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Biomedical subjects

E Kobayashi

Publications and source records attributed to E Kobayashi.

At least 361 records · Page 20Linked to original sources
PubMed1991

[A case of mediastinal cavernous hemangioma].

A case of mediastinal cavernous hemangioma was reported. An asymptomatic 6-year-old girl was discovered to have a mass in the left anterior superior mediastinum on a routine chest x-ray film. Computed tomograms demonstrated a mediastinal mass with calcification. Under a median sternotomy, a 10 x 9 x 5 cm mass was resected after dissecting the connections to the pericardium. As the mass surrounded the left phrenic nerve, the nerve was resected with the tumor. The histopathology was cavernous hemangioma. The calcification was not found in the vessels as the phleboliths but was showed in the interstitial tissues.

Calcinosis↗
PubMed1991

[The actual situation in surgical management of occlusive cerebrovascular disease].

We studied 828 cases with occlusive cerebrovascular disease who were admitted to our hospital over these 5 years in relation to surgical management. Cerebral angiography including digital subtraction angiography was carried out in 770 cases. Surgical management was carried out in 110 cases; 77 cases of carotid endarterectomy (CEA), 18 cases of EC-IC bypass and 15 cases of external decompression. The ratio of surgical management was 13. 3% of all cases admitted. The mortality and the morbidity were 5.4% and 1.8% respectively. The number of EC-IC bypass has decreased gradually after the reports of international cooperative study concerning with EC-IC bypass in 1985. But the number of CEA has increased gradually.

Aged↗
PubMed1990

Restriction fragment length polymorphisms detected in N-ras-related sequences of rats and their linkage analyses.

Novel restriction fragment length polymorphisms (RFLPs) in inbred rats were revealed with the human N-ras gene as probe. Three fragments hybridizing to the probe were detected by Southern blot hybridization under highly stringent conditions, and one of the fragments showed variation in inbred rat strains. Furthermore, on hybridization under low-stringency conditions, an additional fragment hybridizing to the probe was observed, and this fragment also showed interstrain variation. These two variant fragments showed different distributions in 27 inbred rat strains and segregated in backcross progeny as codominant alleles of independent single autosomal loci. Therefore, the loci for these RFLPs were named Nras-1 and Nras-2, respectively. Analyses of linkages between the RFLPs and 11 other loci revealed that the Nras-2 locus was closely linked to the c locus (3.7 +/- 2.6%), which belongs to rat linkage group I.

Animals↗
PubMed1990

Age-related changes in strontium to calcium ratios in rat tissues.

The Sr/Ca ratios in plasma, urine, bone, and soft tissues for various ages after weaning in male and female rats were determined to examine the effects of aging on the discrimination between strontium (Sr) and calcium (Ca) under physiological conditions. Age-related changes in the Sr/Ca ratios were similar in all tissues; the Sr/Ca ratios decreased rapidly until about 25-wk-old and then slowly, from that period on, reaching much lower values than in the diet. When the logarithm of the Sr/Ca ratio in each tissue was plotted against the logarithm of age, a linear relationship was observed with statistically significant (p less than 0.05) regression lines. The higher levels of Sr/Ca ratios in all tissues of the younger rats could be explained by the high efficiency of Sr absorption by the small intestine early in life. Parameters for the equations between age and Sr/Ca ratio differed with tissues, suggesting the existence of specific discrimination mechanisms in each tissue.

Aging↗
PubMed1990

Discriminative uptake of metals by the liver and its relation to induction of metallothionein by cadmium, copper and zinc.

1. Disappearance from plasma and uptake by the liver of cadmium (Cd), copper (Cu) and zinc (Zn) were examined with a view to studying the biological discrimination between essential and non-essential heavy metals. 2. Cd injected intravenously at a single dose of 0.8 mg/kg body wt disappeared from rat plasma rapidly within about 10 min, while Cu and Zn injected at the same dose disappeared slowly in plasma and decreased to the control level after about 3 hr. 3. Uptake of Cd by the liver corresponded well with the rapid disappearance from plasma, while Cu and Zn accumulated slowly in the liver and their concentrations started to increase after their plasma concentrations had decreased. 4. Metallothionein was induced in the liver at a similar time course for the three metals, suggesting the presence of discriminative uptake processes by the liver with similar or the same detoxification mechanisms through induction of metallothionein.

Animals↗
PubMed1990

The kapurimycins, new antitumor antibiotics produced by Streptomyces. Producing organism, fermentation, isolation and biological activities.

As a result of screening for antitumor agents from actinomycetes, the kepurimycins were isolated from Streptomyces sp. DO-115. The antibiotics were produced in a fermentation medium supplemented with high porous polymer resin which adsorbs antibiotics and results in an increase of titer. The active complex was isolated from the polymer resin by a solvent extraction procedure and was separated by column chromatography, into two minor and one major component, named A1, A2 and A3. The kepurimycins were active against bacteria, particularly Gram-positive organisms, and were cytotoxic to HeLa S3 human cerivical cancer cells and T24 human bladder carcinoma cells in vitro. Among the individual components of the kapurimycins, kapurimycin A3 exhibited the strongest antibacterial and cytotoxic activities. It showed a potent antitumor activity against murine leukemia P388 in vivo.

Animals↗
PubMed1990

[A case report of great omental leiomyosarcoma with perforation into the jejunum].

The case is a 56-year-old woman, who came to our hospital for bloody flux as chief complaint. Small intestine radiography examination revealed findings suspected of jejunal leiomyosarcoma, but selective angiography confirmed a tumor deep-infected image with omental artery alone as arteria nutricia, leading to the diagnosis as omental tumor.

Female↗
PubMed1990

Potent selective inhibition of 7-O-methyl UCN-01 against protein kinase C.

UCN-01 is a staurosporine-related compound that was isolated from the culture broth of Streptomyces sp. and shows potent and selective inhibitory activity against protein kinase C. Cellular inhibitory activity of UCN-01 against protein kinase C and cytotoxicity of UCN-01 were compared with those of staurosporine. When the mechanism of inhibitory activity was investigated in vitro, UCN-01 as well as staurosporine inhibited the activity of the catalytic domain of protein kinase C. In spite of direct inhibition against the catalytic domain of protein kinase C, cytotoxicity of UCN-01 was much lower than that of staurosporine. In addition, UCN-01 showed more selective inhibitory activity against protein kinase C than did staurosporine because of the sole structural difference at C-7. Therefore, a series of 7-O-alkyl derivatives of UCN-01 was synthesized and investigated. Interestingly, one of the compounds, the beta-methoxy derivative, showed 3-fold greater potency and 17-fold more selective inhibitory activity against protein kinase C than did UCN-01.

Alkaloids↗
PubMed1989

Hypericin and pseudohypericin specifically inhibit protein kinase C: possible relation to their antiretroviral activity.

Hypericin and pseudohypericin which have been isolated from plants of the Hypericum family are aromatic polycyclic diones. Daniel Meruelo et. al. have reported that hypericin and pseudohypericin showed potent antiretroviral activity including anti-human immunodeficiency virus (1,2). However, the mechanism of these antiretroviral activities has not been clarified. In the course of screening specific inhibitors of protein kinase C we have found that both compounds specifically inhibit protein kinase C with IC50 values 1.7 micrograms/ml and 15 micrograms/ml, respectively, and show antiproliferative activity against mammalian cells. These data suggest that antiretroviral activity of hypericin and pseudohypericin could be attributable to the inhibition of some phosphorylation involved by protein kinase C during viral infection of cells.

Animals↗
PubMed1989

Anesthesia for a patient with recessive dystrophic epidermolysis bullosa.

Two different anesthetic methods were employed for a patient with recessive dystrophic epidermolysis bullosa (R-DEB). One was plexus brachial block in combination with ketamine infusion. The other was general anesthesia with N2O-O2-halothane via a face mask. In the former, no particular problem developed. In the later, however, some blisters were newly formed on the region where the anesthesist's fingers were attached to hold a face mask. Although mask anesthesia was considered to be not always suitable for patients with DEB, we chose it because tracheal intubation may cause more serious damage to the upper airway leading to airway obstruction.

Journal Article↗
PubMed1989

Calphostin C (UCN-1028C), a novel microbial compound, is a highly potent and specific inhibitor of protein kinase C.

Calphostin C (UCN-1028C), a newly isolated compound from Cladosporium cladosporioides, is a potent and specific inhibitor of protein kinase C, because it was 1000 times more inhibitory to protein kinase C (IC50, 0.05 microM) than other protein kinases such as cAMP-dependent protein kinase and tyrosine-specific protein kinase (IC50, greater than 50 microM). Calphostin C did not inhibit calcium activated neutral protease (calpain)-digested protein kinase C, indicating that it interacts with the regulatory domain of protein kinase C. In addition this compound showed inhibitory effects on the binding of [3H]PDBu to protein kinase C. The potent cytotoxic activity and antitumor activity of calphostin C might be due to the inhibition of protein kinase C, and thus it may be potentially useful for the therapeutic application.

Animals↗
PubMed1989

Pulmonary clearance and toxicity of zinc oxide instilled into the rat lung.

Pulmonary toxicity of zinc oxide (ZnO) was evaluated by investigating the metabolic fate and inflammatory potency of ZnO instilled into the rat lung. Groups of three rats received single intratracheal instillations of ZnO suspension at a dose of 100 micrograms Zn/rat in the time-course experiment or received 20, 50, 100, 200, 500 and 1000 micrograms Zn/rat and were killed 2 days after treatment in the dose-response experiment. It was suggested that ZnO particles were solubilized in the bronchoalveolar milieu and cleared from the lung with a half-life of 14 h. Metallothionein (MT) was induced with a peak at 2 days. The content of MT was proportional to the dose of ZnO, but contributed little for the accumulation of Zn in the lung. A dose of 20 micrograms Zn/rat was sufficient to develop maximum responses for beta-glucuronidase activity and surfactant content in the bronchoalveolar lavage fluid. Moreover, the activity of lactate dehydrogenase and protein content in the lavage fluid increased significantly at 20 micrograms Zn/rat. These results suggest that the recommended ZnO concentration in the work-place atmosphere of 5 mg/m3 might not be adequate.

Animals↗