30 research outputs found

    Novel snake papillomavirus does not cluster with other non-mammalian papillomaviruses

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    Papillomaviruses (PVs) are associated with the development of neoplasias and have been found in several different species, most of them in humans and other mammals. We identified, cloned and sequenced PV DNA from pigmented papilloma-like lesions of a diamond python (Morelia spilota spilota). This represents the first complete PV genome discovered in a Squamata host (MsPV1). It consists of 7048 nt and contains the characteristic open reading (ORF) frames E6, E7, E1, E2, L1 and L2. The L1 ORF sequence showed the highest percentage of sequence identities to human PV5 (57.9%) and Caribbean manatee (Trichechus manatus) PV1 (55.4%), thus, establishing a new clade. According to phylogenetic analysis, the MsPV1 genome clusters with PVs of mammalian rather than sauropsid hosts

    A SAS-6-like protein suggests that the Toxoplasma conoid complex evolved from flagellar components

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    SAS-6 is required for centriole biogenesis in diverse eukaryotes. Here, we describe a novel family of SAS-6-like (SAS6L) proteins that share an N-terminal domain with SAS-6 but lack coiled-coil tails. SAS6L proteins are found in a subset of eukaryotes that contain SAS-6, including diverse protozoa and green algae. In the apicomplexan parasite Toxoplasma gondii, SAS-6 localizes to the centriole but SAS6L is found above the conoid, an enigmatic tubulin-containing structure found at the apex of a subset of alveolate organisms. Loss of SAS6L causes reduced fitness in Toxoplasma. The Trypanosoma brucei homolog of SAS6L localizes to the basal-plate region, the site in the axoneme where the central-pair microtubules are nucleated. When endogenous SAS6L is overexpressed in Toxoplasma tachyzoites or Trypanosoma trypomastigotes, it forms prominent filaments that extend through the cell cytoplasm, indicating that it retains a capacity to form higher-order structures despite lacking a coiled-coil domain. We conclude that although SAS6L proteins share a conserved domain with SAS-6, they are a functionally distinct family that predates the last common ancestor of eukaryotes. Moreover, the distinct localization of the SAS6L protein in Trypanosoma and Toxoplasma adds weight to the hypothesis that the conoid complex evolved from flagellar components

    Exploring sex differences: insights into gene expression, neuroanatomy, neurochemistry, cognition, and pathology

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    Increased knowledge about sex differences is important for development of individualized treatments against many diseases as well as understanding behavioral and pathological differences. This review summarizes sex chromosome effects on gene expression, epigenetics, and hormones in relation to the brain. We explore neuroanatomy, neurochemistry, cognition, and brain pathology aiming to explain the current state of the art. While some domains exhibit strong differences, others reveal subtle differences whose overall significance warrants clarification. We hope that the current review increases awareness and serves as a basis for the planning of future studies that consider both sexes equally regarding similarities and differences

    Migraine, inflammatory bowel disease and celiac disease: A Mendelian randomization study

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    Objective: To assess whether migraine may be genetically and/or causally associated with inflammatory bowel disease (IBD) or celiac disease. Background: Migraine has been linked to IBD and celiac disease in observational studies, but whether this link may be explained by a shared genetic basis or could be causal has not been established. The presence of a causal association could be clinically relevant, as treating one of these medical conditions might mitigate the symptoms of a causally linked condition. Methods: Linkage disequilibrium score regression and two-sample bidirectional Mendelian randomization analyses were performed using summary statistics from cohort-based genome-wide association studies of migraine (59,674 cases; 316,078 controls), IBD (25,042 cases; 34,915 controls) and celiac disease (11,812 or 4533 cases; 11,837 or 10,750 controls). Migraine with and without aura were analyzed separately, as were the two IBD subtypes Crohn's disease and ulcerative colitis. Positive control analyses and conventional Mendelian randomization sensitivity analyses were performed. Results: Migraine was not genetically correlated with IBD or celiac disease. No evidence was observed for IBD (odds ratio [OR] 1.00, 95% confidence interval [CI] 0.99-1.02, p = 0.703) or celiac disease (OR 1.00, 95% CI 0.99-1.02, p = 0.912) causing migraine or migraine causing either IBD (OR 1.08, 95% CI 0.96-1.22, p = 0.181) or celiac disease (OR 1.08, 95% CI 0.79-1.48, p = 0.614) when all participants with migraine were analyzed jointly. There was some indication of a causal association between celiac disease and migraine with aura (OR 1.04, 95% CI 1.00-1.08, p = 0.045), between celiac disease and migraine without aura (OR 0.95, 95% CI 0.92-0.99, p = 0.006), as well as between migraine without aura and ulcerative colitis (OR 1.15, 95% CI 1.02-1.29, p = 0.025). However, the results were not significant after multiple testing correction. Conclusions: We found no evidence of a shared genetic basis or of a causal association between migraine and either IBD or celiac disease, although we obtained some indications of causal associations with migraine subtypes. Keywords: Mendelian randomization; celiac disease; gastrointestinal disease; genetic correlation; inflammatory bowel disease; migraine

    Genome sequencing reveals metabolic and cellular interdependence in an amoeba-kinetoplastid symbiosis

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    Endosymbiotic relationships between eukaryotic and prokaryotic cells are common in nature. Endosymbioses between two eukaryotes are also known; cyanobacterium-derived plastids have spread horizontally when one eukaryote assimilated another. A unique instance of a non-photosynthetic, eukaryotic endosymbiont involves members of the genus Paramoeba, amoebozoans that infect marine animals such as farmed fish and sea urchins. Paramoeba species harbor endosymbionts belonging to the Kinetoplastea, a diverse group of flagellate protists including some that cause devastating diseases. To elucidate the nature of this eukaryote-eukaryote association, we sequenced the genomes and transcriptomes of Paramoeba pemaquidensis and its endosymbiont Perkinsela sp. The endosymbiont nuclear genome is ~9.5 Mbp in size, the smallest of a kinetoplastid thus far discovered. Genomic analyses show that Perkinsela sp. has lost the ability to make a flagellum but retains hallmark features of kinetoplastid biology, including polycistronic transcription, trans-splicing, and a glycosome-like organelle. Mosaic biochemical pathways suggest extensive ‘cross-talk’ between the two organisms, and electron microscopy shows that the endosymbiont ingests amoeba cytoplasm, a novel form of endosymbiont-host communication. Our data reveal the cell biological and biochemical basis of the obligate relationship between Perkinsela sp. and its amoeba host, and provide a foundation for understanding pathogenicity determinants in economically important Paramoeba

    The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

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    Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

    Comparison of three miniplate systems in experimentally induced ulnar and radial fractures in pigeons (Columba livia)

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    Although bone plates have advantages over other fixation methods for certain indications, they are still uncommonly used in avian fracture repair. One reason are the thin cortices of avian bones. They lead to a reduced screw holding power. Another reason was that until now there was no evaluated plating system appropriate and available for the use of fracture repair in smaller birds. Therefore a study with three different miniplate systems was carried out. Three groups (A, B and C) of six pigeons (Columba livia) each were used. The left ulna and radius of the pigeons were transected and the ulna was repaired with a bone plate. Three plate systems were used: in group A, a 1.3 adaption plate; in group B the same plate with washers to achieve a limited contact system; in group C a maxillofacial miniplate. Healing was evaluated with radiographs after two and four weeks, a flight test was performed after 4 weeks, and a necropsy of the wing was carried out. Group A achieved the best flight results (100% good). In group B no effect of the limited contact concept was visible at necropsy and a high percentage of screws loosened which led to repair failure (33%). The maxillofacial miniplates of group C were too weak and bent (100%). In conclusion only the adaption plate 1.3 met the requirements for avian osteosynthesis. To adapt the system better to the properties of avian bone, further trials using smaller drill bits or screws with a smaller thread pitch should be carried out. Obwohl Platten zur Fixation von Frakturen erhebliche Vorteile gegenüber anderen Systemen aufweisen, werden sie in der Vogelchirurgie nur selten verwendet. Verantwortlich dafür sind einerseits die dünnen Kortizes der Vogelknochen, andererseits die limitierte Verfügbarkeit geeigneter Platten. In der vorliegenden Studie wurden in drei Gruppen (A, B und C) mit je sechs Tauben drei Plattensysteme untersucht. Der linke Radius und die linke Ulna wurden intraoperativ durchtrennt und die Fraktur anschliessend mit einer Miniplatte fixiert. In der Gruppe A wurde eine 1.3 Adaptationsplatte, in Gruppe B dieselbe Platte mit Unterlegscheiben und in Gruppe C eine Maxillofazialplatte verwendet. Die Heilung wurde mittels Röntgenbilder nach zwei und nach vier Wochen evaluiert. Zusätzlich wurde nach vier Wochen ein Flugtest durchgeführt, die Tiere anschliessend euthanasiert und der Flügel seziert. Gruppe A erreichte die besten Flugergebnisse (100% gut). In Gruppe B konnte kein Effekt des „limitierten Kontakt Konzepts“ festgestellt werden und in 33% ist die Fraktur nicht abgeheilt aufgrund gelöster Schrauben. Die Maxillofazialplatten der Gruppe C waren zu weich und haben sich verbogen (100%). Fazit: Nur die 1.3 Adaptionsplatte scheint zur Osteosynthese bei Vögeln geeignet. Um das System besser an die Eigenschaften von Vogelknochen anzupassen, könnten in zukünftigen Studien kleinere Bohrer oder Schrauben mit einer geringeren Gewindesteigung eingesetzt werden

    It's a wart! A case report of papillomatosis in snakes and general considerations on the managemet of papillomatosis in reptiles

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    It was possible to demonstrate papillomavirus DNA with a broad range PCR from skin biopsies of a diamond python (Morelia spilota spilota) with nodulous skin alterations. Epidemiology and clinical manifestation of reptile papillomatosis are suspected to be similar to papillomas in mammals

    Volumetric Differences in Cerebellum and Brainstem in Patients with Migraine: A UK Biobank Study

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    Background: The cerebellum and the brainstem are two brain structures involved in pain processing and modulation that have also been associated with migraine pathophysiology. The aim of this study was to investigate possible associations between the morphology of the cerebellum and brainstem and migraine, focusing on gray matter differences in these brain areas. Methods: The analyses were based on data from 712 individuals with migraine and 45,681 healthy controls from the UK Biobank study. Generalized linear models were used to estimate the mean gray matter volumetric differences in the brainstem and the cerebellum. The models were adjusted for important biological covariates such as BMI, age, sex, total brain volume, diastolic blood pressure, alcohol intake frequency, current tobacco smoking, assessment center, material deprivation, ethnic background, and a wide variety of health conditions. Secondary analyses investigated volumetric correlation between cerebellar sub-regions. Results: We found larger gray matter volumes in the cerebellar sub-regions V (mean difference: 72 mm3, 95% CI [13, 132]), crus I (mean difference: 259 mm3, 95% CI [9, 510]), VIIIa (mean difference: 120 mm3, 95% CI [0.9, 238]), and X (mean difference: 14 mm3, 95% CI [1, 27]). Conclusions: Individuals with migraine show larger gray matter volumes in several cerebellar sub-regions than controls. These findings support the hypothesis that the cerebellum plays a role in the pathophysiology of migraine
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