Cultured subventricular zone progenitor cells transduced with neurogenin-2 become mature glutamatergic neurons and integrate into the dentate gyrus.

We have previously shown that transplantation of immature DCX+/NeuN+/Prox1+ neurons (found in the neonatal DG), but not undifferentiated neuronal progenitor cells (NPCs) from ventral subventricular zone (SVZ), results in neuronal maturation in vivo within the dentate niche. Here we investigated whether we could enhance the integration of SVZ NPCs by forced expression of the proneural gene Neurogenin 2 (NEUROG2). NPCs cultured from neonatal GFP-transgenic rat SVZ for 7 days in a non-differentiating medium were transduced with a retrovirus encoding NEUROG2 and DsRed or the DsRed reporter gene alone (control). By 3 days post-transduction, the NEUROG2-transduced cells maintained in culture contained mostly immature neurons (91% DCX+; 76% NeuN+), whereas the control virus-transduced cells remained largely undifferentiated (30% DCX+; <1% NeuN+). At 6 weeks following transplantation into the DG of adult male rats, there were no neurons among the transplanted cells treated with the control virus but the majority of the NEUROG2-transduced DsRed+ SVZ cells became mature neurons (92% NeuN+; DCX-negative). Although the NEUROG2-transduced SVZ cells did not express the dentate granule neuron marker Prox1, most of the NEUROG2-transduced SVZ cells (78%) expressed the glutamatergic marker Tbr1, suggesting the acquisition of a glutamatergic phenotype. Moreover, some neurons extended dendrites into the molecular layer, grew axons containing Ankyrin G+ axonal initial segments, and projected into the CA3 region, thus resembling mature DG granule neurons. A proportion of NEUROG2 transduced cells also expressed c-Fos and P-CREB, two markers of neuronal activation. We conclude that NEUROG2-transduction is sufficient to promote neuronal maturation and integration of transplanted NPCs from SVZ into the DG.This is the final version of the article. It was published by PLOS in PLOS One and can be found here: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031547

New Salivary Biomarkers of Human Exposure to Malaria Vector Bites

International audienc

8-Bromo­naphthalen-1-amine

The title compound, C10H8BrN, was obtained by slow addition of sodium azide to 8-bromo-1-naphthoic acid, followed by addition of aqueous ammonia. The crude product was crystallized from petroleum ether to give pink crystals. Compared to other 1,8-disubstituted naphthalene compounds, this compound exhibits less strain between the 1 and 8 substituents. Additionally, the NH protons form both intra- and inter­molecular hydrogen bonds. The naphthalene units are arranged in a herring-bone stacking motif

Oral bacteria in infective endocarditis requiring surgery: a retrospective analysis of 134 patients.

OBJECTIVES It has been reported that bacteria associated with infective endocarditis originate from the oral cavity in 26-45% of cases. However, little is known on the counts and species of periodontal microbiota in infected heart valves. The aim of this study was to identify these aspects of periodontal microbiota in infective endocarditis and to potentially initiate a dental extraction concept for periodontally compromised teeth concerning patients requiring heart valve surgery. MATERIALS AND METHODS The retrospective study group consisted of tissue samples from infected heart valves of 683 patients who had undergone heart valve surgery. Before patients had undergone cardiac surgery, the following laboratory tests confirmed the occurrence of endocarditis in all patients: blood cultures, echocardiography, electrocardiography, chest X-ray, and electrophoresis of the serum proteins. The specimens were aseptically obtained and deep frozen immediately following surgery. Microbiological diagnosis included proof of germs (dichotomous), species of germs, and source of germs (oral versus other). RESULTS Microbiota was detected in 134 (31.2%) out of 430 enrolled patients. Oral cavity was supposed to be the source in 10.4% of cases, whereas microbiota of the skin (57.5%) and gastrointestinal tract (GIT, 24.6%) were detected considerably more frequently. Moreover, periodontal bacteria belonged mostly to the Streptococci species and the yellow complex. None of the detected bacteria belonged to the red complex. CONCLUSION Most frequently, the skin and GIT represented the site of origin of the microbiota. Nevertheless, the oral cavity represented the source of IE in up to 10%. Consequently, it needs to be emphasized that a good level of oral hygiene is strongly recommended in all patients undergoing heart valve surgery in order to reduce the bacterial load in the oral cavity, thereby minimizing the hematogenous spread of oral microbiota. The prerequisites for conservative dental treatment versus radical tooth extraction must always be based on the patient's cooperation, and the clinical intraoral status on a sense of proportion in view of the overall clinical situation due to the underlying cardiac disease. CLINICAL RELEVANCE The oral cavity is a source of oral microbiota on infected heart valves. Patients requiring heart valve surgery should always undergo a critical evaluation of dental treatment affecting periodontally compromised teeth, favoring a systematic, conservative-leaning recall

Two complement receptor one alleles have opposing associations with cerebral malaria and interact with α+thalassaemia

Malaria has been a major driving force in the evolution of the human genome. In sub-Saharan African populations, two neighbouring polymorphisms in the Complement Receptor One (CR1) gene, named Sl2 and McCb, occur at high frequencies, suggesting selection by malaria. Previous studies have been inconclusive. Using a large case-control study of severe malaria in Kenyan children and statistical models adjusted for confounders, we demonstrate that Sl2 and McCb have opposing malaria associations. The Sl2 polymorphism is associated with markedly reduced odds of cerebral malaria and death, while the McCb polymorphism is associated with increased odds of cerebral malaria. We also identified an unexpected interaction between Sl2 and α+thalassaemia, revealing that the protective association of Sl2 was greatest in children with normal α-globin. The complex relationship between these three mutations may explain previous conflicting findings, and the data highlight the importance of considering genetic interactions in disease-association studies

Cross-talk between two nucleotide-signaling pathways in Staphylococcus aureus.

Nucleotide-signaling pathways are found in all kingdoms of life and are utilized to coordinate a rapid response to external stimuli. The stringent response alarmones guanosine tetra- (ppGpp) and pentaphosphate (pppGpp) control a global response allowing cells to adapt to starvation conditions such as amino acid depletion. One more recently discovered signaling nucleotide is the secondary messenger cyclic diadenosine monophosphate (c-di-AMP). Here, we demonstrate that this signaling nucleotide is essential for the growth of Staphylococcus aureus, and its increased production during late growth phases indicates that c-di-AMP controls processes that are important for the survival of cells in stationary phase. By examining the transcriptional profile of cells with high levels of c-di-AMP, we reveal a significant overlap with a stringent response transcription signature. Examination of the intracellular nucleotide levels under stress conditions provides further evidence that high levels of c-di-AMP lead to an activation of the stringent response through a RelA/SpoT homologue (RSH) enzyme-dependent increase in the (p)ppGpp levels. This activation is shown to be indirect as c-di-AMP does not interact directly with the RSH protein. Our data extend this interconnection further by showing that the S. aureus c-di-AMP phosphodiesterase enzyme GdpP is inhibited in a dose-dependent manner by ppGpp, which itself is not a substrate for this enzyme. Altogether, these findings add a new layer of complexity to our understanding of nucleotide signaling in bacteria as they highlight intricate interconnections between different nucleotide-signaling networks

Origin of Minority Drug-Resistant HIV-1 Variants in Primary HIV-1 Infection

Background. Drug-resistant human immunodeficiency virus type 1 (HIV-1) minority variants (MVs) are present in some antiretroviral therapy (ART)-naive patients. They may result from de novo mutagenesis or transmission. To date, the latter has not been proven. Methods. MVs were quantified by allele-specific polymerase chain reaction in 204 acute or recent seroconverters from the Zurich Primary HIV Infection study and 382 ART-naive, chronically infected patients. Phylogenetic analyses identified transmission clusters. Results. Three lines of evidence were observed in support of transmission of MVs. First, potential transmitters were identified for 12 of 16 acute or recent seroconverters harboring M184V MVs. These variants were also detected in plasma and/or peripheral blood mononuclear cells at the estimated time of transmission in 3 of 4 potential transmitters who experienced virological failure accompanied by the selection of the M184V mutation before transmission. Second, prevalence between MVs harboring the frequent mutation M184V and the particularly uncommon integrase mutation N155H differed highly significantly in acute or recent seroconverters (8.2% vs 0.5%; P < .001). Third, the prevalence of less-fit M184V MVs is significantly higher in acutely or recently than in chronically HIV-1-infected patients (8.2% vs 2.5%; P = .004). Conclusions. Drug-resistant HIV-1 MVs can be transmitted. To what extent the origin—transmission vs sporadic appearance—of these variants determines their impact on ART needs to be further explore

Trajectories of body weight change and survival among patients with mCRC treated with systemic therapy: Pooled analysis from the ARCAD database

Background Higher body mass index is associated with a higher incidence of colorectal cancer (CRC) but also with improved survival in metastatic CRC (mCRC). Whether weight change after mCRC diagnosis is associated with survival remains largely unknown. Methods We analysed individual patient data for previously untreated patients enrolled in five phase 3 randomised trials conducted between 1998 and 2006. Weight measurements were prospectively collected at baseline and up to 59.4 months after diagnosis. We used stratified multivariable Cox models to assess the prognostic associations of weight loss with overall and progression-free survival, adjusting for other factors. The primary end-point was a difference in overall survival (OS) between populations with weight loss and stable or increasing weight. Findings Data were available for 3504 patients. The median weight change at 3 months was −0.54% (IQR −3.9 … +1.5%). We identified a linear trend of increasing risk of death associated with progressive weight loss. Unstratified median OS was 20.5, 18.0, and 11.9 months (p < 0.001) for stable weight or gain, <5% weight loss, and ≥5% weight loss at 3 months, respectively. Weight loss was associated with a higher risk of death (<5% loss: aHR 1.18 [1.06–1.30], p < 0.002; ≥5% loss: aHR 1.87 [1.67–2.1], p < 0.001) as compared to stable or increasing weight at 3 months post-baseline (reference), while adjusting for age, sex, performance, and a number of metastatic sites. Interpretation Patients losing weight during systemic therapy for metastatic colorectal cancer have significantly shorter OS. The degree of weight loss is proportional to the observed increased risk of death and remains evident among underweight, normal weight, and obese individuals. On-treatment weight change could be used as an intermediate end-point