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51.
Pathogenesis of porcine reproductive and respiratory syndrome virus infection in mid-gestation sows and fetuses. 总被引:9,自引:4,他引:5 下载免费PDF全文
W T Christianson C S Choi J E Collins T W Molitor R B Morrison H S Joo 《Canadian journal of veterinary research》1993,57(4):262-268
Two experiments were undertaken to evaluate whether porcine reproductive and respiratory syndrome (PRRS) virus was able to cross the placenta and infect midgestation fetuses following intranasal inoculation of sows and whether PRRS virus directly infected fetuses following in utero inoculation. In experiment 1, eight sows between 45 and 50 days of gestation were intranasally inoculated with PRRS virus (ATCC VR-2332), and four control sows were inoculated with uninfected cell culture lysate. Virus inoculated sows were viremic on postinoculation (PI) days 1, 3, 5, 7 and 9, shed virus in their feces and nasal secretions, and became leukopenic. Sixty-nine of 71 fetuses from principal sows euthanized on PI day 7, 14 or 21 were alive at necropsy and no virus was isolated from any of the fetuses. Two principal sows that farrowed 65 and 67 days PI delivered 25 live piglets and three stillborn fetuses. The PRRS virus was isolated from two live piglets in one litter. In experiment 2, laparotomies were performed on five sows between 40 and 45 days of gestation and fetuses were inoculated in utero with either PRRS virus alone, PRRS virus plus a swine serum containing PRRS antibodies, or uninfected cell culture lysate. Three sows were euthanized on PI day 4 and two sows on PI day 11. Viral replication occurred in fetuses inoculated with virus alone and was enhanced in fetuses inoculated with virus plus antibody. No virus was isolated from control fetuses.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
52.
Isolation of a cytopathic virus from weak pigs on farms with a history of swine infertility and respiratory syndrome. 总被引:6,自引:0,他引:6
I J Yoon H S Joo W T Christianson H S Kim J E Collins J H Carlson S A Dee 《Journal of veterinary diagnostic investigation》1992,4(2):139-143
Severe clinical signs of swine infertility and respiratory syndrome (SIRS) of unknown cause were observed in several Minnesota swine farms between November 1990 and March 1991. Forty-five lung samples of weak pigs were collected from 13 swine farms, and virus isolation was attempted using swine alveolar macrophage (SAM) cultures. A cytopathic virus was isolated from 19 lung samples collected from 6 different farms. Four pregnant sows were infected intranasally with a tissue suspension from which virus was isolated, and 4 6-week-old pigs and 2 contact pigs were infected intranasally with 1 of the isolates. The 4 sows farrowed 12 stillborn and 32 normal pigs. Virus was recovered from 10 of 19 pigs examined. Infected 6-week-old pigs were clinically normal except for slightly elevated rectal temperatures and mild respiratory signs. No or mild interstitial pneumonic lesions were observed in inoculated pigs, but the lesion was obvious in the 2 contact pigs. Seroconversion was observed in sows and pigs as measured by indirect fluorescent antibody (IFA). Serologic identification of the isolates was carried out by IFA using reference serum prepared from an experimentally infected sow. A cytoplasmic fluorescence was observed on the SAM monolayers infected with each of the 19 different isolates. Fluorescence was also observed when the monolayers were tested with SIRS virus ATCC VR-2332-infected sow sera. Replication of the isolates was not affected in the medium containing 5-iodo-2'-deoxyuridine but was inhibited by treatment with ether. The isolates were relatively stable at 56 C and did not agglutinate with various erythrocytes tested.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
53.
The storied nature of agriculture and evaluation: A conversation 总被引:2,自引:1,他引:1
54.
Joy E. Tomlinson Amit Kapoor Arvind Kumar Bud C. Tennant Melissa A. Laverack Laurie Beard Katie Delph Elizabeth Davis Harold Schott II Kara Lascola Todd C. Holbrook Philip Johnson Sandra D. Taylor Erica McKenzie Jessica Carter‐Arnold Emilie Setlakwe Lisa Fultz Jeff Brakenhoff Rebecca Ruby Sheetal Trivedi Gerlinde R. Van de Walle Randall W. Renshaw Edward J. Dubovi Thomas J. Divers 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2019,33(1):251-257
55.
Francis DA Millis DL Head LL 《Journal of the American Animal Hospital Association》2006,42(2):127-135
Following cranial cruciate ligament transection and extracapsular stabilization, dual-energy X-ray absorptiometry was used to analyze bone mineral content and lean tissue mass in the surgical and nonsurgical legs (n=14) at 0, 2, 4, and 8 weeks, and to evaluate bone mineral content and bone mineral density (BMD) of the proximal, mid-, and distal tibia of both the surgical and nonsurgical legs (n=15) at 0, 5, and 10 weeks. There was significant loss of bone mineral content and lean tissue in the surgical leg compared to the nonsurgical leg. Significant loss in bone mineral content and BMD was detected in the tibia of the surgical leg and was most pronounced in the metaphyseal region. 相似文献
56.
Katie Boes Kurt Zimmerman Geoffrey Saunders Laurie O'Rourke Natalie Crawford Christopher Ober Nicolaas Lambrechts Jonathan Miller 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2009,38(4):511-515
Abstract: An adult castrated male Golden Retriever of unknown age was presented with a history of weight loss and progressive left thoracic limb lameness. On physical examination, a solid mass was palpated on the left scapula that had areas of lysis on radiographs and an area of cortical bone loss on ultrasound. Hepatomegaly, abdominal distension, and numerous intra‐abdominal soft tissue masses were also found. Fine‐needle aspirates of the scapula and several abdominal masses contained numerous free nuclei mixed with fewer individualized, intact cells that were round in shape and rarely formed small sheets. The cells had high nuclear to cytoplasmic ratios, central nuclei, coarsely stippled chromatin, 1–2 prominent nucleoli, and basophilic cytoplasm with indistinct cell borders. The cytopathologic interpretation was neuroendocrine neoplasia, either metastatic or multicentric. The dog was subsequently euthanized and based on gross and histologic findings at necropsy, a diagnosis of pheochromocytoma with multiple metastases was made. The neoplastic cells stained positive with Grimelius stain and were immunoreactive for synaptophysin and chromogranin A. Pheochromocytomas are rare tumors in dogs and uncommonly undergo distant metastasis, especially to bone. 相似文献
57.
Simeon John Smaill Peter W. Clinton Laurie G. Greenfield 《Biology and Fertility of Soils》2010,46(4):309-316
The effect of variations in organic matter removal during harvesting on microbial biomass nitrogen was determined in four
Pinus radiata plantations between 9 and 17 years after harvesting. Variation in microbial biomass nitrogen with season and the response
of net nitrogen mineralization to organic matter removal after 9 and 17 years were also determined at two of the sites. The
microbial biomass nitrogen in the fermentation-humus (FH) layer was correlated with litter fall characteristics and did not
vary with organic matter removal, but the total mass of microbial biomass nitrogen in the FH layer was significantly reduced
by increased organic matter removal. The microbial biomass nitrogen in the mineral soil was decreased by increased organic
matter removal and was strongly correlated with moisture content and total nitrogen concentration. The FH layer microbial
biomass nitrogen did not vary with season, but mineral soil microbial biomass nitrogen varied with season at one site, probably
due to increased moisture availability. Net nitrogen mineralization in the mineral soil, determined by an anaerobic incubation,
was decreased by increased organic matter removal and was strongly correlated with microbial biomass nitrogen. The persistence
of the significant differences in microbial biomass nitrogen and net nitrogen mineralization indicated that variations in
organic matter removal during harvesting have long-term effects on soil microbial properties and activity during the life
of the subsequent rotation. This has implications for the selection of harvesting techniques to promote the maintenance of
site productivity and to minimise disruption to the soil biota. 相似文献
58.
59.
McGhee JD White NA Goodrich LR 《Journal of the American Veterinary Medical Association》2005,226(1):83-86
OBJECTIVE: To determine clinical and ultrasonographic abnormalities in horses with primary desmitis of the palmar or plantar annular ligament (PAL) and the response to treatment. DESIGN: Retrospective study. ANIMALS: 25 horses. PROCEDURE: Data collected from medical records included signalment, horse use, affected limb, severity and duration of lameness, results of diagnostic tests performed, ultrasonographic findings, treatment, and outcome. RESULTS: All horses had a prominent swelling in the region of the affected PAL, and signs of pain were evident during palpation of the swelling. In all horses, the affected PAL was thicker than normal as determined ultrasonographically. Twenty horses had hypoechoic regions in the PAL. Four horses, including 1 horse with 3 affected limbs, were treated by means of PAL desmoplasty, 9 were treated by means of PAL desmotomy, and 12 were treated with rest. Follow-up information was available for 21 horses. All 4 horses that underwent PAL desmoplasty, 4 of 7 horses that underwent PAL desmotomy, and 7 of 10 horses treated with rest alone became sound. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that primary desmitis of the PAL may be a cause of lameness in horses. Although significant differences in outcome between horses treated with rest alone versus PAL desmoplasty versus PAL desmotomy were not identified, because it is less invasive, PAL desmoplasty should be considered for treatment of horses with PAL desmitis that do not respond to conservative treatment and do not have any evidence of constriction of the digital flexor tendons. 相似文献
60.
Hart BL Cliff KD Tynes VV Bergman L 《Journal of the American Veterinary Medical Association》2005,226(3):378-382
OBJECTIVES: To determine whether clomipramine differs from fluoxetine in reducing feline urine marking; whether reduction of marking continues in cats treated >8 weeks; whether recurrence of marking, after abrupt drug withdrawal, is less in cats treated >8 weeks; and whether cats that are successfully treated but resume marking after drug withdrawal can be successfully treated again with the same drug regimen. DESIGN: Positive-controlled, double-masked clinical trial. ANIMALS: 22 neutered cats (2 females, 20 males) > or =1 year old with objectionable urine marking. PROCEDURE: Cats that marked vertically > or =3 times/wk were treated with fluoxetine (1 mg/kg [0.45 mg/lb], q 24 h, PO) or clomipramine (0.5 mg/kg [0.23 mg/lb], q 24 h, PO) for 16 weeks, and efficacy was compared. Recurrence of marking was determined after abrupt withdrawal of fluoxetine at 16 or 32 weeks. Reduction in marking in cats treated with fluoxetine for 8 weeks after returning to marking following drug withdrawal was compared with the initial 8 weeks of successful treatment. RESULTS: Efficacy of fluoxetine and clomipramine was similar. Treatment >8 weeks revealed increasing efficacy in reduction of marking. Return of marking after termination of fluoxetine administration occurred in most cats. Cats successfully treated initially with fluoxetine responded similarly to repeated treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Clomipramine and fluoxetine were equivalent in treating urine marking. Longer treatment increased efficacy. Most cats return to marking after abrupt drug withdrawal. A second course of treatment can be expected to be as effective as the first. 相似文献