The midgut epithelium of mosquitoes adjusts cell proliferation and endoreplication to respond to physiological challenges.

BACKGROUND: Hematophagous mosquitoes transmit many pathogens that cause human diseases. Pathogen acquisition and transmission occur when female mosquitoes blood feed to acquire nutrients for reproduction. The midgut epithelium of mosquitoes serves as the point of entry for transmissible viruses and parasites. RESULTS: We studied midgut epithelial dynamics in five major mosquito vector species by quantifying PH3-positive cells (indicative of mitotic proliferation), the incorporation of nucleotide analogs (indicative of DNA synthesis accompanying proliferation and/or endoreplication), and the ploidy (by flow cytometry) of cell populations in the posterior midgut epithelium of adult females. Our results show that the epithelial dynamics of post-emergence maturation and of mature sugar-fed guts were similar in members of the Aedes, Culex, and Anopheles genera. In the first three days post-emergence, ~ 20% of cells in the posterior midgut region of interest incorporated nucleotide analogs, concurrent with both proliferative activity and a broad shift toward higher ploidy. In mature mosquitoes maintained on sugar, an average of 3.5% of cells in the posterior midgut region of interest incorporated nucleotide analogs from five to eight days post-emergence, with a consistent presence of mitotic cells indicating constant cell turnover. Oral bacterial infection triggered a sharp increase in mitosis and nucleotide analog incorporation, suggesting that the mosquito midgut undergoes accelerated cellular turnover in response to damage. Finally, blood feeding resulted in an increase in cell proliferation, but the nature and intensity of the response varied by mosquito species and by blood source (human, bovine, avian or artificial). In An. gambiae, enterocytes appeared to reenter the cell cycle to increase ploidy after consuming blood from all sources except avian. CONCLUSIONS: We saw that epithelial proliferation, differentiation, and endoreplication reshape the blood-fed gut to increase ploidy, possibly to facilitate increased metabolic activity. Our results highlight the plasticity of the midgut epithelium in mosquitoes' physiological responses to distinct challenges.

Fourier transform spectrometer based on high-repetition-rate mid-infrared supercontinuum sources for trace gas detection.

We present a fast-scanning Fourier transform spectrometer (FTS) in combination with high-repetition-rate mid-infrared supercontinuum sources, covering a wavelength range of 2-10.5 µm. We demonstrate the performance of the spectrometer for trace gas detection and compare various detection methods: baseband detection with a single photodetector, baseband balanced detection, and synchronous demodulation at the repetition rate of the supercontinuum source. The FTS uses off-the-shelf optical components and provides a minimum spectral resolution of 750 MHz. It achieves a noise equivalent absorption sensitivity of ∼10-6 cm-1 Hz-1/2 per spectral element, by using a 31.2 m multipass absorption cell.

Great saphenous vein ablation with steam injection: results of a multicentre study.

OBJECTIVE: To assess the safety and efficiency of steam vein sclerosis (SVS) of the great saphenous vein (GSV) in a multicentre open prospective cohort study. DESIGN: 75 consecutive adult patients with GSV reflux, CEAP C2-C5 and vein diameter 4-13 mm. METHODS: Patients treated using an SVS™ generator delivering homogenous pulses of superheated steam were followed up at 8 days and 1, 3, 6 and 12 months (clinical, duplex ultrasound, quality of life [QoL] with SF12). RESULTS: 88 veins were treated in 75 patients. At 6 months, 72/75 (96%) veins were obliterated (95% CI: 89-99) and Kaplan-Meier analysis found an obliteration rate of 96.1% at 12 months. QoL increased at 6 months for both the physical and mental components (p = 0.049 and p < 0.001 respectively). SVS was well tolerated: no major complications were reported. Adverse events occurred mainly at day 8 and incidents amounted to ecchymosis (n = 60) and pain (n = 7). CONCLUSIONS: SVS achieved an obliteration rate similar to that of other thermal ablation techniques. It was well tolerated with minimal post-operative pain.

[A programme to support clinical evaluation of medical devices: pilot experiment in the Rhône-Alpes region]. / Structure de soutien à l'évaluation clinique des dispositifs médicaux : expérience pilote en région Rhône-Alpes.

INTRODUCTION: The drug and medical devices Committee of the University Hospital of Lyon faces the weakness of clinical data available to justify medical devices purchase. The Hospital of Lyon has worked with several organisms of the Rhône-Alpes region to set up a pilot programme aimed at encouraging small and medium enterprises (SMEs) to realise clinical studies for the evaluation of their medical device. We report the results of this experiment which took place from 2007 to 2010. METHODS: Eligible projects were selected on the basis of their scientific interest. A specific structure for regulatory and methodological support was set up. RESULTS: Twenty companies applied, seventeen were selected. Eight research protocols were written; four clinical studies were implemented. These studies were performed by micro-companies for medical devices that could be considered as innovative device or substantial novelty. Two draft protocols were started but deferred by choice of the company. For projects that did not lead to a research protocol or study, the main causes were: a longer than expected development phase (n = 3); a problem linked to methodological feasibility (n = 1); the unsuccessful search for a principal investigator (n = 2); or the company's choice (n = 5). DISCUSSION AND CONCLUSION: This pilot experience in France has supported and trained regional SMEs in clinical research. Its continuation could encourage manufacturers to conduct clinical trials of good quality.

Evidence for induction of the ornithine transcarbamylase expression in Alzheimer's disease.

To more rapidly identify candidate genes located within chromosomal regions of interest defined by genome scan studies in Alzheimer's disease (AD), we have developed a customized microarray containing all the ORFs (n=2741) located within nine of these regions. Levels of gene expression were assessed in total RNA from brain tissue of 12 controls and 12 AD patients. Of all genes showing differential expression, we focused on the ornithine transcarbamylase (OTC) gene on Xp21.1., a key enzyme of the urea cycle which we found to be expressed in AD brains but not in controls, as confirmed by RT-PCR. We also detected mRNA expression of all the other urea cycle enzymes in AD brains. Immunochemistry experiments revealed that the OTC expression was strictly restricted to vascular endothelial cells in brain. Furthermore, OTC activity was 880% increased in the CSF of probable AD cases compared with controls. We analysed the association of the OTC -389 G/A and -241 A/G promoter polymorphisms with the risk of developing AD. We observed that rare haplotypes may be associated with the risk of AD through a possible modulation of the methylation of the OTC promoter. In conclusion, our results suggest the involvement of a new pathway in AD brains involving the urea cycle.

Transcriptomic and genetic studies identify IL-33 as a candidate gene for Alzheimer's disease.

The only recognized genetic determinant of the common forms of Alzheimer's disease (AD) is the epsilon 4 allele of the apolipoprotein E gene (APOE). To identify new candidate genes, we recently performed transcriptomic analysis of 2741 genes in chromosomal regions of interest using brain tissue of AD cases and controls. From 82 differentially expressed genes, 1156 polymorphisms were genotyped in two independent discovery subsamples (n=945). Seventeen genes exhibited at least one polymorphism associated with AD risk, and following correction for multiple testing, we retained the interleukin (IL)-33 gene. We first confirmed that the IL-33 expression was decreased in the brain of AD cases compared with that of controls. Further genetic analysis led us to select three polymorphisms within this gene, which we analyzed in three independent case-control studies. These polymorphisms and a resulting protective haplotype were systematically associated with AD risk in non-APOE epsilon 4 carriers. Using a large prospective study, these associations were also detected when analyzing the prevalent and incident AD cases together or the incident AD cases alone. These polymorphisms were also associated with less cerebral amyloid angiopathy (CAA) in the brain of non-APOE epsilon 4 AD cases. Immunohistochemistry experiments finally indicated that the IL-33 expression was consistently restricted to vascular capillaries in the brain. Moreover, IL-33 overexpression in cellular models led to a specific decrease in secretion of the A beta(40) peptides, the main CAA component. In conclusion, our data suggest that genetic variants in IL-33 gene may be associated with a decrease in AD risk potentially in modulating CAA formation.

Identification of novel TMPRSS2:ERG mechanisms in prostate cancer metastasis: involvement of MMP9 and PLXNA2.

Prostate cancer (PCa) is one of the major public health problems in Western countries. Recently, the TMPRSS2:ERG gene fusion, which results in the aberrant expression of the transcription factor ERG, has been shown to be the most common gene rearrangement in PCa. Previous studies have determined the contributions of this fusion in PCa disease initiation and/or progression in vitro and in vivo. In this study on TMPRSS2:ERG regulation in PCa, we used an androgen receptor and TMPRSS2:ERG fusion double-negative PCa cell model: PC3c. In three cell clones with different TMPRSS2:ERG expression levels, ectopic expression of the fusion resulted in significant induction of cell migration and invasion in a dose-dependent manner. In agreement with this phenotype, high-throughput microarray analysis revealed that a set of genes, functionally associated with cell motility and invasiveness, were deregulated in a dose-dependent manner in TMPRSS2:ERG-expressing cells. Importantly, we identified increased MMP9 (Metalloproteinase 9) and PLXNA2 (Plexin A2) expression in TMPRSS2:ERG-positive PCa samples, and their expression levels were significantly correlated with ERG expression in a PCa cohort. In line with these findings, there was evidence that TMPRSS2:ERG directly and positively regulates MMP9 and PLXNA2 expression in PC3c cells. Moreover, PLXNA2 upregulation contributed to TMPRSS2:ERG-mediated enhancements of PC3c cell migration and invasion. Furthermore, and importantly, PLXNA2 expression was upregulated in metastatic PCa tumors compared with localized primary PCa tumors. This study provides novel insights into the role of the TMPRSS2:ERG fusion in PCa metastasis.

Trends in HRT and anti-osteoporosis medication prescribing in a European population after the WHI study.

UNLABELLED: To assess the prescription patterns of anti-osteoporosis medications, three cross-sectional analyses were performed between 2004 and 2006. Women aged 50 and older were identified from the health insurance claims database of the Rhône-Alpes area. HRT prescriptions decreased while bisphosphonates and raloxifene prescriptions increased, respectively, in different age groups. INTRODUCTION: The objective of this study was to assess the prescription patterns of hormone replacement therapy (HRT) and anti-osteoporosis medications (AOM) in post-menopausal French women since the WHI and the revision of the French clinical practice guidelines in 2004. METHODS: Three cross-sectional analyses were performed between 2004 and 2006. Women aged 50 and older who had at least one claim for a prescription for HRT, bisphosphonates or raloxifene were identified from health insurance claims database of the Rhône-Alpes area. RESULTS: A 39% decrease in the number of women who had HRT was observed (67,241 to 41,024). Twenty-one percent and 18% increases were observed, respectively, for bisphosphonates (39,192 to 47,395) and raloxifene (10,263 to 12,060). HRT and raloxifene were mainly prescribed to women aged 55 to 64 (58% and 39%, respectively), bisphosphonates to women aged 65 to 84 (70%). Ninety-eight percent of women had HRT prescribed by a gynaecologist or a general practitioner (GP). Most AOM were prescribed by a GP; 13% of women had AOM prescribed by a rheumatologist. CONCLUSION: Prescriptions for HRT in post-menopausal French women have significantly decreased while bisphosphonates and raloxifene prescriptions have increased, respectively, in different age groups but to a lesser extent than the HRT decrease.

[Radiotherapy following surgery of the larynx]. / Radiothérapie à la suite de chirurgie laryngée

A method of radiotherapy following total or partial surgery of the larynx is described. Criteria for the selection of patients and a technique of treatment are suggested. The results from 1966 to 1971 are reported.

Thrombosis of the lateral sinus.

Four cases of lateral sinus thrombosis have been treated at Notre-Dame Hospital, Montreal, since 1960. A review of the literature of this pathology is reported, and two cases treated in the past three months are presented.

Reconstruction of the floor of the mouth following surgery for cancer.

The authors, members of a very active service of Head and Neck Surgery, tell of their experience with the reconstruction of the floor of the mouth following surgery for cancer. They feel that the simplest methods of reconstruction are the best.

Differential modulation of Bordetella pertussis virulence genes as evidenced by DNA microarray analysis.

The production of most factors involved in Bordetella pertussis virulence is controlled by a two-component regulatory system termed BvgA/S. In the Bvg+ phase virulence-activated genes (vags) are expressed, and virulence-repressed genes (vrgs) are down-regulated. The expression of these genes can also be modulated by MgSO(4) or nicotinic acid. In this study we used microarrays to analyse the influence of BvgA/S or modulation on the expression of nearly 200 selected genes. With the exception of one vrg, all previously known vags and vrgs were correctly assigned as such, and the microarray analyses identified several new vags and vrgs, including genes coding for putative autotransporters, two-component systems, extracellular sigma factors, the adenylate cyclase accessory genes cyaBDE, and two genes coding for components of a type III secretion system. For most of the new vrgs and vags the results of the microarray analyses were confirmed by RT-PCR analysis and/or lacZfusions. The degree of regulation and modulation varied between genes, and showed a continuum from strongly BvgA/S-activated genes to strongly BvgA/S-repressed genes. The microarray analyses also led to the identification of a subset of vags and vrgs that are differentially regulated and modulated by MgSO(4) or nicotinic acid, indicating that these genes may be targets for multiple regulatory circuits. For example, the expression of bilA, a gene predicted to encode an intimin-like protein, was found to be activated by BvgA/S and up-modulated by nicotinic acid. Furthermore, surprisingly, in the strain analysed here, which produces only type 2 fimbriae, the fim3 gene was identified as a vrg, while fim2 was confirmed to be a vag.