Prolyl and lysyl hydroxylases in collagen synthesis

Collagens are the most abundant proteins in the extracellular matrix. They provide a framework to build organs and tissues and give structural support to make them resistant to mechanical load and forces. Several intra‐ and extracellular modifications are needed to make functional collagen molecules, intracellular post‐translational modifications of proline and lysine residues having key roles in this. In this article, we provide a review on the enzymes responsible for the proline and lysine modifications, that is collagen prolyl 4‐hydroxylases, 3‐hydroxylases and lysyl hydroxylases, and discuss their biological functions and involvement in diseases.     

The proteome microenvironment determines the protective effect of preconditioning in cisplatin-induced acute kidney injury

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Neurological disorders and violence: a systematic review and meta-analysis with a focus on epilepsy and traumatic brain injury

The objectives of this study were to systematically review and meta-analyze the research literature on the association of common neurological disorders and violence. Keywords relating to neurological disorders and violence were searched between 1966 and August 2008. Case–control and cohort studies were selected. Odds ratios of violence risk in particular disorders compared with controls were combined using fixed-effects meta-analysis with the data presented in forest plots. Sensitivity analyses were conducted to identify possible differences in risk estimates across surveys. Information on risk factors for violence was extracted if replicated in more than one study. Nine studies were identified that compared the risk of violence in epilepsy or traumatic brain injury compared with unaffected controls. For the epilepsy studies, the overall pooled odds ratio for violent outcomes was 0.67 [95% confidence interval (CI) 0.46–0.96]. For traumatic brain injury, the odds ratio was 1.66 (95% CI 1.12–2.31). An additional 11 case–control studies investigated factors associated with violence in epilepsy and traumatic brain injury. It was not possible to meta-analyze these data. Comorbid psychopathology was associated with violence. Data on other neurological conditions was limited and unreplicated. In conclusion, although the evidence was limited and methodological quality varied, epilepsy and traumatic brain injury appeared to differ in their risk of violence compared with control populations. Longitudinal studies are required to replicate this review’s provisional findings that epilepsy is inversely associated with violence and that brain injury modestly increases the risk, and further research is needed to provide information on a broader range of risk factors.     

Biochemical, immunological, and immunocytochemical evidence for the association of chalcone synthase with endoplasmic reticulum membranes.

Chalcone synthase [naringenin-chalcone synthase; malonyl-CoA:4-coumaroyl-CoA malonyltransferase (cyclizing), E.C. 2.3.1.74], the key enzyme of flavonoid pathways that was believed to be soluble, has been localized on ribosome-bearing endoplasmic reticulum membranes in the epidermis of buckwheat (Fagopyrum esculentum M.) hypocotyls. Enzyme activity measurement and immunoblots of buckwheat hypocotyl homogenates that were fractionated on linear sucrose density gradients and developed with a specific chalcone synthase antibody and a 20-nm ImmunoGold conjugate showed the presence of chalcone synthase in fractions enriched in endoplasmic reticulum membranes. The presence of chalcone synthase on these membranes was not caused by nonspecific adsorption or entrapment of proteins. Immunocytochemical investigations with both a 5-nm and a 20-nm ImmunoGold conjugate showed that chalcone synthase was associated with the cytoplasmic face of rough (ribosome bearing) endoplasmic reticulum membranes. Plasma membrane, nucleus, plastids, mitochondria, golgi, and the tonoplast were not labeled. These data are consistent with our earlier described model suggesting that the synthesis of phenylpropanoids and flavonoids takes place partially or fully on membrane-associated enzyme complexes.     

The Sperm Acrosome: Immunological Analysis using Specific Polyclonal and Monoclonal Antibodies Directed Against the Outer Acrosomal Membrane of Boar Spermatozoa

An antiserum to the purified porcine outer acrosomal membrane (OAM) was raised in female Balb/c mice and was characterized by means of an indirect ELISA. The hyperimmune serum reacted selectively with the acrosomal cap of the sperm head and showed an extremely good cross reactivity with bull and human spermatozoa when assayed by indirect immunofluorescence. Immunoelectron microscopy using the protein A-gold method further confirmed the specificity of the anti-OAM-antiserum for the OAM. In an effort to identify the OAM antigens recognized by the hyperimmune serum and to analyse the extent of cross reactivity on a molecular level, the SDS-extractable proteins were separated by SDS-PAGE, transblotted and immunoprinted using an 125J-conjugated anti-mouse-antibody. To facilitate functional and structural analysis of distinct OAM-proteins monoclonal antibodies were generated by hybridization of mouse myeloma cells with the splenocytes of female Balb/c mice immunized with the purified OAM. One fusion resulted in about 100 anti-OAM-antibodies secreting hybridoma cultures, of which about 30% showed cross reaction with human and bull spermatozoa. Four stable cell lines were selected for this study secreting antibodies directed against the outer acrosomal membrane of boar spermatozoa. Whereas the polyclonal immune mouse serum stained the entire acrosomal cap, the four hybridoma antibodies generated a patch-work-like immunofluorescence pattern over the acrosome. HPLC-ELISA of the solubilized OAM revealed first information on the nature of the corresponding membrane antigen.     

Hyperphosphataemia and related mortality.

Sir, With great interest we read the editorial review of Jean etal. [1] on the relationship between hyperphosphataemia and mortalityin end-stage renal disease patients. The authors summarize resultsfrom the large USRDS and DOPPS studies in which associationsof hyperphosphataemia and increased mortality risks were