Biomedical subjects

T Umeda

Publications and source records attributed to T Umeda.

420 records · Page 24Linked to original sources

PubMedDate not supplied

Secondary excision of choledochal cysts after previous cyst-enterostomies.

BACKGROUND/AIMS: Patients with a choledochal cyst previously treated by internal drainage should undergo secondary cyst excision. The results of such secondary excisions have not yet been reported. METHODOLOGY: Over a 27-year period, 121 patients underwent excision of a choledochal cyst at our hospitals. Of these, 14 patients underwent secondary cyst excision following internal drainage. These patients were compared retrospectively with the remaining 107 patients who underwent primary cyst excision. RESULTS: Blood loss and operative time were greater, and early and late post-operative complications were significantly more frequent in the secondary excision group. Wound infection (early complication), pancreatic stones (late complication), and hepatolithiasis (late complication) were significantly more common in the secondary excision group. Histologically, inflammation and biliary glands were more frequently seen in the resected bile ducts in the secondary excision group. CONCLUSIONS: The long-term results of secondary excision of choledochal cysts are worse than after primary excision. The frequent late complications may be related to the development of biliary glands as a consequence of cyst-enterostomy.

Adolescent↗

PubMedDate not supplied

Reciprocal changes in leptin and tumor necrosis factor-alpha with exercise in insulin resistant rats.

Leptin and tumor necrosis factor--alpha(TNF-alpha) are important mediators of insulin resistance in obese subjects through their over-expression in adipose tissue. Secretion of leptin into the circulation is a signal for the brain in patients with hyperinsulinemia. Regulation of TNF-alpha affects adipocyte insulin sensitivity and lipid accumulation. Exercise training has been suggested for the prevention and treatment of such disorders. However, how exercise modifies secretion of leptin and TNF-alpha is not known. We investigated leptin and TNF-alpha in a rat model of insulin resistance induced by sucrose. After 4 weeks of sucrose feeding, 4 weeks of voluntary wheel running significantly reduced the concentrations of leptin in mesenteric (MS) and subcutaneous fat (SC) when compared to sedentary sucrose-feeding rats. These results suggest that exercise controls cytokine regulation of leptin and TNF-alpha. The increased TNF-alpha in adipose tissue may activate cytolysis for energy consumption.

Adipocytes↗

PubMedDate not supplied

Evaluation of compressed lung CT image quality using quantitative analysis.

The goals of this study were (1) to evaluate the quality of compressed lung CT images obtained using high resolution CT (HRCT: 2 mm slice thickness) for degree of compression and conventional CT (10 mm slice thickness) images by using physical and subjective evaluations, and (2) to analyze the distortion of density distribution on lung CT images using histogram analysis for each compression ratio. The coding method was performed according to the Joint Photographic Experts Group (JPEG). We physically evaluated the quality of compressed lung CT images using the peak signal-to-noise ratio (PSNR) as given by the square root of the ratio of the peak value of the gray level squared to the mean square error (dB) and subjectively evaluated the CT images using the mean opinion score (MOS). The acceptable compression ratio for diagnosis was about 1:6 to 1:7 for conventional CT images and about 1:4 to 1:5 for HRCT images as determined by MOS. The PSNR corresponding to acceptable compression ratios was about 50 dB. The difference in density distribution between HRCT and conventional CT was statistically significant (Friedman test: p<0.02) in histogram analysis. Results suggested that, in comparison with conventional CT, a high compression ratio was not suitable for HRCT.

Algorithms↗

PubMedDate not supplied

Biliary excretion of diphenylhydantoin in the rat. Time-course studies.

The role of biliary excretion in the dose-dependent elimination of diphenylhydantoin (DPH) was investigated in the rat. During 6 hr, following iv injection of 10 mg of (14-C)DPH per kg, 28% of the radioactivity was excreted in bile and following the higher dose of DPH reached a plateau and remained constant over a period of 6 hr, whereas, with the lower dose, the excretion was a first order process (half-life 165 plus or minus 34 (SE) min). When the major metabolite of DPH,5-(P-hydroxyphenyl)-5-phenylhydantoin (P-HPPH, 14-C-labeled), was administered 1 and 10 mg/kg iv), the rates of biliary excretion of total radioactivity were first order, with half-lives of 49 plus or minus 3 and 57 plus or minus 4 min, respectively. Therefore, the conjugation of p-HPPH and the transfer of the conjugate from liver cells into bile were not saturable with the two doses studied. The data are consistent with the assumption that the dose-dependent elimination of DPH is due to the saturable conversion of DPH to p-HPPH.

Animals↗

PubMedDate not supplied

Effects of sevoflurane and halothane on reperfusion-induced arrhythmia in the isolated rat heart.

The effects of sevoflurane and halothane on reperfusion-induced arrhythmia in the isolated rat heart were examined. Reperfusion-induced ventricular fibrillation (VF) occurred in all rat hearts, and the duration of VF was 151 +/- 11 (mean +/- SEM) seconds in the control group (no anesthetics administered). Sevoflurane changed neither incidence nor duration of VF at 1, 2, and 3 minimum alveolar concentrations (MAC) of anesthetic. Halothane altered neither the incidence nor duration of VF compared with the control group at 1 MAC; however, at 2 and 3 MAC, halothane significantly reduced the incidence and duration of VF (P < 0.05 at 1, 2, and 3 MAC halothane: respective incidences were 100%, 18%, and 55% and respective durations, 82 +/- 27 seconds, 20 +/- 6 seconds, and 13 +/- 9 seconds). In the isolated rat heart, we found that halothane has antiarrhythmic effects against reperfusion-induced arrhythmia at 2 and 3 MAC. Sevoflurane, however, did not have any antiarrhythmic effects against reperfusion-induced arrhythmia at 1, 2, or 3 MAC.

Animals↗

PubMedDate not supplied

Phorbol ester induces differentiation of a human prostatic cancer cell line TSU-Pr1 into cells with characteristics of microglia.

The effects of various reagents on the induction of differentiation of the human prostatic cancer cell line, TSU-Pr1, were examined. Among these agents, the phorbol ester, TPA, almost completely suppressed cell proliferation at the concentration of 10(-8) M, and induced remarkable morphologic changes yielding cells with the microglial feature of an ameboid and/or ramified shape. More than 90% of the cells underwent the induction of morphologic changes by day 7 after treatment with 10(-8) M TPA. The expression of reliable microglial markers, alpha-naphthyl acetate esterase activity and CD11b, was observed in the differentiated cells. The data presented here suggest that TPA induces differentiation of a human prostate cancer cell line into cells with the characteristics of microglia.

Cell Differentiation↗