Hemorrhagic disease in dogs infected with an unclassified intraendothelial piroplasm in southern Brazil     

Loretti AP  Barros SS 《Veterinary parasitology》2005,134(3-4):193-213

A hemorrhagic disease affecting dogs in Brazil, referred to popularly as "nambiuvú" (bloody ears) and believed to be transmitted by ticks, has been observed in animals infected with an organism described originally in 1910 as a piroplasm, and known locally as Rangelia vitalli. In this series of 10 cases, the disease was characterized by anaemia, jaundice, fever, spleno- and lymphadenomegaly, hemorrhage in the gastrointestinal tract, and persistent bleeding from the nose, oral cavity and tips, margins and outer surface of the pinnae. The ixodid ticks Rhipicephalus sanguineus and Amblyomma aureolatum infested affected dogs from suburban and rural areas, respectively. Laboratory findings included regenerative anaemia, spherocytosis, icteric plasma and bilirubinuria. Those intracellular organisms were found in bone marrow smears but not in blood smears. Microscopically, zoites were seen within the cytoplasm of blood capillary endothelial cells. Parasitized and non-parasitized endothelial cells were positive immunohistochemically for von Willebrand factor (vWF). Langhans-type multinucleate giant cells were observed in the lymph nodes and choroid plexus. There was prominent erythrophagocytosis by macrophages in the lymph node sinuses and infiltration of the medullary cords by numerous plasma cells. Ultrastructurally, this organism had an apical complex that included a polar ring and rhoptries but no conoid. This parasite was contained within a parasitophorous vacuole that had a trilaminar membrane with villar protrusions and was situated in the cytoplasm of capillary endothelial cells. This organism tested positive by immunohistochemistry for Babesia microti. This pathogen was also positive by in situ hybridization for B. microti. Tentative clinical diagnosis in these cases was based on the history, clinical picture, haemogram and favorable response to therapy, and confirmed through microscopic examination of smears from the bone marrow or histological sections of multiple tissues, especially lymph nodes where zoites were most frequently found. The disease was reproduced by intravenous inoculation of blood from a naturally infected dog into an experimental dog. The authors demonstrate in this study that this organism is a protozoa of the phylum Apicomplexa, order Piroplasmorida. This piroplasm seems to be different from Babesia since it has an intraendothelial stage. Molecular phylogenetic analysis is necessary to better characterize this parasite and clarify its taxonomic status.  相似文献   

Leukocyte-hepatocyte interaction in calicivirus infection: differences between rabbits that are resistant or susceptible to rabbit haemorrhagic disease (RHD)     

Ferreira PG  Costa-E-Silva A  Oliveira MJ  Monteiro E  Aguas AP 《Veterinary immunology and immunopathology》2005,103(3-4):217-221

Calicivirus infection is lethal for adult rabbits, whereas young rabbits (less than 8-weeks-old) are resistant to the same infectious agent. The virus replicates in the liver and causes a fulminant hepatitis in adult rabbits leading to rabbit haemorrhagic disease (RHD); this is in contrast with the mild and transient hepatitis observed in infected young rabbits. We have used electron microscopy to compare liver leukocyte infiltrates between young (resistant) and adult (susceptible) rabbits, 36-48 h after inoculation of the animals with caliciviruses. In adult rabbits, liver infiltrates were made up mostly of heterophils, and they were located near hepatocytes showing severe cellular damage. In contrast, liver leukocyte infiltrates of RHD-resistant young rabbits were dominated by lymphocytes that depicted membrane contacts with the cell surface of undamaged hepatocytes. We conclude that: (i) the cellular inflammatory response of the liver to calicivirus infection is different in rabbits that are susceptible (adult) or resistant (young) to RHD; (ii) leukocyte infiltration of the adult liver by heterophils is probably directed at the removal of dead hepatocytes, whereas the liver lymphocytic infiltration of young rabbits suggests the expression of viral antigens on the surface of liver cells of the RHD-resistant animals.  相似文献   

To Users of the Hunter Color and Color Difference Meter     

Sidwell AP 《Science (New York, N.Y.)》1955,121(3151):736

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New Method of Presentation of Food Samples to the Hunter Color and Color Difference Meter     

Sidwell AP  Cain RF 《Science (New York, N.Y.)》1954,120(3121):666-667

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Schistosoma mansoni: development of challenge infections in mice exposed to irradiated cercariae     

SZUMLEWICZ AP  OLIVIER LJ 《Science (New York, N.Y.)》1963,140(3565):411-412

The principal effect of x-irradiated Schistosoma mansoni cercariae may be to slow the migration and development of the worms of a challenge infection. This would account for the smaller number of worms found in the portal system in the early weeks and the delayed accumulation of recoverable worms and eggs.  相似文献   

Changeover from Large to Small Animal Practice          下载免费PDF全文

Christie AP 《The Canadian veterinary journal. La revue veterinaire canadienne》1960,1(6):251-255

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番荔枝类果树（续）     

Geor.  AP 彭松兴 《热带作物科技》1991,(1):66-69

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评“情报化社会”理论     

董建华 《技术与市场》1984,(1)

产生背景“情报化社会”一词和D·贝尔等人首先提出的“后工业社会”是同义词。与这一词相接近的还有A·托夫勒的“第三次浪潮”,P·达林多夫的“后资本主义”社会等各种关于世界未来发展模式的理论。有人也把“情报化社会”译为“信息时代”。本文根据该理论提出者的本意给“情报”概念赋予最广泛的含义,而不局限于情报科学中“情报”一词所指的范畴。“情报化社会”理论是未来研究发展到六十年代末七十年代初的产物。1973年,由纽  相似文献   

Alterations in thyroid hormone concentrations in healthy sled dogs before and after athletic conditioning     

Evason MD  Carr AP  Taylor SM  Waldner CL 《American journal of veterinary research》2004,65(3):333-337

OBJECTIVE: To determine effects of athletic conditioning on thyroid hormone concentrations in a population of healthy sled dogs. ANIMALS: 19 healthy adult sled dogs. PROCEDURE: Serum concentrations of thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), free T4 (fT4), free T3 (fT3), and autoantibodies directed against T3, T4, and thyroglobulin were measured in sled dogs that were not in training (ie, nonracing season) and again after dogs had been training at maximum athletic potential for 4 months. RESULTS: Analysis revealed significant decreases in T4 and fT4 concentrations and a significant increase in TSH concentration for dogs in the peak training state, compared with concentrations for dogs in the untrained state. Serum concentrations of T4 and fT4 were less than established reference ranges during the peak training state for 11 of 19 and 8 of 19 dogs, respectively; fT4 concentration was greater than the established reference range in 9 of 19 dogs in the untrained state. CONCLUSIONS AND CLINICAL RELEVANCE: Decreased total T4 and fT4 concentrations and increased serum concentrations of TSH were consistently measured during the peak training state in healthy sled dogs, compared with concentrations determined during the untrained state. Although thyroid hormone concentrations remained within the established reference ranges in many of the dogs, values that were outside the reference range in some dogs could potentially lead to an incorrect assessment of thyroid status. Endurance training has a profound impact on the thyroid hormone concentrations of competitive sled dogs.  相似文献   

Theriogenology question of the month. Acute peritonitis secondary to intra-abdominal semen deposition     

Slater LA  Davidson AP  Dahlinger J 《Journal of the American Veterinary Medical Association》2004,225(10):1535-1537

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