西藏珞巴族的肤纹参数和聚类分析

本文报道了珞巴族正常人群的１２项肤纹参数．样本包括了１４２名男性和１９０名女性．参数与汉族及其他少数民族作了比较,用聚类分析法算出各民族间的距离,并绘制了聚类图．结果提示民族间的肤纹参数均有显著差异．     

Pathways mediating the nuclear import of histones H3 and H4 in yeast.

The correct assembly of chromatin is necessary for the maintenance of genomic stability in eukaryotic cells. A critical step in the assembly of new chromatin is the cell cycle-regulated synthesis and nuclear import of core histones. Here we demonstrate that the nuclear import pathway of histones H3 and H4 is mediated by at least two karyopherins/importins, Kap123p and Kap121p. Cytosolic H4 is found associated with Kap123p and H3. Kap121p is also present in the H4-PrA-associated fractions, albeit in lesser amounts than Kap123p, suggesting that this Kap serves as an additional import receptor. We further demonstrate that cytosolic Kap123p is associated with acetylated H3 and H4. H3 and H4 each contain a nuclear localization signal (NLS) in their amino-terminal domains. These amino-terminal domains were found to be essential for the nuclear accumulation of H3 and H4-green fluorescent protein reporters. Each NLS mediated direct binding to Kap123p and Kap121p, and decreased nuclear accumulation of H3 and H4 NLS-green fluorescent protein reporters was observed in specific kap mutant strains. H3 and H4 are the first histones to be assembled onto DNA, and these results show that their import is mediated by at least two import pathways.     

Acetyl-<Emphasis Type="SmallCaps">l</Emphasis>-Carnitine Attenuates Arsenic-Induced Oxidative Stress and Hippocampal Mitochondrial Dysfunction

Augmentation of mitochondrial oxidative stress through activating a series of deadly events has implicated as the main culprit of arsenic toxicity and therapeutic approaches based on improving mitochondrial function hold a great promise for attenuating the arsenic-induced toxicity. Acetyl-l-carnitine (ALC) through balancing the coenzyme A (CoA)/acyl-CoA ratio plays an important role in mitochondrial metabolism and thereby can help protect hippocampal neurons from oxidative damage. In the present study, we aimed to explore the effect of arsenic interactions on the mitochondrial function in the hippocampus of rats. Rats were randomly divided into five groups of control (distilled water), sodium arsenite (NaAsO₂, 20 mg/kg), and co-treatment of NaAsO₂ with various doses of ALC in three groups (100, 200, 300 mg/kg) and were treated orally for 21 consecutive days. Our results point out that arsenic exposure caused oxidative stress in rats’ hippocampus, which led to the reactive oxygen species (ROS) generation, mitochondrial swelling, the collapse of the mitochondrial membrane potential, and release of cytochrome c. It also altered Bcl-2/Bax expression ratio and increased caspase-3 and caspase-9 activities. Furthermore, arsenic exposure via activation of NF-κB and microglia increased inflammation. ALC could concentration-dependently counteract the arsenic-induced oxidative stress, modulate the antioxidant defense capacity, and improve mitochondrial functions. In addition, ALC decreased the expression of both death-associated proteins and of inflammatory markers. These findings indicate that ALC improved the arsenic-induced hippocampal mitochondrial dysfunction which underlines the importance of ALC in providing a possible therapeutic strategy for the prevention of arsenic-induced neurodegeneration.     

Join queries optimization in the distributed databases using a hybrid multi-objective algorithm

Cluster Computing - In the distributed database systems, the relations needed by a query can be kept in several locations. This process significantly increases potential corresponding Query...     

Inflammatory ocular adverse events with the use of oral bisphosphonates: a retrospective cohort study

Background:

There have been several published reports of inflammatory ocular adverse events, mainly uveitis and scleritis, among patients taking oral bisphosphonates. We examined the risk of these adverse events in a pharmacoepidemiologic cohort study.

Methods:

We conducted a retrospective cohort study involving residents of British Columbia who had visited an ophthalmologist from 2000 to 2007. Within the cohort, we identified all people who were first-time users of oral bisphosphonates and who were followed to the first inflammatory ocular adverse event, death, termination of insurance or the end of the study period. We defined an inflammatory ocular adverse event as scleritis or uveitis. We used a Cox proportional hazard model to determine the adjusted rate ratios. As a sensitivity analysis, we performed a propensity-score–adjusted analysis.

Results:

The cohort comprised 934 147 people, including 10 827 first-time users of bisphosphonates and 923 320 nonusers. The incidence rate among first-time users was 29/10 000 person-years for uveitis and 63/10 000 person-years for scleritis. In contrast, the incidence among people who did not use oral bisphosphonates was 20/10 000 person-years for uveitis and 36/10 000 for scleritis (number needed to harm: 1100 and 370, respectively). First-time users had an elevated risk of uveitis (adjusted relative risk [RR] 1.45, 95% confidence interval [CI] 1.25–1.68) and scleritis (adjusted RR 1.51, 95% CI 1.34–1.68). The rate ratio for the propensity-score–adjusted analysis did not change the results (uveitis: RR 1.50, 95% CI 1.29–1.73; scleritis: RR 1.53, 95% CI 1.39–1.70).

Interpretation:

People using oral bisphosphonates for the first time may be at a higher risk of scleritis and uveitis compared to people with no bisphosphonate use. Patients taking bisphosphonates must be familiar with the signs and symptoms of these conditions, so that they can immediately seek assessment by an ophthalmologist.Oral bisphosphonates are the most frequently prescribed class of medications for the prevention of osteoporosis. Most literature about the safety of bisphosphonates has mainly focused on long-term adverse events, including atypical fractures,¹ atrial fibrillation,² and esophageal and colon cancer.³Uveitis and scleritis are ocular inflammatory diseases that are associated with major morbidity. Anterior uveitis is the most common type of uveitis with an estimated 11.4–100.0 cases/100 000 person-years.^4,5 Both diseases require immediate treatment to prevent further complications, which may include cataracts, glaucoma, macular edema and scleral perforation. Numerous case reports and case series have described an association between the use of oral bisphosphonates and anterior uveitis^6–8 and scleritis.^8,9 In most reported cases, severe eye pain was reported within days of taking an oral bisphosphonates, and the symptom resolved after stopping the agent.^6,9 Only one large epidemiologic study has examined the association between the use of bisphosphonates and ocular inflammatory diseases.¹⁰ This study did not find an association, but it was limited by a small number of events and a lack of power. Thus, the association between uveitis or scleritis and the use of oral bisphosphonates is not fully known. Given that early intervention may prevent complications, we performed a pharmacoepidemiologic study to assess the true risk of these potentially serious conditions.     

Recessive hyperekplexia mutations of the glycine receptor α1 subunit affect cell surface integration and stability

The human neurological disorder hyperekplexia is frequently caused by recessive and dominant mutations of the glycine receptor α1 subunit gene, GLRA1 . Dominant forms are mostly attributed to amino acid substitutions within the ion pore or adjacent loops, resulting in altered channel properties. Here, the biogenesis of glycine receptor α1 subunit mutants underlying recessive forms of hyperekplexia was analyzed following recombinant expression in HEK293 cells. The α1 mutant S231R resulted in a decrease of surface integrated protein, consistent with reduced maximal current values. Decreased maximal currents shown for the recessive α1 mutant I244N were associated with protein instability, rather than decreased surface integration. The recessive mutants R252H and R392H encode exchanges of arginine residues delineating the intracellular faces of transmembrane domains. After expression, the mutant R252H was virtually absent from the cell surface, consistent with non-functionality and the importance of the positive charge for membrane integration. Surface expression of R392H was highly reduced, resulting in residual chloride conductance. Independent of the site of the mutation within the α1 polypeptide, metabolic radiolabelling and pulse chase studies revealed a shorter half-life of the full-length α1 protein for all recessive mutants as compared to the wild-type. Treatment with the proteasome blocker, lactacystin, significantly increased the accumulation of α1 mutants in intracellular membranes. These observations indicated that the recessive α1 mutants are recognized by the endoplasmatic reticulum control system, and degraded via the proteasome pathway. Thus, the lack of glycinergic inhibition associated with recessive hyperekplexia may be attributed to sequestration of mutant subunits within the endoplasmatic reticulum quality control system.