Prevalence of scrapie in sheep in Great Britain estimated from abattoir surveys during 2002 and 2003     

Elliott H  Gubbins S  Ryan J  Ryder S  Tongue S  Watkins G  Wilesmith J 《The Veterinary record》2005,157(14):418-419

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Survey of cardiac arrhythmias during submaximal and maximal exercise in Thoroughbred racehorses     

Ryan N  Marr CM  McGladdery AJ 《Equine veterinary journal》2005,37(3):265-268

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Pharmacokinetics and pharmacodynamics of pantoprazole in clinically normal neonatal foals     

Ryan CA  Sanchez LC  Giguère S  Vickroy T 《Equine veterinary journal》2005,37(4):336-341

REASONS FOR PERFORMING STUDY: Proton pump inhibitors (PPIs) are a mainstay of treatment for acid-related ulceration in man and horses. Currently, only an oral preparation of omeprazole is approved for use in horses in the USA. Intravenous administration of a PPI would provide a useful therapeutic alternative for those foals in which oral medication is not feasible. OBJECTIVE: To investigate the pharmacokinetics and pharmacodynamics of pantoprazole following i.v. or intragastric administration in healthy neonatal foals. METHODS: Seven healthy foals age 6-12 days at the start of the study were evaluated. Treatments included no drug administration, i.v. pantoprazole (1.5 mg/kg bwt) and intragastric pantoprazole (1.5 mg/kg bwt). Intragastric pH was recorded for 24 h after drug administration for pharmacodynamic evaluation. Plasma pantoprazole concentrations were measured using high-performance liquid chromatography. RESULTS: Plasma concentrations of pantoprazole were detectable at the 5 min sampling point following i.v. or intragastric administration. Bioavailability of intragastric-administered pantoprazole was 41%. Baseline mean hourly pH was 1.5-6.1. There was a statistically significant increase in mean hourly pH relative to untreated foals 2-24 h after i.v. or intragastric pantoprazole administration. CONCLUSIONS: Based on these data, i.v. or intragastric administration of pantoprazole results in a significant, prolonged increase in intragastric pH. POTENTIAL RELEVANCE: The i.v. formulation of pantoprazole may provide a clinically useful alternative means of acid suppression in foals unable to tolerate enteral administration of a PPI, such as those with pyloric outflow obstruction.  相似文献   

Ulceration in the proximal portion of the urethra as a cause of hematuria in horses: four cases (1978-1985)     

K C Lloyd  J D Wheat  A M Ryan  M Matthews 《Journal of the American Veterinary Medical Association》1989,194(9):1324-1326

Sudden onset of hematuria was associated with mucosal ulceration of the proximal portion of the urethra in 1 stallion and 3 geldings. Hematuria was observed characteristically and consistently at the end of urination. Mucosal ulceration was identified endoscopically in the proximal portion of the urethra at the level of the ischial arch. Biopsy of an ulcerated area of the proximal urethra in one gelding revealed transitional cell carcinoma. Treatment regimens varied from systemic antimicrobial and/or vasoactive therapy to diversion of urinary flow via a temporary perineal urethrostomy. Hematuria resolved in 14 to 24 days (average, 20 days) after treatment was begun, except in one gelding that died of undetermined causes during an initial examination. In the 3 remaining horses, hematuria had not recurred for up to 9 years (average, 1 year).  相似文献   

Bovine spongiform encephalopathy: case-control studies of calf feeding practices and meat and bonemeal inclusion in proprietary concentrates     

J.W. Wilesmith  J.B.M. Ryan  W.D. Hueston 《Research in veterinary science》1992,52(3):459-331

Following the identification of meat and bonemeal as the most likely source of exposure for the occurrence of bovine spongiform encephalopathy (BSE) in Great Britain case-control studies were initiated to investigate this hypothesis. These involved a comparison of the consumption of specific proprietary calf feedstuffs, and whether or not meat and bonemeal had been included, between animals born in 1983-84 in BSE-unaffected herds and confirmed cases of BSE also born in 1983-84. The feeding of proprietary concentrates containing meat and bonemeal was found to be a statistically significant risk factor for the occurrence of BSE. These studies therefore support the initial hypothesis that BSE occurred as a result of exposure to a scrapie-like agent via meat and bonemeal.  相似文献   

Effects of short-term early gestational exposure to endophyte-infected tall fescue diets on plasma 3,4-dihydroxyphenyl acetic acid and fetal development in mares     

Youngblood RC  Filipov NM  Rude BJ  Christiansen DL  Hopper RM  Gerard PD  Hill NS  Fitzgerald BP  Ryan PL 《Journal of animal science》2004,82(10):2919-2929

Consumption of wild-type (toxic) endophyte-infected tall fescue (E+) by horses during late gestation is known to adversely affect pregnancy outcome; however, little is known of the potential disruptive consequences of E+ consumption by mares during the critical phases of placentation and fetal development in early pregnancy. The objective of this study was to evaluate the detrimental effects of feeding E+ to mares during early gestation. Mares (n = 12) paired by stage of gestation (d 65 to 100) were assigned to diets (six per diet) consisting of endophyte-free (E-) or E+ tall fescue seed (50% E- or E+ tall fescue seed, 45% sweet feed, and 10% molasses fed at 1.0% of BW/d). Mares also had ad libitum access to E+ or E- annual ryegrass hay, and were fed diets for 10 d. Following removal from the tall fescue diet on d 11, mares were placed on common bermudagrass pasture and monitored until d 21. Morning and evening rectal temperatures were recorded and daily blood samples were collected for progesterone and prolactin (PRL) analyses, whereas samples for 3,4-dihydroxyphenyl acetic acid (a catecholamine metabolite) analysis were collected on alternate days. For clinical chemistry analysis, blood samples were collected on d 0, 5, 10 and 21. Daily urine samples were collected for ergot alkaloid analysis, and ultrasonography was performed for presence of echogenic material in fetal fluids. Rectal temperatures (E+ 37.76+/-0.03; E- 37.84+/-0.03 degrees C) and serum PRL concentrations (E+ 14.06< or =0.76; E- 12.11+/-0.76 ng/mL) did not differ (P = 0.96) between treatments. Measuring the change in basal serum concentration from d 0 over time, progesterone concentrations did not differ (-0.64 +/-1.49 and -0.55+/-1.47 ng/mL for E+ and E- mares, respectively). There was no negative pregnancy outcome, and ultrasonography indicated no increase in echogenic material in fetal fluids. Plasma 3,4-dihydroxyphenyl acetic acid concentrations decreased (P < 0.05) in E+ compared with E- mares (2.1+/-0.14 and 4.4+/0.43 ng/mL, respectively). Urinary ergot alkaloid concentration was greater (P < 0.01) in mares consuming E+ compared with E- (532.12+/- 52.51 and 13.36+/-2.67 ng/mg of creatinine, respectively). Although no fetal loss was observed during the current study, elevated concentrations of urinary ergot alkaloid were consistent with depressed endogenous catecholamine activity, suggestive of an endocrine disruptive effect of hypothalamic origin.  相似文献   

Conservation of RET regulatory function from human to zebrafish without sequence similarity     

Fisher S  Grice EA  Vinton RM  Bessling SL  McCallion AS 《Science (New York, N.Y.)》2006,312(5771):276-279

Evolutionary sequence conservation is an accepted criterion to identify noncoding regulatory sequences. We have used a transposon-based transgenic assay in zebrafish to evaluate noncoding sequences at the zebrafish ret locus, conserved among teleosts, and at the human RET locus, conserved among mammals. Most teleost sequences directed ret-specific reporter gene expression, with many displaying overlapping regulatory control. The majority of human RET noncoding sequences also directed ret-specific expression in zebrafish. Thus, vast amounts of functional sequence information may exist that would not be detected by sequence similarity approaches.  相似文献   

Experimental infection of Attwater's/greater prairie chicken hybrids with the reticuloendotheliosis virus     

Bohls RL  Collisson EW  Gross SL  Silvy NJ  Phalen DN 《Avian diseases》2006,50(4):613-619

Reticuloendotheliosis virus (REV), a common pathogen of poultry, has been associated with runting and neoplasia in an endangered subspecies of grouse, the Attwater's prairie chicken. The pathogenesis of REV infection was examined in experimentally infected prairie chickens. Three groups of four Attwater's/greater prairie chicken hybrids were infected intravenously with varying doses (tissue culture infective dose [TCID50], 200, 1000, and 5000) of a prairie chicken-isolated REV. A fourth group of four birds was not infected. Blood was collected prior to infection, and at various times up to 37 wk following infection. Peripheral blood mononuclear cells were examined for integrated proviral DNA by a single-amplification polymerase chain reaction (PCR) and nested PCR of a region within the pol gene. The nested PCR identified REV proviral DNA in all REV-inoculated birds by 2 wk postinfection and confirmed chronic infection throughout the study. With the exception of a bird that died from bacterial pneumonia 8 wk postinfection, neoplasia, resembling that seen in naturally occurring infections, was observed in all birds, even those receiving as little as 200 TCID50 of virus.  相似文献   

Use of intra-articular administration of ethyl alcohol for arthrodesis of the tarsometatarsal joint in healthy horses     

Shoemaker RW  Allen AL  Richardson CE  Wilson DG 《American journal of veterinary research》2006,67(5):850-857

OBJECTIVE: To evaluate the efficacy and safety of intra-articular administration of ethyl alcohol for arthrodesis of tarsometatarsal joints in horses. ANIMALS: 8 healthy female horses without lameness or radiographic evidence of tarsal joint osteoarthritis. PROCEDURE: In each horse, 1 tarsometatarsal joint was treated with 4 mL of 70% ethyl alcohol and the opposite joint was treated with 4 mL of 95% ethyl alcohol. Lameness examinations were performed daily for 2 weeks, followed by monthly evaluations for the duration of the 12-month study. Radiographic evaluations of both tarsi were performed 1 month after injection and every 3 months thereafter. Gross and histologic examinations of the tarsi were undertaken at completion of the study. RESULTS: Horses had minimal to no lameness associated with the treatments. Radiography revealed that 8 of 16 joints were fused by 4 months after treatment, with significantly more joints fused in the 70% ethyl alcohol group. Fifteen of 16 joints were considered fused at postmortem examination at 12 months. Gross and histologic examinations revealed foci of dense mature osteonal bone spanning the joint spaces. Bony fusion appeared to be concentrated on the dorsolateral, centrolateral, and plantarolateral aspects of the joints. Significant differences were not detected between treatment groups for lameness or pathologic findings. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of ethyl alcohol into the tarsometatarsal joint of healthy horses appeared to facilitate arthrodesis of the joint in a pain-free manner. Results warrant further investigation into the potential use of ethyl alcohol in horses clinically affected with osteoarthritis of the tarsometatarsal and distal intertarsal joints.  相似文献   

Effects of dobutamine, norepinephrine, and vasopressin on cardiovascular function in anesthetized neonatal foals with induced hypotension     

Valverde A  Giguère S  Sanchez LC  Shih A  Ryan C 《American journal of veterinary research》2006,67(10):1730-1737

OBJECTIVE: To determine the effects of dobutamine, norepinephrine, and vasopressin on cardiovascular function and gastric mucosal perfusion in anesthetized foals during isoflurane-induced hypotension. ANIMALS: 6 foals that were 1 to 5 days of age. PROCEDURES: 6 foals received 3 vasoactive drugs with at least 24 hours between treatments. Treatments consisted of dobutamine (4 and 8 Sang/kg/min), norepinephrine (0.3 and 1.0 Sang/kg/min), and vasopressin (0.3 and 1.0 mU/kg/min) administered IV. Foals were maintained at a steady hypotensive state induced by a deep level of isoflurane anesthesia for 30 minutes, and baseline cardiorespiratory variables were recorded. Vasoactive drugs were administered at the low infusion rate for 15 minutes, and cardiorespiratory variables were recorded. Drugs were then administered at the high infusion rate for 15 minutes, and cardiorespiratory variables were recorded a third time. Gastric mucosal perfusion was measured by tonometry at the same time points. RESULTS: Dobutamine and norepinephrine administration improved cardiac index. Vascular resistance was increased by norepinephrine and vasopressin administration but decreased by dobutamine at the high infusion rate. Blood pressure was increased by all treatments but was significantly higher during the high infusion rate of norepinephrine. Oxygen delivery was significantly increased by norepinephrine and dobutamine administration; O2 consumption decreased with dobutamine. The O2 extraction ratio was decreased following norepinephrine and dobutamine treatments. The gastric to arterial CO2 gap was significantly increased during administration of vasopressin at the high infusion rate. CONCLUSION AND CLINICAL RELEVANCE: Norepinephrine and dobutamine are better alternatives than vasopressin for restoring cardiovascular function and maintaining splanchnic circulation during isoflurane-induced hypotension in neonatal foals.  相似文献