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S Ohara

Publications and source records attributed to S Ohara.

At least 235 records · Page 13Linked to original sources
PubMed1986

[Effects of FO-1561 on postischemic cerebral functional and metabolic recovery in experimental cerebral ischemia].

Effects of S-adenosyl-L-methionine sulfate tosylate (FO-1561) on postischemic cerebral functional and metabolic recovery in experimental cerebral ischemia were investigated. Severe bilateral forebrain ischemia in rats was induced by four-vessel occlusion with reducing the mean arterial pressure to 100-110 mmHg. After forebrain ischemia had been maintained for 30 minutes, recirculation was started by removal of the arterial clamps of bilateral common carotid arteries and by increasing systemic arterial pressure to the preischemic level. The EEG was continuously recorded from gold-coated screws inserted bilaterally in the parietal bones with the tips in extradural position, against a reference inserted prefrontal bone. Analysis of power spectrum of EEG activity was done by Berg Fourier Analyser. The brains were frozen in situ with liquid nitrogen before, during and after ischemia and then chiselled out during irrigation with liquid nitrogen. Concentrations of ATP in brain tissue were determined with high performance liquid chromatography. FO-1561, 100 mg/kg, was given intravenously, immediately after recirculation. After recirculation there was a tendency that EEG power spectrum in FO-1561-treated animals contained higher percentage of beta wave compared to that in control animals, while delta wave was lesser in FO-1561-treated animals. At 90 minutes following recirculation, ATP level in control animals was 2.17 +/- 0.05 mumol/g (mean +/- SE) and 2.42 +/- 0.03 mumol/g (mean +/- SE) in FO-1561-treated animals. Thus, recovery of ATP level was significantly better in FO-1561-treated animals than in control animals (p less than 0.01).

Adenosine Triphosphate↗
PubMed1986

Ultrastructural alterations of perineurial cells in the early stage of Wallerian degeneration.

Ultrastructural changes of the perineurium in the distal segment of the mouse phrenic nerve after crush were studied at various intervals of up to 56 days. In the control, the perineurium of the phrenic nerves was composed of multilayered perineurial cells joined together by tight junctions forming concentric laminae surrounding the endoneurium which mainly contained myelinated fibers with a relatively small amount of unmyelinated fibers. In the experiment, perineurial cells showed prominent morphological changes from day 3 to day 6 with the presence of proteinaceous exudate between the cellular laminae of the perineurium. Some of the perineurial cells appeared hypertrophic and often showed mitotic figures. Newly formed gaps between the perineurial cells forming the same lamina as well as between those of adjacent laminae were frequently observed. Intracellular microcavities in the perineurial cells associated with increased pinocytotic vesicles were also observed. In addition, debris-free macrophages were occasionally seen in the perineurium. At this stage, axonal degeneration, myelin breakdown and interstitial proteinaceous exudate, which were already noticed on day 2, were evident in the endoneurium, demonstrating the early stage of Wallerian degeneration. From day 7 on, however, mitotic figures of perineurial cells were not encountered. Perineurial cells of inner laminae contained lipid droplets which increased in number with time. Our observations strongly suggest that perineurial cells play an important role in the early stage of Wallerian degeneration of the peripheral nerve.

Animals↗
PubMed1985

On the occurrence of the fenestrated vessels in Wallerian degeneration of the peripheral nerve.

Ultrastructural studies were made on the distal segments of the mouse phrenic nerve after crush injury. In the control, endoneurium contained only unfenestrated capillaries. In the experiment, from day 2 to day 6, endoneurial capillaries occasionally showed fenestrations with the attenuation of its cytoplasm. At this stage, axonal degeneration and myelin breakdown became evident showing early stage of Wallerian degeneration. In addition, detachment of the neighboring endothelial cells concomitant with the invasion of macrophage was also observed. These findings were previously unobserved changes of the endoneurial endothelium in Wallerian degeneration. The significance of the early occurrence of fenestrae was discussed briefly.

Animals↗
PubMed1985

Effects of ketamine on the dynorphin levels and the ethylketocyclazocine (EKC) receptor binding in discrete regions of rat brains.

Intraperitoneal (ip) injection of ketamine increased the concentration of dynorphin in the cortex of rat brain, while decreased it in the septal area. The affinity of ethylketocyclazocine (EKC) receptor binding was decreased in the cortex, but increased in the septal area after pretreating the rats with ketamine. This suggests that the dynorphin neuronal system is stimulated in the cortex and suppressed in the septal area by ketamine. In other 5 brain areas, ketamine had no effect on neither dynorphin concentration nor EKC receptor binding. As dynorphin was reported to produce seizure and spike discharge in the cortex while suppressed the hippocampal EEG of rat brain, it is likely that the dynorphin neuronal system may play at least a part in ketamine induced electrophysiological changes in the brain.

Animals↗
PubMed1985

Effects of fasting on mucus glycoprotein biosynthesis in rat stomach.

Biosynthetic activity of gastrin mucus glycoprotein in rats after fasting for 24 and 72 hr was studied by the organ culture technique. Fasting produced a slight reduction in gastric mucus glycoprotein biosynthesis in the corpus and antrum (about 70-90% of fed rats). Sulfation of gastric mucus glycoprotein was restrained in the corpus (18% in control for 72 hr).

Animals↗
PubMed1985

Characterization of sulfated glycoconjugates in human gastric mucosa.

Radiolabeled glycoconjugates were prepared by incorporation of [35S]sulfate and [3H]glucosamine into the gastric mucosa of human gastric resection specimens, using organ culture techniques. Specimens which incorporated higher amounts of [35S]sulfate into high molecular glycoconjugates (Fr-1) were designated as group I. The average specific activity in Fr-1 of group I was 30 times that of group II, but the glucosamine uptake remained about the same in all cases. All specimens in group I were positive to intestinal metaplasia in their adjacent mucosal area. The sulfated glycoproteins in Fr-1 of group I were found to incorporate 80% of the 35S and the remaining 20% by sulfated glycosaminoglycans. But the glycoconjugates constituting all the Fr-1 of group II were identified as glycoproteins and incorporating 35S only to a small extent were identified as sulfated glycoproteins. The susceptibility of the glycoproteins from group I mucosa to pronase digestion was different from that of group II. The glycoproteins synthesized in group I mucosa were as sulfated glycoproteins as well as nonsulfated glycoproteins and glycosaminoglycans, while the group II glycoproteins consisted primarily of nonsulfated glycoproteins.

Adult↗
PubMed1985

New trial of endoscopic treatment for gastric submucosal tumors.

Recently conservative treatment of gastric submucosal tumors is increasing in spite of the absence of definite criteria for histological diagnosis. We have developed a new method of endoscopical treatment of gastric submucosal tumors that have submucosographically intraluminal Pattern I or II, or partly intramural Pattern III. For such tumors with a maximum diameter less than 5 cm, Ist step: partial resection is carried out with the use of high-frequency electric currents, IInd step: for the residual tumor tissue, in vivo tissue solidification is undertaken by local injection of absolute ethanol to induce necrotic exfoliation of the tumor tissue and to prevent of hemorrhage.

Adult↗
PubMed1985

Diagnosis of the depth of cancer invasion by submucosography.

A new method was developed to diagnose the depth of cancer invasion using submucosography combined with special charcoal suspension containing mitomycin C, and applied to 8 cases of gastric cancer. Correct diagnosis of the depth of the cancer invasion was obtained in 7 of the 8 cases. As some cases of early gastric cancer can be treated endoscopically, it is important to know the condition of the invasion before any treatment is performed.

Aged↗
PubMed1985

A simple quantitative bradykinesia test in MPTP-treated mice.

A neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which produces pathological changes similar to human idiopathic Parkinson's disease in animals, was injected in mice for biochemical and pharmacological studies. The dopamine concentration showed a marked decrease (-75%) in the striatum 1-2 weeks after the injection of MPTP (30 mg/kg i.p. twice a day for 5 days; a total dose, 300 mg/kg) but no changes or only slight decreases in other brain regions. The norepinephrine concentration also decreased to half the preadministration level in the striatum. These changes closely resembled those observed in the brain of parkinsonian patients. An examination for evaluating bradykinesia of MPTP-treated mice (pole test) devised by the author revealed that bradykinesia was alleviated dose-dependently by injection of L-DOPA. These results suggested that MPTP-treated mice are a useful experimental model for the study of parkinsonism, and that the pole test using these animals is of value in the screening of anti-parkinsonian agents.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1985

[Percutaneous nephrostomy].

Sixty three cases (male 32, female 31) of supravesical obstruction were treated with ultrasonically guided subcutaneous nephrostomy at our hospitals from October 1980 to October 1984. Their age ranges from 2 months to 84 years old, and median age was 52 years old. The major causes of ureteral obstruction were extended pelvic malignancies, 45 cases (71%) (gynecological 18, urological 16, gastrocolorectal 7 and others 4), and benign disease 18 cases (29%). Objectives of nephrostomy were classified in 4 categories (drainage, manipulation, irrigation and evaluation), and results of nephrostomy were discussed for each category. No major complications were observed. Only prolonged macrohematuria (over 48 hours) and fever (over 38 degrees C) were observed in 5 cases respectively. Success rate of nephrostomy placement was 97.5% of all cases. With ultrasonography and angiographic technique, percutaneous nephrostomy is an easy, safe and reliable method.

Adolescent↗
PubMed1985

Effects of bencyclane on concussion following head injury in mice.

Bencyclane showed a dose-dependent anti-concussive effect with a duration of at least 60 minutes in an experimental model of concussion induced by head injury. This long-lasting effect cannot be explained only by the changes in the serum level of the agent or the increase in brain circulation due to its vasodilative action, both of which are of much shorter durations. Our findings suggest that bencyclane causes alterations in brain metabolism, which is partly responsible for reduction in the duration of the experimental concussion.

Animals↗