Hemorragias cerebrales por anticoagulantes, ¿qué hacemos después?

El tractament antitrombòtic després d’una hemorragia intracerebral secundaria a tractament anticoagulant no està ben definit. Realitzem un estudi restropectiu per analitzar els riscos i beneficis de l’antiagregació vs anticoagulació. Evaluem 39 pacients, es va reiniciar l’anticoagulació en 25 i es va canviar a antiagregants a 14 pacients. Després d’un seguiment promig de 54 +/- 31 mesos, trobem que el tractament anticoagulant sembla augmentar el risc de nous events hemorràgics i la mortalitat, sense significació estadística. Son necessaris estudis prospectius per definir el millor tractament després de patir una hemorràgia cerebral per anticoagulants.

High proportion of wrongly identified methicillin-resistant Staphylococcus aureus carriers by use of a rapid commercial PCR assay due to presence of staphylococcal cassette chromosome element lacking the mecA gene.

During a 9-month period, 217 patients were newly diagnosed as methicillin-resistant Staphylococcus aureus (MRSA) carriers by using a commercial rapid PCR-based test (GeneXpert). However, no MRSA was recovered by culturing the second swab in 61 of these patients. Further analyses showed that 28 (12.9%) of the patients harbored S. aureus isolates with a staphylococcal cassette chromosome element lacking the mecA gene and were thus incorrectly determined to be MRSA carriers.

¿Qué ocurre con el déficit de vitamina d en la población general mayor de 65 años después del verano?

Estudi d’una cohort de persones majors de 64 anys ateses en 5 Àrees Bàsiques de Salut del Vallès Occidental, a les que es van determinar els nivells de vitamina D desprès de l’estiu, per analitzar la possible existència d’una variació estacional en el seu estat vitamínic, i els factors associats. Es van comparar els resultats amb les dades obtingudes en un estudi previ realitzat desprès de l’hivern. Es manté una elevada prevalença d’hipovitaminosi D en aquesta població desprès de l’estiu. Els factors associats amb la deficiència vitamínica van ser els nivells basals previs de 25(OH)D3 i la menor exposició solar.

Detection of hilA gene sequences in serovars of Salmonella enterica sufigbspecies enterica

hilA gene promoter, component of the Salmonella Pathogenicity Island 1, has been found in Salmonella serovar Typhimurium, being important for the regulation of type III secretion apparatus genes. We detected hilA gene sequences in Salmonella serovars Typhi, Enteritidis, Choleraesuis, Paratyphi A and B, and Pullorum, by polymerase chain reaction (PCR) and hybridization techniques. The primers to carry out PCR were designed according to hilA sequence. A low stringency hybridization with the probe pVV441 (hilA open-reading-frame plasmid) was carried out. To find hilA gene sequences in other Salmonella sp. suggest that these serovars could have similar sequences of this kind of virulence genes.

Mtp-40 and alpha antigen gene fragment amplification for the detection of Mycobacterium tuberculosis in Colombian clinical specimens

In this study, the use of Mtp-40 and alpha antigen polymerase chain reaction (PCR) amplification fragments for the precise tuberculosis (TB) diagnosis was evaluated. One hundred and ninety two different samples were obtained from 113 patients with suspected TB. Mtp-40 and alpha antigen protein genes were amplified by the PCR technique and compared to both the "gold standard" (culture) test, as well as the clinical parameters (including a clinical record and X-ray film exam in 113 patients). Thirty-eight of the 113 patients had a presumptive clinical diagnosis of TB; 74% being detected by PCR technique, 58% by culture and 44% by direct microscopic visualization. Weconclude that it is possible to use PCR as a suitable technique for the detection of any mycobacteria by means of the alpha antigen product, or the specific infection of Mycobacterium tuberculosis by means of the mtp-40 gene. This might be a good supporting tool in difficult clinical TB diagnosis and pauci-bacillary cases.

New insights into the long-term evolutionary history of the avian MHC

SummaryGene duplication and neofunctidnalization are important processes in the evolution of phenotypic complexity. They account for important evolutionary novelties that confer ecological adaptation, such as the major histocompatibility complex (MHC), a multigene family with a central role in vertebrates' adaptive immune system. Multigene families, which evolved in large part through duplication, represent promising systems to study the still strongly depbated relative roles of neutral and adaptive processes in the evolution of phenotypic complexity. Detailed knowledge on ecological function and a well-characterized evolutionary history place the mammals' MHC amongst ideal study systems. However mammalian MHCs usually encompass several million base pairs and hold a large number of functional and non-functional duplicate genes, which makes their study complex. Avian MHCs on the other hand are usually way more compact, but the reconstruction of. their evolutionary history has proven notoriously difficult. However, no focused attempt has been undertaken so far to study the avian MHC evolutionary history in a broad phylogenetic context and using adequate gene regions.In the present PhD, we were able to make important contributions to the understanding of the long-term evolution of the avian MHC class II Β (MHCI1B). First, we isolated and characterized MHCIIB genes in barn owl (Tyto alba?, Strigiformes, Tytonidae), a species from an avian lineage in which MHC has not been studied so far. Our results revealed that with only two functional MHCIIB genes the MHC organization of barn owl may be similar to the 'minimal essential' MHC of chicken (Gallus gallus), indicating that simple MHC organization may be ancestral to birds. Taking advantage of the sequence information from barn owl, we studied the evolution of MHCIIB genes in 13 additional species of 'typical' owls (Strigiformes, Strigidae). Phylogenetic analyses revealed that according to their function, in owls the peptide-binding region (PBR) encoding exon 2 and the non-PBR encoding exon 3 evolve by different patterns. Exon 2 exhibited an evolutionary history of positive selection and recombination, while exon 3 traced duplication history and revealed two paralogs evolving divergently from each other in owls, and in a shorebird, the great snipe {Gallinago media). The results from exon 3 were the first ever from birds to demonstrate gene orthology in species that diverged tens of millions of years ago, and strongly questioned whether the taxa studied before provided an adequate picture of avian MHC evolution. In a follow-up study, we aimed at explaining a striking pattern revealed by phylogenetic trees analyzing the owl sequences along with MHCIIB sequences from other birds: One owl paralog (termed DAB1) grouped with sequences of passerines and falcons, while the other (DAB2) grouped with wildfowl, penguins and birds of prey. This could be explained by either a duplication event preceding the evolution of these bird orders, or by convergent evolution of similar sequences in a number of orders. With extensive phylogenetic analyses we were able to show, that indeed a duplication event preceeded the major avian radiation -100 my ago, and that following this duplication, the paralogs evolved under positive selection. Furthermore, we showed that the divergently evolving amino acid residues in the MHCIIB-encoded β-chain potentially interact with the MHCI I α-chain, and that molecular coevolution of the interacting residues may have been involved in the divergent evolution of the MHCIIB paralogs.The findings of this PhD are of particular interest to the understanding of the evolutionary history of the avian MHC and, by providing essential information on long-term gene history in the avian MHC, open promising perspectives for advances in the understanding of the evolution of multigene families in general, and for avian MHC organization in particular. Amongst others I discuss the importance of including protein structure in the phylogenetic study of multigene families, and the roles of ecological versus molecular selection pressures. I conclude by providing a population genomic perspective on avian MHC, which may serve as a basis for future research to investigate the relative roles of neutral processes involving effective population size effects and of adaptation in the evolution of avian MHC diversity and organization.RésuméLa duplication de gènes et leur néo-fonctionnalisation sont des processus importants dans l'évolution de la complexité phénotypique. Ils sont impliqués dans l'apparition d'importantes nouveautés évolutives favorisant l'adaptation écologique, comme c'est le cas pour le complexe majeur d'histocompatibilité

Cis-acting elements, CArG-, E-, CCAAT- and TATA-boxes may be involved in sexually regulated gene transcription in Schistosoma mansoni

Schistosomes undergo various morphological and metabolic changes during their development, reflected in a finely tuned regulation of protein and/or gene expression. The mechanisms involved in the control of gene expression during the development of the parasite are not understood. Two actin genes had been previously cloned and observed to be differentially expressed during the maturation of the parasite. The SmAct gene contains four putative cis-regulatory elements (TATA-, CCAAT-, E- and CArG-boxes). Our objective was to investigate in greater detail the expression pattern of two actin genes and verify if the binding of nuclear proteins to the promoter elements of SmAct correlated with the expression profile observed. We detected little variation in the expression of actin genes during the first seven days of schistosomula culture in vitro. However, we observed significantly higher levels of expression in males compared to female adults. CArG and CCAAT elements bound to a greater extent and formed distinct complexes with male in comparison to female nuclear extracts. In contrast, female extracts bound weakly to the E-box probe while no binding was observed with male extracts. Taken together these results describe cis-acting elements that appear to be involved in sexually regulated gene expression in Schistosoma mansoni.

Optimization of the piggyBac Transposon Using mRNA and Insulators: Toward a More Reliable Gene Delivery System.

Integrating and expressing stably a transgene into the cellular genome remain major challenges for gene-based therapies and for bioproduction purposes. While transposon vectors mediate efficient transgene integration, expression may be limited by epigenetic silencing, and persistent transposase expression may mediate multiple transposition cycles. Here, we evaluated the delivery of the piggyBac transposase messenger RNA combined with genetically insulated transposons to isolate the transgene from neighboring regulatory elements and stabilize expression. A comparison of piggyBac transposase expression from messenger RNA and DNA vectors was carried out in terms of expression levels, transposition efficiency, transgene expression and genotoxic effects, in order to calibrate and secure the transposition-based delivery system. Messenger RNA reduced the persistence of the transposase to a narrow window, thus decreasing side effects such as superfluous genomic DNA cleavage. Both the CTF/NF1 and the D4Z4 insulators were found to mediate more efficient expression from a few transposition events. We conclude that the use of engineered piggyBac transposase mRNA and insulated transposons offer promising ways of improving the quality of the integration process and sustaining the expression of transposon vectors.

Per què Harry Potter i no Harriet Potter?

Les pel·lícules i sèries de ficció més vistes a Espanya durant el 2008 en clau de gènere.

Effects of four-week high-fructose diet on gene expression in skeletal muscle of healthy men.

AIMS: A high-fructose diet (HFrD) may play a role in the obesity and metabolic disorders epidemic. In rodents, HFrD leads to insulin resistance and ectopic lipid deposition. In healthy humans, a four-week HFrD alters lipid homoeostasis, but does not affect insulin sensitivity or intramyocellular lipids (IMCL). The aim of this study was to investigate whether fructose may induce early molecular changes in skeletal muscle prior to the development of whole-body insulin resistance. METHODS: Muscle biopsies were taken from five healthy men who had participated in a previous four-week HFrD study, during which insulin sensitivity (hyperinsulinaemic euglycaemic clamp), and intrahepatocellular lipids and IMCL were assessed before and after HFrD. The mRNA concentrations of 16 genes involved in lipid and carbohydrate metabolism were quantified before and after HFrD by real-time quantitative PCR. RESULTS: HFrD significantly (P<0.05) increased stearoyl-CoA desaturase-1 (SCD-1) (+50%). Glucose transporter-4 (GLUT-4) decreased by 27% and acetyl-CoA carboxylase-2 decreased by 48%. A trend toward decreased peroxisomal proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) was observed (-26%, P=0.06). All other genes showed no significant changes. CONCLUSION: HFrD led to alterations of SCD-1, GLUT-4 and PGC-1alpha, which may be early markers of insulin resistance.

The 245 kb amplified chromosome of Leishmania (V.) braziliensis contains a biopterin transporter gene

Leishmania (V.) braziliensis M2903 presents a small linear and stable 245 kb chromosome originating from a genomic amplification. Similar amplifications present in other species of Leishmania contain a gene coding for a biopterin transporter. Since Leishmania is auxotrophic for this metabolite, this amplification could result from the need to better capture biotpterin from growth media under specific circumstances. In this paper we show that this gene is also present in L. (V.) braziliensis small chromosome, which shares sequences with other genomic amplifications already described.

Ubiquitin-mediated protein degradation and methylation-induced gene silencing cooperate in the inactivation of the INK4/ARF locus in Burkitt lymphoma cell lines.

Burkitt lymphoma is one of the most aggressive tumors affecting humans. Together with the characteristic chromosomal translocation that constitutively activates the c-Myc oncogene, alterations in cellular tumor suppressor pathways are additionally required in order to allow the cells to overcome anti-oncogenic barriers and proliferate in an uncontrolled manner. The INK4a/ARF locus on chromosome 9p21 is considered a safeguard locus since it encodes the two important tumor suppressor proteins, p14 (ARF) and p16 (INK4a) . By regulating the p53 and Rb pathways p14 (ARF) and p16 (INK4a) respectively act as pro-apoptotic and cell cycle inhibitor proteins. The importance of the INK4a/ARF locus has been well documented in several human tumors as well as in Burkitt lymphoma. Although the mechanisms responsible for the transcriptional regulation of the INK4a/ARF locus have been thoroughly characterized, less is known about its posttranscriptional control. In this study we found that p16 (INK4a) and p14 (Arf) are concurrently inactivated in a panel of BL cell lines. We demonstrate that along with the epigenetic silencing of the p16INK4a gene, the complete inactivation of the locus is achieved by the improper turnover of INK4/ARF proteins by the ubiquitin-proteasome system (UPS), as the proteasome inhibitor MG-132 blocks p14 (ARF) degradation and induces a dramatic stabilization of the p16 (INK4a ) protein. We establish that the simultaneous deregulation of both DNA methylation patterns and the ubiquitin-dependent proteolysis system is required to completely inactive the INK4/ARF locus, opening new prospects for the understanding and treatment of Burkitt lymphoma.

Genetic and epigenetic analysis of SSAT gene dysregulation in suicidal behavior.

It has recently been proposed that the SSAT gene plays a role in the predisposition to suicidal behavior. SSAT expression was found to be down-regulated in the brain of suicide completers. In addition, a single nucleotide polymorphism (SNP) rs6526342 was associated both with variation in SSAT expression and with suicidal behavior. In this study, we aimed to characterize the relationship between SSAT dysregulation and suicide behavior. To this end, we measured SSAT expression levels in the ventral prefrontal cortex (VPFC) of suicide completers (n = 20) and controls (n = 20) and found them to be significantly down-regulated in suicide victims (P = 0.007). To identify the basis of the regulation of SSAT expression, we performed an association analysis of 309 SNPs with SSAT transcript levels in 53 lymphoblastoid cell lines from the CEPH collection. We then examined the methylation status of the SSAT promoter region in males and females suicide completers and control subjects whose SSAT brain expression had been measured. We found no evidence to support a role for SNPs in controlling the level of SSAT expression. SSAT promoter methylation levels were not different between suicide completers and controls and did not correlate with SSAT expression levels. In addition, we found no indication of a genetic association between suicidal behavior and SNPs located within the SSAT gene. Our study provides new results which show that dysregulation of SSAT expression does play a role in suicide behavior. However, our data do not support any association between rs6526342 and variation in SSAT expression or suicidal behavior.