PubMed Health⌕ Search

Biomedical subjects

A J Roussel

Publications and source records attributed to A J Roussel.

At least 19 recordsLinked to original sources
PubMed2006

Are feeding practices associated with duodenitis-proximal jejunitis?

REASONS FOR PERFORMING STUDY: Feeding concentrate has been putatively associated with risk of development of duodenitis-proximal jejunitis (DPJ); however, this association has not been evaluated systematically in a controlled study. OBJECTIVES: To determine whether there was evidence that feeding practices were associated with increased odds of developing DPJ employing a case control study. HYPOTHESIS: The amount of concentrate fed daily to horses is significantly greater among horses that develop DPJ than control horses with either lameness or other types of colic. METHODS: Feeding practices of cases of DPJ diagnosed between 1997 and 2003 were compared with those of 2 populations of control horses (colic controls and lameness controls) admitted to the clinic from the same time period. Following multiple imputation of missing data, comparisons were made using polytomous logistic regression. RESULTS: Horses with DPJ were fed significantly more concentrate and were significantly more likely to have grazed pasture than either control populations; DPJ horses were significantly more likely to be female than were lameness horses. Results were unchanged after adjusting for bodyweight of the horse. CONCLUSIONS: Feeding and grazing practices differ among horses with DPJ relative to horses with other forms of colic and lame horses. POTENTIAL RELEVANCE: The observed magnitudes of association were not sufficiently strong to merit diagnostic/predictive application; however, these observations, if substantiated by other studies, might provide important aetiological clues.

Animal Feed↗
PubMed2005

Effects of seasonal climatic conditions on the diagnosis of Mycobacterium avium subspecies paratuberculosis in dairy cattle.

Validity of Johne's disease programs and control protocols that rely on established cut points [e.g., specified sample-to-positive (S/P) ratios] for ELISA serological tests depends on interpreted results that are not susceptible to variable test accuracy. It was hypothesized that seasonal variability exists in serological response to Mycobacterium avium subsp. paratuberculosis (MAP) infection. Further, a reciprocal response may occur, resulting in greater risk of fecal shedding in subclinically infected animals. A testing regimen was invoked that included multiple testing of individual adult cows during the 4 seasons. Serum was collected on a cyclic, monthly basis from 3 randomly selected cohorts of dairy cows, and fecal samples were collected from the 20% of cows with the greatest ELISA test S/P ratios. Staggered, quarterly sampling was continued for 1 yr, and at the conclusion, serum was analyzed en masse. The ELISA outcome values (i.e., S/P ratio) were treated both as categorical and continuous variables. The potential lagged effects of temperature-related seasonality on S/P ratio, as well as the potential for a change in test result caused by temperature were assessed. Results for fecal culture were analyzed on a categorical scale and compared with the ELISA results to explore the possibility of reciprocal fecal shedding. No significant seasonal effects on either S/P ratios or the proportion of cows seropositive to MAP were observed. Furthermore, no evidence was found linking temperature-related seasonality to a reciprocal increase in the risk of fecal culture positivity for MAP.

Animals↗
PubMed2004

Meal size and starch content affect gastric emptying in horses.

REASONS FOR PERFORMING STUDY: Feeding practices have been associated with colic in horses. If meal size and composition have an effect on gastric emptying, this could be one of the mechanisms by which feeding practices are related to the occurrence of colic. OBJECTIVES: To evaluate the effect of meal size and starch content on solid phase gastric emptying. METHODS: Solid phase gastric emptying of 3 different radiolabelled meals, small low-starch (SmLS), small high-starch (SmHS) and large high-starch (LgHS) meals, was measured in 5 horses by scintigraphy using 99mTc-disofenin. Data were compared among meals using nonlinear mixed-effects models and paired t tests. RESULTS: On a percentage basis, SmHS emptied significantly faster than LgHS and SmLS emptied significantly faster than SmHS meals. However, when meals of unequal size were compared by emptying rate in g/min and Kcal/min, LgHS emptied significantly faster than SmHS. CONCLUSIONS: Meal size and composition affect gastric emptying. POTENTIAL RELEVANCE: Further work needs to be performed in order to substantiate the possibility of a relationship between digestive functions and occurrence of colic and gastric ulcers.

Animal Feed↗
PubMed2003

Validation of the 13C-octanoic acid breath test for measurement of equine gastric emptying rate of solids using radioscintigraphy.

REASONS FOR PERFORMING STUDY: Disordered gastric motility may be a significant factor in the pathogenesis of many equine conditions. Although tests for liquid phase emptying rate have been validated in the horse, there are no effective tests for solid phase emptying measurement that can be performed routinely in the field. OBJECTIVES: The objective of this study was the assessment of a novel stable isotope technique, the 13C-octane acid breath test (13C-OABT), for the measurement of gastric emptying of solid ingesta, by direct comparison with the optimum method of gastric scintigraphy. METHODS: To facilitate dual measurement of gastric emptying, a test meal was used containing baked egg yolk labelled with both 13C-octanoic acid and 99mtechnetium sulphur colloid. Simultaneous, serial lateral gastric scintigraphs and expiratory breath samples were obtained in 12 healthy horses after voluntary ingestion of the test meal. Analysis of breath 13CO2:12CO2 ratio was performed by continuous flow isotope ratio mass spectrometry. Power regression was used to determine the gastric emptying coefficient, the gastric half-emptying time (t 1/2) and duration of the lag phase (tlag). RESULTS: Significant correlations (P < 0.001) were found between the 2 techniques for measurement of both t 1/2 and tlag. In addition, scintigraphic left t 1/2 was correlated significantly to breath test gastric emptying coefficient (P < 0.001). CONCLUSIONS: It was concluded that the 13C-octanoic acid breath test is a reliable diagnostic procedure to measure gastric emptying rate of solids in the horse. POTENTIAL RELEVANCE: Being safe, noninvasive and easy to perform, this test has potential value as both sensitive diagnostic modality and humane research tool for motility studies.

Animals↗
PubMed2002

The effects of xylazine, detomidine, acepromazine and butorphanol on equine solid phase gastric emptying rate.

The aim of this study was to measure the effects of specific commonly used sedative protocols on equine solid phase gastric emptying rate, using the 13C-octanoic acid breath test (13C-OABT). The gastric emptying of a standard 13C-labelled test meal was measured once weekly in 8 mature horses over two 4 week treatment periods. Each horse acted as its own control. In treatment Period 1, saline (2 ml i.v.), xylazine (0.5 mg/kg i.v.), detomidine (0.01 mg/kg i.v.) or detomidine/butorphanol combination (0.01/0.02 mg/kg i.v.) was administered in randomised order after ingestion of the test meal. During treatment Period 2, test meal consumption was followed by saline, xylazine (1.0 mg/kg i.v.), or detomidine (0.03 mg/kg i.v.) administration, or preceded by acepromazine (0.05 mg/kg i.m.) in randomised order. The 13C:12C ratio of sequential expiratory breath samples was determined by isotope ratio mass spectrometry, and used to measure the gastric half-emptying time, t 1/2, and duration of the lag phase, t lag, for each of the 64 tests. In treatment Period 1, detomidine/butorphanol prolonged both t 1/2 and t lag with respect to xylazine 0.5 mg/kg and the saline control (P < 0.05). In Period 2, detomidine 0.03 mg/kg delayed each parameter with respect to saline, acepromazine and xylazine 1.0 mg/kg (P < 0.001). Xylazine 1.0 mg/kg also lengthened t lag relative to the saline control (P = 0.0004), but did not cause a significant change in t 1/2. Comparison of treatment periods showed that the inhibitory effect of detomidine on gastric emptying rate was dose related (P<0.05). These findings may have clinical significance for case selection when these agents are used for purposes of sedation and/or analgesia.

Acepromazine↗
PubMed2002

Quantitative detection of atropine-delayed gastric emptying in the horse by the 13C-octanoic acid breath test.

The 13C-octanoic acid breath test has been correlated significantly to radioscintigraphy for measurement of gastric emptying indices in healthy horses. The objective of this study was to investigate the validity of the test for measurement of equine delayed gastric emptying, prior to its potential clinical application for this purpose. A model of atropine-induced gastroparesis was used. Gastric emptying rate was measured twice in 8 horses using concurrent radioscintigraphy and/or breath test after treatment i.v. with either atropine (0.035 mg/kg bwt) or saline in randomised order. Analysis of both data sets demonstrated that the atropine treatment had caused a significant delay in gastric emptying rate. Paired breath test data showed an atropine-induced delay in gastric half-emptying time (t 1/2), with no overlap in the 99% CI range (P < 0.001). Significant correlations were found between scintigraphy and 13C-octanoic acid breath test for calculation of both t 1/2 (P < 0.01) and lag phase duration (P < 0.05) in the atropine-delayed emptying results. The mean (s.d.) bias in breath test t 1/2 when compared with scintigraphy was 1.78 (0.58) h. The results demonstrated that the 13C-octanoic acid breath test was an effective diagnostic modality for the measurement of equine delayed gastric emptying. The technique offers advantages to existing methods for clinical investigation, as it is noninvasive, not radioactive, quantitative and requires minimal equipment or training to perform.

Animals↗
PubMed2001

Bacterial microflora of normal and telangiectatic livers in cattle.

OBJECTIVE: To identify potential bacterial pathogens in normal and telangiectatic livers of mature cattle at slaughter and to identify consumer risk associated with hepatic telangiectasia. SAMPLE POPULATION: 50 normal livers and 50 severely telangiectatic livers. PROCEDURE: Normal and telangiectatic livers were collected at slaughter for aerobic and anaerobic bacterial culture. Isolates were identified, and patterns of isolation were analyzed. Histologic examination of all livers was performed. RESULTS: Human pathogens isolated from normal and telangiectatic livers included Escherichia coli O157:H7 and group-D streptococci. Most livers in both groups contained bacteria in low numbers; however, more normal livers yielded negative culture results. More group-D streptococci were isolated from the right lobes of telangiectatic livers than from the left lobes, and more gram-negative anaerobic bacteria were isolated from left lobes of telangiectatic livers than from right lobes. All telangiectatic lesions were free of fibrosis, active necrotizing processes, and inflammation. CONCLUSIONS AND CLINICAL RELEVANCE: The USDA regulation condemning telangiectatic livers is justified insofar as these livers contain more bacteria than normal livers do; however, normal livers contain similar species of microflora. Development of telangiectasia could not be linked to an infectious process. The finding of E coli O157:H7 in bovine livers suggests that information regarding bacterial content of other offal and muscle may identify sources of this and other potential foodborne pathogens and assist in establishing critical control points for the meat industry.

Animals↗
PubMed2001

Risk factors associated with development of postoperative ileus in horses.

OBJECTIVE: To determine risk factors associated with development of postoperative ileus in horses undergoing surgery for colic. DESIGN: Case-control study. ANIMALS: 69 horses that developed ileus after surgery for colic and 307 horses that did not develop postoperative ileus. PROCEDURE: Signalment, history, clinicopathologic data, treatment, lesions, and outcome were obtained from medical records. RESULTS: Variables associated with increased risk of postoperative ileus included age > 10 years, Arabian breed, PCV > or = 45%, high serum concentrations of protein and albumin, anesthesia > 2.5 hours' duration, surgery > 2 hours' duration, resection and anastomosis, and lesions in the small intestine. Enterotomy reduced the risk of postoperative ileus. After multivariate logistic regression, the final model included the variables Arabian breed, PCV > or = 45%, lesion type, duration of surgery (> 2 hours vs < or = 2 hours), and pelvic flexure enterotomy. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that by evaluating certain factors, horses at increased risk of postoperative ileus may be recognized before the condition develops. Preventative treatment and early intervention may be instituted in these horses. Shortening surgery time and performing an enterotomy may decrease the probability of horses developing postoperative ileus.

Age Factors↗
PubMed2000

Abomasal displacement and volvulus in beef cattle: 19 cases (1988-1998).

OBJECTIVE: To assess signalment, history, results of clinical and laboratory testing, and outcome for beef cattle with a left displaced abomasum (LDA), right displaced abomasum (RDA), or abomasal volvulus (AV). DESIGN: Retrospective study. ANIMALS: 19 beef cattle with an AV, LDA, or RDA. PROCEDURE: Signalment; history; results of physical examination, diagnostic testing, and surgical exploration; and condition of the animal at discharge were obtained from medical records. RESULTS: Fourteen cattle had an AV, 4 had an RDA, and 1 had an LDA. Duration of clinical signs ranged from 1 to 21 days. Eighteen cattle had an AV or RDA; 7 were Brahmans, 12 were males, and median age was 10 months. Abdominal distention was observed in 11 cattle, heart rate of > or = 100 beats/minute was detected in 14, and the abomasum was palpable per rectum in all cattle in which per rectal examination was performed. Leukocytosis, neutrophilia, hyperglycemia, azotemia, hypochloremia, and hypokalemia were common laboratory findings. At surgery, 3 cattle with an AV or RDA had a ruptured abomasum. Of the remaining 15 cattle, 12 survived. CONCLUSIONS: Clinical course in beef cattle with an AV or RDA was more protracted than that typically associated with these conditions in dairy cattle, but survival rate in beef cattle that did not have rupture of the abomasum was similar to that of dairy cattle. CLINICAL RELEVANCE: Abomasal displacement should be considered for beef cattle with abdominal distention. Prognostic indicators recommended for use in dairy cattle may not be useful for beef cattle.

Abomasum↗
PubMed2000

Effect of monensin sodium on histological lesions of naturally occurring bovine paratuberculosis.

Of 19 adult cows naturally infected with paratuberculosis, 13 were treated with monensin sodium and six remained untreated. At the beginning of the study, the severity of the histological lesions was assessed from biopsy samples of ileum, liver, mesenteric lymph node and rectal mucosa. From the data acquired it was possible to assign the animals so that the lesions in the two groups were similar (P=0. 8323). Monensin was administered in the feed, which contained 147.5 mg/kg, and each treated cow received 450 mg of monensin daily for 120 days. At the end of this period all cows were killed and histopathological findings in the ileum, liver, mesenteric lymph node and rectal mucosa were compared with the initial findings. A scoring system showed that monensin had a beneficial effect in the ileum (P=0.077), liver (P=0.0322) and rectal mucosa (P=0.0578), but under the conditions of the experiment no such effect could be demonstrated in mesenteric lymph node (P=0.3599). There appeared to be an overall effect on all tissues taken together (P=0.1335). The effect of monensin may have been due to both a halting and a reversal of the pathological process. In all but one of the six untreated cows, the lesions worsened during the course of the experiment.

Animals↗
PubMed2000

Comparison of nuclear scintigraphy and acetaminophen absorption as a means of studying gastric emptying in horses.

OBJECTIVE: To evaluate the correlation between halftime of liquid-phase gastric emptying (T50), determined with nuclear scintigraphy using technetium Tc 99m pentetate, and absorption variables of orally administered acetaminophen. ANIMALS: 6 mature horses. PROCEDURE: Technetium Tc 99m pentetate (10 mCi) and acetaminophen (20 mg/kg of body weight) were administered simultaneously in 200 ml of water. Serial left and right lateral images of the stomach region were obtained with a gamma camera, and T50 determined separately for counts obtained from the left side, the right side and the geometric mean. Power exponential curves were used for estimation of T50 and modified R2 values for estimation of goodness of fit of the data. Serial serum samples were taken, and acetaminophen concentration was determined, using fluorescence polarization immunoassay. Maximum serum concentration (Cmax), time to reach maximum serum concentration (Tmax), area under the curve for 240 minutes and the absorption constant (Ka) were determined, using a parameter estimation program. Correlations were calculated, using the Spearman rank correlation coefficient. RESULTS: Correlations between T50 and Tmax and between T50 and Ka were significant. CONCLUSIONS AND CLINICAL RELEVANCE: Tmax and Ka are valuable variables in the assessment of liquid-phase gastric emptying using acetaminophen absorption. Acetaminophen absorption may be a valuable alternative to nuclear scintigraphy in the determination of gastric emptying rates in equine patients with normally functioning small intestine.

Acetaminophen↗
PubMed2000

Prokinetic effects of erythromycin on the ileum, cecum, and pelvic flexure of horses during the postoperative period.

OBJECTIVE: To evaluate the effect of erythromycin on motility of the ileum, cecum, and pelvic flexure of horses during the postoperative and post-recovery periods. ANIMALS: 8 healthy adult horses. PROCEDURE: Horses were anesthetized and bipolar electrodes were implanted in smooth muscle of the ileum, cecum, and pelvic flexure. Approximately 4, 16, and 24 hours (postoperative recording sessions) and at least 8 days (post-recovery recording session) after surgery, myoelectric activity was recorded before and after administration of erythromycin (0.5 mg/kg). RESULTS: Following erythromycin administration, myoelectric activity was increased in the ileum during all postoperative recording sessions but not during the post-recovery recording session. Myoelectric activity was increased in the cecum following erythromycin administration only during the post-recovery recording session. Myoelectric activity was increased in the pelvic flexure following erythromycin administration during all recording sessions. During several recording sessions, there were short periods during which myoelectric activity was significantly decreased following erythromycin administration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that erythromycin has an effect on myoelectric activity of the ileum, cecum, and pelvic flexure in horses; however, prokinetic effects of erythromycin administered during the postoperative period were not always the same as effects obtained when the drug was administered after horses had recovered from the effects of surgical implantation of recording devices. Therefore, caution must be exercised when extrapolating results of prokinetic studies in healthy animals to animals with abnormal gastrointestinal tract motility.

Animals↗
PubMed1999

Clinical and pathologic features of cloned transgenic calves and fetuses (13 case studies).

The neonatal abnormalities, treatments and outcomes in a group of 13 cloned transgenic calves and fetuses that progressed into the third trimester of pregnancy are described. From these 13 fetuses, 8 calves were born live, 4 stillborn fetuses were recovered from 3 cows that died 7 d to 2 mo before term, and 1 aborted fetus was recovered at 8 mo gestation. All fetuses and calves were derived from the same male fetal Holstein fibroblast cell line transfected with a beta-galactosidase marker gene. Six calves were delivered by Cesarian section and two by vaginal delivery between 278 and 288 d of gestation. Birth weights ranged from 44 to 58.6 kg. Five of the 8 live born calves were judged to be normal within 4 h of birth based on clinical signs and blood gas measurements. One of these 5 calves died at 6 wk of age from a suspected dilated cardiomyopathy. Three of the 8 calves were diagnosed with neonatal respiratory distress immediately following birth, one of which died (at 4 d of age) as a result of pulmonary surfactant deficiency coupled with pulmonary hypertension and elevated systemic venous pressures. Similar findings of chronic pulmonary hypertension were also observed in 2 of 5 fetuses. Placental edema was present in both calves that later died and in the 2 fetuses with cardiopulmonary abnormalities. Hydrallantois occurred with or without placental edema in 6 cows, and only 1 calf from this group survived. The 6 cows without hydrallantois or placental edema produced 5 live calves and 1 aborted fetus. The cardiopulmonary abnormalities observed in the calves and fetuses occurred in utero in conjunction with placental abnormalities, and it is likely that the cloning technique and/or in vitro embryo culture conditions contributed to these abnormalities, although the mechanism remains to be determined.

Animals↗
PubMed1999

Fluid therapy in mature cattle.

Fluid therapy is practical and beneficial when properly administered to cattle. Mature cattle are more frequently alkalotic than acidotic, so nonalkalizing solutions are usually indicated. Exceptions include cattle with choke, carbohydrate engorgement, diabetes mellitus, and occasionally, renal disease, diarrhea, and fatty liver/ketosis. Many dehydrated cattle need supplemental potassium and calcium as well as sodium, chloride, and water. Intravenous administration is indicated in patients with obstructive gastrointestinal disease and those with severe dehydration. Oral or intraruminal administration is less expensive and, often, very effective.

Acidosis↗
PubMed1998

Alterations in acid-base balance and serum electrolyte concentrations in cattle: 632 cases (1984-1994).

OBJECTIVE: To determine typical alterations in acid-base balance and serum electrolyte concentrations in cattle grouped on the basis of age, breed type, hydration status, clinical signs, and underlying disease. DESIGN: Retrospective study. ANIMALS: 632 cattle. PROCEDURE: Information on blood pH, PVO2, PVCO2, HCO3-concentration, and base excess (BE) as well as serum or plasma sodium, potassium, chloride, and total carbon dioxide concentrations was obtained. Values for calves (ie, cattle < 1 month old) were compared with values for cattle > or = 1 month old. Within each age-group, values were compared for cattle grouped on the basis of breed type, previous treatment, and hydration status. Proportions of cattle with various disorders for which values were within, greater than, or less than reference ranges were determined. RESULTS: BE, pH, and HCO3- concentration were significantly higher and PVCO2 and sodium, potassium, and chloride concentrations were significantly lower among cattle > or = 1 month old than calves. Base excess and HCO3- concentration were significantly lower among dairy than beef calves. Sodium and potassium concentrations were significantly lower among dairy than beef cattle > or = 1 month old. A higher proportion of cattle that did not survive had a high anion gap than cattle that did survive. Sodium, potassium, and chloride concentrations were significantly lower among dehydrated cattle than cattle that were not dehydrated. CLINICAL IMPLICATIONS: Because certain alterations were consistently found in some groups of cattle, it may be possible to make reasonable predictions of alterations in acid-base balance and serum electrolyte concentrations when laboratory evaluations are not available.

Acid-Base Equilibrium↗
PubMed1997

Tension band plating of an olecranon fracture in a bull.

A 1,018-kg (2,240-lb), 6-year-old bull was admitted for evaluation of a left forelimb lameness of 7 days' duration. Radiographic views of the proximal portion of the left forelimb revealed a type-III olecranon fracture that was minimally displaced. Conservative treatment, including stall confinement and administration of anti-inflammatory drugs, was attempted. Subsequent radiographic views, 27 days later, revealed displacement of the fracture with minimal callus formation. Open reduction and internal fixation was performed by placing a 4.5-mm, 10-hole broad dynamic-compression on the caudal surface of the olecranon. Good anatomic reduction was achieved, returning the bull to full weightbearing. Eight months following surgery the owners reported the bull was sound at a walk and able to breed cows.

Animals↗
PubMed1997

Immunization with Babesia bigemina rhoptry-associated protein 1 induces a type 1 cytokine response.

Rhoptry-associated protein-1 (RAP-1) homologues of Babesia bigemina and Babesia bovis are promising candidates for inclusion in subunit vaccines against these hemoprotozoan parasites. Partial protection against challenge infection has been achieved with native forms of these antigens, but the mechanism of immunity has not been thoroughly defined. We previously demonstrated that a panel of antigen-specific T helper cell clones derived from B. bigemina RAP-1-immunized cattle expressed relatively high levels of interferon-gamma (IFN-gamma) protein and transcript and low levels of interleukin-4 (IL-4), indicative of a type 1 immune response. In the current study we present evidence that subcutaneous immunization with native B. bigemina RAP-1 protein in RIBI adjuvant induces a predominant type 1 immune response in vivo, characterized by relatively high levels of IFN-gamma and IL-2 and low levels of IL-4 and IL-10 mRNA in the draining prescapular lymph node. Ex vivo restimulation of draining lymph node lymphocytes with specific antigen resulted in proliferation and enhanced expression of IL-2 and IFN-gamma, whereas IL-4 and IL-10 transcript levels remained relatively low. These findings show that our previously described cytokine profiles of antigen-specific cloned T cell lines are representative of autologous in vivo responses and confirm that type 1 recall responses to B. bigemina RAP-1 can be evoked in immunized animals by native parasite antigen.

Animals↗