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Biomedical subjects

K Ohno

Publications and source records attributed to K Ohno.

At least 253 records · Page 14Linked to original sources
PubMed1998

Microsurgical reconstruction of the digestive tract following pharyngolaryngectomy and total esophagectomy.

Total pharyngoesophageal reconstruction has remained a challenging field in digestive surgery. During the past 3 years, the authors performed six microsurgical reconstructions of the digestive tract following pharyngolaryngectomy and total esophagectomy due to a multiple cancer or skip metastasis. Digestive continuity was restored using a combination of a pulled-up gastric pedicle and free jejunal transfer in 2 patients, and an elongated gastric pedicle with microvascular augmentation in 4 patients. One elongated gastric pedicle developed partial necrosis, and a free jejunal graft was placed additionally. One patient suffered from respiratory dysfunction and died 1 month after surgery. Postoperative radiographic examination showed a good swallowing mechanism without reflux and stasis in all patients. Microvascular surgery contributes to the successful reconstruction of the digestive tract following extensive pharyngolaryngoesophagectomy.

Aged↗
PubMed1998

Anatomy of microvascular anastomosis in the neck.

Structural and morphometric investigations of the vessels of the neck region were carried out on 30 cadavers (15 male and 15 female in the age range of 45 to 93 years old) to gain more knowledge of the anatomy for microvascular surgery. Our results briefly are as follows: (1) The non-common-truck type of the external carotid artery (in which each branch arises separately from the external carotid artery) was found in 76.6 percent of cases, the truncus linguofacialis type was found in 21.7 percent, and the truncus thyrolingualis type was found in 1.7 percent. (2) The smallest internal diameter (the average was 1.2 mm) was found in the superficial cervical artery. (3) The largest internal diameter (4.4 mm) was measured in the external carotid artery. (4) The longest arterial section (127.8 mm) was measured between the clavicle and mandibular margin. This vascular section or stem consisted of three parts: the supraclavicular part of the common carotid artery, the proximal section of the external carotid artery, and the first 3 cm of the facial artery. (5) In 46.6 percent of cases, the facial, lingual, and superior thyroid veins joined together and formed a thyrolinguofacialis vein. (6) The type with one external jugular vein accounted for 83.0 percent of cases, and the type with one anterior jugular vein for 67.4 percent of cases. (7) The middle thyroid vein exhibited the smallest internal diameter (average of 2.0 mm). (8) The largest internal diameter (7.9 mm) was measured in the internal jugular vein. (9) The longest vessel to receive a vascular pedicle vein was the external jugular vein, the average length of which was 99.7 mm. (10) The frequency and location of valves in the facial vein were also determined.

Aged↗
PubMed1998

In-vitro characterization of YM872, a selective, potent and highly water-soluble alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor antagonist.

The in-vitro pharmacological properties of (2,3-dioxo-7-(1H-imidazol-1-yl)-6-nitro-1,2,3,4-tetrahydro-1-quinoxal inyl)-acetic acid monohydrate, YM872, a novel and highly water-soluble alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)-receptor antagonist were investigated. YM872 is highly water soluble (83 mg mL(-1) in Britton-Robinson buffer) compared with 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline (NBQX), 6-(1H-imidazol-1-yl)-7-nitro-2,3(1H,4H)-quinoxalinedione hydrochloride (YM90K) or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). YM872 potently inhibits [3H]AMPA binding with a Ki (apparent equilibrium dissociation constant) value of 0.096 +/- 0.0024 microM. However, YM872 had very low affinity for other ionotropic glutamate receptors, as measured by competition with [3H]kainate (high-affinity kainate binding site, concentration resulting in half the maximum inhibition (IC50) = 4.6 +/- 0.14 microM), [3H]glutamate (N-methyl-D-aspartate (NMDA) receptor glutamate binding site, IC50 > 100 microM) and [3H]glycine (NMDA receptor glycine-binding site, IC50 > 100 microM). YM872 competitively antagonized kainate-induced currents in Xenopus laevis oocytes which express rat AMPA receptors, with a pA2 value of 6.97 +/- 0.01. In rat hippocampal primary cultures, YM872 blocked a 20-microM AMPA-induced increase of intracellular Ca2+ concentration with an IC50 value of 0.82 +/- 0.031 microM, and blocked 300-microM kainate-induced neurotoxicity with an IC50 value of 1.02 microM. These results show that YM872 is a potent and highly water-soluble AMPA antagonist with great potential for treatment of neurodegenerative disorders such as stroke.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed1998

Detection and sequence analysis of borna disease virus p24 RNA from peripheral blood mononuclear cells of patients with mood disorders or schizophrenia and of blood donors.

Borna disease virus (BDV) p24 RNA was detected in the peripheral blood mononuclear cells (PBMCs) of psychiatric patients and blood donors by nested reverse transcriptase PCR (RT-PCR). The prevalences of BDV p24 RNA in patients with mood disorders (4%) and schizophrenia (4%) were not significantly different from that in blood donors (2%). This finding was inconsistent with previous reports that showed either a high prevalence or absence of BDV p24 RNA in patients with psychiatric disorders. The differences in BDV p24 RNA prevalence in these studies may be due to differences in the criteria for positivity, the number of PBMCs used for RNA extraction, or the amount of RNA tested for nested RT-PCR or to laboratory contamination. Sequence analysis of BDV p24 RNA from the PBMCs of patients and blood donors showed a high nucleotide sequence conservation but definite nucleotide mutations compared with horse BDV p24 RNA sequences. In comparison with human BDV p24 RNA sequences previously reported from Japan and Germany, there were several positions with silent nucleotide mutations among these clones.

Adult↗
PubMed1998

Extrahepatic arterial supply to the liver: observation with a unified CT and angiography system during temporary balloon occlusion of the proper hepatic artery.

PURPOSE: To evaluate routes of potential extrahepatic arterial supply to the liver. MATERIALS AND METHODS: Twenty-three patients with liver tumors underwent computed tomographic (CT) arteriography of extrahepatic arteries before and after temporary balloon occlusion of the proper hepatic artery. The right inferior phrenic artery (RIPA), left inferior phrenic artery (LIPA), superior mesenteric artery (SMA), celiac axis, and left gastric artery (LGA) were evaluated. RESULTS: During temporary balloon occlusion of the proper hepatic artery, extrahepatic arterial supply was immediately evident in 22 of 23 patients (96%). The liver was supplied by the RIPA in 17 of 20 patients (85%), by the LIPA in five of six (83%), by the SMA in eight of 16 (50%), by the celiac axis in two of 10 (20%), and by the LGA in one of six (17%). There was no apparent relationship between the enhanced zones supplied by extrahepatic arteries and the presence or absence of nearby tumors. CONCLUSION: Extrahepatic arterial supply to the liver was readily evident in a large proportion of patients during temporary balloon occlusion of the proper hepatic artery. This finding suggests a need for consideration of extrahepatic arterial supply when angiographic intervention for liver tumors is contemplated.

Aged↗
PubMed1998

The AMPA-receptor antagonist YM90K reduces AMPA receptor-mediated excitotoxicity in rat hippocampal cultures.

The effects of YM90K on alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor-mediated excitotoxicity were investigated using kainate, AMPA and cyclothiazide in rat hippocampal cultures. YM90K had neuroprotective actions against both kainate toxicity and cyclothiazide-enhanced AMPA toxicity. YM90K induced a parallel and rightward shift of both kainate and AMPA dose-response curves. The application of YM90K even 3 hr after the start of kainate exposure significantly reduced kainate toxicity. These results indicate that YM90K protects neurons against AMPA receptor-mediated toxicity at an agonist site on the AMPA receptor and that YM90K protects against AMPA receptor-mediated toxicity even if applied after neurotoxic insult.

Animals↗
PubMed1998

Cholesterol-lowering effects of NTE-122, a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, on cholesterol diet-fed rats and rabbits.

Pharmacological characterization of NTE-122 (trans-1,4-bis[[1-cyclohexyl-3-(4-dimethylamino phenyl)ureido]methyl]cyclohexane), a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, was performed with both in vitro and in vivo assay systems. NTE-122 inhibited microsomal ACAT activities of various tissues (liver of rabbit and rat, small intestine of rabbit and rat, and aorta of rabbit) and cultured cells (HepG2 and CaCo-2), with IC50 values from 1.2 to 9.6 nM. The inhibition mode of NTE-122 was competitive for HepG2 ACAT. NTE-122 had no effect on other lipid metabolizing enzymes, such as 3-hydroxy-3-methylglutaryl-CoA reductase, acyl-CoA synthetase, cholesterol esterase, lecithin:cholesterol acyltransferase, acyl-CoA:sn-glycerol-3-phosphate acyltransferase and cholesterol 7alpha-hydroxylase up to 10 microM. When NTE-122 was administered to the cholesterol diet-fed rats, serum and liver cholesterol levels were markedly reduced with an ED50 of 0.12 and 0.44 mg/kg/day, respectively. In the cholesterol diet-fed rabbits, NTE-122 significantly lowered plasma and liver cholesterol levels at more than 2 mg/kg/day. These results indicate that NTE-122 is a potent, selective and competitive inhibitor of ACAT, making it a worth while therapeutic agent for hypercholesterolemia and atherosclerosis.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗
PubMed1998

Effects of infestation by Rhipicephalus sanguineus on lymphocyte blastogenic responses to mitogens in dogs.

Mitogen blastogenic responses of lymphocytes from dogs infested with adult Rhipicephalus sanguineus and the effects of salivary gland extracts (SGE) of the tick on the blastogenic responses of lymphocytes from normal dogs were studied. Infestation by R. sanguineus significantly suppressed concanavalin A, phyto-hemagglutinin and pokeweed mitogen responses of lymphocytes from dogs. The inhibition of lymphocyte responses of dogs in the first infestation was greater than that in the second infestation. SGE from R. sanguineus also suppressed all mitogen blastogenic responses of lymphocytes from healthy dogs in vitro. These suppressive effects of SGE on the blastogenic responses of PBL to mitogens were significantly inhibited by trypsin digestion. It is suggested that some proteins in SGE contribute to the suppressive effects of SGE on the blastogenic responses of peripheral blood lymphocytes from dogs.

Animals↗
PubMed1998

Effect of interleukin-12 and interleukin-10 on the virus replication and apoptosis in T-cells infected with feline immunodeficiency virus.

Interleukin-12 (IL-12) is an important cytokine for Th1 response which stimulates the T-cell population to produce cytokines for cellular immunity. Interleukin-10 (IL-10) is a pleiotropic cytokine capable of suppressing cytokine production from macrophages and T-cells and participants in Th2 immune response. The present study was carried out to examine the effect of these cytokines on virus replication and apoptosis in T-cells infected with feline immunodeficiency virus (FIV). Infection of a feline T-lymphoid cell line (Fel-039) resulted in an increase of the reverse transcriptase (RT) activity in the culture supernatant accompanied by cell death from apoptosis. Addition of human recombinant IL-12 significantly inhibited the virus replication and apoptosis in Fel-039 cells in a dose dependent manner. Furthermore, the antiviral activity of IL-12 was associated with the expression of IFN-gamma in the FIV-infected Fel-039 cells. In contrast, human recombinant IL-10 did not show any inhibitory effect on the virus replication and apoptosis in the Fel-039 cells infected with FIV. These results suggest that the inhibitory effect of IL-12 on both virus replication and apoptosis has potential implications for the design of immunotherapy strategies using IL-12 in FIV infection.

Adjuvants, Immunologic↗
PubMed1998

Inhibition of apoptosis and virus replication in feline immunodeficiency virus-infected cells by N-acetylcysteine and ascorbic acid.

Infection of feline immunodeficiency virus (FIV) has been shown to induce apoptosis that might be associated with the lymphocyte depletion in the infected cats. To investigate the inhibitory effect of antioxidants on FIV-induced apoptosis, we examined the effect of N-acetylcysteine (NAC) and ascorbic acid (AA) on apoptosis and virus replication in feline lymphoblastoid (Fel-039) and fibroblastoid (CRFK) cell lines infected with FIV. The treatment with NAC or AA induced a significant inhibition of viral replication and apoptosis in Fel-039 cells and tumor necrosis factor alpha (TNF-alpha)-treated CRFK cells infected with FIV. Both cell lines in the presence of noncytotoxic concentrations of NAC or AA showed in increase of intracellular glutathione (GSH) level, which might protect the cells against oxidative stresses exerted by FIV infection and TNF-alpha treatment. On the basis of these in vitro results, we suggest that antioxidant therapies aimed at restoring depleted GSH level might be effective for inhibition of viral replication and cell death associated with the development of immunodeficiency.

Acetylcysteine↗
PubMed1998

[Single and 2-week repeated intravenous dose toxicity studies of disodium mercaptoundecahydro-closo-dodecaborate in rats].

Disodium mercaptoundecahydro-closo-dodecaborate (BSH) is a boron compound used in Boron Neutron Capture Therapy for malignant brain tumors. Intravenous single and 2-week repeated dose toxicity studies of BSH were performed in Sprague-Dawley rats. In the single-dose study, BSH was administered at doses of 100, 300 or 600 mg/kg. Death occurred within 10 min (acute type) or from 5 hr to 2 days (delayed type) after dosing in the 600 mg/kg group. No differences in mortality by sex and dosing speed were observed. Major causes of death were considered to be circulatory disorder in acute death and renal injury in delayed death. The renal injury was observed in the 300 and 600 mg/kg groups. In the 2-week repeated dose study, BSH was administered at doses of 30, 100 or 300 mg/kg/day for 14 days. Body weight gain was suppressed in the 100 and 300 mg/kg groups. One male in the 300 mg/kg group died due to renal and pulmonary lesions at day 8. Slight anemia was observed in the 300 mg/kg group. Pathologically, the kidney showed tubular regeneration with increase of weight in the 300 mg/kg. From these results, the NOAEL of BSH is 30 mg/kg/day.

Animals↗
PubMed1998

Treatment of intracranial abscess in the era of neuroimaging: an analysis of 13 consecutive cases.

We report a series of 13 consecutive patients with intracranial abscess treated at our institution since examination by computed tomography (CT) became available. After various treatments, all abscesses healed. CT has broadened the range of treatment options. Manual puncture was performed in most patients. Stereotactic aspiration through a burr hole, medical therapy alone, or complete excision, including the capsule, via craniotomy may be chosen in cases selected by CT analysis. Individualization of treatment in this disease has become increasingly valuable in effecting a cure.

Adolescent↗
PubMed1998

[The results of recent research in neurocutaneous syndromes].

Identification of NF1, TSC2 and TSC1 genes has enabled us to focus on their function and regulation. Evidence suggests that these genes are tumor suppressor genes. Malignant tissues in NF1 and hamartomatous tissues in TSC show "loss of heterozygosity" in NF1 and TSC1, 2 genes, respectively. In addition, in the Eker rat with hereditary renal carcinoma, a mutation in the TSC2 gene has been identified. In this review I mentioned briefly several issues to be clarified in the near future.

Animals↗
PubMed1998

[Usefulness of enhanced US by CO2 microbubbles for segmental-subsegmental TAE for hepatocellular carcinoma].

Enhanced US by intraarterial infusion of CO2 microbubbles is useful for segmental to subsegmental TAE of hepatocellular carcinoma for several reasons. First, we can obtain better recognition of the tumor stain of hepatocellular carcinoma which is even faint on DSA. Secondly, we can recognize the co-relation between tumor stain and its related segment or subsegment well. Therefore, subsegmental or segmental TAE can be performed easily and precisely using enhanced US by CO2 microbubbles. We noted the bigger advantage of enhanced US by CO2 microbubbles especially in the repeated treated cases of TAE for hepatocellular carcinoma.

Carbon Dioxide↗
PubMed1998

[Arterial redistribution of extrahepatic collaterals to the liver under temporary balloon occlusion of the proper hepatic artery].

Three patients with liver metastases receiving transarterial chemotherapy underwent embolization of extrahepatic collaterals to the liver under temporary balloon occlusion of the proper hepatic artery. Enhancement in the liver and tumors was observed at CT arteriography through the right inferior phrenic artery and was accentuated under balloon occlusion in all patients. A Cyanoacrylate-Lipiodol mixture was infused through the right inferior phrenic artery to occlude arterial communications with intrahepatic arteries. Better contrast agent distribution was obtained in all patients after embolization. It is suggested that this procedure can be effective for arterial redistribution against extrahepatic collaterals to the liver.

Antineoplastic Agents↗