OBJECTIVE: To determine the prevalence of appendicular osteosarcoma (OSA) in Greyhounds compared with other breeds and identify potential intrinsic risk factors associated with development of OSA. DESIGN: Retrospective case series. ANIMALS: 179 dogs with primary appendicular OSA. PROCEDURES: Medical records of dogs in which primary appendicular OSA had been diagnosed between 1996 and 2005 were reviewed. Prevalence and crude odds ratios for OSA were calculated for various breeds by comparison with a reference population of mixed-breed dogs. Age and sex were examined as potential risk factors for the 3 breeds with highest prevalence. RESULTS: Breed period prevalence of OSA was highest for Greyhounds (21/339 [6.2%]), followed by Rottweilers (51/969 [5.3%]) and Great Danes (13/297 [4.4%]); all 21 Greyhounds with OSA were identified as having retired from racing. Sex was not identified as a risk factor for OSA in these breeds, but in all 3 breeds, risk of OSA increased with age. Greyhounds were significantly older at the time of OSA diagnosis (mean, 9.9 years) than were Rottweilers (8.3 years) and Great Danes (7.8 years). Rottweilers and Great Danes were more likely to have OSA involving the forelimbs than the hind limbs. The most frequent lesion sites for all 3 breeds were the proximal end of the humerus and distal end of the radius. The proximal end of the femur was also a common site for the Greyhounds. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the present study suggested that Greyhounds, Rottweilers, and Great Danes had an increased risk of developing OSA, compared with mixed-breed dogs. 相似文献
Nutrients constrain the soil carbon cycle in tropical forests, but we lack knowledge on how these constraints vary within the soil microbial community. Here, we used in situ fertilization in a montane tropical forest and in two lowland tropical forests on contrasting soil types to test the principal hypothesis that there are different nutrient constraints to different groups of microorganisms during the decomposition of cellulose. We also tested the hypotheses that decomposers shift from nitrogen to phosphorus constraints from montane to lowland forests, respectively, and are further constrained by potassium and sodium deficiency in the western Amazon. Cellulose and nutrients (nitrogen, phosphorus, potassium, sodium, and combined) were added to soils in situ, and microbial growth on cellulose (phospholipid fatty acids and ergosterol) and respiration were measured. Microbial growth on cellulose after single nutrient additions was highest following nitrogen addition for fungi, suggesting nitrogen as the primary limiting nutrient for cellulose decomposition. This was observed at all sites, with no clear shift in nutrient constraints to decomposition between lowland and montane sites. We also observed positive respiration and fungal growth responses to sodium and potassium addition at one of the lowland sites. However, when phosphorus was added, and especially when added in combination with other nutrients, bacterial growth was highest, suggesting that bacteria out-compete fungi for nitrogen where phosphorus is abundant. In summary, nitrogen constrains fungal growth and cellulose decomposition in both lowland and montane tropical forest soils, but additional nutrients may also be of critical importance in determining the balance between fungal and bacterial decomposition of cellulose. 相似文献
Formalin is used in shrimp industry to eliminate ectoparasites and as a disinfectant. However, the effect of formalin on shrimp's defense mechanism is unknown. Several biomarkers were used to assess the immune response of juveniles of the shrimp Litopenaeus schmitti exposed to different concentrations of formalin (10, 25 and 50 mg L?1) during 24 and 48 h. Formalin concentrations of 25 and 50 mg L?1 produced a significant reduction in the total haemocyte count at both 24 and 48 h. Peroxidase and phenoloxidase activity did not show variations. The total protein concentration in haemolymph of shrimps was not significantly different between experimental groups. Histological analysis showed hyperplasia in the gills of animals exposed at 10 mg L?1 for 24 h; however, the exposure at 25 and 50 mg L?1 caused necrosis in gills, hepathopancreas and the antennal gland. 相似文献
The pathogenicity of 10 bacterial isolates was investigated on potato, radish, carrot and beet, including sensitivity and pathogen control efficacy. The isolates were identified by morphological, biochemical and molecular methods. All isolates were pathogenic on radish, carrot, and beet, and were highly virulent on potato. Although the isolates were obtained from different locations in the El Fuerte Valley (Sinaloa, Mexico), they were similar in their morphological, physiological and biochemical characteristics. Sequences of the 16S rRNA gene obtained by PCR were identical for all isolates. These results indicate that the bacterial isolates from potato scabby tissue belong to S. acidiscabies. Furthermore, the effectiveness of fluazinam, both in vitro and under greenhouse and field conditions, represents a possibleoption for chemical control of potato common scab disease. While our results suggest that spraying at seeding is effective in controlling common scab, future studies to combine this treatment with seed dressing before planting will be conducted to determine if there is an increase in disease control. 相似文献
The objective of this research was to study the usefulness of nootkatone as a senescence indicator for Rouge La Toma cv. grapefruit (Citrus paradisi Macf.), simulating different treatments that included the normal postharvest handling of citrus fruits: temperature conditioning, cold storage, shipment periods to overseas markets such as Japan and the U.S., marketing conditions, and storage at nonchilling temperature (control treatments). The highest nootkatone levels, determined by GLC-MS analyses, were detected in fruits subjected to control treatments. No significant differences were observed in nootkatone levels between treatments either with or without temperature conditioning prior to the start of the cold storage. Levels of nootkatone increased throughout time for all assayed treatments. The linear regressions of nootkatone levels showed correlation coefficients of 0.80 and 0.83 with storage time (29 and 42 days, respectively). Therefore, nootkatone appears to be a good indicator of senescence for Rouge La Toma grapefruit. 相似文献
We carried out a cross-sectional study to investigate antimicrobial resistance patterns of Campylobacter coli isolated from Ontario grower-finisher pigs. From January to June 2004, 1200 samples were collected from 80 farms by obtaining a constant number (15) of fecal samples per farm. Susceptibility of the isolates to 11 antimicrobial drugs was determined by the agar-dilution technique. The overall prevalence of resistance to 1 or more antimicrobials among the isolates was 99.2%. High levels of resistance were observed for azithromycin, clindamycin, erythromycin, streptomycin, and tetracycline: 91.7%, 82.5%, 81.4%, 70.7%, and 63.7%, respectively. For sulfamethoxazole, ampicillin, and nalidixic acid, resistance was observed in 40.3%, 26.6%, and 22.7% of the isolates, respectively. Although at very low levels, resistance was observed for ciprofloxacin (a fluoroquinolone), chloramphenicol, and gentamicin: in 2.4%, 1.7%, and 0.2%, respectively. Many of the isolates (29.7%) were resistant to 5 antimicrobials, the most common being azithromycin, clindamycin, erythromycin, streptomycin, and tetracycline. Isolates from the same farm showed at least 5 patterns of resistance. Results from this study indicate high levels of resistance to the antimicrobial drugs most commonly used in the Canadian swine industry (macrolides, lincosamides, and tetracyclines) among C. coli isolated from grower-finisher pigs in Ontario. Macrolides and fluoroquinolones are the drugs most commonly used to treat severe human campylobacteriosis. Fortunately, at present, there is little resistance to fluoroquinolones among C. coli from pigs in Ontario. 相似文献
There is a growing interest in highly fermentable dietary fibers having the potential to reduce risks of disease through the production of short-chain fatty acids (SCFA). Recently a digestion-resistant retrograded maltodextrin (RRM), classified as type 3 resistant starch was developed. Systematic work to determine its molecular and physiological properties was carried out to determine (1) the fraction resistant to digestion in vitro and in vivo, (2) its postconsumption effect on blood glucose in healthy volunteers, and (3) its in vitro fermentation pattern, at different ages, by use of pooled fresh human fecal inoculum. RESULTS: The digestion resistant fraction obtained in vivo from ileostomy patients (59.4%) is similar to that obtained by the AOAC method for measuring retrograded resistant starch (59.7%). The relative glycemic response after consumption of 50 g of RRM was 58.5% compared to glucose set as 100%. When exposed to colonic microbiota, in vitro obtained indigestible fractions behave similarly to those obtained in vivo in ileostomy patients. Fermentation of RRM and production of butyric acid is negligible during the first months of life but develops subsequently during weaning. In adults, RRM fermentation results in a high yield of SCFA, with butyrate representing 21-31 mol % of total SCFA. The high yield of SCFA during colonic fermentation, observed from weaning age on, as well as the potential to help reduce glycemic load may be of benefit to a number of health-related functions in the host. Further study on clear clinical end points is warranted. 相似文献
The use of native and adapted forages is an alternative for sustainable production systems in northeast Brazil. The goal of this study was to evaluate the substitution of Tifton 85 by maniçoba hay on the performance and carcass traits of Morada Nova hair sheep. The 16 lambs that were used in this study initially weighed 19.36?±?1.48 kg, were housed in individual pens, and were slaughtered at 58 days of confinement. The dry matter intake (839.84 g/day and 3.81 % WB) was higher (P?<?0.05) in sheep fed maniçoba hay. The feed conversion was 7.39 for sheep fed maniçoba hay. The empty body weight (21.61 kg) and cold carcass weight (11.40 kg) did not differ (P?>?0.05) between sheep fed different hay types. The replacement of Tifton 85 by maniçoba hay did not influence the loin eye area (cm2) or carcass compactness index (kg/cm). The replacement of Tifton 85 by maniçoba hay in Morada Nova sheep diet did not affect the weight gain or carcass characteristics. The maniçoba hay can be considered a forage resource for feeding sheep in Brazilian semiarid tropics. 相似文献
The farmed red-bellied pacu Piaractus brachypomus is a valuative commercial fish widely exploited in fish farming. Histopathologic alterations in small intestine of this fish were associated with heavy roundworms infection. Of a total of thirty-five fish examined, all were parasitized with a prevalence of 100%, intensity of 290–6403, and mean intensity of infection of 4467.5 parasites per fish. According to the morphological features of whole nematodes examined using light and electronic microscopy, the parasite was identified as Rondonia rondoni Travassos. Rev Vet e Zoot 10, 59–70; 1920. The fish intestinal tissue alterations include fusion of villi, edema, disorganization of epithelial cells, epithelial abrasion, and flaking of the villus at mucosa layer level and submucosa layer with some regions of necrosis and lymphocyte infiltrate. This is the first report of histopathological alterations caused by infection of the atractid nematode R. rondoni in a farmed population of P. brachypomus in the Peruvian Amazon. The study points out the need of improving the strategies of parasitic prevention and control in order to better prevent future disease outbreaks.