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Biomedical subjects

S Ohara

Publications and source records attributed to S Ohara.

At least 181 records · Page 10Linked to original sources
PubMed1989

[Massive hemorrhage within an acoustic neurinoma. Case report].

A 39-year-old male experienced unilateral right hearing loss and tinnitus for 7 years and was hospitalized after he suddenly developed severe headache, vertigo, and right facial paralysis. Computed tomography (CT) showed a round, high-density are in the right cerebellopontine angle. Magnetic resonance (MR) imaging demonstrated a crescent-shaped region of high signal intensity, representing hemorrhage, in the superior aspect of the tumor, surrounded by edema. The right internal auditory canal was enlarged. Four-vessel angiography disclosed neither an aneurysm nor an arteriovenous malformation. A right suboccipital craniectomy revealed an encapsulated mass 3 cm in diameter in the right cerebellopontine angle. The tumor was totally removed. Histological examination revealed a typical neurinoma composed of Antoni type A and B cells. After undergoing anastomosis of the right hypoglossal and facial nerves, the patient was discharged in good condition. In this case MR imaging demonstrated intratumoral hemorrhage (which is rare in cases of acoustic neurinoma) and the surrounding tissue more clearly than did CT scanning.

Adult↗
PubMed1989

Effect of the proton pump inhibitor, NC-1300, on gastric mucus secretion in rats.

The effects of NC-1300 on gastric acid and mucus glycoprotein secretion were investigated in pylorus-ligated (4 h) rats. NC-1300 (30 mg/kg, intraduodenally) significantly inhibited gastric acid concentration more than 90%. The agent did not affect the total mucus glycoprotein output in the gastric juice, but caused by about 1.5 times denser mucus glycoprotein secretion than that in the control group. The amount of mucus glycoprotein in the mucous gel layer increased by about 1.4 times with this agent. Thus, NC-1300 not only inhibits acid secretion but also promotes mucus secretion, and this may explain its ability to protect the stomach against necrotizing agents.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1989

[Secondary degeneration of substantia nigra following massive basal ganglia infarction].

Two autopsied cases of massive unilateral cerebral infarction due to occlusion of the middle cerebral artery (MCA) were reported with special reference to presence of the secondary degeneration of the substantia nigra. Case 1 was a 70-year-old male who suddenly suffered from left hemiplegia 3 years and 2 months prior to death. CT scan showed massive infarction involving basal ganglia and fronto-parietal white matter on the right side. Some parkinsonian features such as oily face and rigidity of limbs were noted during the course. At autopsy, the proximal portion of rt MCA was found occluded and the right substantia nigra was found depigmented. Case 2 was a 71 year-old male who suddenly became hemiplegic 4 years prior to death. CT scan revealed a low density area in the corona radiata of the right cerebral hemisphere. On carotid antiography, complete obstruction of the horizontal portion of right MCA at its distal end was observed, which was confirmed at autopsy. Histologically, the right substant a nigra in case 1 showed marked neuronal loss with gliosis as well as presence of many extracellular melanin pigments. These changes were more prominent in its medial portion where chromatolytic neurons were occasionally seen. The adjacent fronto-pontine tract and pyramidal tract showed secondary degeneration. The left substantia nigra appeared normal. In case 2, the substantia nigra on both sides appeared normal. The whole right cerebral peduncle, on the other hand, showed diffuse myelin pallor.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[A case of focal nodular hyperplasia in the liver].

A case of focal nodular hyperplasia of the liver was reported, in which various diagnostic imaging modalities were performed. Hepatic colloid scan (SPECT) in this case shows typical focal accumulation in the lesion. Ultrasonic image shows a sharply demarcated hypoechoic lesion in the left lobe. But no significant informations of this tumor were obtained in the plain CT, CE-CT and angiography. Echo-guided biopsy was performed and focal cirrhotic finding in the lesion without liver cirrhosis was obtained.

Adult↗
PubMed1989

[A case of focal fatty liver difficult to distinguish from the liver metastasis of rectal cancer on CT].

The CT findings of focal fatty liver were previously described as follows, 1) nonspherical shape, 2) indistinct border, 3) absence of mass effect and 4) subsegmental appearance. We presented a case of focal fatty liver with spherical shape and distinct border, resembling the findings of liver tumor. In this case we could not rule out the liver metastasis from rectal cancer to the end. CT value and follow up examination are very useful to establish the proper diagnosis.

Adenocarcinoma↗
PubMed1989

Viability estimation of preserved dog kidneys based on the LDH activity in the preservation perfusate.

The lactate dehydrogenase (LDH) activity and LDH isozyme ratio in the perfusate were investigated in perfused dog kidneys, preserved from dogs subjected to warm ischemia of varying duration prior to kidney removal. The length of this warm ischemic time exerted a marked effect on the variations in both the LDH activity and isozyme ratio. Moreover, the variations in LDH activity and isozyme ratio during the preservation were found to correlate well. On this basis, the M-component activity of the LDH isozymes and the activity of the LDH4 and LDH5 isoenzymes are proposed to represent more sensitive parameters for evaluating the tissue hypoxic damage. Our data were also analyzed retrospectively, in relation to the ability of the perfused kidney to function on autotransplantation. It was found that the amount of LDH4 and LDH5 isoenzyme activity was of great value in determining the viability of the kidney. Thus, an analysis of the LDH activity in the wash solution can provide considerable and precise information about the kidney viability as a graft.

Animals↗
PubMed1988

Detection of UDP-N-acetylgalactosamine-oligosaccharide N-acetylgalactosaminyltransferase activity in rat stomach and human serum by high-performance liquid chromatography.

The enzymatic transfer of the sugar portion from UDP-N-acetylgalactosamine to pyridylamino (PA) lacto-N-fucopentaose I (Fuc alpha 1-2Gal beta 1-3GlcNAc beta 1-4Glc-PA) was detected by high-performance liquid chromatography. Separation of the fluorescent product from the fluorescence-labeled acceptor was achieved within 10 min by reversed-phase high-performance liquid chromatography. Rat stomach enzyme activity was detected in the microsomal fraction from antrum but not corpus. Ohara et al. (1986, Comp. Biochem. Physiol. 83B, 273-275) reported that the N-acetylgalactosamine content in antrum mucin was greater than that in corpus mucin and antrum mucin had strong blood group A activity. The prominent asymmetrical distribution of the enzyme detected here well supports these findings. The elution position of the fluorescent product was the same as that of the product formed by the action of type A human serum toward the acceptor. Its hydrolysis by alpha-N-acetylgalactosaminidase yielded the acceptor. It is thus evident that the detected enzyme is the same as that producing the blood group A structure.

Animals↗
PubMed1988

Alterations of oligodendrocytes and demyelination in the spinal cord of patients with mitochondrial encephalomyopathy.

The spinal cords of 2 autopsied patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) were examined. Histologically, the spinal cords showed a spongy state due to the presence of distended myelinated fibers with enlarged periaxonal spaces. Ultrastructurally, the affected fibers showed extensive microvacuolation of the inner myelin sheath with occasional vesicular changes. The presence of macrophages near the degenerated myelin was a frequent finding. The stripping of myelin lamellae by macrophage was observed, with frequent appearance of denuded axons. Furthermore, prominent morphological changes were observed in oligodendrocytes. These findings indicate that demyelination, probably secondary to the degeneration of oligodendrocytes, occurs in the spinal cord of MELAS.

Adolescent↗
PubMed1988

Two types of rat gastric mucus glycoprotein subunits.

Gastric mucus glycoproteins were extracted with 2% Triton X-100 from rat gastric corpus and antrum and purified by CsCl equilibrium centrifugation. Corpus mucus glycoproteins were degraded into what appeared to be two "subunits" (Mw 4.4 x 10(5) and 6 x 10(6)) by the reduction of disulfide bonds. Papain digestion of the latter produced glycopeptides with a molecular weight of approximately 4.4 x 10(5). This type of subunit had carbohydrate chains with about 9 sugars attached to every 2 amino acid residues. Papain digestion of the former type of subunit revealed no change in the elution profile on Bio-Gel A-15m. This type of subunit had carbohydrate chains with 17-19 sugars attached to every 3 amino acid residues. The subunit of antral mucus glycoproteins was essentially the same as the former type of corpus subunits in molecular weight (Mw 4.4 x 10(5)) and average oligosaccharide chain length. These results suggest that there are two distinct types of mucus glycoprotein subunits in rat stomach.

Animals↗
PubMed1988

Mucus glycoprotein and mucosal protection.

For assessing the participation of mucus glycoproteins in the cytoprotective process, mucus glycoprotein content in the rat gastric mucosa was measured after treatment with 70% ethanol with or without prostaglandin (PG) E derivatives or 20% ethanol pretreatment. Oral administration of two synthetic PGE derivatives did not cause any significant changes in mucus glycoprotein content. Seventy percent ethanol administration caused marked reduction in mucus glycoprotein content (about 50% of control) as well as severe gastric mucosal damage. Treatment with two PGE derivatives (10-100 micrograms/kg) prior to 70% ethanol administration markedly inhibited the gross mucosal lesion, whereas the glycoprotein content under these conditions was significantly less than that in the untreated control group (ranging from 67-88% of control). Pretreatment with 20% ethanol markedly inhibited the gross mucosal damage caused by 70% ethanol dosing but the inhibition in the reduction of mucus glycoprotein content was restricted to about 80% of the untreated controls. In summary, cytoprotection induced by PG was not accompanied by entire conservation of intramucosal mucus glycoprotein in the gastric mucosa.

Alprostadil↗