Search PubMed⌕ Search

Biomedical subjects

S Yasuda

Publications and source records attributed to S Yasuda.

At least 163 records · Page 9Linked to original sources
PubMed1998

Factors influencing physiological FDG uptake in the intestine.

The intestine is a well-known site of physiological 18F-fluorodeoxyglucose (FDG) accumulation in positron emission tomography (PET). To identify factors influencing physiological FDG uptake in the intestine, the intensity of FDG uptake was evaluated in a total of 1,068 healthy adults. Non-attenuation-corrected whole-body PET images were obtained for all subjects and visually evaluated. Subjects were then classified into two groups according to the intensity of intestinal FDG uptake. Sex, age, presence or absence of constipation, and serum glucose, hemoglobin A1c, and free fatty acid levels were compared between the two groups. High intestinal FDG uptake was observed at an overall rate of 11.0%. Sex (female), age, and bowel condition (constipation) were found to affect intestinal FDG uptake. The factors we identified lead to further questions regarding the relationship between intestinal motility and glucose uptake that warrant further study.

Adult↗
PubMed1998

[Immunohistochemical staining of thymidine phosphorylase in primary colorectal carcinoma and metastases].

Thymidine phosphorylase (TdRPase) is an enzyme involved in the pyrimidine metabolism. It was reported that many cancers contained higher levels of TdRPase than normal tissues. And TdRPase has been reported to be identical with the platelet-derived endothelial cell growth factor. To clarify the distribution of TdRPase in primary and metastatic colorectal cancer, we carried out immunohistochemical staining of formalin-fixed specimens. We investigated 35 primary colorectal cancers resected surgically, 27 hepatic metastases and 8 lung metastases from colorectal carcinoma. TdRPase was highly expressed in primary colorectal cancer with lung metastases (100.0%) and surgically resected lung metastases cancer (87.5%). The staining correspondence between primary colorectal cancer and metastases was 19 cases (70.4%) in the liver metastases and 7 cases (87.5%) in the surgically resected lung metastases. The above results suggested that immunohistochemical staining for primary colorectal cancer may provide information about the sensitivity of metastases to the chemotherapy.

Adult↗
PubMed1998

[Collaterals after flow alternation in pelvic arteries: precondition for pelvic reservoir therapy].

To determine the best flow alternation in the internal iliac arteries for regional chemotherapy using a reservoir to treat pelvic malignancies, collateral arteries that arose after arterial flow alternation were evaluated on follow-up pelvic angiographies. Follow-up angiographies were obtained in 11 patients with 21 embolized arteries; six male and five female patients including three with urinary bladder cancer, two with prostate cancer, four with uterine cervical cancer and two with bone metastasis. The interval until follow-up angiography ranged from one to-28 months (mean 8.9 months). Three radiologists interpreted the angiographic results and evaluated collateral vessels. Among 21 embolized arteries, 19 were well occluded, while two were not blocked completely. The two arteries with incomplete embolization did not induce collaterals. Eight internal iliac arteries occluded at the proximal portion enhanced retrogradely via collaterals from the ipsilateral external iliac arteries. Collaterals between the bilateral internal iliac arteries were noted only in four of them. In conclusion, embolization at the proximal point of the internal iliac arteries usually induced collaterals from the ipsilateral external iliac arteries and did not always from collaterals between the bilateral internal iliac arteries, which were necessary for regional chemotherapy. This should be considered when pelvic malignancies are treated with reservoirs.

Adult↗
PubMed1998

[Method of preventing hepatic artery occlusion during continuous intrahepatic arterial infusion chemotherapy of 5-FU].

A randomized clinical trial of combined use of steroids, which have a vascular endothelium-protecting action, was performed to develop a method to prevent hepatic artery occlusion during continuous intrahepatic arterial infusion chemotherapy with 5-FU. The steroid used was dexamethasone palmitate (Limethason), which has a high rate of uptake by endothelial cells. The 24 patients with advanced colorectal cancer were divided into 2 groups randomly and both were treated with 5-FU 250 mg/day by continuous hepatic arterial infusion for three weeks. The weekly dose was 5-FU 7 V (1,750 mg) adjusted to 50 ml with physiological saline in Group A and 5-FU 7 V (1,750 mg) adjusted to 50 ml with Limethason 1 A (4.0 mg of dexamethasone palmitate) in Group B. The reservoir was replaced every week. No changes in the mixture (appearance, pH, granule diameter, dexamethasone palmitate content) were observed up to one week. Hepatic arterial stenosis was observed in 8 cases in Group A (67%), but was not observed in any of the cases in Group B. The above results indicated that Limethason has a preventive effect against hepatic artery occlusion.

Anti-Inflammatory Agents↗
PubMed1998

[Bleomycin, adriamycin, cyclophosphamide, vincristine, deacadron, etoposide (BACOD-E) chemotherapy for the treatment of non-Hodgkin's lymphoma: long-term survival rate and complications].

This study was performed to analyze the effect of Bleomycin, Adriamycin, Cyclophosphamide, Vincristine, Deacadron, Etoposide (BACOD-E) chemotherapy for patients with non-Hodgkin's lymphoma. Seventy patients with non-Hodgkin's lymphoma (stage I: 15, stage II: 23, stage III: 20, and stage IV: 12) were treated at the Department of Radiology, Chiba University Hospital, between 1987 and 1995. The response rates for treatment were CR: 63%, PR: 35%, and PD: 2%. The overall disease-free 5-year survival rate was 54%, and those for each stage were as follows: stage I: 78%, stage II: 55%, stage III: 51%, and stage IV: 28%. There were no significant differences between patients with and without B symptoms, or those with and without elevated LDH levels. Treatment associated deaths occurred in six patients. Two patients died due to side effects of chemotherapy during treatment, and one patient due to leukemia 2 years and 5 months after treatment. One patient died due to radiation pneumonitis, one patient due to heart failure, and one patient due to an unknown reason one month after treatment. This chemotherapy may be useful for patients with advanced disease or unfavorable prognostic factors such as B symptoms or elevated LDH. Moreover, the addition of radiation therapy may prolong survival.

Adolescent↗
PubMed1998

[Running fit and generalized tonic-clonic seizure are differently controlled by different subtype receptors in the brainstem].

Rats neonatally treated with 0.02% propylthiouracil (PTU) through mother's milk showed a high incidence of audiogenic seizures after maturation. These audiogenic seizures were differently modified by MK-801 and NBQX; while intraperitoneal MK-801 equally inhibited running fit (RF) and generalized tonic-clonic seizure (GTCS), NBQX administered into cisterna ambiens significantly inhibited RF but not GTCS. The possible involvement of glutamate receptors in the inferior colliculus was further investigated using naive Sprague-Dawley rats injected with NMDA, AMPA or cyclothiazide, known as an inhibitor of desensitization of AMPA action. All drugs tested successfully induced RF followed by GTCS, resembling audiogenic seizures in PTU-treated rats. However, sound stimulation could augment AMPA-induced, but not NMDA-induced GTCS. Systemic administration with MK-801 potently blocked GTCS induced by AMPA/cyclothiazide, but the same drug failed to block RF after intracisternal injection with AMPA/cyclothiazide. Furthermore, intracisternal administration with NBQX significantly inhibited only RF induced by AMPA/cyclothiazide. The present study suggests that: 1) glutamate receptors in the brainstem, possible in the inferior colliculus, play a crucial role in audiogenic seizures, namely the initiation of RF and propagation into GTCS; and 2) the initiation mechanism is regulated by both NMDA and AMPA receptors, whereas propagation is mainly controlled by NMDA receptors.

Acoustic Stimulation↗
PubMed1998

Colonic adenoma detected by positron emission tomography (PET): a case report.

A 61-year-old asymptomatic woman underwent whole-body positron emission tomography (PET) with 18F-fluorodeoxyglucose and was found to have a lesion in the ascending colon. Further colonic examination was not performed due to her medical condition. One year later, the lesion was demonstrated again by PET. After the second PET study, she underwent colonoscopy, which revealed a pedunculated polyp in the ascending colon. A polypectomy was performed. Histopathological study showed a 1.8-cm adenoma with mild to moderate atypia. The findings in our case suggest that increased glucose metabolism can be depicted by PET in colonic adenoma as well as in primary colonic carcinoma. Although the differentiation between colonic adenoma and carcinoma can not be determined by PET, adenomas are considered to have potential for malignant transformation and thus need to be resected. Therefore, it is noteworthy that PET can be used in the detection of adenomas.

Adenomatous Polyps↗
PubMed1997

Efficient virus transmission from dendritic cells to CD4+ T cells in response to antigen depends on close contact through adhesion molecules.

Monocyte-derived cultured dendritic cells (DCs) are potent antigen-presenting cells (APCs) and are susceptible to HIV-1Lai infection. Compared to the low level of virus production by HIV-1-infected DCs alone, a level of virus two to three orders of magnitude higher was produced by cocultivation of HIV-1-infected DCs with autologous resting CD4+ T cells in the presence of a nominal antigen. In this coculture system, direct contact of HIV-1-infected DCs with T cells was crucial for efficient virus transmission and subsequent virus production. Blocking of the LFA-1/ICAM-1 or LFA-3/CD2 interaction between these cells substantially reduced virus production, without influence or IL-2 production by activated T cells. In contrast, cell-cell transmission of HIV between non-APCs and activated T cells was not blocked by an antibody against LFA-3. Since a low level of virus production by HIV-infected DCs was upregulated by cross-linking of CD40, it was suggested that not only focal adhesion, but also mutual activation of HIV-infected DCs and T cells through adhesion molecules, may potentiate virus transmission and production and that such activation signals to HIV may be distinct from signals responsible for IL-2 production in activated T cells.

Antigen Presentation↗
PubMed1997

Detection of mouse skeletal muscle-specific product, which includes ZF5 zinc fingers and a VP16 acidic domain, by reverse transcriptase PCR.

ZF5, which we have cloned as a repressor on the mouse c-myc promoter, is a zinc finger protein containing Kruppel-type zinc finger and ZiN/POZ domains. In a reverse transcriptase PCR assay using mouse skeletal muscle RNA, we identified a 827 bp PCR product including the zinc finger domain of ZF5 and the acidic domain of VP16. The presence of the VP16 acidic domain induced the reduction of DNA-binding activity of the zinc finger domain. In addition, the inhibitory effect of the VP16 acidic domain was demonstrated on the human immunodeficiency virus (HIV) promoter, but there was no effect on the thymidine kinase (TK) promoter.

Amino Acid Sequence↗
PubMed1997

Radiotherapy for centrally recurrent cervical cancer of the vaginal stump following hysterectomy.

PURPOSE: This study was performed to establish the classification and the treatment modality for recurrent cervical cancer of the vaginal stump after hysterectomy. PATIENTS AND METHODS: Ninety patients with centrally recurrent cervical cancer of the vaginal stump following hysterectomy were treated with high-dose-rate intracavitary brachytherapy with or without external irradiation. The intervals between primary surgery and vaginal recurrences varied from 3 months to 36 years. Tumor size of the vaginal stump was determined by bimanual rectovaginal examination at the time of recurrence and was classified into three groups, i.e., small (no palpable tumor), medium (less than 3 cm), and large (3 cm or more). RESULTS: The 10-year survival rates for all patients were 52%. Survival was greatly influenced by the tumor sizes of the vaginal stump. The 10-year survival rates of patients with small, medium, and large size tumors were 72, 48, and 0%, respectively. All patients with large size tumors died within 5 years. Of 90 patients, 75 (83%) were determined by physical examination to be free of tumor on at least one visit within 2 months of the completion of treatment (CR). The remaining 15 patients (17%) had physical findings suggestive of residual tumor (Residual). The overall 10-year survival rate for all patients with CR was 63%, compared with 10% for the patients with Residual (P < 0.0001). The incidences of distant metastases of the patients with or without local failure were 55 and 13%, respectively (P < 0.0001). The patients with local failure had significantly higher incidence of metastases. Most patients with small size tumor were treated with brachytherapy alone, and the survival rates of these patients were not improved by combination with external irradiation. CONCLUSION: These results suggest that tumor size was a significant prognostic factor for recurrent cervical cancer of the vaginal stump. Patients with small size tumors were recommended to be treated with brachytherapy alone.

Adult↗
PubMed1997

Depyrogenation of digestive enzymes reduces lipopolysaccharide tolerance in isolated cardiac myocytes.

The isolated myocyte is useful for examining the direct cardiac effects of substances such as lipopolysaccharide (LPS) and cytokines. However, the digestive enzymes used for standard cell isolation procedures are contaminated by several hundred ng/ml LPS. We depyrogenated the digestive enzymes with a series of Triton X-114 and Polymyxin B washes to remove 99.7-99.9% of the LPS. This lowered LPS contamination levels from 100-300 ng/ml to 0.15-0.70 ng/ml, while maintaining good quality cell isolations from the left ventricle of New Zealand white rabbits. We evaluated whether brief exposure to LPS contaminant levels, as occur during standard cell isolations, induces LPS tolerance. Cardiac myocytes (isolated with depyrogenated enzymes) were pre-exposed to 100 ng/ml LPS for 1 h, washed, then exposed to a challenge dose with 100 ng/ml LPS. The LPS challenge dose induced a time-dependent decrease in cell shortening over 6 h in myocytes without pre-exposure, but not in myocytes pre-exposed to an earlier dose of LPS. We examined whether LPS tolerance develops in myocytes isolated with untreated enzymes, compared with depyrogenated enzymes. In myocytes isolated with untreated enzymes, there was a significant decrease in cell shortening after 6 h exposure to 1000-10 000 ng/ml LPS. In myocytes isolated with depyrogenated enzymes, it required only 5-50 ng/ml LPS to induce a comparable cardiac depression. We conclude that brief exposure to LPS contaminant levels, which occur with standard cell isolation procedures, induces a hyporesponsiveness or tolerance to subsequent doses of LPS in isolated cardiac myocytes.

Animals↗
PubMed1997

Docosahexaenoic acid-rich fish oil does not enhance the elevation of serum transaminase and liver triacylglycerol induced by carbon tetrachloride in mice.

Carbon tetrachloride (CCl4) is metabolized to trichloromethyl radical and induces liver injury with elevated serum transaminase and increased hepatic triacylglycerols (TG). To answer the question whether dietary polyunsaturated fatty acids (PUFA) enhance free radical-mediated liver injury, a docosahexaenoic acid (DHA)-rich fish oil (FO) or a saturated and monounsaturated fatty acid-rich beef tallow diet was fed to mice for 4 wk and then CCl4 was administered. When thiobarbituric acid-reactive substances (TBARS) were measured in the absence of antioxidant the FO diet and CCl4 treatment markedly increased liver TBARS values synergistically, apparently supporting the interpretation that the highly autoxidizable DHA accelerates lipid peroxidation induced by CCl4. However,no such marked interaction was observed between diet and CCl4 treatment in liver TBARS values measured in the presence of an antioxidant in the assay mixtures as well as in conjugated diene contents. Furthermore, the FO diet did not enhance CCl4-induced elevation of serum transaminase but lowered liver TG levels. The proportion of DHA,the most easily autoxidizable among common PUFA, was increased but those of eicosanoid precursors were decreased in liver phospholipids by CCl4 treatment, possibly reflecting the inflammation-related mobilization of eicosanoid precursors but not lipid peroxidation. These results indicate that dietary enrichment with DHA does not enhance CCl4-induced liver injury through the so-called free radical-mediated propagative autoxidation of DHA in mice.

Alanine Transaminase↗
PubMed1997

Significance of monitoring plasma levels of amitriptyline, and its hydroxylated and desmethylated metabolites in prediction of the clinical outcome of depressive state.

The clinical significance of monitoring the plasma levels of amitriptyline and its metabolites in prediction of the clinical outcome of depressive episode was investigated in 49 inpatients. Discriminant analysis of drug concentrations (at two weeks after initiation of drug treatment) and clinical outcome revealed that increasing the plasma levels of amitriptyline, cis-isomers of hydroxylated metabolites (Z-10-hydroxyamitriptyline and Z-10-hydroxynortriptyline) predicted a better clinical outcome, while increasing of plasma levels of nortriptyline and trans-isomers of hydroxylated metabolites (E-10-hydroxyamitriptyline and E-10-hydroxynortriptyline) were shown to predict a poor clinical outcome in the depressive episode of the subjects, and that clinical outcome of approximately 73% of the subjects could be correctly predicted.

Adult↗
PubMed1997

A promoter for the first nine genes of the Escherichia coli mra cluster of cell division and cell envelope biosynthesis genes, including ftsI and ftsW.

We constructed a null allele of the ftsI gene encoding penicillin-binding protein 3 of Escherichia coli. It caused blockage of septation and loss of viability when expression of an extrachromosomal copy of ftsI was repressed, providing a final proof that ftsI is an essential cell division gene. In order to complement this null allele, the ftsI gene cloned on a single-copy mini-F plasmid required a region 1.9 kb upstream, which was found to contain a promoter sequence that could direct expression of a promoterless lacZ gene on a mini-F plasmid. This promoter sequence lies at the beginning of the mra cluster in the 2 min region of the E. coli chromosome, a cluster of 16 genes which, except for the first 2, are known to be involved in cell division and cell envelope biosynthesis. Disruption of this promoter, named the mra promoter, on the chromosome by inserting the lac promoter led to cell lysis in the absence of a lac inducer. The defect was complemented by a plasmid carrying a chromosomal fragment ranging from the mra promoter to ftsW, the fifth gene downstream of ftsI, but not by a plasmid lacking ftsW. Although several potential promoter sequences in this region of the mra cluster have been reported, we conclude that the promoter identified in this study is required for the first nine genes of the cluster to be fully expressed.

Bacterial Proteins↗
PubMed1997

Lipopolysaccharide induces cell shrinkage in rabbit ventricular cardiac myocytes.

The effects of 10 ng/ml of lipopolysaccharide (LPS) on cell volume were examined in rabbit left ventricular myocytes. The myocytes were isolated with depyrogenated digestive enzymes (< 0.7 ng/ml of LPS) to minimize tolerance. Myocyte cross-sectional area (CSA) did not change after 1 h of LPS. However after 8 h, the CSA decreased to 0.93 +/- 0.01 (SE) of the baseline CSA (time = 0) in 19 LPS-exposed myocytes compared with 1.00 +/- 0.01 in 13 control myocytes (P = 0.0015). LPS-induced cell shrinkage was completely blocked by coincubation with 1 mM N-monomethyl-L-arginine, indicating a nitric oxide-mediated mechanism. Cardiac guanosine 3',5'-cyclic monophosphate (cGMP) did not change after 1 h but increased 6 h after LPS (548 +/- 31 vs. 312 +/- 20 fmol/mg protein in control cells; P < 0.05). After 8 h, bumetanide (10 microM for 30 min), a Na+/K+/2Cl- cotransport inhibitor, decreased the CSA in 15 control myocytes to 0.92 +/- 0.02 of the baseline CSA. However, in 19 myocytes with a CSA of 0.93 +/- 0.01 of baseline after 8 h of LPS, the addition of bumetanide caused no additional cell shrinkage. We conclude that low levels of LPS increase cardiac cGMP to inhibit Na+/K+/2Cl- cotransport, causing significant cell shrinkage in cardiac myocytes.

Animals↗