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Hiraku Yoshida

Publications and source records attributed to Hiraku Yoshida.

8 recordsLinked to original sources
PubMed2006

Quantitative assessment of the peritoneal vessel density and vasculopathy in CAPD patients.

BACKGROUND: Peritoneal sclerosis (PS) complicates continuous ambulatory peritoneal dialysis (CAPD). Exploring the peritoneal vascular changes, which are characteristic histological findings in long-term PD, may give new insight into the basic pathological process leading to PS. We present a quantitative analysis of peritoneal vascular density as well as vasculopathy grades in relation to PD duration. METHODS: Peritoneal samples from 56 stable CAPD patients were analysed, and cases with membrane failure were excluded. Patients were classified into four groups according to CAPD duration in years: group A (n = 12), 0 year; group B (n = 11), 1-5 years; group C (n = 17), 5-9 years; and group D (n = 16), >9 years. The total density, of microvessels (capillaries, post-capillary venules and venules) and the density of each vasculopathy grade (0 = intact, 1 = mild, 2 = moderate and 3 = severe) in the compact zone were calculated (numbers/mm(2)) in each sample and the percentage ratio of each grade in relation to the total vessel density was also determined. RESULTS: There was no significant difference in the total vessel density (P-value = 0.64). In the grade of vasculopathy (density and percentage ratio), there were significant differences among groups, with grade 0 highest in group A, grade 1 highest in group C and grade 3 highest in group D. CONCLUSION: The results of this study indicate that vascular density does not increase, at least in stable uncomplicated PD, and that intact vessels decrease with time on PD, while the severe grades of vasculopathy predominate especially on a long-term basis.

Adult↗
PubMed2005

[The role of phosphatonin in phosphate metabolism].

PTH and active vitamin D are well known as classical phosphate regulating hormones. However, presence of some phosphaturic factors is assumed from investigations about TIO, XLH, ADHR. Those diseases cause hypophsophatemia, hyperphosphaturia, low vitamin D and rickets/ostepmalacia. FGF-23, which has been detected from TIO tumors, can induce hypophosphatemia by direct inhibition on phosphate reabsorption and by suppressing 1,25 (OH)(2)D(3) production through the inhibition of 25-hydroxyvitaminD 1alpha-hydroxylase, in the kidney. We have still other phosphatonin candidates such as MEPE, FRP4, etc. The role of these substances are not clear yet. Future investigations are required to clarify their roles in phosphate metabolism.

Fibroblast Growth Factor-23↗
PubMed2002

Plasma pteridine concentrations in patients with chronic renal failure.

BACKGROUND: Pteridine metabolism is impaired in the uraemic state. This may affect cardiovascular function and contribute to malnutrition. We wished to clarify further the impact of impaired pteridine metabolism. METHODS: Using the HPLC method, the plasma concentrations of endogenous pteridines were determined in 64 patients with chronic renal failure (33 on intermittent haemodialysis (HD) treatment vs 31 not yet on renal replacement therapy), and in 18 healthy controls. The patients were classified into three groups on the basis of creatinine clearance (Ccr): group (a), Ccr >60 ml/min; group (b), Ccr=10-60 ml/min; group (c), all patients receiving HD. RESULTS: Total neopterin (NP) and biopterin (BP) levels and the NP/BP ratio (a biomarker for macrophage activity) were significantly higher, whereas tetrahydrobiopterin (BH(4))/dihydrobiopterin (BH(2)) ratio (a biomarker for nitric oxide synthase and phenylalanine hydroxylase activities) was significantly lower in group (c) (118.9+/-11.7 ng/ml, 18.8+/-1.2 ng/ml, 6.79+/-0.53, and 0.26+/-0.06) than in healthy subjects (5.17+/-0.29 ng/ml, 2.83+/-0.19 ng/ml, 1.92+/-0.13, and 1.15+/-0.11; P<0.01). These significant differences were also observed between control and group (b) (12.4+/-2.20 ng/ml, 4.48+/-0.36 ng/ml, 2.81+/-0.48, and 0.74+/-0.08; P<0.01). In groups (a) and (b), significant negative correlations were found between Ccr and the total NP level (r=-0.663, P<0.01), the total BP level (r=-0.492, P<0.01), the BH(2) level (r=-0.677, P<0.01), and the NP/BP ratio (r=-0.493, P<0.01). Conversely, significant positive correlations were found between Ccr and the BH(4)/BH(2) ratio (r=0.602, P<0.01). CONCLUSION: The reduction of quinoid-type BH(2) to BH(4) is modified in patients with advanced chronic renal failure, before and after the initiation of regular HD treatment. These metabolic alterations may play a role in the impaired macrophage, endothelial constitutive nitric oxide synthase, or phenylalanine hydroxylase (PH) activities observed in such patients.

Biomarkers↗