Search PubMed⌕ Search

Biomedical subjects

H Tabata

Publications and source records attributed to H Tabata.

At least 55 records · Page 3Linked to original sources
PubMed1997

[A case of colon cancer with local recurrence successfully treated by systemic and local intra-arterial chemotherapy using a combination of 5-fluorouracil, interferon-alpha 2A, leucovorin and carboplatin].

A 59-year-old man with colon cancer was diagnosed as having a local recurrence of the disease, forming a huge intra pelvic tumor, accompanied by pulmonary metastasis 16 months after hemicolectomy. He received alternate systemic and local chemotherapy consisting respectively of a 5-day course of continuous infusion of 5-FU 600 mg/m2/day, bolus injection of leucovorin (LV) 20 mg/m2/day, intramuscular injection of interferon (IFN)-alpha 2a 6 x 10(6) IU/day, and intra-arterial administration of 5-FU, LV and carboplatin using reservoir catheter through pudendal artery, each repeated every 3 weeks. After 6 systemic and 8 local treatments, metastatic lesions disappeared and the intra-pelvic tumor shrunk by 62%, indicating a partial response. The patient then underwent dissection of the intra-pelvic tumor. Pathological examination indicated a curative resection. Alternate systemic and local intra arterial chemotherapy using a combination of 5-FU, LV, IFN and and carboplatin is highly promising for metastatic colorectal cancer with local recurrence.

Adenocarcinoma↗
PubMed1996

Methyl jasmonate-induced overproduction of paclitaxel and baccatin III in Taxus cell suspension cultures.

Taxus cell culture may be an alternative source of paclitaxel and related taxane production. Significantly increased amounts of paclitaxel and baccatin III were observed in cultured cells of Taxus species after exposure to methyl jasmonate. Among the three species of Taxus tested, Taxus media showed the highest paclitaxel content while Taxus baccata showed the highest baccatin III content when 100 microM of methyl jasmonate was added to the culture media. Furthermore, the activities of methyl jasmonate and related substances for inducing paclitaxel production were compared in cell suspension cultures of T. media. Methyl jasmonate and its free acid showed the strongest promoting activity. Reduction of the keto group at the C-3 position greatly reduced this activity. cis-Jasmone, which does not have a carboxyl group at the C-1 position, had almost no activity. These results suggest that these two regions of methyl jasmonate are important for promoting the production of paclitaxel and related taxanes in Taxus cell cultures.

Acetates↗
PubMed1996

Electron-microscopic study of sclerodermatous chronic graft-versus-host disease.

BACKGROUND: Sclerodermatous chronic graft-versus-host disease (SC-GVHD) resembles systemic scleroderma (SSD) closely, both clinically and histologically. Our purpose was to try to define the morphologic differences of collagen fibers between SC-GVHD and SSD. MATERIALS AND METHODS: Using electron microscopy, we compared the morphology of collagen fibers in a 15-year old girl with SC-GVHD with those of three patients with SSD. RESULTS: In SC-GVHD, sclerosis is located in the superficial dermis and collagen fibers of irregular diameter are seen in the subepidermal area. In SSD, sclerosis is seen in the lower dermis and subcutaneous fatty tissue, and collagen fibers of irregular diameter are located in the deep dermis. Some of the collagen fibers were degenerative in the superficial dermis in SC-GVHD. We observed low-density, round structures in cross sections of collagen fibers. CONCLUSIONS: The difference in initial location and morphologic appearance of collagen fibers may indicate a different pathogenesis in SC-GVHD compared to SSD.

Adolescent↗
PubMed1996

Oncogenicity studies of the new serotonin (5-HT)3-receptor antagonist ramosetron in mice and rats.

Oncogenicity studies of ramosetron ((R)-5-[(1-methyl-3-indolyl)carbonyl]-4,5,6,7-tetrahydro-1H-benzimidazol e hydrochloride, CAS 132907-72-3, YM060), a new compound having serotonin (5-HT)3 receptor antagonist activity, were carried out in male and female mice and rats. Six groups (two control and four treated) of B6C3F1 mice and F344 rats were given YM060, dissolved in distilled water, once daily by oral intubation at doses of 0, 1, 10, 30 and 100 mg/kg/d. Toxicokinetics indicated that sufficient exposure of the animals to the test material was achieved during the oncogenicity studies. Cmax and AUC of YM060 at 100 mg/kg/d were in the range of 3-5 micrograms/ml and 8 micrograms.h/ml in mice, 1-5 micrograms/ml and 7-16 micrograms.h/ml in rats, respectively. The administration of YM060 resulted in a slightly increased mortality rate among female rats treated with 30 or 100 mg/kg/d, particularly during the Weeks 38-87. Body weights of the high-dosed male and female rats during the Weeks 36 to 96 were significantly decreased when compared to controls. An approximately 30% suppression of body weight gain was recorded during Weeks 36-96 for both male and female rats, and 15% suppression of body weight gain was recorded during Weeks 0-104 for male mice. There was no evidence of a treatment-related effect on the incidence of any tumor or tumor type, and there were no non-neoplastic findings considered to be related to the administration of YM060. All microscopic changes seen in mice and rats were of the usual type commonly occurring in untreated aged B6C3F1 mice and F344 rats. In conclusion, there was no evidence of an oncogenic effect of YM060 in mice and rats.

Animals↗
PubMed1996

Two-week oral mucosal irritation study with ramosetron orally disintegrating tablets in Syrian hamsters.

The potential of ramosetron ((R)-5-[(1-methyl-3-indolyl)carbonyl]-4,5,6,7-tetrahydro-1 H-benzimidazole hydrochloride, CAS 132907-72-3, YM060) orally disintegrating tablets to cause irritation to the oral mucosa was assessed in a group of six male and six female Syrian hamsters. Each animal was given one tablet containing 0.1 mg YM060 into the right cheek pouch once daily for 14 consecutive days. A neck collar was fitted for 1 h after each administration to ensure that the tablet was not expelled. A similarly constituted group of hamsters received placebo tablets and acted as a contemporaneous control. Left and right cheek pouches were examined before dosing each day, and on the day following the last treatment. At the end of the treatment period the animals were killed, the cheek pouches excised and examined macroscopically. The cheek pouches of all animals were assessed for histopathological change. There were no signs to indicate systemic or local reactions to treatment in any animal. Macroscopic and microscopic examination of the cheek pouches did not reveal any treatment-related effect. It is concluded that YM060 orally disintegrating tablets are non-irritant to the hamster oral mucosa.

Animals↗
PubMed1995

Angioscopic identification of coronary thrombus in patients with postinfarction angina.

OBJECTIVES: The purpose of this study was to determine the prevalence of intracoronary thrombus and associated anatomic abnormalities in patients with postinfarction angina using coronary angioscopy and angiography. BACKGROUND: Postinfarction angina, previously studied by angiographic methods only, identifies patients at high risk for sudden death, recurrent angina and refractory angina. The recent development of coronary angioscopy, which permits direct observation of a thrombus or atheroma and is especially used for the detection of intraluminal changes, encourages a reexamination of the pathogenesis of postinfarction angina. METHODS: Fifty-one consecutive patients with a diagnosis of acute myocardial infarction underwent cardiac catheterization. Coronary angiography followed immediately by coronary angioscopy was performed in 17 patients with and 34 without postinfarction angina during the same period of time (10.2 +/- 3.7 or 15.7 +/- 5.5 days [mean +/- SD]) after the onset of acute myocardial infarction. RESULTS: The frequency of thrombus, as observed by angioscopy, was significantly higher in patients with than without postinfarction angina (17 of 17 vs. 5 of 34, respectively, p < 0.01). There were no significant differences between groups with respect to degree of stenosis in the infarct-related artery, number of vessels with significant stenosis, presence of collateral flow, type of therapy and risk factors. CONCLUSIONS: Infarct-related artery thrombus is universally present in postinfarction angina and may be the primary pathogenic factor. Angioscopy is much more sensitive than coronary angiography for the detection of coronary thrombus.

Aged↗
PubMed1995

[Angioscopic observation of the ruptured plaque cap in a patient with acute myocardial infarction with particular reference to the mechanism of plaque rupture].

A 45-year-old man was admitted with the diagnosis of acute inferior myocardial infarction. After successful thrombolytic therapy, coronary angiography showed TIMI grade 3 flow with the filling defect and haziness on the infarct-related coronary segment. Repeat coronary angiography and coronary angioscopy were performed on the 28th hospital day. Coronary angiography showed 50% stenosis of the luminal diameter of the right coronary artery. Coronary angioscopy showed a white plaque with ruptured cap which occupied one third of the circumferential coronary artery. The torn ends of the cap were longitudinal, and projected into the lumen during the cardiac cycle. Plaque rupture and thrombus formation are important in the pathogenesis of acute coronary syndromes, although the mechanism of plaque rupture is still controversial. The present angioscopic findings seem to support the concept that circumferential tension or mechanical stretch from part of the coronary artery causes the longitudinal fissure at the weakened site of the plaque cap.

Angioscopy↗
PubMed1995

Acute, subacute and chronic oral toxicity studies of the new serotonin (5-HT)3-receptor antagonist ramosetron in beagle dogs.

The oral toxicity of ramosetron ((R)-5-[(1-methyl-3-indolyl) carbonyl]-4,5,6,7-tetrahydro-1H-benzimidazole hydrochloride, CAS 132907-72-3, YM060), a new compound having serotonin (5-HT)3 receptor antagonist activity was investigated in beagle dogs. To evaluate the acute toxicity, two groups of beagle dogs, each comprised of one male and one female, were given YM060 bulk powder in gelatin capsules at dose of 0, 3 mg/kg or 0, 30 and 60 mg/kg in ascending order in at least 7-day intervals. After the final dose, animals were observed for 2 weeks. No deaths were observed at any dose. At 60 mg/kg, the male exhibited frequent vomiting, salivation and prone position 1-3 h after administration, when the plasma concentration of the unchanged drug reached Cmax or was close to Cmax. The female exhibited no changes except vomiting. No effects on either the male or the female were detected in body weight, food consumption, electrocardiography, hematology, plasma biochemistry or urinalysis. To evaluate the subacute toxicity of YM060, three male and 3 female beagle dogs per group received doses of 0, 1, 3, 10 and 20 mg/kg/d for 13 weeks. YM060 was triturated 10-fold using lactose and filled in gelatin capsules before use. The plasma concentration of unchanged drug increased almost dose-dependently, peaked about 2 h post-dosing and subsequently decreased with time. The plasma concentration-time profile after the final dose at week 13 was not different from that after the initial dose. No treatment-related changes were observed up to 3 mg/kg/d.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1994

A novel assay system for anti-human immunodeficiency virus type 1 (HIV-1) activity using a subclone of a monocytic cell line, U937.

A subclonal cl.1-14 cell was established from a monocytic cell line U937 by a limiting dilution method. The anti-HIV-1 activity of some antiviral compounds was evaluated in HIV-1-infected cl.1-14 cells. The results demonstrated that although AZT was a potent inhibitor of HIV-1 replication in cl.1-14 cells, its 50% effective concentration (EC50) values was 80 times higher than that in HIV-1 infected MT-4 cells; the EC50 of AZT was 0.16 microM and 0.002 microM in cl.1-14 and MT-4 cells, respectively. In contrast, the anti-HIV-1 activity of ddA, ddI and ddC in cl.1-14 cells was comparable to that in MT-4 cells. The antiviral activity of nevirapine, dextran sulfate, curdlan sulfate and T22 did not differ significantly between the cl.1-14 and MT-4 cells. The antiviral activity of several compounds in the HIV-1-infected cl.1-14 cells was similar to that in the HIV-1JR-FL-infected human peripheral macrophages. Our results suggest that cl.1-14 cell cultures are very useful for estimating antiviral activity and more advantageous than the use of peripheral blood macrophages.

Antiviral Agents↗
PubMed1994

Cough variant asthma: a case study with antigen, histamine and methacholine inhalation challenge tests.

This paper presents a 7 year old girl with cough variant asthma, in which house dust challenge test provoked fine crackles on auscultation without any changes of lung function test. Pretreatment with DL-chlorpheniramine maleate for 7 days inhibited the appearance of fine crackles. On histamine inhalation test, fine crackles and rhonchi appeared on auscultation without bronchoconstriction (% fall of one-second forced expiratory volume < 10%). These data suggest that the cause of cough variant asthma is mainly an immunoglobulin E-mediated allergic reaction in the mucus secreting system.

Asthma↗