EQUIPMENT NEWS     

Stern J 《Science (New York, N.Y.)》1957,125(3254):950

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Equipment     

Stern J 《Science (New York, N.Y.)》1958,128(3322):486-488

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Equipment     

Stern J 《Science (New York, N.Y.)》1958,128(3315):99

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EQUIPMENT NEWS     

Stern J 《Science (New York, N.Y.)》1958,127(3295):436

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Equipment     

Stern J 《Science (New York, N.Y.)》1959,129(3343):226

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Equipment     

Stern J 《Science (New York, N.Y.)》1958,128(3317):214

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Influence of Campylobacter jejuni cecal colonization on immunoglobulin response in chickens   总被引：1，自引：0，他引：1  

M A Myszewski  N J Stern 《Avian diseases》1990,34(3):588-594

The immunoglobulin response of chickens to colonization by Campylobacter jejuni isolates B-540 and Clin-1 was monitored. Chicken humoral IgG and biliary secretory IgA (sIgA) responses were assessed by enzyme-linked immunosorbent assay (ELISA). Samples were taken from 128 C. jejuni-colonized chickens and 104 uncolonized chickens housed in a controlled environment. An indirect ELISA was performed using the homologous isolate of C. jejuni as the capture antigen and was developed with the specific goat anti-chicken IgG or IgA alkaline phosphatase conjugates. The ELISA absorbance values of the test samples at 405 nm (serum diluted 1:32 and bile diluted 1:10) were normalized in direct proportion to standard sera and bile sample values. In the colonized chickens, humoral IgG activities were highest at hatch, dropped to their lowest level after 2 weeks, and increased by 8 weeks to levels similar to those detected at hatch. The sIgA activity was lowest at hatch and increased by 4 weeks in colonized chickens while remaining lower in the control chickens. Chickens colonized with isolate B-540 showed a primary sIgA response during the first 4 weeks and reached a plateau over the final 4 weeks. In spite of these limited humoral and secretory immunoglobulin responses, once the chicken ceca was colonized by C. jejuni, the organism persisted throughout the 8-week experiment.  相似文献   

Evaluation of various nitrogen supplements in starter diets for growing Holstein steers and their effects on ruminal bacterial fermentation in continuous culture   总被引：2，自引：0，他引：2  

H Chester-Jones  M D Stern  A Su  J D Donker  D M Ziegler  K P Miller 《Journal of animal science》1990,68(9):2954-2964

Concurrent in vivo and in vitro studies were conducted to evaluate urea (U), soybean meal (SBM), ground soybeans (RAW), extruded soybeans (ES) or extruded soybeans plus urea (ES + U) as primary supplemental N sources in starter diets for Holstein steers. Three groups of 48 Holstein steers each were fed five different starter diets to 181 kg BW in three experimental periods over 2 yr. Average daily gains were similar (P greater than .05) for steers fed ES + U (1.12 kg), ES (1.08 kg) and SBM (1.09 kg) but lower (P less than .05) for those fed U (1.00 kg) or RAW (.97 kg) diets. Feed/gain was similar (P greater than .05) for ES-fed steers vs those fed other diets except U. From 181 to 477 kg, all steers were fed the same diet. Steers fed the RAW starter diet had the lowest (P less than .05) ADG for the entire period. The starter diets were used as substrates for ruminal microbial metabolism in eight dual-flow continuous culture fermenters. True OM digestion was higher and NDF and ADF digestion was lower (P less than .05) for the ES + U diet than for the ES diet. Dietary protein degradation was lowest (P less than .05) for the ES diet (64.4%). Total bacterial N flow was higher (P less than .05) with the ES + U, SBM and U diets than with the ES diet. Lysine flow was higher (P less than .05) for the ES + U diet than for all other diets except ES. Results of these experiments indicate that ES as a protected ruminal escape N source with or without added urea did not improve steer performance above that obtained from SBM in starter diets.  相似文献   

Colonization characteristics of Campylobacter jejuni in chick ceca   总被引：7，自引：0，他引：7  

N J Stern  J S Bailey  L C Blankenship  N A Cox  F McHan 《Avian diseases》1988,32(2):330-334

We report our findings on several parameters influencing cecal colonization of chickens by Campylobacter jejuni. Thirty-five colony-forming units (CFU) of a composite culture of C. jejuni colonized the ceca of one-half of the newly hatched chicks challenged by oral gavage. A challenge dose of 3500 CFU/chick consistently colonized the ceca of all chicks challenged. Challenge doses of approximately 10(5) CFU of C. jejuni per chick resulted in consistent cecal colonization, regardless of whether the birds were challenged 1, 2, or 3 days post-hatch. Four isolates showed consistently strong cecal colonization abilities, whereas two isolates colonized the ceca in only 20 of 122 chicks when given levels of 10(5) CFU per chick. One of these poorly colonizing isolates was repeatedly transferred by fecal-oral passage through chicks; subsequently, this isolate was able to consistently colonize chicks. Competitive exclusion (CE) microflora did not diminish the colonization rates for C. jejuni. Birds treated with five different CE cultures were colonized at a rate of 81 of 84 chicks; control chicks were similarly consistently colonized (45 of 46 chicks).  相似文献   

Effects of an anticholinergic and a corticosteroid on acute pancreatitis in experimental dogs     

E Attix  D R Strombeck  E B Wheeldon  J S Stern 《American journal of veterinary research》1981,42(10):1668-1674

In a model developed to study acute pancreatitis in the dog, the disease process was comparable with the spontaneously occurring disease. Infusion of oleic acid into the accessory pancreatic duct induced, grossly and microscopically, acute hemorrhagic pancreatitis with pancreatic atrophy, fibrosis, fat necrosis, and edema. Clinical changes included persistent fever and tachycardia in all dogs and abdominal pain, vomiting, and diarrhea in most. Serum amylase and lipase activities increased markedly as did activities of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase. Hematologic alterations included hemoconcentration (despite intensive fluid therapy) and leukocytosis due primarily to neutrophilia and monocytosis. Neither corticosteroid nor anticholinergic therapy begun 24 to 32 hours after oleic acid infusion altered the course of the disease. Dogs survived 8 days and appeared clinically normal when the study was terminated.  相似文献