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Biomedical subjects

T Ohashi

Publications and source records attributed to T Ohashi.

At least 19 recordsLinked to original sources
PubMed1992

Efficient transfer and sustained high expression of the human glucocerebrosidase gene in mice and their functional macrophages following transplantation of bone marrow transduced by a retroviral vector.

A recombinant retroviral vector (MFG-GC) was used to study the efficiency of transduction of the human gene encoding glucocerebrosidase (GC; D-glucosyl-N-acylsphingosine glucohydrolase, EC 3.2.1.45), in mouse hematopoietic stem cells and expression in their progeny. Transfer of the GC gene to CFU-S (spleen cell colony-forming units) in primary and secondary recipients was virtually 100%. In mice 4-7 months after transplantation, highly efficient transfer of the human gene to bone marrow cells capable of long-term reconstitution was confirmed by detection of one or two copies per mouse genome in hematopoietic tissues and in cultures of pure macrophages. Expression of the human gene exceeded endogenous activity by several fold in primary and secondary CFU-S, tissues from long-term reconstituted mice, and explanted macrophages cultures. These studies are evidence of the feasibility of efficient transfer of the GC gene to hematopoietic stem cells and expression in their progeny for many months after reconstitution. The results of this study strengthen the rationale for gene therapy as a treatment for Gaucher disease.

Animals↗
PubMed1992

Elevation of feline interleukin 6-like activity in feline immunodeficiency virus infection.

The involvement of feline interleukin 6 (IL-6)-like activity in polyclonal B-cell activation in feline immunodeficiency virus (FIV) infection was investigated by using the proliferative response of hybridoma cell clone B3B1. Cats spontaneously infected with FIV had hyperimmunoglobulinemia, as shown by increases in the percentage of gamma-globulin and the plasma IgG concentration and decrease in the albumin/globulin (A/G) ratio. Because IL-6 plays an essential role in the differentiation of activated B cells into Ig-secreting cells, we examined the effect of FIV infection on the plasma IL-6 level. Plasma IL-6-like activity was found to be significantly higher in FIV-infected cats than in healthy controls. Peripheral blood mononuclear cells (PBMC) isolated from FIV-infected cats and cultured without any exogenous activators of IL-6 production released more feline IL-6-like activity than cells from healthy controls. This phenomenon was mainly due to the increase in the production of IL-6 by adherent cells such as monocytes/macrophages, but also partly by nonadherent cells. These results indicate that elevation of feline IL-6-like activity is associated with FIV infection and that overproduction of IL-6 may contribute to the polyclonal B-cell activation seen in FIV infection.

Animals↗
PubMed1992

Ocular torsion produced by unilateral chemical inactivation of the interstitial nucleus of Cajal in chronically labyrinthectomized cats.

Unilateral lesions of the rostral midbrain involving the interstitial nucleus of Cajal (INC) have been known to produce ocular torsion in alert animals including humans, which has been assumed to be the result of an impaired otolith-ocular reflex. We examined the effects of chemical deactivation of the INC using a gamma-aminobutyric acid (GABA) agonist (muscimol) in cats that had received bilateral labyrinthectomy, and compared the results with those in normal cats. Ocular torsion with a magnitude similar to that observed in normal cats appeared in chronically labyrinthectomized cats after unilateral muscimol infusion into the INC, indicating that ocular torsion following unilateral INC deactivation can be produced by a mechanism independent of the otolith-ocular reflex.

Animals↗
PubMed1992

Detection of the thermostable direct hemolysin gene (tdh) and the thermostable direct hemolysin-related hemolysin gene (trh) of Vibrio parahaemolyticus by polymerase chain reaction.

Polymerase chain reaction (PCR) protocols were established for specific detection of the tdh and trh genes, the virulence marker genes of Vibrio parahaemolyticus encoding two related hemolysins. The tdh and trh genes are known to have sequence divergence of up to 3.3% and 16%, respectively. Attempts were made to find suitable primer pairs and annealing temperatures to detect each gene without fail. DNAs extracted from 36 representative strains of V. parahaemolyticus were used in the initial screening with various combinations of primer pairs and annealing temperatures. The combinations of primer pairs and annealing temperatures selected were then tested with DNAs extracted from 227 more strains of V. parahaemolyticus and from 133 bacterial strains belonging to 40 species other than V. parahaemolyticus. PCR protocols (primer pairs and annealing temperatures) were established that gave identical results to those obtained with the tdh- and trh-specific polynucleotide probes. These protocols established for the tdh and trh genes could detect 400 fg (100 cells) of cellular DNA carrying the respective gene. Spike experiments demonstrated that the sensitivities of the established PCRs were reduced by a factor of 10(4)-10(5) by an inhibitor(s) present in a normal faecal sample, indicating the need for either DNA extraction or enrichment of the faecal sample in alkaline peptone water for 4 h before the PCR of faecal samples.

Base Sequence↗
PubMed1992

Non-isotopic microtitre plate-based assay for detecting products of polymerase chain reaction amplification: application to detection of the tdh gene of Vibrio parahaemolyticus.

A non-isotopic microtitre plate-based assay method was devised for detection of products of the polymerase chain reaction. This assay involves affinity immobilization of the biotinylated amplification products in microtitre plate wells and their fluorescence detection by their hybridization with an oligonucleotide probe linked to alkaline phosphatase. An advantage of this procedure is that the immobilization and hybridization are carried out simultaneously in the wells, thus shortening the assay time. The assay method was applied to the detection of the tdh gene of Vibrio parahaemolyticus. Seven copies of the target chromosome could be detected in about 45 min after 35 cycles of amplification.

Alkaline Phosphatase↗
PubMed1992

[Studies on zwitter-ionization of drugs. I. Synthesis and pharmacological activities of N-alkylcarboxylic acid derivatives of 4-(2-chlorodibenz-[b,f][1,4]oxazepin-11-yl)piperazine, 4-(2-chlorodibenzo[b, f]-[1,4]thiazepin-11-yl)piperazine, and 4-(11H-dibenz-[b,e]azepin-6-yl)piperazine].

The piperazine N-alkylcarboxylic acids of 2-chlorodibenz[b,f][1,4] oxazepine (3a), 2-chlorodibenzo[b,f] [1,4] thiazepine (3b), and dipenz[b,e] azepine (3c) from the corresponding piperazines (1a-c, R1 = H) were synthesized via the piperazine N-alkylcarboxylates (2a-c). The pharmacological activities of the piperazine N-alkylcarboxylic acids (3a-c) were evaluated. Compared with the parent compounds (1a-c), 3a-c (n = 1-5) showed weak inhibitory activities on the uptake of noradrenaline and 5-hydroxytryptamine (5-HT) into hypothalamus vesicles and moderate antagonistic actions to 5-HT2 and H1 in several tissues.

Amoxapine↗
PubMed1992

Intracavernous cavernous hemangioma: dynamic CT findings and effectiveness of irradiation--case report.

An intracavernous cavernous hemangioma occurred in a 34-year-old female presenting with amenorrhea and hyperprolactinemia. Computed tomography (CT) showed a homogeneously enhanced mass in the right cavernous sinus. The time-density curve detected by dynamic CT showed significant delayed flow in the lesion. The mass was significantly reduced in size by local irradiation (50 Gy). Dynamic CT may be useful in differentiating cavernous hemangioma, and radiation therapy should be considered for preferred treatment to surgical intervention.

Adult↗
PubMed1992

[Biopsy of head and neck lesions with a Biopty biopsy instrument].

Recently, "Biopty-Gun" technique has been introduced as a new biopsy technique specially in urological field. We applied it to obtain histopathological specimens of head and neck lesions. 25 specimens were taken with 18-gauge needle, using ultrasonic guidance in cases where the targets were very close to arteries or very small or cystic lesions. All these 25 specimens could be obtained without any complication such as crushing of tissue and they were all sufficiently clear and high-quality specimens. In 23 of these 25 specimens, exact histopathological diagnosis could be made. "Biopty-Gun" minimizing possible movement of tissue which may often occur with the conventional biopsy technique, permitted obtaining tissue specimens without crushing or damaging cells of tissue to be sampled, and it was concluded to be a highly safe and useful biopsy procedure.

Adolescent↗
PubMed1992

[The effects of protease inhibitor upon the ischemia-reperfusion injury].

The purpose of the study is to investigate the effects of protease inhibitor (Nafamostat mesilate: NM) upon myocardial protection. Hearts were subjected to 20 min working control perfusion followed by 3 min cardioplegic infusion with the St. Thomas Cardioplegic Solution (ST) contained various concentrations of NM, and global ischemia for 33 min at 37 degrees C (Exp. 1) or 150 min at 20 degrees C (Exp. 2). Hearts were then converted to Langendorff reperfusion (the leakage of Creatine Kinase (CK) and Cathepsin B (Cat-B) ware measured) and 20 min working reperfusion. Various concentrations of NM added during Langendorff reperfusion (Exp. 3). During working perfusion cardiac functions (aortic flow (AoF), coronary flow (CoF), heart rate (HR), aortic pressure (AoP)) were measured, and expressed as the percent recovery of pre-ischemic control value. Post-ischemic recovery of AoF (%AoF) showed the bell-shaped dose-response curve, and the optimal dose was 3 microM (Exp. 1) and 10 microM (Exp. 2) respectively. There was a significant (p < 0.05) increase of %AoF in optimal dose compared with that in controls (64.2 +/- 1.2% vs 52.3 +/- 2.5% in Exp. 1, 68.9 +/- 3.1% vs 54.1 +/- 1.4% in Exp. 2). These increase of functional recovery reflected in the values for CK and Cat-B leakage. The addition of NM in ST reduced CK and Cat-B leakage significantly in the concentration of 5 microM (in Exp. 1) and 10 microM (in Exp. 2) respectively. But the addition of NM in reperfusate did not reduced CK leakage significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[The effects of potassium concentration in reperfusion solution upon myocardial protection].

The effects of potassium in reperfusion solution (RS) and the influence of sodium on this effect were studied. Experimental time course was as followed: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution followed by global ischemia for 33 or 35 min at 37.5 degrees C, 15 min early Langendorff reperfusion with several different potassium concentration modified with Krebs Henseleit Bicarbonate Buffer (KHBB) containing 145 mM and 110 mM sodium and 5 min late reperfusion with KHBB, followed by 20 min working perfusion. Potassium in RS possessed bell shaped dose response nature with optimal concentration of 10 mM in the condition of 145 mM sodium but 6 m in the condition of 110 mM in terms of percent recovery of aortic flow. Although higher potassium reperfusion produced less Creatine Kinase leakage.

Animals↗
PubMed1992

[Acute relapsing Guillain-Barré syndrome after 5 and 7 years asymptomatic intervals].

A 26-year-old man who recovered from an initial episode of Guillain-Barré syndrome had two relapses after 5 years and then again after 7 years of asymptomatic intervals. The antecedent illnesses, distribution of weakness and clinical courses of each relapse were similar to each other, and each episode reached its peak within 10 days. He received different types of therapy on each time; gammaglobulin and steroid treatment, steroid monotherapy and plasma exchanges. Plasma exchanges were thought to be the most effective. Serum testing by enzyme-linked immunosorbent assay revealed that the patient contained high titer of IgG antibodies against GD1a and GT1b gangliosides and low titer of those against GM1 and GD1b, which were reduced during his clinical improvement.

Adult↗
PubMed1992

[Effects of steroid therapy in IgA nephropathy].

In order to estimate the effects of corticosteroid therapy in IgA nephropathy cases with daily urinary protein excretion of 1.0 g/day or more. 26 patients (8 men and 18 women, aged 32.6 +/- 14.0 years old) were subjected to this study. The results obtained were as follows: Urinary protein excretion after 1 year from the beginning of steroid therapy (1.56 +/- 1.14 g/day) was significantly (p less than 0.05) lower than that at the beginning of the therapy (4.61 +/- 6.01 g/day). In serum creatinine levels, there was no statistically significant difference with them between at the beginning (1.15 +/- 0.48 mg/dl) of steroid therapy and at the time of 1 year after (1.05 +/- 0.34 mg/dl) the therapy. As for the outcome at the end of this study setting (mean follow-up duration: 3.7 +/- 2.6 years), complete remission was attained in 7 cases, improvement in 5 cases, unchanged condition in 11 cases, increased urinary protein excretion in 2 cases and aggravated renal function in 1 case. In clinical findings at the renal biopsy, duration of the disease (3.4 +/- 1.6 months) in complete remission cases before biopsy was significantly (p less than 0.01) shorter than that in unchanged cases (65.0 +/- 40.0 months). In histological findings, rate of global sclerosing glomeruli (2.6 +/- 4.6%) in complete remission cases was significantly (p less than 0.05) lower than that (24.6 +/- 23.1%) in unchanged cases. These results suggest that steroid therapy in IgA nephropathy with persistent proteinuria of 1.0 g/day or more is beneficial, especially in cases that are in early stage of the disease with lower rate of global sclerosing glomeruli.

Adolescent↗
PubMed1992

[The effects of sodium concentration in reperfusion solution upon myocardial protection].

The effects of several sodium concentrations in reperfusion solution (RS) were studied. Experimental time course was as follows: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution followed by global ischemia for 33 min at 37.5 degrees C, 15 min early Langendorff reperfusion with various sodium concentrations modified with Krebs Henseleit Bicarbonate Buffer (KHBB) and 5 min late reperfusion with KHBB, followed by 20 min working perfusion. Percent recoveries of aortic flow and Creatine Kinase leakage showed that 110 mM sodium of RS possessed optimal protective properties with bell shaped dose response characteristics.

Animals↗
PubMed1992

[A case of familial lecithin: cholesterol acyltransferase deficiency].

Lecithin: cholesterol acyltransferase (LCAT) is an enzyme that catalyzes the esterifying reaction of cholesterol in plasma high density lipoprotein (HDL). Deficiency of LCAT is a rare hereditary disease characterized by several clinical symptoms such as proteinuria, corneal opacity, and anemia due to a shortened life span of erythrocytes. In this communication, we report a case of 40 year-old female patient of LCAT deficiency. She visited a hospital for work-up of proteinuria, corneal opacity and anemia. Activity of her serum LCAT was found to be extremely low, and characteristic changes in plasma lipids due to deficiency of LCAT was observed: those were marked decreases in HDL-cholesterol, degree of esterification in serum cholesterol, and apoprotein A-I, A-II, B and C-II levels. The diagnosis of LCAT deficiency was finally made. We studied about histopathological changes in the patient's kidney, and erythrocyte membrane lipid composition and fluidity. Histopathological findings in renal biopsy were follows: a) Light microscopy showed spherical deposits stained with periodic acid-Schiff in mesangial matrix and adjacent capillary loops, and hyaline deposits in arterioles, b) Electron microscopy showed vacuoles in mesangial matrix and along the glomerular basement membranes. In erythrocyte membrane lipids, increase of cholesterol to phospholipid molar ratio was evident, being accompanied by changes in phospholipid fractions: increase of phosphatidylcholine, and decreases of phosphatidylethanolamine, sphingomyelin and lysophosphatidylcholine. In phospholipid acyl chains, increase of C18:2 and decreased of C18:1 were evident in the patient. Erythrocyte membrane fluidity was found to be decreased in the patient in a measurement by pyrene, probably being related to the changes in membrane lipid composition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Biventricular repair for right isomerism associated with transposition of great arteries and common atrioventricular canal].

A 5-years old boy, whose thoracic situs was right isomerism, was diagnosed as transposition of great arteries, common atrioventricular canal (intermediate type), severe tricuspid valve regurgitation, pulmonary valve stenosis, bilateral superior vena cava and left sided inferior vena cava. The preoperative RVEDV was 95% and LVEDV 160%, and LV/RV pressure ratio was 0.54. Atrial rerouting using pericardial patch, replacement of tricuspid valve and pulmonary valvotomy were performed. Postoperative course was uneventful. This was a rare case of right isomerism who received biventricular repair.

Child, Preschool↗
PubMed1992

[The effects of osmolarity in reperfusion solution upon myocardial protection].

The effects of several different osmolarity in reperfusion solution were studied. Experimental time course was as follows: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution (STS) followed by global ischemia for 33 min at 37.5 degrees C, 15 min early Langendorff reperfusion with different osmolarity by adding sucrose and 5 min late reperfusion with Krebs Henseleit bicarbonate buffer, followed by 20 min working perfusion. Percent recoveries of aortic flow showed that 290 mOsm/L in reperfusion solution possessed optimal protective properties with bell shaped dose response characteristics.

Animals↗
PubMed1991

Lithium reduces ocular dominance plasticity in kitten visual cortex.

Activity-dependent processes within the visual pathway play a crucial role in the expression of ocular dominance plasticity in immature visual cortex. The necessity of non-retinal, modulatory afferents to the regulation of ocular dominance plasticity has been recognized. Among a few chemically defined signaling systems, the noradrenaline-activated beta-adrenoreceptors seem to have a prime role in this matter. The involvement of acetylcholine afferents was also proven. We looked for plausible molecular mechanisms which integrate the contribution of the two neuromodulator systems to ocular dominance plasticity. At the first step, based on the rich literature on psychotropic action of lithium and the recent advancement in understanding of its molecular mechanisms, we physiologically studied visual cortex of kittens which had been repeatedly injected with the lithium solution intraperitoneally or the cortex directly infused with it. We found (1) that ocular dominance plasticity was significantly reduced in lithium-injected kittens, (2) that the decrease was directly correlated with plasma concentrations of lithium (i.e. the higher the lithium concentration, the lower the plasticity), and (3) that the comparable decrease in the plasticity was obtained from kitten visual cortex which had been directly infused with the lithium solution. The present results suggest that lithium-sensitive processes, through most likely reduced production of second messengers, underlie the regulation of ocular dominance plasticity.

Animals↗