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Biomedical subjects

K Ohno

Publications and source records attributed to K Ohno.

At least 235 records · Page 13Linked to original sources
PubMed1998

[Mediastinoscopic diagnosis and drainage of pericardial diverticulum--a case report].

A 38-year-old male was suspected of having an enlarged pretracheal lymph node on chest CT scan. At mediastinoscopy, a cystic lesion was recognized, and showed repeated dilatation and contraction synchronously with the cardiac beat. Pneumopericardium was demonstrated by intraoperative pneumocystography. The cystic lesion was diagnosed as pericardial diverticulum. The diverticular wall was partially resected for drainage of the pericardial fluid. Mediastinoscopy as a less invasive procedure may be useful for the differential diagnosis of adenopathies, and in case of lesion such as a small pericardial diverticulum may allow treatment.

Adult↗
PubMed1998

[A successfully treated case of empyema with a large tracheal fistula after subtotal esophagotomy by mediastinoscopy].

We reported a successfully treated case of empyema with a large tracheal fistula after subtotal esophagotomy. This 59-year-old male was treated by drainage with mediastinoscopy and repeated wash-out under bronchoscopy, because we could not use the omentum and he was the poor-risk patient. The trancheal fistula was obliterated bronchoscopically, 4 months after the mediastinoscopy. We believe that this method (abscess drainage with mediastinoscope and wash-out repeatedly) is useful for those who has broncheal fistula after esophagectomy.

Bronchial Fistula↗
PubMed1998

[Mediastinoscopic drainage for descending necrotizing mediastinitis].

A case of descending necrotizing mediastinitis that was treated by mediastinoscopic drainage is reported. The patient was a 56-year-old diabetic woman. A hypopharyngeal abscess extended to the mediastinum through the neck. No septic condition was noted. Chest CT showed that the abscess reached 4 cm below the tracheal bifurcation. Pus was drained under direct observation by mediastinoscopy, and a drain was placed in an appropriate position. After operation, lavage was performed through the drain, and cure was achieved on the 42nd postoperative day. This technique should be considered as surgical treatment for descending necrotizing mediastinitis in the absence of serious complication such as sepsis, because it has a more reliable drainage effect than the conventional transcervical method, and because it is less invasive than thoracotomy.

Drainage↗
PubMed1998

Chest wall repair with a titanium instrument.

We performed chest wall repair with titanium alloy instruments as artificial ribs for prevention of paradoxical respiration and protection of the lung and liver after chest wall resection including the nearly entire length of the right seventh to the eleventh ribs and the costal arch for metastasis of osteosarcoma. The technique of this operation is presented diagrammatically.

Adolescent↗
PubMed1998

The cooperative effect of interferon-alpha and ribavirin on subacute sclerosing panencephalitis (SSPE) virus infections, in vitro and in vivo.

We studied the effects of two antiviral agents, human interferon-alpha (IFN-alpha) and ribavirin, on subacute sclerosing panencephalitis (SSPE) virus infections in hamsters. By intracranial administration, IFN-alpha alone improved the survival of infected hamsters by 20% at a dose of 6 x 10(4) IU/kg every other day for 10 days. When the dose of IFN-alpha was increased incrementally to 6 x 10(6) IU/kg, the survival rate increased by 70% in a dose-dependent manner. The combination of IFN-alpha and ribavirin had a synergic inhibitory effect on the replication of SSPE virus in cell culture. Combination of IFN-alpha (at a dose of 6 x 10(5) IU/kg) with ribavirin (at a dose of 1 mg/kg) completely prevented mortality. This was significantly better than either IFN-alpha or ribavirin monotherapy (p < 0.05). Under the conditions used, IFN-alpha did not enhance the toxicity of ribavirin in hamsters. Intraventricular administration of high dose IFN-alpha and ribavirin may have potential usefulness in the treatment of patients with SSPE.

Animals↗
PubMed1998

Characterization of cyclothiazide-enhanced kainate excitotoxicity in rat hippocampal cultures.

Cyclothiazide has been shown to block desensitization of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-preferring receptors and to enhance quisqualate-, AMPA- and kainate-induced neurotoxicity. The pharmacology behind this cyclothiazide-enhanced kainate-induced excitotoxicity was characterized in embryonic rat hippocampal cell cultures. Treatment of cell cultures with a combination of cyclothiazide and kainate for 24 h resulted in excessive neuronal death as measured by the release of lactate dehydrogenase into the culture media. Cyclothiazide produced a leftward shift of the kainate dose-response curve and enhanced the maximum response of kainate excitotoxicity. AMPA-preferring receptor antagonists, 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline(NBQX) and 1-(4-amino-phenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine (GYKI 52466) blocked cyclothiazide-enhanced kainate toxicity completely, and cyclothiazide increased the IC50S for NBQX and GYKI 52466 against kainate toxicity. The N-methyl-D-aspartate (NMDA) antagonist, (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5,10-imine (MK801) also blocked cyclothiazide-enhanced kainate toxicity, but only partially. Cyclothiazide also increased the IC50 for MK801 against kainate toxicity. These data suggest that cyclothiazide enhances both AMPA-preferring receptor- and NMDA receptor-mediated toxicity in kainate-induced toxicity in embryonic rat hippocampal cultures.

Animals↗
PubMed1998

Accumulation of cholesterol and GM2 ganglioside in cells cultured in the presence of progesterone: an implication for the basic defect in Niemann-Pick disease type C.

Cultured fibroblasts from patients with Niemann-Pick disease type C (NP-C) are characterized by lysosomal accumulation of unesterified cholesterol and a defect in intracellular trafficking of cholesterol. We have found the accumulation of GM2 ganglioside in NP-C fibroblasts [Yano T, Taniguchi M, Akaboshi S, Vanier MT, Tai T, Sakuraba H, et al. Proc Japan Acad 1996;72B:214-219]. In this communication we show that several inhibitors known to inhibit intracellular cholesterol transport, progesterone, imipramine and KN-62, elicit accumulation of not only unesterified cholesterol but also GM2 ganglioside. This finding suggests that intracellular transport of cholesterol may be coupled with that of GM2 ganglioside. The accumulation of free cholesterol and GM2 ganglioside may be a clue for understanding the basic defect of NP-C. Recently NPC1 gene is found by the positional cloning. The mechanism of accumulating of GM2 ganglioside should be further investigated by studying of the functions of NPC1 gene.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1998

Increased levels of GM2 ganglioside in fibroblasts from a patient with juvenile Niemann-Pick disease type C.

A 15-year-old boy was suffering from splenomegaly and a 10-year history of a neurologic disorder that included mental retardation, vertical supranuclear gaze palsy, dysarthria, ataxia, and dystonia. Bone marrow aspirates revealed foamy cells with storage materials which were positive with filipin staining. Cultured skin fibroblasts derived from the patient showed moderate loss of sphingomyelinase activity and the impairment of cholesterol esterification. The characteristic clinical presentations and typical histochemical findings of this patient met the diagnostic criteria of Niemann-Pick disease type C (NPC). In the fibroblasts from the patient, there was an accumulation of GM2 ganglioside around their cytoplasms. Increased levels of glycolipids. including GM2 ganglioside are reported in the cerebral cortex of NPC, but not in the fibroblasts. The fibroblasts derived from NPC may reflect the abnormal metabolism of glycolipids in the central nervous system of NPC.

Adolescent↗
PubMed1998

Increased expression of beta-hexosaminidase alpha chain in cultured skin fibroblasts from patients with carbohydrate-deficient glycoprotein syndrome type I.

Carbohydrate-deficient glycoprotein (CDG) syndrome type I is an autosomal recessive multisystem disorder characterized by multiple serum glycoproteins with deficient oligosaccharide chains. This characteristic under-glycosylation is found in several serum glycoproteins. We studied secreted forms of lysosomal enzymes, beta-hexosaminidase and alpha-fucosidase, in serum from the patients and media of cultured fibroblasts. Both beta-hexosaminidase and alpha-fucosidase activities were increased in sera from three CDG patients. The enzyme activity staining using the fluorogenic substrate-4-methylumbelliferyl-alpha-L-fucopyranoside after polyacrylamide gel isoelectric focusing revealed abnormal cathodal bands in sera from CDG patients. On the other hand, no abnormal secreted forms of beta-hexosaminidase and alpha-fucosidase were detected in media from cultured CDG fibroblasts by isoelectric focusing and sodium-dodecyl sulfate-polyacrylamide gel electrophoresis. However, SDS-polyacrylamide gel electrophoresis and Western blotting analysis of beta-hexosaminidase using anti-beta-hexosaminidase A (anti-alpha + beta chains) antibody, showed an increase of a 55-kDa mature form of the alpha chain. Northern blotting analysis identified an increase in mRNA levels of beta-hexosaminidase alpha chain in CDG fibroblasts. Although under-glycosylated fractions of these lysosomal enzymes were not detected in cultured fibroblasts, it was suggested that intracellular processing of these lysosomal enzymes in CDG patients might be altered.

Blotting, Northern↗
PubMed1998

New syndrome with the Sakoda complex, bilateral anophthalmia, and cortical dysgenesis.

An 8-year-old Japanese boy had Sakoda complex (basal encephalomeningocele, agenesis of the corpus callosum, and cleft lip and/or palate) associated with bilateral anophthalmia, dysgenesis of the cerebral cortex, severe mental retardation, and intractable epilepsy as core symptoms and hemiparesis, microcephalus, short stature, and hemivertebra. Tada and Nakamura described the first case of the Sakoda complex associated with bilateral anophthalmia, cortical dysgenesis, neonatal-onset seizures, and severe mental retardation. Fourteen patients with the Sakoda complex with or without ocular dysplasia were reviewed. It is proposed that these cases belong to a clinical entity that is distinguishable from the remaining 12 patients because of bilateral anophthalmia, cortical dysgenesis, and its resulting severe mental retardation and intractable epilepsy. There is a possibility that these two cases are one severe end of certain spectrum disorders in which certain common gene(s) might be implicated.

Abnormalities, Multiple↗
PubMed1998

Epidemiology of spina bifida in Tottori Prefecture, Japan, 1976-1995.

The authors studied the epidemiology of spina bifida in Tottori Prefecture, Japan, from 1976 to 1995. Thirty-four patients (16 men and 18 women) were registered in this study. Consanguineous marriages, familial occurrence, and abnormalities in prenatal history were not observed. The incidence rate in the entire prefecture and in the eastern, central, and western regions was 0.234, 0.148, 0.425, and 0.230 per 1,000 live births, respectively. The incidence rate in the central region was greater than that in the eastern region with statistical significance (P < 0.05), but the cause of the cluster is unknown. The incidence rate of 0.234 per 1,000 live births for 20 years is compatible with the previous two studies of 1922-1940 and 1948-1954 in Japan. Such apparently stable trends suggest that environmental factors have affected the Japanese less than genetic factors. Seasonal variations are not demonstrated.

Demography↗
PubMed1998

Mode switching kinetics produced by a naturally occurring mutation in the cytoplasmic loop of the human acetylcholine receptor epsilon subunit.

We describe the genetic and kinetic defects in a congenital myasthenic syndrome caused by heteroallelic mutations of the acetylcholine receptor (AChR) epsilon subunit gene. The mutations are an in-frame duplication of six residues in the long cytoplasmic loop (epsilon1254ins18) and a cysteine-loop null mutation (epsilonC128S). The epsilon1254 ins18 mutation causes mode switching in the kinetics of receptor activation in which three modes activate slowly and inactivate rapidly. The epsilon1245ins18-AChR at the endplate shows abnormally brief activation episodes during steady state agonist application and appears electrically silent during the synaptic response to acetylcholine. The phenotypic consequences are endplate AChR deficiency, simplification of the postsynaptic region, and compensatory expression of fetal AChR that restores electrical activity at the endplate and rescues the phenotype.

Acetylcholine↗
PubMed1998

Congenital myasthenic syndromes: experiments of nature.

Congenital myasthenic syndromes (CMS) can arise from presynaptic, synaptic, or postsynaptic defects. Recent studies indicate that mutations in the acetylcholine receptor (AChR) subunit genes are a common cause of the postsynaptic CMS. The mutations, which increase or decrease the response to acetylcholine, are experiments of nature that highlight functionally significant domains of the AChR.

Frameshift Mutation↗
PubMed1998

The use of two immunosuppressive drugs, cyclosporin A and tacrolimus, to inhibit virus replication and apoptosis in cells infected with feline immunodeficiency virus.

An in vitro model of acute and chronic infections with feline immunodeficiency virus (FIV) was used to examine the effect of two immunosuppressive agents, cyclosporin A (CsA) and tacrolimus (also known as FK506), on the inhibition of the replication of the virus and of apoptosis. Both drugs significantly suppressed virus production in a dose-dependent manner in acutely and chronically infected cells. The ability of FK506 to inhibit virus replication was much lower than that of CsA, and was accompanied by marked antiproliferative activity. Treatment of infected cells with either CsA or FK506 did not affect the rise of free intracellular Ca2+ but did protect the cells against apoptosis. Thus, the antiviral activity of CsA and FK506 makes these compounds promising candidates for the development of drugs suitable for the treatment of AIDS.

Animals↗
PubMed1998

Expression pattern analysis of SGF-3/POU-M1 in relation to sericin-1 gene expression in the silk gland.

Embryonic and larval expression patterns of the sericin-1 gene and its presumed transcription factor, SGF-3/POU-M1, in the silk gland were analyzed by in situ hybridization and immunohistochemistry. The sericin-1 transcripts were first detected at embryonic stage 26 in an increasing gradient pattern in the middle and posterior part of the middle silk gland (MSG), while at the same stage the SGF-3/POU-M1 was already present in the entire anterior silk gland (ASG) and in the MSG but with a decreasing gradient pattern. The latter expression pattern was consistently maintained through all larval stages, while the sericin-1 expression was detected during the feeding stages but disappeared at the molting stages. These observations suggest that, although the SGF-3/POU-M1 was proposed to be a positive transcription factor for the sericin-1 gene, the protein might function in a negative manner on sericin-1 gene transcription. Alternatively, it is also possible that the sericin-1 gene might require another unidentified factor or mediator for in vivo transcription.

Animals↗
PubMed1998

Characterization of cytochrome P450 (CYP3A12) induction by rifampicin in dog liver.

1. Effects of rifampicin (Rif) on the contents of cytochrome P450 (P450) enzymes (CYP1A1/2, 2B11, 2C21 and 3A12) assessed by enzyme-linked immunosorbent assay and catalytic activities (ethoxyresorufin O-deethylase, and testosterone 6 beta-, 16 alpha- and 16 beta-hydroxylase; 6 beta-, 16 alpha- and 16 beta-OHT) in dog liver microsomes were compared between liver lobes of both the male and female dogs. 2. In the control dogs, the contents of individual P450 enzymes and their activities showed no significant differences between individual liver lobes and between the sexes. 3. Rif treatment (10 mg/kg/day, p.o. for 7 days) induced substantial increases in the content of CYP3A12 and 6 beta- and 16 beta-OHT activities, and slight increases in the content of CYP2B11 and 16 alpha-OHT activity, and their elevated levels were virtually the same between liver lobes. The magnitudes of the elevation of the CYP3A12 level and 6 beta- and 16 beta-OHT activities compared with control levels appeared to be greater in the female dogs. However, the ratios of their magnitudes (CYP3A content/6 beta-OHT activity and CYP3A content/16 beta-OHT activity) showed no differences between the sexes. 4. In both the control and Rif-treated dogs, the activities of 6 beta- and 16 beta-OHT were specifically inhibited by anti-CYP3A12 antiserum, and 16 alpha-OHT activity was specifically inhibited by anti-CYP2B11 and anti-CYP2C21 antiserum. 5. These results indicate that Rif treatment induces the expression of CYP3A12 protein, and correlates well with the elevation of its catalytic activity (6 beta- and 16 beta-OHT), and that the female dog is more responsive to Rif treatment as compared with the male.

Animals↗
PubMed1998

Use of intraperitoneal vessels in reconstructive microsurgery: an account of 117 cases.

The purpose of this study was to evaluate our experience of microvascular anastomosis of intraperitoneal vessels. Between 1985 and 1994, 117 microsurgical reconstructions were done using intraperitoneal vessels. These included oesophageal reconstruction (n = 106), reconstruction of the hepatic arterial, superior mesenteric arterial, or portal venous system (n = 8), and reconstruction of the chest or abdominal wall (n = 3). We used 129 intraperitoneal arteries and 117 intraperitoneal veins. Of a total of 246 intraperitoneal vessels, five hepatic arteries, seven splenic, 14 gastroepiploic, six superior mesenteric, 178 jejunal, 30 ileocolic, four middle colic arteries or veins, and two portal veins were used for microvascular anastomosis. The overall successful rate for these reconstructive cases was 97% (114/117). Microsurgical use of intraperitoneal vessels is a safe and developing procedure in plastic and reconstructive surgery.

Adult↗