Cardiac autonomic control in the obstructive sleep apnea

Introduction: The sympathetic activation is considered to be the main mechanism involved in the development of cardiovascular diseases in obstructive sleep apnea (OSA). The heart rate variability (HRV) analysis represents a non-invasive tool allowing the study of the autonomic nervous system. The impairment of HRV parameters in OSA has been documented. However, only a few studies tackled the dynamics of the autonomic nervous system during sleep in patients having OSA.Aims: To analyze the HRVover sleep stages and across sleep periods in order to clarify the impact of OSA on cardiac autonomic modulation. The second objective is to examine the nocturnal HRV of OSA patients to find out which HRV parameter is the best to reflect the symptoms severity.Methods: The study was retrospective. We have included 30 patients undergoing overnight polysomnography. Subjects were categorized into two groups according to apneahypopnea index (AHI): mild-to-moderate OSAS group (AHI: 5-30) and severe OSAS group (AHI>30). The HRV measures for participants with low apneahypopnea indices were compared to those of patients with high rates of apneahypopnea across the sleep period and sleep stages.Results: HRV measures during sleep stages for the group with low rates of apneahypopnea have indicated a parasympathetic activation during non-rapid eye movement (NREM) sleep. However, no significant difference has been observed in the high AHI group except for the mean of RR intervals (mean RR). The parasympathetic activity tended to increase across the night but without a statistical difference. After control of age and body mass index, the most significant correlation found was for the mean RR (p =0.0001, r = -0.248).Conclusion: OSA affects sympathovagal modulation during sleep, and this impact has been correlated to the severity of the disease. The mean RR seemed to be a better index allowing the sympathovagal balance appreciation during the night in OSA.Keywords: autonomic nervous system; sleep apnea; heart rate; sleep; circadia

Malaria Risk Factors in Dielmo, A Senegalese Malaria-Endemic Village, Between October and November of 2013: A Case-Control Study

International audienceThe incidence of malaria has decreased recently in parts of Africa, coinciding with the widespread use of long-lasting insecticide-treated nets (LLINs) and artemisinin-based combination therapy (ACT). This reduction was also observed in Dielmo, our study area, and it was associated with the use of ACT as the first-line treatment against malaria beginning in 2006 and the implementation of LLINs in 2008. However, an unexplained slight increase in malaria incidence was observed in October and November of 2013. The aim of this study was to identify individual and environmental risk factors for malaria using a case-control study approach. Thirty cases and sixty controls were investigated. The use of LLINs was protective against malaria (adjusted odds ratio [AOR] = 0.10; 95% confidence interval [95% CI] = 0.02–0.45; P = 0.003). The risk of malaria transmission was high among villagers who watched television outside the house or the bedroom during the night (AOR = 8.83; 95% CI = 1.39–56.22; P = 0.021). The use of LLINs should be reinforced by the use of individual protection measures to avoid malaria transmission outside of the home. BACKGROUN

Central factorials under the Kontorovich-Lebedev transform of polynomials

We show that slight modifications of the Kontorovich-Lebedev transform lead to an automorphism of the vector space of polynomials. This circumstance along with the Mellin transformation property of the modified Bessel functions perform the passage of monomials to central factorial polynomials. A special attention is driven to the polynomial sequences whose KL-transform is the canonical sequence, which will be fully characterized. Finally, new identities between the central factorials and the Euler polynomials are found.Comment: also available at http://cmup.fc.up.pt/cmup/ since the 2nd August 201

Healthcare-associated infections in a tunisian university hospital: From analysis to action

Introduction: our study was conducted, in university hospital center (UHC) Farhat Hached of Sousse (city in Tunisian center-east), within healthcare-associated infections (HAI) epidemiological surveillance (ES) program,  based, among others, on HAI regular prevalence surveys. Our objectives are to resituate HAI prevalence rate and to identify their risk factors (RF) in order to adjust, in our hospital, prevention programs.Methods: it is a transversal descriptive study, including all patients who had been hospitalized for at least 48 hours, measuring prevalence of HAI a “given day”, with only one passage by service. Risk factors were  determined using Epiinfo 6.0, by uni-varied analysis, then, logistic  regression stepwise descending for the variables whose pResults: the study focused on 312 patients. Infected patients prevalence was 12.5% and that of HAI was 14.5 %. Infections on peripheral venous catheter (PVC)  dominated (42.2%) among all HAI identified. HAI significant RF were neutropenia (p<10-4) for intrinsic factors, and PVC for extrinsic factors (p=0,003). Conclusion: predominance of infections on PVC should be subject of specific prevention actions, including retro-information strategy, prospective ES, professional practices evaluation and finally training and increasing awareness of health personnel with hygiene measures. Finally,  development of a patient safety culture with personnel ensures best adherence to hygiene measures and HAI prevention

STABILITE ELASTOPLASTIQUE DES BARRES COMPRIME-FLECHIES A IMPERFECTIONS INITIALES

La sédimentation des barrages dans les pays de l’Afrique du nord est très élevée et même spectaculaire. Elle est due directement aux forts taux d’érosion des bassins versants, dont les particules solides sont drainées directement par les cours d’eau et provoqueront à l’entrée des retenues des courants de densité. Cette sédimentation pose d’énormes problèmes à savoir ; la réduction de la capacité, l’obturation des organes de vidange, la sécurité de l’ouvrage, la sédimentation des canaux d’irrigation et elle a même un impact sur la qualité de l’eau

On d-symmetric classical d-orthogonal polynomials

AbstractThe d-symmetric classical d-orthogonal polynomials are an extension of the standard symmetric classical polynomials according to the Hahn property. In this work, we give some characteristic properties for these polynomials related to generating functions and recurrence-differential equations. As applications, we characterize the d-symmetric classical d-orthogonal polynomials of Boas-Buck type, we construct a (d+1)-order linear differential equation with polynomial coefficients satisfied by each polynomial of a d-symmetric classical d-orthogonal set and we show that the d-symmetric classical d-orthogonal property is preserved by the derivative operator. Some of the obtained properties appear to be new, even for the case d=1

The P2Y2 nucleotide receptor is an inhibitor of vascular calcification

BACKGROUND AND AIMS: Mutations in the 5'-nucleotidase ecto (NT5E) gene that encodes CD73, a nucleotidase that converts AMP to adenosine, are linked to arterial calcification. However, the role of purinergic receptor signaling in the pathology of intimal calcification is not well understood. In this study, we examined whether extracellular nucleotides acting via P2Y2 receptor (P2Y2R) modulate arterial intimal calcification, a condition highly correlated with cardiovascular morbidity. METHODS: Apolipoprotein E, P2Y2R double knockout mice (ApoE-/-P2Y2R-/-) were used to determine the effect of P2Y2R deficiency on vascular calcification in vivo. Vascular smooth muscle cells (VSMC) isolated from P2Y2R-/- mice grown in high phosphate medium were used to assess the role of P2Y2R in the conversion of VSMC into osteoblasts. Luciferase-reporter assays were used to assess the effect of P2Y2R on the transcriptional activity of Runx2. RESULTS: P2Y2R deficiency in ApoE-/- mice caused extensive intimal calcification despite a significant reduction in atherosclerosis and macrophage plaque content. The ectoenzyme apyrase that degrades nucleoside di- and triphosphates accelerated high phosphate-induced calcium deposition in cultured VSMC. Expression of P2Y2R inhibits calcification in vitro inhibited the osteoblastic trans-differentiation of VSMC. Mechanistically, expression of P2Y2R inhibited Runx2 transcriptional activation of an osteocalcin promoter driven luciferase reporter gene. CONCLUSIONS: This study reveals a role for vascular P2Y2R as an inhibitor of arterial intimal calcification and provides a new mechanistic insight into the regulation of the osteoblastic trans-differentiation of SMC through P2Y2R-mediated Runx2 antagonism. Given that calcification of atherosclerotic lesions is a significant clinical problem, activating P2Y2R may be an effective therapeutic approach for treatment or prevention of vascular calcification

Implementation of the INTERGROWTH-21st Project in Kenya

The African site in the INTERGROWTH-21(st) Project was Parklands, a wealthy suburb of Nairobi, Kenya, with a largely middle-to-high socio-economic status population. There are three hospitals with obstetric units in Parklands, with approximately 4300 births per year. The Newborn Cross-Sectional Study (NCSS) sample was drawn from all three hospitals, covering 100% of births in this target population. The Fetal Growth Longitudinal Study (FGLS) sample was recruited from antenatal clinics serving these hospitals, using the eligibility criteria in the INTERGROWTH-21(st) protocol. Special activities to raise awareness of the study included securing media coverage and distributing leaflets in antenatal clinic waiting rooms. FGLS required women to be recruited in the first trimester; therefore, a major challenge at this study site was the high background frequency of first antenatal consultations in the second trimester. The problem was overcome by the study awareness campaign, as a result of which more women started attending antenatal care earlier in pregnancy

Acute febrile illness and influenza disease burden in a rural cohort dedicated to malaria in Senegal, 2012-2013

Background African populations are considered to be particularly vulnerable to fever illnesses, including malaria, and acute respiratory disease, owing to limited resources and overcrowding. However, the overall burden of influenza in this context is poorly defined and incidence data for African countries are scarce. We therefore studied the fever syndrome incidence and more specifically influenza incidence in a cohort of inhabitants of Dielmo and Ndiop in Sokone district, Senegal. Methods Daily febrile-illness data were prospectively obtained from January 2012 to December 2013 from the cohort of the villages of Dielmo and Ndiop, initially dedicated to the study of malaria. Nasopharyngeal swabs were collected from, and malaria diagnosis tests (thick blood smears) carried out on, every febrile individual during clinical visits; reverse transcriptase- polymerase chain reaction was used to identify influenza viruses in the samples. Binomial negative regression analysis was used to study the relationship between the monthly incidence rate and various covariates. Results In Dielmo and Ndiop, the incidence ofmalaria has decreased, but fever syndromes remain frequent. Among the 1036 inhabitants included in the cohort, a total of 1,129 episodes of fever were reported. Influenza was present all year round with peaks in October-December 2012 and August 2013. The fever, ILI and influenza incidence density rates differed significantly between age groups. At both sites, the adjusted incidence relative risks for fever syndromes and ILI were significantly higher in the [6-24 months) than other age groups: 7.3 (95% CI: [5.7-9.3]) and 16.1 (95% CI: [11.1-23.3]) respectively. The adjusted incidence relative risk for influenza was significantly higher for the [0-6 months) than other age groups: 9.9 (95% CI: [2.9-33.6]). At both sites, incidence density rates were lowest among adults > = 50 years. Conclusions In this rural setting in Senegal, influenza was most frequent among the youngest children. Preventive strategies targeting this population should be implemented