Biomedical subjects

Fuminori Sato

Publications and source records attributed to Fuminori Sato.

16 recordsLinked to original sources

PubMed2006

Gene silencing of myostatin in differentiation of chicken embryonic myoblasts by small interfering RNA.

Myostatin (GDF-8) is known to negatively regulate skeletal muscle mass in myogenesis, but few studies have been conducted on the function of endogenous GDF-8 in primary myoblasts. The present study was performed to assess the function of GDF-8 by RNA interference using primary culture of chicken embryonic myoblasts in which myoblasts were differentiated into myotubes. An active form of small interfering RNA (siRNA-1) targeting GDF-8 mRNA was introduced into myoblasts, and an inactive form of siRNA (siRNA-2) was used as a negative control. GDF-8 transcript level was significantly reduced 24 h after the introduction of siRNA-1 to 25% of the control, whereas a 52-kDa GDF-8 precursor was reduced to 45% of the control at 48 h. However, siRNA-2 did not decrease GDF-8 transcript level. When GDF-8-mediated promoter activity was measured chronologically by means of a pGL(CAGA)(10)-constructed luciferase reporter assay, a concomitant change in activity was initiated after 24 h. The activity rapidly decreased 30 h after siRNA-1 introduction, whereas high activity was maintained at 30-42 h in the control and siRNA-2-treated myoblasts. Myogenic factors such as MyoD and p21, but not myogenin, were altered after 72 h. Cell fusion of the multinucleated myotubes was delayed by the siRNA-1 introduction, and myotubes with aggregated nuclei were shorter and wider. These results strongly suggest that deficiency of GDF-8 delays cell differentiation and causes great alterations in the cellular morphology of chicken embryonic myotubes.

Animals↗

PubMed2006

SAA1 gene polymorphisms and the risk of AA amyloidosis in Japanese patients with rheumatoid arthritis.

To investigate the precise modality of association between SAA1 gene polymorphisms and the development of AA amyloidosis in patients with rheumatoid arthritis (RA), Japanese patients with RA (n=153), among whom 29 were histologically diagnosed as having amyloidosis, were genotyped for three single nucleotide polymorphisms (SNPs), C-13T, C2995T, and C3010T, in the SAA gene. Pairwise linkage disequilibrium coefficients between each pair of SNPs were calculated and estimated haplotype frequencies were compared between patients with and without amyloidosis. Possible associations between these SNPs and amyloidosis were analyzed by a case-control study and by the Kaplan-Meier method, in which the endpoint was defined as the time of diagnosis of AA amyloidosis. The -13T and 2995C alleles, which were in a tight linkage disequilibrium, were more frequent in the patients with amyloidosis, and the groups with the -13TT and 2995CC genotype had worse survival curves than patients without these genotypes, whereas C3010T was not associated with amyloidosis. Moreover, the haplotype containing -13C and 2995T was found to be protective. Both C-13T and C2995T were associated with the development of amyloidosis. Examining both polymorphisms may be more useful than examining only one of them for estimating the risk of the development of amyloidosis.

Aged↗

PubMed2006

Striated muscle fiber compositions of human male urethral rhabdosphincter and levator ani.

PURPOSE: We clarified the contractile properties of human male periurethral striated muscle fibers to better understand how the rhabdosphincter and the levator ani maintain urinary continence. MATERIALS AND METHODS: Muscle specimens were obtained from 52 male patients who underwent radical prostatectomy or radical cystectomy. The specimens were frozen in liquid nitrogen. Frozen sections (10 microm thick) were stained with myofibrillar ATPase at different pH values (pH 4.2, 4.6 and 10.6), and evaluated for quantitative parameters and fiber type distribution. Myosin heavy chain analysis was performed using SDS-PAGE. RESULTS: Of all 52 cases 37 provided specimens that could be divided into the 2 major fiber types, type 1 (slow twitch) and type 2 (fast twitch). Although type 1 muscle fibers were predominant in RS and LA muscle groups (RS 69.6 +/- 2.7%, LA 67.0 +/- 2.0%), mean muscle fiber size was significantly smaller in RS (mean area 906 +/- 86 microm(2)) than in LA (mean area 2,967 +/- 170 microm(2)) (p <0.0001). In 11 specimens type 2 muscle fibers could be subdivided into types 2A (fast fatigue resistant) and 2B (fast fatigable). Type 2A fibers were significantly more prevalent than type 2B fibers (p <0.05). Likewise, MHC analysis of these 11 specimens found a significantly higher percentage of fiber type 2A expression products (MHC 2A) than of fiber type 2B expression products (MHC 2X) (p <0.05). CONCLUSIONS: RS and LA contribute to urinary continence mechanism by slow contraction. Moreover, the smaller mean size of muscle fibers in RS suggests more fatigue resistance compared with muscle fibers in LA because small fibers have a shorter diffusion distance for metabolic substrates. These results should help contribute to a more detailed understanding of the function of periurethral striated muscles in the human male.

Aged↗

PubMed2005

Temporal and spatial expression of TGF-beta2 in chicken somites during early embryonic development.

A multifunctional growth and differentiation factor TGF-beta is expressed at various developmental stages, and its principle role may be involvement in organogenesis. The present study was performed to evaluate the temporal and spatial expression of TGF-beta2 mRNA in developing somites of chicken embryos during their early developmental periods. TGF-betas were expressed in various tissues of the whole embryo obtained at stage 26 (5 days of incubation) as revealed by whole-mount in situ hybridization. TGF-beta2 mRNA was predominantly expressed in somites as well as the head, branchial arch, wing buds, and leg buds. TGF-beta2 mRNA first appeared in the rostral somites on E4, and its expression sites expanded to the middle range of somites at stage 26. At stages 29-31 (6-7 days), expression in the rostral somites disappeared, and it appeared in the caudal somites. TGF-beta2 expression was also analyzed in sections of the embryo by in situ hybridization. The expression sites of TGF-beta2 were clearly observed in the myotomal somite tips as well as the neural tube. RT-PCR analysis showed that TGF-beta2 expression was very low in the blastocyte stage embryo and thereafter increased linearly in the whole trunk until stage 26. These data indicate that TGF-beta2 may be a regulatory factor participating in the somitogenesis of chicken embryos.

Age Factors↗

PubMed2005

Monocyte chemoattractant protein-1 A-2518G gene polymorphism and renal survival of Japanese patients with immunoglobulin A nephropathy.

BACKGROUND: Monocyte chemoattractant protein (MCP)-1 is closely related to the pathogenesis of the progression of various chronic renal diseases, including IgA nephropathy (IgAN), through its chemoattractant effect on macrophages. However, the correlation of MCP-1 gene polymorphism with the long-term prognosis of Japanese patients with IgAN has not been clearly determined yet. METHODS: We investigated 277 Japanese patients diagnosed with IgAN based on renal biopsy to clarify the association between the progression of IgAN and MCP-1 gene polymorphism at position A-2518G, which regulates the transcription of the MCP-1 gene. RESULTS: The incidence of endstage renal disease was significantly higher in patients with the AA genotype (47.1%) compared to those with the AG (24.1%) or GG (27.4%) genotype (P = 0.024). Moreover, Kaplan-Meier analysis revealed that the AA genotype significantly facilitated the progression of renal disease (log rank; P = 0.0029), and Cox proportional hazards regression model analysis showed that the AA genotype represented a 2.058-fold risk for the progression of renal disease (P = 0.026) compared to the AG/GG genotype. However, when the patients were treated with angiotensin-converting enzyme inhibitor and/or angiotensin receptor blocker, or corticosteroid, homozygosity for the -2518A allele was not associated with a higher rate of incidence of endstage renal disease. Serum MCP-1 levels were higher although not significantly so, in the patients with IgAN possessing the AA genotype. CONCLUSIONS: The AA genotype at MCP-1 -2518 was an independent risk factor for the progression of renal disease in Japanese patients with IgAN, and was closely associated with renal survival.

Adult↗

PubMed2005

Pretreatment serum FGF-23 levels predict the efficacy of calcitriol therapy in dialysis patients.

BACKGROUND: The predictor for the result of calcitriol therapy would be useful in the clinical practice of secondary hyperparathyroidism. Fibroblast growth factor-23 (FGF-23) is a newly found circulating phosphaturic factor. Its circulating level is elevated in uremia. METHODS: Dialysis patients with plasma intact parathyroid hormone (iPTH) levels greater than 300 pg/mL were included in the study. Calcitriol was intravenously injected three times a week. The patients whose plasma iPTH levels dropped below 300 pg/mL within 24 weeks were defined as those who had been successfully treated. A sandwich enzyme-linked immunosorbent assay (ELISA) system that detects human FGF-23 was applied. RESULTS: Sixty-two patients were analyzed. The pretreatment FGF-23 levels were related to the iPTH levels, calcium x phosphate product levels, and history of active vitamin D therapy. The pretreatment FGF-23, iPTH, and calcium levels were lower in the patients who would be successfully treated with calcitriol. A logistic regression study revealed that the pretreatment iPTH and FGF-23 levels significantly affected the therapy results. Analyses using a receiver-operated curve revealed that FGF-23 was the best screening test for identifying patients with future refractory response to calcitriol therapy. The treatment would be successful in 88.2% of those with FGF-23 </=9860 ng/L and iPTH </=591 pg/mL, while it would be successful in only 4.2% of those with FGF-23 >9860 ng/L and iPTH >591 pg/mL. CONCLUSION: Pretreatment serum FGF-23 levels were a good indicator in predicting the response to calcitriol therapy. The measurement of serum FGF-23 levels, especially in combination with iPTH levels, is a promising laboratory examination for the clinical practice of secondary hyperparathyroidism.

Calcitriol↗

PubMed2005

Bezafibrate suppresses rat antiglomerular basement membrane crescentic glomerulonephritis.

BACKGROUND: The immunoregulatory activity of ligands for peroxisome proliferator-activated receptors (PPARs) has been recently paid attention. The regulatory effect of bezafibrate (BZF), a ligand for PPARalpha on glomerulonephritis was investigated using a rat anti-glomerular basement membrane (GBM) glomerulonephritis model. METHODS: The effect on development of anti-GBM glomerulonephritis was examined by treatment with BZF from day -7 to day 7 after intravenous injection of rabbit anti-GBM serum into Wistar Kyoto (WKY) rats. The therapeutic efficacy after onset of the glomerulonephritis was also checked by treatment with BZF from day 3 to 7. On day 7, the condition was evaluated histologically. The expression of a tissue injury molecule, macrophage metalloesterase (MME), was measured by Northern blot analysis. The suppressive effect on immune cells was assessed by proliferation assay with mitogen-stimulated rat spleen cells. RESULTS: Histopathologic changes induced by anti-GBM in rats treated with BZF (day -7 to day 7) were markedly suppressed in a dose-dependent fashion. Infiltration of ED-1+ macrophages in glomeruli, proteinuria, and mRNA expression of MME in kidneys were diminished in parallel with histologic improvement. Moreover, the disease activity was also attenuated even by the treatment after onset of the glomerulonephritis (day 3 to 7). The mitogen-induced proliferation of spleen cells was down-regulated at concentrations of BZF, which were equivalent to those in sera of BZF-treated rats. CONCLUSION: BZF markedly suppresses the activity of rat anti-GBM crescentic glomerulonephritis. Fibrates might serve as a therapeutic option for crescentic glomerulonephritis.

Animals↗

PubMed2005

Effects of hormone deprivation and 2-methoxyestradiol combination therapy on hormone-dependent prostate cancer in vivo.

2-Methoxyestradiol (2-ME) has potent antiproliferative effects on cancer cells. Its utility alone or in combination with other therapies for treating prostate cancer, however, has not been fully explored. Androgen-dependent and independent human prostate cancer cells were examined in vivo for their response to combination therapy. Efficacy was assessed by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay and measuring microvessel density (MVD) in excised tumors. Animals harboring hormone-dependent tumors treated with 2-ME alone, androgen deprivation therapy alone, or the combination of the two had a 3.1-fold, 5.3-fold, and 10.1-fold increase in apoptosis, respectively. For hormone-independent tumors, treatment with 2-ME resulted in a 2.43-fold increase in apoptosis and a 73% decrease in MVD. 2-ME was most effective against hormone-dependent tumors in vivo and combination therapy resulted in a significant increase in efficacy compared to no treatment controls and trended toward greater efficacy than either 2-ME or androgen deprivation alone. Combination therapy should be investigated further as an additional therapeutic option for early prostate cancer.

2-Methoxyestradiol↗

PubMed2004

Application of RNA interference to chicken embryos using small interfering RNA.

Gene silencing using small interfering RNA (siRNA) is not established in avian species. The present study was performed to evaluate RNA interference (RNAi) in the chicken embryo by using a dual fluorescence reporter assay, a plasmid encoding green fluorescent protein (GFP) and a plasmid encoding red fluorescent protein (RFP). The siRNA targeting the GFP mRNA sequence (GFP-siRNA) with both plasmids was introduced into cultured cells and whole embryos by lipofection and microelectroporation, respectively. GFP- and RFP-expressed cells and embryos were observed under fluorescent microscopy and analyzed by flow cytometer, and their mRNAs were analyzed by reverse transcription-PCR (RT-PCR). The strong fluorescence was observed by introducing both plasmids into cells. The intensity of the green fluorescence generated by GFP was greatly suppressed by introducing GFP-siRNA. RT-PCR analysis showed that introducing GFP-siRNA also decreased GFP mRNA levels. In contrast to GFP, the intensity of the red fluorescence generated by RFP and the RFP mRNA levels remained unchanged. In whole embryos, also, introducing GFP-siRNA specifically suppressed GFP expression, and the suppression was maintained for at least 72 h. Consequently, it was concluded that the gene silencing using siRNA is applicable to analyzing the function of genes of interest during avian embryogenesis.

Animals↗

PubMed2004

Placenta percreta invading the urinary bladder.

INTRODUCTION: Placenta percreta is a rare obstetric complication causing life-threatening hemorrhage. CASE REPORT: The case of a woman with a placenta percreta invading the urinary bladder treated by cesarean hysterectomy and partial bladder resection is presented. Overall estimated blood loss was 11,130 ml, and 59 units of various blood products were transfused. CONCLUSION: Obstetricians and urologists should be aware of this rare condition.

Adult↗

PubMed2004

Evaluation of RNA interference in developing porcine granulosa cells using fluorescence reporter genes.

Gene silencing using small interfering RNA (siRNA) may be useful for functional analyses of unidentified genes expressed during cell differentiation. The present study was performed to evaluate RNA interference (RNAi) in porcine granulosa cells stimulated with bovine FSH, by using two fluorescence reporter genes: a plasmid encoding green fluorescent protein (GFP) and a plasmid encoding red fluorescent protein (RFP). The siRNA targeting GFP mRNA sequence (GFP-siRNA) with both plasmids was introduced into cultured cells by lipofection. GFP- and RFP-expressing cells were observed under fluorescence microscopy and analyzed by flow cytometry. Strong fluorescence was observed after introduction of both plasmids into cells. The intensity of green fluorescence generated by GFP was greatly suppressed by introduction of GFP-siRNA, showing an approximate 70% decrease in the ratio of green to red fluorescence. Consequently, we concluded that gene silencing by siRNA can be used to analyze the functions of genes of interest during differentiation of porcine granulosa cells.

Animals↗

PubMed2003

Interaction between ACE and ADD1 gene polymorphisms in the progression of IgA nephropathy in Japanese patients.

An interaction effect between the angiotensin-converting enzyme insertion/deletion (ACE I/D) and alpha-adducin (ADD1) Gly460Trp polymorphisms (G460W) on blood pressure regulation has recently been suggested, although its significance in the prognosis of renal function in IgA nephropathy (IgAN) has not been fully investigated. Therefore, we evaluated the clinical manifestations and renal prognosis in 276 Japanese patients with histologically proven IgAN with respect to their ACE I/D and ADD1 G460W polymorphisms. The prognosis of renal function was analyzed by Kaplan-Meier survival curves and multivariate Cox proportional-hazards regression models. Baseline data, including blood pressures, proteinuria, renal function, and incidence of hypertension, were similar for the different genotypes of ACE and ADD1. The individual genotypes taken alone were not associated with the progression of renal dysfunction. However, renal survival of patients with the 460WW polymorphism of ADD1 was significantly worse within the group with the II genotype of ACE (Kaplan-Meier, log rank test; chi2=6.062, P=0.0138) but not for those with other ACE genotypes. In the Cox proportional-hazards regression model with adjustment for clinical risk factors, including hypertension, proteinuria, and no administration of an angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, the 460WW variant of ADD1 was a highly significant and independent risk factor only for patients with the ACE II genotype, with a hazard ratio of 3.65 (P=0.0016), but not for those with other ACE genotypes (hazard ratio=0.65, P=0.2902). These findings suggest an interaction between ACE and ADD1 polymorphisms not only on blood pressure regulation but also on the progression of renal dysfunction in patients with IgAN.

Adult↗

PubMed2003

Expression of nitric oxide synthase-3 in porcine oocytes obtained at different follicular development.

The present study was designed to determine the localization of nitric oxide synthase-3 (NOS-3) in porcine follicles during follicular development. A 130-kDa NOS-3 protein was found with greater frequency much in the oocytes than in the cumulus cells, as revealed by Western blotting analysis. The content of NOS-3 in the oocyte was higher in large follicles (> 7-mm diameter) than in small follicles (< 2-mm). The data by Western blotting showed the same pattern as the observations obtained from the immunohistochemical studies, in which the periphery of the oocyte stained strong positive. The inner surface cell layer of granulosa cells and cumulus cells were positive staining, especially in large antral follicles. In the primordial follicles, NOS-3 was restricted to the cytoplasm of oocytes, and no stained product was observed in the nucleus of oocytes or granulosa cells. A significant synthesis of NO by oocytes was observed in the presence of ionomycin, but not in the absence of ionomycin, indicating that oocyte NOS-3 functions in response to transient elevations in the intracellular calcium level. We concluded that NOS-3 is expressed in the oocyte from the primordial follicular stage to antral follicular stage, and that it is functional at least in the antral follicles.

Animals↗

PubMed2003

Evaluation of deoxyribonuclease activity in seminal plasma of ejaculated chicken semen.

AIM: To confirm the stability of exogenous genes in the generation of transgenic chickens using ejaculated chicken sperm, the deoxyribonuclease (DNase) activity was evaluated in the seminal plasma of ejaculated semen and the stability of DNA was examined by adding lipofection reagents. METHODS: A PCR fragment (249 bp) of pEGFPN-1 vector was used as the DNA substrate and was incubated with the seminal plasma at 40 degree C for 30 min. Then, the whole reaction solution was subjected to agarose gel electrophoresis and the DNA size was evaluated under UV light. RESULTS: The DNA substrate was completely diminished after incubation with seminal plasma. However, the substrate was intact after incubation with heat-treated seminal plasma or incubation with seminal plasma in the presence of 0.5 mmol/L approximately 5 mmol/L EDTA. The substrate was stabilized in the seminal plasma by the addition of commercially available lipofection reagents. CONCLUSION: The DNase activity is present in the seminal plasma of ejaculated chicken semen. However, DNA is stable in the liposomal-DNA complex.

Animals↗

PubMed2002

Design and synthesis of peptide-based carboxylic acid-containing transition-state inhibitors of human neutrophil elastase.

In our search for a new agent, human neutrophil elastase (HNE) inhibitor, for the treatment of acute respiratory failure, we rationally designed and synthesized a series of peptide-based carboxylic acid-containing transition-state inhibitors. The presence of valyl moiety is found to be essential for potent in vitro inhibitory activity and also prevention of an undesirable toxicity. Of these, compound 9m has the most potent in vivo effect on HNE-induced lung hemorrhage in hamsters.

Amino Acids↗

PubMedDate not supplied

The transferrin receptor: a potential molecular imaging marker for human cancer.

Noninvasive imaging of differences between the molecular properties of cancer and normal tissue has the potential to enhance the detection of tumors. Because overexpression of endogenous transferrin receptor (TfR) has been qualitatively described for various cancers and is presumably due to malignant transformation of cells, TfR may represent a suitable target for application of molecular imaging technologies to increase detection of smaller tumors. In the work reported here, investigation into the biology of this receptor using electron microscopy has demonstrated that iron oxide particles targeted to TfR are internalized and accumulate in lysosomal vesicles within cells. Biochemical analysis of the interaction of imaging probes with cells overexpressing the TfR demonstrated that the extent of accumulation, and therefore probe efficacy, is dependent on the nature of the chemical cross-link between transferrin and the iron oxide particle. These data were utilized to design and synthesize an improved imaging probe. Experiments demonstrate that the novel magnetic resonance imaging (MRI) probe is sensitive enough to detect small differences in endogenous TfR expression in human cancer cell lines. Quantitative measurement of TfR overexpression in a panel of 27 human breast cancer patients demonstrated that 74% of patient cancer tissues overexpressed the TfR and that the sensitivity of the new imaging agent was suitable to detect TfR overexpression in greater than 40% of these cases. Based on a biochemical and cell biological approach, these studies have resulted in the synthesis and development of an improved MRI probe with the best in vitro and in vivo imaging properties reported to date.

Animals↗