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Biomedical subjects

Hitoshi Yokoyama

Publications and source records attributed to Hitoshi Yokoyama.

At least 37 records · Page 2Linked to original sources
PubMed2005

Macular abnormalities and optic disk anomaly associated with a new PAX2 missense mutation.

PURPOSE: To report a family with macular abnormalities accompanied by anomalies of the optic disk and kidney associated with a new PAX2 missense mutation. DESIGN: Observational case report. METHODS: A 34-year-old female presented with horizontal nystagmus, poor visual acuity, and chronic renal failure. She had bilateral colobomatous disk anomaly and foveal hypoplasia. Her mother also had renal dysfunction and bilaterally impaired vision. Besides the optic disk dysplasia, the fovea was hypoplastic in the right eye, whereas pigmented macular atrophy was observed in the left eye. The entire coding regions of PAX2 and PAX6 were screened for mutations. RESULTS: A heterozygous mutation G755C in exon 2 of PAX2 that results in a missense mutation, R71T, was identified in the proband and her mother. No mutations were detected in PAX6. CONCLUSIONS: A new PAX2 missense mutation, R71T, may cause macular abnormalities in addition to anomalies of the optic disk and the kidney.

Abnormalities, Multiple↗
PubMed2005

Involvement of extracellular signal-regulated kinase and p38 in human diabetic nephropathy.

BACKGROUND: The involvement of mitogen-activated protein kinase (MAPK) in human diabetic nephropathy has not been fully investigated. METHODS: The presence of cells positive for the phosphorylated MAPK family (phosphorylated extracellular signal-regulated kinase [p-ERK], phosphorylated p38MAPK [p-p38MAPK]) was investigated immunohistochemically in kidneys of 30 patients with diabetic nephropathy. In addition, 10 patients with minimal change nephrotic syndrome, 10 patients with thin basement membrane disease, and 5 patients with benign nephrosclerosis were studied as disease controls. The presence of activated nuclear factor-kappaB (p65)-positive cells also was evaluated in kidney specimens. RESULTS: In patients with diabetic nephropathy, p-ERK, p-p38MAPK, and p65 were observed in mesangial cells, endothelial cells, podocytes, tubular epithelial cells, and mononuclear infiltrates in interstitium. Numbers of p-ERK-, p-p38MAPK-, and p65-positive cells in both glomeruli and interstitium in patients with diabetic nephropathy were higher than those in controls. In particular, the number of glomerular p-ERK-positive cells in patients with diabetic nephropathy increased in accordance with the progression of glomerular lesions and correlated well with the number of glomerular p65-positive cells (r = 0.654; P < 0.01; n = 30). Conversely, the number of p-p38MAPK-positive cells in glomeruli did not correlate with glomerular lesions. However, the number of tubulointerstitial p-p38MAPK-positive cells in patients with diabetic nephropathy reflected the severity of tubulointerstitial lesions, and numbers of those in the interstitium increased with good correlation to numbers of tubulointerstitial p65-positive cells (r = 0.757; P < 0.01; n = 30) and interstitial CD68-positive macrophages (r = 0.647; P < 0.05; n = 30) and urinary monocyte chemoattractant protein-1 levels (r = 0.605; P < 0.05; n = 30). CONCLUSION: These results suggest that MAPK phosphorylation contributes to human diabetic nephropathy. In particular, ERK and p38MAPK may be distinctly involved in glomerular and tubulointerstitial lesions in human diabetic nephropathy.

Antigens, CD↗
PubMed2005

Glomerular proteinuria induces heme oxygenase-1 gene expression within renal epithelial cells.

To clarify the patterns of heme oxygenase-1 (HO-1) production within the human kidney, we examined HO-1 mRNA expression in various renal diseases and compared the patterns with those of HO-1 protein expression and these data with the clinical features. The degrees of hematuria and proteinuria and the levels of urinary N-acetyl-beta-D-glucosaminidase (NAG), beta(2)-microglobulin (beta(2)-mg), and creatinine were determined. In situ hybridization and immunohistochemical studies were performed to evaluate HO-1 expression. HO-1 mRNA was detectable within tubular, glomerular, and Bowman's epithelial cells and infiltrating macrophages. Within the proximal tubuli, there was a correlation between expression of HO-1 protein and mRNA, but the intensity of HO-1 mRNA expression was much less than expected from the levels of protein. In contrast, both HO-1 protein and mRNA were expressed at significant levels within distal tubuli. Furthermore, there was no correlation with both expressions within distal tubuli. HO-1 mRNA expression within tubular, glomerular, and Bowman's epithelial cells tended to be more intense with greater degrees of proteinuria. However, there was little correlation between the intensity of HO-1 mRNA expression and the degree of hematuria, NAG, and beta(2)-mg. HO-1 plays important roles in maintaining renal functions by protecting renal epithelial cells from glomerular proteinuria, which can become a cause of oxidative stress. Furthermore, from the different expression pattern of HO-1 gene between within the proximal tubuli and within the distal tubuli, renal expression of HO-1 is regulated in a segment-specific manner, with HO-1 thereby playing distinct roles in different segments of the nephron to maintain renal functions.

Acetylglucosaminidase↗
PubMed2005

[Preoperative evaluation and management of patients with ischemic heart disease undergoing noncardiac surgery].

The evaluation and management of patients with coronary artery disease (CAD) undergoing noncardiac surgery are becoming important medical issues in modern society with the aging of the population and prevalence of CAD. For patients with CAD, medical therapy (beta-blockers, statins), percutaneous coronary artery intervention (PCI) with/without stenting, and coronary artery bypass grafting have been the modalities for management. Although balloon angioplasty is effective in selected patients, bare-metal stents (BMS) require post-PCI antiplatelet therapy for 4-6 weeks delaying noncardiac procedures As recently reported patients with drug-eluting stents (DES) experienced late stentthrombosis due to discontinuation of antiplatelet therapy in the long-term period before noncardiac surgery, suggesting the need for life-long anticoagulant therapy after DES placement. Recently, offpump coronary artery bypass (OPCAB) has become a safe and effective procedure for direct coronary revascularization. OPCAB, without cardiopulmonary bypass and its adverse effects, can be performed simultaneously with noncardiac surgery such as carotid endoarterectomy, abdominal aortic aneurysm resection, and peripheral arterial reconstruction. OPCAB is a promising option as a simultaneous or staged procedure for patients with CAD and noncardiac disease.

Adrenergic beta-Antagonists↗
PubMed2005

[Evaluation of neurosonography for a case of brainstem transient ischemic attack (TIA) due to proximal subclavian artery stenosis, with favorable outcome after axillo-axillary bypass grafting].

We report an 82-year-old man with crescendo brainstem TIA and left upper-limb ischemia due to the left proximal subclavian artery stenosis. Angiography revealed that the left proximal subclavian artery was stenotic. The right vertebral artery was considered to be aplastic or occlusive. Neurosonography, especially the echo-Doppler study of the left vertebral artery, showed that the subclavian artery steal phenomenon did not occur. This study has enabled us to opt for axillo-axillary bypass. We preferred to avoid percutaneous transluminal angioplasty in order to avoid the risk of embolization. The patient received the axillo-axillary bypass operation. He has been free of TIAs and the left upper-limb ischemia since the surgery. We have evaluated his blood circulation fully, by comparing his state before and after the axillo-axillary bypass grafting.

Aged↗
PubMed2005

Scintigraphic assessment of the effects of bone marrow-derived mononuclear cell transplantation combined with off-pump coronary artery bypass surgery in patients with ischemic heart disease.

UNLABELLED: Myocardial SPECT may be useful for assessment of the therapeutic effects and the mechanisms of cardiac regeneration medicine. We aimed to assess first the feasibility and the short-term safety of autologous bone marrow-derived mononuclear cell transplantation (BMCT) into the ischemic myocardium in patients who undergo off-pump coronary artery bypass surgery (OPCAB). In addition, we aimed to assess our hypothesis that the BMCT may help ameliorate myocardial perfusion in patients with ischemic heart disease (IHD) using myocardial perfusion scintigraphy. METHODS: We performed BMCT in 10 patients with IHD during OPCAB. Cells for BMCT were collected by intraoperative bone marrow aspiration or by preoperative cellular apheresis after pretreatment with granulocyte colony-stimulating factor. After OPCAB was performed in all graftable ischemic areas, a total of 3.4 +/- 1.2 x 10(9) mononuclear cells, including 5.2 +/- 1.6 x 10(6) CD34-positive (CD34(+)) cells, were injected into ungraftable ischemic myocardial areas. Dipyridamole-stress and resting (99m)Tc myocardial SPECT was performed before and 1 mo after the procedures. RESULTS: BMCT was performed safely in all patients. Compared with before treatment, myocardial (99m)Tc tracer uptake on the dipyridamole-stress image increased similarly in BMCT- and OPCAB-treated areas, whereas tracer accumulation at rest did not change in all myocardial areas. The improvement of myocardial perfusion was not correlated with the total number of mononuclear cells transplanted. However, it was positively correlated with the number of transplanted CD34(+) cells: (99m)Tc tracer uptake after/before BMCT (ratio) = 1.091 x (CD34(+) cell number [x10(6)])(0.074) (r(2) = 0.48, P < 0.05), although new development of coronary vessels was not documented cineangiographically. Myocardial histopathology in 2 of 3 autopsy cases revealed coronary angiogenesis in the areas corresponding to the sites of BMCT. CONCLUSION: The present study demonstrates the feasibility of BMCT combined with OPCAB. This therapy improves myocardial perfusion possibly via CD34-related development of coronary microvessels.

Adult↗
PubMed2004

Blockade of CCR2 ameliorates progressive fibrosis in kidney.

Fibrosis is a hallmark of progressive organ diseases. Monocyte chemoattractant protein (MCP)-1, also termed as macrophage chemotactic and activating factor (MCAF/CCL2) and its receptor, CCR2 are presumed to contribute to progressive fibrosis. However, the therapeutic efficacy of MCP-1/CCR2 blockade in progressive fibrosis remains to be investigated. We hypothesized that blockade of CCR2 may lead to the improvement of fibrosis. To achieve this goal, we investigated renal interstitial fibrosis induced by a unilateral ureteral obstruction in CCR2 gene-targeted mice and mice treated with propagermanium or RS-504393, CCR2 inhibitors. Cell infiltrations, most of which were F4/80-positive, were reduced in CCR2 knockout mice. In addition, dual staining revealed that CCR2-positive cells were mainly F4/80-positive macrophages. Importantly, CCR2 blockade reduced renal interstitial fibrosis relative to wild-type mice. Concomitantly, renal transcripts and protein of MCP-1, transforming growth factor-beta, and type I collagen were decreased in CCR2-null mice. Further, this CCR2-dependent loop for renal fibrosis was confirmed by treatment with CCR2 antagonists in a unilateral ureteral obstruction model. These findings suggest that the therapeutic strategy of blocking CCR2 may prove beneficial for progressive fibrosis via the decrease in infiltration and activation of macrophages in the diseased kidneys.

Animals↗
PubMed2004

A simple technique of introducing intracoronary shunts for off-pump coronary artery bypass surgery.

We describe a simple technique of introducing intracoronary shunts for off-pump coronary artery bypass. This technique, with an aid of micro-bulldog clamp, provides both a test clamp with ischemic preconditioning effect, and a quick and easy introduction of intracoronary shunt, giving a clear visualization of coronary anastomosis site and distal coronary artery perfusion. We recommend this technique as another effective modality in off-pump coronary artery bypass surgery.

Anastomosis, Surgical↗
PubMed2004

Shunt nephritis with positive titers for ANCA specific for proteinase 3.

The authors report a case of shunt nephritis with antineutrophil cytoplasmic autoantibody (ANCA) and review 2 similar cases. A 55-year-old man was admitted to our hospital for continuous fever and foot edema in 2002. A ventriculoperitoneal shunt was implanted because of a brain abscess and subsequent hydrocephalus in 1987; it was changed to a ventriculoatrial (VA) shunt in 1995. Urinary analysis showed proteinuria (5.4 g/d) and microscopic hematuria. Laboratory data showed renal dysfunction and hypocomplementemia. ANCA specific for proteinase 3 (PR3-ANCA) was positive in his serum, and blood culture grew Propionibacterium acnes. Renal biopsy results showed membranoproliferative glomerulonephritis type I. Therefore, the VA shunt was replaced, and antibiotics were administered. Oral prednisolone was initiated at a dose of 50 mg/d. Proteinuria and the serum levels of creatinine were improved concomitant with normalization of the serum complement levels and the decrease in serum PR3-ANCA titer. Similarly, another 2 cases reported in the literature of PR3-ANCA-positive shunt nephritis caused by P acnes and Gemella morbillorum showed good outcomes after removal of the shunt and administration of antibiotics with or without steroid therapy.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2004

Gene therapy via blockade of monocyte chemoattractant protein-1 for renal fibrosis.

Monocyte chemoattractant protein (MCP)-1, also termed monocyte chemotactic and activating factor (MCAF)/CCL2, plays an important role in progressive organ fibrosis. It was hypothesized that MCP-1, through its cognate receptor, CCR2, regulates the pathogenesis and is therapeutically of importance for renal fibrosis. To achieve this goal, the therapeutic efficacy and efficiency in renal fibrosis induced by a unilateral ureteral obstruction nephropathy model in mice by the blockade of MCP-1/CCR2 signaling was studied. The delivery of N-terminal deletion mutant of the human MCP-1 gene, 7ND, into a skeletal muscle ameliorated renal fibrosis by resulting in decrease in the deposit of type I collagen and in reduced expression of TGF-beta. Concomitantly, gene transfer of 7ND reduced the cell infiltration, most of which were CCR2-positive macrophages, followed by the decrease in MCP-1 expression in the diseased kidneys. These observations suggest that MCP-1 through CCR2 signaling is responsible for Mphi recruitment, which augments downstream events, resulting in renal fibrosis. Moreover, these findings imply that gene therapy against MCP-1/CCR2 signaling via the mutant gene transferred strategy may serve a beneficial therapeutic application for renal fibrosis.

Animals↗
PubMed2004

Resection of local recurrence of renal cell carcinoma in a hemodialysis patient 6 years after radical nephrectomy.

Left radical nephrectomy was performed on a 39-year-old-man because of renal cell carcinoma (grade 1, clear cell and granular cell carcinoma: pT3b pN0 pM0), 6 years after the beginning of hemodialysis. The second surgical intervention for local recurrence was performed 6 years after the first operation (grade 2 > 3, clear cell and granular cell carcinoma). This is the second published case report of the resection of a local recurrence of renal cell carcinoma after nephrectomy in a hemodialysis patient. Even after the curative operation, follow up for local recurrence should be continued in hemodialysis patients, especially for high stage renal cell carcinoma.

Adult↗
PubMed2004

Pathologic findings of initial biopsies reflect the outcomes of membranous nephropathy.

BACKGROUND: A considerable diversity of prognosis is seen with idiopathic membranous nephropathy (IMN). The initial factors affecting long-term outcome remain unclear. METHODS: We studied retrospectively 105 patients with IMN who had been followed up for at least 5 years, or until end-stage renal failure (ESRF) (primary outcome), or death (secondary outcome). We analyzed the initial clinicopathologic factors affecting primary and secondary outcomes. We assigned the patients to two groups and one subgroup, based on the electron microscopic findings. The groupings were: homogeneous type with synchronous electron dense deposits; homogeneous type with large dense deposits (deep subgroup); and heterogeneous type with various phases of dense deposits. RESULTS: No differences in the initial clinicopathologic states were seen between the homogeneous (N= 60) and heterogeneous types (N= 45), apart from hypertension and disease history before biopsy. In the homogeneous type, only one patient developed ESRF, which was drug-induced, and remission occurred earlier than in the heterogeneous type. With regard to secondary outcomes, increased age, male gender, heterogeneous type, and deep subgroup were independent risk factors. There were no significant differences attributable to therapeutic regime with respect to primary or secondary outcome in either group. CONCLUSION: Our results indicate that an electron microscopic classification, at initial biopsy, as heterogeneous type or deep subgroup type with dense deposits are independent indicators of poor prognosis in IMN.

Adolescent↗
PubMed2004

Prognosis and risk factors for idiopathic membranous nephropathy with nephrotic syndrome in Japan.

BACKGROUND: Idiopathic membranous nephropathy (IMN) is a representative form of refractory nephrotic syndrome in Japan. Although IMN is thought to run a more benign course in Japanese than in the Caucasian population, risk factors and appropriate treatment are controversial issues. METHODS: The research group supported by a grant for "Progressive Renal Disease" from the Ministry of Health, Labor and Welfare, Japan, carried out a national survey of patients with IMN and nephrotic syndrome. Of 1066 nephrotic patients with histopathologically proven IMN registered from 1975 to 1993 in 85 institutions, 949 patients were studied. RESULTS: The overall renal survival rates were 95.8%, 90.3%, 81.1%, and 60.5% at 5, 10, 15, and 20 years after diagnosis, respectively. When clinical and histopathologic features at onset of nephrotic syndrome were evaluated by multivariate analysis, male gender, old age (> or =60 years), high serum creatinine concentration (> or =1.5 mg/dL), and the development of tubulointerstitial lesions (> or =20% of the biopsy sample area) were significant predictors of progression to end-stage renal disease (ESRD). The renal survival rate in patients on steroid therapy was significantly higher than in patients on supportive therapy alone. Patients achieving a remission showed a significant reduction of risk for progression. CONCLUSION: IMN is a disease with a comparatively good prognosis in Japan even when it is associated with nephrotic syndrome. Steroid therapy, which has not been recommended for IMN in most review articles, seems to be useful at least for Japanese patients. In particular, a remission from heavy proteinuria likely results in a favorable outcome.

Adult↗
PubMed2004

The outcome and a new ISN/RPS 2003 classification of lupus nephritis in Japanese.

BACKGROUND: A considerable diversity in prognosis is seen with lupus glomerulonephritis (LGN). Hence, the clinical usefulness of a recent International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003 classification to judge the long-term outcome of human LGN has been investigated. METHODS: We studied retrospectively 60 subjects with LGN (7 males, 53 females, mean age of 33 years old) who underwent renal biopsies and were followed from 1 to 366 months, with a mean of 187 months. We diagnosed renal pathology as classes, active and sclerosing lesions, according to the new and WHO1995 classification of LGN, and analyzed the clinicopathologic factors affecting to the prognosis of LGN. RESULTS: New classification got much higher consensus in the judgment of classes (98% vs. 83%, P = 0.0084). The group of Class IV-S (N = 6) or IV-G (N = 17) at initial biopsies showed higher rate of end-stage renal failure (ESRF) compared with that of Class I, II, III or V (40.9% vs. 2.6%, P < 0.001). The mean 50% renal survival time of Class IV was 189 +/- 29 months, and patients with Class IV-S tended to have a poorer prognosis (95 +/- 22 months for IV-S vs. 214 +/- 35 months for IV-G, P = 0.1495). Class IV was also selected as the most significant risk factor for ESRF by stepwise model (P = 0.002). In subanalysis for ESRF in Class IV (-S or -G), treatment including methylprednisolone pulse therapy was only selected as a significant improving factor for primary outcome (P = 0.034). In addition, activity index was the significant risk factor of death and/or ESRF after initial renal biopsies (P = 0.043). As for actuarial patient death during all follow-up periods, complications with anti-phospholipid syndrome or nephrotic syndrome were significant risk factors (P = 0.013, P = 0.041, respectively). CONCLUSION: New ISN/RPS 2003 classification provided beneficial pathologic information relevant to the long-term renal outcome and the optimal therapy preventing ESRF and/or death in patients with LGN.

Adolescent↗
PubMed2004

CD68 and MCP-1/CCR2 expression of initial biopsies reflect the outcomes of membranous nephropathy.

BACKGROUND: A considerable diversity of prognosis is seen with idiopathic membranous nephropathy (IMN). The initial factors affecting long-term outcome remain unclear. METHODS: We studied retrospectively 30 patients with IMN who had been followed up for at least 5 years, or until end-stage renal failure (ESRF). We analyzed the prognostic factors of ESRF in the first renal biopsies; these factors included presence of tubulointerstitial lesions and foam cells, as well as expression of CD68, monocyte chemoattractant protein-1 (MCP-1), its cognate receptor chemokine receptor 2 (CCR2) and alpha-smooth muscle actin. RESULTS: The patients who developed ESRF showed higher percentages of glomerular segmental sclerosis, interstitial MCP-1 expression, CCR2- or CD68-positive monocyte/macrophages and foam cells in the interstitium, and these proved on multivariate analysis to be independent risk factors for ESRF. Finally, ESRF was characterized by the presence of ten interstitial CD68-positive cells per visual field at 200x magnification (hazard ratio 4.096, CI 1.271-15.029, p < 0.001). CONCLUSIONS: Our results suggested that an interstitial infiltration of CD68-positive cells accompanied by MCP-1/CCR2 expression is the most significant indicator of ESRF in IMN.

Antigens, CD↗
PubMed2004

Malignant gastrointestinal stromal tumor originating in the lesser omentum, complicated by rapidly progressive glomerulonephritis and gastric carcinoma.

A 69-year-old man was admitted with a large elastic mass in the upper abdomen. Computed tomography revealed a massive tumor in contact with the liver and gastrointestinal endoscopy revealed a gastric adenocarcinoma. He developed acute renal failure with massive proteinuria and died with a marked enlargement of the tumor. Autopsy revealed a tumor located in the lesser omentum. The tumor was considered to be a Gastrointestinal Stromal Tumor (GIST) because it was positive for c-kit. In addition, crescent formations and immune complexes in glomeruli were observed. We report the first case of GIST complicated by rapidly progressive glomerulonephritis and gastric carcinoma.

Acute Kidney Injury↗