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Biomedical subjects

Shiro Takahara

Publications and source records attributed to Shiro Takahara.

At least 19 recordsLinked to original sources

Carbamylated erythropoietin protects the kidneys from ischemia-reperfusion injury without stimulating erythropoiesis.

Several studies have shown that erythropoietin (EPO) can protect the kidneys from ischemia-reperfusion injury and can raise the hemoglobin (Hb) concentration. Recently, the EPO molecule modified by carbamylation (CEPO) has been identified and was demonstrated to be able to protect several organs without increasing the Hb concentration. We hypothesized that treatment with CEPO would protect the kidneys from tubular apoptosis and inhibit subsequent tubulointerstitial injury without erythropoiesis. The therapeutic effect of CEPO was evaluated using a rat ischemia-reperfusion injury model. Saline-treated kidneys exhibited increased tubular apoptosis with interstitial expression of alpha-smooth muscle actin (alpha-SMA), while EPO treatment inhibited tubular apoptosis and alpha-SMA expression to some extent. On the other hand, CEPO-treated kidneys showed minimal tubular apoptosis with limited expression of alpha-SMA. Moreover, CEPO significantly promoted tubular epithelial cell proliferation without erythropoiesis. In conclusion, we identified a new therapeutic approach using CEPO to protect kidneys from ischemia-reperfusion injury.

Animals↗

Targeting of interstitial cells using a simple gene-transfer strategy.

BACKGROUND: Interstitial fibroblasts are central to the inflammatory response during the progression of tubulointerstitial fibrosis. We examined the efficiency of a new gene transfer method that targets interstitial cells by using parenchymal injection of DNA followed by electroporation. METHODS: Fluoresceinisothiocyanate-labelled oligodeoxynucleotides (FITC-ODNs) or expression vectors were directly injected into the cortex of the kidney, followed by electroporation. RESULTS: Transfection with FITC-ODNs or the EGFP expression vector resulted in efficient transfection in interstitial fibroblasts, but not in tubular epithelial cells or glomerular cells. Transfection efficiency was optimal after using a total of 150 microg of DNA in 1000 microl of PBS, combined with clamping of the renal vessels prior to electroporation. Gene expression peaked at 4 days after transfection and decreased by two orders of magnitude at 6 weeks post-transfection; however, expression recovered to near peak levels after parenchymal or intraperitoneal injection of FR901228, a histone deacetylase inhibitor. CONCLUSION: We demonstrated that direct parenchymal injection of DNA combined with electroporation enables gene transfer into interstitial fibroblasts.

Animals↗

Reduction in chronic allograft nephropathy by inhibition of p38 mitogen-activated protein kinase.

BACKGROUND: Chronic allograft nephropathy (CAN) is the major cause for late graft loss and is therefore a key target for therapy. METHODS: The impact of p38 mitogen-activated kinase (MAPK) on CAN was investigated by administering FR167653 (32 mg/kg/day), a specific inhibitor of p38 MAPK, for 4 weeks in addition to conventional cyclosporine therapy (1.5 mg/kg/day for 5 days) in an established experimental rat transplantation model. RESULTS: Transplanted rats develop glomerulosclerosis, arterial obliteration, interstitial fibrosis and tubular atrophy, all of which are characteristic of CAN, resulting in shortened survival on 32 weeks. However, the inhibition of p38 MAPK by daily subcutaneous treatment with FR167653 resulted in reduced CAN with preserved renal function and prolonged survival. The FR167653-treated rats had fewer phosphorylated p38 MAPK-positive cells in treated kidneys. Concomitantly, the expression of monocyte chemoattractant protein-1/CCL2 and transforming growth factor-beta(1) was markedly reduced. CONCLUSION: These results suggest that p38 MAPK phosphorylation is involved in the pathogenesis of CAN and provide evidence that p38 MAPK is a novel, appealing therapeutic target for combating CAN.

Animals↗

Incidence of positive C4d deposition in long-term survival cases over 10 yr after renal transplantation.

BACKGROUND: The incidence of positive C4d deposition in peritubular capillaries (PTC) in long-term survival cases remains controversial. Some incidences of positive C4d deposition in PTC in cases of long-term survival less than 10 yr have been reported. We retrospectively examined the incidence of positive C4d deposition in long-term survival cases over 10 yr after renal transplantation and the histological and clinical characteristics of the positive C4d staining cases. METHODS: We examined 14 protocol biopsy cases performed at Osaka University Hospital between March 2004 and March 2005. The average interval between the operation and the day of biopsy was 15.4 yr. Histological diagnosis was made in accordance with the Banff 97 classification. Paraffin-embedded tissue was stained with polyclonal anti-C4d antibody. Detection of donor-specific antibody (DSA) was determined by flow cytometric assay. The cases were divided according to C4d positivity. RESULTS: Three of 14 cases (21.4%) were C4d positive and belonged to the C4d+/DSA+ group, while 11 cases were of the C4d-/DSA- group. There were no significant differences between the two groups in serum creatinine (sCr) or proteinuria at the time of biopsy. A trend towards decreasing rate of the inverse of sCr (1/sCr) in the C4d+/DSA+ group was noted. In the C4d+/DSA+ group, three transplant glomerulopathy (TGP) were identified. On the other hand, TGP were identified in six of 11 cases of the C4d-/DSA- group. We investigated the relevance of typical chronic rejection (CR) features and the positivity of C4d. No significant differences were observed between the CR features and C4d depositions in PTC (p = 0.26). CONCLUSION: In long-term survival cases with positive C4d, a trend towards decreasing rate of 1/sCr was revealed, but their histological characteristic features was not recognized.

Adult↗

ABO-incompatible kidney transplantation with anti-CD20 monoclonal antibodies, intravenous immunoglobulin and plasmapheresis without splenectomy: a case report.

A 24-yr-old man was admitted to our hospital for ABO-incompatible kidney transplantation. His blood type was O, and the donor's (his father's) blood type was B. The recipient had pancytopenia, splenomegaly, splenorenal shunts and esophageal varices due to congenital hepatic fibrosis. Therefore, if splenorectomy was performed, the blood pressure of the portal vein and the growth of esophageal varices were predicted. Eventually, in return for splenectomy, anti-CD20 monoclonal antibodies (rituximab), intravenous immunoglobulin and plasmapheresis was performed for additional immunosuppression. Because of progression of pancytopenia, we had to decrease the dose of mycophenolate mofetil and gave up on using deoxyspagalin. Nevertheless the serum creatinine level decreased and remained in the 1.6 to 1.8 mg/dl range.

ABO Blood-Group System↗

Renal cell carcinoma in dialysis patients: a single center experience.

AIM: Renal cell carcinoma (RCC) is a life-threatening complication of end-stage renal disease with an unclear pathogenesis. We evaluated RCC developing in patients undergoing dialysis. METHODS: In 2624 patients undergoing hemodialysis or continuous ambulatory peritoneal dialysis at our hospital between July 1993 and March 2004, we performed annual screening for RCC using abdominal computed tomography and ultrasonography. Patients diagnosed with RCC underwent radical nephrectomy as well as clinical and pathologic evaluation. RESULTS: RCC was detected in 44 patients (1.68%; 31 males and 13 females). The age of RCC patients was 55.5 +/- 11.1 years. Dialysis duration before RCC diagnosis was 11.2 +/- 7.2 years. Most RCC were early stage and low stage by TNM classification, 43 patients had N0M0 RCC, whereas one had N1M0. Tumor size was 2.9 +/- 1.9 cm. The predominant histological type of RCC was common or conventional cell-type carcinoma (clear cell carcinoma and granular cell carcinoma). Of patients, 5(11.4%) had bilateral RCC, and satellite tumor lesions in RCC were detected in 13 (29.5%). In 36 patients (81.8%) RCC was accompanied by acquired cystic disease of the kidney. These patients had longer dialysis durations (P = 0.01) and smaller tumors (P = 0.048). RCC metastasized postoperatively in 4 patients (9.1%), while one (2.3%) died of cancer. CONCLUSIONS: Our dialysis patients showed a higher incidence of RCC than the general population. Prognosis was favorable because tumors were detected by screening when they were small. Therefore, periodical screening for RCC seems very important in dialysis patients.

Adult↗

[Case report of skin tuberculosis after living renal transplantation].

We report on a mycobacterium tuberculosis after renal transplantation. This is, to our knowledge, the first case report on an isolated skin tuberculosis with mycobacterium tuberculosis after renal transplantation. A-68-year-old renal transplant recipient presented with a nodule in his right breast. A diagnosis of a mycobacterium tuberculosis skin infection was made and antimycobacterial therapy was started.

Aged↗

[Living unrelated renal transplantation in an eldery couple: a case report].

We present a 60-year-old female who underwent living unrelated renal transplantation from her 62-year-old husband. The primary immunosuppression consisted of tacrolimus, mycophenolate mofetil and steroid. We did not recognize any rejection in a histopathological study. The total ischemic time to carry out anastomosis of the two renal arteries was 121 minutes. After hemodialysis 5 times for acute tubular necrosis, her renal function improved. She was discharged on the 33rd postoperative day when her serum cretinine level was 1.0 mg/dl. The graft function was stable at 6 months after transplantation. We discussed living unrelated renal transplantation in the elderly population in Japan.

Age Factors↗

Effect of Smad7 expression on metastasis of mouse mammary carcinoma JygMC(A) cells.

BACKGROUND: Transforming growth factor beta (TGF-beta) facilitates metastasis during the advanced stages of cancer. Smad6, Smad7, and c-Ski block signaling by the TGF-beta superfamily proteins through different modes of action. We used adenovirus-mediated gene transfer of these natural inhibitors in a mouse model of breast cancer to examine the roles of TGF-beta superfamily signaling in tumor growth and metastasis. METHODS: We systemically administered, by intravenous injection, adenoviruses (AdCMV) containing the mouse cDNAs for Smad7, Smad6, c-Ski, the c-Ski mutant c-Ski (ARPG), or LacZ (control) to nude mice (>19 mice/group) bearing tumors derived from mouse mammary carcinoma JygMC(A) cells, which spontaneously metastasize to lung and liver, and examined their effects on survival and metastasis. High-throughput western blotting analysis was used to examine the expression levels for 47 signal transduction proteins in JygMC(A) cells and primary tumors. We also investigated the proliferation, migration, and invasion of JygMC(A) cells that stably overexpressed Smad6 or Smad7. Nonparametric comparisons were done by Kruskal-Wallis H statistic and Wilcoxon's rank sum tests. Parametric comparisons were done by one-way analysis of variance or two-sided unpaired Student's t tests. All statistical tests were two-sided. RESULTS: Control mice bearing tumors derived from JygMC(A) cells showed many metastases to the lung and liver; all animals died by 50 days after cell inoculation. By contrast, mice treated with AdCMV-Smad7 or AdCMV-c-Ski demonstrated a dramatic decrease in metastasis and statistically significantly longer survival than control mice (Smad7 versus LacZ: medium survival = 55 days versus 41 days, difference = 14 days [95% confidence interval {CI} = 6 days to 22 days], P < .001), whereas mice treated with AdCMV-Smad6 or AdCMV-c-Ski (ARPG) did not. Expression of Smad7 in JygMC(A) cells was associated with increased expression of major components of adherens and tight junctions, including E-cadherin, decreased expression of N-cadherin, and decreases in the migratory and invasive abilities of the JygMC(A) cells. CONCLUSION: Smad7 inhibits metastasis, possibly by regulating cell-cell adhesion. Systemic expression of Smad7 may be a novel strategy for the prevention of metastasis of advanced cancers.

Adenoviridae↗

A novel immunosuppressant FTY720 ameliorates proteinuria and alterations of intrarenal adrenomedullin in rats with autoimmune glomerulonephritis.

FTY720 has been originally developed as a new immunosuppressive agent, which prolongs graft survival in organ transplantation. Adrenomedullin (AM) participates in the regulation of sodium homeostasis and has renoprotective effects. The possible involvement of renal AM in the pathophysiology of glomerulonephritis (GN) and the effect of FTY720 has been evaluated in rats. HgCl2 (1 mg/kg body weight) was inoculated subcutaneously 3 times/week for a total of 2 weeks. FTY720 (3 or 10 mg/kg) was inoculated subcutaneously daily. The proteinuria, urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion and serum total cholesterol levels were increased and serum albumin level was reduced in rats with HgCl2-induced GN compared with controls. FTY720 reduced proteinuria (3 mg/kg: -25%; 10 mg/kg: -41%), urinary NAG excretion (-11%; -52%) and total cholesterol level (-21%; -55%) in a dose-dependent manner. Renal AM level and its mRNA expression were increased in rats with GN compared with controls (Peptide Cortex: +69%; Medulla: +82%; mRNA Cortex: +25%). Interestingly, FTY720 additionally increased these levels (Peptide Cortex: +38%; Medulla: +39%; mRNA Cortex: +20%). Renal AM levels correlated with urinary NAG excretion and creatinine clearance. These results suggest that FTY720 suppresses the renal damage in rats with GN and renal AM may participate in the pathophysiology of GN and the renoprotective effects of FTY720.

Adrenomedullin↗

Preoperative administration of FTY720 prolonged renal allograft survival.

BACKGROUND: FTY729 is an immunomodulator obtained by chemical modification of Myriocin(ISI-1) which exists in the culture filtrate of an ascomycete, Isaria sinclairii. It has been reported that postoperative administration of FTY720 prolonged survival of various kinds of transplanted organs. In the present study, we evaluated the effect of 2-day preoperative administration of FTY 720 on graft survival. MATERIALS AND METHODS: We used a rat renal transplantation model in which Wistar King Aptekman Hokkaido (WKAH, RT1K) served as the organ donor and Lewis (LEW, RTl) as the recipient. FTY720 was given to the recipients consecutively 2 days (day-2, day-1) before transplantation at the doses of 1, 3 or 5 mg/kg/day. Renal allograft survivals, hematological parameters of recipient blood and phenotypic analysis of recipient splenic cells and graft infiltrate were evaluated. RESULTS: Consecutive 2-day preoperative oral administration of FTY 720 at the doses of 1, 3 or 5 mg/kg/day significantly prolonged WKAH allograft survivals compared with those of the untreated recipients. The number of peripheral blood lymphocytes was markedly decreased in the recipients treated with FTY720 at the doses of 3 mg/kg/day or 5 mg/kg/day on the 5th postoperative day. Preoperative FTY 720 administration significantly decreased the number of CD4 positive cells and the percentage of interleukin 2 receptor (IL-2 R) positive cells infiltrating both spleen and allograft at the dose of 3 mg/kg/day or 5 mg/kg/day. CONCLUSION: FTY 720 could act as a safe and potent immunomodulator by decreasing the number of peripheral lymphocytes, especially CD4 positive cells and IL-2R positive cells when it is given to the recipient preoperatively.

Animals↗

Retroperitoneoscopic living related-donor nephrectomy: clinical outcomes of 50 consecutive cases and comparison with open donor nephrectomy.

PURPOSE: To determine whether living related retroperitoneoscopic donor nephrectomy (RDN) is a safe and effective procedure. PATIENTS AND METHODS: From September 2001 to May 2004, RDN was performed in 50 consecutive patients at our hospital. All patients were followed longitudinally with office visits. Perioperative and postoperative data for these RDNs, including operative time, blood loss, and complications, were compared with those of open donor nephrectomies (ODNs) performed between January 1999 and December 2001. RESULTS: The RDN was completed in all cases. The average warm ischemia times were 4.1 minutes (range 1.0-8.5 minutes) and 3.5 minutes (range 2.3-5.5 minutes) in the RDN and ODN groups, respectively (P = NS). The mean operative time for RDN was significantly longer than that for ODN (P < 0.001), but patients in the RDN group had significantly shorter hospital stays (P < 0.05). There was no significant difference between the groups in blood loss during operation or number of doses of analgesics administered after the operation. Perioperative and early postoperative complications occurred in 14 patients (28%) in the RDN group and consisted of subcutaneous emphysema in 9, wound infection in 3, and persistent headache in 2 patients. All kidneys removed retroperitoneoscopically functioned immediately. No recipients required post-transplant continuous hemodialysis. CONCLUSIONS: The RDN is a safe and effective procedure for both donor and recipient. Although the benefits of RDN have been demonstrated, further long-term studies of graft function and patient survival are needed.

Adult↗

Prevalence, characteristics, and outcome of BK virus nephropathy in Japanese renal transplant patients: analysis in protocol and episode biopsies.

BACKGROUND: BK virus nephropathy (BKN) is recognized as a cause of graft loss in renal transplant patients. This may be related to the introduction of new and potent immunosuppressive regimens. In Japan, our experience regarding its prevalence, clinical significance, and outcome is still limited. In this study, our primary purpose is to outline the prevalence, outcome, and clinical characteristics of BKN as observed at Osaka University Hospital. METHODS: We retrospectively analyzed 112 biopsy specimens from 87 renal transplant patients. All transplantations were from living donors. Of the 112 biopsy specimens, 71 were from protocol biopsies and 41 were from episode biopsies. Calcineurin inhibitors and corticosteroid were used in all patients (tacrolimus 32 and cyclosporin 55). In addition, azathioprine was used in 43 patients, mizoribine was used in 24 patients, and mycophenolate mofetil was used in 20 patients. BKN was diagnosed by light microscopic examination and a positive immunohistochemical staining of anti-SV40 antibody in a biopsy specimen. In order to investigate the outcome and potential risk factors of patients with different histological staging, we divided the patients into groups A (mild histological change) and B (moderate or severe histological change). RESULTS: Of the 87 patients, six were diagnosed with BKN. There were no significant differences between BKN patients and non-BKN patients, except for the number of patients with graft loss (p < 0.001). Of the six BKN patients, three were in group A, and three were in group B. We recognized a significant difference between group A and group B in terms of anti-rejection treatment including glucocorticoid, tacrolimus trough levels of over 8 ng/mL, episode of acute rejection within 1-month post-transplantation, and the time period between transplantation and BKN diagnosis. CONCLUSIONS: This is the first report of BKN in Japanese renal allograft recipients. In our hospital, the prevalence, risk factors, and outcome were similar to those previously for non-Japanese recipients.

Adult↗

Long term efficacy of simvastatin in renal transplant recipients treated with cyclosporine or tacrolimus.

BACKGROUND: Hyperlipidemia is frequently developed following renal transplantation and results in worsening of the patient's prognosis. METHODS: In this study, 14 patients who had hypercholesterolemia [total cholesterol (TC) >200 mg/dL] and hypertriglyceridemia [triglyceride (TG) >150 mg/dL] 1 month after renal transplantation (post-transplantation), seven patients each under the treatment with immunosuppressant, either cyclosporine or tacrolimus started simvastatin treatment of 5-10 mg/d and continued the treatment for 4 yr. The effect of simvastatin treatment was assessed by comparison in serum lipid levels (TC, TG, cholesterol in lipoprotein fractions, and apolipoproteins) and the lipid metabolism related enzyme activities for post-transplantation, after 6-month and 4-yr simvastatin treatment. RESULTS: Simvastatin treatment of 4 yr significantly decreased the elevated levels of serum TC from 234.5 +/- 30.8 to 186.3 +/- 20.5 mg/dL (p < 0.001), low density lipoprotein cholesterol (LDL-C) from 116.7 +/- 22.5 to 82.7 +/- 16.6 mg/dL (p < 0.05) and TG from 200.3 +/- 109.2 to 97.0 +/- 45.2 mg/dL (p < 0.001). In addition, there were significant decreases in elevated serum very-low-density lipoprotein cholesterol (VLDL-C) from 47.8 +/- 18.4 to 28.6 +/- 9.5 mg/dL (p < 0.001) and LDL2 cholesterol (LDL2-C) from 20.8 +/- 8.2 to 5.7 +/- 1.8 mg/dL (p < 0.001). CONCLUSION: The results indicate that 4-yr treatment of simvastatin improves profiles of the atherogenic lipids in renal transplant patients with immunosuppressant caused hypercholesterolemia and hypertriglyceridemia treated either cyclosporine or tacrolimus in similar manner.

Adult↗

[A case of five metachronous primary cancers].

We report a case of five metachronous primary cancers completely resected during 39 years. An 80-year-old woman had been diagnosed with and treated for bilateral breast cancers, gastric cancer, sigmoid colonic cancer, Bowen's disease and renal pelvic cancer. These cancers were found as metachronous cancers and were surgically treated. This is the first case of completely resected metachronous five cancers in Japan.

Aged↗

[A case of synchronous double primary cancers of prostate, and bladder in a hemodialysis patient: a case report].

A 60-year-old male, who had been maintained on hemodialysis for 4 years, visited our hospital to receive living renal transplantation. He complained of macrohematuria, and preoperative examination showed elevation of psostate specific antigen (PSA). Cystoscopy revealed papillary tumors on the right lateral bladder wall. Transurethral resection of bladder tumor (TUR-Bt) was performed and histopathological examination showed transitional cell carcinoma, G2, pTa. The histologic diagnosis of the transrectal needle prostate biopsy specimen was moderately differentiated adenocarcinoma. Combined androgen blockade as a neoadjuvant therapy and radical prostatectomy were performed. A case of synchronous double primary cancers, comprised of adenocarcinoma of the prostate and transitional cell carcinoma of the urinary blader in a hemodialysis patient has never been previously reported in the Japanese literature.

Adenocarcinoma↗