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181.
Molecular structure of troponin C from chicken skeletal muscle at 3-angstrom resolution 总被引:19,自引:0,他引:19
M Sundaralingam R Bergstrom G Strasburg S T Rao P Roychowdhury M Greaser B C Wang 《Science (New York, N.Y.)》1985,227(4689):945-948
The x-ray structure of chicken skeletal muscle troponin C (TnC), the Ca2+-binding subunit of the troponin complex, shows that the protein is about 70 angstroms long with an unusual dumbbell shape. The carboxyl and amino domains are separated by a single long alpha helix of about nine turns. Only the two high-affinity Ca2+-Mg2+ sites of the COOH-domain are occupied by metal ions resulting in conformational differences between the COOH- and NH2-domains. These differences are probably important in the triggering of muscle contraction by TnC. Also the structure of TnC is relevant in understanding the function of other calcium-regulated proteins, in particular that of calmodulin because of its strong similarity in amino acid sequence. 相似文献
182.
Veterinary Research Communications - 相似文献
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185.
W Donachie C Burrells A D Sutherland J S Gilmour N J Gilmour 《Veterinary immunology and immunopathology》1986,11(3):265-279
Specific pathogen-free (SPF) lambs previously exposed to an aerosol of P. haemolytica biotype A serotype 2 (A2) were immune to subsequent challenge with an aerosol of P. haemolytica A2. Untreated control lambs were not immune to this challenge. The local immune responses of the lung to these challenges were examined. High IgG and IgA titres to P. haemolytica and high levels of opsonizing antibody against P. haemolytica were present in the lung washings from previously infected immune lambs at autopsy, seven days after the second infection. Lung washings from control lambs, 7 days after challenge with P13 virus and P. haemolytica A2, had no IgG titres, very little opsonizing activity but did have IgA titres which were significantly higher than in unchallenged control lambs. The cellular response of animals challenged with P13 virus and P. haemolytica was significantly greater than that of unchallenged controls or of lambs exposed only to P. haemolytica. However, this finding was complicated by the response to P13 virus. Lymphocytes from lung washings of all lambs failed to respond in a lymphocyte stimulation test to phytohaemagglutinin while blood lymphocytes did respond. There was little specific response to P. haemolytica antigen in the test. 相似文献
186.
Since 1993, 14 cases of avian influenza from four different states in the U.S.A. have been diagnosed by virus isolation from eight avian species. Only 11 of the 14 avian influenza virus (AIV) primary isolations would have been successful if only the standard protocol for AIV isolation, i.e., inoculation of specific-pathogen-free embryonating chicken eggs (ECEs) by the chorioallantoic sac (CAS) route, had been followed. Primary isolation attempts were negative for AIV in three cases in which ECEs were inoculated by the CAS route; AIV could not be detected by hemagglutinating activity, agar gel immunodiffusion test or negative stain electron microscopy. However, in these three cases, primary isolations of AIV were achieved by inoculation of ECEs into either the yolk sac or onto the chorioallantoic membrane. 相似文献
187.
188.
M Kennedy S Citino T Dolorico A H McNabb A S Moffat S Kania 《Journal of zoo and wildlife medicine》2001,32(1):25-30
Feline coronavirus genetic elements were detected by polymerase chain reaction from blood, fecal samples, and effusive fluid collected from 33 cheetahs in the U.S.A. Feline coronavirus-specific serum antibodies were also measured by indirect immunofluorescence. Ten cheetahs were positive for viral shedding by polymerase chain reaction, whereas 13 were seropositive by immunofluorescence. Results of serology did not consistently correlate with shedding of virus, and the capture antigen used for detection of feline coronavirus-specific antibodies had a significant impact on results. Testing of samples from one population over a 1-yr period indicated chronic infection in some animals. These relatively healthy carrier animals were a source of virus for contact animals. Screening programs in cheetah populations for feline coronavirus infection may be most reliable if a combination of serologic analysis and viral detection by polymerase chain reaction is used. 相似文献
189.
Sean G. Sanders DVM Russell L. Tucker DVM Rodney S. Bagley DVM Patrick R. Gavin DVM PhD 《Veterinary radiology & ultrasound》2001,42(4):291-296
Magnetic resonance imaging (MR) was used to make a diagnosis of equine nigropallidal encephalomalacia in a horse. Equine nigropallidal encephalomalacia is a neurodegenerative disease that has many characteristics with Parkinson-like diseases in humans. Historically, horses were euthanized based on clinical signs and exposure to the toxic weed, yellow star thistle (Centaurea solstitialis). Previously, the disease has only been confirmed on necropsy. MR imaging can provide accurate and sensitive visualization of typical lesions seen in the brain of horses affected with equine nigropallidal encephalomalacia. Lesions were seen on T1-weighted, T2-weighted and proton density images. There was no contrast enhancement following Gd-DTPA administration. Lesions seen on MR were confirmed at necropsy. Using MR to confirm a diagnosis of equine nigropallidal encephalomalacia will prevent unnecessary suffering of horses and expense to owners that would otherwise incur, while further diagnostics are performed. 相似文献
190.
R B Duncan C B Carrig J S Agerholm C Bendixen 《Journal of veterinary diagnostic investigation》2001,13(4):333-336
Complex vertebral malformation (CVM), a familial syndrome of Holstein calves, has been reported in aborted fetuses and in prematurely born, stillborn, and neonatal calves. Affected calves have anomalies in the vertebral column, including hemivertebrae, fused and misshapen vertebrae and ribs, scoliosis, and vertebral synostosis. Concurrent low body weight, symmetrical arthrogryposis, and cardiac anomalies have been documented in affected calves. The syndrome was identified and characterized in Holstein cattle in Denmark; however, a global distribution of this genetic disorder is likely based on identification of common ancestral sires widely used for artificial insemination. This is the first documented case of CVM in a Holstein calf in the USA. 相似文献