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Biomedical subjects

Y Maeda

Publications and source records attributed to Y Maeda.

At least 973 records · Page 54Linked to original sources
PubMed1984

Effect of selective inhibitor of thromboxane A2 synthetase on cerebral vasospasm after early surgery.

The authors report the results of inhibition of thromboxane A2 synthetase in 49 consecutive patients with subarachnoid hemorrhage (SAH). These unselected Grade I to IV patients all had a ruptured aneurysm of the anterior circle of Willis, and were operated on within 72 hours after SAH. Twenty-seven patients were treated postoperatively by an intravenous infusion of sodium (E)-3- [4-(3-pyridylmethyl)-phenyl] -2- propenoate (OKY-1581), a selective inhibitor of thromboxane A2 synthetase, at 5 micrograms/kg/min for 10 to 14 days, and the remaining 22 patients did not receive this drug. Both groups of patients had similar age distribution and preoperative neurological conditions. A suggestive but statistically insignificant improvement was found in postoperative angiographic vasospasm, ischemic symptoms, and overall outcome in the group receiving OKY-1581. The incidence of low-density areas on the postoperative computerized tomography scans was significantly decreased in patients treated with OKY-1581 infusion.

Acrylates↗
PubMed1984

Effects of tamoxifen on estrogen-induced enhancement or inhibition of tumor growth in mouse Leydig cell tumor lines.

In order to avoid the complex dual effects of estrogen and antiestrogen, the attempt was made to establish the tumor lines in which estrogens show either stimulatory or inhibitory property in terms of the tumor growth. The administration of estrogen to host mice bearing one of the mouse Leydig cell tumor lines, called T 124958-R, resulted in marked enhancement of the tumor growth even at pharmacological levels of estrogen. On the other hand, estrogenization of host mice almost completely inhibited the growth of the other tumor line (T 22137) without detectable stimulatory effects. The physiocochemical properties of the cytosol estrogen receptor in both sublines were found to be similar in relation to the affinity toward ligands, steroid specificity, sedimentation profile, and the dissociation rate kinetics. Using these tumor lines, the action mechanism of tamoxifen on the tumor growth was examined. Daily administration of this compound (30 micrograms/mouse) led to enhanced tumor growth in T 124958-R, while the growth of T 22137 was inhibited by the same procedure. In the combination experiments, tamoxifen was found to be unable to antagonize estrogen-induced enhancement or inhibition of the growth in these tumors. In addition, both tumors contained similar levels of the antiestrogen binding sites. These results suggest that tamoxifen modulated the tumor growth through its estrogenic potency.

Animals↗
PubMed1984

[An arachnoid cyst in the left lateral ventricle].

Generally arachnoid cysts are congenital in origin and found over the cerebral convexity, in the major fissures, and in the folded portions of the brain wherever the arachnoid membrane extends. Including other central nervous system (CNS) cysts, the location of these cysts has implications as to their origin, for examples, intracerebral cysts generally are ependymal cysts, while extracerebral cysts are mostly arachnoid cysts. An 8-month-old boy was admitted to our department because of enlarged head and developmental retardation. Computerized tomographic scan (CT) revealed remarkable hydrocephalus and a relatively high-dense, round lesion between the lateral ventricles. During surgery the cyst was found to arise from the left ventricular floor. Histologically the cyst wall was arachnoid membrane.

Arachnoid↗
PubMed1983

An association of subtotal cerebellar agenesis with organoid nevus--a possible new variety of neurocutaneous syndrome.

A quite unique patient aged 13, characterized by a combination of organoid nevus on the left scalp and subtotal cerebellar agenesis accompanied by hypoplasia of the pons and midbrain, was reported. Cardinal clinical features consisted of nonprogressive cerebellar manifestations including intention tremor and ataxia, speech and visual disturbance and mental retardation. An electronystagmogram demonstrated periodic alternating nystagmus. A clinical diagnosis of cerebellar agenesis in this case was made through the demonstration of characteristic features in metrizamide CT and midline sagittal tomography of metrizamide cisternography of the posterior fossa. An extensive review of the literature revealed three papers dealing with organoid nevus associated with various neurological abnormalities, but no single case with a similar combination of cutaneous organoid nevus and cerebellar agenesis had been reported.

Adolescent↗
PubMed1983

Clinical studies on diverticular disease of the colon.

In 12,505 patients who received barium enemas during the past 14 days, 979 cases (7.8%) of diverticular disease of the colon (DDC) were found. The incidence of DDC increased with age; 2.2% of the patients were below age 29 and 14.3% were over 70 years old. The sex distribution was 584 males and 395 females. 76.1% had diverticula in the right-side colon, 12.9% in the left-side colon, and 11.0% in both sides. All patients below age 29 had the right-side colon type, while 44% of those aged 70 or more did. On the other hand, the left-side colon type and both-sides colon type were found only in patients over 30 years old, and constituted a majority in those of 70 years old or more. The main symptoms and signs were: disturbances in bowel habits 50.7%, abdominal pain 48.1%, abdominal distension and/or discomfort 41.5%, occult blood 25.2% and melena 5.8%. Therefore, DDC is clinically becoming an important disease in recent years in Japan as well as in Western countries.

Adolescent↗
PubMed1983

Effects of prostacyclin and indomethacin on experimental delayed cerebral vasospasm.

Isolated canine basilar artery contracted by prostaglandin E2, hemoglobin, or serum was relaxed in a dose-dependent manner by the addition of 10(-8)M to 10(-6)M prostacyclin (PGI2), and was scarcely relaxed by 10(-9)M PGI2. In other studies, intravenous administration of PGI2 (25 or 75 ng/kg/min), indomethacin (4 mg/kg), or indomethacin (4 mg/kg) plus PGI2 (25 ng/kg/min) failed to reverse angiographic delayed vasospasm produced in vivo in the canine basilar artery by an intracisternal injection of blood. In addition, no significant increase occurred in mean values of regional cerebral blood flow (rCBF) with any treatments, and mean rCBF difference in dogs treated by PGI2 infusion at 25 ng/kg/min was 2.5 +/- 1.2 ml/100 gm/min and only significantly increased (p less than 0.01). Mean arterial blood pressure was significantly reduced by PGI2 infusion at 25 (p less than 0.05) or 75 ng/kg/min (p less than 0.005).

Animals↗