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Biomedical subjects

A Okada

Publications and source records attributed to A Okada.

At least 289 records · Page 16Linked to original sources
PubMed1993

Bile duct atresia following extended right hepatectomy because of a tumor.

A 19 month old male infant with a mesenchymal hamartoma of the liver underwent an extended right hepatectomy. Serum bilirubin gradually rose until 3 months after the surgery, and obstructive jaundice and acholic stools were manifested at 6 months. Percutaneous transhepatic cholangio-drainage was performed. Cholangiography showed dilation of the intrahepatic bile duct of the residual lateral segment and complete obstruction of the extrahepatic bile duct. A second operation for reconstruction of the biliary tract was performed 10 months after the first surgery. No aspect of an extrahepatic biliary tract was found. Histological inspection of a surgical specimen of remnant tissue revealed only cicatricial connective tissue without any biliary structures. The clinical course has been uneventful for 18 months since the second surgery. The cause of bile duct atresia in this case is strongly suggested to be an ischemic change due to devascularization of the extrahepatic biliary tract following hepatic resection because of a tumor. To prevent this kind of complication, hepatico-enterostomy should be performed close to the cut surface of the liver.

Biliary Atresia↗
PubMed1993

A case of biliary stricture caused by cavernous transformation of the portal vein.

A case is reported of extrahepatic obstruction of the portal vein with the unusual complication of obstructive jaundice that resulted from compression of the common bile duct caused by cavernous transformation of the varicose network. It is surgically impossible to repair choledochal stenosis resulting from enlarged varices in the vicinity of the common bile duct. In this case, internal drainage from the biliary duct to the duodenum using a silastic tube and a reservoir implanted in the subcutaneous space successfully eliminated the jaundice.

Adolescent↗
PubMed1993

A case of urethral prolapse in a young girl.

Urethral prolapse is rarely reported in the pediatric literature. We report a 4 year old female with urethral prolapse and discuss the etiology and the treatments in children documented in the literature.

Child, Preschool↗
PubMed1993

Triazolam and nitrazepam use in elderly outpatients.

OBJECTIVE: To determine adverse reactions and effects on sleep among three groups of patients: those taking triazolam, those taking nitrazepam, and a control group. DESIGN: Telephone interviews. PATIENTS: Forty-seven patients taking triazolam, 36 taking nitrazepam, and 40 control patients. All study participants were outpatients over 60 years of age. RESULTS: The rate of awakening in the middle of sleep was not significantly different among patients taking triazolam (61.7 percent) and those taking nitrazepam (69.4 percent). Incidence of nocturia, the primary reason for awakening, was not significantly different between triazolam- (36.2 percent) and nitrazepam-taking patients (41.7 percent). The rate of having difficulty falling back to sleep was significantly different among triazolam (62.1 percent) and nitrazepam (8 percent), and triazolam and control (11.1 percent) groups (p < 0.01). No difference was evident, however, between nitrazepam and control groups. CONCLUSIONS: Patients taking nitrazepam have less difficulty returning to sleep compared with those who take triazolam. Thus, for elderly patients who awaken because of nocturia, nitrazepam may be more appropriate therapy.

Aged↗
PubMed1993

Increased aspartate and glutamate levels in both gastric and colon cancer tissues.

The concentrations of free amino acid and protein-bound amino acid in gastric and colon cancers and also in normal tissues were measured and compared in order to investigate the differences in amino acid metabolism between these cancers. The examined materials were 20 specimens of gastric cancer, with 20 specimens of normal gastric full-thickness layers and 11 specimens of normal gastric mucosal layers, as well as 16 specimens of colon cancer, with 12 specimens of normal full-thickness layers and 16 specimens of normal colon mucosal layers. The amino acid pattern in gastric cancer was more similar to that in the gastric full-thickness layer than the gastric mucosal layer. On the other hand, the pattern in colon cancer was more similar to the colon mucosal layer than the full-thickness layer of normal colon tissue. Comparison between gastric and colon cancers showed that almost all of the protein-bound amino acid levels in gastric cancer were significantly higher than in colon cancer, while, conversely, all of the free amino acid levels except for aspartate, glutamate and glutamine were significantly lower in gastric cancer than in colon cancer. Both in the stomach and colon, the aspartate and glutamate levels in cancer tissues were significantly higher than in normal full-thickness or mucosal layers.

Aspartic Acid↗
PubMed1993

A newborn case of extrarenal malignant rhabdoid tumor.

Malignant rhabdoid tumor is initially differentiated from renal tumors and characterized by extremely rapid growth. We report a newborn case of extrarenal malignant rhabdoid tumor and review the literature.

Diagnosis, Differential↗
PubMed1992

Membrane-bound conformation of mastoparan-X, a G-protein-activating peptide.

Mastoparan-X, a tetradecapeptide from wasp venom, has been proposed to cause secretion from various kinds of cells by the direct activation of GTP-binding regulatory proteins (G proteins) that couple to phospholipase C. The mechanism of the activation has been shown to be very similar to that of G-protein-coupled receptors in vitro, and the interaction with membranes seems to be very important for the activation of G proteins that are membrane-bound [Higashijima, T., Uzu, S., Nakajima, T., & Ross, E. M. (1988) J. Biol. Chem. 263, 6491-6494]. We report here the precise vesicle-bound conformation of mastoparan-X in the presence of perdeuterated phospholipid vesicles, determined by two-dimensional 1H-NMR analyses of transferred nuclear Overhauser effects, combined with distance geometry and molecular dynamics calculations. Of 14 amino acid residues, the C-terminal 12 residues take an alpha-helical conformation upon binding to the phospholipid bilayer. The overall structure of the alpha-helix is amphiphilic, with three lysine side chains located on one side and with hydrophobic side chains on the other side. This conformation of mastoparan-X was maintained both in the gel and in the liquid-crystalline phases of the membranes. The conformation described herein will provide a useful basis for understanding conformation-activity relationships of mastoparan analogs as activators of G proteins. These studies will help to design novel potent analogs for the regulation of G proteins and to analyze receptor-G-protein interactions.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1992

Zinc-deficient diet impairs adaptive changes in the remaining intestine after massive small bowel resection in the rat.

An investigation was conducted on the influence of the presence of zinc in an elemental diet on the mucosa of residual intestine after massive small bowel resection. A total of 34 male Sprague-Dawley rats were divided into five groups: control animals (n = 10) were killed after overnight fasting; a second group (n = 14) underwent massive small bowel resection preserving 10 cm of terminal ileum, and the third group (n = 10) underwent sham operation. Animals in the second and third groups were fed either a commercially available elemental diet or a zinc-deficient diet for 2 weeks; they were then killed. In animals receiving the zinc-deficient diet, a significant decrease (P < 0.05) was noted in plasma zinc and total protein, and in mucosal wet weight (duodenum), thickness (duodenum and ileum), and protein (duodenum) and DNA (duodenum) content. Mucosal sucrase and maltase specific activities in the duodenum and ileum fell but diamine oxidase levels did not. These results suggest that zinc plays an important role in intestinal adaptation in the rat, and indicate that this trace element is essential for intestinal mucosal preservation in this animal.

Adaptation, Physiological↗
PubMed1992

Massive small bowel resection in neonates--is weaning from parenteral nutrition the final goal?

Eight surviving cases from an original 15 pediatric patients who underwent massive small bowel resection during their neonatal period were reviewed for a period of 2-19 years to assess long-term prognosis. the primary diseases were congenital intestinal atresia in 6 cases and midgut volvulus in 2. The length of the residual small intestine ranged from 27-75 cm and the ileocaecal valve had been resected in 3 cases. All cases were able to be weaned from parenteral nutrition and at present, 6 of the children can tolerate normal meals but 2 are still receiving enteral nutrition, in the form of a low residue diet at home. Near normal somatic growth was achieved in the most recent 5 cases who received intensive nutritional treatment in the immediate postoperative period, whereas 3 who did not receive nutritional management exhibited growth retardation. The D-Xylose absorption test revealed gradual improvement and finally normal absorption in all except one case with the shortest remaining intestine (27 cm). However, the fat absorption test revealed abnormal absorption in cases with a residual intestine of less than 45 cm. Late metabolic complications such as renal calculi, cholelithiasis and pathologic fractures were encountered in 3 cases.

Child↗
PubMed1992

Effects of whole body microwave exposure on the rat brain contents of biogenic amines.

The effects of whole body microwave exposure on the central nervous system (CNS) of the rat were investigated. Rats weighing from 250 to 320 g were exposed for 1 h to whole body microwave with a frequency of 2450 MHz at power densities of 5 and 10 mW.cm-2 at an ambient temperature of 21-23 degrees C. The rectal temperatures of the rats were measured just before and after microwave exposure and mono-amines and their metabolites in various discrete brain regions were determined after microwave exposure. Microwave exposure at power densities of 5 and 10 mW.cm-2 increased the mean rectal temperature by 2.3 degrees C and 3.4 degrees C, respectively. The noradrenaline content in the hypothalamus was significantly reduced after microwave exposure at a power density of 10 mW.cm-2. There were no differences in the dopamine (DA) content of any region of the brain between microwave exposed rats and control rats. The dihydroxyphenyl acetic acid (DOPAC) content, the main metabolite of DA, was significantly increased in the pons plus medulla oblongata only at a power density of 10 mW.cm-2. The DA turnover rates, the DOPAC:DA ratio, in the striatum and cerebral cortex were significantly increased only at a power density of 10 mW.cm-2. The serotonin (5-hydroxytryptamine, 5-HT) content in all regions of the brain of microwave exposed rats was not different from that of the control rats. The 5-hydroxyindoleacetic acid (5-HIAA) content in the cerebral cortex of microwave exposed rats was significantly increased at power densities of 5 and 10 mW.cm-2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Anterior sagittal anorectoplasty for rectovestibular and anovestibular fistula.

Rectovestibular (or anovestibular) fistula is the most common form of anorectal anomaly in female infants. In the surgical repair of these malformations, anal transplantation has been in widespread conventional use. Based on the idea of posterior sagittal anorectoplasty, we devised a new approach, anterior sagittal anorectoplasty, in which, in the lithotomy position, the anterior portion of sphincter muscles are cut through a median perineal skin incision and then the rectum is pulled through the center of these muscles to make its opening at the normal position. The operation has been performed in 12 patients with satisfactory results.

Anal Canal↗
PubMed1992

Injection of bleomycin as a primary therapy of cystic lymphangioma.

Forty-five patients (19 boys and 26 girls) with lymphangioma have been treated at Osaka University Hospital during the 10-year period from January 1978 to December 1987. Twenty-nine underwent initial bleomycin (BLM) therapy. These patients' lesions consisted of large cystic masses that were demonstrated by echography or computed tomography scans. BLM was administered as a solution of 1 mg/mL in saline, after aspiration of the cyst contents using a puncture needle. The total dose ranged from 3 mg to 32 mg (average, 10 mg) and was administered between 1 and 16 times. Of the 29 cases treated with BLM, 25 cases (86%) showed significant reduction of the mass and 16 (55%) showed complete disappearance. Recurrence occurred in 3 patients. One responded to further injection of BLM, and the other 2 required surgical resection. Thirteen patients required surgical resection; however, in those cases, the previous injection of BLM was found to minimize the extent of surgical resection required. There were no serious side effects with BLM injection. Injection of BLM as an initial treatment of cystic lymphangioma was found to be very useful. It can reduce the size of the mass and even result in complete disappearance; consequently, it can minimize the frequency and extent of surgical intervention.

Bleomycin↗
PubMed1992

Intrapancreatic duodenal duplication associated with pancreatic pseudocysts.

A rare case of intrapancreatic duodenal duplication causing pancreatitis is reported. At 2 years of age, the patient presented with a recurrent pancreatic pseudocyst. Intraoperative pancreatogram showed the presence of cystic duodenal duplication in the aberrant lobe of the pancreas communication with the pancreatic duct. Since the resection of the duplication, she has been free from recurrence of pancreatitis. In this case, intraoperative pancreatography was of great value.

Duodenum↗
PubMed1992

Activation of cerebral dopaminergic systems by noise and whole-body vibration.

To clarify the involvement of the central nervous system in responses of organisms to noise and whole-body vibration, the activity of dopamine (DA) neuron systems was estimated by examining DA turnover rates in various discrete regions of the brains of rats exposed to noise (broad band, 102 dB) or whole-body vibration (20 Hz, 4G) for 90 min. Plasma corticosterone level (COR) was determined simultaneously as an index of stress-induced autonomic-nervous and endocrine functions. Noise and whole-body vibration increased both COR and DA turnover rates (shown by an increase of homovanillic acid (HVA) and/or HVA/DA ratio) in the frontal cortex (FC) and the nucleus accumbens (NAc). Only noise increased the DA turnover rate in the amygdala (AMY). Furthermore, strong positive correlations of the HVA/DA ratios in the FC and the NAc with COR were observed in rats exposed to noise or vibration. These results suggest that the responses of organisms to noise and whole-body vibration may be critically mediated by cerebral DA systems, in particular by the mesocortical DA system, indicating that change of DA in the AMY can be considered a specific response to noise.

Animals↗
PubMed1992

Experimental studies on the pathogenesis of the gastric mucosal lesions induced by whole-body vibration.

In order to determine the pathogenesis of gastric mucosal lesions induced by whole-body vibration (WBV), the effects of WBV (3.0 G, 10 Hz, 90 min) on gastric mucosal blood flow (GMBF), plasma corticosterone (COR) and catecholamines (CA), and gastric ulcer formation were investigated in relation to the effects of forced water-immersion stress (FWI) upon the same parameters. While WBV increased GMBF during the exposure, FWI decreased it both during and after the stress. No difference in the severity of ulcer formation between the WBV and the FWI groups was seen. Both WBV and FWI increased plasma COR and CA, although the degree of the increase in COR that accompanied WBV was less than that associated with FWI. Truncal vagotomy attenuated the reduction of GMBF and the extent of ulcer formation that occurred with FWI, but promoted a reduction of GMBF with WBV. These findings indicate that ulceration induced by WBV may be caused primarily by its direct and specific mechanical actions and not by indirect, central nervous system effects known to be important in the pathogenesis of ulcerations produced by mental stress.

Animals↗