almost no inhibition. The effective phthalates were detected in the cells by gas-liquid chromatography, whereas the non-effective drugs were not or were little detected, suggesting involvement of permeability through cell membrane in cytotoxic effects. Combination of the cytotoxic phthalic acid esters and hyperthermia is suggested to be an advantageous treatment for cancer.

Animals↗
PubMedDate not supplied

Reflex responses of bladder motility after stimulation of interspinous tissues in the anesthetized rat.

OBJECTIVES: To determine the effects of somatic stimulation, including noxious chemical stimulation of interspinous tissues, on bladder motility in the anesthetized rat. METHODS: Changes in pressure in the previously quiescent bladder were measured in anesthetized adult female Wistar rats after various forms of noxious and innocuous somatic stimulation, including injection of the thoracic and lumbar interspinous tissues with capsaicin. Measurements were taken in both central nervous system-intact and spinalized animals, as well as in animals in whom the pelvic nerves had been transected bilaterally. Changes in bladder pressure were also measured in response to electrical stimulation of the primary dorsal ramus of lumbar spinal nerves. RESULTS: Noxious and innocuous stimulation of the fore- and hindpaws and the skin overlying the sacrum generally failed to elicit discernible changes in bladder pressure. However, capsaicin injection of thoracic and lumbar interspinous tissues produced profound and long-lasting increases in bladder pressure. There were no significant differences in the responses to thoracic, as opposed to lumbar, stimulation. Spinalization above the level of stimulation abolished the response to capsaicin injection, as did bilateral transection of the pelvic nerves. CONCLUSION: In general, pressure in the quiescent bladder was relatively insensitive to somatic stimulation. However, noxious chemical stimulation of the interspinous tissues produced a nonsegmentally organized, supraspinal, parasympathetically mediated reflex increase in bladder tone.

Anesthesia↗