Search

Wolbachia are obligate intracellular bacteria that occur in insects and filarial worms. Strains that infect insects have genomes that encode mobile genetic elements, including diverse lambda-like prophages called Phage WO. Phage WO packages an approximately 65 kb viral genome that includes a unique eukaryotic association module, or EAM, that encodes unusually large proteins thought to mediate interactions between the bacterium, its virus, and the eukaryotic host cell. The Wolbachia supergroup B strain, w Stri from the planthopper Laodelphax striatellus , produces phage-like particles that can be recovered from persistently infected mosquito cells by ultracentrifugation. Illumina sequencing, assembly, and manual curation of DNA from two independent preparations converged on an identical 15,638 bp sequence that encoded packaging, assembly, and structural proteins. The absence of an EAM and regulatory genes defined for Phage WO from the wasp, Nasonia vitripennis, was consistent with the possibility that the 15,638 bp sequence represents an element related to a gene transfer agent (GTA), characterized by a signature head-tail region encoding structural proteins that package host chromosomal DNA. Future investigation of GTA function will be supported by the improved recovery of physical particles, electron microscopic examination of potential diversity among particles, and rigorous examination of DNA content by methods independent of sequence assembly.

Health care transition (HCT) describes the purposeful, planned movement of adolescents from child to adult-orientated care. The purpose of this qualitative study is to uncover the meaning of transition to adult-centered care as experienced by young adults with cerebral palsy (YA-CP) through the research question: What are the lived experiences of young adults with cerebral palsy transitioning from pediatric to adult healthcare? Six females and 3 males, aged 19-25 years of age, who identified as carrying the diagnosis of cerebral palsy without cognitive impairment, were interviewed. Giorgi's (1985) method for analysis of phenomenology was the framework for the study and guided the phenomenological reduction. The meaning of the lived experiences of YA-CPs transition to adult health care is expert novices with evidence and experience-based expectations, negotiating new systems interdependently and accepting less than was expected. More information and support is needed for the YA-CP during transition to ensure a well-organized move to appropriate adult-oriented health care that is considerate of the lifelong impact of the disorder. The nurses' role as advocate, mentor and guide can optimize the individual's response to the transition process., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Wolbachia is an obligate intracellular alphaproteobacterium that occurs in arthropod and nematode hosts. Wolbachia presumably provides a fitness benefit to its hosts, but the basis for its retention and spread in host populations remains unclear. Wolbachia genomes retain biosynthetic pathways for some vitamins, and the possibility that these vitamins benefit host cells provides a potential means of selecting for Wolbachia-infected cell lines. To explore whether riboflavin produced by Wolbachia is available to its host cell, we established that growth of uninfected C7-10 mosquito cells decreases in riboflavin-depleted culture medium. A well-studied inhibitor of riboflavin uptake, lumiflavin, further inhibits growth of uninfected C7-10 cells with an LC50 of approximately 12 μg/ml. Growth of C/wStr1 mosquito cells, infected with Wolbachia from the planthopper, Laodelphax striatellus, was enhanced in medium containing low levels of lumiflavin, but Wolbachia levels decreased. Lumiflavin-enhanced growth thus resembled the improved growth that accompanies treatment with antibiotics that deplete Wolbachia, rather than a metabolic advantage provided by the Wolbachia infection. We used the polymerase chain reaction to validate the decrease in Wolbachia abundance and evaluated our results in the context of a proteomic analysis in which we detected nearly 800 wStr proteins. Our data indicate that Wolbachia converts riboflavin to FMN and FAD for its own metabolic needs, and does not provide a source of riboflavin for its host cell.

Cultured cells provide an important in vitro system for examining metabolic interactions between the intracellular bacterium, Wolbachia pipientis, and its insect hosts. To test whether Wolbachia-associated changes in antioxidant activities could provide a tool to select for infected cells, we tested the effects of paraquat (PQ) on Aedes albopictus mosquito cells. Like mammalian cells, mosquito cells tolerate PQ over a wide range of concentrations, and for considerable lengths of time, depending on cell density at the time of treatment. When mosquito cells were plated at low density and allowed to grow in the presence of PQ, we measured an LC50 of approximately 1-2 μM. Unexpectedly, cells persistently infected with Wolbachia strain wStr, from the planthopper Laodelphax striatellus, grew to higher densities in the presence of 1.5 μM PQ than in its absence. This effect of PQ was similar to the improved growth of host cells that occurs in the presence of antibiotics that suppress the Wolbachia infection. A more detailed examination of growth and metabolic sensitivity indicated that wStr is about 10-fold more sensitive to PQ than the mosquito host cells. Microscopic examination confirmed that Wolbachia levels were reduced in PQ-treated cells, and DNA estimates based on the polymerase chain reaction (PCR) indicated that Wolbachia abundance decreased by approximately 100-fold over a 10-d period. Although Wolbachia genomes encode superoxide dismutase, inspection of annotated genomes indicates that they lack several genes encoding products that ameliorate oxidative damage, including catalase, which converts the PQ byproduct, hydrogen peroxide, to molecular oxygen and water. We suggest that loss of multiple genes that participate in repair of oxidative damage accounts for increased sensitivity of Wolbachia to PQ, relative to its host cells.

Context: As a multidimensional phenomenon, pain is influenced by various psychological factors. One such factor is catastrophizing, which is associated with higher pain intensity and emotional distress in cancer and noncancer pain. One possibility is that catastrophizing represents a general cognitive style that preferentially supports the processing of negative affective stimuli. Such preferential processing of threat--toward negative facial expressions, for example--is seen in emotional disorders and is sensitive to pharmacological treatment. Whether pharmacological (analgesic) treatment might also influence the processing of threat in pain patients is currently unclear., Objectives: This study investigates the effects catastrophizing on processing of facial affect in those receiving an acute opioid dose., Methods: In a double-blind crossover design, the performance of 20 palliative care patients after their usual dose of immediate-release opioid was compared with their performance following matched-placebo administration on a facial affect recognition (i.e., speed and accuracy) and threat-pain estimation task (i.e., ratings of pain intensity). The influence of catastrophizing was examined by splitting the sample according to their score on the Pain Catastrophizing Scale (PCS)., Results: Opioid administration had no effect on facial affect processing compared with placebo. However, the main finding was that enhanced processing of fear, sadness, and disgust was found only in patients who scored highly on the PCS. There was no difference in performance between the two PCS groups on the other emotions (i.e., happiness, surprise, and anger)., Conclusion: These findings suggest that catastrophizing is associated with an affective information-processing bias in patients with severe pain conditions., (Copyright © 2011 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.)

Fire suppression in Sierran ecosystems creates a substantial wildfire hazard and may exacerbate nutrient inputs into Lake Tahoe by allowing the buildup of O horizon material, which serves as a source for high N and P concentrations in runoff water. The purpose of this study was to evaluate the effects of biomass reduction using cut-to-length mechanical harvest followed by chipping and controlled burning on surface runoff volume and water quality. Based on previous findings regarding N and P leaching flux and soil solution concentrations, we hypothesized that controlled burning and/or mechanical harvest with residue chipping does not increase inorganic N, P, and S concentrations in overland flow. Runoff, snowmelt, and rainfall were collected, volume measurements were taken, and samples were analyzed for NO(3)-N, NH(4)-N, PO(4)-P, and SO(4). Runoff volume, season, and year were identified as important parameters influencing overland flow nutrient concentrations and loads. Higher nutrient concentrations were commonly associated with summer rather than winter runoff, but the opposite was true for nutrient loads due to the higher runoff volumes. Treatment (unharvested, harvested, unburned, burned) effect was a strong predictor for discharge loads of NO(3)-N and SO(4) but was a weak predictor for PO(4)-P. Discharge loads of NO(3)-N and SO(4) were greater for the unburned harvested and the burned unharvested treatments than for the unburned, unharvested control sites or the burned and harvested combined treatment. Although mechanical harvest and/or controlled burning had a small initial impact on increased nutrient loading, the effects were minimal compared with background levels. Hence, these management practices may have the potential to improve forest health without the danger of large-magnitude nutrient mobilization and degradation of runoff water quality found with wildfire.

High intensity wildfire due to long-term fire suppression and heavy fuels buildup can render watersheds highly susceptible to wind and water erosion. The 2002 "Gondola" wildfire, located just southeast of Lake Tahoe, NV-CA, was followed 2 wk later by a severe hail and rainfall event that deposited 7.6 to 15.2 mm of precipitation over a 3 to 5 h time period. This resulted in a substantive upland ash and sediment flow with subsequent down-gradient riparian zone deposition. Point measurements and ESRI ArcView were applied to spatially assess source area contributions and the extent of ash and sediment flow deposition in the riparian zone. A deposition mass of 380 Mg of ash and sediment over 0.82 ha and pre-wildfire surface bulk density measurements were used in conjunction with two source area assessments to generate an estimation of 10.1 mm as the average depth of surface material eroded from the upland source area. Compared to previous measurements of erosion during rainfall simulation studies, the erosion of 1800 to 6700 g m(-2) mm(-1) determined from this study was as much as four orders of magnitude larger. Wildfire, followed by the single event documented in this investigation, enhanced soil water repellency and contributed 17 to 67% of the reported 15 to 60 mm ky(-1) of non-glacial, baseline erosion rates occurring in mountainous, granitic terrain sites in the Sierra Nevada. High fuel loads now common to the Lake Tahoe Basin increase the risk that similar erosion events will become more commonplace, potentially contributing to the accelerated degradation of Lake Tahoe's water clarity.

High in situ concentrations of inorganic N and P have been reported in overland/litter interflow from Sierran forests, indicating that these nutrients are derived from the forest floor O horizons. To test this hypothesis, forest floor monoliths consisting of the combined O(e) and O(i) horizons were collected near the South Shore of Lake Tahoe, Nevada, for leaching experiments. Three monoliths were left intact, and three were hand-separated according to horizon for a total of three treatments (combined O(e)+O(i), O(e) only, and O(i) only) by three replications. Samples were randomized and placed into lined leaching bins. Initial leaching consisted of misting to simulate typical early fall precipitation. This was followed by daily snow applications and a final misting to simulate spring precipitation. Leachate was collected, analyzed for NH(4)(+)-N, NO(3)(-)-N, and PO(4)(3-)-P, and a nutrient balance was computed. There was a net retention of NH(4)(+)-N, but a net release of both NO(3)(-)-N and PO(4)(3-)-P, and a net release of inorganic N and P overall. Total contributions (mg) of N and P were highest from the O(e) and O(e)+O(i) combined treatments, but when expressed as per unit mass, significantly (p < 0.05) higher amounts of NO(3)(-)-N and PO(4)(3-)-P were derived from the O(i) materials. The nutrients in forest floor leachate are a potential source of biologically available N and P to adjacent surface waters. Transport of these nutrients from the terrestrial to the aquatic system in the Lake Tahoe basin may therefore play a part in the already deteriorating clarity of the lake.

With the introduction of Council Directive 97/43/Euratom, all member states should establish relevant diagnostic reference levels for X-ray examinations. Diagnostic reference levels help to facilitate standardisation and optimisation within departments and attempt to reduce dose variations between hospitals. High variation of individual patient doses for plain-film examinations by up to a factor of 75 was demonstrated by a previous Irish study, which highlighted the necessity for further investigation into other examinations in Ireland. The current work aimed to establish reference values for intravenous urography (IVU) examinations, an important contributor to collective dose. Eleven Irish hospitals were randomly selected, representing 30% of the total number of hospitals. Dose-area product (DAP) readings for IVUs were recorded along with technical and procedural details. Resultant data demonstrated mean hospital and individual patient DAP variations of a factor of 4 and 58, respectively. Stepwise regression analysis demonstrated that number of images taken, method of image acquisition and patient weight were the main causal agents for dose variations recorded. A proposed diagnostic reference level of 12 Gy cm(2) was established at the level of the third-quartile value of the mean hospital DAP values. This article provides evidence of large variations in DAP values for IVU examinations. It is hoped that application of the proposed DRL of 12 Gy cm(2 )will reduce the size of these variations.

Wide variations in patient dose for the same examinations have been demonstrated by several studies throughout Europe. By investigating patient dose, variations can be acknowledged, causal agents sought and the necessary adjustments made. Diagnostic reference levels (DRLs) provide a framework with which dose levels from individual hospitals are compared, and when exceeded, corrective actions can be taken where appropriate. This study aimed to establish DRLs for barium enema and barium meal examinations in Ireland. Measurements were recorded using a dose-area product meter in 12 hospitals representing 33% of relevant hospitals. Results demonstrated wide mean hospital dose variation, by up to a factor of 7.8 and 4.2 for barium enema and barium meal examinations, respectively. Minimum and maximum individual patient dose values varied by a factor of 45 for barium enemas and 90 for barium meal examinations. Reasons for dose variations were complex, but major factors for both examinations were fluoroscopy time, secondary radiation grid type and level of filtration. Some examination-specific factors were also noted. DRLs, established using the quantity dose-area product, were calculated to be 47 Gy cm(2) for barium enemas and 17 Gy cm(2) for barium meal examinations. Although the DRL value for barium meals was the same as the reference value established in the UK for that examination in 1996, the barium enema DRL in this study was 45% higher than the relevant UK value.

Objective: This study was undertaken to test the hypothesis that an inhibitor of uterine contractions acting at the level of the dihydropyridine receptor of the uterine L -type uterine calcium channel is released in greater amounts from fetal membranes before term than at term., Study Design: Endogenous calcium channel inhibitor activity was generated with standardized 25-cm2 surface area fetal membrane samples from the following 4 categories of women: preterm in labor, preterm not in labor, term in labor, and term not in labor. The amount of inhibitor in each membrane category was quantified by means of a competitive binding assay. Inhibition of uterine contractions induced by Bay K 8644 (an L -type calcium channel agonist) was used as another test of endogenous calcium channel inhibitor activity released from fetal membranes of all 4 groups of patients., Results: Endogenous calcium channel inhibitor activity was most variable but present in the greatest amount in fetal membranes of women who were preterm not in labor followed by those in women at term not in labor and at term in labor. Fetal membranes from women in preterm labor had the least amount of measured endogenous calcium channel inhibitor activity. Consistent with the competitive binding assay, endogenous calcium channel inhibitor activity from fetal membranes from women who were preterm not in labor, at term not in labor, and at term in labor inhibited Bay K 8644-induced uterine contractions. Fetal membranes from women in preterm labor did not inhibit Bay K 8644-induced contractions. Endogenous calcium channel inhibitor activity was present in the chorion, the decidua, and the placenta, with little activity in the amnion., Conclusion: The down-regulation of endogenous calcium channel inhibitor activity with advancing gestation is consistent with a potential role for this inhibitor in maintaining uterine quiescence and in regulating the transition into labor. One possible cause of idiopathic preterm labor may be an abnormally low amount of endogenous calcium channel inhibitor activity in fetal membranes.

This paper presents a review of empirical literature that deals with etiological factors in combat-related post-traumatic stress disorder (PTSD). Variables implicated in PTSD from three time frames, premilitary, military, and postmilitary, are identified, and findings from relevant research are discussed. There is consistency across studies in showing significant correlations between PTSD and combat exposure and post-military psychosocial adjustment. Less consistent are the findings with regard to relationships between premilitary psychosocial factors and PTSD. Recent findings from studies that have explored possible physiological correlates of PTSD also are discussed. Based on current literature, implications for future research on etiological factors in combat-related PTSD are presented.