Publications by authors named "Nobuaki Yamanaka"

Background: Renin-angiotensin-aldosterone system blockers are known to reduce hypertrophy of vascular smooth muscle cells (SMCs) in hypertensive cases. However, we have reported marked proliferative changes of renal afferent arteriolar SMCs in rats induced by a long-term administration of angiotensin II type 1 receptor blockers (ARBs) and an angiotensin-converting enzyme inhibitor (ACEI). In this study, we examined the morphological changes of afferent arteriolar walls in human kidneys with or without ARBs/ACEIs.

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Background Recently, we showed that long-term angiotensin receptor blocker (ARB) administration induced unusual proliferative changes in smooth muscle cells (SMCs) of afferent arterioles of the kidneys of Zucker fatty rats (ZFRs). In this study, we investigated renal afferent arteriolar changes induced by the long-term administration of an angiotensin converting enzyme inhibitor (ACEI) in ZFRs. Materials and Methods Fourteen 6-week-old male ZFRs were divided into two groups (n=14): the ZFR+ACEI group (n=6) was fed a standard diet containing ACEI (Enalapril, 2 mg/kg/day), and the ZFR control group (n=8) for 12 weeks.

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Background/aims: We have reported that the long-term administration of angiotensin II receptor blockers (ARBs) induced unusual proliferative changes of renal afferent arteriolar smooth muscle cells (SMCs) in rats, associated with the overproduction of renin. In this study, we examined that a direct renin inhibitor (DRI: Aliskilen; Novartis Pharma Co, USA) might induce different changes on afferent arteriolar walls compared to ARBs.

Method: Twenty one 6-weeks-old male spontaneous hypertensive rats (SHRs) were divided into the following three groups: high-dose DRI group (n=7), low-dose DRI group (n=5) and control group (n=9).

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Background/aims: Immunologically and hemodynamically mediated the destruction of glomerular architecture is thought to be the major causes of end-stage renal failure. The purpose of this study is to evaluate the effect of glomerular hypertension on glomerular injury and the progression of glomerular sclerosis after Thy-1 nephritis was induced.

Method: Thy-1 nephritis was induced in the stroke-prone spontaneously hypertensive rat strain (SHR-SP) (group SP) and in age-matched Wistar-Kyoto (WKY) (group WKY) rats, following unilateral nephrectomy (UNX), and a vehicle was injected alone in UNX SHR-SP as control (group SC).

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Background: The glomerulus contains well-developed capillaries, which are at risk of injury due to high hydrostatic pressure, hyperfiltration, hypertension and inflammation. However, the pathological alterations of the injured glomerular basement membrane (GBM), the main component of the glomerular filtration barrier, are still uncertain in cases of glomerulonephritis.

Methods: We examined the alterations of the GBM in 50 renal biopsy cases with IgA nephropathy (31.

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Introduction: Our previous study of angiotensin II receptor blocker (ARB) administration in rats induced unusual proliferative changes of smooth muscle cells in renal arteriolar walls. The present study examined if the incidence of the changes depended on the rats' age, and how long it would take to find changes.

Materials And Methods: Six-week-old (juvenile spontaneous hypertensive rats (SHRs)+ARB group, n=15) and 20-week-old (adult SHRs+ARB group, n=10) male SHRs were fed a standard diet (0.

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Although tubulointerstitial nephritis with IgG4+ plasma cell (PC) infiltration is a hallmark of IgG4-related kidney disease (IgG4-RKD), only a few studies are available about the minimum number of IgG4+ PC needed for diagnosis along with IgG4+/IgG+ PC ratio in the kidney. In addition, the significance of the deposition of IgG or complement as a reflection of humoral immunity involvement is still uncertain. In this study, we analyzed 20 Japanese patients with IgG4-RKD to evaluate the number of IgG4+ PCs along with IgG4+/IgG+ PC ratio and involvement of humoral immunity.

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Background: IgG4-related disease has attracted wide attention recently. It is characterized by a high level of serum IgG4 and dense infiltration of IgG4-positive plasma cells into multiple organs, with the kidney being one representative target. Although several sets of diagnostic criteria for autoimmune pancreatitis (AIP) are available and renal lesion is recognized as an extra-pancreatic manifestation of AIP, it is difficult to differentiate IgG4-related tubulointerstitial nephritis (TIN) without AIP from other types of TIN.

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Nephropathy associated with IgG4-related disease is characterized by tubulointerstitial nephritis. To better identify its pathology, the present study analyzed clinicopathologic features of IgG4-related tubulointerstitial nephritis cases from across Japan. Sixteen cases were identified as IgG4-related nephropathy using the criterion of high serum IgG4 levels (>135 mg/dL) with abnormal kidney computed tomography or elevated serum creatinine levels.

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Introduction: The nephro-protective effects of angiotensin II receptor blockers (ARBs) are widely known; however, there are few reports of long-term effects focusing on the renal vessels. We studied afferent arteriolar changes induced by the long-term administration of an ARB.

Materials And Methods: Thirty-two 6-week-old male Zucker fatty rats (ZFRs) were divided into following four groups (n = 8 in each): ZFR Group and ZFR+High Group fed a standard or high-salt diet, respectively; ZFR+ARB Group and ZFR+High+ARB Group fed a standard or high-salt diet with ARB (Olmesartan, 5 mg/kg/day), respectively.

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Background: Renal diseases in diabetes include diabetic nephropathies (DN) and non-diabetic renal diseases (NDRD). The clinical differentiation between these two categories is usually not so clear and effective. This study aims to develop a quantified differential diagnostic model.

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Background: Signal transducers and activators of transcription (STATs) are cytoplasmic proteins that are activated in response to stimulation from various cytokines. Among these, STAT3 is an important member that has been implicated in the inflammatory proliferation of cells. We hypothesized that STAT3 may be activated in kidneys of rats having modified chronic immune complex glomerulonephritis, and that angiotensin-converting enzyme (ACE) inhibition with fosinopril may prevent the activation of STAT3 and subsequent upregulation of tissue inhibitor of metalloproteinase-1 (TIMP-1), which are effects that may explain the therapeutic effects of fosinopril on nephritis.

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Background: Although the clinical importance of immunoglobulin-A nephropathy (IgAN) is widely recognized, the characteristics of intrarenal arterial lesions in this disease and the main factors associated with them have not been studied extensively, and a large-scale analysis of intrarenal arterial lesions in IgAN has not been performed.

Methods: To clarify these issues, we investigated the prevalence, underlying factors and significance of intrarenal arterial lesions in 1005 patients with IgAN. We distinguished different degrees of severity of small artery and arteriolar lesions (mild, moderate and severe), using a semi-quantitative scoring system.

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Hepatocyte growth factor (HGF) is one of the major growth factors that stimulate the growth and the migration of vascular endothelial cells. In this study, we examined the beneficial effects of HGF for glomerular repair in an experimental progressive glomerulonephritis (GN) model prepared by injecting both anti-Thy-1.1 antibody (day 0) and habu-snake venom (day 1) in rats.

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Cyclooxygenase (COX), an enzyme essential for prostaglandin biosynthesis, has two isoforms, COX-1 and -2. We investigated temporal and spatial changes in localization of these two COX proteins and mRNAs after excisional injury in rat skin. We also quantified the expression of these proteins and studied the effects of a specific COX-2 inhibitor on healing.

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Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory segmental arterial occlusive disorder that involves primarily the renal and carotid arteries, and less often the coronary, iliac, and visceral arteries. We report the case of 78-year-old Japanese woman who presented with acute abdomen complicated by shock. Autopsy revealed hemorrhagic necrosis of the small intestine due to severe narrowing of the mesenteric arteries.

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Injury to the renal microvasculature may be a major factor contributing to the progression of renal disease. Although severe disruption of peritubular capillaries (PTC) could lead to marked tubulointerstitial scarring, elucidation of that process remains incomplete. This study investigated the morphologic changes in PTC and their likely regulation by vascular endothelial growth factor (VEGF) during the progression of tubulointerstitial injuries.

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The functional and morphologic changes occurring in the peritubular capillaries (PTC) of the kidney during the progression of renal disease are not yet completely understood. In this study, the features of PTC disruption observed in a rat anti-glomerular basement membrane-induced glomerulonephritis (GN) model were characterized. Contributions to the progression of the disease made by other interstitial components, including ED-1-positive macrophages and CD3-positive T cells, were also investigated.

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