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Biomedical subjects

Kenji Kimura

Publications and source records attributed to Kenji Kimura.

25 records · Page 2Linked to original sources

A new filter-eluting solution that facilitates improved recovery of Cryptosporidium oocysts from water.

Cryptosporidium is a zoonotic coccidian parasite associated with diarrhea, and the disinfectant-resistant oocysts are threats to public health even in industrialized countries. In order to make an accurate assessment of the risk to public health, a detection method that has a high recovery rate of oocysts in water is required. In this study, we developed a new filter-eluting solution that facilitates more efficient recovery of Cryptosporidium oocysts from different kinds of water samples. The filter-eluting solution, referred to as PET, consists of sodium pyrophosphate (0.02%), Tween 80 (0.01%) and trisodium EDTA (0.03%). By using PET instead of conventional filter-eluting solutions, the average recovery rate significantly increased from 25.5+/-15.1% to 43.1+/-13.9% (p<0.05). The improved oocyst recovery was likely due to the increased separation of the oocysts from debris trapped on the filter membrane as well as increased capture of the oocysts by immunomagnetic beads. We recommend that PET be used as the filter-eluting solution for detection of Cryptosporidium oocysts in environmental water.

Animals↗

Biological properties and gene expression associated with metastatic potential of human osteosarcoma.

Lung metastasis has a great influence on the prognosis of patients with osteosarcoma. We previously established two high-metastatic sublines, M112 and M132, from the HuO9 human osteosarcoma cell line by in vivo selection. In this study, we newly isolated a high-metastatic subline, H3, and three low-metastatic sublines, L6, L12 and L13, from HuO9 by the dilution plating method. Three high-metastatic sublines produced more than 200 metastatic nodules in the lung, while three low-metastatic sublines produced no or few nodules after injection of 2 x 10(6) cells into the tail vein of nude mice. There were significant differences in the motility and invasiveness between high- and low-metastatic sublines, whereas the growth rates in vitro and the tumorigenicity in vivo showed no correlation with their metastatic abilities. Early adherence to culture plates was significantly lower in two of three low-metastatic sublines, which occupied smaller surface areas on the culture plates than other sublines did. Comparison of the expression of 637 cancer-related genes by cDNA microarray revealed that seven genes were differentially expressed between high- and low-metastatic sublines. Among them, five genes (AXL, TGFA, COLL7A1, WNT5A, and MKK6) were associated with adherence, motility, and/or invasiveness. These results suggest that the differences in motility/invasiveness and adhesive abilities are key determinants of lung metastasis in osteosarcoma.

Animals↗

Nuclear factor kappa B expression in peripheral blood mononuclear cells of patients with acute pancreatitis.

INTRODUCTION: Although many experimental studies have implicated the activation of nuclear factor kappa B (NF-kappaB) as a pivotal step in the pathobiology of acute pancreatitis, no clinical investigations have been reported. AIMTo investigate the expression of NF-kappaB and its characteristics in peripheral blood mononuclear cells (PBMCs) of patient with acute pancreatitis. METHODOLOGY: Forty-five patients were prospectively enrolled. The expression of NF-kappaB in PBMCs was measured in the patients by electrophoretic mobility shift assay at admission and 14 days after the onset of acute pancreatitis. Twelve healthy individuals were also included as control subjects. RESULTS: At admission, the PBMCs from patients with acute pancreatitis showed higher levels of NF-kappaB activities than did those from control subjects. In vitro, the lipopolysaccharide (LPS) treatment of the PBMCs from the control subjects and patients with mild pancreatitis induced further activation of the NF-kappaB. The response was significantly reduced in patients with severe pancreatitis. Patients who had persistently high NF-kappaB activities, a reduced response of NF-kappaB to LPS, and a low p50p65:p50p50 ratio after LPS stimulation at 14 days developed serious systemic complications in the later clinical course. CONCLUSIONS: An alteration of the characteristics of PBMCs occurs in the early phase of acute pancreatitis and may predispose patients to a higher risk of serious systemic complications.

Acute Disease↗

Alterations in the INK4a/ARF locus and their effects on the growth of human osteosarcoma cell lines.

Two different proteins, p16(INK4a) and p14(ARF), encoded by the INK4a/ARF locus play important roles in the RB and p53 pathways, respectively. This study was performed to determine genetic and epigenetic alterations in the INK4a/ARF locus and their effects on the growth of osteosarcoma. Among six cell lines examined, both p16(INK4a) and p14(ARF) exons were homozygously deleted in two cell lines, MG63 and HOS, and both p16(INK4a) and p14(ARF) promoters were methylated in one cell line, U2OS. Wild-type mRNA and proteins for p16(INK4a) and p14(ARF) were expressed in three other cell lines, SaOS2, HuO9, and G292. Transfection studies were performed using two cell lines, U2OS and MG63. Both the RB and p53 genes were wild types in U2OS, whereas p53 but not RB was mutated in MG63. Both p16(INK4a) and p14(ARF) suppressed the growth of U2OS, whereas p16(INK4a) but not p14(ARF) suppressed the growth of MG63. p53 only did not suppress the growth of MG63 either; however, coexpression of p14(ARF) with p53 increased the fraction of the G0/G1 phase in MG63 cells. The data presented here demonstrate the importance of genetic and epigenetic alterations in the INK4a/ARF locus for the growth of osteosarcoma and thus will be useful to further understand the biologic behavior of osteosarcoma in association with the defects in the p53 and RB pathways.

Blotting, Western↗

Establishment of human osteosarcoma cell lines with high metastatic potential to lungs and their utilities for therapeutic studies on metastatic osteosarcoma.

Relevant animal models for metastasis of osteosarcoma is needed to understand the biology and to develop the treatment modality of metastasis of human osteosarcoma. Therefore, we screened six human osteosarcoma cell lines for metastatic ability in nude mice. The HuO9 cell line was identified as being metastatic to the lung after intravenous injection. We established two sublines, HuO9-M112 and HuO9-M132, with high metastatic potential to the lung from the parental HuO9 cells by in vivo selection. There were no differences between these two sublines and the parental cells in the growth rate in vitro and the tumorigenicity after subcutaneous injection in nude mice, however, mice injected with the metastatic sublines became moribund earlier than mice injected with the parental HuO9 cells did. Thus, adriamycin (ADR) and recombinant interleukin-12 (IL-12) were administered to mice injected with the HuO9-M112 subline to suppress experimental lung metastases. Production of lung colonies was significantly suppressed and the prognoses of mice were significantly improved by both ADR and IL-12 treatments. These results indicate that both ADR and IL-12 are effective agents against pulmonary metastatic osteosarcoma, and that these sublines are useful for studies on the biological behavior and treatment of pulmonary metastatic osteosarcoma.

Animals↗

Hemiarthroplasty of the elbow with a vascularized fibular graft after excision of Ewing's sarcoma of the proximal ulna: a case report.

We report an 8-year-old girl with a Ewing's sarcoma in the right proximal ulna. The patient presented with pain in her right elbow, and plain radiographs showed destructive changes with a periosteal reaction in the proximal third of the ulna. A biopsy confirmed the diagnosis of Ewing's sarcoma. For preoperative chemotherapy, the patient received two courses of vincristine, doxorubicin and cyclophosphamide alternating with high-dose ifosfamide. MRI and angiography demonstrated that the chemotherapy was effective and therefore the patient underwent wide local excision of the tumor and reconstruction of the elbow joint using a vascularized fibular graft. Pathological examination of the resected specimen showed no evidence of viable tumor cells. After surgery, the patient received three courses of chemotherapy consisting of the same agents as those for the preoperative chemotherapy. Four years after surgery, there is no evidence of local recurrence or distant metastasis. Furthermore, the grafted bone is extending favorably and the patient has excellent function with active movement of the elbow.

Arthroplasty↗

Intestinal parasitic infections in Bekasi district, West Java, Indonesia and a comparison of the infection rates determined by different techniques for fecal examination.

This study was undertaken to determine the current status of intestinal parasitic infections among schoolchildren in West Java, Indonesia, and to compare the infection rates obtained by three different methods of fecal examination. A total of 285 fecal samples were collected from 131 males and 154 females at a junior high school. Samples were brought to the Department of Parasitology, Faculty of Medicine, University of Indonesia, and were examined for parasites by the Kato-Katz thick smear method (K-K). The residual samples were suspended in more than five volumes of 2% potassium dichromate solution and brought to the Department of Parasitology, Kobe University School of Medicine, Japan, where they were examined for parasites by the Army Medical School method (AMS III) and by the Sucrose Centrifugal Flotation method (SFL). The K-K revealed a total of two helminths with a prevalence of 10% (29/285). In contrast, nine species of parasites, 31% (89/285) positive, were obtained by AMS III, while 10 species, 22% (62/285) were found by SFL. Overall, 12 species of parasites were detected by the three methods: four species of nematoda (Trichuris trichiura, Ascaris lumbricoides, hookworm, and Enterobius vermicularis); five species of protozoa (Giardia intestinalis, Entamoeba histolytica-like cyst, E. coli, Cyclospora sp, Blastocystis hominis); two unidentified species of nematode eggs; and one unidentified species of mite egg.

Adolescent↗