PubMed Health⌕ Search

Biomedical subjects

K Urata

Publications and source records attributed to K Urata.

At least 37 records · Page 2Linked to original sources
PubMed1997

Effect of calcium antagonists on rat liver during extended cold preservation-reperfusion.

BACKGROUND: Nisoldipine, a calcium antagonist, has been reported to improve the quality of grafted rat livers. We thus assessed the protective effect of two calcium antagonists, nisoldipine and nickel, during extended cold ischemia-reperfusion. METHODS: Rat livers were isolated and perfused before or after 24 hr of cold ischemia in University of Wisconsin solution (4 degrees C) with or without nisoldipine or nickel. Sinusoidal endothelial cell and hepatocyte functions were measured by hyaluronic acid and taurocholate elimination, respectively. RESULTS: Similar alterations in hepatocyte and sinusoidal cell functions were found in all groups after cold ischemia with or without calcium antagonists. In a second set of experiments, liver transplantation was performed in two groups of rats with livers stored under identical conditions with or without nisoldipine. Seven of 12 animals (62.5%) in both groups survived for over 10 days after 24-hr preservation in University of Wisconsin solution. Survival rates were similar in both groups. CONCLUSIONS: Calcium antagonists do not appear to have a direct protective effect on sinusoidal endothelial cell and hepatocyte functions, nor on the overall liver preservation after extended cold preservation-reperfusion.

Adenosine↗
PubMed1996

Simultaneous observation of regional cerebral blood flow and event-related potential during performance of an auditory task.

Reduced amplitude of the P300 component has been reported consistently in patients with neurological and psychiatric disorders. It is unclear, however, how such patients' cognitive dysfunction is related to their P300 abnormality. Further basic knowledge regarding neural substrates for P300 generation is required for gaining an understanding of the pathological significance of the P300 amplitude reduction. To determine the brain structures involved in P300 generation, we observed the event-related potential and the regional cerebral blood flow (rCBF) in 10 normal subjects performing an oddball discrimination of pure tones. The rCBF value was assessed quantitatively with the aid of single photon emission computed tomography using technetium-99m hexamethylpropylene amine oxime. During the task performance, significant activation was observed in the posterior superior temporal and inferior parietal regions of the right hemisphere. In addition, positive correlation of the task-related increase in rCBF with the simultaneously recorded P300 amplitude was observed in the right but not the left posterior superior temporal region. These findings indicate that activation of the right non-verbal auditory area might modulate P300 generation during pure-tone discrimination.

Acoustic Stimulation↗
PubMed1996

Laparoscopic closure for perforation of the sigmoid colon by endoscopic linear stapler.

Immediate open surgery has been recommended for the management of perforation during colonoscopic examination. Laparoscopic closure for perforation of the sigmoid colon caused by diagnostic colonoscopy is described. The perforation site was identified in the antimesenteric border of the sigmoid colon by laparoscopic survey, and four ports were inserted in the lower abdomen. The margin of the perforation was lifted by two graspers, and the defect was completely closed using an endoscopic linear stapler. The patient recovered quickly without any associated complications. Postoperative barium enema showed no stenosis or leakage. This method is less invasive and allows earlier recovery of patients with colonic perforation.

Aged↗
PubMed1995

A new genus of marine budding phototrophic bacteria, Rhodobium gen. nov., which includes Rhodobium orientis sp. nov. and Rhodobium marinum comb. nov.

Strains of a previously undescribed species of purple nonsulfur phototrophic bacteria were isolated from coastal seawater in Japan. These new isolates were gram-negative, motile, budding rods that contained lamellar intracytoplasmic membranes and produced pink to red cultures. Cell extracts of photosynthetic cultures exhibited absorption maxima at 377, 468, 500, 530, 591, 802, and 870 nm, indicating that bacterio-chlorophyll a and carotenoids of the spirilloxanthin series were present. The new isolates were halophilic, facultatively aerobic photoheterotrophs that grew anaerobically in the light or aerobically in the dark. Maximum growth occurred in the presence of 4 to 5% NaCl. Anaerobic growth in the dark with nitrate as a terminal electron acceptor also occurred. Various organic compounds were used as photosynthetic electron donors and carbon sources. Sulfate was used as a sulfur source. Both menaquinone 10 and ubiquinone 10 were produced; these quinones were the major quinones. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain MB312T (T = type strain), a representative of the new phototrophs, was a member of a lineage that was distinct from members of the genus Rhodopseudomonas; Rhodopseudomonas marina was the closest relative. On the basis of the data described above, we propose the name Rhodobium orientis gen. nov., sp. nov. for the new isolates. We also propose that Rhodopseudomonas marina Imhoff 1983 should be transferred to the genus Rhodobium as Rhodobium marinum comb. nov.

Bacteria↗
PubMed1995

Calculation of child and adult standard liver volume for liver transplantation.

Despite refinements in surgical techniques for liver transplantation, liver size disparity remains one of the most common problems in pediatric patients. Optimal liver graft size remains unknown and the volume of diseased liver in the recipient is not indicative of the volume (standard liver volume [LV]) optimal for the recipient's metabolic demands. To establish a formula for calculating the standard LV in the pediatric and adult populations for liver transplantation, whole LVs were measured using computed tomography (CT) in 96 patients (65 pediatric and 31 adolescent or adult subjects) with normal liver whose disease conditions did not seem to affect body weight (BW) or LV. In the 96 subjects, the ratio of estimated LV to BW decreased gradually as age increased until approximately 16 years, when it started to level off. On the other hand, there seemed to be a directly proportional relationship between the estimated LV in vivo and body surface area (BSA) (r = .981; r2 = .962; P < .0001) in the subjects as a whole, and the formula, LV (mL) = 706.2 x BSA (m2) + 2.4, was established from the measured data by simple regression analysis. Another predicting equation, LV (mL) = 2.223 x BW (kg)0.426 x body height (BH) (cm)0.682, was produced by multiple regression analysis (r2 = .969; P < .0001). Considering its simplicity of use, we adopted the first formula for predicting standard LV in an individual patient.

Adolescent↗
PubMed1994

Modulation of coagulation and fibrinolysis in hepatic resection: a randomized prospective control study using antithrombin III concentrates.

A randomized prospective control trial for determining the efficacy of antithrombin III concentrates in hepatic resection was performed using 24 patients with hepatocellular carcinoma. Thirteen patients were given antithrombin III concentrates (1,500 IU) immediately before operation, during hepatectomy and immediately after operation. Coagulant and fibrinolytic profiles were determined by molecular markers such as thrombin-antithrombin III complex and plasmin-alpha 2plasmin inhibitor complex. During hepatic resection, both hypercoagulability and mainly primary hyperfibrinolysis occurred. Regarding the effectiveness of antithrombin III concentrates, in the antithrombin III treatment group, only a significant lower incidence of positive soluble fibrin monomer complex at postoperative days 1 and 5 was found among all the parameters studied. Therefore, no definite evidence of clinical usefulness of the perioperative administration of antithrombin III concentrates in hepatic resection was proved.

Aged↗
PubMed1994

Multiple hepatic hemangiomas with significant arterioportal venous shunting.

A patient with multiple hepatic hemangiomas and significant arterioportal shunting who was successfully treated by a left-hepatic lobectomy is presented herein. In hemangiomas with significant arterioportal venous shunting, it is essential to differentiate between hepatocellular carcinoma and hypervascular metastatic tumors because few typical findings of hemangioma can be recognized. Moreover, an increased hepatic arterial flow can increase the risk of spontaneous rupture as well as portal hypertension due to the increased inflow to the portal vein. Therefore, a definitive diagnosis should be made by liver biopsy when imaging alone is not sufficient to rule out malignancy. Furthermore, hepatic resection for hemangiomas with significant arterioportal venous shunting may be indicated due to the higher risk of rupture and the possibility of progressive portal hypertension.

Angiography↗
PubMed1994

Lipiodolization for unresectable hepatocellular carcinoma: an analysis of 205 patients using univariate and multivariate analysis.

Since 1982 we have developed and successfully performed lipiodolization on 205 patients with unresectable hepatocellular carcinoma. The 1-, 2-, 3-, 4-, and 5-year survival rates were 55.6%, 31.7%, 16.3%, 8.7%, and 2.9%, respectively, while the median survival was 413 days, and 20 patients survived longer than 3 years after the first lipiodolization. Our study demonstrated that the factors for a comparatively good prognosis were as follows: patient older than 50 years, nodular type hepatocellular carcinoma < 5 cm in diameter, negative tumor invasion of portal vein, < 10 intrahepatic metastases, serum alpha-fetoprotein level < 400 ng/ml, and Okuda stage I. Lipiodolization did not cure hepatocellular carcinoma. It did, however, in this study, achieve a prolongation of the patient's survival.

Adult↗
PubMed1994

Evaluation and interpretation of symptom structures in patients with schizophrenia.

Seventy Japanese DSM-III-R schizophrenic patients were assessed for 30 clinical symptoms using the Positive and Negative Syndrome Scale (PANSS) of Kay et al. Principal component analysis was applied to the full item set of this scale and disclosed 5 orthogonal independent symptom groups: negative, hostile/excited, thought-disordered, delusional/hallucinatory and depressive components. Our results provided further support of the contention that more than 2 (i.e., positive and negative) dimensions are required to account for structures of the schizophrenic symptoms.

Adolescent↗
PubMed1994

Clinical correlation between necrosis of hepatocellular carcinoma nodule and early recurrence after hepatic resection.

Here we report on the case of a 51-year-old man who presented with a high-grade fever six weeks prior to hepatic resection. The resected specimen of the liver showed a well encapsulated and completely necrotic mass and some intrahepatic metastatic disease. Widespread multinodular recurrence in the liver remnant and metastatic foci in the bones were detected approximately one year after surgery. This case suggests that transcatheter arterial embolization--which aims to bring about necrosis of the tumor--followed by hepatic resection might increase the risk of early recurrence of hepatocellular carcinoma, due to the fact that tumor necrosis can facilitate the release of cancer cells from the primary tumor.

Bone Neoplasms↗
PubMed1994

Influence of hepatectomy on cell infiltration in the resected liver parenchyma compared with the biopsy specimen--a preliminary study.

We undertook a preliminary investigation to determine whether or not preoperative hepatitis activity can be evaluated by the finding of cell infiltration into the parenchyma of the resected specimen. In 28 patients who underwent hepatic resection, liver biopsies were obtained just after the laparotomy in order to make a histological comparison with the resected liver specimen. Histological changes were observed in 11 out of 28 patients. However, these were limited to minimal changes of neutrophil infiltration in the portal and subserosal area with no derangement of chronic cell infiltration. In addition, the preoperative liver function and operative findings did not differ between patients with and those without histological changes. The activity of hepatitis was therefore seen not to be histologically influenced by the surgical procedure. Thus, an accurate evaluation of chronic inflammatory cell infiltration activity in the resected liver specimen is a reliable indicator in chronic liver disease patients.

Adult↗
PubMed1994

Isolated hepatic caudate lobectomy.

BACKGROUND: Isolated caudate lobectomy is a challenging surgical procedure for which safe and reliable techniques have yet to be developed. METHODS: Isolated caudate lobectomy was performed by initial inflow control of the caudate lobe, full mobilization of the liver from the inferior vena cava by dividing all short hepatic veins, and parenchymal division dorsal to the major hepatic veins with a clockwise rotation of the liver while the liver was selectively devascularized by Pringle's maneuver and occlusion of the confluence of the major hepatic veins flush with the inferior vena cava. RESULTS: Two patients with cirrhosis underwent this procedure successfully without intraoperative hemodynamic instability or postoperative liver dysfunction. CONCLUSIONS: This technique allows safe and truly selective excision of the caudate lobe without the need for occlusion of the inferior vena cava or venovenous bypass.

Carcinoma, Hepatocellular↗
PubMed1993

Effect of diabetes mellitus on hepatic resection.

We evaluated the effect of diabetes mellitus on mortality and morbidity after elective hepatic resections. Of 209 patients who underwent hepatic resections between April 1985 and July 1990, 49 (23.4%) were diabetic. Postoperative morbidity was more common among diabetics than among nondiabetics (75.5% vs 51.3%), mainly due to hepatic decompensation (55.1% vs 36.3%) and intraperitoneal sepsis (18.4% vs 6.3%). However, their incidence of hospital death (2% vs 2.5%), mean +/- SD postoperative hospital stay (36.1 +/- 20.2 days vs 29.4 +/- 28.2 days), and long-term survival were comparable with those of nondiabetics. Diabetics with and without complications were similar in preoperative or postoperative insulin requirement, duration of diabetes, and preoperative fasting glucose. Nevertheless, all eight patients with 24-hour urinary glucose excretion above 1 g developed complications. We conclude that diabetics are at a high risk of morbidity, but not of mortality after elective hepatic resection.

Adolescent↗
PubMed1993

A quantitative magnetic resonance imaging study of patients with schizophrenia.

Twenty patients with schizophrenia and ten normal control subjects underwent magnetic resonance imaging of the brain. The volumes of several brain structures were measured using a computer image analysing system. The schizophrenic patients had significantly smaller left parahippocampal volume and larger left temporal horn volume than the control subjects. A larger body of the right lateral ventricle could be estimated in the schizophrenics, but this difference was not significant. In the patient group a non-significant negative correlation was established between the presence of positive symptoms and the left temporal horn volume. There was no significant correlation between the temporal horn and temporal lobe or medial temporal structures. Our results indicate that the left medial temporal structure or left temporal lobe may be involved in schizophrenia and that temporal horn enlargement does not simply represent volume loss of the surrounding tissue.

Adult↗
PubMed1993

SPECT analysis of regional cerebral blood flow changes in patients with schizophrenia during the Wisconsin Card Sorting Test.

Single photon emission computed tomography (SPECT) images were obtained in 10 right-handed neuroleptic-treated schizophrenic patients and 10 healthy volunteers using Tc-99m-hexamethyl-propylenamine oxime (Tc99m-HMPAO) during performance of the Wisconsin Card Sorting Test (WCST) and at rest. None of the patients showed severe impairment on the WCST. The patient group showed a statistically insignificant trend to incur more unique errors. In both the patient and control groups, the left lateral prefrontal blood flow significantly increased during the WCST, as compared to during resting conditions. Only during the WCST, the patient group showed a significant regional cerebral blood flow (rCBF) decline in the left medial prefrontal cortex, as well as in the right side under both the test and resting conditions. This left medial prefrontal rCBF during the WCST correlated positively with the number of unique errors, although this correlation was statistically insignificant. The right fronto-parietal rCBF was significantly increased in the patient group under both the test and resting conditions. Moreover, in the left hippocampal region, the patient group showed a significant rCBF increase under resting conditions.

Adult↗