Effect of effort-reward imbalance and burnout on infection control among Ecuadorian nurses.

BACKGROUND: Nurses are frequently exposed to transmissible infections, yet adherence to infection control measures is suboptimal. There has been inadequate research into how the psychosocial work environment affects compliance with infection control measures, especially in low- and middle-income countries. AIM: To examine the association between effort-reward imbalance, burnout and adherence to infection control measures among nurses in Ecuador. INTRODUCTION: A cross-sectional study linking psychosocial work environment indicators to infection control adherence. METHODS: The study was conducted among 333 nurses in four Ecuadorian hospitals. Self-administered questionnaires assessed demographic variables, perceived infection risk, effort-reward imbalance, burnout and infection control adherence. RESULTS: Increased effort-reward imbalance was found to be a unique incremental predictor of exposure to burnout, and burnout was a negative unique incremental predictor of nurses' self-reported adherence with infection control measures. DISCUSSION: Results suggest an effort-reward imbalance-burnout continuum, which, at higher levels, contributes to reduce adherence to infection control. The Ecuadorean government has made large efforts to improve universal access to health care, yet this study suggests that workplace demands on nurses remain problematic. CONCLUSION: This study highlights the contribution of effort-reward-imbalance-burnout continuum to the chain of infection by decreased adherence to infection control of nurses. IMPLICATIONS FOR NURSING POLICY: Health authorities should closely monitor the effect of new policies on psychosocial work environment, especially when expanding services and increasing public accessibility with limited resources. Additionally, organizational and psychosocial interventions targeting effort-reward imbalance and burnout in nurses should be considered part of a complete infection prevention and control strategy. Further study is warranted to identify interventions that best ameliorate effort-reward imbalance and burnout in low- and middle-income settings.

When the brain simulates stopping: Neural activity recorded during real and imagined stop-signal tasks.

It has been suggested that mental rehearsal activates brain areas similar to those activated by real performance. Although inhibition is a key function of human behavior, there are no previous reports of brain activity during imagined response cancellation. We analyzed event-related potentials (ERPs) and time-frequency data associated with motor execution and inhibition during real and imagined performance of a stop-signal task. The ERPs characteristic of stop trials-that is, the stop-N2 and stop-P3-were also observed during covert performance of the task. Imagined stop (IS) trials yielded smaller stop-N2 amplitudes than did successful stop (SS) and unsuccessful stop (US) trials, but midfrontal theta power similar to that in SS trials. The stop-P3 amplitude for IS was intermediate between those observed for SS and US. The results may be explained by the absence of error-processing and correction processes during imagined performance. For go trials, real execution was associated with higher mu and beta desynchronization over motor areas, which confirms previous reports of lower motor activation during imagined execution and also with larger P3b amplitudes, probably indicating increased top-down attention to the real task. The similar patterns of activity observed for imagined and real performance suggest that imagination tasks may be useful for training inhibitory processes. Nevertheless, brain activation was generally weaker during mental rehearsal, probably as a result of the reduced engagement of top-down mechanisms and limited error processing.

Freshwater fish faunas, habitats and conservation challenges in the Caribbean river basins of north-western South America.

The remarkable fish diversity in the Caribbean rivers of north-western South America evolved under the influences of the dramatic environmental changes of neogene northern South America, including the Quechua Orogeny and Pleistocene climate oscillations. Although this region is not the richest in South America, endemism is very high. Fish assemblage structure is unique to each of the four aquatic systems identified (rivers, streams, floodplain lakes and reservoirs) and community dynamics are highly synchronized with the mono-modal or bi-modal flooding pulse of the rainy seasons. The highly seasonal multispecies fishery is based on migratory species. Freshwater fish conservation is a challenge for Colombian environmental institutions because the Caribbean trans-Andean basins are the focus of the economic development of Colombian society, so management measures must be directed to protect aquatic habitat and their connectivity. These two management strategies are the only way for helping fish species conservation and sustainable fisheries.

HDLive ultrasound images of ovarian dermoid cysts: diagnostic accuracy.

OBJECTIVE: To demonstrate that the use of 3D/4D HDLive increases the image quality in the diagnosis of benign cystic ovarian teratomas. MATERIALS AND METHODS: 3D/HDLive ultrasound (US) was used in 31 cases of suspected ovarian cystic teratoma using vaginal 2D US. The following pathognomonic images of mature cystic teratomas were considered for diagnosis: 1) a cystic, unilocular lesion with a densely echogenic tubercle (Rokitansky nodule); 2) a diffuse or partially echogenic mass usually demonstrating sound attenuation; 3) fluid-fluid/fat-fluid levels; 4) dermoid mesh with hyperechogenic calcifications indicating the presence of bone, teeth, or other ectodermally-derived structure; 5) multiple mobile spherical structures (fat globules). RESULTS: Dermoids present a wide spectrum of images depending on the predominant tissue type. In the vast majority of cases there are dense echogenic structures that correspond to complex masses of fatty tissue, sebum, hair, epithelial remnants, along with cartilage or bone. If we catalogue all the images together, the pathognomonic of dermoid are: 1) cystic or solid cystic lesions with a Rokitansky nodule, with bone, teeth or cartilage (six cases, 22.2%); 2) a solid mass with or without attenuation that corresponds with pure sebum (five cases, 18.5%); 3) a diffuse mass with fine bands that correspond with hair inside sebum (four cases, 12.9%) and that may form meshes or plugs corresponding with a mixture of fat, sebum, and hair (three cases, 11.5%). CONCLUSIONS: HDLive U.S. provides some images of exceptional quality that enhance the definition of the structures of these tumors (fat, hair, cartilage, bone, etc.) compared to 2D/3D/4D.

Involvement of G protein and purines in Rhinella arenarum oocyte maturation.

We investigated the participation of G(αi) protein and of intracellular cAMP levels on spontaneous and progesterone-mediated maturation in Rhinella arenarum fully grown follicles and denuded oocytes. Although progesterone is the established maturation inducer in amphibians, Rhinella arenarum oocytes obtained during the reproductive period (competent oocytes) resume meiosis with no need for an exogenous hormonal stimulus if deprived of their enveloping follicular cells, a phenomenon called spontaneous maturation. In amphibian oocytes, numerous signalling mechanisms have been involved in the rapid, non-genomic, membrane effects of progesterone, but most of these are not fully understood. The data presented here demonstrate that activation of the G(αi) protein by Mas-7 induced maturation in non-competent oocytes and also an increase in GVBD (germinal vesicle breakdown) in competent oocytes. Similar results were obtained with intact follicles independent of the season. The activation of adenylyl cyclase (AC) by forskolin seems to inhibit both spontaneous and progesterone-induced GVBD. In addition, the high intracellular levels of cAMP caused by activation of AC by forskolin treatment or addition of db-cAMP inhibited maturation that had been induced by Mas-7 and in a dose-dependent manner. Treatment with H-89, a protein kinase A (PKA) inhibitor, was able to trigger GVBD in a dose-dependent manner in non-competent oocytes and increased the percentages of GVBD in oocytes competent to mature spontaneously. The results obtained with whole follicles and denuded oocytes were similar, which suggested that effects on AC and PKA were not mediated by follicle cells. The fact that Mas-7 was able to induce maturation in non-competent oocytes in a similar manner to progesterone and to increase spontaneous maturation suggests that G(αi) activation could be an important step in meiosis resumption. Thus, the decrease in cAMP as a result of the regulation of the G proteins on AC and the inactivation of PKA by H-89 could contribute to the activation of MPF (maturation promoting factor) and induce maturation of the oocytes of Rhinella arenarum.

Role of phospholipase A2 pathway in regulating activation of Bufo arenarum oocytes.

Transient increases in the concentration of cytosolic Ca(2+) are essential for triggering egg activation events. Increased Ca(2+) results from its rapid release from intracellular stores, mainly mediated by one or both intracellular calcium channels: the inositol trisphosphate receptor (IP3R) and the ryanodine receptor (RyR). Several regulatory pathways that tailor the response of these channels to the specific cell type have been proposed. Among its many modulatory actions, calcium can serve as an activator of a cytosolic phospholipase A(2) (cPLA2), which releases arachidonic acid from phospholipids of the endoplasmic reticulum as well as from the nuclear envelope. Previous studies have suggested that arachidonic acid and/or its metabolites were able to modulate the activity of several ion channels. Based on these findings, we have studied the participation of the phospholipase A(2) (PLA(2)) pathway in the process of Bufo arenarum oocyte activation and the interrelation between any of its metabolites and the ion channels involved in the calcium release from the intracellular reservoirs at fertilization. We found that addition of both melittin, a potent PLA(2) activator, and arachidonic acid, the main PLA(2) reaction metabolite, was able to induce activation events in a bell-shaped manner. Differential regulation of IP3Rs and RyRs by arachidonic acid and its products could explain melittin and arachidonic acid behaviour in Bufo arenarum egg activation. The concerted action of arachidonic acid and/or its metabolites could provide controlled mobilization of calcium from intracellular reservoirs and useful tools for understanding calcium homeostasis in eggs that express both types of receptors.

Analysis of exosome release and its prognostic value in human colorectal cancer.

A significant proportion of extracellular nucleic acids in plasma circulate highly protected in tumor-specific exosomes, but it is unclear how the release of exosomes is modulated in carcinogenesis. We quantified by cytometry exosomes in plasma of 91 colorectal cancer patients to evaluate their potential as a tumor indicator and their repercussions on diagnosis and prognosis. We examined the involvement of TSAP6, a TP53-regulated gene involved in the regulation of vesicular secretion, in levels of circulating exosomes in plasma of colorectal patients and in HCT116 TP53-(wild-type and null) human colorectal cancer cell lines. The fraction of exosomes in cancer patients was statistically higher than in healthy controls (mean rank » 53.93 vs. 24.35). High levels of exosomes in plasma of patients correlated with high levels of carcino-embryonic antigen (P » 0.029) and with poorly differentiated tumors (P » 0.039) and tended to have shorter overall survival than patients with low levels (P » 0.056). Release of exosomes did not correlate with TSAP6 expression; and regulation of TSAP6 by TP53 was not shown either in tumor samples or in HCT116 cell lines. Although it was not suggested that the TP53/TSAP6 pathway regulates the release of exosomes into the plasma of colorectal cancer patients, the level of circulating exosomes may be used as a tumor indicator, because it correlates with poor prognosis parameters and shorter survival.

Semi-automatic Sono T measurement of nuchal translucency.

A prospective study of 63 singleton pregnancies between 11 + 0 and 13 + 6 weeks gestation underwent semi-automatic nuchal translucency (NT) measurement and were compared with two-dimensional ultrasonography (2D US). Inter-observer variation and the repeatability were evaluated. Sono T automatically achieves mid-sagittal plane views and measures the maximum NT thickness. Measurements have less inter-observer variation (CI = -0.13, -0.04) when compared with 2D measurements (CI = -0.45, 0.28). It is reproducible and comparable to conventional 2D US technique for NT measurement. However, incorporating Sono T into routine practice requires further program refinements in order to reduce erroneous NT measurements.

Investigating the effect of synthesis selection on O3-sodium layered oxide structural changes and electrochemical properties.

Transition metal (TM) layered oxides constitute a promising family of materials for use in Na-ion battery cathodes. Here O3-Na (Ni1/3Mn1/3Fe1/3) O2 was synthesised using optimised sol-gel and solid-state routes, and the physico- and electrochemical natures of the resulting materials were thoroughly studied. Significant differences in electrochemical behaviour were observed, and the use of in operando XRD determined this stemmed from the suppression of the P3 phase in the sol-gel material during cycling. This was attributable to differences in the degree of transition metal migration in the materials ensuing from the selection of synthetic route. This demonstrates that not only the choice of material, but also that of synthesis route, can have dramatic impact on the resulting structural and electrochemical nature, making such considerations critical in the future development of advanced Na-ion cathode materials.

Mechanism of localization of the magnetization reversal in 3 nm wide Co nanowires.

The mechanism of magnetization reversal has been studied in a model system of self-assembled cobalt nanowires with a 3 nm diameter. The structure, orientation and size of grains within the nanowires could be determined by high resolution transmission electron microscopy. The magnetic properties were probed using static and dynamic magnetization measurements. Micromagnetic modeling based on the structural analysis allows us to correlate the structure and the magnetic behavior of the wires, revealing competition between shape anisotropy, magnetocrystalline anisotropy and exchange in the localized reversal within Co hcp oriented grains. These results provide direct experimental evidence of the link between anisotropy fluctuations and reversal localization in nanowires.

Predicting ovarian reserve and reproductive outcome using antimüllerian hormone (AMH) and antral follicle count (AFC) in patients with previous assisted reproduction technique (ART) failure.

PURPOSE OF INVESTIGATION: The main objective of our prospective, observational, analytical research work was to determine whether Anti-Müllerian hormone (AMH) and antral follicle count (AFC) could be effectively used as predictors of ovarian reserve and, possibly, of reproductive outcome with ART. METHODS: We studied 143 IVF/ET cycles in patients with a previous history of ART failure, all of them supposed to be of poor prognosis, who had agreed to another ART attempt after knowing their AMH, AFC, and base hormone (FSH, LH, 17 beta-estradiol) levels. RESULTS: AMH and AFC showed a positive correlation with the number of oocytes retrieved (p = 0.0016) and (p < 0.0001), respectively and with percentage of MII oocytes, (p = 0.00756) and (p < 0.001). The combined use of these markers showed an area under the curve of 82.2% for oocytes retrieved. Our results shows a very high cancelation (22% of started cycles) and very low pregnancy rates (6.7% and 9.8%) in low and normoresponders, respectively. CONCLUSIONS: AMH levels and AFC are reliable indicators of ovarian reserve. Patients with ovarian reserve levels that predict a very low probability of success should be informed that the poor prognosis associated with these values may not justify the expense of IVF/ET.

Vesicle-related microRNAs in plasma of nonsmall cell lung cancer patients and correlation with survival.

The identification of tumour biomarkers that detect the presence of disease using noninvasive diagnostic procedures is a key part of cancer research. We determined in plasma the vesicle-related microRNA (miRNA) expression profile of nonsmall cell lung cancer (NSCLC) and evaluate whether plasma miRNAs can be both discriminating (between patients and healthy controls) and prognostic markers. 365 human miRNAs were analysed by Taqman® low-density arrays (Applied Biosystems, Foster City, CA, USA) in the plasma from 28 NSCLC patients and 20 controls. Five selected miRNAs (let-7f, miR-20b, miR-30e-3p, miR-223 and miR-301) were validated independently by real-time PCR in plasma from 78 NSCLC and 48 controls and correlated with pathologic parameters and survival. Levels of let-7f, miR-20b and miR-30e-3p were decreased in plasma vesicles of NSCLC patients. Moreover, levels of let-7f and miR-30e-3p distinguished between two groups of patients for stage of disease and therefore possibility of surgery. Plasma levels of miR-30e-3p and let-7f were associated with short disease-free survival and overall survival, respectively. NSCLC patients and healthy controls differ in vesicle-related miRNAs in plasma. Levels of let-7f and miR-30e-3p in NSCLC patients are associated with poor outcome. Thus, plasma vesicle-related miRNAs obtained by noninvasive methods could serve as circulating tumour biomarkers of discriminating and prognostic value.

Participation of inositol trisphosphate and ryanodine receptors in Bufo arenarum oocyte activation.

Calcium is considered the most important second messenger at fertilization. Transient release from intracellular stores is modulated through both agonist-gated channels, IP3Rs and RyRs, which can be found individually or together depending on the oocyte species. Using the four commonly used compounds (thimerosal, caffeine, heparin and ruthenium red), we investigated the existence and interdependence of both IP3Rs and RyRs in mature Bufo arenarum oocytes. We found that caffeine, a well known specific RyRs agonist, was able to trigger oocyte activation in a dose-dependent manner. Microinjection of 10 mM caffeine showed 100% of oocytes exhibiting characteristic morphological criteria of egg activation. Ruthenium red, the specific RyR blocker, was able to inhibit oocyte activation induced either by sperm or caffeine. Our present findings provide the first reported evidence of the existence of RyR in frogs. We further explored the relationship between IP3Rs and RyRs in B. arenarum oocytes by exposing them to the agonists of one class after injecting a blocker of the other class of receptor. We found that thimerosal overcame the inhibitory effect of RyR on oocyte activation, indicating that IP3Rs function as independent receptors. In contrast, previous injection of heparin delayed caffeine-induced calcium release, revealing a relative dependence of RyRs on functional IP3Rs, probably through a CICR mechanism. Both receptors play a role in Ca²+ release mechanisms although their relative contribution to the activation process is unclear.

Participation of MAPK, PKA and PP2A in the regulation of MPF activity in Bufo arenarum oocytes.

The objectives of the present paper were to study the involvement and possible interactions of both cAMP-PKA and protein phosphatases in Bufo arenarum oocyte maturation and to determine if these pathways are independent or not of the MAP kinase (MAPK) cascade. Our results indicated that the inhibition of PKA by treatment with H-89, an inhibitor of the catalytic subunit of PKA, was capable of inducing GVBD in a dose-dependent manner by a pathway in which Cdc25 phosphatase but not the MAPK cascade is involved. The injection of 50 nl of H-89 10 µM produced GVBD percentages similar to those obtained with treatment with progesterone. In addition, the assays with okadaic acid (OA), a PP2A inhibitor, significantly enhanced the percentage of oocytes that resumed meiosis by a signal transducing pathway in which the activation of the MEK-MAPK pathway is necessary, but in which Cdc25 phosphatase was not involved. Treatment with H-89, was able to overcome the inhibitory effect of PKA on GVBD; however, the inhibition of Cdc25 activity with NaVO3 was able to overcome the induction of GVBD by H-89. Although the connections between PKA and other signalling molecules that regulate oocytes maturation are still unclear, our results suggest that phosphatase Cdc25 may be the direct substrate of PKA. In Xenopus oocytes it was proposed that PP2A, a major Ser/Thr phosphatase present, is a negative regulator of Cdc2 activation. However, in Bufo arenarum oocytes, inhibition of Cdc25 with NaVO3 did not inhibit OA-induced maturation, suggesting that the target of PP2A was not the Cdc25 phosphatase. MAPK activation has been reported to be essential in Xenopus oocytes GVBD. In B. arenarum oocytes we demonstrated that the inhibition of MAPK by PD 98059 prevented the activation of MPF induced by OA, suggesting that the activation of the MAPK cascade produced an inhibition of Myt1 and, in consequence, the activation of MPF without participation of the Cdc25 phosphatase. Our results suggest that in incompetent oocytes of B. arenarum two signal transduction pathways may be involved in the control of MPF activation: (1) the inhibition of phosphatase 2A that through the MEK-MAPK pathway regulates the activity of the Myt1; and (2) the inhibition of AMPc-PKA, which affects the activity of the Cdc25 phosphatase.

Immunochemical and molecular characterization of regulatory idiotopes expressed by monoclonal antibodies exhibiting or lacking beta 2-6 fructosan binding activity.

Hybridomas secreting antibodies bearing the ABPC48 (A48) regulatory idiotype (Id) were generated from BALB/c mice treated at birth or as adults with minute amounts of anti-A48-Id antibodies. The majority of these antibodies were recognized by the syngeneic monoclonal anti-A48-Id and anti-UPC-10-Id antibodies, IDA10 and 10-1, respectively. In Northern blotting experiments, most of these hybridomas were shown to use VH (heavy chain variable region) genes related to the 441-4 germline VH gene that encodes the A48 VH region. Hybridization was detected between polyadenylated H chain mRNA, isolated from the majority of the hybridomas, and the VH probe. Southern blots confirmed these results by showing a rearrangement of VH-related sequences to the JH (H chain joining segment) clusters on these same hybridomas. The antibodies from all of the hybridomas that derived from neonatal mice and half of those derived from adult mice showed specificity for fructosan determinants that, in most cases, was different from the beta 2-6 fructosan linkage specificity of A48. Surprisingly, several of the non-fructosan-binding hybridomas generated from the adult mice and the MOPC-173 myeloma demonstrated a clear specificity for the beta 1-6-D-galactan determinant. Of four galactan-binding myeloma proteins studied. XRPC 44 alone shared idiotypy with the UPC-10 myeloma. These findings suggest a possible clonal crossreactive regulation mediated by regulatory idiotopes. The crossreactive regulation concept is discussed.

Primary immunodeficiency diseases: a practical guide for clinicians.

Primary immunodeficiency diseases (PIDs) are genetically determined disorders of the immune system resulting in greatly enhanced susceptibility to infectious disease, autoimmunity and malignancy. While individual PIDs are rare, as a group, it is estimated that between 1:2000 and 1:10 000 live births are affected by a PID. Moreover, PIDs can present at any age from birth to adulthood, posing a considerable challenge for the practising physician to know when and how to work-up a patient for a possible immune defect. In this review, we outline the basic organisation of the human immune system and the types of infections that occur when elements of the immune system are dysfunctional. Importantly, we provide practical guidelines for identifying patients who should be referred for assessment of possible immunodeficiency and an overview of screening investigations and effective therapeutic options available for these patients.

Effect of the stop-signal modality on brain electrical activity associated with suppression of ongoing actions.

To clarify how the modality of stop signals affects the ability to suppress ongoing actions, we compared behavioural indices and event-related potentials (ERPs) recorded in healthy volunteers performing visual and auditory stop-signal tasks. Auditory stop signals were associated with faster reaction times and shorter stop-N2 and stop-P3 latencies. Given that the tasks did not differ in attentional/arousal processes (go-P3 or stop-P3 amplitudes) or motor preparation (LRP amplitude, onset or latency), our results suggest that stop signal modality mainly affects bottom-up sensory processes (faster auditory processing). The ERP waveform obtained by subtracting successfully stopped from unsuccessfully stopped trials showed similar amplitude and topography in both tasks, indicating that the strength of top-down processes related to inhibition was independent of modality. The findings contribute further knowledge about the variables associated with efficient inhibition and have practical implications for the design of settings or interventions to improve reactive inhibition.

Enhanced Data Covariance Estimation Using Weighted Combination of Multiple Gaussian Kernels for Improved M/EEG Source Localization.

In the recent past, estimating brain activity with magneto/electroencephalography (M/EEG) has been increasingly employed as a noninvasive technique for understanding the brain functions and neural dynamics. However, one of the main open problems when dealing with M/EEG data is its non-Gaussian and nonstationary structure. In this paper, we introduce a methodology for enhancing the data covariance estimation using a weighted combination of multiple Gaussian kernels, termed WM-MK, that relies on the Kullback-Leibler divergence for associating each kernel weight to its relevance. From the obtained results of validation on nonstationary and non-Gaussian brain activity (simulated and real-world EEG data), WM-MK proves that the accuracy of the source estimation raises by more effectively exploiting the measured nonlinear structures with high time and space complexity.