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Biomedical subjects

H Kashiwabara

Publications and source records attributed to H Kashiwabara.

At least 19 recordsLinked to original sources
PubMed2004

Simplified method for cryopreservation of islets using hydroxyethyl starch and dimethyl sulfoxide as cryoprotectants.

Cryopreservation is an ideal method for long-term storage of human islets. Dimethyl sulfoxide (DMSO) has been used as an intracellular cryoprotectant. However, because of its toxicity, DMSO has to be added stepwise and diluted stepwise with sucrose. We combined hydroxyethyl starch (HES) as an extracellular cryoprotectant with DMSO to simplify the freeze-thawing procedure. Islets were isolated from the pancreas of beagle dogs by an automated digestion method and Ficoll purification. After overnight culture, the islets were cryogeneically stored using cooling by a programmed freezing system. After 4-week storage in liquid nitrogen, the container was rapidly thawed in a 37 degrees C water bath. The function of the islets was assessed upon static incubation immediately after thawing, showing a recovery rate of 71.16% +/- 20.14% and a stimulation index of 1.80 +/- 0.78. In conclusion use of HES allowed a decrease in DMSO concentration and simplified the freeze-thawing procedure for islets.

Animals↗
PubMed2001

Long-term assessment of posttransplant renal prognosis with 31 P magnetic resonance spectroscopy.

BACKGROUND: 31P-magnetic resonance spectroscopy (MRS) has been widely used to study pretransplantation renal viability, and although some had discussed posttransplant renal viability, no one has examined long-term posttransplant renal prognosis. We discuss the use of 31P-MRS to assess the long-term prognosis from the time when MRS was performed. METHODS: We studied 20 patients with renal allografts. 1.5 Tesla clinical magnetic resonance imaging (MRI) and 15 cm surface coil was used for 31P-MRS. Localized 31P-MRS was done using image selected in vivo spectroscopy (ISIS) method. Individual peaks were fitted by Lorenzian line-shapes with a least square method and peak area ratios were calculated. RESULTS: A beta-adenosine triphosphate/inorganic phosphate (beta-ATP/Pi) ratio >1.2 had sensitivity of 92.8%, specificity of 100%, and accuracy of 95% for predicting 3-year renal survival; a beta-ATP/Pi ratio >1.2 had sensitivity of 90.9%, specificity of 66.7%, and accuracy of 76.9% for predicting 5-year renal survival. We compared 31P-MRS spectra data between the survived group and failed group. The survived group had significantly higher beta-ATP/Pi, alpha-ATP/Pi, and phosphodiester (PDE)/Pi ratios than the failed group. CONCLUSIONS: We discussed the beta-ATP/Pi value as a parameter for predicting long-term survival of a transplanted kidney from the time when MRS was performed. A value above 1.2 suggests a high probability of 3-year renal survival, whereas a value over 2.5 indicates that the transplanted kidney could survive over 5 years. 31P-MRS may be useful for predicting long-term survival of transplanted kidneys, but additional studies are needed.

Adult↗
PubMed2001

Long-term outcomes of immunosuppressed renal transplant recipients with malignancies.

This study analyzes ten cases of malignancy in a cohort of 183 renal transplant recipients, examining surgical management, postoperative immunosuppressive therapy, and long-term outcome. One of these ten patients, who had malignant lymphoma of the jejunum, died of the neoplasm, but the other nine patients did not show any signs of tumor recurrence after removal. All of these nine patients, except for one who had transplant renal cell carcinoma (RCC), received the same dose of immunosuppressive agents after surgery for the malignant disease. Seven patients were still alive at the time of this report, six of whom had good transplant renal function. The findings of this study indicate that even if immunosuppressive agents predispose to the development of cancer, it is not necessary to reduce their dose after removal of the tumor.

Adult↗
PubMed2001

Successful surgical treatment of renal cell carcinoma in a transplanted kidney from a cadaveric donor: report of a case.

Posttransplant renal cell carcinoma (RCC) usually arises in the native kidneys of renal transplant recipients rather than in the transplanted kidney. This report describes a case of RCC that developed in the transplanted cadaveric kidney in a 37-year-old male recipient 9 months after transplantation. An en bloc radical transplant nephrectomy was performed, and he has subsequently remained stable on hemodialysis for 3 years without any sign of recurrence.

Adenocarcinoma↗
PubMed2001

Heterogeneity of DNA methylation status analyzed by bisulfite-PCR-SSCP and correlation with clinico-pathological characteristics in colorectal cancer.

Aberrant DNA methylation has been identified as an important mechanism for inactivation of tumor suppressor genes and mismatch repair genes during carcinogenesis. We used bisulfite treatment and the PCR-single strand conformation polymorphism (SSCP) (BiPS) technique to analyze methylation status of the promoter regions of the hMLH1, p16, and HIC1 genes in several cancer cell lines and colorectal cancer tissues. The methylation of the hMLH1, p16 and HIC1 genes was observed in 2, 8, and 13 of 13 cancer cell lines, respectively. The SSCP for p16 and HIC1 in each of the methylation-positive cell lines were similar, indicating relative homogeneity of methylation status and complete methylation in the cell lines. Methylation was observed in 8, 5, and 21 of 25 colorectal cancer tissues for the hMLH1, p16, and HIC1 genes, respectively. The methylated bands revealed by BiPS analysis of the hMLH1 gene were homogeneous, whereas those of the p16 and HIC1 genes were different in each case. The methylation of the promoter region of the HIC1 gene in colorectal cancer was observed most frequently and could serve as a sensitive marker for colorectal cancer. Methylation status of the hMLH1 and p16 gene promoters was correlated with microsatellite instability status, tumor location, and differentiation but not with K-ras mutation or allelic loss of p53.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Enhanced detection of deleterious and other germline mutations of hMSH2 and hMLH1 in Japanese hereditary nonpolyposis colorectal cancer kindreds.

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal, dominantly inherited cancer-prone syndrome. Here, we describe a novel and efficient approach for screening mutations of two major HNPCC susceptibility genes, hMSH2 and hMLH1. The system consists of RNA extraction from whole blood treated with the translation inhibitor, followed by long RT-PCR of the entire coding regions combined with direct sequencing. In analysis of 15 kindreds suspicious for HNPCC, 8 samples were subjected to analysis after puromycin treatment and 7 samples were analyzed without puromycin treatment. Three deleterious mutations were detected in the kindreds with puromycin treatment, while none were observed in those without puromycin. Signals from mutated alleles were enhanced after puromycin treatment and easily distinguished from the wild-type allele, achieved by suppression of nonsense-mediated mRNA decay. Furthermore, 12 other mutations were detected in 15 kindreds. The system is considered to be a reliable and useful approach for detecting germline mutations of hMSH2 and hMLH1 in HNPCC kindreds.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Insulin levels during fasting and the glucose tolerance test and Homa's index predict subsequent development of hypertension.

OBJECTIVE: To determine whether there is a longitudinal relationship between hypertension and hyperinsulinemia and to find the most useful parameter(s) for predicting the subsequent development of hypertension. SUBJECTS AND METHODS: The oral glucose (75 g) tolerance test (OGTT) was performed in 313 patients, who were divided into three groups according to glucose tolerance based on the WHO criteria: normal, borderline and diabetes mellitus. The fasting insulin (IRI) levels, sigmaIRI (the sum of the insulin levels 0, 30, 60 and 120 min after the OGTT), insulinogenic index and Homa's index, a candidate for the simple assessment of insulin sensitivity, of the normotensive and hypertensive subjects in each subgroup were compared. In addition, 145 normotensive subjects were followed up for over 3 years and observed for the development of hypertension. RESULTS: Hypertensive diabetic subjects had not only higher fasting IRI levels and sigmaIRI values, but they also had higher Homa's indices than normotensive diabetics. Normotensive subjects with normal glucose tolerance (n = 20) did not develop hypertension. However, 16 out of 94 patients with borderline glucose tolerance and five out of 31 diabetics became hypertensive. The incidence of hypertension in the group with fasting IRI > or = 15, sigmaIRI > or = 150 or Homa's index > or = 4 was between 5 and 9 times higher than that in the group with fasting IRI < 10, sigmaIRI < 100 or Homa's index < 2. This difference was still significant when multivariate analysis, including various factors such as age, body mass index (BMI) and sex, was performed. CONCLUSIONS: These results suggest that higher plasma IRI levels and/or insulin resistance are closely related to the pathogenesis of hypertension in patients with diabetes mellitus. Homa's index, fasting and sigmaIRI may be useful predictors of the subsequent development of hypertension.

Adult↗
PubMed1999

DNA methylation analysis using bisulfite treatment and PCR-single-strand conformation polymorphism in colorectal cancer showing microsatellite instability.

The combination of bisulfite treatment and PCR-single-strand DNA conformation polymorphism (SSCP) analysis is proposed for quantitative methylation assay. We applied this procedure to the methylation analysis of the hMLH1 promoter region in colorectal cancer. An analysis of mixtures of known amounts of methylated and unmethylated DNA revealed a linear relation. Using a calibration curve, proportions of methylated DNA were calculated. The hMLH1 promoter region was highly methylated in about 80% of microsatellite instability (MSI) (+) colorectal cancers, but in none of the MSI(-) colorectal cancers. A significant correlation existed between hypermethylation of the hMLH1 promoter and MSI, as in previous reports. In conclusion, bisulfite-PCR-SSCP (BiPS) analysis could be applied to the rapid identification of methylation status in multiple samples, quantification of methylation differences, and detection of methylation heterogeneity in amplified DNA fragments.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Effect of matching of class I HLA alleles on clinical outcome after transplantation of hematopoietic stem cells from an unrelated donor. Japan Marrow Donor Program.

BACKGROUND: The requirements with respect to HLA compatibility and the relative importance of matching for individual class I and class II HLA alleles in the transplantation of hematopoietic stem cells from unrelated donors have not yet been established. METHODS: We performed retrospective DNA typing of alleles at 11 polymorphic loci of HLA genes in 440 recipients of hematopoietic stem cells from unrelated donors who were serologically identical with their respective recipients for HLA-A, B, and DR antigens. Of these recipients, 80 percent had leukemia; the rest had lymphoma, marrow failure, or a congenital disorder. RESULTS: Multivariate analysis showed that incompatibility for HLA-A alleles and incompatibility for HLA-C alleles were independent risk factors for severe acute graft-versus-host disease (GVHD) (HLA-A, P=0.006; HLA-C, P=0.001). Mismatching of HLA-A, but not of HLA-C, alleles was an independent risk factor for death (P<0.001). Matching [corrected] of HLA-C alleles was a significant risk factor for relapse of leukemia (P=0.035). HLA-B disparity was a significant risk factor for both GVHD and death in the univariate analysis, but not in multivariate analysis. Disparities in class II HLA alleles of the DRB1, DQA1, DQB1, DPA1, and DPB1 loci were not identified as significant risk factors for acute GVHD or death in the multivariate analysis. CONCLUSIONS: Genomic typing of class I HLA alleles adds substantially to the success of transplantation of hematopoietic stem cells from unrelated donors, even if the donors are serologically identical to their recipients with respect to HLA-A, B, and DR antigens.

Adolescent↗
PubMed1998

Beneficial effects of renal transplantation on cardiovascular disorders in dialysis patients.

The present study was conducted to evaluate the impact of successful renal transplantation against the cardiovascular risk factors of patients on maintenance dialysis in whom cardiovascular accidents are the most common cause of death. A total of 74 renal transplant patients with grafts that had been functioning well for longer than 6 months after transplantation were examined before and 6-250 months after transplantation. The mean age was 34 years and the duration after transplantation was 104 +/- 66 months. An improvement in anemia from hemoglobin level of 9.0 to 13.6 g/dl and a decrease in mean systolic blood pressure from 157 +/- 24 to 135 +/- 14 mm Hg (P < 0.001) were observed after transplantation. An elevation in RV5 + SV1 levels by 0.6 mV on electrocardiogram (P = 0.042) was seen without any change in the cardiothorathic ratio on chest X-ray. Echocardiographic measurements of six recipients revealed great improvements in the left ventricular systolic dimension and thickness of the posterior wall of the left ventricle. Moreover, the ejection fraction and fractional shortening rose significantly from 59.4% +/- 16.3% to 75% +/- 8.1%, and from 30.6% +/- 9.2% to 44.8% +/- 7.9% (P = 0.017), respectively. These findings clearly show that successful renal transplantation can significantly improve the cardiovascular function of renal patients on maintenance dialysis.

Adolescent↗