PubMed Health⌕ Search

Biomedical subjects

Yutaka Yamaguchi

Publications and source records attributed to Yutaka Yamaguchi.

At least 19 recordsLinked to original sources
PubMed2006

Effect of selenium-deficient diet on tubular epithelium in normal rats.

Selenium (Se) deficiency reduces glutathione peroxidase (GPx) activity, resulting in increased oxidative stress. We examined how Se deficiency induces renal injury via oxidative stress over time during the Se-deficient period. Seventy-two male Wistar rats were divided into two groups and fed either a control or Se-deficient diet. Rats were sacrificed on weeks 1, 2, 4, 6, 9, and 12. Blood and urine samples were collected, and the kidneys were removed. Urinalysis was performed, and creatinine clearance (Ccr) was calculated. Expressions of cellular GPx (cGPx) and phospholipid hydroperoxidase GPx (PHGPx) mRNA and GPx activity were measured. Histology was evaluated by light microscopy with immunohistochemistry for 4-hydroxy-2-nonenal (HNE) and vimentin. The Se-deficient diet caused significant decreases in GPx activity and cGPx mRNA expression but no change in PHGPx mRNA, together with significant proteinuria and glucosuria and slight decline in Ccr. The Se-deficient diet induced calcification in the kidney and increased the distribution of HNE and vimentin immunostaining in proximal tubuli, particularly around the outer medulla stripe. However, the histological damage did not progress after 6 weeks of deficiency. Se deficiency induces proteinuria and glucosuria with renal calcification, which may be primarily induced by injury of proximal tubuli via oxidative stress.

Animals↗
PubMed2006

Secondary focal segmental glomerulosclerosis following kidney transplantation in a patient with type I diabetes mellitus.

Although recurrent diabetic nephropathy is common in patients with type I diabetes after kidney transplantation, the development of focal segmental glomerulosclerosis (FGS) is rare, and its development generally takes several years. We report here a case of type I diabetes mellitus with secondary FGS accompanied by proteinuria 10 months following kidney transplantation. Episode biopsy showed secondary FGS, evidenced by glomerular capillary collapse and large epithelial cells with ballooning degeneration. Exudative dense deposition of IgM in a diffuse global mesangial pattern and enlarged glomerular diameters were observed, suggestive of glomerular hyperfiltration which can lead to secondary FGS. An imbalance in body size between donor and recipient and/or uncontrolled diabetes are potential causes of glomerular hyperfiltration. We administered angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker to reduce hyperfiltration-induced renal damage; the combination therapy reduced proteinuria from 2346 to 258 mg/d. Secondary FGS should be a consideration after kidney transplantation in patients with type I diabetes mellitus.

Adult↗
PubMed2006

Early and late histopathological changes in renal allografts procured by laparoscopic donor nephrectomy.

INTRODUCTION: Subcapsular cortical damage (SCCD) is a characteristic pathological change, which is seen in renal allograft biopsy specimen obtained immediately after laparoscopic donor nephrectomy (LDN). In this study we evaluated the early and late histopathological effect of SCCD examining renal allograft biopsy specimens obtained after kidney transplantation. MATERIALS AND METHODS: Laparoscopic donor nephrectomy was performed on 250 donors between July 2000 and September 2004 in our institution. Allograft biopsy of all 250 kidneys was performed immediately after LDN (zero hour biopsy). Of 250 biopsy specimens, 105 were diagnosed as SCCD and the allograft biopsy specimens obtained from 105 recipients after transplantation were enrolled in this study. All specimens were routinely examined by using light microscopy and immunofluorescence. RESULTS: In 87 patients 256 allograft biopsy specimens did not show post-pathological changes of SCCD. Twenty biopsy specimens obtained from 18 recipients showed tubular necrosis and a partly tubular regeneration and patchy interstitial hemorrhage, which seemed to be caused by SCCD. Ten allograft biopsy specimens from nine recipients demonstrated residual pathologic changes in SCCD early after transplantation. The other 10 specimens from nine recipients had abnormal histopathologic changes including interstitial edema and fibrosis, tubular atrophy and glomerular sclerosis in the subcapsular cortex late after transplantation. CONCLUSION: The early change of SCCD after transplantation remained intact and partial regeneration and the late showed subcapsular fibrosis with glomerular sclerosis. The incidence of the subcapsular lesions due to SCCD after transplantation was 17% in 105 allografts.

Biopsy↗
PubMed2006

Early recurrence of lupus nephritis after renal transplantation--a case report.

The risk of recurrent lupus nephritis (LN) in renal transplant recipients with systemic lupus erythematosus (SLE) used to be rare (1-4%). However, recent studies have suggested a higher rate of recurrence in SLE patients after renal transplantation (up to 30%). The interval from transplantation to recurrence of LN has been reported to vary from five days to eight years. We report here a renal transplant recipient with SLE who had recurrent LN 10 d after transplantation.

Adult↗
PubMed2006

Early recurrence of dense deposit disease with marked endocapillary proliferation after renal transplantation.

Dense deposit disease (DDD), also known as type II membranoproliferative glomerulonephritis (MPGN), is characterized by the presence of continuous intramembranous dense deposits. At present, the histogenesis of DDD is not well known. Reported herein are two cases of early recurrence of DDD in renal allografts, with marked endocapillary proliferation. In case 1 the first allograft biopsy revealed electron-dense deposits mainly in the subendothelial and mesangial areas along with subepithelial humps, but a continuous intramembranous deposition was not obvious. In the sequential biopsy, the deposits were more often seen in the intramembranous area and finally formed a continuous osmiophilic substance, which is a characteristic feature of DDD. In case 2, continuous intramembranous deposition already coexisted with endocapillary proliferation at the first biopsy. In both cases, endocapillary proliferation was alleviated slightly as time progressed. The present report suggests that endocapillary proliferative glomerulonephritis is the earliest lesion in some cases of DDD. Detailed review of a clinical history and a subsequent follow-up biopsy should be done to distinguish these lesions from other types of endocapillary proliferative glomerulonephritis.

Adolescent↗
PubMed2006

Degradation of cyanuric acid in soil by Pseudomonas sp. NRRL B-12227 using bioremediation with self-immobilization system.

The rates of degradation of cyanuric acid, a key intermediate in a metabolic pathway of s-triazine herbicides, were measured for Pseudomonas sp. NRRL B-12227. The rate of degradation was affected by the rate of cyanuric acid transport through cell membranes and the activity of cyanuric acid amidohydrolase inside the cells. At low concentrations of cyanuric acid, the acclimation of cells to cyanuric acid and/or added nutrients effectively enhanced the degradation rate. The strain was also applied to bioremediation using a Bioremediation with Self-Immobilization System (BSIS), in which Pseudomonas sp. NRRL B-12227 cells were co-immobilized with Bacillus subtilis, the latter of which secretes a viscous polymer, in a shallow layer of soil packed in a column. More than 70% of the Pseudomonas sp. NRRL B-12227 cells were co-immobilized with the B. subtilis in a 7.5 cm layer of the packed soil by self-aggregation. More than 60% of the 1 mM cyanuric acid supplied to the packed soil was degraded in this layer during a 72 h period.

Biodegradation, Environmental↗
PubMed2005

A case of acute humoral rejection with various depositions of C4d, IgG, IgM, and C3c in peritubular capillaries and/or glomerular capillaries.

A 41-year-old Japanese male patient with end-stage renal disease received ABO compatible living related kidney transplantation from his sister on April 2003. The kidney functioned immediately after kidney transplantation. Protocol allograft biopsy at 1 yr after kidney transplantation was performed on April 2004. His serological data was not particular and he did not suffer with chronic inflammation. The allograft biopsy specimen revealed moderate accumulations of polymorphonuclear leukocytes in peritubular capillaries (PTCs), dilatation of PTCs and moderate infiltrations of polymorphonuclear and/or mononuclear cell in glomeruli (Transplant glomerulitis, moderate). Immunofluorescent study (IF) of a frozen section of the allograft biopsy specimen showed a strong, diffusely distributed endothelial-staining pattern in PTCs for C4d. The C4d was also strongly detected in a linear glomerular basement membrane (GBM) pattern. And widespread moderate C3c deposits, weak IgM, and IgG deposits were also seen in PTCs. Immunofluorescent study also showed granularly peripheral and mesangial deposits of strong IgM, C1q, and moderate IgG in glomeruli, IgA and C3c were faintly positive. The panel reactive antibody, which had been negative before transplantation, was positive for both HLA classes I and II at that time. We diagnosed as acute humoral rejection (AHR) and he was treated with course of steroid pulses and 5 d of gusperimus (DSG); and a total of three times Plasma exchange (PE) treatment was added. The level of serum creatinine, once increased to 1.7 mg/dL, decreased gradually to 1.4 mg/dL. He has a stable graft function. This is the only case of various depositions of immunoglobulins and complements in PTC and/or glomerular capillaries during AHR.

Acute Disease↗
PubMed2005

Peritubular capillaritis in early renal allograft is associated with the development of chronic rejection and chronic allograft nephropathy.

Peritubular capillaritis (PTCitis) has been recognized as one form of acute/active allograft rejection, and its relation to humoral immunity has been suggested. However, its mechanisms remain to be fully clarified, and there are no criteria for evaluating the extent of PTCitis in a biopsied allograft. In this study, we first evaluated the extent of PTCitis in early allografts in patients presenting with acute cellular rejection (ACR) and antibody-mediated rejection (AbAR). We also included patients who showed no evidence of ACR and/or AbAR. Next, we investigated whether or not PTCitis persisted and if peritubular capillary basement membrane (PTCBM) thickening was present in their follow-up biopsy specimens. We adopted the scoring system of PTCitis, which was presented at the Seventh Banff Conference on Allograft Pathology in 2003. In total, 53 patients were included in this study. At first biopsy, 17 showed ACR, eight showed AbAR, 16 showed mild PTCitis only, and 14 were without significant pathologic changes. The PTC score was the highest in the AbAR group, and in some patients the score gradually increased during the follow-up period. Similar changes were also observed in the group with mild PTCitis only. In late allografts, half of the patients with AbAR developed chronic rejection (CR), and the PTCBM score was the highest in that group. Surprisingly, CR was present in more than 30% of patients without ACR and/or AbAR but mild PTCitis only. In the control group, only a few showed CR and/or chronic allograft nephropathy (CAN). In conclusion, it became clear that we should carefully monitor for mild PTCitis in early allografts. In addition, our data also proved the usefulness of the PTC score and PTCBM score.

Acute Disease↗
PubMed2005

Long-term course of post-transplant mesangial IgA deposition: clinicopathologic study of nine cases.

We conducted the present study to elucidate the fate of post-transplant mesangial IgA deposit under the long-term observation. Out of a total of 45 cases with post-transplant mesangial IgA deposition, nine cases with more than 4 yr of follow-up term were enrolled in this study, and clinicopathologic characteristics were described. The study included three men and six women with a mean age of 34.2 yr. The average observation time from the detection of mesangial IgA deposition was 6.1 yr. Three cases were categorized as recurrent IgA nephropathy, while six cases were classified into latent mesangial IgA deposition. One case with hypertension developed end-stage renal disease. The significant improvement in microscopic hematuria was observed in one recurrent IgA nephropathy case. Microscopic findings included mild mesangial stalk thickening in all but one case. IgA deposition demonstrated a significant decrease in three latent mesangial IgA deposition cases. No apparent reduction in dense deposit quantity was observed on electron microscopy. There was no association between clinicopathologic findings and the regimen of anti-immunosuppressive agents. This study showed the improvement of the disease activity did occur in both recurrent IgA nephropathy and latent mesangial IgA deposition. Further investigation of latent mesangial IgA deposition may present the important clue to the pathogenesis of IgA nephropathy.

Adult↗
PubMed2005

Latent IgA deposition from donor kidney is the major risk factor for recurrent IgA nephropathy in renal transplantation.

BACKGROUND: Previous studies have recognized risk factors for recurrent IgA nephropathy (r-IgAN) in renal transplantation. However the clinical significance of latent IgA deposition from the donor kidney remains to be determined. PATIENTS AND METHODS: Between 1992 and 1999, 0-hour allograft biopsies were performed in 510 renal transplantation recipients at the Kidney Center of Tokyo Women's Medical University. Among these 510 patients, there were 49 whose primary disease was identified as IgAN. Among these 49 patients, 13 patients (26.5%) were diagnosed as having r-IgAN based on renal biopsy. We compared risk factors of r-IgAN, including IgA deposition, between the r-IgAN and non-r-IgAN groups. RESULTS: We assessed factors previously reported to be risk factors for r-IgAN, such as follow-up period after transplantation, sex, ages of donors and recipients, donor type, ABO compatible or incompatible transplantation, number of HLA-A, B, and DR mismatches, number of donors with HLA-A2, B35, B46, and/or DR4, duration to end stage renal disease, duration of dialysis, and latent IgA deposition from donor kidneys. Latent IgA deposition was the only risk factor that differed significantly in frequency between patients with and without recurrence (38.5% in r-IgAN group vs. 9.1% in non-r-IgAN group, p = 0.037). Other factors did not differ significantly between the two groups. Clinical factors, such as urinary protein excretion, urinary red blood cell sediment and serum creatinine, were significantly worse and the number of patients who required hemodialysis 5 yr after transplantation was significantly higher in the r-IgAN group than in the non-r-IgAN group (38.5 vs. 5.6%, p = 0.001). Four of the five patients who required hemodialysis in the r-IgAN group had latent IgA deposition from the donor kidney. CONCLUSION: Our data suggest that 26.5% out of patients with primary IgAN will develop recurrence within 5 yr after transplantation. Latent IgA deposition from the donor kidney was one of the risk factors of r-IgAN and it would lead to the development of r-IgAN. Moreover, r-IgAN will compromise graft survival, especially in cases with latent IgA deposition from the donor kidney.

Adolescent↗
PubMed2004

A case of renal sarcoidosis: a special reference to calcium metabolism as a diagnostic and the therapeutic implications.

Sarcoidosis is a systemic granulomatous disease of unknown etiology and is associated with a wide variety of renal disorders including nephrolithiasis, hypercalciuria, hypercalcemia, nephrocalcinosis, tubular defect, glomerulonephritis, and granulomatous interstitial nephritis. We report a case of renal sarcoidosis in which we could not detect any evidence of extrarenal involvements that was diagnosed by renal biopsy and abnormal calcium metabolism incompatible with chronic renal insufficiency. On laboratory findings, decreased creatinine clearance, proteinuria, hypercalcemia, hypercalciuria, and mildly elevated serum angiotensin-converting enzyme (ACE) were seen. Serum intact parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (1,alpha-25 vit D) were lower and higher than normal range, respectively, whereas the patient was already in chronic renal insufficiency. He was treated with oral corticosteroid. Serum ACE tended to fall, and 1,alpha-25 vit D level decreased with substantial fall of serum calcium and daily calcium excretion. In contrast, intact PTH increased slowly in accordance with a fall of serum calcium compatible with the level of renal impairment. Creatinine clearance and daily excretion of protein improved. The case reported here may propose that serial measurement of serum level of 1,alpha-25 vit D, calcium level, and magnitude of daily calcium excretion into urine is a simple and meaningful tool to detect the therapeutic response in sarcoidosis with abnormal calcium metabolism.

Anti-Inflammatory Agents↗
PubMed2004

[The clinical efficacy of Bladder Chek NMP22 in urothelial cancer].

The purpose of this study is to investigate the clinical efficacy of a quick test for NMP22 (Nuclear Matrix Protein 22), Bladder Chek NMP22, as a screening test for urothelial cancers. The subjects include 51 cases(43 cases with pathologically confirmed bladder cancer, and 8 cases with upper urothelial cancer). Bladder Chek NMP22 revealed false positive in the urine with more than 1 x 10(5)/microliter of erythrocytes and 1 x 10(3)/microliter of white blood cells. Thus, showing that Bladder Chek NMP22 was not relatively affected by the contaminated erythrocytes and white blood cells, compared with other conventional methods to detect urinary malignant disease. In 51 cases diagnosed of having pathologically urothelial cancers, the sensitivity of Bladder Chek NMP22 was 56.8%. Bladder Chek NMP22 demonstrated more excellent sensitivity than the other methods. The positivity of Grade3 patients was 68.4%, 68.4% and 63.2% by Bladder Chek NMP22, NMP22 ELISA and urinary cytology. In contrast, the positivity rate for the patients with Grade1 stage was 58.3%, 33.3% and 8.3%. There is no significance of positivity rate between each examination in patients with high grade cancer. However Bladder Chek NMP22 demonstrated the higher positivity in patients with low grade cancer. Bladder Chek NMP22 test could be an easy and confidential method to detect urothelial cancers, especially with low grade, as a screening examination.

Biomarkers, Tumor↗
PubMed2003

Histological features of renal allograft biopsies in ABO minor-mismatched kidney transplantation.

We examined histological features of allograft biopsies in ABO minor-mismatched kidney transplantation. Forty-five patients who underwent ABO minor-mismatched kidney transplantation between September 1999 and December 2001 at our institute. The mean age was 32.6 years, with 28 males and 17 females. We divided them into five groups based on the donor and recipient ABO blood groups. Group 1, O renal allografts given to A patients (13 patients); Group 2, O to B (9), Group 3, O to AB (2); Group 4, A to AB (9); and Group 5, B to AB (12). From September 1999 to April 2002, we performed 127 allograft biopsies in these 45 ABO minor-mismatched kidney transplant recipients. Among a total of 127 biopsy specimens, 47 specimens were taken as 0- or 1-h biopsies and 6 were protocol biopsies. Pathological analysis of 74 episode biopsy specimens showed: acute humoral rejection (AHR) in 13 (18%); acute cellular rejection (ACR) in 17 (23%); combined AHR and ACR in eight (11%); borderline change in six (8%); chronic rejection in 10 (12%); cyclosporin or tacrolimus nephrotoxicity in seven (10%) and chronic allograft nephropathy in three (4%). In total, some form of acute rejection (AR) was seen histologically in 38 biopsy specimens (48%) from 19 patients (42%). When we investigated AR in two separate categories, i.e. AHR and ACR, AHR was diagnosed in 21 biopsy specimens (26%) from 15 patients (33%) and ACR was seen in 25 biopsy specimens (31%) from 13 patients (29%). We compared the incidence rate of acute rejection in the cases of ABO minor-mismatched renal transplantation with ABO-incompatible and ABO-compatible cases between January 1989 and December 1999. The incidence rate of AR in ABO minor-mismatched cases (42%) was statistically lower than that in ABO-incompatible cases (63%). There was no statistical difference in the incidence rate of AR between ABO minor-mismatched cases and ABO-compatible cases (49%). There was statistical difference in the incidence of AR among the donor and recipient ABO blood groups. Group 4 (A allografts given to AB patients) had the statistically highest rate of AR (89%), followed by Group 1 (54%), Group 5 (33%) and Group 2 (11%), and there was no AR case in Group 3 (O to AB). In conclusion, the incidence rate of AR in ABO minor-mismatched kidney transplantation is statistically lower than ABO-incompatible cases and is not statistically different from that in ABO-compatible cases. The incidence cases of AHR are slightly higher than that of ACR in ABO minor-mismatched kidney transplantation and this finding is similar to findings of ABO incompatible kidney transplantation. Finally, there is a statistical difference in AR incidence among the donor and recipient ABO blood groups.

ABO Blood-Group System↗
PubMed2003

Histological evaluation of renal allograft protocol biopsies in the early period and 1 year after transplantation.

We histologically evaluated protocol biopsy specimens of renal allografts obtained in the early period and 1 year after transplantation. The patients were divided into those with at least one history of acute rejection (AR group) and no history of rejection (NAR group), and the histopathological features in the two groups were compared. A total of 45 early protocol biopsy specimens were obtained from 40 patients, and 31 1-year biopsy specimens were obtained from 30 patients. Acute rejection (AR) or borderline change was observed in the early protocol biopsy specimens from 19 (45.2%) cases. AR or borderline change was observed in 12 of 19 (63.2%) in the AR group, and in 7/26 cases (26.9%) in the NAR group. The incidence of AR or borderline change in the AR group was higher than in the NAR group. Toxic tubulopathy was found in the early protocol biopsy in 16 cases (35.6%). The 1-year biopsies tended to reveal more complicated findings. Chronic rejection (CR) was seen in 8/16 cases (50.0%) in the AR group, and it was more frequent than NAR group (two cases, 13.3%). In conclusion, the incidences of both AR and CR were higher in the cases with a previous episode of AR. The early protocol biopsy was useful in screening for subclinical AR and toxic tubulopathy. The 1-year biopsy was useful for evaluating various types of chronic graft damage. We expect that adequate treatment based on protocol biopsy findings in each patient will lead to better graft survival.

Adolescent↗
PubMed2003

C4d deposition in peritubular capillary and alloantibody in the allografted kidney suffering severe acute rejection.

BACKGROUND: Alloantibodies and C4d deposition in peritubular capillaries (PTCs) are thought to be related to antibody-mediated acute rejection. The purpose of this study was to evaluate the relationship between C4d deposition in PTCs and alloantibodies at various days after allograft dysfunction due to severe acute rejection. METHOD: There were 620 renal transplantations (Tx) performed. Forty patients diagnosed with acute humoral and/or vascular rejection showed graft dysfunction with anuria or dysuria. The patients were divided into four groups by ABO compatibility and clinical course after graft dysfunction: compatible recipients with graft loss (c-GL; n = 6); compatible recipients with recovery from graft dysfunction (c-RE; n = 10); incompatible recipients with graft loss (i-GL; n = 9); and incompatible recipients with recovery from graft dysfunction (i-RE; n = 15). RESULTS: C4d depositions in 4/6 c-GL recipients increased, and those in 8/10 c-RE recipients decreased after graft dysfunction. These changes in C4d deposition between the c-GL and the c-RE groups were significantly different (P < 0.01). These titres of anti-A/B IgG antibody in 7/9 i-GL recipients increased and those in 8/15 i-RE recipients decreased after graft dysfunction. These changes in titre between the i-GL and the i-RE groups were significantly different (P < 0.01). All c-GL recipients and 4/10 c-RE recipients had anti-HLA antibody at the last biopsy. There was a significant difference in the number of recipients who had anti-HLA antibody between the c-GL and the c-RE groups (P < 0.05). CONCLUSIONS: These results indicate that changes in C4d deposition in PTCs in the c-ABO group and titre of anti-A/B IgG antibody in the ABO-incompatible groups exert a strong impact on graft survival after dysfunction in the early period after Tx.

ABO Blood-Group System↗