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Biomedical subjects

M Onishi

Publications and source records attributed to M Onishi.

At least 19 recordsLinked to original sources
PubMed1995

Efficient screening of retroviral cDNA expression libraries.

Expression cloning of cDNAs was first described a decade ago and was based on transient expression of cDNA libraries in COS cells. In contrast to transient transfection of plasmids, retroviral gene transfer delivers genes stably into a wide range of target cells. We utilize a simple packaging system for production of high-titer retrovirus stock from cDNA libraries to establish a cDNA expression cloning system. In two model experiments, murine interleukin (IL)-3-dependent Ba/F3 cells were infected with libraries of retrovirally expressed cDNA derived from human T-cell mRNA or human IL-3-dependent TF-1 cell line mRNA. These infected Ba/F3 cells were selected for the expression of CD2 by flow cytometry or for the alpha subunit of the human IL-3 receptor (hIL-3R alpha) by factor-dependent growth. CD2 (frequency, 1 in 10(4)) and hIL-3R alpha (frequency, 1 in 1.5 x 10(5)) cDNAs were readily detected in small-scale experiments, indicating this retroviral expression cloning system is efficient enough to clone low-abundance cDNAs by their expression or function.

3T3 Cells↗
PubMed1995

Analysis of antitumor properties of effector cells stimulated with a cell wall preparation (WPG) of Bifidobacterium infantis.

Intestinal Bifidobacterium species are thought to be beneficial in animal and human intestines. We studied the mechanisms of Bifidobacteria in antitumor activity using a cell wall preparation (WPG) of B. infantis (Cancer Res., 45, 1300, (1985)). WPG enhanced the in vitro antitumor activities of mouse peritoneal exudate cells elicited with proteose-peptone (P-PEC) and thioglycollate broth (TG-PEC), determined by cytostatic ([3H]thymidine uptake inhibition) and cytolytic ([3H]uridine release) assays. Tumor necrosis factor-alpha (TNF-alpha) and reactive nitrogen intermediates (RNI) play a role in such augmented cytotoxicity, because anti-TNF-alpha antibody almost completely blocked the increased cytolytic activity of P-PEC in the presence of WPG. Moreover, WPG induced RNI in the supernatant of TG-PEC in a dose-dependent manner. The mRNA expression of several cytokines (IL-1 beta, IL-6, IL-10, IFN-alpha and TNF-alpha) was induced in BALB/c mouse peritoneal cells 3 h after an intraperitoneal injection of WPG (3 h WPG-PEC). However, this expression disappeared from 24 h WPG-PEC, except for that of IFN-alpha. IFN-gamma was not induced. Kinetic studies of the tumor neutralizing activities of the WPG-PECs by means of the in vivo Winn assay revealed that the activity emerged at 1.5 h, became maximal at 3 h and disappeared at 24h. These results indicated that Bifidobacterial WPG is a Biological Response Modifier (BRM) with characteristics similar to those of other bacterial BRMs.

Animals↗
PubMed1994

Progression and regression of atherosclerotic findings in the descending thoracic aorta detected by enhanced computed tomography.

Reports evaluating the progression and regression of atherosclerosis by non-invasive procedure are still limited. We investigated the progression and regression of atherosclerotic intimal thickening of the descending thoracic aorta non-invasively measured by enhanced computed tomography in 83 patients (average age 51.0 years) at the beginning and end of a 2.5 year period. The patients were not taking anti-hypertensive, lipid-lowering or hypoglycemic drugs and therefore we consider them as a natural history cohort. At entry, the extent of aortic intimal thickening was 35.2% of the circumference of the cross-section of the wall, which increased to 39.7% after 2.5 years. Spontaneous progression was associated directly with age, elevated levels of total cholesterol, LDL-cholesterol, LDL/HDL cholesterol ratio, diastolic blood pressure, and inversely to HDL-cholesterol. There was little correlation with triglycerides, systolic blood pressure, fasting glucose or body mass index. In 65 of the patients, aortic atherosclerosis progressed, while in 9 patients it remained unchanged, and in a further 9 it regressed. The levels of lipid variables, apart from HDL-cholesterol, and diastolic blood pressure in the patients with spontaneous progression were significantly higher than in the unchanged and spontaneous regression. Thus, this study verified the natural history of aortic atherosclerosis non-invasively measured by enhanced CT.

Adult↗
PubMed1994

[Single dose toxicity study of lactitol (NS-4) in dogs].

Male beagle dogs were orally given lactitol, a hepatic encephalopathy drug, in a single dose of 7.5, 15.0 or 30.0 g/kg. Vomiting was seen within 30 minutes after dosing in all treated groups. Diarrhea was observed 3 or 5 hours after dosing in the 15.0 and 30.0 g/kg dose groups. There were no drug related effects on survival, food and water consumption, body weight gain or tissues and organs.

Administration, Oral↗
PubMed1994

[52-week oral toxicity study of lactitol (NS-4) in dogs followed by 9-week recovery test].

Five male and 5 female beagle dogs were orally given lactitol, a hepatic encephalopathy drug, for 52 weeks at doses of 0, 0.25, 1.25 or 6.25 g/kg/day. A 9 week recovery test was conducted after the discontinuation of the drug treatment. Soft stool, diarrhea, and vomiting were seen in the 1.25 and 6.25 g/kg groups. In the 6.25 g/kg group, bloody stool and increased water consumption were also observed. Urinalysis showed larger amount of the urine volume in the 6.25 g/kg group. The cecum weight of this group was increased without any morphological changes. There were no drug related effects on survival, body weight gain and food consumption. Electrocardiographic, ophthalmoscopic, hematologic and biochemical examinations failed to show any abnormalities related to the drug treatment. The above mentioned changes were satisfactorily reversible. Based on the results obtained, the NOAEL of this study was suggested to be 0.25 g/kg/day.

Administration, Oral↗
PubMed1992

Evaluation of morphological changes of the atherosclerotic aorta by enhanced computed tomography.

Enhanced and non-enhanced computed tomography (CT) were performed in 405 subjects (222 men; 183 women; mean age 57 years). Intimal atherosclerotic changes of the aorta were quantified by enhanced CT, revealing the atheromatous intima to be projecting and thick-walled, while non-enhanced CT demonstrated aortic calcification. We measured the degree of aortic intimal changes at various segments of the aorta. In 224 cases, CT was performed from the aortic root to the bifurcation of the abdominal aorta. Intimal changes were found predominantly at the aortic arch, the middle descending thoracic and the infrarenal abdominal aorta. As for the intimal changes, aortic calcification and aortic pulse wave velocity were significant atherosclerotic characteristics. The aortic diameter did not show a significant association with intimal change. Among the various atherosclerotic risk factors, intimal change was significantly associated with age, systolic blood pressure, serum total cholesterol and diabetes mellitus, whereas gender, diastolic blood pressure, relative weight and cigarette use were not significantly related. For coronary artery disease and arteriosclerosis obliterans, aortic intimal changes constituted a significant atherosclerotic feature. In cerebrovascular disease, however, aortic intimal change did not play a significant role.

Adolescent↗
PubMed1992

Primary mediastinal diffuse large cell lymphoma initially presented with pericardial infiltration.

A 33-year-old Japanese woman visited our hospital with progressive dyspnea. A chest roentgenogram and a chest computed tomogram revealed a mediastinal tumor and pericardial effusion. Ultrasound cardiography revealed the existence of cardiac tamponade. She was successfully treated with emergency pericardial drainage, thoracocentesis and chemotherapy. The histological diagnosis of diffuse large B cell lymphoma was established with the tumor specimen obtained by transcutaneous fine needle aspiration biopsy and through immunohistochemical analysis. This is a rare case of primary mediastinal diffuse large cell lymphoma with initial presentation of a symptom related to pericardial effusion.

Adult↗
PubMed1992

[A case of traumatic right diaphragmatic hernia diagnosed by pleurography].

The diagnosis of traumatic diaphragmatic hernia is relatively easy on the left side, but is often difficult on the right, partly because the herniated organ is usually the liver. Recently, we experienced a relatively rare case of traumatic right diaphragmatic hernia and found that pleurography was useful for its diagnosis. This case is reported here together with some discussion of the literature.

Accidents, Traffic↗
PubMed1991

MK-801 fails to modify the effect of methamphetamine on dopamine release in the rat striatum.

The effect of MK-801 at a dose of 0.5 mg kg-1, i.p., on methamphetamine-induced (MAP; 4 mg kg-1, i.p.) dopamine (DA) release was examined in the striatum of freely moving rats using an in-vivo microdialysis method. Combined treatment of MK-801 with MAP did not modify the MAP-induced increase in extracellular DA levels or the decrease in 3,4-dihydroxyphenylacetic acid levels. These findings suggest that MK-801 fails to modify the acute effect of MAP on DA release in the striatum. The blocking effect of MK-801 on the development of MAP-induced behavioral sensitization is unlikely to be mediated by DA neurons.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1989

Potentiality of protamine sulfate as mutagen.

The mutagenicity of protamine sulfate has been clarified based on chromosomal aberration of cultured chinese hamster lung cells (cell line) in direct and metabolic activation methods and microbial mutagenesis (Ames test). In chromosomal aberration test, protamine sulfate caused cytotoxicity in the high doses (2500 and 5000 micrograms/ml) in the presence of rat liver homogenates (S-9). But very negligible or no cytotoxicity occurred in direct method at high dose (5000 micrograms/ml). Structural aberration of chromosome was not occurred in either of the methods. In microbial mutagenesis study, protamine sulfate did not show any cytotoxicity to microbes up to the dose of 5000 micrograms per plate. Furthermore, it did not have any effect in microbes like mutagens or like some toxic agent. The study reveals that protamine sulfate is not mutagen.

Animals↗
PubMed1989

[Systolic time intervals in mitral valve prolapse syndrome].

Systolic time intervals (STI) were measured in 135 patients with mitral valve prolapse syndrome (MVP). These patients were categorized as Group II (no or trivial mitral regurgitation) and Group III (moderate or severe regurgitation). The controls consisted of 120 normal subjects (Group I). The Group II patients tended to have increased ETc and shortened PEP. The Group III patients tended to have prolonged Q-I and decreased QIIc and ETc, reflecting mitral regurgitation. It was suggested that autonomic nervous system, especially sympathetic nerve, may play a role in changes of STI of the Group II patients.

Adolescent↗
PubMed1989

[Anticonvulsant effects of bifemelane hydrochloride on kindled seizures from the amygdala and hippocampus in rats].

The anticonvulsant affects of bifemelane hydrochloride, a novel therapeutic drug for cerebrovascular dementia, were investigated in the kindling model of epilepsy in rats. The results obtained were as follows. (i) Both the seizure stage and afterdischarge duration of kindled seizures from the amygdala and hippocampus were significantly suppressed following systemic injection of bifemelane hydrochloride (5-30 mg/kg) in a dose-dependent manner. (ii) The efficacy of anticonvulsant action on kindled seizures from the hippocampus was more potent than from the amygdala. (iii) The maximum anticonvulsant effects were observed between 1 and 4 h after injection, and this time course was very similar to that of the previously reported increasing effects of bifemelane hydrochloride on noradrenaline levels in the rat brain. Thus, it is suggested that these anticonvulsant effects in kindling may be mediated by central noradrenergic systems. These results indicate that bifemelane hydrochloride has a potent anticonvulsant action on kindled seizures and may be useful for dementia patients with epilepsy or other seizure disorders.

Amygdala↗
PubMed1987

[Chronic toxicity and recovery tests of rokitamycin in beagle dogs].

Six-month oral chronic toxicity study and two-month recovery tests on rokitamycin (TMS-19-Q) were performed in Beagle dogs at daily doses of 90, 180 and 360 mg/kg. The results were summarized as follows: No death occurred to any animals in these experiments. In higher dosage groups (180 and 360 mg/kg), vomiting, salivation and reduction of body weight gain with decrease in food intake were observed. Body temperature and pulse rate were normal, and ECG, sperm and vaginal smear tests, urinalysis, blood and biochemical examinations also revealed normal values. No marked changes in organ weights, necropsy, histopathological and electron microscopic observations were detected.

Administration, Oral↗