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Biomedical subjects

H Takada

Publications and source records attributed to H Takada.

At least 19 recordsLinked to original sources
PubMed1992

Novel 5-HT3 antagonists. Isoquinolinones and 3-aryl-2-pyridones.

Synthesis and pharmacological evaluation of a series of 1,2-dihydro-1-[(5-methyl-1-imidazol-4-yl)methyl]-2-oxopyridine 5-HT3 antagonists are described. The key pharmacophoric elements were defined as a basic nitrogen, a linking group capable of hydrogen bonding interactions, and an aromatic moiety. 1,2-Dihydro-2-oxopyridine moiety could be a good linking group because of its nicely planar structure. The steric limitations of the aromatic moiety were investigated by X-ray analysis and computer analysis and shown to be optimal when the aromatic moiety was constrained within an arched planar system, which could be successfully replaced by 3-(2-thienyl)-2-oxopyridine function or 6-amino-7-chloro-1-isoquinolinone function without any loss of the activity. Among the synthesized compounds, 42 showed the most potent activity in the inhibition of Bezold-Jarisch reflex in rats. Compounds 44a and 64 were orally active in the protection against cisplatin-induced emesis in dogs or ferrets. Structure-activity relationships are discussed.

Animals↗
PubMed1992

Endocrine cells and prognosis in patients with colorectal carcinoma.

Using chromogranin (CG) immunohistochemical staining, the prognostic significance of endocrine differentiation was investigated in 212 patients with primary colorectal adenocarcinoma (including 6 patients with mucosal carcinoma). CG-immunoreactive cells were found to be an integral component of the tumor in 67 of 206 patients (32.5%, excluding mucosal carcinoma). The intracellular localization of CG in the CG-immunoreactive cells in cancer tissue was completely different from that in the normal endocrine cells of the large bowel. In addition, morphologic changes such as nuclear hyperchromasia and pleomorphism also indicated that the CG-immunoreactive cells in the cancer tissue were malignant. The tumors were divided into three groups based on the frequency of CG-immunoreactive cells: Group I (n = 139), negative; Group II (n = 38), less than 1 positive cell/mm2; and Group III (n = 29), more than 1 positive cell/mm2. No correlation was observed between CG-immunoreactivity (CG-IR) and tumor location, grade, depth of invasion, or stage, regardless of lymph node involvement. However, patients with numerous endocrine tumor cells (Group III) had a significantly worse prognosis compared with patients without endocrine cells (Group I) (multivariate Cox's model, P less than 0.01). Similar findings were observed in patients with node-negative tumor (multivariate Cox's model, P less than 0.05). These results indicated that the neuroendocrine differentiation is an independent prognostic factor and that CG-immunohistochemistry is useful for detecting a subgroup with a worse prognosis among patients with colorectal cancer.

Biomarkers, Tumor↗
PubMed1992

Generation of chemotactic factor by hepatocytes isolated from chronically ethanol-fed rats.

In an attempt to clarify a mechanism of polymorphonuclear cell and/or macrophage infiltration in alcoholic liver disease, we investigated a novel chemotactic and activating factor generated by rat hepatocytes isolated from the chronically ethanol-fed rats. Hepatocytes and hepatic macrophages were isolated from rat liver by perfusion and digestion with collagenase and subsequently by differential centrifugation on a metrizamide gradient. Rat polymorphonuclear cells were prepared from blood by the dextran sedimentation and Hypaque-Ficoll technique. Chemotactic activity was measured as migration of polymorphonuclear cells or hepatic macrophages using a chemotactic chamber. When hepatocytes isolated from the ethanol-fed rats were cultured in vitro, chemotactic activity for rat polymorphonuclear cells and hepatic macrophages was demonstrated in the culture supernatant. Inhibitors of transcription and protein synthesis reduced generation of chemotactic factor from these hepatocytes. Chemotactic activity of the conditioned medium was reduced after trypsin (0.25%, 37 degrees C, 30 min) or heat (56 degrees C, 30 min) treatment. The chemotactic activity was eluted at molecular weights of 20-25 kDa and 40-45 kDa following Sephadex G-150 chromatography. Superoxide anion production by polymorphonuclear cells and hepatic macrophages under the stimulation of phorbolmyristate acetate was enhanced in the presence of this chemotactic factor. This chemotactic factor may contribute to the pathogenesis of alcoholic liver disease.

Animals↗
PubMed1992

Absence of colorectal cancer metastasis to the cirrhotic liver.

Hepatic metastasis of colorectal cancer was found in 40 (16%) of 250 patients with colorectal cancer treated in our department during the past 5 years. Liver cirrhosis was not found among the 40 patients with metastases (16%) but was present in 46 (21.9%) of the 210 nonmetastatic patients, with a significant difference between the two groups (p less than 0.001). The rate of patients who were positive for hepatitis B surface antibody was 10% in the metastatic group and 34.3% in the nonmetastatic group, with a significant difference (p less than 0.01). These findings suggest that colorectal cancer does not metastasize to the injured liver, especially the cirrhotic liver.

Colorectal Neoplasms↗
PubMed1992

Age-related decline of cerebral oxygen metabolism in normal population detected with positron emission tomography.

Using positron emission tomography (PET), cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were measured in 32 healthy volunteers aged from 27 to 67 years. In bilateral putamen, left supratemporal, left infrafrontal and left parietal cortices, CMRO2 showed a significant decline during aging. The age-related decline of CBF was seen only at the left superior temporal cortex. The mean CMRO2 was significantly lower in the elder group (over 51 years old) than in the younger group (under 50 years old), whereas no significant difference in mean CBF between the two groups. The poor correlation of CBF to the age could be explained partly by the fact that CBF is easily influenced by the physiological, psychological and/or environmental factors. The age-related changes of CMRO2 were more marked in the association cortices of the left hemisphere than in that of the right hemisphere.

Adult↗
PubMed1992

Inhibition of 7,12-dimethylbenz[a]anthracene-induced lipid peroxidation and mammary tumor development in rats by vitamin E in conjunction with selenium.

The effects of combined dietary vitamin E supplementation and a relatively low increase in selenium levels on 7,12-dimethylbenz[a]anthracene (DMBA) induction of lipid peroxidation in the short term and development of mammary tumors in the long term were investigated in female Sprague-Dawley rats. Control animals were fed the basal diet (20 mg/kg vitamin E and 0.6 mg/kg selenium) throughout the experiment. Three other groups received a high vitamin E diet (235 mg/kg vitamin E and 0.6 mg/kg selenium) at different times, the first two from three weeks after DMBA treatment and the other throughout the experiment. When the vitamin E diet with selenium supplementation was applied until three weeks after DMBA or until the termination of the experiment, tumor yields (tumors per rat) were significantly inhibited compared with the control group. On the other hand, delaying the supplementation of vitamin E until three weeks postcarcinogen produced no prophylactic effect. The elevation of lipid peroxidation levels observed immediately after DMBA administration was also significantly inhibited in both mammary fat pads and livers of animals in the high vitamin E group. It was therefore concluded that the inhibitory effect of vitamin E in combination with selenium on tumorigenesis might be causally related to reduction of carcinogen treatment associated with lipid peroxidation, the latter presumably playing an important role in DMBA-induced mammary carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1992

Lipopolysaccharides of Bacteroides intermedius (Prevotella intermedia) and Bacteroides (Porphyromonas) gingivalis induce interleukin-8 gene expression in human gingival fibroblast cultures.

Lipopolysaccharides (LPS) prepared from Bacteroides intermedius (Prevotella intermedia) and Bacteroides (Porphyromonas) gingivalis by hot phenol-water extraction induced interleukin-8 (IL-8) mRNA in normal human gingival fibroblast cultures, as demonstrated by Northern (RNA) blot analysis. IL-8 mRNA levels began to increase after a 2-h exposure, reached a maximum after 12 h, and then dropped to the unstimulated level at 48 h. IL-8 mRNA levels were also enhanced in a dose-dependent manner. By contrast, LPS specimens from various Salmonella species with S and R chemotypes and bacterial [corrected] and synthetic lipid A preparations did not increase IL-8 mRNA levels in fibroblasts. Although recombinant human IL-1 alpha induced IL-8 mRNA expression in fibroblast cultures, an antiserum to recombinant human IL-1 alpha did not decrease the IL-8 mRNA accumulation induced by B. intermedius LPS. Fibroblasts primed with natural human gamma interferon (IFN-gamma) expressed higher IL-8 mRNA levels upon stimulation with B. intermedius LPS, but not with Salmonella LPS, compared with nontreated cells. Natural human IFN-beta exhibited a similar priming effect on the fibroblasts, and antiserum to IFN-beta added to the cultures together with B. intermedius LPS decreased the IL-8 mRNA levels. Therefore, endogenous IFN-beta enhanced IL-8 mRNA production in response to B. intermedius LPS in fibroblasts.

Bacteroides↗
PubMed1992

Mechanism of accumulation of macrophages in galactosamine-induced liver injury: effect of lipoxygenase inhibitors on chemotaxis of spleen cells.

In an attempt to clarify a mechanism of macrophage infiltration in galactosamine-induced hepatic injury, we investigated chemotactic factor(s) generated by murine hepatocytes exposed to galactosamine. Hepatocytes, isolated from murine liver by perfusion and digestion with collagenase, were incubated with galactosamine. Conditioned medium was collected 24 h later and chemotaxis of murine spleen cells was measured by stimulation of the conditioned medium using a modified Boyden chamber. Chemotactic activity was demonstrated in the conditioned medium of hepatocytes exposed to more than 3 mM galactosamine. Chemotactic activity of the conditioned medium was not reduced after freeze-thawing, and found to be dialyzable (molecular weight < 12,000). Trypsin (0.25%, 37 degrees C, 30 min) or heat (56 degrees C, 30 min) treatment reduced chemotactic activity of the conditioned medium. Furthermore, chemotaxis of spleen cells was decreased in the presence of lipoxygenase inhibitors (azelastine, ketotifen). These results suggest that accumulation of macrophages in the liver could be mediated by chemotactic factor produced by the galactosamine-treated hepatocytes, and that this mechanism may contribute to the pathogenesis of hepatic injury induced by galactosamine.

Animals↗
PubMed1992

Predominant activation and expansion of V gamma 9-bearing gamma delta T cells in vivo as well as in vitro in Salmonella infection.

Gamma delta T cell receptor-positive cells (gamma delta T cells) have recently been implicated to play a role in the protection against infectious pathogens. Serial studies on gamma delta T cells in 14 patients with salmonella infection have revealed that the proportions of gamma delta T cells (mean +/- SD: 17.9 +/- 13.2%) in salmonella infection were significantly increased (P less than 0.01) compared with 35 normal controls (5.0 +/- 2.6%) and 13 patients with other bacterial infections (4.0 +/- 1.4%). Expansion of gamma delta T cells was more prominent in the systemic form (28.9 +/- 10.8%) than in the gastroenteritis form (10.5 +/- 7.9%) of salmonella infection (P less than 0.01). Most in vivo-expanded gamma delta T cells expressed V gamma 9 gene product. Increased activated (HLA-DR+) T cells were observed in all the six patients with the systemic form and four of the seven with gastroenteritis form. Especially in the six with systemic form, gamma delta T cell activation was significantly higher than alpha beta T cell activation at the early stage of illness (P less than 0.01). When peripheral blood lymphocytes from normal individuals were cultured with live salmonella, gamma delta T cells were preferentially activated and expanded and most of them expressed V gamma 9. Purified gamma delta T cells also responded to live salmonella in vitro. The present study suggests that human gamma delta T cells play a role in the protection against salmonella infection in vivo.

Adolescent↗
PubMed1992

[High-dose intravenous immunoglobulin treatment in chronic inflammatory demyelinating polyneuropathy].

We treated two patients with chronic inflammatory demyelinating polyneuropathy (CIDP) with high-dose intravenous immunoglobulin (HIG). The patients received 400 mg/kg of immunoglobulin a day for five days. One patient, who had failed to respond to prednisolone before, was treated with HIG, 18 months after the onset. His motor symptoms resolved immediately after the commencement of HIG. Electrophysiologically, the compound muscle action potentials increased in amplitude in all nerves examined and F wave reappeared in the left median nerve. The electrophysiological changes were compatible with improvement of conduction blocks. This patient had headache and exanthema during the HIG therapy, but they settled after cessation of the infusion. The other patient was administered HIG as an initial treatment, four months after the onset. HIG was of no effect in this case, but he showed remarkable recovery during the following prednisolone therapy. Although corticosteroid therapy is the first choice for CIDP, there are CIDP patients who do not respond to steroid or can not complete the steroid therapy because of adverse effects. HIG is an expectative and recommendable treatment for the steroid resistant CIDP patients.

Adolescent↗
PubMed1992

[Short-duration bladder instillation therapy with pirarubicin for superficial bladder tumor based on pharmacodynamic study].

From our experimental study, an instillation of THP for 5 minutes was attempted in 23 patients with superficial bladder tumors. THP (30 mg dissolved in 50 ml of distilled water) was instilled into the bladder 6 times every 48 hours. Of 23 patients, 9 (39%) showed complete disappearance of the bladder tumors, while partial disappearance (more than 50% tumor reduction) was observed in 3 cases (13%). Therefore the overall response rate was 52%. Neither urinary frequency nor hematuria was observed in all the cases, while painful urination was observed in 3 cases (13%). This newly designed bladder instillation therapy was effective against superficial bladder tumors with low incidence of local side effects.

Administration, Intravesical↗
PubMed1992

[A workshop on the high risk group and the preventive oncology of renal cell carcinoma].

A workshop on the high risk group and the preventive oncology of renal cell carcinoma was held in Kyoto on September 7, 1990. The following subjects were presented: 1. Cohort study of renal cell carcinoma (Dr. Hirayama). 2. Pathoepidemiological study on the background of occurrence of renal cell carcinoma (Dr. Aoki). 3. Case-control study on renal cell carcinoma (Dr. Watanabe). 4. Geographic distribution of renal cell carcinoma in Japan (Dr. Minowa). 5. Pathological findings of small renal cell carcinoma (Prof. Yatani). 6. Pathoepidemiological study on occurrence of renal cell carcinoma (Dr. Tsuchihashi). 7. Clinical evaluation of small renal cell carcinoma (Dr. Masuda). 8. Clinical (biological) characteristics of renal cell carcinoma (Dr. Satomi). 9. Mass screening program for renal cell carcinoma on private urological clinic (Dr. Mishina). 10. Early stage detection of renal cell carcinoma (Dr. Ohe). 11. A review on the literature of epidemiology for renal cell carcinoma (Dr. Nakagawa). Possible risk factors reported for renal cell carcinoma were as follows: 1) Work in petroleum-related and dry-cleaning industries were positive risk. A predominant lifetime occupation as a professional was negative risk. 2) Milk or coffee consumption and use of artificial sweeteners were positive. Drinking of alcohol was negative. 3) Obesity was positive. 4) Personal history of cancer was positive. 5) Cigarette smoking was positive. 6) Exposure to radiation or hydrocarbon was positive. 7) Use of estrogen, diuretic and pain relievers was positive. 8) History of myocardial infarction, hypertension and diabetes mellitus was positive.

Carcinoma, Renal Cell↗
PubMed1992

[A case of chronic toluene intoxication with abnormal MRI findings: abnormal intensity areas in cerebral white matter, basal ganglia, internal capsule, brain stem and middle cerebellar peduncle].

We reported a case of 21 years old man of chronic toluene intoxication with abnormal intensity areas on MRI in cerebral white matter, basal ganglia, internal capsule (especially posterior limb), brain stem and middle cerebellar peduncle. The patient developed various neurological abnormalities such as blurred vision, ataxic speech, gaze evoked horizontal nystagmus, bilateral pyramidal tract sign and limb ataxia after 8 years sniffing of thinner (mainly toluene). MRI examination revealed diffuse high intensity areas in cerebral white matter on T1 weighted image. On T2 weighted image, high intensity areas of deep cerebral white matter, internal capsule (especially posterior limb), cerebral peduncle, ventral pons and middle cerebellar peduncle were noted. Basal ganglia (caudate nucleus, lenticular nucleus and thalamus) were displayed as low intensity area on T2 weighted image. These high intensity areas of internal capsule, brain stem and middle cerebellar peduncle on T2 weighted image would be significant for understanding pyramidal tract sign and cerebellar sign of this case. On the basis of neuropathological descriptions of chronic toluene intoxication, these high intensity areas of T2 weighted image were presumed to be demyelinating lesions of the central nervous system.

Adult↗
PubMed1991

Immunohistochemical analysis of plasminogen activator expression in human colorectal carcinomas: correlation with CEA distribution and tumor cell kinetics.

Fifty cases of colorectal adenocarcinoma were immunohistochemically examined for the relationship between distribution of plasminogen activators (PAs) and the degree of differentiation of cancer cells as reflected by carcinoembryonic antigen (CEA) expression as well as tumor cell kinetics. The A chain of urokinase-type PA (u-PA-A) was mainly observed in the apical portions of highly differentiated cancer cells. Increased expression and change in localization to the cytoplasm were found with progressive dedifferentiation. The numbers of DNA polymerase alpha (pol. alpha) positive cancer cells also increased in line with u-PA-A expression. The B chain of u-PA (u-PA-B), and the A and B chains of tissue-type PA (t-PA-A and -B) did not show similar alteration. The present findings suggest that the distribution of u-PA-A in colorectal carcinoma tissues, the degree of tumor differentiation, and the proliferation kinetics of cancer cells are closely related.

Adenocarcinoma↗
PubMed1991

Physiologic and anatomic assessment of patients with rectocele.

Clinical, physiologic, and anatomic assessments were carried out in 22 female patients with symptomatic rectocele (Group A), 15 patients with asymptomatic rectocele (Group B), and 14 subjects having no rectocele (Group C). Resting and pressure, rectal pressure, rectal compliance, anorectal inhibitory reflex, and rectal sensation did not differ among the groups. Proctography revealed that the lengths of the rectocele during attempted defecation in groups A (1.6 [1.0-3.5] cm) (median and range) and B (1.6 [1.0-3.0] cm) were significantly greater than that in Group C (0.4 [0.1-0.9] cm) (P less than 0.001 in both groups). Median pelvic floor descent at rest in Groups A (4.3 [1.6-7.5] cm) (median and range) and B (4.3 [1.3-6.9] cm) were significantly greater than that in Group C (2.5 [1.2-5.0] cm) (P less than 0.001 and P less than 0.02, respectively). These results indicate that rectocele is not associated with any physiologic change apart from a significant increase of pelvic floor descent.

Adult↗