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Biomedical subjects

T Imai

Publications and source records attributed to T Imai.

At least 955 records · Page 53Linked to original sources
PubMed1983

Solid carcinomas of the stomach. A combined histochemical, light and electron microscopic study.

Twenty cases of solid carcinoma of the stomach (SCS) were studied light and electron microscopically and histochemically. On the histologic, histochemical, and ultrastructural bases they were divided into three subgroups: mucin-secreting carcinomas (MSC) (12 cases); neuroendocrine tumors (NET) (five cases); and composite tumors (CT) (three cases). Histochemically, mucin was detectable at high intensity in most cases of MSC and ultrastructurally, the mucin granules, the number of which varied considerably from cell to cell, showed prominent pleomorphism with varying degree of maturity. Uniformly round neuroendocrine granules were demonstrable in all of the NET cases and in two cases of CT. The argyrophilic stain was negative in two cases of NET, whereas it was positive in three cases of MSC. Thus, there was a discrepancy between the silver nitrate reduction intensity and the ultrastructural demonstrability of neuroendocrine granules. Histologically, combined occurrence of some nuclear palisading of basal cells and rosette-like arrangement without evident glandular formation was specific to NET and this provides a helpful basis for the light microscopic differentiation of this tumor from other type tumors.

Adult↗
PubMed1983

Cloning and sequence analysis of cDNA for human renin precursor.

The primary structure of human renin precursor has been deduced from its cDNA sequence. A library of cDNA clones was constructed from human kidney poly(A)+ RNA by applying the vector/primer method of Okayama and Berg. The library was screened for human renin sequences by hybridization with the previously cloned mouse renin cDNA. Of the 240,000 colonies screened, 35 colonies that were positive for hybridization were isolated. Two recombinant plasmids containing long inserts of about 1,300 and 1,600 base pairs were selected for sequence analysis. The amino acid sequence predicted from the cDNA sequence shows that the human renin precursor consists of 406 amino acids with a pre and a pro segment carrying 20 and 46 amino acids, respectively. A high degree of sequence homology was found upon comparison of the mouse and human renins. Close similarities were also observed in the primary structures of renin and aspartyl proteinases that have known three-dimensional structures, suggesting a similar tertiary structure for renin.

Amino Acid Sequence↗
PubMed1983

The effects of fluoride on cell growth of two human cell lines and on DNA and protein synthesis in HeLa cells.

The effect of sodium fluoride on the growth of two continuous human cell lines, i.e. HeLa cells and human conjunctiva clone 1-5C-4 cells, was studied. The growth of HeLa cells and clone 1-5C-4 cells was arrested nearly completely by the addition of 0.95 and 1,90 mM of sodium fluoride, respectively. DNA synthesis in HeLa cells, determined by incorporation of 3H-thymidine, was not affected appreciably for the first 24-hr period after the addition of sodium fluoride. Markedly reduced incorporation, however, occurred during the next 24-hr period. Thus, there was a discrepancy between the immediate cessation of cell division and the delayed suppression of DNA synthesis. On the other hand, a suppressive effect of sodium fluoride on protein synthesis determined by 14C-leucine incorporation was evident already during the first 24-hr period. The results indicate that the inhibition of protein synthesis is the main cause of growth inhibition.

Cell Division↗
PubMed1983

Enhancement of IgE antibody production by ovalbumin aerosol in mice.

The effect of aerosolized ovalbumin (OA) on the induction of IgE antibody production was investigated in BALB/c mice. Enhancement of anti-OA IgE antibody production was obtained after the administration of 10 micrograms OA in mice preexposed to 1% aerosolized OA for 6 or 30 min, and after the administration of 1 microgram OA in mice preexposed to aerosolized OA for 30 min. IgE antibody production could also be induced by preexposure to aerosolized OA at a concentration as low as 0.1%. A carrier effect was observed by preexposure to aerosolized OA using a hapten-carrier system. In the latter system, whole body irradiation (200 R) could not enhance IgE response, suggesting that irradiation-sensitive suppressor T cells might be generated in insufficient amount or not at all by aerosolized OA. Preexposure to aerosolized dinitrophenol-OA could not enhance anti-dinitrophenol IgE response. These results suggest that the exposure to aerosolized antigen primed preferentially T helper cells.

Aerosols↗
PubMed1983

Serial changes of complement titers in the acute phase of myocardial infarction.

Although some studies suggest the involvement of a complement activation in the development of acute myocardial infarction, there has been little convincing evidence of the change of the complement in patients suffering from myocardial infarction. In 11 patients with acute myocardial infarction the serial changes of the total hemolytic complement titer (CH50), C3, C4, total serum protein and C3 conversion were investigated up to 120 hours after its attack. The level of CH50 and C4 increased consistently in the acute phase of myocardial infarction, but C3 did not show any change and total serum protein declined after 96 hours. Beta 1 A globulin, the split product of C3, could not be detected in the blood stream. These results suggest that the infarcted or ischemic myocardium would activate complements, and C3 might be consumed continuously by the infarcted or ischemic myocardium. Such consumption of complements should stimulate the production of complement and would give rise of an increase in C4 and CH50. It is suggested that activated complement might play a significant role in the development of myocardial infarction.

Adult↗
PubMed1983

A solid phase radioimmunoassay for the detection of anti-insulin antibodies.

A solid phase radioimmunoassay for the detection of anti-insulin antibodies has been developed and evaluated. After coating round-bottomed wells of polyvinyl chloride with porcine monocomponent insulin, 50 microliters of serum from either insulin-treated diabetics or non diabetic controls was added to the wells, followed by the addition of 125I-protein A, and then the radioactivity of the bound 125I-protein A on the wells was counted. This solid phase radioimmunoassay is very simple, does not require centrifugal steps and the results correlated well with those of previously published immune precipitation methods (r = 0.68, p less than 0.01). Our present method requires only 50 microliters of serum and 4 hours for the assay, if the wells are coated with insulin in advance. Therefore, this procedure is thought to be suitable for clinical use.

Chemical Precipitation↗
PubMed1983

Cell-free translation of human renin mRNA.

The molecular weight of human renin precursor (preprorenin) was determined to be 43,000 by cell-free translation of its mRNA. Poly(A)+-containing RNA from human infarcted kidney was translated in a cell-free reticulocyte lysate system containing [35S] methionine. Immunoprecipitation with anti-renin antibody gave one major band with an apparent Mr = 43,000, as determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and fluorography. The specific band, which represents the prepro-form of human renal renin, was very similar to mouse submandibular gland preprorenin in its electrophoretic mobility.

Animals↗
PubMed1983

[Micrometastasis in the resected lungs of lung cancer patients with special reference to their clinical features].

The microscopic metastases were examined seemingly unaffected areas of the resected lungs in 116 primary lung cancer patients. In 55 patients (47%), micrometastases were found in the areas which looked normal. The investigation on the route and location of micrometastaes revealed that lung metastases were formed mainly through haematogenous and partly through lymphatic route. The high incidence of postoperative intrapulmonary spread in the positive micrometastasis group suggested that most of microscopic deposits would become distinct tumors in time. Thirteen patients have had a second operation for the intrapulmonary metastatic lesions. There was one postoperative death. Nine patients have subsequently died. Three patients are still alive and well without evidence of recurrence.

Adenocarcinoma↗
PubMed1982

[A case with Bartter's syndrome associated with type II hyperlipidemia, increased fluidity of plasma VLDL and abnormal configuration of peripheral erythrocytes (author's transl)].

A 34-year-old female complaining of numbness and weakness of the extremities was examined. Consanguineous marriage was contracted between mother and father. She was of short stature (149 cm), and her blood pressure was normal (118/60 mmHg). Her serum potassium concentration had decreased to a level between 2.5 and 3.2 mEq/L, and hypokalemic alkalosis was present. Potassium clearance had increased and urinary concentrating capacity was impaired. Plasma renin activity was high at 25 ng/ml/hr but plasma aldosterone concentration was normal. Hypertensive response to angiotensin II (50 ng/kg/min) was weak but improved to nearly the normal value after the administration of indomethacin for 17 days at a dose of 50 mg/day. A slight elevation in blood pressure was observed during the infusion of norepinephrine (250 ng/kg/min). A decrease in blood pressure was observed during the infusion of 1-sarcosine, 8-isoleucine angiotensin II (600 ng/kg/min) with concomitant increase of plasma renin activity. Twenty-four hour urinary excretion of prostaglandin E decreased somewhat (225 approximately 252 ng/day), and hyperplasia of the juxtaglomerular cells and increased JG index were demonstrated in the biopsy specimens of the right kidney. From the findings, the present case were diagnosed as Bartter's syndrome. Although mild enlargement of the sella turcica was found in skull x-ray films, no abnormalities in pituitary function were demonstrated. Other unusual complications, i.e. hyperlipidemia (type II, beta-dominant) and abnormal configuration of peripheral erythrocytes, were demonstrated. Phospholipid composition of the erythrocyte membrane was normal. The fluidity of plasma VLDL examined by electron spin resonance was increased. Hypokalemia and hyperreninemia were improved through the administration of indomethacin. However, because of headache as an adverse effect, further administration could not be accepted. The patient's complaints were resolved by the rectal application of indomethacin with oral administrations of spironolactone and triamterene. Changes in serum lipid levels did not occur with the above mentioned treatment. alpha-tocopheryl nicotinate lowered the levels of serum lipids and normalized the configuration of peripheral erythrocytes. But increased fluidity of plasma VLDL remained, and phospholipid composition of erythrocyte membrane was also unchanged. The relationship between the rare complications mentioned above and the pathophysiology of Bartter's syndrome is still obscure.

Adult↗
PubMed1982

Gastric carcinoma with psammomatous calcification: report of a case, with reference to calculogenesis.

A case of gastric adenocarcinoma with argyrophilic property and psammomatous calcification is reported. Histologically, the psammoma bodies are found most frequently within the glandular lumina. Electron microscopy, however, reveals that calcium first appears within the cytoplasm of tumor cells. Electron probe x-ray microanalysis demonstrates calcium and phosphorus in granular or floccular osmiophilic deposits found in intracytoplasmic electronlucent zones of tumor cells. By x-ray diffractometry, the calcium component is presumed to be hydroxyappatite (Ca5(PO4)3.(OH). The findings strongly support the view of the intracytoplasmic origin of psammomatous calcification. The tumor yielded a parathyroid hormone (PTH)-like substance, and a possible relationship between this substance and psammomatous calcification is spectulated.

Adenocarcinoma↗
PubMed1982

Enhanced oral bioavailability of antiinflammatory drug flurbiprofen in rabbits by tri-O-methyl-beta-cyclodextrin complexation.

Inclusion complex of antiinflammatory drug flurbiprofen with tri-O-methyl-beta-cyclodextrin in 1:1 molar ratio was prepared, and its dissolution and absorption characteristics were compared with those of flurbiprofen. The apparent dissolution rate of flurbiprofen in water was significantly increased by the inclusion complexation. The serum level of flurbiprofen following the oral administration of the complex to rabbits was higher than that of the drug alone. The enhanced bioavailability of flurbiprofen suggests the possible utility of tri-O-methyl-beta-cyclodextrin in pharmaceutical formulation.

Administration, Oral↗