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Biomedical subjects

T Imamura

Publications and source records attributed to T Imamura.

At least 487 records · Page 27Linked to original sources
PubMed1989

Disopyramide induces insulin secretion and plasma glucose diminution: studies using the in situ canine pancreas.

The mechanism of disopyramide-induced hypoglycemia, a life-threatening complication in the antiarrhythmic drug treatment, is still controversial. To elucidate this, we have evaluated plasma insulin (IRI) and glucagon (IRG) responses in the pancreatic vein (PV) of the in situ pancreas as well as responses of plasma IRI, IRG, and glucose in the femoral artery (FA) to disopyramide phosphate administration in anesthetized dogs. First, infusion of disopyramide at a dose of 50 mg for ten minutes directly into the pancreatic artery, but not the vehicle, increased significantly plasma IRI concentration in the PV (P less than .05 or less), where the IRI response started within three minutes and reached a peak of 2.8-fold preinfusion value at 30 minutes after starting the infusion (n = 7). Plasma IRI concentration in the FA also increased slightly but significantly (P less than .05). Plasma IRG concentration in the PV initially decreased significantly (P less than .05 or less) and in the FA at one point (P less than .05) during the infusion, and then increased significantly after cessation of the infusion, showing a peak of 1.9-fold preinfusion value at 60 minutes in the PV and the FA (P less than .05). Plasma glucose concentration in the FA decreased slowly and significantly after the infusion (P less than .05 or less) and fell by 16% of the baseline value at 60 minutes (P less than .05). Second, serum disopyramide concentration of 13.7 +/- 2.8 micrograms/mL at ten minutes, which corresponds to a twofold to threefold concentration of the human therapeutic level (n = 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Spontaneous regression of primary malignant lymphoma of the stomach in two nontreated Japanese.

Two patients with primary malignant lymphoma underwent spontaneous regression. One was a 40-year-old woman with a large ulcerating tumor on the greater curvature of the gastric antrum. This tumor shrank spontaneously, leaving only a small shallow ulcer. The resected specimen showed a minute focus of malignant lymphoma in the ulcer base. The other was a 73-year-old man who had a tumor with central ulceration on the posterior wall of the gastric antrum. Endoscopic biopsy revealed a malignant lymphoma. This tumor disappeared 60 days later. The patient refused surgery and remains well with no evidence of recurrent disease at this writing, 44 months later. Although there have been several case reports of spontaneous regression, partial or complete, of gastric malignant lymphoma, our cases seem to be the ones best proven.

Adult↗
PubMed1989

[A case of infective endocarditis (IE) improving with orally administered amoxicillin (AMPC)].

Progress in chemotherapy and cardiosurgery has remarkably decreased the mortality due to infective endocarditis (IE) in recent years. In chemotherapy for IE, parental administration of antibiotics has been used routinely, the patients suffer from the psychological and physiological burden due to frequent injections and long period of therapy, even though the therapy for IE is successful. In this report, we present a case of IE caused by S. mitis, which was remarkably improved by oral administration of AMPC. A case, 69. y.o. female. She felt like a common cold and visited a G.P. Cardiomegaly was pointed out and positive inflammatory findings in serological examination were found. A low grade fever continued, and she was admitted to the hospital. Blood cultures were positive for S. mitis. For further examination, she was transferred to the university hospital. Based on the extensive blood cultures and cardioechogram, she was diagnosed IE caused by S. mitis. Because there were no symptoms of heart failure, we decided to try oral administration of AMPC, 4 g/day or 6 g/day at an interval of 6 hours. On the second day of therapy, the blood culture turned to be negative for pathogens, and on the fourth day body temperature became normal. On about the 60th day, the CRP finding became negative. Concentrations in the serum of AMPC were more than 10 folds of AMPC-MIC (0.5 microgram/ml) for S. mitis. The patient, however, suffer from complications of lung embolism and was operated for exchange of heart valves. After surgery, she has been well without any symptoms from IE.

Administration, Oral↗
PubMed1989

[Molecular aspects of human hepatocellular carcinoma].

It is now evident that development of hepatocellular carcinoma (HCC) in human is associated with a long series of cellular and tissue changes that precede the ultimate development of the cancer. During recent years, enormous progress in molecular research on HCC has been made, particularly in the area of integration of HBV DNA to host cell and oncogene association with carcinogenicity. A high ratio of HCCs from patients in endemic area has integrated HBV DNA in cellular DNA and in some cases, chromosomal translocations associated with HBV integration were observed, suggesting that the integration or the results thereof are connected with cancer development. Employing a DNA-mediated transfection assay using NIH3T3 mouse fibroblasts with high molecular weight DNA, we detected three cellular transforming genes (lca, N-ras, hst) in primary human HCC. However, little is known as to the linkage between the activation of these genes and liver carcinogenesis. In most human primary HCC tissues, at least two oncogenes, c-myc and N-ras are overexpressed, while in some cases other oncogenes c-fos or lca are overexpressed. It is likely that multiple c-oncogens are important in HCC, but specific transcripts for the malignancy of HCC were not detected. At present, we could not find any relationship between the expression of c-oncogenes and integration of HBV, serological markers or the degree of differentiation. Of the experimental animals most frequently used for studies of liver cancer, the rat is best understood and mimics closely many of the lesions in humans. It is of interest to consider that the identification and elucidation of the mechanisms underlying carcinogenic processes in the rat may offer testable hypotheses for steps in the human.

Adult↗
PubMed1989

[Surgical management of pulmonary metastasis from carcinoma of the uterine cervix].

The present study was designed to evaluate the efficacy of surgical management of pulmonary metastasis from carcinoma of the uterine cervix. We saw 609 cases of carcinoma of the uterine cervix from 1979 to 1987, and during the same period also saw 110 cases of recurrent carcinoma of the uterine cervix. Fourteen of these 110 cases were identified as having pulmonary metastasis, and in 11 of 14 cases the recurrent tumors were limited to the lung. Seven of these 11 cases underwent pulmonary resection. Six of the 7 survived more than 2 years after pulmonary resection. Among them, 1 patient has survived more than 4 years, and 1 patient more than 8 years. The tumor cells were thought to metastasize to the lung through the vertebral venous plexus (Batson's plexus) which was suggested as a metastatic route by Thomford et al. in their report on recurrent colon cancer. As a result of this study, if the recurrent tumor is clinically limited to the lung in patients with recurrent carcinoma of the uterine cervix, they should be treated by surgical resection of the pulmonary tumor.

Adenocarcinoma↗
PubMed1989

[Four cases of myocardial sarcoidosis].

We reported 4 cases diagnosed as myocardial sarcoidosis. One of them was diagnosed by endomyocardial biopsy, however, the others were diagnosed by cardiological findings and biopsy of the scalene node, liver or skin. Analysis of ECG findings showed conduction disturbances in all cases and disorders of impulse formation in two. Thallium 201 myocardial perfusion scans (T1 scan) revealed inferior and anteroseptal wall defects in case 4 and entire heterogenous defect in case 2. And also in case 2, left ventricular perfusion defect detected in T1 scan before steroid therapy changed to entire heterogenous defect. Thus, T1 scan was thought to be useful for the evaluation of therapy and for follow up study of myocardial sarcoidosis. In the cardiac echogram, thickening of the wall was seen in cases 3 and 4, and dilated ventricle in another case. Steroid was given in all cases and a pacemaker was implanted in two cases. The therapy was effective in all cases and ECG abnormalities were improved. In one case (Case 3) treated by a pacemaker steroid administration was halted and subsequently developed heart failure, but the other (Case 1) continued treatment with steroid caused return to a natural beat. Thus steroid therapy with a pacemaker implantation was considered to be effective for severe myocardial sarcoidosis.

Adult↗
PubMed1989

[Survey on oral and maxillofacial injuries in contact sports and diffusion of mouthguards].

Recent reports have shown an increase of oral and maxillofacial injuries caused by sports activities. In European and American countries, mouthguards are the popular measure against these injuries. The purpose of this study was to survey the rate of incidence of oral and maxillofacial injuries caused by contact sports, the diffusion and the evaluation of mouthguards and the interest in mouthguards in Japan. Questionnaires were sent to 244 Rugby football teams in Aichi prefecture and 27 American football teams in the Tokai area. We received replies from 153 Rugby football teams and 17 American football teams, and the results were as follows: 1) The rate of incidence of oral and maxillofacial injuries was 239 players out of 4721 players, which means 5.1% in Rugby football and 22 players out of 428 players, which means 5.1% in American football. 2) The diffusion of mouthguards was 20 out of 153 teams in Rugby football and 16 out of 17 teams in American football. And most of them are using commercially available mouthguards. 3) Almost all teams were not satisfied with their mouthguards and complained of speaking difficulties, discomfort and easy dislocation. 4) Almost all teams desire the improvement of mouthguards. 5) Teams with no experience of mouthguards were very much interested in the use of mouthguards but they do not have enough information about mouthguards. 6) We have to enlighten players and their instructors about mouthguards and diffuse the use of mouthguards more positively to contact sports players.

Adolescent↗
PubMed1989

[A case of stromal sarcoma of the breast].

A 28-year-old woman with a stromal sarcoma of the breast is reported. By palpation, she had uncovered a tumor in the upper inner quadrant of the right breast. The subsequent physical examination and echographic findings suggested a phyllodes tumor and an excisional biopsy was performed. A pathologic examination revealed the infiltration of spindle cells with a fascicular pattern, a bizarre mitotic configuration and no epithelial component, thus leading to the diagnosis of a stromal sarcoma. The patient then underwent a modified radical mastectomy. A stomal sarcoma of the breast is very rare, and early diagnosis and a curative resection improves the chances of survival.

Adult↗
PubMed1988

Sensitive determination of diazepam and N-desmethyldiazepam in human material using capillary gas chromatography-mass spectrometry.

A reliable and sensitive capillary gas chromatographic-mass spectrometric method was developed for the detection and determination of diazepam and its major metabolite, N-desmethyldiazepam, in human material. Medazepam served as the internal standard. Quantitative determination was achieved using mass fragmentography with selected ions of m/z 256 for diazepam and m/z 242 for N-desmethyldiazepam and medazepam. The limit of detection was 1 ng/g and the recoveries were 98.54 +/- 3.95% for diazepam and 98.66 +/- 6.48% for N-desmethyldiazepam. The calibration graph was linear over the concentration range from 1.0 ng/g to 1.0 microgram/g for diazepam and N-desmethyldiazepam. Using this method, trace amounts of diazepam and N-desmethyldiazepam were detected in the tissues of an autopsied individual.

Aged↗
PubMed1988

Purification of basic FGF receptors from rat brain.

Receptor molecules for basic fibroblast growth factor (bFGF) were isolated from rat brain by a novel and rapid procedure and characterized. Purification was performed by wheatgerm agglutinin (WGA) gel affinity chromatography in combination with bFGF gel affinity chromatography, utilizing a novel elution method involving heparin. The eluted proteins were active in binding bFGF and were separated as two bands with respective molecular masses of 140 kDa and 110 kDa on SDS-PAGE. More than half of this bFGF-binding activity was lost after 16 h at 4 degrees C. Thus, bFGF receptors were purified as labile glycoconjugates.

Animals↗
PubMed1988

Homogeneous immunoassay based on dihexadecyl-dimethylammonium bilayer membranes.

We describe a rapid, highly sensitive, simple immunoassay based on cationic bilayer membranes prepared from dihexadecyl-dimethylammonium bromide. This detergent was dispersed in water to give a slightly turbid solution which contained lamellar (not vesicular) bilayer membranes with a gel to liquid crystal phase transition (Tc, 28 degrees C). An anionic hapten (N,N'-bis(2,4-dinitrophenyl)-L-lysine) combined electrostatically with this cationic membrane to induce aggregation of membranes, making the solution turbid. This aggregation was suppressed by antibodies to the hapten. The aggregation rate was rapid at a temperature above Tc, and the amount of antibodies was quantified by measuring absorbance or light scattering of the aqueous solution with a detection limit of 0.1 ng/ml of the antibodies. Anionic and zwitterionic bilayer membranes from di(tetradecyl)phosphate and phosphocholine derivatives, respectively, were less sensitive as detectors of the hapten-antibody reaction. Ionic interactions between cationic bilayer membranes and anionic haptens are important for successful assay performance.

Agglutination↗
PubMed1988

A novel growth factor in rat spleen which promotes proliferation of hepatocytes in primary culture.

We have identified a factor from adult rat spleen which stimulates the proliferation of rat hepatocytes. The activity was found in the spleen soluble matrix fraction (1,300xg supernatant of inter-cellular fraction). No activity was found in the spleen cell homogenate, in the spleen insoluble matrix fraction or rat serum. After 4 days of incubation with the spleen factor, the cell number increased 4-fold higher than that at inoculation. The growth stimulation were observed in both fetal bovine serum supplemented medium and hormonally defined medium which contains insulin, epidermal growth factor, glucagon, growth hormone and prolactin. The level of activity in the spleen soluble matrix was not affected by partial hepatectomy or trypsinization. These data indicate that the spleen factor is different from previously characterized effectors of hepatocyte proliferation. The novel factor has been named spleen derived growth factor (SDGF).

Animals↗
PubMed1988

Pulmonary endothelial and alveolar epithelial lesions induced by O,O,S-trimethyl phosphorothioate in rats.

The morphogenesis of pulmonary injury induced by an impurity present in a commercially important organophosphorus insecticide, O,O,S-trimethyl phosphorothioate (OOS-TMP), was studied by combined light and transmission electron microscopy. Weanling female WAG/Rij rats received OOS-TMP dissolved in corn oil by gavage and were studied at intervals from 6 to 168 h after treatment. Sequestration of neutrophils was initially observed at 12 h after treatment and was accompanied by interstitial oedema. Plasmalemma alterations in endothelium lining capillaries and small arteries and veins were observed from 12 to 120 h after treatment and were accompanied by endothelial cell detachment and separation from the basal lamina. Abundant aggregates of fibrin were sequentially observed in intravascular, interstitial, and alveolar spaces. Platelet aggregation and degranulation were occasionally observed in capillaries as early as 12 h after treatment, and frequently observed in capillaries and small vessels from 24 to 96 h after treatment. Significant increases in wet lung weight and lung water content occurred at the same time that morphologic changes were observed in pulmonary endothelium. Alterations in type I alveolar epithelial cells were initially observed at 24 h after treatment. Cell swelling, fragmentation, and necrosis were observed in both type I and type II cells and resulted in a bare basal lamina. Marked attenuation, hypertrophy, and proliferation of type II epithelial cells followed alveolar epithelial cell injury and loss. Minimal changes were observed in non-ciliated bronchiolar epithelial (Clara) cells; predominant changes included the loss of surface microvilli and apical cytoplasmic bulge. The results of this study indicate that the endothelium and alveolar epithelium are the predominant cell types in the rat lung injured following OOS-TMP administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Antecedent chronic hyperglycaemia blocks phlorizin-induced insulin resistance in the dog.

Hyperglycaemia may enhance insulin resistance typical of non-insulin dependent diabetes mellitus, as well as insulin dependent diabetes mellitus, and thus initiate a vicious pathogenetic cycle. We sought to test the hypothesis that reduction in chronic hyperglycaemia in the diabetic dog by methods that do not employ insulin may improve insulin resistance. We used the glucuretic agent phlorizin in dogs rendered chronically hyperglycaemic and diabetic by alloxan treatment. To analyse glucose disposition the euglycaemic clamp was performed. To minimize the role of counterregulatory influences that might be at play when glucose is reduced, the hyperglycaemic clamp with continuous somatostatin infusion was performed. Although phlorizin normalised plasma glucose in the diabetic dog and reduced plasma glucose in normal, non-diabetic dogs, insulin dependent glucose disposition rate did not improve. While phlorizin itself was associated with insulin resistance in the normal animals, the insulin resistance of diabetes mellitus was not further augmented. We conclude that phlorizin is associated with insulin resistance perhaps by a common pathway shared by chronic hyperglycaemia. Care must be taken when phlorizin is used as an agent to study glucose disposition.

Animals↗
PubMed1988

Neonatal death and lung injury in rats caused by intrauterine exposure to O,O,S-trimethylphosphorothioate.

O,O,S-Trimethyl phosphorothioate (OOS-TMP) is an impurity present in a number of widely used organophosphorus insecticides and has been recognized as a potent lung toxicant. OOS-TMP was given p.o. to pregnant rats on gestation day (G) 20 at 0.5, 2.5, 10 and 40 mg/kg. Control dams or pair-fed dams (pair-fed to 40 mg/kg) received 2 ml/kg corn oil. Neonates from treated dams died within 72 h after delivery in a dose-related manner: 100% at 40 mg/kg, 86% at 10 mg/kg, 15% at 2.5 mg/kg, 1% at 0.5 mg/kg, with 3% in controls and 2% in neonates from pair-fed dams. Neonates from treated (40 or 10 mg/kg) and control dams were cross-fostered. The cross-fostering did not affect mortality of neonates from either dosed dams or from control dams. Disposition of OOS-TMP was studied by using [3H]-OOS-TMP at 0.5, 2.5 and 10 mg/kg. Concentrations of OOS-TMP equivalent in fetal lung were about one half of those in mothers at all doses. In another set of experiments, dams (five dams for each dose) were dosed on G 20 with OOS-TMP p.o. at 0, 0.5, 2.5, 10, and 40 mg/kg or pair-fed (pair-fed to 40 mg/kg) and the fetuses were delivered by cesarean section (C-section) on G 23. In neonates from dams dosed with 10 and 40 mg/kg, cyanosis occurred within 4 h after C-section. Histopathological examination revealed dose-related proliferation of type II pneumocytes in dams and proliferation of interstitial cells and delayed septal/capillary development in neonates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

A substitution of cytosine for thymine in codon 110 of the human beta-globin gene is a novel cause of beta-thalassemia phenotypes.

We have described a novel human globin gene mutation that produced in a Japanese family the beta-thalassemia phenotype through a post-translational mechanism. Substitution of proline for leucine at position 110 in the G-helix of the beta-globin chain greatly reduced the molecular stability of the beta-globin subunit, leading to total destruction of the variant globin chains by proteolysis and hence to the beta-thalassemia phenotype. The mutation could be identified after MspI digestion. This detection of the mutation on the gene level is valuable for diagnostic purposes.

Amino Acid Sequence↗