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Biomedical subjects

Akira Hishida

Publications and source records attributed to Akira Hishida.

102 records · Page 6Linked to original sources
PubMed2002

Recovery from hemodialysis therapy in a patient with renal cholesterol crystal embolism.

The prognosis of renal cholesterol crystal embolism (CCE) is poor, and many patients progressively develop to the end-stage of chronic renal failure. We herein experienced a 66-year-old male patient who recovered from hemodialysis (HD) shortly after an amputation of inflammatory toes. The patient complained of painful digital cyanosis at bilateral toes and livedo reticularis at right lower leg 4 weeks following aortic angiography. Laboratory examinations revealed eosinophilia and overt proteinuria (3.0 g/day). His serum creatinine level increased from 2.18 to 8.57 mg/dl over 6 weeks, and HD treatment was started. Treatment with simvastatin (5 mg/day) did not reverse renal failure and hypereosinophilia, but the amputation of right gangrene toes promptly increased urine output and eosinophilia completely disappeared concomitantly with a decline of C-reactive protein from 9.7 to 0.7 mg/dl. Serum creatinine level was also reduced to 3.46 mg/dl, and he eventually stopped HD totally after 32 sessions. This case suggested that the surgical amputation promptly recovered renal function. Reversal of inflammation may be more effective than lipid-lowering therapy for renal failure in our patient.

Aged↗
PubMed2002

Mechanisms and kinetics of Bowman's epithelial-myofibroblast transdifferentiation in the formation of glomerular crescents.

BACKGROUND: We investigated the mechanisms and kinetics of Bowman's epithelial-myofibroblast transdifferentiation in the formation of glomerular crescents. METHODS: Crescentic glomerulonephritis was induced by i.v. injection of rabbit anti-rat glomerular basement membrane antiserum in WKY rats. RESULTS: Cellular crescents (83.5% of glomeruli) were first observed at day 7 after disease induction. Immunostaining of alpha-smooth muscle actin (alpha-SMA), as a marker for the myofibroblast phenotype, was found in some periglomerular regions as early as day 3, when it was also seen in parietal epithelial cells (PEC) of Bowman's capsule at day 5 and in crescent formation at day 7. Proliferation marker Ki67-positive PEC was found at day 3, and double Ki67- and alpha-SMA-positive PEC could be seen at day 5. The migratory figure of PEC with the expression of alpha-SMA was found by immunoelectron microscopy. At day 7, some crescent cells were stained positive for PEC marker, protein gene product 9.5, in association with alpha-SMA or Ki67. Expression of transforming growth factor (TGF)-beta receptor types I and II, as well as platelet-derived growth factor (PDGF) receptor beta and PDGF-B increased in PEC as early as day 3. At day 5 marked deposition of cellular and common fibronectin, but not other extracellular matrix components examined was found in Bowman's spaces where ED 1-positive macrophages infiltrated. CONCLUSIONS: PEC may be stimulated to proliferate and/or transdifferentiate into myofibroblast phenotype possibly by action of TGF-beta and PDGF and/or binding of fibronectin to PEC, then migrate and/or proliferate, participating in glomerular crescents.

Activin Receptors, Type I↗
PubMed2002

A patient with sarcoidosis presenting with acute renal failure: implication for granulomatous interstitial nephritis and hypercalcemia.

A woman was admitted for acute renal failure and erythematous lesions. She was diagnosed with sarcoidosis after analysis of biopsy specimens revealed noncaseating epithelioid granulomas, elevated serum angiotensin-converting enzyme levels, and bilateral hilar lymphadenopathy. Serum concentrations of ionized calcium and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] were extremely high. Serum intact osteocalcin concentration and urinary deoxypyridinoline excretion were within reference ranges. Treatment with prednisolone induced a prompt improvement with normalization of serum concentrations of ionized calcium and 1,25-(OH)2D3. Serum intact osteocalcin concentration was markedly suppressed and urinary deoxypyridinoline excretion increased. It is possible suppressed bone resorption may be associated with overproduction of 1,25-(OH)2D3.

Acute Kidney Injury↗
PubMed2002

Glucose and oxygen hypometabolism in aceruloplasminemia brains.

OBJECTIVE: Aceruloplasminemia is an iron metabolic disorder caused by mutations in the ceruloplasmin gene. It is characterized by progressive neurodegeneration in association with iron accumulation. Excess iron functions as a potent catalyst of biologic oxidation. Previously we showed that an increased iron concentration is associated with the products of lipid peroxidation in the serum, cerebrospinal fluid, and brain tissues. To clarify the free radical-mediated tissue injury caused by intracellular iron accumulation through mitochondrial dysfunction. PATIENTS AND METHODS: We have measure brain oxygen and glucose metabolisms using positron emission tomography (PET) and examined brains at autopsy for iron contents and activities of the mitochondrial respiratory chain in two affected patients who had different truncation mutations of the ceruloplasmin gene. RESULTS: PET showed a marked decrease in glucose and oxygen consumption in the entire brain of aceruloplasminemia patients, with a preponderance of metabolic reduction in basal ganglia. Enzyme activities in the mitochondrial respiratory chain of the basal ganglia were reduced to approximately 45% and 42% respectively for complexes I and IV. An inverse relationship was shown between the amounts of iron accumulated and the levels of mitochondrial enzyme activities in all the brain regions examined. CONCLUSION: Iron-mediated free radicals may contribute to the impairment of mitochondrial energy metabolism in aceruloplasminemia.

Aged↗
PubMed2001

A novel recombinant hyperaffinity inositol 1,4,5-trisphosphate (IP(3)) absorbent traps IP(3), resulting in specific inhibition of IP(3)-mediated calcium signaling.

We have developed a novel recombinant hyperaffinity inositol 1,4,5-trisphosphate (IP(3)) absorbent, called the "IP(3) sponge," which we constructed on the basis of the ligand-binding site of the mouse type 1 IP(3) receptor (IP(3)R1). The IP(3) sponge exhibited approximately 1000-fold higher affinity for IP(3) than the parental IP(3)R1 and specifically competed with the endogenous IP(3)R for binding to IP(3). Trapping IP(3) with the IP(3) sponge inhibited IP(3)-induced Ca(2+) release (IICR) from cerebellar microsomes in a dose-dependent manner. The IP(3) sponge expressed in HEK293 cells also inhibited IICR in response to stimulation with carbachol or ATP. Its inhibitory effects were dependent upon the level of its expression over the increased IP(3) contents. Moreover, the IP(3) sponge significantly reduced the carbachol-induced phosphorylation of cAMP-response element-binding protein in HEK293 cells, indicating that the activation of cAMP-response element-binding protein by Ca(2+)-dependent phosphorylation may be partly attributable to IICR.

Adenosine Triphosphate↗
PubMed2001

Role of the increase in p21 in cisplatin-induced acute renal failure in rats.

The goal of this study was to clarify the role of p21, a cyclin-dependent kinase inhibitor, in acute renal failure (ARF). This was accomplished with the examination of the renal expression of p21 in cisplatin (CDDP)-induced ARF and in rechallenge injury with CDDP. The injection of CDDP (5 mg/kg) into rats induced increases in serum creatinine and tubular damage and the number of in situ DNA nick end labeling-positive cells, which peaked at day 5, followed by recovery to control levels by day 14. The rechallenge with the same dose of CDDP 14 d after the first dose of CDDP induced significantly less injury and no significant increase in in situ DNA nick end labeling-positive cells. The first CDDP dose significantly increased p53-positive nuclei at day 1, which disappeared by day 5, and the number of p21-positive nuclei, which had two peaks on days 3 and 9. The number of proliferating cell nuclear antigen (PCNA)-positive nuclei peaked at days 3 and 12. A significant increase in the incorporation of 5-bromo 2'-deoxyuridine (BrdU) was found at day 5 and peaked at day 7. The second injection of CDDP induced significant increases in the number of p21-, p53-, and PCNA-positive nuclei within 2 d but did not affect the incorporation of BRDU: These findings suggested that (1) CDDP induced two peaks of the increase in p21; (2) the first peak occurred shortly after CDDP and was accompanied by overexpression of p53 and PCNA but not with BrdU incorporation, possibly reflecting G1 arrest and DNA repair; (3) the second peak of p21 occurred through an p53-independent pathway and may contribute to cell differentiation; and (4) the overexpression of p21 and PCNA in rechallenge injury may contribute to acquired resistance in CDDP-induced ARF via enhanced DNA repair.

Acute Kidney Injury↗
PubMed2000

Elevated erythropoietin receptor and transforming growth factor-beta1 expression in stenotic arteriovenous fistulae used for hemodialysis.

The issue of whether recombinant human erythropoietin (rhEPO) increases thrombosis of arteriovenous (AV) fistulae used for hemodialysis remains unclear. Thrombosis often occurs at stenotic segments of fistulae where there is marked intimal hyperplasia and extracellular matrix accumulation. Increased expression of transforming growth factor-beta1 (TGF-beta1) has been shown to be involved in the development of atherosclerotic lesions by promoting intimal hyperplasia and extracellular matrix accumulation. To clarify the role of rhEPO in the development of stenosis of AV fistulae, this study examined expression of the erythropoietin receptor (EPO-R), TGF-beta1, plasminogen activator inhibitor type 1 (PAI-1), cellular fibronectin containing an extra domain A (EDA+), and TGF-beta1 mRNA, and assessed in situ rhEPO binding in tissue specimens from seven cutaneous veins and eight patent and seven stenosed portions of AV fistulae of patients undergoing dialysis. Prominent intimal hyperplasia was evident in the stenosed segments. Significant elevation in expression of EPO-R and TGF-beta1 was noted in patent AV fistulae compared to the cutaneous veins. Significant enhancement of EPO-R and TGF-beta expression was detected in the stenotic fistulae. Fibronectin EDA+ and PAI-1 expression was increased in intimal hyperplasia compared to patent fistulae and cutaneous veins. Elevated EPO-R expression was further confirmed by in situ binding of biotin-labeled rhEPO in stenosed tissue specimens. It is hypothesized that increased rhEPO binding due to elevated EPO-R expression contributes to the development of AV fistula stenosis caused by intimal hyperplasia and extracellular matrix accumulation in response to increased TGF-beta1 expression in patients receiving hemodialysis.

Adult↗
PubMedDate not supplied

Role of soluble receptors for tumor necrosis factor alpha in the development of hypoalbuminemia in hemodialysis patients.

BACKGROUND: Hypoalbuminemia is a significant predictor of mortality in patients on hemodialysis (HD). The cause of hypoalbuminemia in HD patients, however, remains to be clarified. Recent studies have demonstrated that high blood concentrations of soluble receptors for tumor necrosis factor (sTNFRs) are associated with malnutrition in a variety of diseases and that the blood sTNFRs concentrations are elevated in HD patients. METHODS: The serum concentrations of tumor necrosis factor alpha, sTNFR (p55 and p80), and interleukin (IL) 6 were measured in 21 HD patients with low (equal to or less than 3.6 g/dl) and in 19 HD patients with normal (equal to or more than 4.0 g/dl) concentrations of serum albumin who were free from acute infection, malignancy, collagen diseases, liver diseases, or surgery. The correlation between these parameters and the degree of hypoalbuminemia was examined. RESULTS: The serum concentrations of sTNFR p80 and IL-6 were significantly higher in patients with hypoalbuminemia as compared with those with normoalbuminemia (sTNFR p80: 47.4 +/- 4.7 vs. 35.3 +/- 2.1 ng/ml, p < 0.05; IL-6: 10.8 +/- 2.0 vs. 6.3 +/- 0.5 pg/ml, p < 0.05). In contrast, there was no difference in the serum concentrations of tumor necrosis factor alpha and sTNFR p55 between the two groups. Multivariate regression analysis showed that sTNFR p80 but not IL-6 significantly influenced the serum albumin concentrations. There were no significant differences in body mass index, serum total cholesterol, and normalized protein catabolic rate between the two groups. CONCLUSIONS: Our results suggest the development of hypoalbuminemia in some HD patients who do not have any obvious cause of hypoalbuminemia and that high concentrations of sTNFR p80 might contribute to the development of hypoalbuminemia in patients on long-term HD.

Adult↗
PubMedDate not supplied

Relation of distal nephron changes to proximal tubular damage in uranyl acetate-induced acute renal failure in rats.

AIMS: To elucidate the pathophysiological roles of the changes of distal nephron in uranyl acetate (UA)-induced acute renal failure (ARF), we investigated the relation of changes of constituent molecules in distal nephron to proximal tubular damage and repair in UA-treated rats. METHODS: ARF was induced in rats by intravenous injection of UA, and all rats received bromodeoxyuridine (BrdU) intraperitoneally 1 h before sacrifice. RESULTS: Proximal tubular damage with necrosis appeared as early as day 2, mainly in the outer stripe of outer medulla and reached a peak level at day 5. Slight cellular damage was evident in the distal nephron as early as day 3, reaching a peak level around day 9. Immunoreactive BrdU- or vimentin-positive regenerating proximal tubules (PT) appeared at day 2 and regenerating PT relining was almost completed by day 7. Immunostaining for EGF, which was constitutively expressed in the thick ascending limb (TAL) and distal convoluted tubule (DCT), diminished significantly as early as day 2, when PT regeneration became evident, and remained below normal levels until day 21. In contrast, slight immunoreactivity for EGF was observed in regenerated PT accompanying brush-border formation mainly after day 9, suggesting newly expressed EGF might contribute to PT maturation. Lectin staining or immunostaining for representative constituent molecules of the thin descending limb, TAL, DCT and collecting duct demonstrated marked and transient reduction after day 5. CONCLUSIONS: EGF was not associated with regenerating PT, but may be involved in the maturation of PT. Transient reduction in expression of constituent molecules of the distal nephron following the reduction in EGF could reflect dedifferentiation or phenotypic simplification during regenerative repair of PT in UA-induced ARF in rats.

Acute Kidney Injury↗