Short communication: detection and molecular characterization of hepatitis E virus in domestic animals of São Tomé and Príncipe     

Mesquita  João Rodrigo  Istrate  Claudia  Santos-Ferreira  Nânci L.  Ferreira  Ana S.  Abreu-Silva  Joana  Veiga  José  van der Poel  Wim H. M.  Nascimento  Maria S. J. 《Tropical animal health and production》2019,51(2):481-485

Tropical Animal Health and Production - As in most of the African continent, the status of hepatitis E virus (HEV) infection in domestic animals in São Tomé and Príncipe, an...  相似文献   

Serological evaluation of precolostral serum samples to detect Bovine viral diarrhea virus infections in large commercial dairy herds     

Jeremy Schefers  Claudia Munoz-Zanzi  James E Collins  Sagar M Goyal  Trevor R Ames 《Journal of veterinary diagnostic investigation》2008,20(5):625-628

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RABBIT HEMORRHAGIC DISEASE VIRUSES DETECTED IN PET RABBITS IN A COMMERCIAL LABORATORY IN EUROPE     

Rachel E. Marschang  Karola Weider  Hanna Erhard  Eva-Maria Klas  Claudia Laik-Schandelmaier 《Journal of Exotic Pet Medicine》2018,27(4):27-30

Rabbit hemorrhagic disease (RHD) is an important cause of disease and mortality in wild and domestic European rabbits (Oryctolagus cuniculus) throughout the world. Testing for 2 distinct RHD virus types (RHDV/RHDVa and RHDV2) was carried out on samples collected from 684 rabbits submitted from veterinary practices and private owners throughout Europe between January 2015 and June 2017. Four (0.6%) were positive for RHDV/RHDVa and 257 (37.4%) were positive for RHDV2. RHDV/RHDVa was detected in individual samples from Germany and the Netherlands, while RHDV2 was found in animals from Germany, Great Britain, Luxembourg, The Netherlands, Spain, Switzerland, Poland, Belgium, Austria, Sweden, and Finland.  相似文献   

In vivo long-term effects of retinoic acid exposure in utero on induced hyperplastic epidermal foci in murine skin     

García-Fernández RA  Pérez-Martínez C  Espinosa-Alvarez J  García-Iglesias MJ 《Veterinary dermatology》2007,18(5):287-293

Adult Naval Medical Research Institute (NMRI) mice, after prenatal exposure to retinoic acid (RA), were treated with a standard two-stage skin carcinogenesis regime to characterize hyperplastic epidermal foci that precede the appearance of cutaneous papillomas, and to investigate the in vivo long-term action of RA on adult mouse skin treated with DMBA (7,12 dimethyl benz[a]anthracene) and TPA (12-O-tetradecanoylphorbol 13-acetate). The results demonstrate that RA administered to pregnant mice had a long-term inhibitory action on the cell differentiation and development of hyperplastic lesions occurring prior to cancer on the adult skin of their offspring as well as a stimulatory effect on cell proliferation of these hyperplastic lesions.  相似文献   

Spongiform neurodegenerative disease in a Persian kitten   总被引：1，自引：0，他引：1  

Salvadori C  Lossi L  Arispici M  Cantile C 《Journal of Feline Medicine and Surgery》2007,9(3):242-245

A congenital encephalopathy with spongiform degeneration and prominent neuronal apoptosis was observed in a 4-month-old Persian male cat with a history of depressed mental status and ataxia. On clinical examination, signs included right head tilt, ventroflexion of the head and neck, and tetraparesis. Histological examination of the central nervous system revealed multifocal, bilateral and symmetrical vacuolar degeneration of the neuropil, mainly involving the cerebellar and vestibular nuclei area, the caudal colliculi, the mesencephalic nuclei, the tegmental area and the deeper layer of the cerebral cortex. Accumulation of phosphorylated neurofilaments was detected in neuronal perikarya of the deep cortical layers, hippocampus and thalamus. Numerous pyknotic and apoptotic neurons were also observed in the cerebral cortex. These neuropathological changes differ from those observed in previous reports of spongiform degeneration of the grey matter in cats and were suggestive of a congenital neurodegenerative disease.  相似文献   

Rapid sequence modification in the highly polymorphic region (HPR) of the hemagglutinin gene of the infectious salmon anaemia virus (ISAV) suggests intra-segmental template switching recombination     

Matías Cárdenas  Claudia Galleguillos  Karina Acevedo  Catarina Ananias  Javiera Alarcón  Sofía Michelson  Jorge Toledo  Margarita Montoya  Claudio Meneses  Eduardo Castro-Nallar  Yesseny Vásquez-Martínez  Marcelo Cortez-San Martin 《Journal of fish diseases》2020,43(12):1483-1496

The ISAV has a genome composed of eight segments of (–)ssRNA, segment 6 codes for the hemagglutinin–esterase protein, and has the most variable region of the genome, the highly polymorphic region (HPR), which is unique among orthomyxoviruses. The HPR has been associated with virulence, infectivity and pathogenicity. The full length of the HPR is called HPR0 and the strain with this HPR is avirulent, in contrast to strains with deleted HPR that are virulent to varying degrees. The molecular mechanism that gives rise to the different HPRs remains unclear. Here, we studied in vitro the evolution of reassortant recombinant ISAV (rISAV) in Atlantic salmon head kidney (ASK) cells. To this end, we rescued and cultivated a set of rISAV with different segment 6-HPR genotypes using a reverse genetics system and then sequencing HPR regions of the viruses. Our results show rapid multiple recombination events in ISAV, with sequence insertions and deletions in the HPR, indicating a dynamic process. Inserted sequences can be found in four segments of the ISAV genome (segments 1, 5, 6, and 8). The results suggest intra-segmental heterologous recombination, probably by class I and class II template switching, similar to the proposed segment 5 recombination mechanism.  相似文献   

Susceptibility of Caligus rogercresseyi collected from the native fish species Eleginops maclovinus (Cuvier) to antiparasitics applied by immersion     

Margarita P. Gonzlez Gmez  Loreto Ovalle  Mylena Menanteau  Claudia Spinetto  Renato Oyarzún  Mario Rivas  Cristian Oyarzo 《Journal of fish diseases》2019,42(8):1143-1149

A major challenge for Chilean salmon farming is infestation by the ectoparasite Caligus rogercresseyi. In addition, there is evidence that a loss of chemotherapeutic treatment efficacy against important fish pathogens is occurring in salmon farming, including antiparasitic efficacy. Currently, there are known techniques that allow the determination of the susceptibility profile of parasites to antiparasitic treatment. However, there is scarce information about both threshold values and categorization of antiparasitic susceptibility for C. rogercresseyi. Bioassay technique allowed the determination of both mean values and the natural variation of EC50%, which were contrasted with available susceptibility thresholds. Results allowed to determine that parasites from the native fish host, Eleginops maclovinus, are susceptible to azamethiphos, deltamethrin and cypermethrin treatments, showing a high susceptibility profile to antiparasitics.  相似文献   

Effects of commercial thinning,log position in the stem,and cutting width on the surface quality of cants produced by a chipper-canter     

Claudia B. Cáceres  Svetka Kuljich  Ahmed Koubaa 《Wood material science & engineering》2018,13(1):28-35

Fifteen stems of jack pine (Pinus banksiana Lamb.) of 3 commercial thinned plots (control, moderate, and intensive thinning) and 15 stems of black spruce (Picea mariana (Mill.) B.S.P), both coming from the Abitibi-Témiscamingue region – Canada, were cross-cut into three 2.4?m length sections: bottom, middle, and top logs. Logs were processed with a chipper-canter at three cutting widths (12.7, 19.1, and 25.4?mm), producing chips and a three-faced cant. The middle section of the cant was used to evaluate surface quality across the grain on each face. Roughness and waviness parameters and depth of torn grain were recorded. Knot characteristics were assessed in the three cant faces. Poorer surface quality was found in the lower part compared to the upper part of the cant for both species. At larger cutting widths, jack pine logs coming from a natural stand showed lower surface quality compared to logs from thinned stands. Black spruce waviness increased with the cutting width and stem height. These results were attributed to the increase of forces and vibration when cutting at larger cutting widths, which was worsened by the presence of bigger, more numerous knots at the control plot and in the top logs. Black spruce had deeper torn grain compared to jack pine. Their differences in knot characteristics resulted in a maximum torn grain depth favored by the presence of more knots rather than by bigger knot size. Other knot characteristics, such as the position of the knots in the cant face, the insertion angle of the branch and the distribution of the knots around the log, should be studied to better understand the relationship between torn grain formation and knottiness.  相似文献   

Shrinkage variation in Japanese larch (Larix kaempferi, [Lamb.]Carr.) progenies/provenances trials in Eastern Canada     

Claudia B. Cáceres  Yves Fortin 《Wood material science & engineering》2018,13(2):97-103

Twelve-year-old Japanese larch (Larix kaempferi [Lamb.]Carr.) trees of 20 different progenies and/or provenances were sampled at one site in the Mauricie region of Quebec. Two standard samples were obtained at breast height and closer to the bark from each tree. Partial and total radial, tangential, and volumetric shrinkages, and tangential/radial (T/R) shrinkage ratios were assessed. All of these variables were significantly affected by the progeny/provenance. Drying defects are one of the main reasons for downgrading larch lumber; thus, T/R shrinkage ratio was considered for the selection of progenies/provenances for lumber production purposes. Lowest partial and total T/R shrinkage ratios were obtained with progenies/provenances 8964, 8904, 8962, 8957, 8907, 8927, 7283, and 7795. Among them, lowest partial and total tangential, radial, and volumetric shrinkages were found in progenies/provenances 8964, 8962, and 8907 as well. Other physico-chemical (mechanical properties, density, extractive content) and silvicultural (growth rate) attributes should also be taken into consideration for an adequate selection of progenies/provenances according to the specific final utilization.  相似文献   

Overall development of a bioprocess for the outdoor production of Nannochloropsis gaditana for aquaculture          下载免费PDF全文

Karina Riveros  Claudia Sepulveda  Jazmín Bazaes  Paola Marticorena  Carlos Riquelme  Gabriel Acién 《Aquaculture Research》2018,49(1):165-176

In this paper, a systematic methodology is shown for the scaling‐up of Nannochloropsis gaditana production for aquaculture uses. First, an adequate culture medium was developed, prepared using fertilizers instead of pure chemicals. Subsequently, the performance of N. gaditana was modelled as a function of average irradiance; this model being validated in continuous culture experiments. The model was used to determine the optimal dilution rate as well as the expected biomass concentration and productivity at optimal conditions. Finally, outdoor experiments were performed to confirm the model's validity and to determine optimal conditions at real production step. Biomass productivity values of up to 0.08 g L^?1 day^?1 were obtained at an optimal dilution rate of 0.25 per day in 0.2 m wide flat‐panel reactors using culture medium containing 0.4 g/L NO^?₃ and 0.034 g/L·PO₄^?3. Fish trials with Atlantic Salmon demonstrated that the inclusion of produced biomass into fed increase the final weight up to 5%, thus confirming the adequacy of the biomass produced for aquaculture uses. The growth model and the scaling‐up strategy proposed here are necessary to develop real industrial‐scale processes capable of supplying microalgal biomass to the aquaculture markets, which in turn require a guaranteed supply and quality of the raw materials provided.  相似文献