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Biomedical subjects

S Matsuda

Publications and source records attributed to S Matsuda.

910 records · Page 51Linked to original sources
PubMedDate not supplied

Effect of beraprost sodium (BPS), a prostacyclin analog, and dizocilpine (MK-801) on repeated ischemia-induced chronic cortical atrophy in gerbils.

We investigated the effect of beraprost sodium (BPS), a new prostacyclin analog, and dizocilpine (MK-801) on repeated ischemia-induced cerebral atrophy and chronic cortical neuronal loss in gerbils. The left common carotid artery of gerbils was repeatedly occluded (for 10, 7, 7, and 7 min) at intervals of 24 h. The thickness of the cerebral cortex of the ischemic hemisphere diminished with increasing time of reperfusion after an ischemic insult. The animals were given BPS (1-100 micrograms/kg, po) or MK-801 (3-300 micrograms/kg, sc) after the first ischemic insult, and then twice daily for 4 wk. Increases in the amount of neuronal loss and acidophilic neurons, and progressive atrophy were observed with increasing time of reperfusion in the cerebral cortex of the ischemic hemisphere. Cortical sections revealed no astrocytes positive for glial fibrillary acidic protein (GFAP), whereas the hippocampal CA1 area showed neuronal loss accompanied by GFAP-positive astrocytes. In control animals at 4 wk survival, the area ratio (area of ischemic cortex/area of opposite cortex) and the cortical neurons ratio (number of neurons in ischemic cortex/number of neurons in opposite cortex) were 89.8 +/- 3.0% and 74.6 +/- 3.4%, respectively. BPS was found to inhibit atrophy and chronic cortical neuronal loss in the ischemic hemisphere in a dose-dependent manner, whereas MK-801 showed no inhibitory effects at any dose tested. These results may suggest that the nature of neuronal degeneration differs between the cortical and hippocampal areas, that cortical neuronal degeneration might not involve glutamate pathways with NMDA receptors in this model, and that prostacyclin could play an essential role in prevention of ischemia-induced progressive neuronal loss.

Animals↗
PubMedDate not supplied

CT manifestations of a ruptured hepatic tumor after transcatheter arterial embolization.

There are few reports of the radiologic diagnosis of ruptured hepatic tumors. In a patient with right upper abdominal pain and impending shock, angiography demonstrated a hypervascular hepatic tumor, and CT imaged an extrahepatic mass suggestive of a hematoma. Following transcatheter arterial embolization with Lipiodol Ultrafluide and gelatin-sponge, multiple contiguous CT sections revealed numerous lipiodol droplets adjacent to a lipiodol-containing hepatic tumor, clearly outside the liver. These findings were indicative of a ruptured hepatic tumor. After embolization, the patient's condition improved and he was discharged.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Ocular activity of topically administered anandamide in the rabbit.

Marijuana and its psychoactive constituents, cannabinoids, reduce intraocular pressure (IOP) in humans and animals. Because anandamide, a recently discovered endogenous ligand of cannabinoid receptors, reportedly shows cannabimimetic pharmacological activity, we examined its effect on the eye. Varying amounts of anandamide, in 50 microL of light mineral oil, were topically applied to a rabbit eye and changes in IOP and ocular symptoms were monitored. Anandamide (50 micrograms to 1 mg) induced a significant decrease in IOP within 1 hour after administration; maximum reduction occurred at 2 hours; and there was a return to baseline by 7 hours following administration. A noticeable hyperemia of conjunctival blood vessels was also noted 2 hours after administration. Neither mineral oil alone or with palmitylethanolamide (an analogue of anandamide) caused a significant decrease in IOP or conjunctival hyperemia. This study indicates that anandamide does produce cannabimimetic effect in rabbit eyes.

Administration, Topical↗
PubMedDate not supplied

ALDH2 polymorphism and biological monitoring of toluene.

In this study, we evaluated the effects of the genetic polymorphism of ALDH2 (low Km aldehyde dehydrogenase) on toluene metabolism and determined biological exposure indices (BEIs) of the genotypes of ALDH2. The study subjects included 45 toluene workers and 122 nonexposed students. The genotype of ALDH2 was classified into the homozygous genotype of normal ALDH2 (NN), the homozygous genotype of an inactive one (DD), and the heterozygous genotype of normal and inactive ones (ND) by means of artificial-RFLP. The personal exposure levels to toluene were monitored, using diffusion type samplers and urinary hippuric acid (HA) and creatine concentrations were determined. The urinary HA levels of the three genotypes of ALDH2 of nonexposed students did not differ. In the toluene workers, positive correlations between the personal exposure to toluene and urinary HA levels were observed in the NN, ND, and DD groups. The urinary HA level of the DD group was significantly lower than that of the NN or ND group. Regression lines were used to estimate the BEIs of the NN, ND, and DD groups, which were approximately 2.9 g/g creatinine, 3.3 g/g creatinine, and 1.9 g/g creatinine, respectively.

Adult↗
PubMedDate not supplied

Yeast glucan in the cyst wall of Pneumocystis carinii.

Ultrastructurally, the cyst wall of Pneumocystis carinii consists of an electron-dense outer layer, an electron-lucent middle layer, and an innermost plasmalemma. This is similar in appearance to the cell wall of some yeasts, e.g. Saccharomyces cerevisiae, which consists of an outer dense layer of mannan, a middle lucent layer of beta-1,3-glucan (yeast glucan) and an innermost plasmalemma. The cyst wall of P. carinii, as well as the cell wall of S. cerevisiae, can be labeled by a variety of methods which stain polysaccharides, such as Gomori's methenamine silver (GMS) and by Aniline blue, a dye which selectively stains beta-1,3-glucan. The treatment of P. carinii cysts with Zymolyase, which the key enzyme is beta-1,3-glucan laminaripentaohydrolase, results in lysis of the outer 2 layers of the cyst wall and the loss of positive staining by both GMS and Aniline blue. The lysis of elements of the cyst wall of P. carinii is achieved under the same conditions and concentration at which Zymolyase lyses the outer 2 layers of the cell wall of viable cells of S. cerevisiae. These observations indicate that a major component of the cyst wall of P. carinii is beta-1,3-glucan.

Animals↗
PubMedDate not supplied

Corneal epithelial deficiency induced by the use of beta-blocker eye drops.

Two studies were conducted to check the effects of beta-blocker eye drops, 2% carteolol (Mikelan) and 0.5% timolol (Timoptol), on regeneration of corneal epithelium in rabbit eyes. For the short-term study, epithelial deficiency was artificially induced in the cornea of albino rabbits. One of the beta-blocker eye drops or 0.005% benzalkonium chloride was applied in the right eye and physiological saline solution was applied to the left eye four times a day, and wound healing rate was calculated. Two weeks later, images of the surface epithelium were analyzed by scanning electron microscopy and proliferative capacity was studied, using proliferating cell nuclear antigen as a marker. The long-term study was conducted similarly except that the eye drops were applied twice a day and epithelial deficiency was re-induced every two weeks. In the short-term study, epithelial wound healing rate was slowed in beta-blocker groups. Significant differences were detected between the Mikelan and Timoptol groups, and the benzalkonium and physiological saline groups. The beta-blocker groups had severe epithelial cell desquamation, as well as detachment. In the long-term study, the Mikelan group had significantly delayed wound healing at first induction, the benzalkonium group showed delay up to the third induction and the Timoptol group up to the fifth induction. These studies indicate that beta-blocker eye drops delay corneal epithelial wound healing and supported the concept that corneal epithelial deficiency occurs clinically after the long-term administration of beta-blocker eye drops.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Surgical management of intracavitary cardiac tumors. A review of fifteen patients and current status in Japan.

Fifteen patients with intracavitary cardiac tumors were operated on at the Kobe University Hospital between September 1977 and January 1984. Three of the patients were men and twelve were women. They ranged in age from 9 to 75 years. Their symptoms were chest pain, dyspnea, cough, palpitation and syncope. Definite diagnosis was confirmed by echo- and cineangiocardiography. There were 14 benign tumors consisting of 13 myxomas, one leiomyoma and one malignant myxosarcoma. The left atrium was the most common chamber involved (12 instances), followed by the right atrium (3). Surgery was performed in all cases under cardiopulmonary bypass with moderate hypothermia and cold crystalloid cardioplegia. Tumors were removed en bloc at the base with their attachment to the atrial septum or free wall in all cases. Three patients underwent concomitant mitral annuloplasty or mitral commissurotomy. Two cases with left atrial myxoma died postoperatively: one case associated with mitral annuloplasty died of congestive heart failure due to newly developed chordal rupture two months after surgery, and the other died of congestive heart failure 13 months after the first operation. Re-excision for recurrence of the myxosarcoma in the left atrium was performed in the latter case as a second surgical procedure. The remaining 13 cases with benign tumors are doing well and are without recurrence. From these favorable results, surgical intervention should be recommended prior to the occurrence of heart failure and severe complications such as coronary or peripheral embolism whenever cardiac tumors are detected by non-invasive echocardiography and cineangiocardiography.

Adolescent↗