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When first described in 1946, bovine viral diarrhea (BVD) was characterized as an acute transmissible disease associated with severe leucopenia, high fever, depression, diarrhea, gastrointestinal erosions, and hemorrhages. Recently the severe acute form has been related only to some hypervirulent BVDV-2 strains. This article reports the detection of BVDV-1b associated with an acute and fatal outbreak of BVD in a Brazilian beef cattle herd. Depression, anorexia, watery diarrhea, sialorrhea, and weakness were observed in six steers. One of these animals was evaluated for laboratorial, clinical, and pathological alterations. Laboratory findings were non-specific; clinically, the animal was weak, with dehydration and erosive oral lesions. Pathological alterations were predominant at the tongue, esophagus, and rumen. A RT-PCR assay using primers to partially amplify the 5′ untranslated region (5′UTR) of the BVDV genome was performed and identified BVDV in all clinical samples analyzed. Phylogenetic analysis of BVDV derived from lymph node revealed that this strain was clustered within the BVDV subtype 1b. This differentiating was only possible to be performed by molecular characterization since both clinical presentation and pathologic findings were similar to BVDV-2 infection.  相似文献   
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Anaplasma marginale is an obligate intraerythrocytic rickettsial pathogen (order, Rickettsiales: family, Anaplasmataceae) that causes bovine anaplasmosis. This disease is widely distributed in tropical and sub‐tropical regions of the world and causes important economic losses to cattle production. Major surface protein (MSP)1a (msp1α gene) is one of the six MSPs identified on A. marginale from cattle, whose sequence and size vary according to the number of tandem 28‐ to 29‐amino acid repeats. This study characterized the msp1α and msp4 genes obtained from three distinct Brazilian herds from the State of Paraná. Three strains of the msp1α and one strain of the msp4 gene were sequenced. The strains evaluated revealed PCR products of different size, representing three, five and six internal repeats. Sequence analyses confirmed the number of tandem sequence copies and revealed a high degree of sequence identity with strains from other Brazilian States, as well as strains from the USA, Europe and Israel. The msp1α DNA and amino acid sequences from A. marginale and DNA sequences of msp4 strains did not reveal distinct phylogeographical segregation. However, the amino acid sequences of msp4 demonstrated definite phylogeographical relationship. These results suggest that the amino acid sequences of msp4 should be used for phylogenetic identification of A. marginale strains and may be an important tool for the epidemiology and control of anaplasmosis. Additionally, the close similarity of the Paraná strains of A. marginale with strains from USA, Europe and Asia may reflect the introduction of these genes during the development of the Brazilian bovine herd.  相似文献   
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The susceptibility of cattle and buffalos to chronic copper poisoning (CCP) was compared by using cattle (n = 10) and buffalo (n = 10) steers distributed into two copper supplemented (n = 6) and two control (n = 4) groups. Supplemented animals received 2 mg copper (Cu)/kg body weight daily for one week, with an additional 2 mg weekly until the end of the experiment (day 105). Three liver biopsies (day 0, 45, and 105) were obtained for mineral analyses; clinical examinations and blood samples were obtained every 15 days. Three supplemented cattle and two buffalos with typical manifestations of CCP died. There were no differences in the frequency of mortality between cattle and buffalos; hepatic copper concentration was higher in cattle than buffalos. These findings suggest that buffalos and cattle might be equally susceptible to CCP. However, buffalos accumulate less liver copper than cattle and have a lower threshold of hepatic Cu accumulation, which leads to clinical manifestation of CCP.  相似文献   
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Even though there have been many actions to limit chlorinated hydrocarbons used to control insects, many significant environmental problems connected with agricultural pest control remain. To deal with environmental effects in pest control strategy requires economic evaluation even though there are analytical difficulties. Environmental effects of pest control methods can be given economic meaning through the use of implied values measured in terms of sacrifices of conventional benefits. Where the biological significance of damages from pest control methods is known, the problem is to evaluate the differences in net benefits for alternative strategies. However, for those damages which involve uncertainty some sort of hazard-benefit analysis is needed with the ultimate decision made by persons responsible to society for value judgements. More co-operation is needed by economists and pest control experts to provide the best information possible within the limits of their professional expertise including analyzing pest control methods in the time dimension. High quality scientific analysis reduces the uncertainty for political decisions.  相似文献   
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Balantidium coli is a ciliated protozoan that inhabits the large intestine of swine, man, rodents, and nonhuman primates. Frequently this organism is associated with enteric diseases in man and nonhuman primates, with rare manifestations of disease in swine and other mammalian species. This report describes a case of B. coli-induced enteric disease in a 15-yr-old, mare, Finnish Horse after an acute onset of colic. Severe hemorrhagic and eosinophilic colitis with intense infiltration of intralesional B. coli-like ciliated protozoan were found histologically.  相似文献   
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