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71.
The purpose of this study was to determine the clinical and laboratory profiles of canine leishmaniasis in two distinct areas. Dogs from urban and rural areas were examined. The population studied in the metropolitan area included 54 dogs. Of these, 20 (37%) animals did not present with any signs suggestive of visceral leishmaniasis (VL). Among these, only eight were confirmed negative by ELISA (rK39 and CE) and 12 dogs, clinically negative for leishmaniasis, were seropositive by ELISA (rK39 and CE). Thinness, conjunctivitis and onychogryphosis were the most frequent clinical signs in the urban areas, followed by crusty lesions, alopecia, ulcerated lesions, hyperkeratosis and exfoliation. In the metropolitan area human VL cases occurred mainly in 1991, 1992, 1999 and 2000. In the rural areas the ELISA rK39 test detected a seroprevalence of 11.3% and ELISA CE (Leishmania crude extract) of 20.6%. Thirty-nine dogs were examined 6 months after the first visit. Serological exams using rK39 antigen showed seroconversion of only one dog, whereas Leishmania CE showed seroconversion of 13 (33.4%) dogs. In this rural environment 83.3% of the positive dogs were asymptomatic. Lutzomyia intermedia and Lu. longipalpis were the most predominant sandfly vector species. Amastigotes were identified in spleen and liver fragments of symptomatic necropsied animals. PCR amplification of DNA isolated from promastigote culture indicated that the species was Leishmania chagasi. This finding suggests that delayed diagnosis and euthanasia of potentially infectious animals may occur with an increased transmission risk to sandflies and subsequently to humans.  相似文献   
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Control of canine visceral leishmaniasis (VL) remains a difficult and serious problem mostly because there is no reliable and effective vaccine available to prevent this disease. A mixture of three recombinant leishmanial antigens (TSA, LeIF and LmSTI1) encoded by three genes highly conserved in the Leishmania genus have been shown to induce excellent protection against infection in both murine and simian models of cutaneous leishmaniasis. A human clinical trial with these antigens is currently underway. Because of the high degree of conservation, these antigens might be useful vaccine candidates for VL as well. In the present study, using the dog model of the visceral disease, we evaluated the immunogenicity of these three antigens formulated with two different adjuvants, MPL-SE and AdjuPrime. The results were compared with a whole parasite vaccine formulated with BCG as the adjuvant. In order to investigate if sensitization with the recombinant antigens would result in recognition of the corresponding native parasite antigens upon infection, the animals were exposed for four weeks after the termination of the immunization protocol with the recombinant antigens to a low number of L. chagasi promastigotes, an etiological agent of VL. Immune response was evaluated by quantitative ELISA in the animal sera before and after exposure to the viable parasites. Both antigen specific IgG1 and IgG2 antibody levels were measured. Immunization of dogs with the recombinant antigens formulated in either MPL-SE or AdjuPrime resulted in high antibody levels particularly to LmSTI1. In addition, this immunization although to low levels, resulted in the development of antibody response to the whole parasite lysate. Importantly, experimental exposure with low numbers of culture forms of L. chagasi promastigotes caused a clear boost in the immune response to both the recombinant antigens and the corresponding native molecules. The boost response was predominantly of the IgG2 isotype in animals primed with the recombinant antigens plus MPL-SE. In contrast, animals primed with the recombinant antigens formulated in AdjuPrime as well as animals vaccinated with crude antigen preparation responded with mixed IgG1/IgG2 isotypes. These results point to the possible use of this antigen cocktail formulated with the adjuvant MPL-SE in efficacy field trials against canine VL.  相似文献   
74.
Badnavirus in Bougainvillea spectabilis showing virus-like symptoms was identified by the presence of bacilliform particles, measuring 125–130 × 30–40 nm in leaf-dip preparations and by analysis of its putative open reading frame 3 sequence. The virus, tentatively named Bougainvillea bacilliform virus (BBV), had the highest identities (up to 60%) with Spiraea yellow leaf spot virus, Gooseberry vein banding associated virus, Taro bacilliform virus, and Citrus yellow mosaic virus. In phylogenetic analysis, BBV clustered with Badnavirus putative species. Attempts to transmit the virus to several hosts failed. This is the first report of a new Badnavirus detected in Bougainvillea.  相似文献   
75.
A case of protothecosis is reported in an adult goat with inspiratory dyspnea and stertor. Dermatitis with prominent ulcerated nodules up to 3 cm in diameter was observed in the muzzle at the mucocutaneous junctions of nasal and lip skin, and in the border of the pinna. Histologic lesions were necrotizing pyogranulomatous dermatitis and rhinitis with myriads of walled sporangia, characteristic of Prototheca wickerhamii. This seems to be the first report of protothecosis in a goat.  相似文献   
76.
The impact of substituting forests for smallholder agricultural production systems on soil carbon (C) stocks is not well understood in Brazilian Amazonia. Most surveys of soil C stocks are restricted to the top 30 cm of soil and do not include measurements of litter and root stocks. Here, we quantify the stocks of C in soil (0–100 cm depth), aboveground litter and coarse roots of traditional (slash‐and‐burn) and alternative (Schizolobium amazonicum‐planted forest and silvopastoral system) smallholder agricultural systems, which were compared with a reference area (forest regrowth) in the eastern Amazonia. The soil C stocks in the 0–100 cm layer were larger in the forest regrowth treatment (156.8 ± 15.5 Mg/ha) than in the other treatments (S. amazonicum = 85.3 ± 6.5, silvopastoral = 108.0 ± 4.4 Mg/ha) but did not differ from the soil C stock in the slash‐and‐burn treatment (127.2 ± 6.1 Mg/ha). The soil C stocks at the 0–30 cm layer, which represented 33–50% of the total C of the 0–100 cm layer, did not differ among the treatments. The litter C stocks were ranked in the following order: silvopastoral > forest regrowth > S. amazonicum > slash‐and‐burn. The forest regrowth treatment had a greater coarse root C stock (0.84 ± 0.10 Mg/ha) than the other treatments (silvopastoral = 0.28 ± 0.03, S. amazonicum = 0.18 ± 0.03, slash‐and‐burn = 0.27 ± 0.04 Mg/ha). Soil, litter and root C stocks were negatively impacted by the conversion of forest regrowth to cultivation systems.  相似文献   
77.
Tribolium castaneum is a pest of stored foods that causes serious economic losses. Understanding insect nutritional requirements and the effects of different diets on insect development can provide tools for developing strategies to control insect and integrated pest management systems. In this work we studied the performance of the T. castaneum on different plant diets composed of Vigna unguiculata, Phaseolus vulgaris and wheat flours. The diets interfered differentially with development and insect survival. Larvae size was reduced about 60 % in larvae fed with V. unguiculata flour. A delay in pupae formation was also observed. The larval mortality of 100 % was observed in the P. vulgaris diet. Carbohydrate and triglyceride showed variations during development and with different diets. Larvae fed with wheat diets showed a high concentration of carbohydrates 21 days after hatching (DAH) and triglyceride at 15 and 21 DAH. Larvae fed with wheat diets showed α-amylase activity during development. At 15 DAH the activity of larvae fed with V. unguiculata increased about 50 %. Cysteine protease activity in larvae fed with wheat remained high throughout development. Serine protease activity also varied according to diets. These results show that the nutritional state of developing larvae varies greatly with respect to triglycerides, carbohydrate and digestive enzymes depending on the diet and larval stage. Altogether, these results show that changes in dietary nutrients can interfere with insect physiology. Therefore changes in diet composition that may deprive insects of essential nutrients or include toxic compounds might be a good control strategy for stored product pests.  相似文献   
78.
The purpose of this study was to determine the effect of enrofloxacin in the carrier stage of Haemophilus parasuis in naturally colonized weaned pigs. Twenty-three pigs colonized by H. parasuis received either 7.5 mg/kg body weight (BW) of enrofloxacin or a saline solution intramuscularly at weaning. Nasal and tonsillar swab samples were collected daily throughout the study and at necropsy and tested by quantitative polymerase chain reaction (qPCR). The H. parasuis isolates obtained from samples collected at necropsy were subjected to genotyping by enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) and a multiplex PCR for the detection of the virulence-associated trimeric autotransporter (vtaA) genes. Haemophilus parasuis was detected in the nasal cavity and tonsils of pigs in the control group throughout the study. Antibiotic-treated pigs tested negative for H. parasuis at 1 d post-treatment and the proportion of nasal samples that tested positive was higher for control pigs than for treated pigs at 1, 2, 3, 4, 5, 6, and 7 d post-treatment and at 2, 4, and 5 d post-treatment for tonsil samples (P < 0.003). Genotyping by ERIC-PCR demonstrated that pigs were colonized with a common H. parasuis strain at the end of the study. Isolates were negative for the vtaA gene, which indicates the absence of vtaA virulence factor. In conclusion, enrofloxacin significantly reduced the H. parasuis load in naturally colonized pigs, but was unable to completely eliminate the organism.  相似文献   
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80.
Little is known about the neural mechanisms controlling head posture and why they fail in clinical syndromes like torticollis. It is well established, however, that the brain controls eye position by integrating eye velocity commands. By electrically stimulating and reversibly inactivating midbrain sites in the head-free (nonimmobilized) monkey, we found that the interstitial nucleus of Cajal functions as a neural integrator for head posture. We suggest that a bilateral imbalance in this structure, through either direct damage or inappropriate input, could be one of the mechanisms underlying torticollis.  相似文献   
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