Activities of gastric,pancreatic, and intestinal brush-border membrane enzymes during postnatal development of dogs     

Buddington RK  Elnif J  Malo C  Donahoo JB 《American journal of veterinary research》2003,64(5):627-634

OBJECTIVE: To measure activities of digestive enzymes during postnatal development in dogs. SAMPLE POPULATION: Gastrointestinal tract tissues obtained from 110 Beagles ranging from neonatal to adult dogs. PROCEDURE: Pepsin and lipase activities were measured in gastric contents, and amylase, lipase, trypsin, and chymotrypsin activities were measured in small intestinal contents and pancreatic tissue. Activities of lactase, sucrase, 4 peptidases, and enteropeptidase were assayed in samples of mucosa obtained from 3 regions of the small intestine. RESULTS: Gastric pH was low at all ages. Pepsin was not detected until day 21, and activity increased between day 63 and adulthood. Activities of amylase and lipase in contents of the small intestine and pancreatic tissue were lower during suckling than after weaning. Activities of trypsin and chymotrypsin did not vary among ages for luminal contents, whereas activities associated with pancreatic tissue decreased between birth and adulthood for trypsin but increased for chymotrypsin. Lactase and gamma-glutamyltranspeptidase activities were highest at birth, whereas the activities of sucrase and the 4 peptidases increased after birth. Enteropeptidase was detected only in the proximal region of the small intestine at all ages. CONCLUSIONS AND CLINICAL RELEVANCE: Secretions in the gastrointestinal tract proximal to the duodenum, enzymes in milk, and other digestive mechanisms compensate for low luminal activities of pancreatic enzymes during the perinatal period. Postnatal changes in digestive secretions influence nutrient availability, concentrations of signaling molecules, and activity of antimicrobial compounds that inhibit pathogens. Matching sources of nutrients to digestive abilities will improve the health of dogs during development.  相似文献   

禽流感病毒抗原超滤浓缩重要参数的动态变化     

张彦杰  李爱芬 《中国兽药杂志》2007,41(10):16-17

采用世界先进的切向流超滤浓缩技术，对禽流感病毒（H9N2亚型）超滤浓缩成倍体积，测定血凝价HA和半数感染量EID50。结果HA成倍增加，废液HA呈阴性，病毒回收率达100％；受宿主鸡胚系统的影响，EID50与病毒量之间不是简单的直线关系，但病毒的活性不受影响。结果表明，所用超滤系统适用于禽流感病毒抗原的浓缩。  相似文献   

Infectivity of Cryptosporidium sp isolated from wild mice for calves and mice   总被引：4，自引：0，他引：4  

P H Klesius  T B Haynes  L K Malo 《Journal of the American Veterinary Medical Association》1986,189(2):192-193

A study was conducted to determine the incidence of cryptosporidiosis in wild mice (Mus musculus) and the infectivity of oocysts from their feces for susceptible calves. The presence of oocysts and the duration of shedding of oocysts in the feces were evaluated in 115 wild mice. Approximately 30% of the mice shed Cryptosporidium sp oocysts, without evidence of clinical infection; recurrence of oocyst shedding was found in about 50% of the mice. Oocysts from the feces of naturally infected mice were infective for calves and mice. Calves began shedding oocysts at 7 days and shed oocysts for about 10 days. Nonfatal, clinical cryptosporidiosis developed in 7 infected calves. The mice began shedding oocysts at 6 days and shed oocysts for 12 days. Fatalities or clinical infection did not develop in 5 infected mice. The results indicated that Cryptosporidium-infected wild mice may be a source of cryptosporidiosis in susceptible calves.  相似文献   

Scanning electron microscopic studies of changes in the respiratory tract of chicks caused by an infection with the agent of infectious bronchitis     

A Malo  J Speck 《DTW. Deutsche tier?rztliche Wochenschrift》1988,95(7):296-300

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Diagnostic des rickettsiales au laboratoire          下载免费PDF全文

R. Malo 《The Canadian veterinary journal. La revue veterinaire canadienne》1975,16(8):237

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Moisture-induced stresses in glulam cross sections during wetting exposures     

Vanessa Angst  Kjell Arne Malo 《Wood Science and Technology》2013,47(2):227-241

Moisture-induced stresses resulting from climate variations of the environment can induce cracks in timber members and thus affect the safety and serviceability. The present study highlights—by means of numerical simulations—the distribution and development over time of moisture-induced stresses in various glulam cross sections during wetting. The results show that local stresses may be significantly larger than average stresses, the extent of which strongly depends on the geometrical configuration of the glulam laminates. Suggestions are made on the design of glulam cross sections to minimize the arising local stresses. Furthermore, the studied wetting exposure results in local tensile stresses that exceed the tensile strength of the material. In smaller cross sections, this is the case within few days, while more time is required in wider cross sections.  相似文献   

Possible parachordoma in a dog     

SF Forsyth  KG Thompson  AF French  TR Halsey 《New Zealand veterinary journal》2013,61(5):299-302

Abstract

CASE HISTORY: A 15-mm diameter mass developed in the S/C tissue overlying the right lateral gluteal muscle of a 6½-year-old female Flat-coated Retriever.

PATHOLOGICAL FINDINGS: Cytological preparations following aspiration of the mass were highly cellular and consisted of a population of large polygonal cells containing single to multiple nuclei, large prominent nucleoli, and intracytoplasmic vacuoles. Histologically, the neoplasm consisted of similar large cells surrounded by thick fibrous connective tissue trabeculae. The large polygonal cells reacted positively with antibodies against vimentin, low- and high-molecular-weight variants of cytokeratin (AE1/AE3), but not with antibodies to desmin or glial fibrillary acidic protein (GFAP).

DIAGNOSIS: The clinical, gross, histological and immunohistochemical findings are similar to those reported for parachordomas in humans. Neither recurrence nor metastases were noted 18 months after surgical excision of the mass.

CLINICAL RELEVANCE: This is the first reported case of a possible parachordoma in a dog, a benign tumour with cytological features of malignancy.  相似文献   

Geographic variation in pheromone component ratio and antennal responses,but not in attraction,to sex pheromones among fall armyworm populations infesting corn in Mexico   总被引：2，自引：0，他引：2  

Samuel Cruz-Esteban  Julio C. Rojas  Daniel Sánchez-Guillén  Leopoldo Cruz-López  Edi A. Malo 《Journal of pest science》2018,91(3):973-983

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is one of the most important pests of corn in Latin America. This insect presents two strains with behavioural and genetic differences. In Mexico, both strains are present, and at least two different FAW populations have been reported within the corn-strain. The objective of this study was to gather evidence of whether pheromonal communication varies among different S. frugiperda populations infesting corn in Mexico. First, we investigated any qualitative or quantitative difference in the composition of sex pheromones among populations; second, we studied whether male antennal responses to pheromone components vary among populations; and, finally, we investigated whether males from a region can discriminate between a synthetic pheromone blend characteristic of their region and blends formulated with the ratio of pheromone compounds emitted by females from other populations. Sex pheromone components were sampled by solid-phase microextraction and identified by gas chromatography coupled to mass spectrometry. Females from all populations consistently released three compounds: (Z)-9-tetradecenyl acetate (Z9-14:OAc), (Z)-11-hexadecenyl acetate (Z11-16:OAc) and (Z)-7-dodecenyl acetate (Z7-12:OAc). Our results showed that Z9-14:OAc and Z7-12:OAc evoked the highest and most variable antennal responses among the populations studied compared to Z11-16:OAc. However, males did not discriminate between local pheromone blends and those formulated from other populations in a field test. These results show that although there is geographic variation in the ratio of pheromone components and in the peripheral reception of them, males were not differentially attracted to different pheromone blends in the field.  相似文献   

Mass trapping is as effective as ground bait sprays for the control of Anastrepha (Diptera: Tephritidae) fruit flies in mango orchards          下载免费PDF全文

Jorge Villalobos  Salvador Flores  Pablo Liedo  Edi A Malo 《Pest management science》2017,73(10):2105-2110

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The Comet assay for detection of DNA damage in canine sperm          下载免费PDF全文

AF Pereira  P Borges  A Fontbonne  L Cardoso  I Gaivão  A Martins‐Bessa 《Reproduction in domestic animals》2017,52(6):1149-1152

Sperm DNA integrity is a fundamental prerequisite in fertilization and embryo development. Among DNA integrity tests, the Comet assay is an accurate and sensitive test for the detection of sperm oxidative damage. The aim of this work was to evaluate sperm oxidative damage using the Comet assay and to study the correlation between Comet and routine assays for the evaluation of semen quality. Dogs were divided in two groups: group A (n = 6), comprising dogs with abnormal spermiogram, that is astheno‐, terato‐ or oligoasthenoteratozoospermic (OAT); and group B (n = 8), comprising normospermic dogs. The distribution of sperm oxidative damage was significantly different between the two groups (p = .001): group A—median: 31.55%, interquartile range (IQR): 30.18–38.01; group B—median: 0.90%, IQR: 0.65–1.96. The correlation between oxidative damage and abnormal morphology was high (r = .846; p < .001). There was a negative correlation between progressive motility and oxidative damage (r = ?.792; p = .001). Basal and oxidative DNA damage of spermatozoa are increased in dogs with non‐normospermic semen. In conclusion, and considering the elevated correlation with classical tests of sperm quality, the Comet assay has ample potential for clinical and research purposes in dogs.  相似文献