Biomedical subjects

Junji Uchida

Publications and source records attributed to Junji Uchida.

31 records · Page 2Linked to original sources

PubMed2003

Cadaveric renal transplantation from a non-heart-beating pediatric donor into adult recipients.

INTRODUCTION: The use of cadaveric pediatric kidneys has been suggested as a means to overcome organ shortage, but is debated because of technical complications and an increased incidence of functional allograft impairment. METHODS: We experienced 2 cases of cadaveric renal transplantation from a non-heart-beating pediatric donor. RESULTS: In our cases, transplanted kidneys achieved good graft function and proteinuria due to glomerulosclerosis was not recognized. CONCLUSION: Previous reports indicate that in transplantation from pediatric donors into adults recipients, glomerular sclerosis occurs as the reason for impairment of grafts. Further, cadaveric renal transplantation from a non-heart-beating donor has a warm ischemia time and an increased risk of hyperfiltrated injury and graft failure. If transplantation of pediatric kidneys into adults from a non-heart-beating donor is performed, BMI and BSA must be carefully considered in the selection of recipients in order to avoid imbalance between nephron supply and metabolic demands and to insure successful, healthy grafts.

Body Mass Index↗

PubMed2003

Results of cadaver kidney transplantation with right renal vein extension.

INTRODUCTION: Several methods to lengthen the renal vein of the allografts have been proposed in order to secure the surgeon's field of vision and to allow appropriate positioning of the graft. However, its safety and complications have not been clarified. Furthermore, its long- and short-term results have not been investigated. Therefore, we studied the results of this operative procedure to confirm the safety of the technique. METHODS: The right renal vein extension was utilized when the donated right kidney from a cadaver donor had sufficient length of the inferior vena cava wall. The results of 10 patients who received kidney transplantation with renal vein extension were examined. RESULTS: None of the patients had vascular complications. The transplanted kidney functioned in all patients; 3- and 5-year graft survival was 100 and 75.0%, respectively. CONCLUSIONS: The results confirmed that this technique was safe and without complications and did not affect the long- and short- term results of patients who received cadaver kidneys. Therefore, we conclude that it is appropriate to adapt this technique when the physician judges the long renal vein suitable for the procedure.

Adult↗

PubMed2003

The prognostic role of atrial natriuretic peptides in hemodialysis patients.

BACKGROUND: It is well known that plasma atrial natriuretic peptide (ANP) is an indicator of extracellular fluid volume expansion and that plasma ANP is considered to be a marker for setting the proper dry weight of HD patients. Although the plasma ANP is a prognostic predictor of cardiac death, the prognostic role of ANP in HD patients has yet to be elucidated. In this study, we investigated the prognostic role of ANP in HD patients. METHODS: Plasma ANP concentrations were measured in 105 HD patients after HD. Multiple regression analysis was performed to determine the major factors causing increased plasma ANP concentrations. Cardiac mortality was monitored for 24 months after baseline analysis, and the prognostic role of ANP was examined by Cox proportional hazards regression analysis. RESULTS: Multiple regression analysis showed that cardiovascular disease (CD) and age were independent factors for elevated ANP (R2 = 0.298, p < 0.0001). During a 24-month follow-up period, cardiac death occurred in 11 patients. Kaplan- Meier survival estimates of patients from varying plasma ANP levels (<50 and >50 pg/ml) differed between the two groups (p < 0.0001). The group with the higher ANP level (>50 pg/ml) had the lower survival. When compared with patients with ANP <50, the hazard ratios for cardiac death of patients with ANP of >50 pg/ml were 32.0 (95% confidence interval (CI) 4.1 to 252.4). Univariate Cox proportional hazards model showed that ANP, left ventricular ejection fraction (LVEF), LVMI, age, serum albumin and C-reactive protein (CRP) were significantly associated with the risk of cardiac mortality. By stepwise multivariate Cox proportional hazards analysis, only ANP, LVMI and CRP remained powerful independent predictors of cardiac death. The relative risk ratios were 3.483 (95% CI 1.640-7.397) for ln ANP, 1.023 (1.008-1.038) for LVMI, and 1.379 (1.115-1.705) for CRP. CONCLUSION: High plasma ANP level of post-HD were strongly associated with CD and age. Post-HD ANP level may be a reliable parameter for assessing the risk for cardiac death in HD patients by providing prognostic information independent of other variables previously reported.

Aged↗

PubMed2003

Renin mRNA expression and renal dysfunction in tacrolimus-induced acute nephrotoxicity.

Tacrolimus is a superior immunosuppressive agent and has markedly improved the short-term outcome of renal allografts. Despite the beneficial effects of maintaining immunotolerance in organ transplant recipients, it has well-characterized side effects on renal hemodynamics in the early phase. The mechanism of tacrolimus-induced acute nephrotoxicity is still unclear. The purpose of this study was to elucidate the role of renin-angiotensin system (RAS) in tacrolimus-induced acute nephrotoxicity. We examined the renal mRNA levels of renin in order to elucidate the relationship between plasma renin activity (PRA) and tacrolimus-induced renal dysfunction. Daily administration of tacrolimus (4 mg/kg/day) for 2 weeks in spontaneously hypertensive rats (SHR) significantly increased BUN and plasma creatinine (P-Cr) level, while endogenous creatinine clearance (Ccr) significantly decreased in tacrolimus treated rats. Regarding tubular function data, fractional excretion of Na (FENa) and fractional excretion of K were higher in the tacrolimus treated group. Renin mRNA levels in the renal cortex in tacrolimus treated rats significantly increased when compared to the vehicle-treated rats. Ccr level was inversely proportional to PRA, with a high correlation coeffecient. The rise in PRA significantly correlated with increase in FENa by liner regression. Therefore, the results indicate that RAS is involved in the tacrolimus-induced acute nephrotoxicity.

Animals↗

PubMed2002

Dissection of B cell differentiation during primary immune responses in mice with altered CD40 signals.

CD40 is essential for efficient humoral immune responses. CD40 has two cytoplasmic domains required for binding of tumor necrosis factor receptor-associated factors (TRAF). The TRAF6-binding site is within the membrane proximal cytoplasmic (Cmp) region, while a PXQXT motif in the membrane distal cytoplasmic (Cmd) region needs to engage TRAF2/3/5. To dissect CD40 signals necessary for B cell differentiation, we generated transgenic mice expressing wild-type and mutant human CD40 (hCD40) molecules in a mouse CD40-deficient (mCD40(-/-)) background. The B cell-specific expression of hCD40 in mCD40(-/-) mice resulted in T-dependent antibody responses including germinal center (GC) formation. Mutant hCD40 molecules that carry either a point mutation of the TRAF2/3/5-binding site or a deletion of the Cmd region rescued extrafollicular B cell differentiation but not GC formation. A mutant hCD40 that comprises of only the TRAF2/3/5-binding site in the cytoplasmic region also rescued low but significant titers of antigen-specific IgG1 without GC formation. These results demonstrated that two distinct signals either from the Cmp or from the Cmd region induced the extrafollicular B cell differentiation and Ig class switching; however, GC formation required both. We conclude that combinations of these two signals determine which of the extrafollicular or the follicular (GC) differentiation pathway B cells enter.

Animals↗

PubMed2002

Role of renin-angiotensin system and nuclear factor-kappaB in the obstructed kidney of rats with unilateral ureteral obstruction.

The present study was conducted to elucidate the role of oxidative stress and nuclear factor-kappaB (NF-kappaB) in the beneficial effects of angiotensin receptor blockade on obstructive nephropathy. Unilateral ureteral occlusion in rats elicited tubulo-interstitial fibrosis with concomitant macrophage infiltration and increased expression of monocyte chemoattractant protein-1. These changes were accompanied by an induction of renal cortical lipid peroxidation and activation of NF-kappaB. Both an AT(1) antagonist, candesartan, and a NF-kappaB inhibitor, pyrrolidine dithiocarbamate, markedly attenuated these changes and to a similar extent. These results suggest that the beneficial effects of angiotensin blockade are mediated by the inhibition of oxidative stress and subsequent NF-kappaB activation in obstructive nephropathy.

Angiotensin Receptor Antagonists↗

PubMed2002

Hepatocyte growth factor ameliorates renal hemodynamic disorder after ischemia/reperfusion.

Ischemic injury of the transplanted kidney is one of the causes of reduced graft survival. The purpose of the present experiment was to examine whether hepatocyte growth factor (HGF) would improve acute renal hemodynamic recovery immediately after cold ischemia. Addition of HGF to the preservation solution during 3 h cold ischemia of dog kidney accelerated both recovery of renal blood flow and glomerular filtration rate (GFR). It is suggested that HGF may be useful for preservation of excised kidney for transplantation. As intrarenal arterial infusion of HGF in normal dog kidney had no effects on renal hemodynamics, mechanisms other than direct vasodilator action of HGF appear to be operating in the protection.

Animals↗

PubMed2002

Nephrogenic adenoma of the bladder: two case reports and literature review.

In the two cases we report here, tumors were diagnosed as nephrogenic adenoma by pathohistological examination. Case 1 was a 72-year-old female presenting with a bladder tumor 8 months after receiving ureteral tumor surgery. Transurethral resection of bladder tumor (TUR-Bt) was performed. Case 2 was a 57-year-old female who had received intravesical bacillus Calmette-Guérin (BCG) treatment 6 times after her fifth TUR-Bt. Two tumors were found by cystoscopy, and TUR-Bt was performed. There have been 39 cases of nephrogenic adenoma of the bladder reported in Japan; 21 were male and 18 female with a mean age of 56.5 years. The main complaint was hematuria, which was seen in 16 cases followed by pollakisuria in 6 cases. Nephrogenic adenoma occurred after surgery of the urinary tract in 16 cases, followed by urinary tract infection in 9 cases and intravesical BCG treatment in 6 cases. The ratio of cases occurring after intravesical BCG treatment has increased since BCG approval for bladder carcinoma treatment in December 1996 in Japan, and an increase in the number of cases is expected in the future.

Adenoma↗

PubMed2002

Significance of brain natriuretic peptides in patients on continuous ambulatory peritoneal dialysis.

It is well known that plasma brain natriuretic peptide (BNP) concentration is elevated in cardiovascular diseases such as congestive heart failure. However, although it has been reported to increase in hemodialysis (HD) patients, little is known about plasma BNP in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Plasma BNP concentrations were measured and compared among CAPD patients (n=32), HD patients (n=63) and healthy volunteers (n=14) as well as those patients without cardiovascular disease. In addition, the correlation between plasma BNP concentration and parameters of echocardiography was examined. Plasma BNP concentration was significantly higher in CAPD patients without cardiovascular disease (n=23) than in healthy volunteers (n=14) (62.1+/-60.6 pg/ml versus 9.7+/-9.7 pg/ml, mean +/- SD, P<0.0001). Furthermore, it had a positive correlation with LVMI (CAPD: r=0.37, P=0.0354; HD: r=0.49, P<0.0001) but a negative correlation with LVEF (CAPD: r=-0.39, P=0.0277; HD: r=-0.40, P=0.0010) in both CAPD and HD patients. When all patients were compared, plasma BNP concentration was significantly lower in CAPD patients (n=32) than in HD patients (n=63) (114.8+/-142.7 pg/ml versus 296.8+/-430.4 pg/ml, P<0.0001). When those patients without cardiovascular disease was compared, it was also significantly lower in CAPD patients (n=23) than in HD patients (n=40) (62.1+/-60.6 pg/ml versus 151.8+/-102.2 pg/ml, P<0.0001). In conclusion, plasma BNP concentration was elevated in CAPD patients and correlated with LVMI and LVEF, suggesting that plasma BNP in CAPD patients may be associated with left ventricular hypertrophy (LVH) and left ventricular systolic dysfunction. In addition, plasma BNP concentration was significantly lower in CAPD patients than in HD patients, suggesting that cardiac load in CAPD patients may be lower than that of HD patients.

Female↗

PubMedDate not supplied

The prognostic role of brain natriuretic peptides in hemodialysis patients.

BACKGROUND: Although plasma concentrations of brain natriuretic peptides (BNP) increase in hemodialysis (HD) patients as well as patients with cardiovascular diseases (CD), the clinical significance of BNP in HD patients has yet to be elucidated. In this study, we investigated the pathophysiological significance of BNP in HD patients. METHODS: Plasma BNP concentrations were measured in 164 HD patients after HD and 14 healthy volunteers. In 12 patients without CD, BNP was also measured before HD. Multiple regression analysis was performed to determine the important factors causing increased plasma BNP concentrations. Cardiac mortality was monitored for 36 months after baseline analysis, and the prognostic role of BNP was examined by Cox proportional hazards regression analysis. RESULTS: Plasma BNP concentrations of HD patients without CD decreased significantly during HD session (124.5 +/- 90.7 vs. 91.4 +/- 67.6 pg/ml, mean +/- SD, p = 0.004), but were still significantly higher than those of the healthy subjects (9.7 +/- 9.2 pg/ml, p = 0.0002). Plasma BNP concentrations of patients with CD were significantly higher than of those without CD (579.6 +/- 564.3 vs. 204.0 +/- 241.5 pg/ml, p < 0.0001). Plasma BNP concentrations were also significantly higher in diabetes mellitus (DM) patients than in non-DM patients (514.1 +/- 585.4 vs. 296.0 +/- 347.0 pg/ml, p = 0.0031). Multiple regression analysis showed that left ventricular mass index (LVMI), CD and DM were independent factors for the elevated BNP (R(2) = 0.303, p < 0.0001). During a 36-month follow-up period, cardiac death occurred in 13 patients. Kaplan-Meier survival estimates of patients from varying plasma BNP quartiles (<200, 200-450, 450-700 and >700 pg/ml) differed between the four groups (p < 0.0001). The group with the highest BNP level (>700 pg/ml) had the lowest survival. When compared with patients with BNP <200, the hazard ratios for cardiac death of patients with BNP of 200-450, 450-700 and >700 pg/ml were 2.3 [95% confidence interval (CI) 0.14-36.7], 18.7 (1.9-183.4) and 51.9 (6.5-416.3), respectively. The univariate Cox proportional hazards model showed that BNP, left ventricular ejection fraction, LVMI, age, DM, serum albumin and C-reactive protein (CRP) were significantly associated with the risk of cardiac mortality. By stepwise multivariate Cox proportional hazards analysis, only BNP, LVMI and CRP remained powerful independent predictors of cardiac death. The relative risk ratios were 1.002 (95% CI 1.001-1.002) for BNP, 2.192 (1.532-3.135) for CRP and 1.027 (1.013-1.042) for LVMI. CONCLUSION: High plasma BNP concentrations in HD patients were associated with volume overload, left ventricular hypertrophy, CD and DM. Plasma BNP concentration may be a useful parameter for assessing the risk of cardiac death in HD patients by providing prognostic information independently of other variables previously reported.

Cardiovascular Diseases↗

PubMedDate not supplied

Silent cerebral infarction in hemodialysis patients.

BACKGROUND: Cerebrovascular diseases are very common in hemodialysis (HD) patients. Silent cerebral infarction (SCI) has not been investigated in HD patients although it may be a significant risk factor for cerebrovascular diseases. HYPOTHESIS: Chronic renal failure may be an independent risk factor for SCI and cerebrovascular diseases. METHODS: Cranial magnetic resonance imaging (MRI) was performed on 123 HD patients without symptomatic cerebrovascular disease and on 52 control subjects. We investigated the prevalence of SCI and performed cross-sectional study using multiple logistic analysis to assess the relationship between SCI and the risk factors. RESULTS: The prevalence of SCI was significantly higher in HD patients than in the healthy control group (60 patients (48.8%) vs. 5 patients (9.6%), chi(2) = 22.4, p < 0.0001). Multiple logistic regression analysis with all subjects showed that independent risk factors of SCI were chronic renal failure, hypertension, smoking and age (R(2) = 0.468, p < 0.0001). In only the HD patient group, age and smoking were shown to be independent risk factors of SCI (R(2) = 0.378, p < 0.0001) while HD duration and hypertension were not. CONCLUSIONS: The findings of the present study indicate that chronic renal failure maintained by hemodialysis increases the prevalence of SCI and that age and smoking habits are also significantly associated with SCI in HD patients.

Age Factors↗

PubMedDate not supplied

Diagnostic localization of extra-adrenal pheochromocytoma: comparison of (123)I-MIBG imaging and (131)I-MIBG imaging.

The accurate diagnostic localization of extra-adrenal pheochromocytoma is important in the treatment of primary and metastatic tumors. In this study, we report on a case of extra-adrenal pheochromocytoma in which the tumor could not be diagnosed by 131I-metaiodobenzylguanidine (MIBG) scintigraphy but only by 123I-MIBG scintigraphy. Our patient was a 16-year old girl whose chief complaint was headaches. High levels of catecholamines were detected in the blood and urine samples. 131I-MIBG scintigraphy could not detect any abnormal accumulation, but an accumulation of 123I-MIBG was found in the pelvis. Magnetic resonance imaging (MRI) revealed a broad-based bladder tumor at the site of the accumulation. Partial cystectomy was performed, and immunohistochemical staining examination confirmed the diagnosis of extra-adrenal pheochromocytoma in the urinary bladder. In this report, we compare 131I-MIBG scintigraphy with 123I-MIBG scintigraphy and discuss their characteristics.

3-Iodobenzylguanidine↗

PubMedDate not supplied

Clinicopathological study of renal cell carcinoma.

We investigated the clinicopathological features of 153 patients with renal cell carcinoma who underwent nephrectomy at our institute from April 1992 to August 2001 and evaluated the prognostic significance of various clinical and pathological factors. The prognostic factors were statistically analyzed by the log-rank and generalized Wilcoxon tests, and for the factors that were statistically significant by both analyses, multivariate analysis was conducted by stepwise regression in the Cox proportional hazard model. As a result, the overall 1-year, 3-year, 5-year and 10-year survival rates were 93.5%, 84.3%, 82.9% and 79.1%, respectively. In addition, multivariate analysis showed that regional lymph node metastasis, stage and histological type were independent prognostic factors for renal cell carcinoma. The number of renal cell carcinoma cases incidentally discovered during routine medical check-ups has increased in recent years, and in our study, such incidental tumors accounted for 65.3% of all cases. The 5-year survival rate of incidental tumors was 87.4% as compared to that of non-incidental tumors at 70.1%, and prognosis of incidental tumors was significantly more favorable. However, even in such cases, a favorable prognosis is not necessarily guaranteed according to the presence of regional lymph node metastasis, stage and histological type. Therefore, we conclude that even in incidental tumors, if the patient has unfavorable prognostic factors, post-operative adjuvant therapy should be considered.

Adult↗