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Biomedical subjects

K Araki

Publications and source records attributed to K Araki.

At least 91 records · Page 5Linked to original sources
PubMed2000

Gnathostomiasis possibly caused by Gnathostoma malaysiae.

Gnathostomiasis is rarely reported in travelers, although the disease remains a major public health problem in Southeast Asia. A creeping eruption and Quincke's edema (slowly migrating erythema with pruritus) appeared in two Japanese men who had eaten raw freshwater shrimp in Myanmar. A Gnathostoma larva was found in subcutaneous tissue from one of the men. Four species causing human gnathostomiasis, G. hispidum, G. doloresi, G. nipponicum and G. spinigerum, can be distinguished based on the number of nuclei in intestinal epithelial cells of infected larvae, in cross-section. In G. hispidum, only a single large nucleus is found. Morphologically, our larva was initially identified as G. hispidum. However, since the number of epithelial cells was greater and the body width was larger than those of a "large-type" 3rd-stage larva of G. hispidum, the larva was then identified as a 3rd-stage larva of G. malaysiae, Miyazaki and Dun, 1965, as reported by Setasuban et al, (1991). Since no human cases caused by this species of Gnathostoma have previously been encountered, this appears to be the first report of gnathostomiasis due to G. malaysiae.

Animals↗
PubMed2000

[Evaluation of the diagnostic reagents which detect rotavirus and adenovirus with the immunochromatographical method].

Dipstick 'Eiken' Rota and Dipstick 'Eiken' Adeno were the reagents used for the diagnosis of viral acute gastroenteritis using the immunochromatographical method. Dipstick 'Eiken' Rota and Dipstick 'Eiken' Adeno were evaluated for their sensitivity and specificity. Dipstick 'Eiken' Rota had a capacity to detect a purified rotavirus antigen in a concentration of 50 ng/ml. The sensitivity of Dipstick 'Eiken' Rota was 10 times higher than the sensitivity of the latex agglutination tests (Serodirect 'Eiken' Rota and ROTALEX DRY) and was almost the same as the immunochromatography test (Immu- noCard ST ROTAVIRUS) and the simplified EIA (TESTPACK ROTAVIRUS). With a concentration of 25 ng/ml, Dipstick 'Eiken' Adeno detected a purified adenovirus antigen. Dipstick 'Eiken' Adeno also detected adenovirus antigen in 64 higher dilutions than the latex agglutination test (ADENOLEX DRY). When Dipstick 'Eiken' Rota was compared with Serodirect 'Eiken' Rota among 100 fecal specimens of healthy children and children with viral acute gastroenteritis, the sensitivity was 100.0%, the specificity was 98.0%, and the agreement was 97.0%. When Dipstick 'Eiken' Adeno was compared with ADENOLEX DRY among 55 fecal specimens of healthy children and children with viral acute gastroenteritis, the sensitivity was 100.0 , the specificity was 93.8%, and the agreement was 96.4%. Dipstick 'Eiken' Rota and Dipstick 'Eiken' Adeno are found to be useful diagnostic assays for viral acute gastroenteritis in the clinical laboratories.

Adenoviridae↗
PubMed1999

Mutant mice lacking Crk-II caused by the gene trap insertional mutagenesis: Crk-II is not essential for embryonic development.

Crk family adapter proteins including Crk-II, Crk-I, and Crk-L consist mostly of SH2 and SH3 domains. Through the interactions between SH2 domain and phosphotyrosine residues and/or between SH3 domain and proline-rich motifs, they are involved in a variety of signaling cascades. Despite their essential roles in the signal transductions, knock-out mice of these molecules have not been reported yet. We performed the gene trap insertional mutagenesis with a trap vector, pU-Hachi, and generated a mutant mice line, Ayu 8104, in which the trap vector was inserted into the c-crk gene. Homozygous Ayu 8104 mice lacked Crk-II and Crk-I transcripts but expressed the truncated Crk proteins retaining one SH2 and one SH3 domain. Since the structure of the truncated proteins was similar to that of Crk-I, the insertion was considered to cause Crk-II-specific disruption. Homozygous mutant mice, however, did not exhibit any obvious abnormalities, suggesting that Crk-family adapters, Crk-II, Crk-I, and Crk-L would redundantly function in the signaling cascades and Crk-II was not apparently essential for embryonic development.

Animals↗
PubMed1999

Massive outbreak of Escherichia coli O157:H7 infection in schoolchildren in Sakai City, Japan, associated with consumption of white radish sprouts.

In July 1996, an outbreak of Escherichia coli O157:H7 infection occurred among schoolchildren in Sakai City, Osaka, Japan. This outbreak developed in 13 North-East District and 34 Middle-South District elementary schools in the city. All children hospitalized on July 17-19 had presented on July 8 (North-East District) and July 9 (Middle-South District). School lunches served on July 1 and 8 in the North-East District and on July 1, 4, 8, and 9 in the Middle-South District were proposed by a food consumption study to be associated with infection. White radish sprouts from a single farm were the only uncooked food common to the most highly implicated meals on the involved days in two school districts (sweet and sour chicken with lettuce on July 8 in the North-East District and chilled Japanese noodles on July 9 in the Middle-South District). Two incidents of E. coli O157:H7 in neighboring areas were also related to white radish sprouts from the farm. The pulse-field gel electrophoresis patterns of isolates from patients in these two districts and the neighboring areas were identical. Thus, it was concluded that the cause of the outbreak was the white radish sprouts shipped on July 7-9 from one particular farm.

Child↗
PubMed1999

Geographical variations in the concentration of biliary free fatty acids with anti-mutagenic action.

The concentrations and compositions of free fatty acids (FFAs) in human bile, especially of inhibitory free fatty acids (IFFAs), were analyzed in terms of anti-mutagenic effects in relation to the mutagenic activity of bile. Bile samples were collected from patients with cholelithiasis residing in either Niigata or Kochi prefectures of Japan, regions characterized as the highest and lowest risk areas for gallbladder cancer (GBC), respectively. Biliary FFAs and IFFAs were analyzed by high-performance liquid chromatography and mutagenicity was examined in by the Ames test (TA98+S9mix) after blue rayon treatment. There was a tendency for higher biliary FFA and IFFA concentrations in the Kochi subjects, but the proportion of IFFA to the total FFA concentration did not differ between the two areas. There was an inverse correlation between the concentrations of IFFAs and the numbers of revertant colonies in both Niigata and Kochi subjects. However, at a dose of 591 micromol/l, (calculated based on the average amount of IFFAs absorbed in blue rayon) IFFAs did not exhibit anti-mutagenic actions in the blue rayon extracts. Within this range, more positive samples were seen in Niigata than in Kochi, suggesting the presence of more active mutagen(s) in Niigata samples.

Adult↗
PubMed1999

Mice homozygous for a truncated form of CREB-binding protein exhibit defects in hematopoiesis and vasculo-angiogenesis.

CREB-binding protein (CBP) and the closely related adenovirus E1A-associated 300-kD protein (p300) function as coactivators of transcription factors such as CREB, c-Fos, c-Jun, c-Myb, and several nuclear receptors. To study the roles of CBP in embryonic development, we generated CBP homozygous mutant mouse embryos that expressed a truncated form of CBP protein (1-1084 out of 2441 residues). The embryos died between embryonic days 9.5 (E9.5) and E10.5 and exhibited a defect in neural tube closure. They appeared pale and showed decreases in erythroid cells and colony-forming cells (CFCs) in the yolk sac, suggesting defects in primitive hematopoiesis. Immunohistochemistry with an anti-PECAM antibody showed a lack of vascular network formation. Organ culture of para-aortic splanchnopleural mesoderm (P-Sp) with stromal cells (OP9) showed an autonomous abnormality of putative endothelial precursors, which may induce the microenvironmental defect in hematopoiesis. In addition, these defects were partially rescued by the addition of VEGF to this culture. Our analyses demonstrate that CBP plays an essential role in hematopoiesis and vasculo-angiogenesis.

Animals↗
PubMed1999

Low p27 expression correlates with poor prognosis for patients with oral tongue squamous cell carcinoma.

BACKGROUND: p27, a cyclin-dependent kinase inhibitor, regulates progression from G1 to S phase. There have been a few clinical reports of low p27 expression associated with poor survival among patients with cancer; however, there have been no reports of such an association in cases of head and neck cancer. The authors investigated whether p27 expression in patients with oral tongue squamous cell carcinoma was associated with their prognosis. METHODS: Ninety-four patients with oral tongue squamous cell carcinoma were analyzed. The authors performed p27 immunohistochemistry on all patients and Western blot analysis on 19 available patients. Cox proportional hazards regression analysis that included gender, history of smoking and alcohol usage, presence of multiple primary cancers, stage, histologic grade, and p27 status was used to identify the multivariate predictive value of prognostic factors. RESULTS: Twenty-six patients had high p27 expression (> or =50% tumor cell nuclei positive), and 68 patients had low p27 expression (<50%) by immunohistochemistry. In those with low p27 expression, N(+) and advanced T (T3 or T4) were significantly higher than in those with high p27 expression (P = 0.02 and 0.04). The 5-year survival rate in the low p27 group was 44%, whereas that in the high p27 group was 68%, indicating a significant difference (P = 0.04). p27 expression was inferred from Western blot analysis, and an arbitrary quantity (<1, 1-5, or > or =5) from the ratio of tumor to normal tissue density was used to characterize, resulting in 8 (42%), 3 (16%), and 8 (42%) patients in the low (<1-fold), intermediate (1-5-fold), and high (> or =5-fold) groups, respectively. Results of immunohistochemical analysis for p27 were significantly correlated with those of Western blot analysis (P = 0.02). Multivariate analysis revealed that low intensity of p27 expression and advanced stage (Stage III or IV) were predictors of reduced survival (P = 0.02 and 0.001). CONCLUSIONS: Low p27 expression was associated with increasing lymph node metastasis and stage of tumor and resulted in a poor prognosis for patients with oral tongue squamous cell carcinoma. p27 is apparently a significant predictor of survival.

Actins↗
PubMed1999

Epidemiology of rotavirus in infants and protection against symptomatic illness afforded by primary infection and vaccination.

This study assessed the frequency of symptomatic and asymptomatic primary and secondary infections with rotavirus in children under 24 months and determined protection against symptomatic illness afforded by rhesus and human-rhesus rotavirus reassortant vaccines. Successive cohorts of children (n 236) were followed through five winter rotavirus seasons with cultures of each reported episode of diarrheal disease and serologic determination of rotavirus exposure on paired sera bracketing the winter. An average of 46% of children experienced rotavirus infection in each season with almost all infected by two years of age. The relative risk of rotavirus associated gastroenteritis in naive children versus naturally immune children was 2.4 (1.1, 5.3). The relative risk of rotavirus associated gastroenteritis in naive children versus vaccinees was 4.1 (1.6, 10.7). In a community with predominantly serotype G1 rotavirus rhesus rotavirus-based vaccines are as protective against rotavirus gastroenteritis as prior natural infection.

Antibodies, Viral↗
PubMed1999

Comparison of ES cell fate in sandwiched aggregates and co-cultured aggregates during blastocyst formation by monitored GFP expression.

Markers and the means to detect them are required to monitor the fate of living cells. However, few suitable markers for living cells were known until a green fluorescent protein (GFP) was discovered. We have established mouse embryonic stem (ES) cell lines that express mutant GFP under the chicken beta-actin (CAG) promoter. Using these cell lines, we were able to follow the migration of ES cells during blastocyst formation both in sandwiching and coculture methods, even if only a single ES cell was used. Furthermore, the contribution of ES cells to the inner cell mass (ICM) was easily estimated at the blastocyst stage. We compared sandwiching with coculture aggregation relative to the contribution of the ES cell in the ICM, and the results indicated that there was no difference in the ratios of chimeric embryos having ICM contributed from cultured ES cells. Furthermore, an aggregated single ES cell was able to contribute three or four cells to the ICM at the blastocyst stage. Thus we conclude that one, instead of two, embryos is enough to make aggregation with ES cells, and a single ES cell attached to an embryo is enough to produce germline chimeras. Moreover, we could clearly observe single cell fate during blastocyst formation. This suggests that our established cell line can be used for monitoring single cell fate in vivo. In addition, we have shown that up to five doses of 30 sec of UV irradiation using GFP filters have no effect on the embryonic development.

Animals↗
PubMed1999

Esophageal carcinoma showing a long stricture due to prominent lymphatic permeation: report of a case.

Some esophageal diseases such as carcinoma, esophagitis, and collagen diseases have often been reported to show a diffusely thickened esophageal wall in the roentogenogram findings. In the current report, a preoperative upper gastrointestinal series and an endoscopic examination showed a diffusely infiltrative type carcinoma, but other examinations did not suggest any diseases such as esophagitis or collagen diseases which might cause a thickening of the esophageal wall or a constriction of the esophagus. A postoperative histological examination revealed the primary carcinoma to remain only within the mucosal layer, while a large degree of lymphatic vessel permeation reached the adventitia over a wide area. An extraordinary degree of lymphatic permeation spread through the esophageal wall, and stromal fibrosis developed as a result of such lymphatic permeation. These histological phenomena might thus have led to the macroscopic appearance of infiltrative type esophageal carcinoma.

Carcinoma, Squamous Cell↗
PubMed1999

Brain-derived neurotrophic factor regulates the expression of AMPA receptor proteins in neocortical neurons.

The role of the neurotrophins; nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3 and neurotrophin-4/5, in synaptic development and plasticity has been extensively investigated. The neurotrophins regulate synaptic transmission as well as neural development in the brain. However, the mechanisms underlying these processes are unknown. In this study we show that brain-derived neurotrophic factor triggers an increase in alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor (GluR) proteins without significant changes in their messenger RNA levels. Brain-derived neurotrophic factor treatment specifically increased the protein levels of GluR1 (193+/-22%) and GluR2/3 (182+/-11%) in cultured rat neocortical neurons. In contrast, nerve growth factor and neurotrophin-3 failed to alter the protein levels of these neurons, and brain-derived neurotrophic factor effects on N-methyl-D-aspartate-type glutamate receptors were either modest or negligible. Immunocytochemical studies indicated that the increase in AMPA receptor proteins reflects the induction of their neuronal expression, but not selective neuronal survival. In agreement with these results, cortical neurons from brain-derived neurotrophic factor-knockout mice exhibited a reduction in AMPA receptor proteins in the cytoskeletal fraction containing postsynaptic proteins. Thus, the neurotrophin plays a crucial role in modulating the expression of AMPA receptors presumably at translational or post-translation levels and is implicated in synaptic development and plasticity.

Animals↗
PubMed1999

Skin cancer screening in Okinawa, Japan.

Depletion of the ozone layer has been observed on a global scale. Ozone depletion increases the amount of biologically harmful solar ultraviolet radiation (UV) that reaches the surface of the Earth, leading to an increased incidence of skin cancer. We previously reported the prevalence and incidence of actinic keratosis (AK) in Kasai City, which is located almost at the center of Japan. To evaluate the effects of different ambient annual UV doses on the prevalence and incidence of non-melanoma skin cancer and AK in Japan, we screened for skin cancer on Ie Island in Okinawa at the southern end of Japan, where the annual cumulative dose of UV is assumed to be the highest in Japan. The island had a population of 5562 in 1993. A prospective 4-year population-based study on the prevalence and incidence of cutaneous neoplasms was conducted by examining the sun-exposed skin of people over 40 years of age living on Ie Island. In 1993 1996, 86 cases of AK, nine of basal cell carcinoma (BCC), and two of squamous cell carcinoma were identified. The annual prevalence of AK on Ie Island was 1159.4 in 1993, 572.8 in 1994, 1014.3 in 1995 and 988.9 per 100000 Japanese in 1996. These values were significantly higher than those in Kasai City. The annual age-adjusted odds ratios for AK of Ie Island to Kasai City were 2.79, 1.38, 2.45 and 2.39, respectively. The incidences of AK on Ie Island per 100,000 were 637.0 in 1995 and 625.5 in 1996, which were also significantly higher than those in Kasai City (223.6 in 1993 and 171.2 in 1994). The prevalence of BCC was 123.6 and the incidence was 26.1. Together with our previous reports, the present results show a possible inverse relationship between the prevalence and incidence of AK and latitude among Japanese people.

Adult↗
PubMed1999

Measurement and prediction of hydrophobicity parameters for highly lipophilic compounds: application of the HPLC column-switching technique to measurement of log P of diarylpyrazines.

In the preparatory stage of structure-activity relationship (QSAR) studies of anti-platelet aggregant pyrazine derivatives, log P values (P: 1-octanol/water partition coefficient) of diarylpyrazines were measured by a newly developed HPLC column-switching technique. The system consists of two processes: (1) adsorption of the sample at the top end of a short precolumn, and then (2) quantifying the enriched analyte by a conventional analytical column. By using the log P values thus obtained, the correction factor for the steric hindrance caused by the vicinal diphenyl groups was estimated. The log k values (k; retention factor) were also measured with methanol-buffer (pH 7.4) eluents and related to log P. The eluent of 50% methanol content (M50) gave a good linear relationship over a wide range of log P (-0.3< log P < 5.2), indicating that log k(M50) parameter is useful for predicting the log P value.

Chemical Phenomena↗
PubMed1999

Detection of bone invasion by gingival carcinoma of the mandible: a comparison of intraoral and panoramic radiography and computed tomography.

OBJECTIVE: To assess the diagnostic accuracy of panoramic radiography (PR), panoramic radiography combined with intraoral radiography (PR+IR), and CT in detecting the supero-inferior extent of tumor invasion of the mandible by gingival carcinoma. METHOD: PR, PR+IR, and CT images of the mandible in 37 patients with gingival carcinoma were evaluated by five oral radiologists for the supero-inferior extent of bone invasion using ROC analysis. The mean ROC curve area (Az) of each observer for the different imaging modalities was analysed by nonparametric two-way ANOVA. P<0.05 was considered statistically significant. RESULTS: The mean Az for the detection of bone invasion were 0.88+/-0.03 for PR, 0.77+/-0.12 for PR+IR, and 0.87+/-0.03 for CT (P=0.0907). The mean Az for the detection of bone invasion beyond the alveolus was 0.89+/-0.07 for PR, 0.85+/-0.08 for PR+IR, and 0.83+/-0.06 for CT (P=0.5438). The mean Az for the detection of bone invasion beneath the mandibular canal were 0.94+/-0.04 for PR, 0.94+/-0.02 for PR+IR, and 0.91+/-0. 04 for CT (P=0.2466). No statistically significant differences were observed in Az between PR, PR+IR, and CT. CONCLUSION: We consider that PR+IR should be adopted as the initial imaging modality to determine the extent of supero-inferior invasion of the mandible in gingival carcinoma.

Analysis of Variance↗
PubMed1999

Truncated CBP protein leads to classical Rubinstein-Taybi syndrome phenotypes in mice: implications for a dominant-negative mechanism.

A mouse model of Rubinstein-Taybi syndrome (RTS) was generated by an insertional mutation into the cyclic AMP response element-binding protein (CREB)-binding protein (CBP) gene. Heterozygous CBP-deficient mice, which had truncated CBP protein (residues 1-1084) containing the CREB-binding domain (residues 462-661), showed clinical features of RTS, such as growth retardation (100%), retarded osseous maturation (100%), hypoplastic maxilla with narrow palate (100%), cardiac anomalies (15%) and skeletal abnormalities (7%). Truncated CBP is considered to have been acting during development as a dominant-negative inhibitor to lead to the phenotypes of RTS in mice. Our studies with step-through-type passive avoidance tests and with fear conditioning test showed that mice were deficient in long-term memory (LTM). In contrast, short-term memory (STM) appeared to be normal. These results implicate a crucial role for CBP in mammalian LTM. Our CBP +/- mice would be an excellent model for the study of the role of CBP in development and memory storage mechanisms.

Animals↗
PubMed1999

Alternating combination chemotherapy COP (cyclophosphamide, vincristine, prednisone) and MP (melphalan, prednisone) in multiple myeloma: a multicenter phase II study (JCOG8906). Lymphoma Study Group of the Japan Clinical Oncology Group.

BACKGROUND: The main form of cytotoxic treatment for multiple myeloma (MM) is conventional dose chemotherapy at present. METHOD: Between November 1989 and December 1991, a multicenter phase II study of alternating conventional dose combination chemotherapy (CCT) with COP (cyclophosphamide, vincristine, prednisone) and MP (melphalan and prednisone) to evaluate its clinical usefulness for overt MM patients was conducted by the Lymphoma Study Group of the Japan Clinical Oncology Group (JCOG). RESULTS: Eighty-one previously untreated patients were enrolled in the study. For 69 eligible patients, the response rate was 50.7% [95% confidence interval (CI) 38.4-63.0%]. The median survival time was 38.5 (95% CI 32.0-44.4) months. The survival rate at 3 and 5 years was 50.7 and 27.3%, respectively. Grade 4 toxicity by the criteria of the World Health Organization consisted of anemia in eight patients, leucocytopenia in three, cardiac in one and hepatic in two, but there was no treatment-related death. CONCLUSION: The COP-MP regimen for overt MM is thought to be one of the effective CCTs according to the results of the present phase II study.

Adult↗