Genomic structure of three long QT syndrome genes: KVLQT1, HERG, and KCNE1

Long QT syndrome (LQT) is a cardiac disorder causing syncope and sudden death from arrhythmias. LQT is characterized by prolongation of the QT interval on electrocardiogram, an indicationof abnormal cardiac repolarization. Mutations in KVLQT1, HERG, SCN5A, and KCNE1, genes encoding cardiac ion channels, cause LQT. Here, we define thecomplete genomic structure of three LQT genesand use this information to identify disease-associated mutations. KVLQT1 is composed of 16 exonsand encompasses approximately 400 kb. HERG consists of 16 exons and spans 55 kb. Three exons make up KCNE1. Each intron of these genes contains the invariant GT and AG at the donor and acceptor splice sites, respectively. Intron sequences were used to design primer pairs for the amplification of all exons. Familial and sporadic cases affected bymutations in KVLQT1, HERG, and KCNE1 can nowbe genetically screened to identify individuals at risk of developing this disorder. This work has clinical implications for presymptomatic diagnosis and therapy.     

The HIV-1 envelope glycoproteins: fusogens, antigens, and immunogens

The human immunodeficiency virus-type 1 (HIV-1) envelope glycoproteins interact with receptors on the target cell and mediate virus entry by fusing the viral and cell membranes. The structure of the envelope glycoproteins has evolved to fulfill these functions while evading the neutralizing antibody response. An understanding of the viral strategies for immune evasion should guide attempts to improve the immunogenicity of the HIV-1 envelope glycoproteins and, ultimately, aid in HIV-1 vaccine development.     

Lightness, brightness, and brightness contrast: 1. Illuminance variation

Changes of annulus luminance in traditional disk-and-annulus patterns are perceptually ambiguous; they could be either reflectance or illuminance changes. In more complicated patterns, apparent reflectances are less ambiguous, letting us place test and standard patches on surrounds perceived to be different grays. Our subjects matched the apparent amounts of light coming from the patches (brightnesses), their apparent reflectances (lightnesses), or the brightness differences between the patches and their surrounds (brightness contrasts). The three criteria produced quantitatively different results. Brightness contrasts matched when the patch/surround luminance ratio of the test was approximately equal to that of the standard. Lightness matches were illumination invariant but were not exact reflectance matches; the different surrounds of test and standard produced a small illumination-invariant error. This constant error was negligible for increments, but, for decrements, it was approximately 1.5 Munsell value steps. Brightness matches covaried substantially with illuminance.     

Rules and procedures: October 1, 2001.

Describes and outlines the adoption and application of rules and procedures proposed by the Ethics Committee of the American Psychological Association. General provisions, processing and review of complaints, violations of the Ethics Code, and objectives and authority of the members of the Ethics Committee are included. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of specific fatty acids (8:0, 14:0, cis-18:1, trans-18:1) on plasma lipoproteins, early atherogenic potential, and LDL oxidative properties in the hamster

Although comparative studies of the cholesterolemic properties of trans fatty acids relative to cis-unsaturates and saturates have been conducted in humans and animals, there is no recent information relating these lipid responses to susceptibility to atherosclerosis. Therefore, hamsters were fed diets containing equivalent amounts of cholesterol (0.12% wt/wt) and test fats (20% wt/wt) for 8 weeks. Each test fat contained between 50-52% of the-total triacylglycerols as a single fatty acid, i.e., 8:0, 14:0, 18:0, cis-18:1, or trans-18:1 while the balance consisted of 16:0, cis-18:1 and 18:2 that were the same for all groups. Plasma total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C) levels were not different for 8:0, cis-18:1, and trans-18:1, whereas 14:0 caused a significant rise in plasma TC, LDL-C, and HDL-C. LDL oxidation measurements showed that the lag phase of conjugated diene formation was longest for the trans-18:1 and cis-18:1 groups while rate of conjugated diene formation was lowest for the trans-18:1 and cis-18:1 groups. The trans-18:1- and cis-18:1-fed animals had significantly higher levels of LDL alpha-tocopherol relative to the 8:0- and 14:0-fed animals. Aortic fatty streak formation was highest for the 14:0- and 8:0-fed animals and lowest for the trans-18:1. In conclusion, the plasma lipid and antioxidant properties of trans-18:1 and cis-18:1 were comparable while the trans-18:1-fed hamsters had the least amount of early atherosclerosis. In addition, 8:0-fed animals unexpectedly had early atherosclerosis formation similar to the 14:0-fed animals.     

1-Thiomethoxsalen and 1-thiopsoralen: synthesis, photobiological properties, and site specific reaction of thiopsoralens with DNA

The sulfur analogues of psoralen and 8-methoxypsoralen (8-MOP) in the pyrone moiety were synthesized and compared to the parent compounds in terms of photoreactivity with viral M13mp19 RF DNA. The damaged viral DNA was transfected into Escherichia coli and scored for infectivity toward Ca-treated wild-type E. coli. This allowed a comparative study of the sulfur and oxygen analogues to be made in terms of photoreactivity. Furthermore, the DNA sequence specificity for the formation of monoadducts and cross-links of the four analogues was determined with 32P-labeled oligonucleotides containing thymidine in different sequences. The most site specific of the studied psoralens is 8-MOP, while 1-thiopsoralen is the most reactive analogue. This new thio analogue of psoralen leads to the efficient formation of monoadducts and cross-links in any pyrimidine-purine site.     

New NSAIDS: COX-1, COX-2, what about them?

Non steroidal antiinflammatory (NSAID) drugs are the most widely prescribed drugs against pain and inflammation. Problems of tolerance, particularly gastrointestinal toxicity, limit their use. The central mechanism of NSAID action is the reduction of prostaglandin production from arachidonic acid through cyclooxygenase inhibition. Although such a mechanism was already described 25 years ago, the recent discovery of two isoforms of cyclooxygenase, the cyclooxygenase 1 (COX-1) constitutively expressed in most tissues and the cyclooxygenase 2 (COX-2), inducible, has prompted research in developing new NSAID that would be safer whilst maintaining their efficacy. Nevertheless, their long term efficacy and safety need to be demonstrated in clinical practice. There are still unsolved questions, especially about the physiological role of COX-2.     

Polyunsaturated fatty acids, Part 1: Occurrence, biological activities and applications

Polyunsaturated fatty acids form a unique class of food constituents that show a wide range of functions in biological systems. Investigations over the past two decades have uncovered their roles and those of their eicosanoid metabolites, and have highlighted their homeostatic functions in mammals. A growing number of common human medical conditions are thought to be traceable to dysfunctions in the eicosanoid system, which could in turn be due to imbalances in the intake and/or metabolism of polyunsaturated fatty acids. This, together with medical advances, has spurred the introduction of biomedical products, nutritionals, fortified foods and health supplements.     

Three new DP alleles identified in sub-Saharan Africa: DPB1*7401, DPA1*02013, and DPA1*0302

PURPOSE: To investigate the presence of Human Leukocyte Antigens (HLA) in organ cultured corneas, in lyophilised epikeratophakia lenticules prepared by dry state lathing, and in lenticules subjected to prolonged rehydration in Balanced Salt Solution (BSS). METHODS: Twelve lenticules and 3 organ cultured corneas were studied for the presence of HLA-ABC (class I), and HLA-DR, -DQ, and -DP (class II), antigens using the immunoperoxidase technique. RESULTS: HLA-ABC antigens were detected in all lenticules. HLA-DR antigen was also detected in low concentrations in 6 out of 12 lenticules. HLA-DQ and -DP antigens were generally absent. Incubation in BSS for 24 and 48 hours did not change the expression of antigens. CONCLUSIONS: HLA-class I, and to some degree HLA-class II antigens, are present in the stroma of both organ cultured corneas, and in lyophilised lenticules. Incubation in BSS for up to 48 hours did not reduce the expression of antigens.     

Antithrombotic effects of 3-([1:1',2':1"]-3'-terphenyl)propanol in animals

3-([1:1',2':1"]-3'-Terphenyl)propanol (CAS 186835-06-3, F050) and acetylsalicylic acid (ASA) inhibited platelet aggregation induced by CaCl2, arachidonic acid, collagen, adenosine diphosphate (ADP) and thrombin in guinea pigs, rabbits and rats in vitro. However, F050 had a wider spectrum of actions than ASA. Orally administered F050 inhibited platelet aggregation ex vivo. F050 significantly reduced the thrombus formation in the extracorporeal circulation thrombosis model in guinea pigs. It inhibited erythrocyte hemolysis induced by hypotonic NaCl, while ASA did not. F050, but not ASA, inhibited increases in platelet [CA2+]i caused by thrombin in guinea pigs. F050 is a parent compound that will facilitate the development of an orally active drug for the treatment of thrombotic diseases.     

HIV-1 Nef protein: purification, crystallizations, and preliminary X-ray diffraction studies

Human immunodeficiency virus Nef protein accelerates virulent progression of AIDS by its interaction with specific cellular proteins involved in cellular activation and signal transduction. Here we report the purification and crystallization of the conserved core of HIV-1LAI Nef protein in the unliganded form and in complex with the wild-type SH3 domain of the P59fyn protein-tyrosine kinase. One-dimensional NMR experiments show that full-length protein and truncated fragment corresponding to the product of HIV-1 protease cleavage have a well-folded compact tertiary structure. The ligand-free HIV-1 Nefcore protein forms cubic crystals belonging to space group P23 with unit cell dimensions of a = b = c = 86.4 A. The Nef-Fyn SH3 cocrystals belong to the space group P6(1)22 or its enantiomorph, P6(5)22, with unit cell dimensions of a = b = 108.2 A and c = 223.7 A. Both crystal forms diffract to a resolution limit of 3.0 A resolution using synchrotron radiation, and are thus suitable for X-ray structure determination.     

Self-association of the single-KH-domain family members Sam68, GRP33, GLD-1, and Qk1: role of the KH domain

Sam68 is a member of a growing family of proteins that contain a single KH domain embedded in a larger conserved domain of approximately 170 amino acids. Loops 1 and 4 of this KH domain family are longer than the corresponding loops in other KH domains and contain conserved residues. KH domains are protein motifs that are involved in RNA binding and are often present in multiple copies. Here we demonstrate by coimmunoprecipitation studies that Sam68 self-associated and that cellular RNA was required for the association. Deletion studies demonstrated that the Sam68 KH domain loops 1 and 4 were required for self-association. The Sam68 interaction was also observed in Saccharomyces cerevisiae by the two-hybrid system. In situ chemical cross-linking studies in mammalian cells demonstrated that Sam68 oligomerized in vivo. These Sam68 complexes bound homopolymeric RNA and the SH3 domains of p59fyn and phospholipase Cgamma1 in vitro, demonstrating that Sam68 associates with RNA and signaling molecules as a multimer. The formation of the Sam68 complex was inhibited by p59fyn, suggesting that tyrosine phosphorylation regulates Sam68 oligomerization. Other Sam68 family members including Artemia salina GRP33, Caenorhabditis elegans GLD-1, and mouse Qk1 also oligomerized. In addition, Sam68, GRP33, GLD-1, and Qk1 associated with other KH domain proteins such as Bicaudal C. These observations indicate that the single KH domain found in the Sam68 family, in addition to mediating protein-RNA interactions, mediates protein-protein interactions.     

Lipid prodrugs of phosphonoacids: greatly enhanced antiviral activity of 1-O-octadecyl-sn-glycero-3-phosphonoformate in HIV-1, HSV-1 and HCMV-infected cells, in vitro

Phosphonoformate (PFA) effectively inhibits viral polymerases but is relatively ineffective in virus-infected cells in tissue culture. A lipid prodrug of phosphonoformate was synthesized by coupling the phosphonate residue of phosphonoformate to the sn-3 hydroxyl of 1-O-octadecyl-sn-glycerol. This prodrug, 1-O-octadecyl-sn-glycero-3-phosphonoformate (ODG-PFA), was 93-fold more active than phosphonoformate in cells infected with the AD169 strain of cytomegalovirus (CMV), and 111-147-fold more active in cells infected with three human clinical isolates of CMV. The compound was also 44-fold more active in human immunodeficiency virus-1 (HIV-1) infected cells and 43-fold more active in cells infected with herpes simplex virus (HSV). Studies of the mechanisms of increased antiviral activity indicate that 1-O-octadecyl-sn-glycero-3-[14C]phosphonoformate is taken up more extensively than the free drug by the host MRC-5 human lung fibroblasts. Intracellular enzymes convert 1-O-octadecyl-sn-glycero-3-phosphonoformate to phosphonoformate. This conversion does not occur in the tissue culture medium containing fetal bovine serum (FBS) or in MRC-5-conditioned medium. In view of its greatly increased in vitro potency and selectivity, 1-O-octadecyl-sn-glycero-3-phosphonoformate may be useful in treating viral diseases.