Search PubMed⌕ Search

Biomedical subjects

Y Maki

Publications and source records attributed to Y Maki.

At least 163 records · Page 9Linked to original sources
PubMed1986

Novel reactions of 5-bromouracil derivatives with active methylene compounds.

5-Bromouracil derivatives (1) reacted with carbanions at room temperature to give 6-substituted uracils (6), 2,4-diazabicyclo[4,1,0] heptanes (8) and 2,4-diazabicyclo[4,3,0]nonane derivative (9), which depend largely upon the structure of the active methylene compounds employed for the generation of carbanions.

Alkanes↗
PubMed1986

[Spinal epidural arteriovenous malformation fed by bilateral internal iliac arteries].

A rare case of a spinal epidural AVM fed by bilateral internal iliac arteries is reported. The patient was a 50 years old female with symptoms of slowly progressive paraparesis and sensory disturbance below L-2 associated with sphincter disorders. Myelography disclosed a serpiginous filling defect at the lumbar region. Selective internal iliac arteriograms disclosed an AVM fed by bilateral lateral sacral arteries. The nidus was excised totally, then a gradual improvement of those symptoms followed. Reviewing the literature, only 9 cases of spinal AVM of this type have been reported. In the majority of these cases, symptoms progressed slowly from the lower sacral level up to a level close to the end of the drainer. These symptoms were considered to be caused by steal phenomenon as well as by venous congestion due to arterialized intradural draining veins.

Arteriovenous Malformations↗
PubMed1986

[Cerebral venous thrombosis associated with the use of oral contraceptives].

The entity of cerebrovascular diseases associated with the use of oral contraceptives is well known but quite rare in Japan in contrast to Western countries. We recently encountered a 38 years old female with cerebral venous thrombosis considered to be caused by oral contraception. This patient took oral contraceptives for 17 days following therapeutic abortion, and was transferred to our hospital because of disturbed consciousness. CT scans disclosed a right temporo-occipital subcortical hemorrhagic infarction and bilateral thalamic infarction. Cerebral angiograms showed non-filling of cortical veins in the same area. The internal cerebral vein, vein of Galen and right transverse sinus were not visualized either. The hematoma and necrotic tissue were removed to avoid farther neurological deterioration. The brain was swollen and hyperemic, and thrombosed cortical veins were clearly recognized at operation. Twelve cases, including ours, of cerebrovascular diseases associated with oral contraception were reported up to now in Japan, and only 3 of them were diagnosed objectively as venous or sinus thrombosis. The average age of these 12 cases was 34 years old and many of them experienced abortion or therapeutic abortion. There was no relationship between the dose of estrogen and the onset of cerebrovascular diseases. We believe that the onset of this pathological state is based on gynecological hypercoagulable state, and the oral contraception may play a role of a trigger. Oral contraception should be contraindicated in patients with gynecological hypercoagulable state, hypertension and/or smoking habit.

Adult↗
PubMed1985

Gastric mucosal protection by spizofurone.

The protective effect of spizofurone (AG-629) on the rat gastric mucosa was studied in the presence of various stimuli. Spizofurone given orally markedly inhibited gastric lesions induced by ethanol (ED50 = 6.5 mg/kg). Spizofurone inhibited ethanol-induced gastric lesions even when administered intraperitoneally (i.p.), but the onset of action after oral administration was shorter. Spizofurone given orally or i.p. in a dose range of 25-200 mg/kg inhibited indomethacin-induced gastric antral ulcers in re-fed rats. Furthermore, spizofurone potentiated the inhibitory effect of prostaglandin E2 on indomethacin-induced gastric antral ulcers. Spizofurone given i.p. prevented a decrease in potential difference and the formation of gastric lesions induced by intragastric instillation of 30 mM aspirin in 0.1 N HCl. Spizofurone given i.p. inhibited the increase in net fluxes of H+ and Na+ caused by intragastric instillation of 15% ethanol in 0.1 N HCl. These findings indicate that spizofurone, like prostaglandin E2, exerts gastric mucosal protection and even potentiates the anti-ulcer effect of prostaglandin E2. The gastric mucosal protection by spizofurone is ascribed in part to preservation of the mucosal barrier.

Animals↗
PubMed1985

Spizofurone (AG-629) increases gastric mucosal blood flow in dogs: a possible mechanism of its anti-ulcer effect.

The effect of spizofurone (AG-629), a new anti-ulcer agent, on gastric mucosal blood flow was investigated in anesthetized dogs and the effects were compared with those of prostaglandin E2. Intravenous administration of spizofurone in doses of 15 and 30 mg/kg caused a dose-related increase in gastric mucosal blood flow. Spizofurone (1-10 mg/ml) given intragastrically for 15 min produced a sustained increase in gastric mucosal blood flow in a concentration-dependent manner; with 3 mg/ml there was about a 50% increase in gastric mucosal blood flow at the peak and a 2 h duration of action. The mode of action of spizofurone was similar to that of prostaglandin E2. The reduction in the gastric mucosal blood flow as induced by indomethacin was markedly improved by spizofurone. The topical action of spizofurone was confirmed in an in situ experiment using a stomach flap fixed to a lucite chamber. These results indicate that spizofurone increases gastric mucosal blood flow after systemic and topical administration, and this increase in gastric mucosal blood flow would account for the anti-ulcer effects of this drug.

Aminopyrine↗
PubMed1985

Avian retrovirus S13: properties of the genome and of the transformation-specific protein.

The avian retrovirus S13 codes for an env-linked transformation-specific glycoprotein with a molecular weight of 155,000 (gp155). Treatment of gp155 with endoglycosidase H or growth of S13-infected cells in the presence of tunicamycin reduces the molecular weight of gp155 to about 140K, but these gp155-related molecules may still contain sugar residues. The gp155 protein is not incorporated into virions; it is phosphorylated, but in immunoprecipitates does not show protein kinase activity. The genome of S13 is an 8.5-kilobase (kb) RNA; the helper virus genome is 7.5 kb in size. The putative onc sequences of S13 do not hybridize to DNA probes representing src, erb A, erb B, myc, myb, fps, fms, H-ras, B-lym, abl, rel, and ets.

Alpharetrovirus↗
PubMed1985

Intracerebellar hemorrhage due to cerebellar hemangioblastoma.

A rare case of a bleeding from a cerebellar hemangioblastoma is described. The tumor was diagnosed preoperatively with a computed tomography scan and a vertebral angiogram. The characteristic computed tomography scan findings and probable mechanism of bleeding are discussed.

Cerebellar Diseases↗
PubMed1985

Delayed intracerebral hemorrhage after ventriculoperitoneal shunt.

A serious intracerebral hemorrhage occurred as a result of a measurement for grip power performed on the 7th postoperative day of a ventriculoperitoneal shunt. This type of delayed intracerebral hemorrhage after the placement of a ventriculoperitoneal shunt has not been described in the literature. The increased intracranial venous pressure produced by Valsalva's effect induced this complication, which is also considered to be the same mechanism as traumatic delayed intracerebral hemorrhage.

Adolescent↗
PubMed1985

Studies on antianaphylactic agents. 7. Synthesis of antiallergic 5-oxo-5H-[1]benzopyrano[2,3-b]pyridines.

5-Oxo-5H-[1]benzopyrano[2,3-b]pyridine-3-carboxylic acids 23 and their tetrazole analogues 24 were synthesized from 4-oxo-4H-1-benzopyran-3-carbonitriles 3 or 2-amino-4-oxo-4H-1-benzopyran-3-carboxaldehydes 4. When administered intravenously, they exhibited antiallergic activity in a reaginic PCA test in rats. In the carboxylic acid series, the activity was influenced by the substituents at the 2-position and increased substantially in the following order: Me, OMe less than NH2 less than OH, H less than NHOMe. On the other hand, in the tetrazole series, 2-unsubstituted derivatives showed the highest activity. Regardless of the kinds of substituents at positions 2 and 3, compounds bearing an alkyl group, especially an isopropyl group at the 7-position, were superior in activity to the corresponding unsubstituted compounds. Among these alkyl derivatives, 3-carboxylic acid derivatives, i.e., 23c (7-ethyl), 23g (2-amino-7-isopropyl), 23r [2-(methoxyamino)-7-isopropyl], and a 3-tetrazole derivative 24c (7-isopropyl), were 41-184 times as potent as disodium cromoglycate. They also exhibited remarkable activity when administered orally; clinical studies on 23g (AA-673) are in progress.

Animals↗
PubMed1985

Inhibition by amoxanox (AA-673) of the immunologically, leukotriene D4- or platelet-activating factor-stimulated bronchoconstriction in guinea pigs and rats.

We studied the effects of amoxanox (AA-673) on allergic asthma and spasmogen-induced bronchoconstriction in guinea pigs and rats. Amoxanox given orally or parenterally inhibited allergic asthma mediated by IgE, IgG1, or heterologous IgG in guinea pigs and by IgE in rats. This compound also reduced leukotriene D4- and platelet-activating factor-induced bronchoconstriction in guinea pigs, strongly suggesting an antagonistic activity against slow reacting substance of anaphylaxis (SRS-A). Histamine- or acetylcholine-induced bronchoconstriction was not significantly affected by amoxanox. These antiasthmatic effects of amoxanox seem to be associated with an inhibition of the release of chemical mediators such as histamine and SRS-A and with an antagonism against SRS-A.

Aminopyridines↗
PubMed1985

Mechanism of the action of amoxanox (AA-673), an orally active antiallergic agent.

Amoxanox inhibited immunologically stimulated and LTD4-induced bronchoconstriction in laboratory animals. Amoxanox, like DSCG, inhibited rat IgE-mediated PCA and histamine release from rat peritoneal mast cells, and suppressed immunologically stimulated or calcium ionophore A23187-induced SRS-A generation in rat peritoneal cavity and guinea pig lung fragments. This compound also reduced the contractile response of guinea pig lung parenchymal and ileal strips to LTD4, but did not significantly affect the response of the ileum to either histamine or acetylcholine. Therefore, the antiallergic action of amoxanox seems to be associated with inhibition of chemical mediator release and antagonistic activity on SRS-A.

Aminopyridines↗