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Biomedical subjects

T Shibata

Publications and source records attributed to T Shibata.

At least 1,243 records · Page 69Linked to original sources

Spectrum of CT findings in pediatric patients after partial liver transplantation.

Liver transplantation is an accepted therapy for patients with severe liver diseases. In pediatric liver transplantation, the application of reduced-size and split-liver transplantation has expanded the donor pool. The development of living related donor partial liver transplantation has further increased the availability of donors. Complications in patients after living related transplantation include hepatic arterial thrombosis, portal venous stenosis and thrombosis, hepatic venous stenosis, biliary stenosis or leak, biloma formation, fatty liver, extrahepatic fluid collection, posttransplantation lymphoproliferative disorder, and organ rejection. Ultrasonography is the primary imaging modality for evaluation of the vascular system of patients after liver transplantation, and computed tomography is useful to help diagnose hepatic parenchymal abnormalities including infarction, congestion, and fatty change; intrahepatic biliary damage; and extrahepatic disorders, including abnormal fluid collections, varicose veins, and lymphadenopathy.

Child↗

Inhibitory effects of malotilate on in vitro invasion of lung endothelial cell monolayer by human oral squamous cell carcinoma cells.

We have previously reported that malotilate (MT) inhibited the invasion and metastasis of rat mammary carcinoma cells through the modification of host endothelial cells. In this study, we examined the inhibitory effects of MT on invasion of human cancer, using five oral squamous cell carcinoma cells (SAS, Ca9-22 and HSC-2, -3 and -4). MT did not affect the growth of these tumor cells and the invasion of reconstituted basement membrane, Matrigel. In an in vitro invasion assay using rat lung endothelial (RLE) cells, invasion of tumor cells which had been treated with MT (10 ng/ml, 24 h) was not affected; however, when RLE cells had been treated with MT, invasion was significantly inhibited in three cell lines (SAS, Ca9-22 and HSC-4) and a tendency to inhibition was also observed in other cell lines. Electron-microscopical examination of the RLE monolayer treated with MT (MT-RLE) showed the development of gap and tight junction-like structures. Subsequently, junction-associated proteins, connexin 43, zonula occludin and desmoglein, were examined by Western blotting. Protein levels of connexin 43 and zonula occludin were elevated dose dependently, and connexin 43 was chronologically enhanced by MT whereas desmoglein was not. The enhanced gap junctional communication of MT-RLE cells was observed in the scrape-loading assay using lucifer yellow CH. These results suggest that MT promotes the development of cell-to-cell adhesion, e. g. gap junction and tight junction in endothelial cells, resulting in the inhibition of invasion by the tumor cells.

Animals↗

Fluoride intake in Japanese children aged 3-5 years by the duplicate-diet technique.

This study was conducted to determine the fluoride intakes in 94 preschool children aged 3, 4 and 5 (n = 30, 30, 34, respectively) residing in Yokkaichi, Mie Prefecture (< 0.16 ppm F water supply). The parents duplicated all the diets that their children ingested on 3 separate days during a 1-year period. The acid-diffusible fluoride in the diet was isolated by the acid-diffusion technique and measured with a fluoride electrode. The mean daily fluoride intakes from diet alone by children aged 3, 4 and 5 were 0.30 mg (n = 29, SD 0.19), 0.28 mg (n = 30, SD 0.19) and 0.30 mg (n = 34, SD 0.19), respectively. The total estimated mean values from diet and dentifrice were 0.35 mg (n = 29, SD 0.22, range 0.13-1.00), 0.33 mg (n = 30, SD 0.19, range 0.13-0.86) and 0.39 mg (n = 34, SD 0.18, range 0.18-1.01), respectively. It was concluded that the mean (+/-SD) total fluoride from diet and dentifrice in 3- to 5-year-old Japanese children was 0.35 +/- 0.19 mg/day (0.021 +/- 0.012 mg/kg body weight).

Analysis of Variance↗

Intra-oral fluoride retention 3 minutes after fluoride mouthrinsing in 4- to 5-year-old children: effects of fluoride concentration and rinsing time.

This study was undertaken to explore the site-specific retention rate and the possibility of shortening fluoride (F) mouthrinsing time of kindergarten children. Fluoride retention after 10-, 20- and 30-second mouthrinsing was determined in 43 kindergarten children aged 4-5 years. Tooth surfaces were sampled by a paper point method. Fluoride concentrations in the salivary film on tooth surfaces increased from primary molars to primary incisors in the maxilla and decreased from primary molars to primary incisors in the mandible. The fluoride solution reached the primary molars even after a 10-second rinse, but F concentrations were higher after 20 s than after 10 s and significantly higher after 30 s than after 10 s. No significant difference was observed between 20 and 30 s. The average total F retained in the mouth was 0.13 mg after 20 s and 0.17 mg after 30 s. It was concluded that 30-second mouthrinsing, which is used extensively in Japanese kindergartens, can be shortened to 20 s.

Analysis of Variance↗

Pseudocoarctation of the aorta--a case report.

We report a case of a 43-year-old woman with pseudocoarctation of the aorta manifested by a superior mediastinal mass on the chest roentgenogram. Evaluation was made using computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). No other congenital anomalies or aneurysms below the kinked area of the aorta could be found. The characteristic "kink" of the aorta and the absence of true coarctation were evident in the sagittal plane by MRI. MRI is of great value for examining disorders of the aorta.

Adult↗

The effect of ozone and photochemical oxidants on the interferon production by tonsillar lymphocytes.

In order to elucidate the biological effects of photochemical smog on the tonsil, lymphocytes from human tonsil were exposed to ozone and rabbits were exposed to ozone or photochemical oxidants. The tonsillar lymphocytes were studied for interferon production by Newcastle disease virus and blastoid transformation by PHA. Both interferon production by and blastoid transformation of the human tonsillar lymphocytes decreased markedly on exposure to ozone. Tonsillar lymphocytes from rabbits exposed to photochemical oxidants showed a significant decrease in interferon production. The decrease in interferon production in tonsillar lymphocytes from the rabbit exposed to photochemical oxidants was greater in magnitude than the decrease in interferon production in tonsillar lymphocytes exposed to ozone or non-irradiated automobile exhaust gas. The difference in blastoid transformation between the exposed groups and controls was not significnat. The results suggest that exposure to photochemical oxidants causes some functional changes in tonsillar lymphocytes.

Animals↗

Development of intra-arterial hyperthermia using a dextran-magnetite complex.

Dextran-magnetite complex (DM) is a colloidal sol of subdomain magnetite particles (i.e. a 'magnetic fluid'). The specific absorption rate of DM in an AC magnetic field is much higher than those of multidomain ferrite particles due to its different mechanism of heat generation. We designed two DM-containing embolic materials (a DM/Lipiodol emulsion and a DM/degradable starch microsphere suspension) to heat target tissues with the use of an external AC magnetic field. In vitro experiments showed that the heat-generating capacity of DM was not reduced in these mixtures. When these materials were injected into the renal arteries of Japanese white rabbits, they both achieved embolization of the artery and selective heating of the embolized kidney by exposure to a 100 kHz AC magnetic field of approximately 15,000 A/m. Histological examination showed a homogeneous distribution of DM in the embolized kidney. These results suggest the possibility of using DM-containing embolic materials for inductive hyperthermia.

Animals↗

Unsaturated fatty acid feeding prevents the development of acute hepatitis in Long-Evans cinnamon (LEC) rats.

To investigate the effects of dietary alpha-linolenic acid (18:3, n-3; alpha-LNA) and linoleic acid (18:2, n-6; LA) on the development of hereditary hepatitis, we compared incidences and grades of acute hepatitis between the Long-Evans cinnamon (LEC) rats fed with safflower oil-supplemented diet and perilla oil-supplemented diet. Both safflower and perilla oil supplemented diets reduced the incidence of hepatitis and significantly prolonged its onset as compared to the non-supplemented conventional diet. No significant difference was observed between safflower and perilla oil diets in the rats of incidence of hepatitis. At the age of 16 weeks, just before the onset of hepatitis, serum levels of transaminase (AST, ALT) and concentration of copper in rats fed with both test diets were significantly reduced as compared with that of rats fed alpha-linolenate and linoleate have an inhibitory effect on the development of hepatitis in LEC rats due to the prevention of serum copper elevation.

Acute Disease↗

Percutaneous ethanol injection for hepatocellular carcinoma originating in the caudate lobe.

BACKGROUND/AIMS: Hepatocellular carcinoma originating in the caudate lobe is rare and the treatments for caudate hepatocellular carcinoma were thought difficult, because of its unique location at hepatic resection, or because of complex arterial supply at transcatheter arterial embolization. Percutaneous ethanol injection is an effective treatment for small hepatocellular carcinoma. The aim of this study was to assess the efficacy of percutaneous ethanol injection for hepatocellular carcinoma originating in the caudate lobe. METHODOLOGY: During the past 4 years, 7 patients with 7 hepatocellular carcinomas originating in the caudate lobe underwent percutaneous ethanol injection as a curative treatment. The outcomes of percutaneous ethanol injection and the survival of the 7 patients were evaluated. RESULTS: Percutaneous ethanol injection was successfully carried out with no severe complications in all patients. During follow-up periods local recurrence was noticed in a patient, that was treated with percutaneous ethanol injection again. Four patients had recurrence in other parts of the liver, who were treated with percutaneous ethanol injection alone or percutaneous ethanol injection and transcatheter arterial embolization. Six patients were alive for 12-55 months after percutaneous ethanol injection and 1 patient died of hepatic failure 15 months after the procedure. CONCLUSIONS: Percutaneous ethanol injection was a safe and effective treatment, and it would be an alternative therapy for hepatocellular carcinoma originating in the caudate lobe.

Aged↗

Evaluation of several saccharides as osmotic agent for peritoneal dialysate.

OBJECTIVE: The carbonyl group of glucose reacts non-enzymatically with the amino group of protein to form advanced glycosylation end-products (AGEs). AGEs are found in the peritoneum of continuous ambulatory peritoneal dialysis patients, and this AGE formation is suspected to be one of the causes of impaired peritoneal function. In order to control AGE formation in the peritoneum, AGE formation and ultrafiltration in rats were examined with peritoneal dialysates using as osmotic agents saccharides that lack a carbonyl group, the saccharic acid lactobionate [molecular weight (MW) 358.30], the sugar alcohol maltitol (MW 344.32), and the nonreducing sugar nistose (MW 666.58). DESIGN: Bovine serum albumin (BSA) (25 mg/mL) was incubated with 18, 36, and 72 mg/mL maltitol, lactobionate, nistose, and glucose at 37 degrees C. After 3 or 6 weeks, amounts of furosine and N-(carboxymethyl) lysine were measured. A 20-mL intraperitoneal injection of a lactate-based dialysate (osmotic pressure 388 mOsm/kg) containing 4.34% maltitol, 4.52% lactobionate, or 8.4% nistose was given to Sprague-Dawley rats and, after 2, 4, or 6 hours, the quantity of effluent and levels of urea nitrogen and creatinine in the effluent and in serum were measured. RESULTS: No increases in furosine or N-(carboxymethyl) lysine were seen with maltitol, lactobionate, or nistose after 3 and 6 weeks of incubation with BSA; AGE formation was not observed. In the study in rats, the quantity of abdominal fluid after a 6-hour dwell was nistose > lactobionate > maltitol > glucose. No differences in dialysate-to-plasma ratios for urea nitrogen or creatinine were seen in any group. CONCLUSIONS: AGE formation in peritoneal tissue might be controlled by using saccharides with a modified carbonyl group as osmotic agents for peritoneal dialysates. Nistose is considered to yield the most efficient dialysis.

Animals↗

Transduction of thymidine phosphorylase cDNA facilitates efficacy of cytosine deaminase/5-FC gene therapy for malignant brain tumor.

The in vivo gene delivery of E. coli cytosine deaminase (cd) cDNA and systemic 5-fluorocytosine (5-FC) administration have been studied extensively because of their clinical relevance to cancer gene therapy. This approach has the potent advantage of a stronger bystander effect compared to the previous thymidine kinase suicide gene system of the herpes simplex virus. However, 5-fluorouracil (5-FU), an active metabolite in cd with 5-FC therapy, is not always effective for every type of tumor since the enzymes responsible for further drug metabolism vary significantly in each tissue. In this study, we aimed to increase the sensitivity of 5-FU by transduction of thymidine phosphorylase (dThdPase) cDNA into brain tumor cells. After retroviral transfer of the cDNA, we obtained 9L murine gliosarcoma cells showing stable expression of the target enzyme (9L-dThdPase). The growth of the cells was identical to wild type (9L-WT) or control-vector transfected (9L-Neo) cells in vitro. Sensitivity to 5-FU was increased in 9L-dThdPase cells. After the adenoviral delivery of cytosine deaminase gene into these cells, 9L-dThdPase cells also demonstrated an increased sensitivity to 5-FC. Moreover, we showed that transduction of dThdPase cDNA prolongs the survival of animals bearing intracerebral tumors after experimental in vivo cytosine deaminase gene therapy. These results suggest that transduction of thymidine phosphorylase may be a beneficial approach to increasing the efficacy of cd/5-FC suicide gene therapy in certain types of tumor.

Adenoviridae↗

Beneficial effect of fluorocarbon reperfusion on postoperative cardiac dysfunction of transplanted heart.

Fluosol DA 20% (Fluosol) perfusion was used to protect ischemic donor hearts of mongrel dogs from reperfusion injury. Fifteen orthotopically transplanted hearts, eight in the control group and seven in the Fluosol group, were studied for 3 hours after weaning from cardiopulmonary bypass. Donor hearts were arrested and immersed in 4 degrees C St. Thomas's Hospital Solution for 4 hours. The mean total ischemic time was 323 minutes (range, 298 to 345 minutes). In the Fluosol group, 200 ml of oxygenated Fluosol (37 degrees C; PO2 650 mm Hg; PCO2 35 mm Hg) was infused into the aortic root at approximately 100 ml/min just before aortic unclamping. Coronary sinus blood was analyzed for the MB fraction of creatine kinase, reduced glutathione, and oxidized glutathione. Hemodynamic and biochemical results were obtained at 30 minutes, 1 hour, and 3 hours after bypass. In the control group, during the second 30 minutes of the period after bypass, left ventricular end-diastolic pressure and stroke volume showed progressive deterioration, 54.8% increased (p less than 0.01) and 28.4% decreased (p less than 0.05), respectively. The MB fraction of creatine kinase and oxidized glutathione were increased, and reduced glutathione had declined, from 39.3 to 135.3 IU/L (p less than 0.01), from 28.0 to 33.4 micrograms/ml (p less than 0.05) and from 4.4 to 2.5 micrograms/ml (p less than 0.01), respectively. These parameters failed to recover during the next 2 hours, and massive mitochondrial degeneration was observed by electron microscopy. In the Fluosol group, these parameters maintained their baseline values, and electron microscopy showed well-preserved mitochondria. The data suggested that, in the control group, initial mitochondrial dysfunction was profound, persistent for at least 3 hours, and associated with membrane hyperpermeability, leading to cardiac dysfunction. Oxygenated Fluosol perfusion better preserved cardiac and mitochondrial function.

Animals↗

Primary intracardiac tumors in magnetic resonance imaging.

Fifteen patients suspected of having 18 intracardiac masses by two-dimensional echocardiography underwent MR imaging. In MR imaging, intracardiac masses were evaluated on both short TE (TE = 20-35 msec) and long TE (TE = 50-80 msec) spin echo sequences, and were differentiated from myocardium or papillary muscle. Three masses were excluded (they were papillary muscle) by MR imaging, and three were additionally found in patients with tuberous sclerosis. Fifteen masses were found by both echocardiography and MR imaging, one of which was stagnant blood. Cine MR imaging was needed to differentiate between thrombus and stagnant blood. MR imaging is useful for the evaluation of intracardiac masses. It is recommended in addition to echocardiography when cardiac tumors are suspected, especially in patients with tuberous sclerosis.

Adolescent↗

Computed tomography and angiogram of primary hepatic rhabdomyosarcoma: report of two adult cases.

Two adult cases of primary hepatic rhabdomyosarcoma, one of which was associated with hepatocellular carcinoma and had double malignant tumors, are described with emphasis on the radiologic features. On precontrast computed tomography, the lesion appeared as a well-defined hypodense mass like an abscess, while linear mottled enhancement was observed on the postcontrast scan. Angiography revealed displacement of the hepatic arteries and portal veins, irregular neovascularity in the peripheral portion, and scant tumor stain without dilatation of the feeding artery. Review of the literature revealed only 10 previous reports.

Aged↗

Mycotic aneurysm.

Mycotic aneurysms must be diagnosed rapidly because of the high mortality, associated with them. X-ray computed tomography (X-CT) is a noninvasive modality. Intravenous digital subtraction angiography (IVDSA) is also much less invasive and less dangerous than arteriography, especially in mycotic aneurysms, whose wall is thin. We describe two patients with mycotic aneurysms diagnosed by X-CT and IVDSA.

Aged↗

Comparison of image quality and portal vein visualization in IADSP using iopamidol, 76% urografin, and 38% urografin.

The image quality of intra-arterial digital subtraction portography (IADSP) was studied in 50 randomly assigned patients using one of three contrast agents: iopamidol, (IOP, 20 cases), 76% Na-meglumine diatrizoate (76% UG, 20 cases), and 38% Na-meglumine diatrizoate (38% UG, 10 cases). Sharpness and contrast of images, and portal vein visualization were evaluated in these groups. IOP provided better image quality and portal vein visualization than 76% UG. There was no significant difference between them in terms of side effects, such as contrast medium-induced pain and feeling of warmth, or changes in physiological parameters like blood pressure and heart rate. When a low osmolar contrast agent like IOP passes through the mesentery capillary bed, the eflux of the contrast agent into the interstitial space and the influx of water into the capillary may be less, resulting in less dilution of the contrast agent in the superior mesenteric vein. This might explain the better image quality and portal vein visualization of IOP.

Diatrizoate Meglumine↗

Possible function of the cytoplasmic axial filaments in chromosomal segregation and cellular division of Escherichia coli.

Expression of the cafA gene at 71 min on the E. coli chromosome map by use of a high copy number expression vector caused (1) overproduction of the 51 kDa CafA protein, (2) formation of chains of normal cells and shorter anucleate cells, and (3) formation of flexible, tough structures, which we call 'cytoplasmic axial filaments', running throughout the centre of the chained cells. In this article we shall describe the morphology, physiology and possible functions of the cytoplasmic axial filament structure. This structure could be a strong candidate for one of the procaryotic cytoskeletal/cytokinetic elements functioning in cellular extension and division, chromosomal segregation and other important mechanisms involved in the proliferation of procaryotic cells.

Amino Acid Sequence↗