Search PubMed⌕ Search

Biomedical subjects

T Shimada

Publications and source records attributed to T Shimada.

At least 505 records · Page 28Linked to original sources
PubMed1995

PCR-based detection of Wolbachia, cytoplasmic incompatibility microorganisms, infected in natural populations of Laodelphax striatellus (Homoptera: Delphacidae) in central Japan: has the distribution of Wolbachia spread recently?

Cytoplasmic incompatibility is caused in various insects by intracellular infection with rickettsia-like microorganisms of the genus Wolbachia. In Japan Laodelphax striatellus shows unidirectional cytoplasmic incompatibility between northeastern and southwestern populations. In this study, nine natural populations of L. striatellus collected from central Japan, including the geographic boundary between the two cytotype populations, were analysed for Wolbachia infection by PCR using primers specific to Wolbachia 16S rDNA. The geographic pattern of the infection rates of the southwestern (high) and the northeastern (low or zero) populations broadly resembled that of a previous study of incompatibility. In populations which originated from the boundary regions between the southwestern and northeastern populations, the infected and uninfected cytotypes coexisted. It is suggested that in some populations of L. striatellus, which formerly had been uninfected with Wolbachia, the infection property has changed to the infected. Based on our results, we conclude that the distribution of Wolbachia-infected L. striatellus populations have spread northeasterly during the last 12 years.

Animals↗
PubMed1995

Comprehensive treatment of advanced neuroblastoma involving autologous bone marrow transplant.

Encouraging results are reported with high-dose chemotherapy and total body irradiation followed by autologous bone marrow transplantation in the treatment of advanced neuroblastoma. However, relapse remains a significant problem. We used high-dose chemotherapy, surgery, intraoperative radiation and an autologous bone marrow transplant treated in vitro to remove tumor cells followed by 13-cis-retinoic acid to treat 36 children with advanced neuroblastoma. This comprehensive treatment appears to improve the survival rate of patients with advanced neuroblastoma, including those with N-myc amplification and bony involvement. The disease-free survival rate was 66% (95% confidence interval, 49-84%) at 3 years. All patients who received 13-cis-retinoic acid developed cheilitis, but no bone marrow depression occurred in these patients. Five patients developed hemolytic uremic syndrome (HUS) post-transplant. This may have been related to the procedure used for total body irradiation. Patients who had their kidneys shielded during this procedure did not develop this syndrome. Patients who received local irradiation at the primary site showed no evidence of relapse in this region, indicating that such therapy may help to prevent a relapse. These data suggest a high rate of 3 year disease-free survival with this treatment strategy. The nonrandomized nature of the study and use of multiple modalities precludes analysis of the specific contribution of each.

Adrenal Gland Neoplasms↗
PubMed1995

Successful autologous bone marrow transplant for relapsed Ki-1 lymphoma.

We report on a 16 year old girl with relapsed Ki-1 lymphoma and a very poor prognosis. The initial manifestation was multiple bone metastases and lymphadenopathy. The patient achieved remission with modified adriamycin, bleomycin, vincristine, daunomycine therapy. However, 14 months after the completion of therapy, relapse occurred in a new cervical lymph node on the left side. After preparation with chemotherapy and total lymphoid irradiation (TLI) the patient underwent autologous bone marrow transplantation (A-BMT). Ki-1 lymphoma shows clinically diverse symptoms, but hematopoietic stem cell transplantation should be performed in relapsed cases. It may be effective to give TLI followed by A-BMT for patients such as ours who have lymph node involvement without bone marrow metastasis.

Adolescent↗
PubMed1995

[Molecular epidemiological study on Vibrio cholerae O139].

Genomic DNA from 56 Vibrio cholerae O139 strains isolated in various countries was digested with Sfi I or Not I and analyzed by pulsed-field gel electrophoresis (PFGE). Eight different PFGE patterns were identified. Although the patterns of a large majority of CT-gene-positive epidemic strains isolated in India, Bangladesh and Thailand were the same or similar, but were slightly different from those of two CT-positive strains from India and Nepal. On the other hand, the patterns of CT-negative three strains from Argentine, Sri Lanka and Bangladesh were apparently different not only from each other, but also from those of epidemic CT-positive strains. The pattern of one V. cholerae O1 E1 Tor strain isolated in India and the pattern of epidemic V. cholerae O139 resemble each other in many points.

Anti-Bacterial Agents↗
PubMed1995

[Studies on Vibrio cholerae non-O1 isolated from diarrheal patients arrived from overseas].

Between the period January 1991 to June 1993, there were 23,976,238 travellers who arrived from overseas to Narita Airport, of which 20,501 stool specimens were collected from diarrheal patients for bacteriological examination, and infectious agents were detected from 2,751 cases (13.4%) including 250 cases (1.2%) of Vibrio cholerae non-O1. Countries suspected of infection of these patients were Thailand, the most in number, and followed by Indonesia, India and so on these mostly distributed in South-east or South Asia. About fifty percent of the patients were associated with abdominal pain and some with vomiting or fever. Diarrhea was mostly mild except in 16 patients who had severe diarrhea of more than ten times a day. 237 of the 250 isolated V. cholerae non-O1 strains were classified into 48 serogroups. There were 2 rough strains and 11 other strains which were out of the confirmed serogroups. Positive rate of these strains to haemolysin, cholera toxin (CT) and NAG-ST tests were 87.2, 0.4 and 0.8% respectively.

Cholera↗
PubMed1995

Characterization of Vibrio cgolerae non-O1 serogroups obtained from an outbreak of diarrhea in Lima, Peru.

In February 1994, an outbreak of diarrhea caused by non-O1 Vibrio cholerae occurred among volunteers in a vaccine trial study area in Lima, Peru. Clinically, 95% of the patients presented with liquid diarrhea with either no or mild dehydration. Serogrouping of 58 isolates recovered from diarrheal patients affected in the outbreak revealed seven different serogroups, with serogroups O10 (21%) and O12 (65%) being predominant. Most of these isolates were susceptible to a variety of antimicrobial agents. None of the 58 isolates hybridized with a DNA probe previously used to detect the gene encoding the heat-stable enterotoxin NAG-ST or produced cholera toxin as assessed by GM1 ganglioside enzyme-linked immunosorbent assay. Ribotyping exhibited 10 different BglI ribotype patterns among the 58 V. cholera non-O1 strains studied. However, ribotyping showed that all isolates belonging to serogroup O12 exhibited identical ribotypes and that 83% of the serogroup O10 isolates belonged to another identical ribotype, thus showing excellent correlation between ribotypes and serogroups. Among a group of O10 and O12 isolates selected for virulence studies, none produced enterotoxin whereas the majority produced a cytotoxin, as assessed in Y1 and HeLa cells. These isolates were also negative for the gene encoding zonula occludens toxin (Zot) as assessed by a PCR assay. The isolates tested showed strong adherence and some degree of invasion in the HEp-2 cell assay, whereas none of the isolates was positive in the PCR assay for the gene encoding the toxin coregulated pilus subunit A antigen (tcpA). In the removable intestinal tie adult rabbit diarrhea model, O10 and O12 serogroup isolates produced severe diarrhea and occasionally death when rabbits were challenged with 10(10) bacterial cells. Fluid accumulation was shown in the rabbit intestinal loop test when whole cultures were injected. No significant difference in virulence was shown between serogroup O10 and O12 isolates. This study provides further evidence that V. chlorae non-O1 non-O139 strains have diarrhegenic potential for humans through a yet-undefined mechanism(s) and that such strains can cause outbreaks.

Animals↗
PubMed1995

Characterization of Aeromonas trota strains that cross-react with Vibrio cholerae O139 Bengal.

It has previously been shown that Vibrio cholerae O139 Bengal shares antigens with V. cholerae serogroups O22 and O155. We detected six surface water isolates of Aeromonas trota that agglutinated in polyclonal antisera to V. cholerae O139 and V. cholerae O22 but not in antiserum to V. cholerae O155. On the basis of agglutinin-absorption studies, the antigenic relationship between the cross-reacting bacteria were found to be in an a,b-a,c fashion, where a is the common antigenic epitope and b and c are unique epitopes. The antigen sharing between A. trota strains and V. cholerae O139 was confirmed in immunoblot studies. However, A. trota strains did not react with two monoclonal antibodies specific for V. cholerae O139 and, consequently, tested negative in the Bengal SMART rapid diagnostic test for V. cholerae O139 which uses one of the monoclonal antibodies. A polyclonal antiserum to a cross-reacting A. trota strain cross-protected infant mice against cholera on challenge with virulent V. cholerae O139. All A. trota strains were cytotoxic for HeLa cells, positive for adherence to HEp-2 cells, and weakly invasive for HEp-2 cells; one strain was heat-stable toxin positive in the suckling mouse assay; however, all strains were negative for cholera toxin-like enterotoxin. Studies on bacteria that share somatic antigen with V. cholerae O139 may shed further light on the genesis of V. cholerae O139.

Aeromonas↗
PubMed1995

Evaluation of DNA probes for specific detection of Vibrio cholerae O139 Bengal.

Two DNA probes, 2R1 and 2R3, prepared from a region in the chromosome specific for the lipopolysaccharide O side chains of Vibrio cholerae O139 (M.K. Waldor and J.J. Mekalanos, Lancet 343:1366, 1994) were examined for their specificity and sensitivity. Both probes did not hybridize with any strain of V. cholerae belonging to serogroups other than O139 and to any of the other species examined belonging to the family Vibrionaceae. Among the 126 strains of V. cholerae O139 examined, probe 2R1 hybridized with 125 strains while probe 2R3 hybridized with all 126 strains. Both probes were found to be highly specific and sensitive and can be used for the specific identification of V. cholerae O139.

Bacteriological Techniques↗
PubMed1995

Clinical significance of S-T segment elevation in lead aVR in anterior myocardial infarction. Assessment by thallium-201 exercise scintigraphy.

The significance of exercise-induced S-T elevation in aVR was studied in 57 patients with recent anterior infarction and single-vessel disease. S-T elevation in aVR was found at peak exercise in 24 patients. Although the initial defect area was similar in the groups with and without S-T elevation in aVR, the redistribution area was larger in the former group (p < 0.01). When three electrocardiographic criteria were used in the multivariate analysis, S-T elevation in aVR was the significant variable related to redistribution in the anterior wall. Thus, S-T elevation in aVR may indicate ischemia of the anterior wall.

Adult↗
PubMed1995

Phasic right coronary blood flow in a patient with right ventricular hypertension using transesophageal Doppler echocardiography.

Although phasic right coronary artery blood flow in right ventricular hypertension has been studied in animals, reports on human subjects are not available. We observed right coronary artery blood flow before and after operation in a patient with right ventricular hypertension secondary to atrial septal defect using transesophageal Doppler echocardiography. Prior to surgery, blood flow was predominantly diastolic in both right and left coronary arteries. Reversal of right ventricular hypertension after surgery resulted in a change in the pattern of right coronary flow, with doubling of flow during systole.

Coronary Circulation↗
PubMed1995

Hepatocyte growth factor is the most potent endogenous stimulant of rabbit gastric epithelial cell proliferation and migration in primary culture.

Various growth factors are suggested to be involved in gastric mucosal repair. Our previous studies have shown that exogenous hepatocyte growth factor (HGF) has a proliferative effect on gastric epithelial cells. In the present study, comparison of the maximum proliferative effects and the optimum concentrations of several growth factors revealed that HGF was the most potent mitogen for gastric epithelial cells, as is the case for hepatocytes. Restitution of gastric epithelial cell monolayers was assessed using a round wound restitution model. HGF was the most effective agent for facilitating gastric epithelial restitution among those tested. A binding assay revealed specific binding of HGF to its receptor on gastric epithelial cells. Northern blot analysis confirmed the expression of specific HGF receptor mRNA (c-met) by gastric epithelial cells but not by gastric fibroblasts. To investigate endogenous HGF production, we determined the effect of gastric fibroblast-conditioned medium on epithelial proliferation and restitution. The conditioned medium produced similar effects to HGF and its activity was neutralized by an anti-HGF antibody. In addition, expression of HGF mRNA was detected in gastric fibroblasts but not in gastric epithelial cells. Our immunohistochemical study confirmed these in vitro data by means of demonstrating the existence and localization of HGF at human native gastric mucosa. HGF was localized at fibroblasts under the epithelial cell layer around gastric ulcers. These results suggest that HGF may be a potent endogenous promotor of gastric epithelial cell proliferation and migration, and may contribute to gastric mucosal repair through a paracrine mechanism.

Animals↗
PubMed1995

Isoenzyme patterns of glucose-6-phosphate dehydrogenase, malate dehydrogenase and lactate dehydrogenase in Babesia rodhaini and Babesia microti.

Glucose-6-phosphate dehydrogenase (G6PD), malate dehydrogenase (MDH), and lactate dehydrogenase (LDH) activities and their isoenzyme patterns in B. rodhaini (BR) and B. microti (BM), the two major causative species of murine babesiosis, were examined. G6PD and LDH activities were higher in BR than those in BM, whereas MDH activity was lower in BR than that in BM. No differences were observed between BR and BM in the mobility of isoenzyme bands of G6PD and MDH. On LDH isoenzyme pattern, at least 5 bands were detected in BR, while only one band in BM. Since each subunit of LDH is known to be coded by different gene, these results suggests that BR and BM are able to be differentiated genetically.

Animals↗
PubMed1995

Erythroleukemia in two cats naturally infected with feline leukemia virus in the same household.

Erythroleukemia was observed in two unrelated cats infected with feline leukemia virus (FeLV) from the same household. Case 1, a 1-year-old neutered male cat developed erythroleukemia (M6) after a diagnosis of myelodysplastic syndrome (MDS-Er) on the criteria of FAB classification of acute leukemias. Case 2, a 1-year-old neutered female cat, which had close contact with Case 1, also developed erythroleukemia (M6Er). In both cases, marked proliferation of erythroid progenitor cells with disproportionally large numbers of immature forms was observed in the bone marrow. In Case 1, neoplastic proliferation of myeloid cells in the bone marrow was also noted at the terminal stage. Combination chemotherapy with daunomycin was partially effective for treatment of these erythroid neoplasias, but did not induce complete remission. Southern blot analysis using exogenous FeLV-specific probes indicated the clonal origin of these hematopoietic tumor cells. Furthermore, the erythroid and myeloid tumor cells in Case 1 were shown to be derived from independent transformed clones. A variant FeLV was shown to be integrated into the tumor cells in Case 1, while a full-length FeLV was found in both cases. Because these erythroid neoplastic diseases occurred in two unrelated cats kept in the same household and these diseases are rare, they may both have been associated with the same FeLV strain.

Animals↗
PubMed1995

Enzyme activities related to glucose metabolism in Babesia microti and Babesia rodhaini.

A comparative study was carried out on the glucose metabolism in Babesia microti (BM) and Babesia rodhaini (BR) by analyzing the enzyme activities. The lactate dehydrogenase (LDH) activity in BM showed significantly lower values than that in BR, whereas citrate synthase (CS) and malate dehydrogenase (MDH) activities were remarkably higher in BM. In addition, pyruvate dehydrogenase (PDH), isocitrate dehydrogenase (ICDH), alpha-ketoglutarate dehydrogenase (KGDH), and succinate dehydrogenase (SDH) activities also tended to be higher in BM. Then, the change of enzyme activities related to the proliferation of parasites was examined. In BM infected mice, the parasitemia increased from day 15 to day 19 after inoculation (a.i.). While BM showed decrease of G6PD and LDH activities at day 19 a.i., it showed remarkably increased activities in CS and MDH (368 and 8,842 nmol/min.mg protein, respectively). In addition, PDH, ICDH, KGDH, and SDH activities also tended to increase from day 15 to 19 a.i. In BR infected mice, parasitemia increased from day 9 to day 12 a.i. LDH activity showed a considerable increase at day 12 a.i. (12,920 IU/mg.protein). Although CS and MDH activities also showed a slight increase at day 12 a.i., the activities of PDH, ICDH, KGDH and SDH didn't change from day 9 to 12 a.i. Since these changes observed in the enzyme activities of BM and BR seemed to be correlated with their proliferation, it was suggested that BM and BR depended on aerobic and anaerobic pathways, respectively, for their glucose metabolism.

Animals↗
PubMed1995

A short term in vitro cultivation of Babesia rodhaini and Babesia microti.

In vitro cultivation of Babesia rodhaini (BR) and Babesia microti (BM) was attempted. When RPMI1640 was supplemented with 30 or 40% of non-treated fetal bovine serum (FBS), the gas mixture of 3% CO2-8% O2 best supported the growth of both parasites. Under this optimized condition, the percent parasitized erythrocytes peaked to approximately 4- and 2-times initial values for Br and BM, respectively. The cultivated parasites retained the infectivity to the host mice. BM showed the characteristic feature of division during cultivation. However, the lots of FBS will have to be taken into consideration, since the FBS lots were shown to give large varieties to the results. Selection of the appropriate FBS lot may yield the better growth of these protozoa.

Animals↗
PubMed1995

Plasma methylguanidine and creatinine concentrations in cats with experimentally induced acute renal failure.

Plasma methylguanidine (MG) and creatinine (CRN) concentrations were measured in 11 cats with experimentally induced acute renal failure by a two-stage surgical procedure. According to the progression of renal failure, both plasma MG and CRN levels increased. A significant positive correlation (y = 0.187X - 0.379, lambda = 0.9176, P < 0.001) was found between plasma MG and CRN levels. These results suggested that the increase in plasma MG level was an available indicator for uremic status in cats.

Acute Kidney Injury↗