Impact of pre-analytical factors on mycobacterium cultures contaminations rates in Burkina Faso, West Africa

Introduction: for a high quality level diagnosis, mycobacterium culture must comply with the pre-analytical and analytical conditions recommended by the WHO and the country National Tuberculosis Program (NTP). In this study, we determined whether temperature and duration of sputum storage were associated with culture contamination in Burkina Faso. Methods: sputa were collected in 5 districts labs in Burkina Faso. Temperature and duration of sputum storage were recorded. After the collection, sputa were decontaminated using Petroff modified method, and the pellet was inoculated on LJ media and LJ media supply with 2% sodium pyruvate. Risk of culture contamination associated with temperature and duration of sputum storage was measured by Chi2 test and logistic regression. Results: out of 404 specimens, 61% (246/404) were stored between 2 and 8°C, and 15% (61/404) were processed within three days. The global contamination rate was 24%, with only 8% for samples respecting WHO recommendations, up to 35% for others. Storage at room temperature was associated with a significantly higher risk of contamination compared to storage at 2-8°C (OR 2.24, p=0.001, IC 95%). Conclusion: the recommendations about the temperature and the duration of sputum storage before cultures are not completely respected. This leads to high contamination rate of mycobacterium culture. It will be necessary to take logistics measures in peripherals health services or to develop more selective medium for mycobacterium culture in low income countries

Impact of COVID-19 infection on lung function and nutritional status amongst individuals with cystic fibrosis:A global cohort study

Background: Factors associated with severe COVID-19 infection have been identified; however, the impact of infection on longer-term outcomes is unclear. The objective of this study was to examine the impact of COVID-19 infection on the trajectory of lung function and nutritional status in people with cystic fibrosis (pwCF). Methods: This is a retrospective global cohort study of pwCF who had confirmed COVID-19 infection diagnosed between January 1, 2020 and December 31, 2021. Forced expiratory volume in one second percent predicted (ppFEV1) and body mass index (BMI) twelve months prior to and following a diagnosis of COVID-19 were recorded. Change in mean ppFEV1 and BMI were compared using a t-test. A linear mixed-effects model was used to estimate change over time and to compare the rate of change before and after infection. Results: A total of 6,500 cases of COVID-19 in pwCF from 33 countries were included for analysis. The mean difference in ppFEV1 pre- and post-infection was 1.4 %, (95 % CI 1.1, 1.7). In those not on modulators, the difference in rate of change pre- and post-infection was 1.34 %, (95 % CI -0.88, 3.56) per year (p = 0.24) and -0.74 % (-1.89, 0.41) per year (p = 0.21) for those on elexacaftor/tezacaftor/ivacaftor. No clinically significant change was noted in BMI or BMI percentile before and after COVID-19 infection. Conclusions: No clinically meaningful impact on lung function and BMI trajectory in the year following infection with COVID-19 was identified. This work highlights the ability of the global CF community to unify and address critical issues facing pwCF.</p

Performance of FACSPresto Point-of-Care Instrument for CD4-T Cell Enumeration in Human Immunodeficiency Virus (HIV)-Infected Patients Attending Care and Treatment Clinics in Belgium and Tanzania.

CD4 T-cell counts are widely used to assess treatment eligibility and to follow-up HIV-infected patients. The World Health Organization prequalification of in vitro diagnostics program conducted a performance evaluation of the FACSPresto (BD Biosciences), a new point-of-care instrument to measure absolute CD4-T cell (CD4) counts and percentages in venous and capillary blood samples from HIV-infected patients.Patients were recruited in Belgium (200 patients) and in Tanzania (247 patients). Venous blood samples were analyzed in two nearby reference laboratories. In addition, nurses/technicians collected a capillary blood sample by finger prick directly into a FACSPresto CD4 cartridge. Assay precision was assessed on fresh blood and on external quality control samples. Trueness (bias) was assessed by comparing results from FACSPresto with the reference (single-platform FACSCalibur). Clinical misclassification was measured at 200, 350 and 500 cells/μL thresholds.Intra-assay precision was < 6%, and inter-assay < 8%. CD4 results from FACSPresto and reference method resulted in regression slopes of 0.99-1.11 using either venous or capillary blood. Correlation was better for venous than for capillary blood (minimum 0.97 vs 0.93 respectively). Capillary blood resulted in a larger bias than venous blood, with 24 and 83 cells/μL for absolute CD4 counts on capillary blood in Antwerp and Dar es Salaam respectively, vs 12 and 41 cells/μL on venous blood. Bias on CD4% was < 1% on both venous and capillary blood, and was proportionally better than for absolute CD4 counts. Clinical misclassification was in line with the average overestimation, showing a very good specificity, but sensitivity around 70-90%. The rejection rate was 11% on first reading, leading to 6% of all samples without final result after a second reading.The FACSPresto performed very well on venous blood samples, and well on capillary blood samples

Identification de la cyclooxygénase-2 comme un acteur majeur de l'adaptation du transcriptome d'effet endothéliales et les cellules tumorales à l'hypoxie cyclique: sur l'angiogénèse et les métastases.

Purpose: Cyclic hypoxia in tumors originates from heterogeneities in RBC flux and influences not only tumor cells but also endothelial cells lining tumor blood vessels. Whether pO2 fluctuations, particularly transient reoxygenation periods, alter the well-known hypoxia-inducible factor (HIF)–dependent gene program is largely unknown. Experimental Design: We compared the transcriptomic profiles of endothelial and tumor cells exposed to cyclic hypoxia versus continuous hypoxia to uncover a possible differential effect on angiogenesis and metastases. Results: Microarray analyses identified early genes that were selectively induced by cyclic hypoxia in endothelial cells. Among them, we focused on PTGS2 because the observed increase in mRNA expression led to a significant increase in the expression and activity of cyclooxygenase-2 (COX-2; the protein product of PTGS2). HIF-1α was shown to be stabilized by cyclic hypoxia (despite reoxygenation periods) and to favor COX-2 induction as validated by the use of echinomycin and HIF-1α targeting small interfering RNA. Using a specific COX-2 inhibitor and a dedicated COX-2 targeting small interfering RNA, we documented that COX-2 accounted for the higher endothelial cell survival and angiogenic potential conferred by cyclic hypoxia. Cyclic hypoxia also led to a preferential COX-2 induction in tumor cells and, contrary to continuous hypoxia, fostered a higher metastatic take of prechallenged tumor cells. Conclusions: Our study documents that PTGS2/COX-2 is part of a cyclic hypoxia gene signature and largely accounts for the unique phenotype of endothelial and tumor cells exposed to fluctuations in pO2, thereby offering new perspectives for the clustering of tumors expressing COX-2 together with other cyclic hypoxia-responsive genes. Clin Cancer Res; 16(2); 410–9OBJECTIF: hypoxie cycliques dans les tumeurs proviennent de l'hétérogénéité dans le flux de RBC et influence non seulement les cellules tumorales mais également des cellules endothéliales qui tapissent les vaisseaux sanguins tumoraux. Whether pO(2) fluctuations, particularly transient reoxygenation periods, alter the well-known hypoxia-inducible factor (HIF)-dependent gene program is largely unknown. Que Po (2) les fluctuations, en particulier réoxygénation des périodes transitoires, de modifier l'hypoxie bien connue-inducible factor (HIF)-programme des gènes dépendant est largement inconnue. EXPERIMENTAL DESIGN: We compared the transcriptomic profiles of endothelial and tumor cells exposed to cyclic hypoxia versus continuous hypoxia to uncover a possible differential effect on angiogenesis and metastases. EXPERIMENTAL DESIGN: Nous avons comparé les profils transcriptomiques de endothéliales et les cellules tumorales exposées à l'hypoxie cyclique par rapport à l'hypoxie continue de découvrir un effet différentiel possible sur l'angiogénèse et les métastases. RESULTS: Microarray analyses identified early genes that were selectively induced by cyclic hypoxia in endothelial cells. RÉSULTATS: Les analyses de biopuces identifié les gènes précoces qui ont été sélective induite par l'hypoxie cyclique dans les cellules endothéliales. Among them, we focused on PTGS2 because the observed increase in mRNA expression led to a significant increase in the expression and activity of cyclooxygenase-2 (COX-2; the protein product of PTGS2). Parmi eux, nous nous sommes concentrés sur PTGS2 parce que l'augmentation observée dans l'expression des ARNm conduit à une augmentation significative de l'expression et l'activité de la cyclooxygénase-2 (COX-2, la protéine produite par PTGS2). HIF-1alpha was shown to be stabilized by cyclic hypoxia (despite reoxygenation periods) and to favor COX-2 induction as validated by the use of echinomycin and HIF-1alpha targeting small interfering RNA. HIF-1alpha a été montré pour être stabilisé par l'hypoxie cyclique (en dépit de réoxygénation périodes) et à favoriser la COX-2 induction tels que validés par l'utilisation de echinomycin et HIF-1alpha destiné aux petits ARN interférents. Using a specific COX-2 inhibitor and a dedicated COX-2 targeting small interfering RNA, we documented that COX-2 accounted for the higher endothelial cell survival and angiogenic potential conferred by cyclic hypoxia. L'utilisation d'un spécifiques de la COX-2 et un inhibiteur de la COX-2 dédié destiné aux petits ARN interférents, nous avons documenté que la COX-2 ont représenté pour la survie plus élevé de cellules endothéliales et le potentiel angiogénique conférés par l'hypoxie cyclique. Cyclic hypoxia also led to a preferential COX-2 induction in tumor cells and, contrary to continuous hypoxia, fostered a higher metastatic take of prechallenged tumor cells. Cyclic hypoxie a également conduit à la COX-2 induction préférentielle dans les cellules tumorales et, contrairement à l'hypoxie en continu, a favorisé une plus prendre métastatique des cellules tumorales prechallenged. CONCLUSIONS: Our study documents that PTGS2/COX-2 is part of a cyclic hypoxia gene signature and largely accounts for the unique phenotype of endothelial and tumor cells exposed to fluctuations in pO(2), thereby offering new perspectives for the clustering of tumors expressing COX-2 together with other cyclic hypoxia-responsive genes. CONCLUSIONS: Notre étude montre que PTGS2/COX-2 fait partie d'une signature cyclique hypoxie génique et explique en grande partie le phénotype unique de endothéliales et les cellules tumorales exposées à des fluctuations de Po (2), offrant ainsi de nouvelles perspectives pour le regroupement des tumeurs exprimant COX-2, ainsi que l'hypoxie cyclique autres gènes sensibles

Heat shock protein 90 transfection reduces ischemia-reperfusion-induced myocardial dysfunction via reciprocal endothelial NO synthase serine 1177 phosphorylation and threonine 495 dephosphorylation

Objectives-The interaction of the heat shock protein 90 (Hsp90) with the endothelial NO synthase ( eNOS) has been shown to account for a sustained production of NO in vitro. Here, we examined whether overexpression of Hsp90 in a pig model of cardiac infarct could preserve the myocardium from the deleterious effects of ischemia-reperfusion. Methods and Results-Percutaneous liposome-based gene transfer was performed by retroinfusion of the anterior interventricular vein before left anterior descending occlusion and reperfusion. We found that recombinant Hsp90 expression in the ischemic region of the heart led to a 33% reduction in infarct size and prevented the increase in postischemic left ventricular end diastolic pressure observed in mock-transfected animals. Regional myocardial function, assessed by subendocardial segment shortening in the infarct region, was increased in Hsp90-transfected animals at baseline and after pacing. All these effects were completely abrogated by administration of the NOS inhibitor N-G-nitro-L-arginine methyl ester. We further documented in vivo and in cultured endothelial cells that the cardioprotective effects of Hsp90 were associated to its capacity to act as an adaptor for both the kinase Akt and the phosphatase calcineurin, thereby promoting eNOS serine 1177 phosphorylation and threonine 495 dephosphorylation, respectively. Conclusions-Hsp90 is a promising target to enhance NO formation in vivo, which may efficiently reduce myocardial reperfusion injury

Clinical misclassification of FACSPresto for venous and capillary blood versus FACSCalibur, at strict thresholds ≤ 200, 350 and 500 cells/μL.

<p>Clinical misclassification of FACSPresto for venous and capillary blood versus FACSCalibur, at strict thresholds ≤ 200, 350 and 500 cells/μL.</p

FACSPresto performance with venous and capillary blood on FACSPresto, compared to each other’s.

<p>FACSPresto performance with venous and capillary blood on FACSPresto, compared to each other’s.</p

FACSPresto performance with venous blood on FACSPresto compared to FACSCalibur (reference).

<p>FACSPresto performance with venous blood on FACSPresto compared to FACSCalibur (reference).</p

Coefficient of variation (%CV) for the different precisions assays.

<p>Coefficient of variation (%CV) for the different precisions assays.</p