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Biomedical subjects

S Ohara

Publications and source records attributed to S Ohara.

At least 127 records · Page 7Linked to original sources

[An operative case of the dumbbell type retromediastinal schwannoma].

Neurogenic tumors of the mediastinum with an intraspinal component connected by a narrowed segment in the intervertebral one are generally described as dumbbell or hour-glass tumors, which need cautious and precise diagnoses and remedies, compared with other neurological tumors. A 62-year-old male was admitted to our hospital for abnormal tumor shadow in the chest X-ray film. We diagnosed this case as dumbbell type neurogenic tumor by MRI and CT. An operation was performed by modified Grillo's method: One-stage operation. With patient in prone position, L-shaped skin incision was made. Through total laminectomy of T-5 and T-6 and resection of the 6th rib, paravertebral portion of the tumor was removed, and thoracotomy in the same position under the same view enabled us to remove the residual tumor. Histopathological diagnosis was schwannoma. After the operation, no neurological complications were detected.

Humans↗

[Primary and experimental study of a new treatment for hepatolithiasis by injection of resin in the intrahepatic bile duct].

In the treatment of hepatolithiasis, it is sometimes difficult to remove the stones completely and residual stones are closely related to the prognosis. In cases with residual stones, cholangitis frequently recurs and sometimes it causes fatal hepatic failure. We postulated that filling the hepatic bile duct with resin may be useful for the prevention of the progress of this disease. This experiment is the preliminary study on this new treatment for hepatolithiasis. After the injection of Neoprene resin into the left intrahepatic bile duct of a mongrel dog, histological changes of the liver and biochemical changes in peripheral blood were serially analyzed. After six months, the Neoprene plug remained in place. In the lobe treated with Neoprene, volume and weight decreased, and fibrosis around the bile duct and interlobular connective tissue increased, while, the number of hepatocytes was not changed. There was neither abscess nor biloma in the liver. Blood analysis revealed only a transitional increase of GOT, GPT and ALP. No complication was caused by this treatment. From this result, we conclude that this new method may be useful for the treatment of hepatolithiasis.

Animals↗

Biosynthesis of two distinct types of mucin in HM3 human colon cancer cells.

Mucins, high-M(r) glycoproteins with a large amount of O-glycosidically linked carbohydrate, protect the colonic epithelial surface and are altered in ulcerative colitis and colon cancer. At least two mucin genes, MUC2 and MUC3, are expressed at high levels in the human intestine. As an experimental model for studying the biosynthesis of human intestinal mucins, we used HM3 colon cancer cells. When mature mucins labelled with [3H]glucosamine or [3H]threonine were analysed by gel filtration, it was found that secreted mucins (M(r) > 10(8) were larger than soluble cellular mucins (M(r) approx. 5 x 10(6)). Only secreted mucin was sensitive to reduction. Both MUC2 and MUC3 proteins, identified by labelling with [3H]threonine or [35S]cysteine and immunoprecipitation with antibodies to synthetic mucin peptides, were already of large size (M(r) > 180,000) by the earliest labelling time (5 min). The MUC3 precursor was completely degraded by trypsin, but the MUC2 precursor had a trypsin-resistant fragment of M(r) approx. 240,000 containing threonine and cysteine. The trypsin-resistant MUC2 fragment contained N-linked carbohydrate, as indicated by a decrease in size as a result of peptidyl N-glycosidase digestion or tunicamycin treatment of HM3 cells. These results show that HM3 colon cancer cells produce at least two distinct human intestinal mucins. They also indicate that the mechanisms of biosynthesis of intestinal mucins differ from those of other mucin-like glycoproteins that have been studied.

Amino Acid Sequence↗

Transganglionic neuropeptide Y response to sciatic nerve injury in young and aged rats.

Gracile neuroaxonal dystrophy (NAD) is a hallmark of the aging human and rodent sensory nervous systems which may represent an abnormal transganglionic response to peripheral axonal injury. To examine the structural plasticity of central dorsal root ganglia (DRG)-derived axons in the gracile nucleus, we evaluated the response of the lumbar DRG and their central projections to sciatic nerve injury in young and old rats. In uninjured rats neither the DRG nor its central projections contained histochemical immunoreactivity for neuropeptide Y (NPY). However, within 1 week of sciatic nerve crush or transection injury, NPY immunoreactivity appeared in the lumbar DRG and its central projections, reaching an apparent maximum in number and intensity of processes at 28 days. Neuropeptide Y immunoreactivity was more intense and sustained in response to transection compared to crush injury, results supported by NPY radioimmunoassay. Neuropeptide Y-immunoreactive processes in the gracile nuclei of axotomized young animals consisted of delicate axons or slightly enlarged profiles that may represent regenerative elements. Lumbar dorsal rhizotomy performed simultaneously with sciatic nerve transection prevented the transganglionic NPY response. Dystrophic axons in the gracile nucleus of non-lesioned aged animals were not NPY-immunoreactive; however, after sciatic nerve transection, NPY immunoreactivity developed in both delicate axons and markedly swollen dystrophic elements, a finding confirmed by ultrastructural immunolocalization. These results establish that despite the presence of NAD in DRG projections to aged gracile nuclei these elements remain capable of a plastic NPY response to peripheral nerve injury.

Aging↗

Effects of Z-300, a new histamine H2-receptor antagonist, on mucin biosynthesis in rat gastric mucosa.

We examined the effects of Z-300 (N-[3-[3- (piperidinomethyl)phenoxy]propyl]-2-(2-hydroxy-ethyl-1-thio)acetam ido.2- (4-hydroxy benzoyl)benzoate), a newly-synthesized selective histamine H2-receptor antagonist, on mucin in rat gastric mucosa. Deep corpus mucin content increased significantly to 127% of the control after the administration of 30 mg/kg of Z-300, whereas that in the antral mucosa did not increase. The addition of Z-300 significantly increased [3H]-labeled mucin in the corpus region. In the antrum, biosynthetic activity showed no significant change by 10(-8)-10(-5) M of Z-300. These results suggest that Z-300 not only inhibits acid secretion but may also promote gastric mucus metabolism in the corpus region.

Acetamides↗

Emerging symptoms of growing skull fracture after secondary trauma in an adult--case report.

A 20-year-old female presented with dysphasia and slight hemiparesis following a head trauma, who had a non-treated growing skull fracture which had remained asymptomatic for about 18 years, despite an encephalocele in the left parietal region. Neuroimaging demonstrated secondary brain damage and herniated brain resulting in gliosis. Electroencephalography revealed epileptic discharge in the affected region. Dural repair and cranioplasty resolved her neurological deficits. Early corrective surgery should be performed for growing skull fracture to prevent secondary brain damage.

Adult↗

[Diagnosis of gallbladder cancer by imaging techniques: problems, limitations and their explanations, especially with ss invasive cancer].

The preoperative diagnosis of less than ss depth gallbladder cancer is difficult. Its preoperative diagnosis rate was low (27.5%), and even lower with the presence of concomitant gallstone. In the latter case, the diagnosis rate was particularly low when the stones diameter was greater than 1 cm. Gallstones are frequently associated with macromorphologically invasive type of gallbladder cancer and this may be the reason for the lower diagnostic rate. We compared preoperative diagnosis rate of ultrasonography (US), computed tomography (CT) and drip infusion cholecystography (DIC) for each invasion depth. In US, the preoperative diagnosis rate for m depth invasion was 6/16 (37.5%), pm depth was 1/13 (7.7%), and ss depth was 14/41 (34.1%). In CT, its rate for m depth was 3/11 (27.3%), pm depth was 1/10 (10.0%), and ss depth was 11/37 (29.7%). In DIC, its rate for m depth was 3/11 (27.3%), pm depth was 1/10 (10.0%), and ss was depth 1/23 (4.3%). None of the currently used imaging techniques were very accurate in diagnosing gallbladder cancer. Thus, during preoperative work up, if one discovers a gallbladder full of stones, stones of greater than 1 cm in diameter, thickened gallbladder wall, or a non visualized gallbladder with DIC, gallbladder cancer must be highly suspected.

Cholecystography↗

Effect on gastric mucus of the proton pump inhibitor leminoprazole and its cytoprotective action against ethanol-induced gastric injury in rats.

The effect of leminoprazole ((+-)-2-[[2-(isobutyl-methylamino)benzyl]sulfinyl]-1H-benzimidazol e, NC-1300-O-3, CAS 104340-86-5), a new compound being developed as an inhibitor of the gastric mucosal proton pump (H+,K(+)-ATPase), on gastric mucus secretion was studied by a biochemical method measuring the gastric mucin content in rats. Oral administration of leminoprazole (30 mg/kg) strongly inhibited the hemorrhagic lesions induced by 60% ethanol containing 0.15 mol/l HCl (acid-ethanol) administered 1 h later. Leminoprazole significantly inhibited the acid-ethanol-induced reduction of the mucin content in the surface mucosa including the mucus gel layer, but no significant effect could be obtained on the reduction of mucin present in the deep layer of the corpus and antral mucosa. Leminoprazole given to rats not treated with acid ethanol accelerated the secretion of deep mucosal mucus and increased significantly the content of soluble mucus which was recovered from the gastric luminal contents to about 200% of control, but failed to produce any significant change in the mucus content present in the surface mucosal and the mucus gel layers. The effect of leminoprazole on gastric mucus secretion might contribute to healing the peptic ulcer diseases and may be involved in the cytoprotective mechanism of this drug.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Comparative study on rat enteromucins.

1. Mucus glycoproteins (mucins) were extracted from the duodenum, small intestine (proximal and distal parts) and colon. 2. Enteromucin subunits were larger than 2 x 10(6). 3. The glycopeptides of enteromucins were essentially the same in size of the subunit. 4. The carbohydrate portion of enteromucins consisted of N-acetylgalactosamine, N-acetylglucosamine, galactose, fucose and sialic acid and the ratios of these sugars differed according to the region. 5. Average oligosaccharide length was about 8, 8, 8 and 14 sugars in the duodenum, proximal small intestine, distal small intestine and colon, respectively. 6. The proportion of threonine to serine in small intestinal mucins differed from duodenal and colonic mucins. Duodenal and colonic mucins were richer in threonine than small intestinal mucins. 7. Proximal and distal small intestinal mucins showed the same features. 8. A comparison of rat enteromucins to gastromucins indicated enteromucins to have large subunits and glycopeptides. The threonine and sialic acid content of enteromucins was higher and fucose content less compared to gastromucins.

Acetylgalactosamine↗

Regional differences in pig gastric mucins.

1. Mucus glycoproteins (mucins) were extracted from cardiac, fundic and pyloric regions of pig stomach. 2. The cardiac and pyloric regions were richer with mucins than the fundic region. 3. Threonine and proline content decreased in the order of cardiac, fundic and pyloric mucin. That of serine increased in the order of cardiac, fundic and pyloric mucins. 4. The carbohydrate of gastric mucins consisted of N-acetylgalactosamine, N-acetylglucosamine, galactose and fucose. The ratios of carbohydrate composition among cardiac, fundic and pyloric mucins differed. 5. Average oligosaccharide length was about 14-15, 12-13 and nine sugars in cardiac, fundic and pyloric mucins, respectively. 6. Disulfide bond reduction of mucins with dithiothreitol led to the production of a larger (M(r) about 8.8 x 10(7)) and a smaller subunit (M(r) about 1.2 x 10(6)). Their ratio differed for each of the three regions. The proportion of the larger subunit decreased in the order of cardiac, fundic and pyloric mucins, as 100, 61.4 and 44.8%, respectively.

Acetylgalactosamine↗

Cancer-associated retinopathy with retinal phlebitis.

A 50-year-old man with cancer-associated retinopathy was investigated using light and electron microscopy, immunofluorescence studies, and western blotting. He had visual disturbance, ring-like scotoma, and night blindness bilaterally. There were narrowed retinal arterioles and dilated retinal venules. Oral corticosteroid therapy had positive effects. Immunostaining using the patient's serum revealed a positive reaction in the ganglion cell layer of normal retina. Western blotting showed that the patient's serum antibody reacted with normal retinal proteins of 24 and 48 kDa. Multiple metastases were evident at autopsy.

Antigens, Neoplasm↗

Effect of lansoprazole on intragastric pH. Comparison between morning and evening dosing.

Lansoprazole is a newly developed proton pump inhibitor. The purpose of this study was to determine whether morning or evening dosage gave better control of 24-hr intragastric pH. In this study, we examined the antisecretory effect of lansoprazole by repeated intragastric pH monitoring on four occasions in eight normal subjects and compared median 24-hr pH values and pH threshold time of pH greater than or equal to 4 between morning and evening dosing, following the administration of lansoprazole 30 mg once daily in either the morning or evening for seven days. Intragastric pH was monitored before and after seven days of treatment. Both morning and evening dosing caused a rise in the intragastric pH. Median pH for 24 hr was 4.3 and 1.6 with and without lansoprazole morning dosing and 4.6 and 2.1 for evening dosing, respectively. The pH threshold curve shifted to the right with lansoprazole treatment in either case. However, no differences were found between morning and evening dosing in terms of median 24-hr pH values or pH threshold time of pH greater than or equal to 4. These results indicate that lansoprazole can be given once daily in either the morning or evening because of its potent and long-lasting antisecretory activity.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Effects of tetragastrin on mucus glycoprotein in rat gastric mucosal protection.

The effects of tetragastrin on mucus glycoprotein (mucin) metabolism and mucosal protection in rat gastric mucosa were investigated. Rats were administered with various doses of tetragastrin (12, 120, or 400 micrograms/kg body weight; s.c.), followed by 50% ethanol-induced gastric injury. Tetragastrin caused a significant increase in mucin content in the corpus mucosa and prevented 50% ethanol-induced gastric mucosal damage in a dose-dependent manner. For assessment of the effects of tetragastrin on the metabolism of gastric mucin in detail, changes in mucin distribution in the three different layers of rat gastric mucosa were examined one hour after single administration of tetragastrin. A significant increase in the mucin content was noted in the mucus gel and surface mucosal layer. Mucin content in the deep mucosa corresponding mainly to the mucus neck cell mucin underwent virtually no change by this treatment. An increase in mucin in the mucus gel and surface mucosa would thus appear due to the administration of tetragastrin and may possibly be related to the protective action of the gastric mucosa against injury. The data demonstrate a possibility that gastrin may have potential for enhancing gastric mucosal protection associated with mucus secretion and/or mucus synthesis on the surface mucosa of rat gastric mucosa.

Animals↗

Ossifying fibroma of the thoracolumbar spine: a case report and review of the literature.

A 43-year-old woman with ossifying fibroma of the thoracolumbar vertebrae was presented with a 6-month history of progressive radiculomyelopathy. The symptoms were successfully treated by laminectomy and partial resection of the lesion. This is the first reported case of ossifying fibroma involving the thoracolumbar spine. The clinical significance and management of this rare lesion are discussed with a review of the literature.

Adult↗