2,555 research outputs found
Association between congenital toxoplasmosis and preterm birth, low birthweight and small for gestational age birth.
OBJECTIVE: To determine the association between congenital toxoplasmosis and preterm birth, low birthweight and small for gestational age birth. DESIGN: Multicentre prospective cohort study. SETTING: Ten European centres offering prenatal screening for toxoplasmosis. POPULATION: Deliveries after 23 weeks of gestation in 386 women with singleton pregnancies who seroconverted to toxoplasma infection before 20 weeks of gestation. Deliveries after 36 weeks in 234 women who seroconverted at 20 weeks or later, and tested positive before 37 weeks. METHODS: Comparison of infected and uninfected births, adjusted for parity and country of birth. MAIN OUTCOME MEASURES: Differences in gestational age at birth, birthweight and birthweight centile. RESULTS: Infected babies were born or delivered earlier than uninfected babies: the mean difference for seroconverters before 20 weeks was -5.4 days (95% CI: -1.4, -9.4), and at 20 weeks or more, -2.6 days (95% CI: -0.5, -4.7). Congenital infection was associated with an increased risk of preterm delivery when seroconversion occurred before 20 weeks (OR 4.71; 95% CI: 2.03, 10.9). No significant differences were detected for birthweight or birthweight centile. CONCLUSION: Babies with congenital toxoplasmosis were born earlier than uninfected babies but the mechanism leading to shorter length of gestation is unknown. Congenital infection could precipitate early delivery or prompt caesarean section or induction of delivery. We found no evidence for a significant association between congenital toxoplasmosis and reduced birthweight or small for gestational age birth
Short-term chilled storage of zebrafish (Danio rerio) embryos in cryoprotectant as an alternative to cryopreservation.
As zebrafish embryos have never been cryopreserved, we developed a protocol to store zebrafish embryos (50% epiboly-5.3 hour post fertilization) for up to 18 h at 0°C. Initial experiments to optimize the cryoprotectant (CPA) solution demonstrated improved embryo hatching rate following chilling at 0°C for 18 h with 1 M MeOH+0.1 M sucrose (56 ± 5%) compared with other combinations of methanol (0.2-0.5 M) and sucrose (0.05-0.1 M). This combination of CPAs that protects against chilling injury was further tested to assess its impact on sox gene and protein expression. Significant decreases in sox3 gene expression were observed in hatched embryos that had been chilled for 18 h in 1 M MeOH+0.1 sucrose compared with non-chilled controls, however the expression of both sox2 and sox3 proteins was unaffected. Significant decreases in sox2 protein expression were, however, observed in embryos that had been chilled without CPAs and these embryos also had lower hatching rates than those chilled with the optimal CPA solution. We, therefore, conclude that the CPA combination of 1 M MeOH+0.1 M sucrose facilitates chilled storage of early stage (50% epiboly) zebrafish embryos for up to 18 h without compromising transcriptional response
The study of applying heat to enhance moisture transfer in knitted spacer structures
The aim of the article is to report the research of the Advanced Textiles Research Group on the application of heat to enhance the moisture transmission in knitted spacer structures. The current trend in the design and development of moisture management textiles is to use knitted spacer structures. Generally, in moisture management textiles, the moisture is transmitted through the fabric due to capillary forces, which are influenced by the hydrostatic pressure difference between the two fabric layers and the geometry and the dimensions of the capillaries of the sandwiched fibre layer of a knitted spacer structures. However, the hydrostatic pressure difference is also influenced by the outer environmental changes. The research has demonstrated that the moisture transfer rate of up to 30% per 100 cm2 of fabric area can be achieved by creating a temperature gradient between the two layers of a knitted spacer structures. This temperature gradient was achieved by application of heat at one layer of the knitted spacer structures, which influenced the hydrostatic pressure difference of the knitted spacer structures. Application of heat to the knitted spacer structures was achieved by knitting small heater elements on side of knitted spacer structures to create an active moisture management structure. Wash tests, temperature rise rates and moisture wettability experiments of the active moisture management structure were performed, and the results are discussed in the publication
The role of asymmetric interactions on the effect of habitat destruction in mutualistic networks
Plant-pollinator mutualistic networks are asymmetric in their interactions:
specialist plants are pollinated by generalist animals, while generalist plants
are pollinated by a broad involving specialists and generalists. It has been
suggested that this asymmetric ---or disassortative--- assemblage could play an
important role in determining the equal susceptibility of specialist and
generalist plants under habitat destruction. At the core of the argument lies
the observation that specialist plants, otherwise candidates to extinction,
could cope with the disruption thanks to their interaction with generalist
pollinators. We present a theoretical framework that supports this thesis. We
analyze a dynamical model of a system of mutualistic plants and pollinators,
subject to the destruction of their habitat. We analyze and compare two
families of interaction topologies, ranging from highly assortative to highly
disassortative ones, as well as real pollination networks. We found that
several features observed in natural systems are predicted by the mathematical
model. First, there is a tendency to increase the asymmetry of the network as a
result of the extinctions. Second, an entropy measure of the differential
susceptibility to extinction of specialist and generalist species show that
they tend to balance when the network is disassortative. Finally, the
disappearance of links in the network, as a result of extinctions, shows that
specialist plants preserve more connections than the corresponding plants in an
assortative system, enabling them to resist the disruption.Comment: 14 pages, 7 figure
An early Cambrian agglutinated tubular lophophorate with brachiopod characters.
The morphological disparity of lophotrochozoan phyla makes it difficult to predict the morphology of the last common ancestor. Only fossils of stem groups can help discover the morphological transitions that occurred along the roots of these phyla. Here, we describe a tubular fossil Yuganotheca elegans gen. et sp. nov. from the Cambrian (Stage 3) Chengjiang Lagerstätte (Yunnan, China) that exhibits an unusual combination of phoronid, brachiopod and tommotiid (Cambrian problematica) characters, notably a pair of agglutinated valves, enclosing a horseshoe-shaped lophophore, supported by a lower bipartite tubular attachment structure with a long pedicle with coelomic space. The terminal bulb of the pedicle provided anchorage in soft sediment. The discovery has important implications for the early evolution of lophotrochozoans, suggesting rooting of brachiopods into the sessile lophotrochozoans and the origination of their bivalved bauplan preceding the biomineralization of shell valves in crown brachiopods
Population-based estimates of the prevalence of FMR1 expansion mutations in women with early menopause and primary ovarian insufficiency
PURPOSE: Primary ovarian insufficiency before the age of 40 years affects 1% of the female population and is characterized by permanent cessation of menstruation. Genetic causes include FMR1 expansion mutations. Previous studies have estimated mutation prevalence in clinical referrals for primary ovarian insufficiency, but these are likely to be biased as compared with cases in the general population. The prevalence of FMR1 expansion mutations in early menopause (between the ages of 40 and 45 years) has not been published. METHODS: We studied FMR1 CGG repeat number in more than 2,000 women from the Breakthrough Generations Study who underwent menopause before the age of 46 years. We determined the prevalence of premutation (55–200 CGG repeats) and intermediate (45–54 CGG repeats) alleles in women with primary ovarian insufficiency (n = 254) and early menopause (n = 1,881). RESULTS: The prevalence of the premutation was 2.0% in primary ovarian insufficiency, 0.7% in early menopause, and 0.4% in controls, corresponding to odds ratios of 5.4 (95% confidence interval = 1.7–17.4; P = 0.004) for primary ovarian insufficiency and 2.0 (95% confidence interval = 0.8–5.1; P = 0.12) for early menopause. Combining primary ovarian insufficiency and early menopause gave an odds ratio of 2.4 (95% confidence interval = 1.02–5.8; P = 0.04). Intermediate alleles were not significant risk factors for either early menopause or primary ovarian insufficiency. CONCLUSION: FMR1 premutations are not as prevalent in women with ovarian insufficiency as previous estimates have suggested, but they still represent a substantial cause of primary ovarian insufficiency and early menopause
Occupational and leisure time physical activity in contrasting relation to ambulatory blood pressure
Background: While moderate and vigorous leisure time physical activities are well documented to decrease the risk for cardiovascular disease, several studies have demonstrated an increased risk for cardiovascular disease in workers with high occupational activity. Research on the underlying causes to the contrasting effects of occupational and leisure time physical activity on cardiovascular health is lacking. The aim of this study was to examine the relation of objective and self-report measures of occupational and leisure time physical activity with 24-h ambulatory systolic blood pressure (BP).
Methods: Results for self-reported physical activity are based on observations in 182 workers (60% male, mean age 51 years), while valid objective physical activity data were available in 151 participants. The usual level of physical activity was assessed by 5 items from the Job Content Questionnaire (high physical effort, lifting heavy loads, rapid physical activity, awkward body positions and awkward positions of head or arms at work) and one item asking about the general level of physical activity during non-working time. On a regular working day, participants wore an ambulatory BP monitor and an accelerometer physical activity monitor during 24 h. Associations were examined by means of Analysis of Covariance.
Results: Workers with an overall high level of self-reported occupational physical activity as well as those who reported to often lift heavy loads at work had a higher mean systolic BP at work, at home and during sleep. However, no associations were observed between objectively measured occupational physical activity and BP. In contrast, those with objectively measured high proportion of moderate and vigorous leisure time physical activity had a significantly lower mean systolic BP during daytime, while no differences were observed according to self-reported level of leisure time physical activity.
Conclusions: These findings suggest that workers reporting static occupational physical activities, unlike general physically demanding tasks characterized by dynamic movements of large muscle groups, are related to a higher daily systolic BP, while high objective levels of moderate and vigorous leisure time physical activity are related to lower daytime systolic BP. Ambulatory systolic BP may be a physiological explanatory factor for the contrasting effects of occupational and leisure time physical activity
BAC-FISH refutes report of an 8p22–8p23.1 inversion or duplication in 8 patients with Kabuki syndrome
BACKGROUND: Kabuki syndrome is a multiple congenital anomaly/mental retardation syndrome. The syndrome is characterized by varying degrees of mental retardation, postnatal growth retardation, distinct facial characteristics resembling the Kabuki actor's make-up, cleft or high-arched palate, brachydactyly, scoliosis, and persistence of finger pads. The multiple organ involvement suggests that this is a contiguous gene syndrome but no chromosomal anomalies have been isolated as an etiology. Recent studies have focused on possible duplications in the 8p22–8p23.1 region but no consensus has been reached. METHODS: We used bacterial artificial chromosome-fluorescent in-situ hybridization (BAC-FISH) and G-band analysis to study eight patients with Kabuki syndrome. RESULTS: Metaphase analysis revealed no deletions or duplications with any of the BAC probes. Interphase studies of the Kabuki patients yielded no evidence of inversions when using three-color FISH across the region. These results agree with other research groups' findings but disagree with the findings of Milunsky and Huang. CONCLUSION: It seems likely that Kabuki syndrome is not a contiguous gene syndrome of the 8p region studied
Association between canine leishmaniosis and Ehrlichia canis co-infection: a prospective case-control study
Abstract Background In the Mediterranean basin, Leishmania infantum is a major cause of disease in dogs, which are frequently co-infected with other vector-borne pathogens (VBP). However, the associations between dogs with clinical leishmaniosis (ClinL) and VBP co-infections have not been studied. We assessed the risk of VBP infections in dogs with ClinL and healthy controls. Methods We conducted a prospective case-control study of dogs with ClinL (positive qPCR and ELISA antibody for L. infantum on peripheral blood) and clinically healthy, ideally breed-, sex- and age-matched, control dogs (negative qPCR and ELISA antibody for L. infantum on peripheral blood) from Paphos, Cyprus. We obtained demographic data and all dogs underwent PCR on EDTA-blood extracted DNA for haemoplasma species, Ehrlichia/Anaplasma spp., Babesia spp., and Hepatozoon spp., with DNA sequencing to identify infecting species. We used logistic regression analysis and structural equation modelling (SEM) to evaluate the risk of VBP infections between ClinL cases and controls. Results From the 50 enrolled dogs with ClinL, DNA was detected in 24 (48%) for Hepatozoon spp., 14 (28%) for Mycoplasma haemocanis, 6 (12%) for Ehrlichia canis and 2 (4%) for Anaplasma platys. In the 92 enrolled control dogs, DNA was detected in 41 (45%) for Hepatozoon spp., 18 (20%) for M. haemocanis, 1 (1%) for E. canis and 3 (3%) for A. platys. No Babesia spp. or “Candidatus Mycoplasma haematoparvum” DNA was detected in any dog. No statistical differences were found between the ClinL and controls regarding age, sex, breed, lifestyle and use of ectoparasitic prevention. A significant association between ClinL and E. canis infection (OR = 12.4, 95% CI: 1.5–106.0, P = 0.022) was found compared to controls by multivariate logistic regression. This association was confirmed using SEM, which further identified that younger dogs were more likely to be infected with each of Hepatozoon spp. and M. haemocanis, and dogs with Hepatozoon spp. were more likely to be co-infected with M. haemocanis. Conclusions Dogs with ClinL are at a higher risk of co-infection with E. canis than clinically healthy dogs. We recommend that dogs diagnosed with ClinL should be tested for E. canis co-infection using PCR
Modulation of emotional appraisal by false physiological feedback during fMRI
BACKGROUND
James and Lange proposed that emotions are the perception of physiological reactions. Two-level theories of emotion extend this model to suggest that cognitive interpretations of physiological changes shape self-reported emotions. Correspondingly false physiological feedback of evoked or tonic bodily responses can alter emotional attributions. Moreover, anxiety states are proposed to arise from detection of mismatch between actual and anticipated states of physiological arousal. However, the neural underpinnings of these phenomena previously have not been examined.
METHODOLOGY/PRINCIPAL FINDINGS
We undertook a functional brain imaging (fMRI) experiment to investigate how both primary and second-order levels of physiological (viscerosensory) representation impact on the processing of external emotional cues. 12 participants were scanned while judging face stimuli during both exercise and non-exercise conditions in the context of true and false auditory feedback of tonic heart rate. We observed that the perceived emotional intensity/salience of neutral faces was enhanced by false feedback of increased heart rate. Regional changes in neural activity corresponding to this behavioural interaction were observed within included right anterior insula, bilateral mid insula, and amygdala. In addition, right anterior insula activity was enhanced during by asynchronous relative to synchronous cardiac feedback even with no change in perceived or actual heart rate suggesting this region serves as a comparator to detect physiological mismatches. Finally, BOLD activity within right anterior insula and amygdala predicted the corresponding changes in perceived intensity ratings at both a group and an individual level.
CONCLUSIONS/SIGNIFICANCE
Our findings identify the neural substrates supporting behavioural effects of false physiological feedback, and highlight mechanisms that underlie subjective anxiety states, including the importance of the right anterior insula in guiding second-order "cognitive" representations of bodily arousal state
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