Poor value of pulsed-field gel electrophoresis to investigate long-term scale epidemiology of methicillin-resistant Staphylococcus aureus.

Pulsed-field gel electrophoresis (PFGE) is widely used for epidemic investigations of methicillin-resistant Staphylococcus aureus (MRSA). In the present study, we evaluated its use in a long-term epidemiological setting (years to few decades, country to continent level). The clustering obtained from PFGE patterns after SmaI digestion of the DNA of 20 strains was compared to that obtained using a phylogenetic typing method (multiprimer RAPD). The results showed that the analysis of small PFGE bands (10-85kb) correlates better with multiprimer RAPD than the analysis of large PFGE bands (>85-700kb), suggesting that the analysis of small bands would be more suitable for the investigation of long-term epidemiological setting. However, given the technical difficulties to obtain a good resolution of these bands and the putative presence of plasmids among them, PFGE does not appear to be a method of choice for the long-term epidemiology analysis of MRSA.

Daily physical activity assessment: what is the importance of upper limb movements vs whole body movements?

OBJECTIVE: The movement of the upper limbs (eg fidgeting-like activities) is a meaningful component of nonexercise activity thermogenesis (NEAT). This study examined the relationship between upper limb movements and whole body trunk movements, by simultaneously measuring energy expenditure during the course of the day. DESIGN: A cross-sectional study consisting of 88 subjects with a wide range in body mass index (17.3-32.5 kg/m(2)). The energy expenditure over a 24-h period was measured in a large respiratory chamber. The body movements were assessed by two uniaxial-accelerometers during daytime, one on the waist and the other on the dominant arm. The accelerometry scores from level 0 (=immobile) up to level 9 (=maximal intensity) were recorded. The activities of subjects were classified into eight categories: walking at two speeds on a horizontal treadmill (A & B), ambling (C), self-care tasks (D), desk work (E), meals (F), reading (G), watching TV (H). RESULTS: There was a significant relationship between the accelerometry scores from the waist (ACwaist) and that from the wrist (ACwrist) over the daytime period (R(2)=0.64; P<0.001). The ACwrist was systematically higher than the ACwaist during sedentary activities, whereas it was the reverse for walking activities. ACwrist to ACwaist ratio of activities E-H were above 1.0 and for walking activities (A-C) were below 1.0. A multiple regression analysis for predicting daytime energy expenditure revealed that the explained variance improved by 2% only when the ACwrist was added as a second predictor in addition to the ACwaist. This indicates that the effect of the ACwrist for predicting energy expenditure was of limited importance in our conditions of measurement. CONCLUSIONS: The acceleration of the upper limbs which includes fidgeting is more elevated than that of the whole body for sitting/lying down activities. However, their contribution to energy expenditure is lower than whole body trunk movements, thus indicating that the weight-bearing locomotion activities may be a key component of NEAT. However, its contribution may depend on the total duration of the upper limb movements during the course of the day.

Sylvatic population of Triatoma infestans from the Bolivian Chaco: from field collection to characterization

A sylvatic Triatoma infestans DM (dark morph) population detected in the Bolivian Chaco was characterized and compared with various domestic ones. The degree of differentiation of DM was clearly within the T. infestans intra-specific level. Nevertheless marked chromatic and morphometric differences as well as differences in antennal pattern, chromosome banding and randomly amplified polymorphic DNA support the hypothesis of a distinct population. Continuous exchange of insects between wild and domestic habitats seems unlikely in the Chaco.

Blood glucose level on postoperative day 1 is predictive of adverse outcomes after cardiovascular surgery

AIM: Hyperglycaemia is now a recognized predictive factor of morbidity and mortality after coronary artery bypass grafting (CABG). For this reason, we aimed to evaluate the postoperative management of glucose control in patients undergoing cardiovascular surgery, and to assess the impact of glucose levels on in-hospital mortality and morbidity. METHODS: This was a retrospective study investigating the association between postoperative blood glucose and outcomes, including death, post-surgical complications, and length of stay in the intensive care unit (ICU) and in hospital. RESULTS: A total of 642 consecutive patients were enrolled into the study after cardiovascular surgery (CABG, carotid endarterectomy and bypass in the lower limbs). Patients' mean age was 68+/-10 years, and 74% were male. In-hospital mortality was 5% in diabetic patients vs 2% in non-diabetic patients (OR: 1.66, P=0.076). Having blood glucose levels in the upper quartile range (> or =8.8 mmol/L) on postoperative day 1 was independently associated with death (OR: 10.16, P=0.0002), infectious complications (OR: 1.76, P=0.04) and prolonged ICU stay (OR: 3.10, P<0.0001). Patients presenting with three or more hypoglycaemic episodes (<4.1 mmol/L) had increased rates of mortality (OR: 9.08, P<0.0001) and complications (OR: 8.57, P<0.0001). CONCLUSION: Glucose levels greater than 8.8 mmol/L on postoperative day 1 and having three or more hypoglycaemic episodes in the postoperative period were predictive of mortality and morbidity among patients undergoing cardiovascular surgery. This suggests that a multidisciplinary approach may be able to achieve better postoperative blood glucose control. Conclusion: Objectif: L'hyperglycémie a été reconnue comme facteur prédictif de morbidité et mortalité après un pontage aortocoronaire. Notre étude avait pour objectif d'évaluer la prise en charge postopératoire des glycémies chez les patients qui avaient subi une intervention chirurgicale cardiovasculaire et d'évaluer l'impact de ces glycémies sur la mortalité et la morbidité intrahospitalières. Méthodes: Étude rétrospective recherchant une association entre la glycémie postopératoire et les complications postchirurgicales, la mortalité et la durée du séjour aux soins intensifs et à l'hôpital. Résultats: L'étude a été réalisée sur 642 patients qui avaient subi une intervention chirurgicale cardiovasculaire (ex. pontage aortocoronaire, endartérectomie de la carotide, pontage artériel des membres inférieurs). L'âge moyen est de 68 ± 10 ans et 74 % des patients étaient de sexe masculin. La mortalité intrahospitalière a été de 5 % parmi les patients diabétiques et 2 % chez les non-diabétiques (OR 1,66, p = 0,076). Les taux de glycémies situés dans le quartile supérieur (≥ 8,8 mmol/l) à j1 postopératoire sont associés de manière indépendante avec la mortalité (OR 10,16, 95 % CI 3,20-39,00, p = 0,0002), les complications infectieuses (OR 1,76, 95 % CI 1,02-3,00, p = 0,04) et la durée du séjour aux soins intensifs (OR 3,10, 95 % CI 1,83-5,38, p < 0,0001). Les patients qui avaient présenté trois hypoglycémies ou plus (< 4,1 mmol/l) ont présenté un taux augmenté de mortalité (OR 9,08, p ≤ 0,0001) et de complications (OR 8,57, p < 0,0001). Conclusion : Des glycémies supérieures à 8,8 mmol/l à j1 postopératoire et la présence de trois hypoglycémies ou plus en période postopératoire sont des facteurs prédictifs de mauvais pronostic chez les patients qui avaient subi une intervention chirurgicale cardiovasculaire. Ainsi, une approche multidisciplinaire devrait être proposée afin d'obtenir un meilleur contrôle postopératoire des glycémies.

Tectonic evolution of the High Himalaya in upper Lahul (NW Himalaya, India)

The Upper Lahul region in the NW Himalaya is located in the transition zone between the High Himalayan Crystalline (HHC) to the SW and the Tethyan Zone sedimentary series to the NE. The tectonic evolution of these domains during the Himalayan Orogeny is the consequence of a succession of five deformation events. An early D1 phase corresponds to synmetamorphic, NE verging folding. This deformation created the Tandi Syncline, which consists of Permian to Jurassic Tethyan metasediments cropping out in the core of a large-scale synformal fold within the HHC paragneiss. This tectonic event is interpreted as related to a NE directed nappe stacking (Shikar Beh Nappe), probably during the late Eocene to the early Oligocene. A subsequent D2a phase caused SW verging folding in the HHC. This deformation is interpreted as contemporaneous with late Oligocene to early Miocene SW directed thrusting along the Main Central Thrust. In the Tethyan Zone, a D2b phase is marked by a decollement thrust, a system of reverse faults, and gentle folds, associated with SW directed tectonic movements. This deformation is related to an imbricate structure, characteristic of a shallow structural level, and developed in the frontal part of a nappe affecting the Tethyan Zone units of SE Zanskar (Nyimaling-Tsarap Nappe). A later D3 phase generated the Chandra Dextral Shear Zone (CDSZ), a large-scale, ductile, dextral strike-slip shear zone, located in the transition zone between the HHC and the Tethyan Himalaya. The CDSZ most likely represents a part of a system of early Miocene extensional and/or dextral, strike-slip shear zones-observed at the HHC-Tethyan Zone contact along the entire Himalaya. A final D4 phase induced large-scale doming and NE:verging back folding.

Blood glucose level on postoperative day 1 is predictive of adverse outcomes after cardiovascular surgery.

AIM: Hyperglycaemia is now a recognized predictive factor of morbidity and mortality after coronary artery bypass grafting (CABG). For this reason, we aimed to evaluate the postoperative management of glucose control in patients undergoing cardiovascular surgery, and to assess the impact of glucose levels on in-hospital mortality and morbidity. METHODS: This was a retrospective study investigating the association between postoperative blood glucose and outcomes, including death, post-surgical complications, and length of stay in the intensive care unit (ICU) and in hospital. RESULTS: A total of 642 consecutive patients were enrolled into the study after cardiovascular surgery (CABG, carotid endarterectomy and bypass in the lower limbs). Patients' mean age was 68+/-10 years, and 74% were male. In-hospital mortality was 5% in diabetic patients vs 2% in non-diabetic patients (OR: 1.66, P=0.076). Having blood glucose levels in the upper quartile range (> or =8.8 mmol/L) on postoperative day 1 was independently associated with death (OR: 10.16, P=0.0002), infectious complications (OR: 1.76, P=0.04) and prolonged ICU stay (OR: 3.10, P<0.0001). Patients presenting with three or more hypoglycaemic episodes (<4.1 mmol/L) had increased rates of mortality (OR: 9.08, P<0.0001) and complications (OR: 8.57, P<0.0001). CONCLUSION: Glucose levels greater than 8.8 mmol/L on postoperative day 1 and having three or more hypoglycaemic episodes in the postoperative period were predictive of mortality and morbidity among patients undergoing cardiovascular surgery. This suggests that a multidisciplinary approach may be able to achieve better postoperative blood glucose control.

Nava enhances ventilatory variability and diaphragmatic activity/tidal volume coupling

INTRODUCTION. Neurally Adjusted Ventilatory Assist (NAVA) is a new ventilatory mode in which ventilator settings are adjusted based on the electrical activity detected in the diaphragm (Eadi). This mode offers significant advantages in mechanical ventilation over standard pressure support (PS) modes, since ventilator input is determined directly from patient ventilatory demand. Therefore, it is expected that tidal volume (Vt) under NAVA would show better correlation with Eadi compared with PS, and exhibit greater variability due to the variability in the Eadi input to the ventilator. OBJECTIVES. To compare tidal volume variability in PS and NAVA ventilation modes, and its correlation with patient ventilatory demand (as characterized by maximum Eadi). METHODS. Acomparative study of patient-ventilator interaction was performed for 22 patients during standard PS with clinician determined ventilator settings; and NAVA, with NAVA gain set to ensure the same peak airway pressure as the total pressure obtained in PS. A 20 min continuous recording was performed in each ventilator mode. Respiratory rate, Vt, and Eadi were recorded. Tidal volume variance and Pearson correlation coefficient between Vt and Eadi were calculated for each patient. A periodogram was plotted for each ventilator mode and each patient, showing spectral power as a function of frequency to assess variability. RESULTS. Median, lower quartile and upper quartile values for Vt variance and Vt/Eadi correlation are shown in Table 1. The NAVA cohort exhibits substantially greater correlation and variance than the PS cohort. Power spectrums for Vt and Eadi are shown in Fig. 1 (PS and NAVA) for a typical patient. The enlarged section highlights how changes in Eadi are highly synchronized with NAVA ventilation, but less so for PS. CONCLUSIONS. There is greater variability in tidal volume and correlation between tidal volume and diaphragmatic electrical activity with NAVA compared to PS. These results are consistent with the improved patient-ventilator synchrony reported in the literature.

A Genome-Wide Association Study of Upper Aerodigestive Tract Cancers Conducted within the INHANCE Consortium

Genome-wide association studies (GWAS) have been successful in identifying common genetic variation involved in susceptibility to etiologically complex disease. We conducted a GWAS to identify common genetic variation involved in susceptibility to upper aero-digestive tract (UADT) cancers. Genome-wide genotyping was carried out using the Illumina HumanHap300 beadchips in 2,091 UADT cancer cases and 3,513 controls from two large European multi-centre UADT cancer studies, as well as 4,821 generic controls. The 19 top-ranked variants were investigated further in an additional 6,514 UADT cancer cases and 7,892 controls of European descent from an additional 13 UADT cancer studies participating in the INHANCE consortium. Five common variants presented evidence for significant association in the combined analysis (p≤5×10−7). Two novel variants were identified, a 4q21 variant (rs1494961, p = 1×10−8) located near DNA repair related genes HEL308 and FAM175A (or Abraxas) and a 12q24 variant (rs4767364, p = 2×10−8) located in an extended linkage disequilibrium region that contains multiple genes including the aldehyde dehydrogenase 2 (ALDH2) gene. Three remaining variants are located in the ADH gene cluster and were identified previously in a candidate gene study involving some of these samples. The association between these three variants and UADT cancers was independently replicated in 5,092 UADT cancer cases and 6,794 controls non-overlapping samples presented here (rs1573496-ADH7, p = 5×10−8; rs1229984-ADH1B, p = 7×10−9; and rs698-ADH1C, p = 0.02). These results implicate two variants at 4q21 and 12q24 and further highlight three ADH variants in UADT cancer susceptibility.

Serum hyaluronan and collagen IV as non-invasive markers of liver fibrosis in patients from an endemic area for schistosomiasis mansoni: a field-based study in Brazil

Non-invasive markers of fibrosis have been used to diagnose liver fibrosis in a variety of diseases. Hyaluronic acid (HA) and collagen IV (C-IV) levels were measured in the sera of patients from an endemic area for schistosomiasis in Brazil to diagnose and to rank the intensity of liver fibrosis. Seventy-nine adult patients with schistosomiasis, in the age range of 21-82 years (49 ± 13.4) were submitted to clinical and ultrasonographic examinations. Ultrasound was employed to diagnose and categorise liver fibrosis according to World Health Organization patterns. Serum HA and C-IV levels were measured using commercial ELISA kits. Ultrasound revealed six patients with intense liver fibrosis, 21 with moderate, 23 with light and 29 without. Serum HA was able to separate individuals with fibrosis from those without (p < 0.001) and light from intense fibrosis (p = 0.029), but C-IV was not (p = 0.692). The HA diagnostic accuracy for fibrosis was 0.89. The 115.4 ng/mL cut-off level diagnosed patients with fibrosis (sensitivity 0.98, specificity 0.64). HA correlated positively with portal hypertension. Periportal fibrosis (subjective evaluation), age and collateral circulation predicted HA increase. In conclusion, we propose that serum HA can be used to identify patients with liver fibrosis in an endemic area for schistosomiasis mansoni in Brazil.

Genetic diversity of Leishmania infantum field populations from Brazil

Leishmania infantum (syn. Leishmania chagasi) is the etiological agent of visceral leishmaniasis (VL) in Brazil. The epidemiology of VL is poorly understood. Therefore, a more detailed molecular characterization at an intraspecific level is certainly needed. Herein, three independent molecular methods, multilocus microsatellite typing (MLMT), random amplification of polymorphic DNA (RAPD) and simple sequence repeats-polymerase chain reaction (SSR-PCR), were used to evaluate the genetic diversity of 53 L. infantum isolates from five different endemic areas in Brazil. Population structures were inferred by distance-based and Bayesian-based approaches. Eighteen very similar genotypes were detected by MLMT, most of them differed in only one locus and no correlation was found between MLMT profiles, geographical origin or the estimated population structure. However, complex profiles composed of 182 bands obtained by both RAPD and SSR-PCR assays gave different results. Unweighted pair group method with arithmetic mean trees built from these data revealed a high degree of homogeneity within isolates of L. infantum. Interestingly, despite this genetic homogeneity, most of the isolates clustered according to their geographical origin.

Field optimisation of MosquiTRAP sampling for monitoring Aedes aegypti Linnaeus (Diptera: Culicidae)

A sticky trap designed to capture gravid Aedes (Stegomyia) aegypti mosquitoes, MosquiTRAP, has been evaluated for monitoring this species in Brazil. However, the effects of trap densities on the capture rate of Ae. aegypti females and the sensitivity of vector detection are still unknown. After a preliminary study has identified areas of high and low female mosquito abundance, a set of experiments was conducted in four neighbourhoods of Belo Horizonte (state of Minas Gerais, Brazil) using densities of 1, 2, 4, 8, 16, 32 and 64 traps per block. Trap sensitivity (positive MosquiTRAP index) increased significantly when 1-8 MosquiTRAPs were installed per block in both high and low abundance areas. A strong fit was obtained for the total number of mosquitoes captured with increasing trap densities through a non-linear function (Box-Lucas) (r² = 0,994), which likely exhibits saturation towards an equilibrium level. The capacity of the Mean Female Aedes Index to distinguish between areas of high and low Ae. aegypti abundance was also investigated; the achieved differentiation was shown to be dependent on the MosquiTRAP density.

Fitness evaluation of two Brazilian Aedes aegypti field populations with distinct levels of resistance to the organophosphate temephos

In Brazil, decades of dengue vector control using organophosphates and pyrethroids have led to dissemination of resistance. Although these insecticides have been employed for decades against Aedes aegypti in the country, knowledge of the impact of temephos resistance on vector viability is limited. We evaluated several fitness parameters in two Brazilian Ae. aegypti populations, both classified as deltamethrin resistant but with distinct resistant ratios (RR) for temephos. The insecticide-susceptible Rockefeller strain was used as an experimental control. The population presenting the higher temephos resistance level, Aparecida de Goiânia, state of Goiás (RR95 of 19.2), exhibited deficiency in the following four parameters: blood meal acceptance, amount of ingested blood, number of eggs and frequency of inseminated females. Mosquitoes from Boa Vista, state of Roraima, the population with lower temephos resistance level (RR95 of 7.4), presented impairment in only two parameters, blood meal acceptance and frequency of inseminated females. These results indicate that the overall fitness handicap was proportional to temephos resistance levels. However, it is unlikely that these disabilities can be attributed solely to temephos resistance, since both populations are also resistant to deltamethrin and harbour the kdr allele, which indicates resistance to pyrethroids. The effects of reduced fitness in resistant populations are discussed.

Simultaneous EEG-fMRI at ultra-high field: Artifact prevention and safety assessment.

The simultaneous recording of scalp electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) can provide unique insights into the dynamics of human brain function, and the increased functional sensitivity offered by ultra-high field fMRI opens exciting perspectives for the future of this multimodal approach. However, simultaneous recordings are susceptible to various types of artifacts, many of which scale with magnetic field strength and can seriously compromise both EEG and fMRI data quality in recordings above 3T. The aim of the present study was to implement and characterize an optimized setup for simultaneous EEG-fMRI in humans at 7T. The effects of EEG cable length and geometry for signal transmission between the cap and amplifiers were assessed in a phantom model, with specific attention to noise contributions from the MR scanner coldheads. Cable shortening (down to 12cm from cap to amplifiers) and bundling effectively reduced environment noise by up to 84% in average power and 91% in inter-channel power variability. Subject safety was assessed and confirmed via numerical simulations of RF power distribution and temperature measurements on a phantom model, building on the limited existing literature at ultra-high field. MRI data degradation effects due to the EEG system were characterized via B0 and B1(+) field mapping on a human volunteer, demonstrating important, although not prohibitive, B1 disruption effects. With the optimized setup, simultaneous EEG-fMRI acquisitions were performed on 5 healthy volunteers undergoing two visual paradigms: an eyes-open/eyes-closed task, and a visual evoked potential (VEP) paradigm using reversing-checkerboard stimulation. EEG data exhibited clear occipital alpha modulation and average VEPs, respectively, with concomitant BOLD signal changes. On a single-trial level, alpha power variations could be observed with relative confidence on all trials; VEP detection was more limited, although statistically significant responses could be detected in more than 50% of trials for every subject. Overall, we conclude that the proposed setup is well suited for simultaneous EEG-fMRI at 7T.

Variation in haematological parameters in children less than five years of age with asymptomatic Plasmodium infection: implication for malaria field studies

During the season of high malaria transmission, most children are infected by Plasmodium, which targets red blood cells (RBCs), affecting haematological parameters. To describe these variations, we examined the haematological profiles of two groups of children living in a malaria-endemic area. A cross-sectional survey was conducted at the peak of the malaria transmission season in a rural area of Burkina Faso. After informed consent and clinical examination, blood samples were obtained from the participants for malaria diagnosis and a full blood count. Of the 414 children included in the analysis, 192 were not infected with Plasmodium, whereas 222 were asymptomatic carriers of Plasmodium infection. The mean age of the infected children was 41.8 months (range of 26.4-57.2) compared to 38.8 months (range of 22.4-55.2) for the control group (p = 0.06). The asymptomatic infected children tended to have a significantly lower mean haemoglobin level (10.8 g/dL vs. 10.4 g/dL; p < 0.001), mean lymphocyte count (4592/µL vs. 5141/µL; p = 0.004), mean platelet count (266 x 103/µL vs. 385 x 103/µL; p < 0.001) and mean RBC count (4.388 x 106/µL vs. 4.158 x 106/µL; p < 0.001) and a higher mean monocyte count (1403/µL vs. 1192/µL; p < 0.001) compared to the control group. Special attention should be applied when interpreting haematological parameters and evaluating immune responses in asymptomatic infected children living in malaria-endemic areas and enrolled in vaccine trials.

Monitoring resistance to Bacillus thuringiensis subsp. israelensis in the field by performing bioassays with each Cry toxin separately

Bacillus thuringiensis subsp. israelensis (Bti) is increasingly used worldwide for mosquito control and is the only larvicide used in the French Rhône-Alpes region since decades. The artificial selection of mosquitoes with field-persistent Bti collected in breeding sites from this region led to a moderate level of resistance to Bti, but to relatively high levels of resistance to individual Bti Cry toxins. Based on this observation, we developed a bioassay procedure using each Bti Cry toxin separately to detect cryptic Bti-resistance evolving in field mosquito populations. Although no resistance to Bti was detected in none of the three mosquito species tested (Aedes rusticus, Aedes sticticus and Aedes vexans), an increased tolerance to Cry4Aa (3.5-fold) and Cry11Aa toxins (8-fold) was found in one Ae. sticticus population compared to other populations of the same species, suggesting that resistance to Bti may be arising in this population. This study confirms previous works showing a lack of Bti resistance in field mosquito populations treated for decades with this bioinsecticide. It also provides a first panorama of their susceptibility status to individual Bti Cry toxins. In combination with bioassays with Bti, bioassays with separate Cry toxins allow a more sensitive monitoring of Bti-resistance in the field.