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   

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   

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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Characteristics of phosphorus accumulation in soils under organic and conventional farming in plastic film houses in Korea     

Pil Joo Kim  Doug Young Chung  Douglas Malo 《Soil Science and Plant Nutrition》2013,59(2):281-289

Organic farming (OF) is a fast growing alternative for sustainable agriculture in Korea. However, information on the effects of OF on the soil properties and environmental conservation is limited. In order to determine the effects of OF on the soil properties, 31 fields under OF (hereafter referred to as "OF fields") and 61 fields under conventional farming (CF) (hereafter referred to as "CF fields") in plastic film houses were selected throughout Korea and the soil chemical properties were investigated, including the P distribution characteristics. Average organic matter (OM) content was significantly higher (44 g kg^-1) in the OF fields then in the CF fields (24 g kg^-1). Bray-2 P values were 986 and 935 mg kg^-1 in the OF and CF soils, respectively, markedly exceeding the optimum range. Average total P (T-P) values were 2,973 mg kg^-1 in the OF fields and 1,830 mg kg^-1 in the CF fields. The high T-P values were due to repeated application of manure compost with a low N/P ratio. Inorganic P was the dominant fraction with 62–65% of T-P. The amounts of residual and organic P were significantly lower. The level of OF organic P was significantly higher (453 mg kg^-1) compared to the 106 mg kg^-1 value for the CF fields. Fractionation of soil inorganic P showed that Ca-P predominated with 1,332 mg kg^-1 in the OF fields, which was associated with soil pH values over 6.0. The main inorganic P fraction in the CF soils whose pH values were generally less than 6.0 consisted of Al-/Fe-P. The levels of water-soluble P was significantly higher (65 mg kg^-1) in the OF fields than in the CF fields (24 mg kg^-1). These results indicated that the OF system may lead to a serious degradation of the soil environment due to the accumulation of phosphorus and may be an important source of water pollution compared to the CF systems in Korea.  相似文献   

Sensibilité à l'halothane dans quelques élevages de porcs Landrace au Québec          下载免费PDF全文

Lafortune AM  Malo D  Nadeau S  Deroth L 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(1):50-51

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Entéropathie, avec perte de protéines, secondaire à une lymphangiectasie intestinale, chez trois chiens          下载免费PDF全文

Malo D  Gosselin Y  Papageorges M 《The Canadian veterinary journal. La revue veterinaire canadienne》1982,23(4):129-131

Protein-losing enteropathy secondary to intestinal lymphangiectasia in three dogs

Three cases of protein-losing enteropathy secondary to intestinal lymphangiectasia in the dog are presented.

In the three cases, common clinical findings were nonresponsive diarrhea and weight loss. Subcutaneous edema was observed in case 1. Polyphagia and polydipsia were evident in cases 2 and 3.

Serum examinations revealed low values of protein with a normal albumin/globulin ratio. There was histopathological evidence of dilatation of lacteals, as well as plasma cell and lymphocyte infiltration in the small intestine.

In the three cases, a corticotherapy was instituted and gave good results.

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