Mutations of CLCN5 in Japanese children with idiopathic low molecular weight proteinuria, hypercalciuria and nephrocalcinosis

We designed the present study to examine the cross-sectional relation between age-related lens opacities and vitamin C supplement use over a 10-12-y period before assessment of lens status in women without diagnosed cataract or diabetes. This design avoids biased measurement of nutrient intake that results when knowledge of lens opacities influences nutrition-related behavior or its reporting. The participants were 247 Boston-area women aged 56-71 y selected from the Nurses' Health Study cohort with oversampling of women with high or low vitamin C intakes. Lens opacities were graded with the Lens Opacification Classification System II. Use of vitamin C supplements for > or = 10 y (n = 26) was associated with a 77% lower prevalence of early lens opacities (odds ratio: 0.23; 95% CI: 0.09, 0.60) at any lens site and a 83% lower prevalence of moderate lens opacities (odds ratio: 0.17; 95% CI: 0.03, 0.85) at any lens site compared with women who did not use vitamin C supplements (n = 141) after adjustment for age and other potentially confounding variables. Women who consumed vitamin C supplements for < 10 y showed no evidence of a reduced prevalence of early opacities. These data, together with data from earlier experimental and epidemiologic studies, suggest that long-term consumption of vitamin C supplements may substantially reduce the development of age-related lens opacities.     

Enhancement of human parainfluenza virus-induced cell fusion by pradimicin, a low molecular weight mannose-binding antibiotic

Oligosaccharides, especially mannose residues, expressed on the cell surface, are thought to be important for virus-induced membrane fusion. We examined the effect of mannose-binding compounds, pradimicin derivative BMY-28,864 (PRM) and concanavalin A (Con A), on cell fusion of human parainfluenza type 2 virus (hPIV2)-infected HeLa cells. Syncytium formation of hPIV2-infected HeLa cells was suppressed in the presence of Con A. On the other hand, PRM enhanced cell fusion of hPIV2-infected HeLa cells. These effects were blocked by addition of mannose-rich mannan. However, PRM shows little effect on virus growth and the expression of viral glycoproteins on the cell surface in hPIV2-infected HeLa cells. Fluorescein-isothiocyanate-labeled pradimicin and Con A bound to both uninfected and hPIV2-infected mononuclear cells, indicating that these compounds have an affinity to several cellular component(s). In contrast to Con A, PRM had little affinity to the viral glycoproteins. It is inferred from these results that the enhancement of hPIV2-induced cell fusion is probably due to the interaction between PRM and cellular component(s).     

Characterization of recombinant human fibroblast growth factor (FGF)-10 reveals functional similarities with keratinocyte growth factor (FGF-7)

A newly identified member of the fibroblast growth factor (FGF) family, designated FGF-10, is expressed during development and preferentially in adult lung. The predicted FGF-10 protein is most related to keratinocyte growth factor (KGF, or FGF-7). The latter is unique among FGFs in that it binds and signals only through the FGF receptor (FGFR2b) isoform KGF receptor (KGFR) expressed specifically by epithelial cells. In order to examine the biological and biochemical properties of human FGF-10, we isolated the cDNA and expressed its encoded protein in bacteria. The recombinant protein (rFGF-10) was a potent mitogen for Balb/MK mouse epidermal keratinocytes with activity detectable at 0.1 nM and maximal at around 5 nM. Within this concentration range, FGF-10 did not stimulate DNA synthesis in NIH/3T3 mouse fibroblasts. rFGF-10 bound the KGFR with high affinity comparable to that of KGF, and did not bind detectably to either the FGFR1c (Flg) or FGFR2c (Bek) receptor isoforms. The mitogenic activity of FGF-10 could be distinguished from that of KGF by its different sensitivity to heparin and lack of neutralization by a KGF monoclonal antibody. These results indicate that FGF-10 and KGF have similar receptor binding properties and target cell specificities, but are differentially regulated by components of the extracellular matrix.     

Intravenous pamidronate treatment in osteogenesis imperfecta

BACKGROUND: Astigmatic keratotomy is used conventionally to correct moderate surgical astigmatism. However, cases with very high surgical astigmatism due to wound compression can show a dramatic response to relaxing keratotomies made in the steeper meridian. The effect obtained cannot be predicted pre-operatively by using standard nomograms. METHODS: Coupled arcuate keratotomies combined with corneal valvular incisions were performed in a case of high astigmatism post-cataract surgery. RESULTS/CONCLUSION: Coupled arcuate keratotomies were combined with a corneal valvular incision enabled a surgical correction of nearly 9 D of astigmatism.     

Imipramine-induced inactivation of a cytochrome P450 2D enzyme in rat liver microsomes: in relation to covalent binding of its reactive intermediate

Preincubation of microsomes from male Wistar rats with imipramine (IMI) in the presence of NADPH caused a time-dependent loss of bunitrolol 4-hydroxylase activity, indicating that the CYP2D enzyme is inactivated during IMI metabolism, which has also been observed after in vivo administration of IMI. A similar effect was obtained when desipramine, an N-demethylated metabolite of IMI, was used as an inhibitor, whereas 2-hydroxy-IMI had no effect on the activity. Thus, it seems likely that the inactivation of the CYP2D enzyme is related to 2-hydroxylation process of IMI. Incubation of microsomes with [3H]IMI in the presence of NADPH resulted in covalent binding of a 3H-labeled material to microsomal protein. Formation rates of the reactive metabolites covalently bound to protein followed Michaelis-Menten kinetics, and the K(m) value (1.1 microM) was close to that for microsomal IMI 2-hydroxylation. The metabolism-dependent covalent binding of [3H]IMI was lower in Dark Agouti rats, which is an animal model of CYP2D deficiency, than in Wistar rats. The binding was inhibited by propranolol and quinidine, a substrate and an inhibitor of CYP2D, respectively, and by an antibody against CYP2D. Similar strain difference (Dark Agouti < Wistar) and inhibitory effects by the compounds and the antibody were observed in IMI 2-hydroxylase but not in N-demethylase activity. SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) of microsomal protein incubated with [3H]IMI and NADPH showed that the binding was prominent at the molecular mass of approximately 50 kDa, which would be consistent with the P450 protein being a target for the binding. Furthermore, proteins to which [3H]IMI metabolites covalently bound were immunoprecipitated with the anti-CYP2D antibody. These results suggest that IMI is biotransformed into a chemically reactive metabolite (probably arene-oxide) through its 2-hydroxylation step by the CYP2D enzyme in rat liver microsomes, and the metabolite binds covalently to the enzyme itself, resulting in the inactivation.     

Expression of structure-specific recognition protein mRNA in fetal kidney and Fe-nitrilotriacetate-induced renal carcinoma in the rat

Specific expression of the structure-specific recognition protein (SSRP) gene was investigated in rat fetal, adult, and tumor tissues using a 2.0-kb partial sequence of rat SSRP cDNA isolated from a cDNA library of rat renal cell carcinoma. The results revealed that it was rather specifically expressed in rat fetal kidney and renal cell carcinoma induced by Fenitrilotriacetate, but not in adult kidney, when various organs were tested by Northern blot analysis. In situ hybridization further demonstrated that it was located in the neoplastic cells of renal cell carcinoma and in the epithelial cells of fetal kidney but undetectable in any cells of normal adult kidney. These observations seem to imply the involvement of SSRP gene, which is believed to recognize structural alterations of DNA, in kidney development and carcinogenesis of certain types of kidney cancer.     

Molecular cloning of an isoform of Doc2 having two C2-like domains

We previously isolated a novel protein having two C2-like domains known to interact with Ca2+ and phospholipid, and named Doc2 (Double C2). Doc2 is predominantly expressed in brain and is implicated in Ca(2+)-dependent neurotransmitter release. We have isolated here an isoform of Doc2 and named the original one Doc2 alpha and the new one Doc2 beta. Doc2 beta alsp has two C2-like domains and is 61% identical to Doc2 alpha at the amino acid level. In contrast to Doc2 alpha, the Doc2 beta mRNA is expressed ubiquitously. These results indicate that there are at least two isoforms of Doc2, and suggest that Doc2 beta is involved in Ca(2+)-dependent intracellular vesicle trafficking in various types of cells.