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Biomedical subjects

C Tomioka

Publications and source records attributed to C Tomioka.

8 recordsLinked to original sources
PubMed1993

A comparison of induced heat-shock protein in neurons destined to survive and those destined to die after transient ischemia in rats.

We examined the induction of heat-shock protein (HSP) in CA-1 pyramidal neurons compared with that in CA-3 pyramidal neurons, in rat brain following 20 min of ischemia. The time course of the changes of localization of HSP was investigated using immunohistochemical and Western blot analyses. The induction of HSP in the CA-1 subfield was the same as that in the surviving hippocampal CA-3 subfield.

Animals↗
PubMed1992

Absence of early destructive changes of cytoskeletal proteins after transient ischemia in the rat.

We examined the changes in immunoreactivity of microtubuli-associated protein (MAP) 2 in dendrites by immunohistochemical analysis following 20 min of cerebral ischemia in the rat. A decrease of immunoreactivity of MAP 2 in dendrites in the CA1 subfield of the hippocampus was observed on days 3 and 7 but not on day 1 after ischemia. Early destructive changes of this protein were not observed, a finding which was confirmed by polyacrylamide gel electrophoresis analysis. We elucidated one factor which indicated that destruction of the dendrites of CA1 pyramidal neurons would not take place any earlier than the destruction of the neurons themselves after ischemia in rats.

Animals↗
PubMed1992

Resistance of hippocampal CA-1 noradrenergic fibers to five minutes of transient cerebral ischemia in the gerbil.

We examined changes in the tyrosine hydroxylase (TH)-immunoreactive fibers following 5 min of cerebral ischemia in gerbils using an immunohistochemical method 1, 3 and 30 days after ischemia. Almost all CA-1 pyramidal neurons were lost 3 days after ischemia, whereas noradrenergic fibers were maintained 30 days after ischemia. The present study demonstrated that TH-immunoreactive fibers and cells were resistant to transient ischemia, and that there was no sprouting or hyperactivity in noradrenergic systems after ischemia.

Adrenergic Fibers↗
PubMed1991

Decrease of pre-synaptic noradrenergic fiber density in rat hippocampus after transient ischemia.

The selective loss of hippocampal CA-1 pyramidal neurons has been reported not to be accompanied by damage to presynaptic terminals in the stratum radiatum as shown by electron microscopic observations. However, we examined changes in the tyrosine hydroxylase (TH) immunoreactive fibers following transient ischemia in rats using an immunohistochemical method 1, 3, 7 and 30 days after ischemia. The present study indicates that ischemic neuronal injury spreads to pre-synaptic fibers after the disappearance of the post-synaptic CA-1 pyramidal neurons.

Adrenergic Fibers↗
PubMed1983

A possible role of protein kinase C in signal-induced lysosomal enzyme release.

In platelets, activation of protein kinase C and mobilization of Ca2+ were selectively induced by the addition of 1-oleoyl-2-acetyl-glycerol and a low concentration of A23187, respectively (Kaibuchi, K., Takai, Y., Sawamura, M., Hoshijima, M., Fujikura, T. and Nishizuka, Y. (1983) J. Biol. Chem. 258, 6701-6704). Using this procedure evidence was obtained suggesting that the protein phosphorylation and Ca2+ mobilization were both essential and synergistically effective to cause release of lysosomal acid hydrolases such as N-acetylglucosaminidase. A similar observation was made for the lysosomal enzyme release from rat neutrophils.

Animals↗
PubMedDate not supplied

[Therapeutic colonoscopy in patients with colonic and rectal polyps].

598 colorectal polyps were removed by therapeutic colonoscopy from 377 patients, of both sexes, between 1 and 88 years old, most of them with lower digestive symptoms. The polyps were unique in 67.37% and multiple in 32.63% of patients, and mostly located in rectum and sigmoid colon; 42.14% were pedunculated, 33.95% sessile++/sub-pedunculated, and 23.91% sessile in shape. In 51% the size was over 10 mm in diameter. Histologically, 68.68% were of epithelial neoplastic type: 60.91% adenoma; 6.42% adenoma with adenocarcinoma, and 1.35% polypoid carcinoma. 30.64 were epithelial non-neoplastic type: 20.32% hyperplastic polyp, and 0.51% hyperplastic polyp with tubular adenoma. Two patients (0.53%) had lower digestive hemorrhage immediately after the polypectomy. The complications were controlled with conservative measures without blood transfusion.

Adolescent↗
PubMedDate not supplied

[Adenoma of the colon and rectum].

318 adenomatous polyps were removed by colonoscopic polypectomy, from two hundred patients, between 25 to 88 years old; 60.50% men, and 39.50% women. 86.50% of patients were older than 50 years old. In 64.50% of patients the adenomatous polyp was single, and 35.50% had "multiple adenoma"; the lesions distribution was 72.64% in the rectum-sigmoid colon. The grade of dysplasia was severe in adenomas over 20mm, and in those of villous type. The malignant percentage was: 1.61% in the adenomatous polyp under 10mm in diameter, 8.49% in those of 10mm to 19mm, and 30.68% in the adenomas of 20mm or more. The adenocarcinomatous focus increased from 1.69% in the adenomas under 10mm to 58.33% in those of 40mm or more in diameter. The relationship between type of adenomatous polyp and his adenocarcinoma incidence was 7.66% in tubular type, 22.22% in tubular-villous, and 26.32% in villous type. The carcinoma incidence in all of the adenomas of this series was 11.95%.

Adenoma↗