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Biomedical subjects

S Ohba

Publications and source records attributed to S Ohba.

At least 37 records · Page 2Linked to original sources
PubMed2001

Falcotentorial meningioma accompanied by temporal lobe hematoma.

We report a case of a falcotentorial meningioma accompanied by hematoma in the temporal lobe. A healthy 51 year-old-female with no history of hypertension presented with sudden onset of consciousness disturbance and right hemiparesis. Computed tomography revealed a hematoma 5.5 cm in diameter surrounded by thick edematous brain in the left temporal lobe and a tumor 3.5 cm in diameter in the pineal region. Bilateral carotid angiography detected occlusion of the Galenic vein and straight sinus. No causative abnormality of hemorrhage was apparent. However, the left basal vein of Rosenthal had disappeared, and anastomotic venous channels could be observed in the medial left temporal lobe, contiguous to the hematoma. Emergency craniotomy failed to detect any abnormality which could cause hemorrhage in the brain parenchyma surrounding the hematoma. Subtotal removal of the tumor, histologically diagnosed as fibrous meningioma, was achieved three months later employing an occipital transtentorial approach. Venous congestion caused by compression due to the tumor was considered to be one of possible causes of the hemorrhage.

Brain↗
PubMed2001

A small asymptomatic intracranial aneurysm in an elderly woman that ruptured soon after discovery.

A 78-year-old woman underwent magnetic resonance (MR) imaging to assess the deterioration of her right hemiparesis initially caused by putaminal hemorrhage that occurred 5 years prior to referral. MR imaging detected an anterior communicating artery aneurysm but no new lesion was seen that might have caused the deterioration was observed. Hemiparesis improved within several days and she was referred for endovascular treatment of the aneurysm. Digital subtraction angiography demonstrated a 4.4 mm long aneurysm at the A1-A2 junction of her left anterior cerebral artery. Information on the risk associated with treatment caused her to hesitate. Three days after discharge and 40 days after the discovery of the aneurysm it ruptured, causing severe subarachnoid hemorrhage. The patient died on the following day.

Aged↗
PubMed2001

[Diagnosis of acute phase of venous infarction by diffusion-weighted image: case report and review of the literature].

Diffusion-weighted imaging (DWI) can diagnose early stage not only of the arterial infarction but also of venous infarction. We successfully diagnosed a case as acute venous infarction by DWI. The patient, an infant of one year and ten months, presented disturbance of consciousness and left hemiparesis two weeks after dehydration and infections. Computed tomographic scan revealed a cerebral hemorrhage in the right parietal lobe. Cerebral angiography revealed no contrast filling of the posterior side of superior sagittal sinus, straight sinus and transverse sinus. DWI demonstrated a large hyperintensity lesion around the hematoma, suggesting venous infarction in the early stage. We thought that venous infarction was caused by secondary extension of thrombus to cerebral cortical veins and deep cerebral veins. External decompression and postoperative hypothermia therapy were performed because of rapidly deteriorating intracranial hypertension. Intracranial hypertension was, however, uncontrollable. The patient died four days after the onset. Diagnosis of the venous infarction by DWI was discussed along with other recent reports. Diffusion hyperintensity was displayed in almost all subjects with acute venous infarction. DWI pattern of venous infarction is more heterogeneous than that of arterial one because pathway from venous obstruction to infarction is complicated.

Cerebral Infarction↗
PubMed2001

[A case of squamous cell carcinoma of the oral floor showing a complete response to oral administration of UFT].

A 73-year-old male with squamous cell carcinoma of the oral floor (T1N0M0), who had not consented to radical treatment was treated with UFT by oral administration alone. After commencement of the administration, tumor remission was observed at 2 weeks and disappeared clinically at 8 weeks. The total period of oral administration of UFT was twenty-three months, and the total dose was 186.5 g as tegafur. Major adverse effects were pigmentation of hands and liver dysfunction. He remains under observation, and there is no evidence of tumor recurrence.

Administration, Oral↗
PubMed2000

One-Pot synthesis of photochromic naphthopyrans in the solid state

p-TsOH-catalyzed condensation reactions of 1,1-diaryl-2-propyn-1-ol (1) and 2-naphthol (2) in the solid state gave 3, 3-diaryl-3H-naphtho[2,1-b]pyran (6) via Claisen rearrangement. Similar reactions of 1 with 2,6- (7) and 2,7-dihydroxynaphthalenes (8) afforded naphthodipyrane derivatives 9 and 10, respectively. Bis-naphthopyran derivatives 12 were also obtained by the reaction of 1,1,6,6-tetraaryl-2,5-hexadiyn-1,6-diol (11) and 2-naphthol (2) in the solid state.

Journal Article↗
PubMed2000

1,3-Propanediammonium bis(3'-nitro-trans-cinnamate) and trans-1,2-cyclohexanediammonium bis(3'-nitro-trans-cinnamate).

In the title two adducts, C(3)H(12)N(2)(2+).2C(9)H(6)NO(4)(-), (I), and C(6)H(16)N(2)(2+).2C(9)H(6)NO(4)(-), (II), hydrogen bonds between the diammonium and carboxylate ions form a two-dimensional network parallel to the ab plane in (I) and one-dimensional chains along the c axis in (II). The cyclohexanediammonium ion in (II) has a crystallographic twofold axis.

Journal Article↗
PubMed2000

Design and synthesis of a more highly selective ammonium ionophore than nonactin and its application as an ion-sensing component for an ion-selective electrode

A novel ammonium ionophore, which exhibits superior NH4+ selectivity compared with that of the natural antibiotic nonactin, was successfully designed and synthesized based on a 19-membered crown compound (TD19C6) having three decalino subunits in the macrocyclic system. This bulky decalino subunit is effective for (1) increasing the structural rigidity of the cyclic compound, (2) introducing the "block-wall effect", which prevents forming a complex with a large ion, and (3) increasing the lipophilicity of the ionophore molecule. In the ammonium ionophore design, the first factor contributes to increasing the NH4+ selectivity relative to smaller ions such as Li+, Na+, or even the closest size, K+, and the second factor increases the NH4+ selectivity over larger ions such as Rb+ and Cs+. The X-ray structural analysis proved that TD19C6 forms a size-fit complexwith NH4+ in its crown ring cavity. As an application of this ionophore, an ion sensor (ion-selective electrode) was prepared, which exhibited NH4+ to K+ and Na+ selectivity of 10 and 3,000 times, respectively. This electrode showed a better performance compared to the electrode based on nonactin, which is the only ammonium ionophore presently used in practical applications.

Journal Article↗
PubMed2000

Tetra-micro-acetato-O:O'-bis[(7-azaindole-N)copper(II)].

The title complex, [Cu(2)(C(2)H(3)O(2))(4)(C(7)H(6)N(2))(2)], shows a binuclear cage structure having an inversion centre. There are intramolecular N-H.O hydrogen bonds between the 7-azaindole ligands and the bridging acetate O atoms.

Journal Article↗