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Biomedical subjects

K Ohno

Publications and source records attributed to K Ohno.

At least 649 records · Page 36Linked to original sources
PubMed1986

Direct measurement of the electrogenicity of the H+-ATPase from thermophilic bacterium PS3 reconstituted in planar phospholipid bilayers.

The proton-translocating ATPase of the thermophilic bacterium PS3 was incorporated into a planar phospholipid bilayer, and its electrogenicity was directly demonstrated. The enzyme (TF0F1) consists of a catalytic portion, F1, and a membrane-integrated portion, Fo. A short-circuit current of up to 1 nA/cm2 was generated upon the addition of ATP, and the direction of the current indicated the flow of positive charges from the TF1 side to the TF0 side. The generation of the electric current was progressively suppressed by the presence of an inhibitor of TF1 such as NaN3 or adenyl-5'-yl imidodiphosphate. An open-circuit membrane potential of 40-120 mV was also demonstrated (more negative on the TF1 side), which was inhibited by NaN3. Furthermore, an applied voltage of -180 mV (TF1 side negative) was sufficient to prevent the generation of electric current dependent on ATP hydrolysis, which indicated that the electrogenicity of TF0F1 is some 180 mV under the conditions studied. From these results it was tentatively concluded that the number of protons transported across the bilayer/mol of ATP is more than 3.

Adenosine Diphosphate↗
PubMed1986

Ultrasonography of mediastinal teratoma.

We have studied real-time sonograms of 11 surgically proven benign mediastinal teratomas. Eight cystic teratomas were sonographically visualized as various kinds of masses: four complex, two solid, and two cystic. The echo patterns of cystic teratomas were determined by the serous or nonserous nature of the cysts. In the presence of serous fluid, the tumor was visualized as a cystic mass. If, on the other hand, the cyst of the tumor was nonserous or was sebaceous, it appeared as a solid or complex tumor. The remaining three solid teratomas, which had some small cysts, appeared as complex tumors.

Adult↗
PubMed1986

Relationship between oxidative metabolites of hydrazine and hydrazine-induced mutagenicity.

Hydrazine (Hz) mutagenicity was observed in a test using Escherichia coli B/r strain, WP2 uvrA and was enhanced by the addition of rat liver microsomal fraction containing a generating system, while the enhanced mutagenicity was diminished by the addition of metyrapone to the microsome-free levels. On the other hand, an NADPH-dependent difference spectrum of the metabolic intermediate of Hz-complex, characterized by a maximum level of 448 nm, was also inhibited by metyrapone. The results show that the oxidative intermediates, which are diimide and its precursor, hydrazine free radical [Biochem. Biophys. Res. Commun., 133 (1986) 1086], are responsible not only for hepatotoxicity but also for the enhancement of genotoxicity or mutagenicity.

Animals↗
PubMed1986

Clinical characteristics and prognosis of myasthenia gravis with other autoimmune diseases.

Of 277 patients with myasthenia gravis (MG) who underwent thymectomy, including 78 with thymomatous MG, 33 patients had other autoimmune diseases. The clinical characteristics of MG with other autoimmune disease were investigated. Graves's disease and rheumatoid arthritis were the most common autoimmune diseases seen. The association rate of autoimmune disease in patients with thymomatous MG (3.8%) was significantly lower than that in patients with nonthymomatous MG (15.1%). The positive rate for a germinal center in the thymus was significantly higher in patients with other autoimmune disease than in those without such disease. Thymectomy was effective for MG in patients with an associated disease as well as in those without such a complication. The clinical course of the associated autoimmune disease did not seem to be adversely affected by thymectomy. Therefore, thymectomy should be performed in MG patients with other autoimmune disease.

Arthritis, Rheumatoid↗
PubMed1986

The syndrome of the absence of a septum pellucidum with porencephaly.

Two cases of a complex brain malformation including the absence of a septum pellucidum and bilateral porencephaly were reported and compared with Aicardi's cases. The two cases have congenital hemiplegia or double hemiplegia and mental retardation, and one of them has optic atrophy. CT scans revealed the absence of a septum pellucidum and a specific position and shape of the clefts. The syndrome of the absence of a septum pellucidum and porencephaly may represent a specific type of true porencephaly, and the cause must occur before 16 weeks of gestation.

Adolescent↗
PubMed1986

[Massive osteoplastic bone metastasis of hepatocellular carcinoma--a case report].

Massive osteoplastic bone tumor in hepatocellular carcinoma is very rare. A 48-year-old man was misdiagnosed as osteosarcoma of the right proximal tibia with dense sclerosis and marked periosteal spiculation. Histologically, there were many osteoids and immature trabeculi. Tumor cells with spindle nuclei were not atypical and had few mitoses. Three years later, he suddenly died of rupture of cerebral aneurysm. Autopsy revealed small hepatocellular carcinoma with distant metastases of the tibia, lumbar spine and lung. In this case, it was extremely difficult to decide whether or not we were dealing with primary malignant tumor.

Bone Neoplasms↗
PubMed1986

Role of traumatic subdural fluid collection in developing process of chronic subdural hematoma.

We investigated the role of traumatic subdural fluid collection in the genesis of chronic subdural hematoma (CSDH) in 43 consecutive patients with traumatic subdural fluid collection. Traumatic subdural fluid collection was found in 43 (6%) of 715 patients who underwent CT scans because of head injury. Twenty-four of the 43 patients were more than 65 years of age and this problem occurred in 30% of the 79 head-injured patients over 65 years of age. In 20 (Group 1) of the 43 patients CSDH subsequently developed. During the same period, 30 other patients were treated for CSDH. Twenty-four (Group 2) of these 30 patients had a history of head injury more than two weeks prior to the developing signs and symptoms and had hyper- or iso-dense hematomas on their first CT scan. It may have been that they too first had a traumatic subdural collection. Forty to sixty percent of the patients with asymptomatic traumatic subdural fluid collection may develop CSDH, and this may occur especially in the older patients. Careful observations after the head injury are particularly important in the aged because of the frequent occurrence of traumatic subdural fluid collection and the subsequent development of CSDH.

Adult↗
PubMed1986

[Congenital absence of the anterior compartment muscle of both legs--a case report].

A case of the congenital defect of the anterior compartment of the legs is reported, and is the first one in the literature. This case presented bilateral talipes equinovarus deformity at birth on a sister of identical twins. The abnormalities of the leg muscles were found from lack of active dorsiflexion of the ankle and the toes after initial walking. In the surgical finding, the deep peroneal nerve was normal, but the anterior compartment muscles of the leg were completely replaced by the fatty tissue. Microscopically, the normal muscle fibers were scattered in the fatty tissue with the small vessels and the nerve fibers. The etiology of the congenital muscle defect has been in controversy, but as yet there have been few case reports of lower leg muscle defect. In the treatment of congenital club foot, one should consider the congenital defect of the anterior compartment muscles.

Clubfoot↗
PubMed1986

Site and mechanism of growth inhibition by prostaglandins. II. Temperature-dependent transfer of a cyclopentenone prostaglandin to nuclei.

Cyclopentenone prostaglandins (PGs) such as PGA2 and 9-deoxy-delta 9,12-13,14-dihydro-PGD2 (delta 12-PGJ2) are transported actively into the cytoplasm and exert growth inhibition in cultured cells. We examined effect of temperature on the uptake of delta 12-PGJ2 and its subsequent translocations within and out of the cells. When L-1210 murine leukemia cells were incubated with the PG at 4, 20 and 37 degrees C, the initial rate of uptake increased with temperature. However, the uptake at 37 degrees C declined rapidly after 5 min, whereas that at 4 and 20 degrees C increased linearly and reached plateau. Subcellular distribution study revealed that about 90% of the radioactivity taken up at 4 and 20 degrees C was present in the cytoplasm, whereas more than 50% of the radioactivity transported at 37 degrees C accumulated in the nuclei. When incubation temperature was shifted from 4 to 37 degrees C during incubation, significant accumulation of the radioactivity in the nuclei occurred at 37 degrees C. In contrast, when the cells were first incubated with delta 12-PGJ2, then washed and incubated without the PG at either 20 or 37 degrees C, most of the radioactivity found in the cytoplasm was effluxed to the medium during the second incubation. The rate of this efflux was negligible at 4 degrees C but increased with temperature above 20 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗