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Biomedical subjects

H Kurihara

Publications and source records attributed to H Kurihara.

At least 343 records · Page 19Linked to original sources
PubMed1987

Distribution of microtubules and microfilaments in exocrine (ventral prostatic epithelial cells and pancreatic exocrine cells) and endocrine cells (cells of the adenohypophysis and islets of Langerhans). The relationship between cytoskeletons and epithelial-cell polarity.

We investigated the distribution of microtubules and microfilaments in some exocrine and endocrine cells in rats. Microtubules were stained by applying an immunofluorescent technique using antibodies against beta-tubulin, while microfilaments were stained with rhodamine-phalloidin, which binds selectively to polymerized actin filaments. In the cytoplasm of some exocrine cells (pancreatic acinar cells and ventral prostatic epithelial cells), the microtubules were distributed longitudinally from the apical region to the basal region, but no microtubules were found in the nuclear region. In exocrine cells, most of the microfilaments were localized beneath the apical plasma membrane. In some endocrine cells (those of the adenohypophysis and the islets of Langerhans), the microtubules exhibited a radial or reticular distribution in the cytoplasm, and intense fluorescence was observed in the perinuclear region. The immunofluorescence produced by the antibodies against beta-tubulin was more intense in endocrine cells than in exocrine cells. The microfilaments observed in the endocrine cells studied were homogenously distributed beneath the plasma membrane. Dot-like rhodamine-phalloidin staining was often observed in the cytoplasm of both the exocrine and endocrine cells. The present study clearly demonstrated marked differences in the distribution of cytoskeletal elements in exocrine and endocrine cells, and these may reflect differences in the secretory direction of such cells as well as in epithelial-cell polarity.

Actin Cytoskeleton↗
PubMed1987

Trends in death and consultation rates of ischemic heart disease in Japan and the risk factors in a rural community.

In Japan, the age-adjusted death rate from ischemic heart disease has decreased for both male and female since 1970, although the rate appears to be slightly affected by mortality from senility without mention of psychosis, "cardiac insufficiency", and sudden death in elderly persons. On the other hand, consultation rate has shown an increase, suggesting an increase in the number of recovered patients and a lengthening in the duration of ischemic heart disease from onset to termination by CCU treatment. A 7.5-year prospective study of ischemic heart disease (myocardial infarction + angina pectoris on effort + sudden death) among residents 40 years and older was conducted at a rural community, Akadani-Ijimino district in Niigata Prefecture. Statistically significant risk factors appeared to be age, hypertension, ECG abnormalities and fuduscopic changes. Even in 1977-1984 when Japanese dietary habits were westernized, neither hyperlipidemia nor obesity was related to the development of ischemic heart disease in this agricultural district. Statistically significant risk ratios were not observed for any nutrient or food, although the ratio for animal fat, calcium, salted vegetables and caloric percent of animal protein was more than one respectively.

Adult↗
PubMed1987

Pharmacodynamic aspects of in vitro and in vivo chemosensitivity tests.

To determine the optimal conditions for clonogenic assay, the antitumor activities of 5-fluorouracil (5-FU) in vitro and in vivo were compared from a pharmacodynamic viewpoint in a human carcinoma xenograft-nude mouse system. In the clonogenic assay, tumor cells were exposed to 5-FU continuously for 2 weeks, and the results of the assay were evaluated in terms of colony survival rates (T/C). Tumor-bearing BALB/c male nude mice were treated with 5-FU, and the results were evaluated in terms of the lowest values of relative mean tumor weights (T/C). To compute the area under the curve (AUC) after administration of 5-FU in vitro and in vivo, agar and serum levels of 5-FU were measured by bioassay. Antitumor activities in terms of T/Cs against a gastric carcinoma strain (H-111) depended highly on the AUCs in vitro and in vivo. The T/C in vitro (z) was correlated with the AUC in vitro (w), z = 58.4 x 0.99331w, and the T/C in vivo (y) was also correlated with the AUC in vivo (x), y = 52.1 x 0.88552x. On the assumption that the T/Cs of these two regression equations were equivalent (y = z), a correlation between w and x was derived. To predict the T/C at the maximum tolerated dose of 5-FU in mice, the optimal drug concentration in vitro was calculated to be 2.7 micrograms/ml, which also proved to be suitable for seven other carcinoma strains. Our experimental system was thought to be adequate for selecting the optimal drug concentration in the clonogenic assay.

Animals↗
PubMed1987

[Hormone therapy as postoperative care in patients with differentiated thyroid cancer].

TSH suppression therapy has been performed for 150 patients as postoperative care for differentiated thyroid cancer. L-thyroxine (LT4) was given in a dose of 2.1-4.8 micrograms/kg/day, per os. Serum thyroid hormone determinations were done after confirming that the drug had continually been taken for more than three months. Serum free T4 (FT4) values were elevated higher than the upper normal limits (1.9 ng/dl) in 127 of 150 cases (84.7%). In 100 cases of these, serum free T3 (FT3), reverse T3 (rT3) and TSH were estimated. In 98 cases (98%), serum FT3 was within the normal limits (3-6 pg/ml) and no correlation was found between values of FT4 and FT3. These serum rT3 values, however, were elevated higher than the normal range (13-43 ng/dl) in 41 cases (41%) correlating with FT4 values. Serum TSH, FT4 and FT3 showed no correlation with given LT4 doses. There was no correlation between the serum TSH and FT3. However, some correlation (r = -0.4046) was found between serum TSH and rT3 values. From these results the following conclusions were obtained: i) There must be some auto-regulating mechanisms to keep the serum FT3 values at the normal level by promoting a de-iodinating process from T4 to rT3 when serum T4 level increased, since rT3 has no hormone activity. ii) Administration of synthesized LT4 is safer and more adequately usable than synthesized L-triiodothyronine or desiccated thyroid, as the TSH suppression therapy, because the above mentioned autoregulating mechanism would take place.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined Modality Therapy↗
PubMed1986

Multigranular exocytosis induced by phospholipase A2-activators, melittin and mastoparan, in rat anterior pituitary cells.

Effects of phospholipase A2-activators, melittin and mastoparan, on rat anterior pituitary cells were studied by use of the electron microscope. Rat anterior pituitaries were incubated in HEPES buffer containing 20 micrograms/ml of melittin or the same dose of mastoparan for 5 min, 10 min and 20 min. Features indicating discharge of granule contents by exocytosis were increased with time, and the simultaneous extrusion of a number of secretory granules, named "multigranular exocytosis", was often recognized in addition to single-granule exocytosis at 10 min and 20 min. Most membrane pits, where the multigranular exocytosis as well as the single-granule exocytosis occurred, were coated. Moreover, a large number of vesicles coated or non-coated were distributed near the trans side of the Golgi apparatus of melittin-treated or mastoparan-treated cells after 20 min. These vesicles might be related to membrane internalized from the excess surface membrane derived from the limiting membrane of exocytosed granules. These observations indicate that phospholipase A2-activators induce hormone release involving membrane fusion between limiting membranes of secretory granules, and between granule-limiting membrane and plasma membrane in rat anterior pituitary cells.

Animals↗
PubMed1986

A case of Takayasu's disease with ruptured carotid aneurysm.

Recently, a number of cases of Takayasu's disease having dilatative or aneurysmal lesions have been reported. Such lesions have come to be considered important manifestations of Takayasu's disease. A case, whose right common carotid artery perforated spontaneously and became a pseudoaneurysm, without any other stenotic lesion is presented with a review of the literature. Surgical treatment was performed successfully.

Adult↗
PubMed1986

[Clinical study of clonogenic assays--with reference to adjuvant cancer chemotherapy after operation].

One hundred surgical specimens were used for the clonogenic assay to determine the chemosensitivity in vitro and the results were compared with the antitumor effect of the adjuvant cancer chemotherapy after operation. The clonogenic assay was performed according to the method of Salmon et al. The dissociated tumor cells were contacted with drugs in a concentration of 1 microgram/ml for 1 hr. (mitomycin C; MMC) or 2-3 wks. (5-fluorouracil; 5-FU). Fifty percent or more inhibitory rate of the colonies were evaluated as positive. The clinical antitumor effects were assessed by the tumor reduction in non-curatively operated cases and by the survival period after the operation in curatively operated cases. Overall evaluable cases were 52 of 100 cases with a median cloning efficiency rate of 0.1%. The efficacy rates of the drugs in vitro were found to be 21.3% for MMC and 31.8% for 5-FU. The histological differentiations, Stages, pretreatments and cloning efficiency rates were observed to have few influence on the chemosensitivity. Nineteen non-curatively operated cases were eligible for the comparison between in vitro and in vivo, showing 40% true positive, 100% true negative and 84.2% predictable rates. In curatively operated cases, whereas 2 of 14 cases have died of cancer in not adapted adjuvant cancer chemotherapy group, no cancer deaths were encountered in 7 cases whose adjuvant cancer chemotherapy was evaluated as effective in the clonogenic assay. From these findings, it was concluded that in vitro clonogenic assay might be useful to select a suitable adjuvant cancer chemotherapy in curatively operated cases as well as cases with advanced carcinomas.

Antineoplastic Agents↗
PubMed1984

Cancer in collagen disease. A statistical analysis by reviewing the Annual of Pathological Autopsy Cases (Nippon Boken Shuho) in Japan.

Cases of systemic lupus erythematosus, systemic sclerosis, periarteritis nodosa, and dermato- and polymyositis autopsied in Japan during a recent, 7-year period (1972-1978) were studied to assess the incidence of cancer as a complication. In comparison with the other three groups, cases of dermato- and polymyositis (DP) showed quite a high incidence of malignancy: 53 of 99 for males (53.5%) and 36 of 139 for females (25.9%). In patients older than 50 years of age cancer was recognized in the autopsies of 65.7% of males and 38.2% of females with DP. The stomach was both the primary site and had the highest incidence of cancers in DP (62.3% males, 27.8% females). It was concluded that DP has a strong association with the development of cancer, particularly gastric carcinoma, in Japan.

Adolescent↗