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971.
A total of 5586 indigenous and cross breed cattle were examined for clinical dermatophilosis, and 292 (5.22%) were positive. In indigenous cattle, statistically discernible (p < 0.05) difference was recorded between the prevalence in wet (5.5%) and dry (4.0%) seasons. During both seasons, infestation with A. Variegatum significantly (p < 0.05, chi 2 = 59.9) influenced clinical dermatophilosis. A. variegatum-infested cattle were at 7x higher risk (OR, Odds Ratio = 6.8) of acquiring the disease than non-infested ones. Logistic regression analysis of the overall prevalence showed a significant difference (p < 0.05) between prevalence in indigenous and cross breeds; the crossbreeds being at about 3x higher risk (OR = 2.68). Improved management reduced the prevalence in cross breeds from 15.1% in dry to 8.6% in wet season suggesting the significance of management in the epidemiology of dermatophilosis. The disease occurrence was also significantly (p < 0.05, chi 2 = 133.05) affected by agro-climatic (altitude) variation suggesting the impact of rainfall, humidity, vegetation and vector population that varied with altitude. Age and gender had no influence (p > 0.05) on the disease. Our result showed that season of the year, breed, management, infestation with A. variegatum and agro climatic difference are important risk factors influencing the disease pattern in the region. A tick control strategy and a better and adequate management particularly when keeping cross breeds are recommended. 相似文献
972.
Adherence to various host cell lines of Mycoplasma bovis strains differing in pathogenic and cultural features 总被引:1,自引:0,他引:1
Thomas A Sachse K Dizier I Grajetzki C Farnir F Mainil JG Linden A 《Veterinary microbiology》2003,91(2-3):101-113
Mycoplasma bovis is known to be responsible for pneumonia and arthritis in calves, as well as mastitis in dairy cows. Despite clear evidence of its pathogenic potential, little is known about mechanisms of cytadherence and the molecular factors involved. The purpose of this work was to compare adherence rates of M. bovis field strains to different host cell lines and study the effects of cloning and sub-culturing M. bovis strains on their adherence properties. Eighteen metabolically labeled M. bovis strains isolated from different pathological backgrounds were examined in adherence trials using four different host cell lines, i.e. embryonic bovine lung (EBL), embryonic bovine trachea (EBTr), Madin Darby bovine kidney (MDBK) and rabbit kidney (RK) cells. Although large interstrain variations in adherence rates (3.4-19.1%) were measured they could not be correlated to the pathological background (pneumonia, arthritis or mastitis). Adherence rates to the fibroblast cell line (EBTr) were significantly lower than those to the three epithelial cell lines (EBL, MDBK and RK). The only non-pathogenic strain (221/89) exhibited lower adherence rates than three isolates from clinical mastitis. Interestingly, adherence rates were significantly reduced after in vitro passaging. In contrast, no effect of single cloning of strains on adherence was observed. There was no general correlation between expression of variable surface proteins (Vsps) as monitored by immunoblotting and adherence rates, although alterations in Vsp expression profiles were seen as a consequence of passaging. As there is probably a large number of adhesins, variable and non-variable, on the surface of M. bovis cells the issue is very complex, and the most active components have yet to be identified. 相似文献
973.
REASONS FOR PERFORMING STUDY: Studies on the prevalence of behavioural disorders in horses and on associated risk factors have revealed inconsistent results. There are many studies on the neuropharmacological, surgical or mechanical therapy of stereotypies, but little is known about their causation. OBJECTIVES: To explore risk factors associated with the occurrence of behavioural disorders in horses. METHODS: A sample of horse owners, selected randomly and representative for Switzerland, was contacted in a postal survey. Answers were provided for 622 stables (response rate 35.2%). Individual data of 2,341 horses were examined with path analysis (multivariable linear and logistic regression), and adjustment made for possible confounding effects due to age and breed. RESULTS: Out of 60 possible risk factors, 11 were associated with the outcome at the univariable level (null-hypothesis path model) and 3 factors remained after the backward logistic regression procedure. Mature Warmbloods and Thoroughbreds, assessed by the owners to be reactive, fed 4 times a day and without daily pasture, had increased odds of displaying crib-biting, weaving and box-walking. Furthermore, indirect associations of 5 factors with the outcome were identified. CONCLUSIONS: The final logistic regression model of risk factors leads to the hypotheses that causal prevention of stereotypic behaviours should be based upon housing and management conditions which allow tactile contact with other horses (e.g. mutual grooming), daily free movement (paddock or pasture), as well as the provision of high amounts of roughage but of little or no concentrates. POTENTIAL CLINICAL RELEVANCE: It is one of the aims of population medicine to prevent the development of behavioural disorders. Further research is needed to test the concluding hypotheses in experimental studies or to verify them in the context of similar observational studies. 相似文献
974.
Wright IM Smith MR Humphrey DJ Eaton-Evans TC Hillyer MH 《Equine veterinary journal》2003,35(6):613-619
REASONS FOR PERFORMING STUDY: Contamination and infection of synovial cavities are a common occurrence in clinical practice and, if inadequately treated, may have career or life threatening consequences for affected horses. HYPOTHESIS: The objectives in treating contamination and infection of joints, tendon sheaths and bursae are most effectively met by endoscopic surgery. METHODS: Over a 6 year period, cases of synovial contamination and infection admitted to a referral clinic were evaluated and treated endoscopically. The horses received local and systemic antimicrobial drugs with minimal nonsteroidal anti-inflammatory medication but no other medical or surgical treatment. All arthroscope and instrument portals and, whenever possible, all traumatic wounds were closed. Diagnostic information, endoscopic observations and results of treatment were evaluated retrospectively. RESULTS: A total of 140 affected animals were referred and 121 cases were treated endoscopically. These involved 70 joints, 29 tendon sheaths, 10 bursae and in 12 cases a combination of synovial cavities. The most common aetiologies were open wounds (n = 54) and self-sealing punctures (n = 41). Foreign material was identified endoscopically in 41 but predicted prior to surgery in only 6 cases. Osteochondral lesions were evident at surgery in 51 and recognised before surgery in 25 cases; 32 horses had intrathecal tendon or ligament defects. Follow-up information was obtained for 118 animals; 106 (90%) survived and 96 (81%) returned to their preoperative level of performance. The presence of osteitis/osteomyelitis, other osteochondral lesions and marked deposits of pannus were associated with nonsurvival. For those animals which survived, non-Thoroughbred horses, a combination of synovial structure involvement and regional i.v. antimicrobial administration were associated with reduced post operative performance. Marked pannus, regional i.v. antimicrobial administration and duration of systemic antimicrobial administration were associated with a group combining nonsurviving animals and those with reduced post operative performance. CONCLUSIONS: Endoscopic surgery makes a valuable contribution to the management of synovial contamination and infection. POTENTIAL RELEVANCE: The information obtained from and therapeutic options offered by endoscopy justify its early use in cases of synovial contamination and infection. 相似文献
975.
Ovid'ko IA 《Science (New York, N.Y.)》2002,295(5564):2386
976.
Starai VJ Celic I Cole RN Boeke JD Escalante-Semerena JC 《Science (New York, N.Y.)》2002,298(5602):2390-2392
Acetyl-coenzyme A (CoA) synthetase (Acs) is an enzyme central to metabolism in prokaryotes and eukaryotes. Acs synthesizes acetyl CoA from acetate, adenosine triphosphate, and CoA through an acetyl-adenosine monophosphate (AMP) intermediate. Immunoblotting and mass spectrometry analysis showed that Salmonella enterica Acs enzyme activity is posttranslationally regulated by acetylation of lysine-609. Acetylation blocks synthesis of the adenylate intermediate but does not affect the thioester-forming activity of the enzyme. Activation of the acetylated enzyme requires the nicotinamide adenine dinucleotide-dependent protein deacetylase activity of the CobB Sir2 protein from S. enterica. We propose that acetylation modulates the activity of all the AMP-forming family of enzymes, including nonribosomal peptide synthetases, luciferase, and aryl- and acyl-CoA synthetases. These findings extend our knowledge of the roles of Sir2 proteins in gene silencing, chromosome stability, and cell aging and imply that lysine acetylation is a common regulatory mechanism in eukaryotes and prokaryotes. 相似文献
977.
OBJECTIVE: To determine whether the bispectral index (BIS) can be used as an indicator of degree of CNS depression in isoflurane-anesthetized horses. ANIMALS: 10 Standardbred and 6 Norwegian cold-blooded trotter stallions admitted for routine castration. PROCEDURE: A 2-channel referential electrode configuration was used to record EEG for calculation of BIS by the EEG monitor. The BIS was calculated before (awake) and after (sedated) administration of detomidine (0.01 mg/kg of body weight, IV) and butorphanol (0.01 mg/kg, IV). Anesthesia was induced with ketamine hydrochloride (2.5 mg/kg, IV) and diazepam (0.04 mg/kg, IV) and maintained with isoflurane delivered in oxygen. The BIS was calculated after 30 minutes of equilibration at an end-tidal isoflurane concentration of 1.4% (n = 8) or 1.9% (8) and recorded continuously during surgery. RESULTS: Bispectral index was significantly less in sedated and anesthetized horses, compared with awake horses. However, BIS was not significantly different between sedated and anesthetized horses. Mean BIS in horses anesthetized at 1.9% isoflurane was significantly greater, compared with horses anesthetized at an end-tidal concentration of 1.4%. Four horses in the 1.4% group moved during surgery, and BIS increased immediately prior to movement in 2 of these horses. CONCLUSIONS AND CLINICAL RELEVANCE: BIS is not a precise indicator of degree of CNS depression in isoflurane-anesthetized horses. Thus, determination of BIS may not be a useful technique for monitoring anesthetic depth in isoflurane-anesthetized horses. 相似文献
978.
Interactions between dietary crude protein and essential amino acid intake on performance in broilers 总被引:1,自引:0,他引:1
1. The effect of diets with increasing concentrations of crude protein at either fixed essential amino acid concentrations or at fixed essential amino acid:dietary crude protein ratios on performance was examined in 1- to 4-week-old male Cobb chicks. Increasing crude protein intakes at constant essential amino acid concentrations was carried out at two dietary energy contents. 2. Increasing crude protein resulted in a linear decrease in feed intake while weight gain and feed efficiency changed quadratically with a smaller positive effect at the highest crude protein intakes. Feed intake decreased and feed efficiency increased with higher dietary energy and interactions between protein and energy were significant. Abdominal fat content and the efficiency of protein retention decreased with increasing dietary protein intake. 3. Using constant essential amino acid:crude protein ratios at increasing crude protein intakes resulted in (Trial 3) feed intake, weight gain and feed efficiency all increasing before reaching a plateau. Abdominal fat decreased with protein intake and the efficiency of protein retention was quadratic, decreasing at the higher protein intakes. 4. Multiple regression analysis of the results of the three trials indicated that partition of energy intake into maintenance, fat-free tissue growth, fat and the energy required to transform protein intake in excess of retention explained more than 98% of variation. 5. It is proposed that broiler performance at the lower protein intakes was limited by either non-essential amino acid (Trials 1 and 2) or essential amino acid (Trial 3) intake whereas at high protein intakes the decreased efficiency of amino acid utilisation after growth requirements are fulfilled resulted in poorer performance. 相似文献
979.
1. A study was conducted to test for the validity of the heterophil/lymphocyte (H/L) ratio as a criterion for selection for resistance to Salmonella typhimurium in chickens. 2. An infective dose of S. typhimurium was given, directly in the crop, to two groups of chicken selected as Resistant (R) and Sensitive (S) on the bases of H/L ratio. The 99% lower confidence limit was used as a borderline; individuals below the limit were considered R and those above S. Many aspects of immune response were compared, namely: H/L ratio, antibody titre, cellular immunity, phagocytic activity, cortisol concentration, bursa and body weight. 3. The R group exceeded the S in all the studied variables of the immune response, indicating the possibility of using the H/L ratio and its confidence limit to select for general resistance. 4. Due to the within-strain variability in resistance, it seems that immunological and genetic studies should take into consideration separation of individuals into R and S before grouping. Failing to do so might lead to erroneous conclusions as a difference may simply be due to the different numbers of R and S included in each group. 相似文献
980.
The spike 1 (S1) surface glycoprotein of infectious bronchitis virus (IBV) is the major inducer of the generation of virus neutralizing antibodies, and the administration of purified S1 has been shown to elicit a protective immune response against virulent virus challenge. On the basis of these observations, recombinant fowl poxvirus (rFPV) containing a cDNA copy of the S1 gene of IBV Mass 41 (rFPV-S1) was constructed and its immunogenicity and vaccine potential were evaluated. Initially, rFPV-S1 was shown to express the S1 in vito by indirect immunofluorescence staining and western blot analyses. Later, in vivo expression was demonstrated by the detection of IBV-specific serum immunoglobulin G and neutralization antibodies in the sera of chickens immunized with rFPV-S1. That the recombinant virus elicited anti-IBV protective immunity was indicated by the manifested, relatively mild clinical signs of disease, decreased titers of recovered challenge virus, and less severe histologic changes of the tracheas in virulent IBV Mass 41-challenged chickens previously receiving rFPV-S1 as compared with parental fowl poxvirus (FPV)-vaccinated control birds. In contrast, chickens immunized with either recombinant or parental FPV were resistant to a subsequent virulent FPV challenge. As to a preferred method of immunization, wing web administration appeared to be superior to the subcutaneous route because a greater percentage of birds vaccinated by the former protocol exhibited an anti-IBV humoral immune response. Thus, rFPV-S1 has potential as a poultry vaccine against both fowl pox and infectious bronchitis. 相似文献