Biomedical subjects

K Miyata

Publications and source records attributed to K Miyata.

459 records · Page 26Linked to original sources

PubMedDate not supplied

Accessory nerve damages and impaired shoulder movements after neck dissections.

PURPOSE: After neck dissection, where the accessory nerve is often excised patients usually complain of impaired shoulder movements. The accessory nerve forms a plexus with branches of the cervical nerves C2, C3, and C4. In the present study, the accessory nerve was examined during neck dissections to clarify the incidence of motor fibers in joining branches, and the function of the motor fibers was evaluated postoperatively in relation to shoulder movements. MATERIALS AND METHODS: Presence of cervical contributions to the accessory nerve were examined in 20 neck sides in 15 patients. Postoperative function of the shoulder movements was evaluated by manual muscle testing (MMT) and electromyography (EMG). RESULTS: Motor fibers in cervical contributions were noted on four sides (20%) by stimulation of joining branches. When the accessory nerve was excised, scapular elevation was rarely impaired even if there were no motor fibers in the cervical contributions. Excision of the accessory nerve caused poor scapular adduction and impaired scapular depression and adduction in most cases even if motor fibers in the cervical contributions existed. CONCLUSION: Postoperative impairment of scapular movements was not attributed to the presence or absence of motor fibers in joining branches. Results obtained with electromyography did not represent the practical function of the muscle.

Accessory Nerve↗

PubMedDate not supplied

A method for measurement of muscarinic receptor-mediated responses in dissociated single colon longitudinal smooth muscle cells.

We previously reported a simple method of acutely preparing dissociated smooth muscle cells from urinary bladder tissue, but the feasibility of this method has not been well ascertained. In the present study, we assessed whether this method is applicable for measuring muscarinic receptor function in intestinal smooth muscle cells. Single smooth muscle cells were prepared from the longitudinal muscle tissue of guinea pig colon by the enzymatic dissociation with papain and hyaluronidase, followed by collagenase digestion. Muscarinic responses in the isolated smooth muscle cells were measured by intracellular Ca(2+) mobilization and extracellular acidification through Fura-2 fluorometry and Cytosensor microphysiometry, respectively. A single, viable population of colon longitudinal smooth muscle cells (approximately 6 x 10(6) cells/animal) was obtained. In these cells, carbachol (muscarinic agonist) induced Ca(2+) mobilization and extracellular acidification over the concentration range similar to that previously reported to produce contraction of the intact colon muscle strips. Atropine (nonselective muscarinic antagonist) and 4-diphenylacetoxy-N-methylpiperidine (4-DAMP, M(3)-selective antagonist) inhibited the Ca(2+) mobilization with potencies approximately 3 log units greater than that for methoctramine (M(2)-selective antagonist). For extracellular acidification, the potency differences between these antagonists was approximately 2 log units. In addition, the carbachol-induced extracellular acidification was inhibited by 5-[N-ethyl-N-isopropyl]-amiloride, a selective inhibitor of the Na(+)/H(+) exchanger. These findings indicate that in isolated colonic smooth muscle cells, M(3) receptors are predominantly involved in Ca(2+) mobilization, while a mixed population of M(2) and M(3) receptors seems to contribute to extracellular acidification. Our results further suggest the role of the Na(+)/H(+) exchanger in muscarinic-mediated extracellular acidification. Consequently, our method produces viable isolated colonic smooth muscle cells that display physiologically appropriate responses to muscarinic receptor activation, and the method may be applicable for several types of nonvascular smooth muscle tissues.

Amiloride↗

PubMedDate not supplied

Neonatal mature teratoma of the sphenoidal sinus: a case report.

Teratoma in the head and neck region is very rare. We treated a child with a mature congenital teratoma that arose from the right sphenoidal sinus. He is doing well after early surgical treatment with endoscopic endonasal resection of the tumor.

Endoscopy↗

PubMedDate not supplied

Mucosal dysplasia in the bile duct after choledochoduodenostomy: a case report.

A 60-year-old woman who had undergone cholecystectomy, choledocholithotomy and choledochoduodenostomy 21 years previously for cholecystolithiasis and choledocholithiasis, presented with nausea and vomiting. With a preoperative diagnosis of recurrent common bile duct stones, the extrahepatic bile duct was excised and choledochojejunostomy was performed. Histologic examination of the resected specimen disclosed chronic cholangitis, papillary epithelial hyperplasia, and mild dysplasia. Choledochoduodenostomy predisposes to reflux of duodenal contents, resulting in chronic mechanical and chemical irritation likely to induce histopathologic alterations in the bile duct mucosa. Since bile duct dysplasia induced by chronic inflammation may be a precursor of cancer, indication for choledochoduodenostomy should be specific and limited, and careful long-term follow-up is mandatory.

Bile Ducts↗

PubMedDate not supplied

Percutaneous transhepatic balloon dilation for papillary stenosis.

In this study, a case of primary common bile duct stone due to papillary stenosis is reported. The patient was a 68-year-old man with complaints of epigastric pain and fever who had undergone gastrectomy at age 55 and cholecystectomy with choledocholithotomy at age 62. Laboratory data revealed elevation of the transaminases acid biliary enzymes. Both abdominal ultrasonography and CT scan revealed dilatation of the common bile duct with stones. Since endoscopic retrograde cholangiopancreatography could not visualize the bile duct, percutaneous transhepatic biliary drainage was carried out. After lithotripsy by percutaneous transhepatic cholangioscopy a diagnosis of papillary stenosis was made following percutaneous transhepatic manometry of the sphincter of Oddi, and balloon dilatation through the PTBD fistula was successfully performed. In this case report, emphasis is placed on the diagnosis and treatment of papillary stenosis.

Aged↗

PubMedDate not supplied

Species difference in the 5-hydroxytryptamine3 receptor associated with the von Bezold-Jarisch reflex.

Species differences in the 5-hydroxytryptamine (5-HT)3 receptor among anesthetized rats, mice, rabbits, ferrets, dogs and guinea-pigs were examined in the transient bradycardia induced by i.v. injection of 5-HT (the von Bezold-Jarisch reflex). We also investigated the mechanism of the 5-HT-induced bradycardia in these species. 5-Hydroxytryptamine and the selective 5-HT3 receptor agonists, 2-methyl-5-HT and m-chlorophenylbiguanide, dosedependently decreased heart rate in all species. In anesthetized rats, mice, ferrets and guinea-pigs, 2-methyl-5-HT and m-chlorophenylbiguanide behaved as full agonists against the 5-HT3 receptor, whereas their agonistic action in rabbits was partial. On the basis of ED50 values, there was no marked species difference in the potency of 5-HT3 receptor agonists. In contrast, the blocking activities of the 5-HT3 receptor antagonists, YM060, YM114 (KAE-393), granisetron and ondansetron, were markedly weaker in anesthetized guinea-pigs than in the other species. With regard to the mechanism of the 5-HT-induced bradycardia, YM060, atropine or vagotomy completely inhibited the 5-HT-induced bradycardia in anesthetized rats and mice. In guinea-pigs, in contrast, higher doses of YM060 and atropine or vagotomy inhibited this reflex by approximately 80%. Although the YM060-resistant part of the 5-HT-induced bradycardia in guinea-pigs was affected by neither 5-HT2 receptor antagonists nor 5-HT4 receptor antagonists, it was completely abolished by methysergide, a 5-HT1-like and 5-HT2 receptor antagonist. These results suggest that there is a species difference in the 5-HT3 receptor between guinea-pigs and other species in the von Bezold-Jarisch reflex system. They also suggest that the 5-HT-induced bradycardia in anesthetized rats and mice is evoked by acetylcholine released through activation of 5-HT3 receptors on the vagus nerve, while that in guinea-pigs is, at least in part, mediated through 5-HT1-like receptors in addition to 5-HT3 receptors.

Animals↗

PubMedDate not supplied

Weight of resected liver is positively correlated with serum hHGF level.

BACKGROUND/AIMS: Human hepatocyte growth factor (hHGF) is involved in the control of liver regeneration. MATERIAL AND METHODS: We measured serum hHGF levels before and after partial hepatectomy in 43 patients and recorded the weight of the resected liver. RESULTS: Serum hHGF levels increased soon after operation and decreased thereafter. In the noncirrhotic group, the maximum hHGF concentration and the area under the curve of hHGF seven days postoperatively correlated with the weight of the resected liver. CONCLUSION: The amount of injured liver tissue can be approximated by the serum hHGF levels. This calculation can be useful in evaluating cases of hepatectomy, general hepatic injury, liver transplantation, and other types of hepatic damage.

Adult↗

PubMedDate not supplied

Levels of human hepatocyte growth factor (hHGF) in peritoneal fluid after partial hepatectomy.

BACKGROUND/AIMS: Human hepatocyte growth factor (hHGF), now known to be identical with scatter factor and tumor cytotoxic factor, is thought to be involved in the regeneration of the liver in humans. MATERIAL AND METHODS: We measured the levels of immunoreactive hHGF levels in peritoneal fluid before and after partial hepatectomy in 37 patients, 10 with and 27 without cirrhosis. The presence of hHGF was confirmed in human peritoneal fluid with rat hepatocytes in primary culture and Western blot. RESULTS: Levels of hHGF increased significantly in peritoneal fluid after surgery, with its total concentration being correlated with the weight of resected liver 168 hours postoperatively. CONCLUSION: Findings suggest that the hHGF levels in peritoneal fluid may indicate the extent of hepatic damage following partial hepatectomy and other liver diseases.

Adult↗

PubMedDate not supplied

Sensitivity and specificity of several immunochemical tests for colorectal cancer.

BACKGROUND/AIM: The purpose of this study was to evaluate the diagnostic accuracy of new different immunochemical fecal occult blood tests for colorectal cancer, including Iatro Hemcheck, Immudia-Hem Sp, LA Hemochaser, Monohaem and OC-Hemodia. METHODOLOGY: Ninety-six patients with colorectal cancer and the same number of healthy controls served as subjects for the study. In this study, each subject received a set of five immunochemical tests over three consecutive days; and sensitivities and specificity of these tests were evaluated. RESULTS: Mean sensitivity and specificity in a set of five immunochemical tests were 91.0% and 95.2%, respectively. Sensitivities and specificity of five different immunochemical tests were calculated as 92.7% and 92.7% for Iatro-Hemcheck, 90.6% and 96.9% for Immudia-Hem Sp, 88.5% and 96.9% for LA Hemochaser, 91.7% and 95.8% for Monohaem, and 91.7% and 93.8% for OC-Hemodia, respectively, showing no significant difference in sensitivity and specificity among five tests. CONCLUSIONS: These results suggest that immunochemical tests for fecal occult blood tests has high diagnostic validity for colorectal cancer. In addition, there is no significant difference in the degree of accuracy among the several types of immunochemical tests.

Colorectal Neoplasms↗