Pathogenicity determinants in smut fungi revealed by genome comparison     

Schirawski J  Mannhaupt G  Münch K  Brefort T  Schipper K  Doehlemann G  Di Stasio M  Rössel N  Mendoza-Mendoza A  Pester D  Müller O  Winterberg B  Meyer E  Ghareeb H  Wollenberg T  Münsterkötter M  Wong P  Walter M  Stukenbrock E  Güldener U  Kahmann R 《Science (New York, N.Y.)》2010,330(6010):1546-1548

Biotrophic pathogens, such as the related maize pathogenic fungi Ustilago maydis and Sporisorium reilianum, establish an intimate relationship with their hosts by secreting protein effectors. Because secreted effectors interacting with plant proteins should rapidly evolve, we identified variable genomic regions by sequencing the genome of S. reilianum and comparing it with the U. maydis genome. We detected 43 regions of low sequence conservation in otherwise well-conserved syntenic genomes. These regions primarily encode secreted effectors and include previously identified virulence clusters. By deletion analysis in U. maydis, we demonstrate a role in virulence for four previously unknown diversity regions. This highlights the power of comparative genomics of closely related species for identification of virulence determinants.  相似文献   

Spin transfer torques in MnSi at ultralow current densities     

Jonietz F  Mühlbauer S  Pfleiderer C  Neubauer A  Münzer W  Bauer A  Adams T  Georgii R  Böni P  Duine RA  Everschor K  Garst M  Rosch A 《Science (New York, N.Y.)》2010,330(6011):1648-1651

Spin manipulation using electric currents is one of the most promising directions in the field of spintronics. We used neutron scattering to observe the influence of an electric current on the magnetic structure in a bulk material. In the skyrmion lattice of manganese silicon, where the spins form a lattice of magnetic vortices similar to the vortex lattice in type II superconductors, we observe the rotation of the diffraction pattern in response to currents that are over five orders of magnitude smaller than those typically applied in experimental studies on current-driven magnetization dynamics in nanostructures. We attribute our observations to an extremely efficient coupling of inhomogeneous spin currents to topologically stable knots in spin structures.  相似文献   

Tachypnea and Antipyresis in Febrile Horses after Sedation with α2‐Agonists     

A. Kendall  C. Mosley  J. Bröjer 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2010,24(4):1008-1011

Background: Signs of tachypnea after sedation of febrile horses with α₂‐agonists have been noted previously but have not been further investigated. Objectives: To examine the effects of xylazine and detomidine on respiratory rate and rectal temperature in febrile horses and to investigate if either drug would be less likely than the other to cause changes in these variables. Animals: Nine febrile horses and 9 healthy horses were included in the study. Methods: Horses were randomly assigned to sedation with xylazine 0.5 mg/kg or detomidine 0.01 mg/kg. Heart rate and respiratory rate were recorded before sedation and at 1, 3, and 5 minutes after injection. Hourly measurements of rectal temperature were performed starting before sedation. Results: All febrile horses experienced an episode of tachypnea and antipyresis after sedation. Rectal temperature in the febrile group was significantly lower at 1, 2, and 3 hours after sedation. In several measurements, the decrease was >1°C. Respiratory rate in the febrile group was significantly increased after sedation. All febrile horses were breathing >40 breaths/min and 3 horses >100 breaths/min 5 minutes after sedation. No differences were noted between the 2 treatments. No significant changes in respiratory rate or temperature were noted in the reference group. Conclusions and Clinical Importance: Febrile horses can become tachypneic after sedation with detomidine or xylazine. The antipyretic properties of α₂‐agonists need consideration when evaluating patients that have been sedated several hours before examination.  相似文献   

Effects of toxic and non‐toxic blue mussel meal on health and product quality of laying hens     

L. Jönsson  L. Holm 《Journal of animal physiology and animal nutrition》2010,94(3):405-412

Blue mussels (Mytilus edulis) are a potential protein source in poultry feeds because of their high methionine and cystein content. However, mussels may temporarily be contaminated with the toxin, okadaic acid. The aim of this small scale study was to evaluate the effects on animal health and morphology of the digestive tract of laying hens fed three different diets; a commercial feed and diets containing 15% normal or 15% toxic mussel meal, i.e. a concentration of 198.6 μg toxin per kg feed. Twelve laying hens were divided into six groups and fed the experimental diets for 8 weeks. Animal health, production performance and egg quality were recorded. At sacrifice, tissue samples were prepared for histological evaluation using light microscopy. Okadaic acid did not have any adverse effects on animal health or production parameters and no histological changes indicating disturbances in the digestive tract was observed. Internal egg quality was improved as eggs from hens fed either of the two mussel meal diets had an increased yolk colour. These results show that mussel meal functions as a novel protein source for laying hens and those toxic mussels at this level may be included in the feed without negative effects on parameters evaluated in this study.  相似文献   

Comparisons of 3‐, 2‐Dimensional,and M‐Mode Echocardiographical Methods for Estimation of Left Chamber Volumes in Dogs with and without Acquired Heart Disease     

A. Tidholm  A.B. Westling  K. Höglund  I. Ljungvall  J. Häggström 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2010,24(6):1414-1420

Background: Real‐time 3‐dimensional echocardiography (RT3D) is a recent technique based on volumetric scanning, eliminating the need for geometric modeling of the cardiac chambers and minimizing the errors caused by foreshortened views. Hypothesis: Estimations of left ventricular (LV) end‐diastolic (EDV) and end‐systolic volume (ESV), and left atrial (LA) size, differ depending on the echocardiographic technique of estimation. Animals: Fifty‐one dogs with acquired heart disease and 34 healthy control dogs. Methods: Prospective observational study by M‐mode (Teichholz method), Simpson's modified 2‐dimensional (2D) method, and RT3D methods for estimation of LV volumes. LA size was evaluated by 2D and RT3D methods. Results: RT3D showed good agreement with 2D for EDV and ESV, whereas Teichholz method overestimated LV volumes in comparison with the other 2 methods by approximately a factor 2. There were no statistically significant differences among the 3 methods in estimating ejection fraction. Comparison between RT3D assessment of LA end‐systolic volume per kilogram (LAs/kg) and LA to aortic ratio (LA/Ao) measured by 2D relative to each other showed that the RT3D method underestimated LAs/kg at lower values, and overestimated it at higher values. The difference between methods increased with increasing LA size. Conclusions and Clinical Importance: There was good agreement between RT3D and 2D methods of estimating EDV and ESV, whereas the Teichholz method overestimated LV volumes by approximately a factor 2. In comparison with RT3D, LA/Ao underestimated LA size, especially when LA was enlarged.  相似文献   

Alopecia areata in Eringer cows     

Katrin Timm  Silvia Rüfenacht  Claudia Von Tscharner  Valérie F. Bornand  Marcus G. Doherr  Anna Oevermann  Christine Flury  Stefan Rieder  Gaby Hirsbrunner  Cord Drögemüller  Petra J. Roosje 《Veterinary dermatology》2010,21(6):545-553

Alopecia areata is a hair loss disorder in humans, dogs and horses with a suspected autoimmune aetiology targeting anagen hair follicles. Alopecia areata is only sporadically reported in cows. Recently, we observed several cases of suspected alopecia areata in Eringer cows. The aim of this study was to confirm the presumptive diagnosis of alopecia areata and to define the clinical phenotype and histopathological patterns, including characterization of the infiltrating inflammatory cells. Twenty Eringer cows with alopecia and 11 Eringer cows without skin problems were included in this study. Affected cows had either generalized or multifocal alopecia or hypotrichosis. The tail, forehead and distal extremities were usually spared. Punch biopsies were obtained from the centre and margin of alopecic lesions and normal haired skin. Histological examination revealed several alterations in anagen hair bulbs. These included peri‐ and intrabulbar lymphocytic infiltration, peribulbar fibrosis, degenerate matrix cells with clumped melanosomes and pigmentary incontinence. Mild lymphocytic infiltrative mural folliculitis was seen in the inferior segment and isthmus of the hair follicles. Hair shafts were often unpigmented and dysplastic. The large majority of infiltrating lymphocytes were CD3⁺ T cells, whereas only occasional CD20⁺ lymphocytes were present in the peribulbar infiltrate. Our findings confirm the diagnosis of T‐cell‐mediated alopecia areata in these cows. Alopecia areata appears to occur with increased frequency in the Eringer breed, but distinct predisposing factors could not be identified.  相似文献   

Penile and preputial tumours in the horse: literature review and proposal of a standardised approach     

Van Den Top JG  Ensink JM  Gröne A  Klein WR  Barneveld A  Van Weeren PR 《Equine veterinary journal》2010,42(8):746-757

Penile and preputial tumours are not uncommon in the horse, but can cause discomfort and lead to serious complications. Several types of tumour of the male external genitalia have been described. The most common type is the squamous cell carcinoma (SCC), which is found mainly in older horses. Reports of a breed predilection for penile tumour formation are equivocal, but castration, coat colour, poor hygiene and various infectious agents have all been suggested to predispose to the development of some types of tumour (e.g. SCC, papilloma and melanoma). Careful assessment of the primary tumour is an important first step in the design of an optimal treatment protocol. Invasiveness, differentiation grade, tumour size and presence of metastases are all relevant to the decision to pursue additional diagnostic procedures or specific treatment options. To date, no standard protocol has been reported for the approach to penile tumours in the horse and treatments range from minimally invasive therapies (e.g. topical use of 5-fluorouracil) to radical surgical interventions (e.g. en bloc penile and preputial resection with penile retroversion). Completeness of removal of the neoplasm and therefore risk of recurrence is highly dependent on the type of therapy chosen. However, the size and histopathological features of the primary tumour are also important factors with respect to the likelihood of recurrence. This review describes the most common penile and preputial neoplasms in the horse, and outlines a standard protocol aimed at arriving at a specific diagnosis and tailoring the therapeutic approach accordingly.  相似文献   

Seroprevalence of Q fever (coxiellosis) in sheep from the Southern Marmara Region, Turkey     

Kennerman E  Rousset E  Gölcü E  Dufour P 《Comparative immunology, microbiology and infectious diseases》2010,33(1):37-45

Little information is available in Turkey on Q fever, a zoonose caused by Coxiella burnetii and transmitted from domestic ruminants. This study aimed at investigating the seroprevalence in sheep flocks from three provinces (Bursa, Balikesir and Canakkale). Serosurvey was undertaken on 42 flocks, which were categorised by sizes. Sera were collected randomly from specific age groups within the young population. CHEKIT Q-fever ELISA kit was used to identify the infection in sheep. The results showed that 20% (n=151) of sheep were seropositive. A total of 34 flocks (81%) revealed at least one seropositive animal. Higher seroprevalence was observed in Balikesir region. Larger flocks resulted more infected than medium and small flocks. An association was found between seropositivity and age, when the primiparous ewes (1-year old) had higher antibodies rates than newborn sheep (aged less than 10 months) or biparous ewes (2 years old). These results showed that Q fever infection was common and circulating in the studied region, hence encourage efforts to propose measures that could reduce the spread and the zoonotic risk.  相似文献   

Lineage relationship analysis of RORgammat+ innate lymphoid cells   总被引：1，自引：0，他引：1  

Sawa S  Cherrier M  Lochner M  Satoh-Takayama N  Fehling HJ  Langa F  Di Santo JP  Eberl G 《Science (New York, N.Y.)》2010,330(6004):665-669

Lymphoid tissue-inducer (LTi) cells initiate the development of lymphoid tissues through the activation of local stromal cells in a process similar to inflammation. LTi cells express the nuclear hormone receptor RORγt, which also directs the expression of the proinflammatory cytokine interleukin-17 in T cells. We show here that LTi cells are part of a larger family of proinflammatory RORγt(+) innate lymphoid cells (ILCs) that differentiate from distinct fetal liver RORγt(+) precursors. The fate of RORγt(+) ILCs is determined by mouse age, and after birth, favors the generation of cells involved in intestinal homeostasis and defense. Contrary to RORγt(+) T cells, however, RORγt(+) ILCs develop in the absence of microbiota. Our study indicates that RORγt(+) ILCs evolve to preempt intestinal colonization by microbial symbionts.  相似文献   

Particle acceleration on megaparsec scales in a merging galaxy cluster     

van Weeren RJ  Röttgering HJ  Brüggen M  Hoeft M 《Science (New York, N.Y.)》2010,330(6002):347-349

Galaxy clusters form through a sequence of mergers of smaller galaxy clusters and groups. Models of diffusive shock acceleration suggest that in shocks that occur during cluster mergers, particles are accelerated to relativistic energies, similar to conditions within supernova remnants. In the presence of magnetic fields, these particles emit synchrotron radiation and may form so-called radio relics. We detected a radio relic that displays highly aligned magnetic fields, a strong spectral index gradient, and a narrow relic width, giving a measure of the magnetic field in an unexplored site of the universe. Our observations show that diffusive shock acceleration also operates on scales much larger than in supernova remnants and that shocks in galaxy clusters are capable of producing extremely energetic cosmic rays.  相似文献