Search PubMed⌕ Search

Biomedical subjects

Fumitake Gejyo

Publications and source records attributed to Fumitake Gejyo.

At least 19 recordsLinked to original sources
PubMed2005

Epidermis-targeted gene transfer using in vivo electroporation.

The skin is an important target for gene transfer because of its easy accessibility. Recently, we demonstrated that an in vivo electroporation approach could be applied to plasmid deoxyribonucleic acid delivery in rat skin of the abdominal area. Plate-and-fork type electrodes were effective for gene delivery by skin-targeted gene transfer. Eight 12-24 V, 50-m electric pulses were delivered through the electrodes. Skin injection with pCAGGS-lacZ showed lacZ gene expression in the upper most cell layers (horny, granular, and prickle cell layers) of the epidermis on day 1 and in the subcutaneous muscle layer on day 7 after the pCAGGS-lacZ transfer. Slight skin damage as the result of the gene transfer procedure was evident on day 1 but absent by day 7. These results demonstrate that plasmid deoxyribonucleic acid transfer by in vivo electro poration at low voltage is a useful procedure for short-term skin-targeted gene transfer.

Animals↗
PubMed2004

Association of a single-nucleotide polymorphism in the immunoglobulin mu-binding protein 2 gene with immunoglobulin A nephropathy.

Immunoglobulin A (IgA) nephropathy is the most common form of primary glomerulonephritis worldwide. The pathogenesis of IgA nephropathy is unknown, but it is certain that some genetic factors are involved in susceptibility to the disease. Employing a large-scale, case-control association study using gene-based single-nucleotide polymorphism (SNP) markers, we previously reported four candidate genes. We report here an additional significant association between IgA nephropathy and an SNP located in the gene encoding immunoglobulin micro-binding protein 2 (IGHMBP2) at chromosome 11q13.2-q13.4. The association (chi2 =17.1, p = 0.00003; odds ratio of 1.85 with 95% confidence interval of 1.39-2.50 in a dominant association model) was found using DNA from 465 affected individuals and 634 controls. The SNP (G34448A) caused an amino acid substitution from glutamine to lysine (E928K). As the gene product is involved in immunoglobulin-class switching and patients with the A allele revealed higher serum levels of IgA (p = 0.048), the amino acid change might influence a class switch to increase serum IgA levels, resulting in a higher risk of IgA nephropathy.

Adult↗
PubMed2004

Natural saline-flush is sufficient to maintain patency of immobilized-urokinase double-lumen catheter used to provide temporary blood access for hemodialysis.

BACKGROUND: Thrombotic occlusion is a frequent complication of central venous catheters used to provide temporary blood access on hemodialysis therapy. Heparin-lock is conventionally used to maintain patency of the catheter, but the necessity of heparin-lock has not been determined yet. METHODS: After the immobilized-urokinase double-lumen central venous catheter was inserted into 48 Japanese hemodialysis patients, 22 patients randomized to the heparin group received a 20-ml saline-flush, followed by 2 ml of 1,000 U/ml heparin-lock, and 26 patients randomized to the saline group received only the 20-ml saline-flush once a day for each lumen. RESULTS: Thrombotic occlusion was observed in only 1 out of 22 patients in the heparin group and 1 out of 26 patients in the saline group. No significant difference of the catheter survival was observed between the two groups (p = 0.8599). CONCLUSIONS: Natural saline-flush is sufficient for maintaining the patency of an immobilized-urokinase double-lumen central venous catheter.

Aged↗
PubMed2004

Low concentrations of sodium dodecyl sulfate induce the extension of beta 2-microglobulin-related amyloid fibrils at a neutral pH.

In beta(2)-microglobulin-related (Abeta2M) amyloidosis, partial unfolding of beta(2)-microglobulin (beta2-m) is believed to be prerequisite to its assembly into Abeta2M amyloid fibrils in vivo. Although low pH or 2,2,2-trifluoroethanol at a low concentration has been reported to induce partial unfolding of beta2-m and subsequent amyloid fibril formation in vitro, factors that induce them under near physiological conditions have not been determined. Using fluorescence spectroscopy with thioflavin T, circular dichroism spectroscopy, and electron microscopy, we here show that at low concentrations, sodium dodecyl sulfate (SDS) converts natively folded beta2-m monomers into partially folded, alpha-helix-containing conformers. Surprisingly, this results in the extension of Abeta2M amyloid fibrils at neutral pH, which could be explained basically by a first-order kinetic model. At low concentrations, SDS also stabilized the fibrils at neutral pH. These SDS effects were concentration-dependent and maximal at approximately 0.5 mM, around the critical micelle concentration of SDS (0.67 mM). As the concentration of SDS was increased above 1 mM, the alpha-helix content of beta2-m rose to approximately 10%, while the beta-sheet content decreased to approximately 20%, a change paralleled by a complete cessation of fibril extension and the destabilization of the fibrils. Detergents of other classes had no significant effect on the extension of fibrils. These findings are consistent with the hypothesis that in vivo, specific factors (e.g., phospholipids) that affect the conformation and stability of beta2-m and amyloid fibrils will have significant effects on the kinetics of Abeta2M fibril formation.

Amyloid↗
PubMed2004

Evidence indicating that renal tubular metabolism of leptin is mediated by megalin but not by the leptin receptors.

Leptin is secreted by adipocytes and is a circulating factor that regulates food intake and energy expenditure. Its serum level is elevated in patients with renal failure and has been suggested to be associated with malnutritional factors in these patients. Leptin has been suggested to be primarily metabolized by the kidneys, although the precise molecular mechanisms are not known. The purpose of this study was to determine the nephron segments and potential receptors involved in renal leptin metabolism. To determine the segment involved in leptin uptake, we performed histoautoradiography of kidney sections obtained from rats that had been injected iv with (125)I-leptin. The ability of megalin, a multiligand endocytic receptor in the proximal tubules, to bind and endocytose leptin was examined by ligand blotting analysis, quartz-crystal microbalance, and degradation assays using megalin-expressing rat yolk sac L2 cells. Immunohistochemistry was performed to localize leptin receptors (LEP-R) in the rat kidney using two antibodies that recognize different epitopes on the LEP-R proteins. Circulating (125)I-leptin was filtered by glomeruli and internalized by proximal convoluted tubules. Megalin bound leptin in the presence of Ca(2+) and mediated its cellular internalization and degradation. On immunohistochemistry, LEP-R were localized in the proximal straight tubules, loops of Henle, distal tubules, and collecting ducts. In conclusion, circulating leptin was filtered by glomeruli and taken up by proximal convoluted tubules, where megalin likely mediates its binding and uptake. The localization of LEP-R suggests that they are not primarily involved in leptin metabolism in the proximal tubules.

Animals↗
PubMed2004

Mixed connective tissue disease associated with antineutrophil cytoplasmic antibodies against proteinase-3 and systemic atherosclerosis: a case report.

A 47-year-old woman presented with facial spasm, swollen fingers and Raynaud's phenomenon due to cerebrovascular disorder and mixed connective tissue disease (MCTD). Although she was positive for both antineutrophil cytoplasmic antibodies against proteinase-3 (PR3-ANCA) and anti-U1 RNP antibodies, she did not meet the American College of Rheumatology classification criteria for Wegener's granulomatosis (WG). Physical and histopathological examinations revealed severe systemic atherosclerosis without any of the traditional risk factors. Elevated levels of malondialdehyde-modified LDL and antioxidized LDL autoantibodies, which are considered to be key factors in the pathogenesis of atherosclerosis, were also detected in the serum of this patient. In this case, systemic atherosclerosis might have been linked to these autoimmune reactions.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2004

Different type and localization of CD44 on surface membrane of regenerative renal tubular epithelial cells in vivo.

BACKGROUND: CD44 is a transmembrane glycoprotein comprising an extracellular domain, a transmembrane domain, and a cytoplasmic tail. Previous studies demonstrated that CD44 was generally restricted to lateral-basal plasma membrane (PM) of epithelial cells, whether it localized on apical PM in vivo has not been clarified. METHODS: In this study, we used a gentamicin-induced acute tubular necrosis (ATN) and spontaneous recovery model in rats and two distinct antibodies, an anti-rat distal extracellular domain (OX49) of standard CD44 (CD44-OX49) and an anti-rat CD44 cytoplasmic tail (CD44CPT), to survey the localization of CD44-OX49 and CD44CPT on the PM in renal tubular epithelial cells in different recovery stages after ATN with immunohistochemistry and immunoelectron-microscopic examinations. RESULTS: CD44-OX49 was localized not only on the lateral-basal PM in tubular epithelial cells, but also on the apical surface membrane in PCNA-positive newly regenerative tubular epithelial cells in early recovery stages after ATN. However, CD44CPT was only localized on the lateral-basal PM. The immunoelectron-microscopic results showed that CD44-OX49 localization was changed from the apical to lateral to basal surface membrane in renal tubular epithelial cells during the recovery process after ATN, finally disappearing from basal PM when normal polarized epithelial cells formed. CONCLUSIONS: These results suggest that there were two types of CD44 including CD44 without a cytoplasmic tail localizing on the apical surface membrane related to newly regenerative epithelial cells, and CD44 with a cytoplasmic tail localizing on the lateral-basal PM related to establishment of tubular epithelial cell polarity after ATN in vivo.

Animals↗
PubMed2004

PDZ domain-binding motif of human T-cell leukemia virus type 1 Tax oncoprotein augments the transforming activity in a rat fibroblast cell line.

While human T-cell leukemia virus type 1 (HTLV-1) is associated with the development of adult T-cell leukemia (ATL), HTLV-2 has not been reported to be associated with such malignant leukemias. HTLV-1 Tax1 oncoprotein transforms a rat fibroblast cell line (Rat-1) to form multiple large colonies in soft agar, and this activity is much greater than that of HTLV-2 Tax2. We have demonstrated here that the increased number of transformed colonies induced by Tax1 relative to Tax2 was mediated by a PDZ domain-binding motif (PBM) in Tax1, which is absent in Tax2. Tax1 PBM mediated the interaction of Tax1 with the discs large (Dlg) tumor suppressor containing PDZ domains, and the interaction correlated well with the transforming activities of Tax1 and the mutants. Through this interaction, Tax1 altered the subcellular localization of Dlg from the detergent-soluble to the detergent-insoluble fraction in a fibroblast cell line as well as in HTLV-1-infected T-cell lines. These results suggest that the interaction of Tax1 with PDZ domain protein(s) is critically involved in the transforming activity of Tax1, the activity of which may be a crucial factor in malignant transformation of HTLV-1-infected cells in vivo.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Renal function at the time of renal biopsy as a predictor of prognosis in patients with primary AL-type amyloidosis.

BACKGROUND: Amyloid light-chain (AL)-type amyloidosis is a plasma cell disorder with a poor prognosis for survival. Although prognostic factors, such as the number of organs involved and heart function or failure in respond to therapy have been clarified based on studies including a large series of patients, there are large interindividual differences in the prognosis of patients with primary AL-type renal amyloidosis. METHODS: To clarify the prognostic factors of AL-type renal amyloidosis, we retrospectively investigated the clinical manifestations, histopathological data, and prognosis of 21 patients with amyloidosis, who had been diagnosed by renal biopsy. RESULTS: Eleven patients died, at a mean observational time of 21.7 months after renal biopsy, whereas the mean observational time was 51.0 months for the 10 patients who survived. The creatinine clearance rate was significantly higher, and the serum creatinine concentration and the grade of interstitial damage were significantly lower in surviving patients (P < 0.05). The presence of amyloid fibrils in organs other than the kidney did not influence prognosis for survival. However, the intraventricular septum was thinner in surviving patients (P < 0.1). Thirteen patients had undergone melphalan-prednisolone therapy, but it did not affect prognosis for survival. Cox proportional hazard regression analysis revealed that the renal function at the time of diagnosis was a significant and independent prognostic factor for survival. CONCLUSIONS: Our study demonstrated that renal function at the time of biopsy and renal interstitial damage are the best predictors of survival in AL-type renal amyloidosis.

Amyloid↗
PubMed2004

Increase in the ratio of matrix metalloproteinase-9 to tissue inhibitor of metalloproteinase-1 in saliva from patients with primary Sjögren's syndrome.

BACKGROUND: To investigate the ratio of matrix metalloproteinase (MMP) to tissue inhibitor of metalloproteinase (TIMP) in primary Sjögren's syndrome (PSS), patients and healthy subjects MMP-2, 9 and TIMP-1, 2 levels were measured in saliva. METHODS: Stimulated whole-mixed saliva was collected from 32 patients and 26 healthy subjects. MMP-2, 9 and TIMP-1, 2 levels were measured using enzyme-linked immunosorbent assay (ELISA) and the sandwich enzyme immunoassay (sandwich EIA). Zymography and reverse zymography were used to identify MMPs and TIMPs. RESULTS: MMP-9 (gelatinase-B) level in saliva was significantly increased in the patients. MMP-9 (ng/ml): patients 231.02 +/- 151.77 (mean +/- S.D.), healthy subjects 145.87 +/- 111.65 (p < 0.05). MMP-2 levels were not detected with this system kit in either healthy subjects or patients. The differences in TIMPs were only trends and not statistically significant (p > 0.05). Accordingly, MMP-9/TIMP-1 was greatly increased in the patients (2.60 +/- 1.18) than in the healthy subjects (1.28 +/- 1.11) (p < 0.01). CONCLUSION: This study found that MMP-9/TIMP-1 and MMP-9 levels in the saliva were significantly higher in pSS patients than those in healthy subjects. Our results indicate that the increase in MMP-9/TIMP-1, rather than the increase in MMP-9, in pSS patients' saliva is strongly involved in destruction of glandular and salivary duct tissues.

Enzyme-Linked Immunosorbent Assay↗
PubMed2004

Visualization of a functional KSHV episome-maintenance protein LANA in living cells.

The latency-associated nuclear antigen (LANA) of Kaposi's saroma-associated herpesvirus (KSHV) can maintain a plasmid containing the KSHV origin of DNA replication (oriP) as episomes in dividing human cells. Hence, LANA is considered to play crucial roles in persistent KSHV infection in human cells. In this study, we characterized a LANA fusion protein of green fluorescent protein (GFP-LANA). Like the wild-type LANA, GFP-LANA interacted tightly with mitotic chromosomes, and maintained the plasmid selectively with the KSHV oriP for more than three weeks in a human B cell line. Moreover, equivalent amount of GFP-LANA protein was segregated into two daughter cells in living metaphase cells. Our results suggested that the activity of LANA serves the segregation of equivalent amounts of viral genomes tethered with LANA into two daughter progeny cells during cell division. Thus, GFP-LANA is a useful tool for the analyses of the functions and dynamics of LANA in living cells.

Antigens, Viral↗
PubMed2004

Short-term use of continuous positive airway pressure ameliorates glomerular hyperfiltration in patients with obstructive sleep apnoea syndrome.

Patients with OSAS (obstructive sleep apnoea syndrome) demonstrate renal signs such as proteinuria, glomerular hypertrophy and focal glomerular sclerosis. We performed a clinical study to investigate the glomerular function in OSAS patients and the short-term effect of CPAP (continuous positive airway pressure) on it. OSAS patients underwent a sodium thiosulphate and p-aminohippurate double clearance test, polysomnography and ambulatory blood pressure monitoring before and a week after the induction of CPAP. Twenty-seven consecutive patients (24 males) with moderate-to-severe OSAS admitted to our hospital for the induction of CPAP, and 32 healthy donors for renal transplantation as controls participated in the study. Before treatment, the glomerular filtration rate, estimated by the sodium thiosulphate clearance test, was within normal range, and the renal plasma flow was significantly lower than normal in the OSAS patients, thus the FF (filtration fraction) value was much higher than normal. FF before CPAP was not significantly correlated with age, body mass index or blood pressure; however, indices of increased hypoxaemia correlated with increased FF values. Polysomnographic variables after CPAP showed significant improvements in all patients, and only the nocturnal blood pressures were slightly lower than before CPAP. In 21 patients who underwent the clearance test after CPAP, FF significantly decreased from 0.26 +/- 0.04 to 0.23 +/- 0.03 (P < 0.001). OSAS patients were generally in a glomerular-hyperfiltrating condition that appeared to cause the renal findings associated with OSAS. CPAP might prevent nephropathy by ameliorating the glomerular hyperfiltration in OSAS patients.

Aged↗
PubMed2004

Possible involvement of circulating fibroblast growth factor 23 in the development of secondary hyperparathyroidism associated with renal insufficiency.

BACKGROUND: Fibroblast growth factor 23 (FGF-23) is a recently identified polypeptide that promotes renal phosphate excretion and decreases serum 1,25-dihydroxyvitamin D3 (1,25D) levels. Serum FGF-23 levels are extraordinarily elevated in patients with end-stage renal failure. METHODS: Blood and urine samples were obtained from 62 predialysis patients (age, 51.3 +/- 14.0 years; range, approximately 18 to 76 years; 32 men, 30 women). Serum FGF-23 levels were determined by means of a sandwich enzyme-linked immunosorbent assay system using 2 kinds of monoclonal antibodies that does not detect biologically inactive N-terminal and C-terminal fragments derived from an identified internal cleavage site to date. RESULTS: Serum FGF-23 levels increased with the decrease in creatinine clearance (Ccr). Both intact parathyroid hormone (PTH) and 1-84 PTH levels correlated closely with FGF-23 levels (r2 = 0.857; r2 = 0.860). A negative correlation between serum concentrations of FGF-23 and 1,25D (r2 = 0.255) was found. The maximum tubular reabsorptive rate of phosphate correlated negatively with serum FGF-23 concentrations (r2 = 0.460). However, the amount of daily urinary phosphate excretion was significantly less in patients with a Ccr less than 30 mL/min (<0.50 mL/s; P < 0.01), whereas their circulating FGF-23 levels were significantly greater (P < 0.001). CONCLUSION: Circulating FGF-23 levels increase with the decrease in renal function. FGF-23 is a likely candidate to lead the reduction in serum 1,25D levels. FGF-23 becomes a potential uremic toxin to decrease 1,25D levels when it loses its hypophosphatemic action because of a decreased number of viable nephrons in patients with advanced renal failure. As such, FGF-23 may be an important determinant in the regulation of mineral metabolism with renal insufficiency.

Adolescent↗
PubMed2004

Intact PTH assay overestimates true 1-84 PTH levels after maxacalcitol therapy in dialysis patients with secondary hyperparathyroidism.

BACKGROUND: Although the so-called intact parathyroid hormone (iPTH) assay detects not only true 1-84 PTH (1-84PTH) but also large C-terminal PTH fragments, it remains inconclusive whether the 1-84PTH assay is more useful in clinical practice. Previous studies have shown that the results of these two PTH assays in dialysis patients are closely correlated. METHODS: Chronic dialysis patients whose plasma iPTH levels were >400 pg/ml were selected for inclusion in the present study. Following a 4 week wash-out time during which all vitamin D administration was halted, maxacalcitol was intravenously injected at the end of dialysis sessions three times per week for 24 weeks, at an initial dosage of 10 micro g. RESULTS: Ninety-seven patients with secondary hyperparathyroidism were included in our analysis. Their serum calcium levels were elevated from the start levels while phosphate levels remained unchanged. The plasma 1-84PTH levels constantly declined throughout the 24 weeks. Although the patients' plasma 1-84PTH and iPTH levels were closely correlated with each other both at the beginning of the study and after 24 weeks of maxacalcitol therapy, the ratio of 1-84PTH/iPTH consistently decreased throughout the study period (P<0.01). The changes in the ratio were significantly correlated with changes in serum calcium levels. CONCLUSIONS: Twenty-four weeks of intravenous maxacalcitol injection therapy significantly reduced the 1-84PTH/iPTH ratio. Estimated 1-84PTH levels from iPTH levels using a conversion formula obtained before the treatment were 21.0+/-20.4% higher than measured 1-84PTH levels after the therapy. Thus, iPTH measurement has a potential risk to overestimate 1-84PTH levels when evaluating the efficacy of maxacalcitol therapy in dialysis patients with secondary hyperparathyroidism.

Calcitriol↗
PubMed2004

Glycosaminoglycans enhance the trifluoroethanol-induced extension of beta 2-microglobulin-related amyloid fibrils at a neutral pH.

beta(2)-Microglobulin-related (A beta 2M) amyloidosis is a frequent and serious complication in patients on long-term dialysis, and beta(2)-microglobulin is a major structural component of A beta 2M amyloid fibrils. Several biologic molecules inhibiting the depolymerization of A beta 2M amyloid fibrils at a neutral pH were found recently. The effect of trifluoroethanol and glycosaminoglycans (GAG) on the extension of the fibrils at a neutral pH was investigated with the use of fluorescence spectroscopy with thioflavin T, circular dichroism spectroscopy, and electron microscopy. Trifluoroethanol at concentrations of up to 20% (vol/vol) caused fibril extension of heparin-stabilized seeds, inducing a subtle change in the tertiary structure of beta(2)-microglobulin and stabilizing the fibrils at a neutral pH. This extension reaction followed a first-order kinetic model. In addition, some GAG, especially heparin, dose-dependently enhanced the fibril extension. These results suggest that some GAG, especially heparin, may bind to the fibrils and enhance their deposition in vivo. Thus, the experimental system described here should be useful to search for the factors that accelerate A beta 2M amyloid deposition in vivo. In addition, the interference of the binding of GAG to A beta 2M amyloid fibrils may be an attractive therapeutic modality.

Amyloid↗
PubMed2004

Relationship between tonsils and IgA nephropathy as well as indications of tonsillectomy.

Although there are many papers about IgA nephropathy (IgAN) and tonsils, respectively, reviews about the relationship between tonsils, tonsillitis, tonsillectomy, and IgAN are limited. In this review, we introduced the structure, development, and function of tonsils, difference of tonsils with and without IgAN, consistency of both tonsillar IgA and glomerular IgA, the effect of tonsil stimulation, tonsil infection, and tonsillectomy on IgAN showed some evidences in which tonsils were closely related to IgAN and polymeric IgA1 deposited in glomerular mesangium were at least in part of tonsillar origin. Tonsillectomy can improve the urinary findings, keep stable renal function, improve mesangial proliferation and IgA deposit, have a favorable effect on long-tern renal survival in some IgAN patients, and do not cause significant immune deficiency and do not increase incidence of the upper respiratory tract infections, and can be used as a potentially effective treatment. The indications of tonsillectomy in patients with IgAN include mainly the deterioration of urinary findings after tonsillar infection, mild or moderate renal damage. However, tonsillectomy may not be enough and may not change the prognosis in IgAN patients with marked renal damage.

Bacterial Infections↗
PubMed2004

Real-time observation of glomerular hemodynamic changes in diabetic rats: effects of insulin and ARB.

BACKGROUND: The progression of diabetic nephropathy is closely related to disturbances in glomerular hemodynamics, such as glomerular hypertension and/or hyperperfusion. The aim of this study was to observe and to analyze glomerular hemodynamics in rats with diabetes mellitus (DM) in vivo using confocal laser scan microscopy (CLSM). We also examined the effects of candesartan cilexetil (TCV-116), a selective angiotensin II type 1 receptor blocker (ARB), on glomerular hemodynamics in DM. METHODS: Munich-Wistar rats were divided into six groups: (1) four-day control; (2) four-day DM; (3) 28-day control; (4) 28-day DM; (5) DM treated with insulin; (6) DM treated with TCV-116. The kidney-to-body weight ratio, glomerular volume, and proteinuria were estimated. Glomerular hemodynamic changes were observed using CLSM and renal expression of endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS) was evaluated by immunofluorescence. RESULTS: The kidney-to-body weight ratio, glomerular volume, the diameters of afferent arterioles (AA) and efferent arterioles (EA), erythrocyte velocities within glomeruli, and volume flow in glomerular capillary loops in four-day DM were significantly higher than in control rats, and increases were even more pronounced in the 28-day DM. TCV-116 treatment ameliorated all these findings and significantly decreased proteinuria, but there was no effect on the blood glucose level. On the other hand, insulin treatment was followed by normalization of all these changes induced in DM. Enhanced renal expression of eNOS in DM was suppressed when treated with either TCV-116 or insulin, while expression of nNOS was unaltered among the four groups. CONCLUSION: This imaging procedure allowed us to evaluate glomerular microcirculation in vivo, including the diameters of AA and EA, erythrocyte velocity, and volume flow. DM significantly induced glomerular hemodynamic alteration and renal hypertrophy. DM treated with either insulin or ARB ameliorated these changes. This study shows that progress in imaging technology promises to make major contributions to revealing the involvement of hemodynamic changes in glomerular diseases, aiding prognosis and the monitoring of therapeutic effects, as well.

Angiotensin II Type 1 Receptor Blockers↗