Clinical reappraisal of the composite international diagnostic interview version 3.3 in Qatar's National Mental Health Study.

OBJECTIVES: Lifetime DSM-5 diagnoses generated by the lay-administered Composite International Diagnostic Interview for DSM-5 (CIDI) in the World Mental Health Qatar (WMHQ) study were compared to diagnoses based on blinded clinician-administered reappraisal interviews. METHODS: Telephone follow-up interviews used the non-patient edition of the Structured Clinician Interview for DSM-5 (SCID) oversampling respondents who screened positive for five diagnoses in the CIDI: major depressive episode, mania/hypomania, panic disorder, generalized anxiety disorder, and obsessive-compulsive disorder. Concordance was also examined for a diagnoses of post-traumatic stress disorder based on a short-form versus full version of the PTSD Checklist for DSM-5 (PCL-5). RESULTS: Initial CIDI prevalence estimates differed significantly from the SCID for most diagnoses ( χ 1 2 ${\chi }_{1}^{2}$  = 6.6-31.4, p = 0.010 < 0.001), but recalibration reduced most of these differences and led to consistent increases in individual-level concordance (AU-ROC) from 0.53-0.76 to 0.67-0.81. Recalibration of the short-form PCL-5 removed an initially significant difference in PTSD prevalence with the full PCL-5 (from χ 1 2 ${\chi }_{1}^{2}$  = 610.5, p < 0.001 to χ 1 2 ${\chi }_{1}^{2}$  = 2.5, p = 0.110) while also increasing AU-ROC from 0.76 to 0.81. CONCLUSIONS: Recalibration resulted in valid diagnoses of common mental disorders in the Qatar National Mental Health Survey, but with inflated prevalence estimates for some disorders that need to be considered when interpreting results.

Lubricin/proteoglycan 4 increases in both experimental and naturally occurring equine osteoarthritis.

OBJECTIVE: The goals of this study were (1) to quantify proteoglycan 4 (PRG4) gene expression; (2) to assess lubricin immunostaining; and (3) to measure synovial fluid lubricin concentrations in clinical and experimental models of equine carpal osteoarthritis (OA). DESIGN: Lubricin synovial fluid concentrations and cartilage and synovial membrane PRG4 expression were analyzed in research horses undergoing experimental OA induction (n = 8) and in equine clinical patients with carpal OA (n = 58). Lubricin concentrations were measured using a custom sandwich enzyme-linked immunosorbent assay, and PRG4 expression was quantified using qRT-PCR. Lubricin immunostaining was assessed in synovial membrane and osteochondral sections in the experimental model. RESULTS: Lubricin concentrations increased in synovial fluid following induction of OA, peaking at 21 days post-operatively in OA joints vs sham-operated controls (331 ± 69 µg/mL vs 110 ± 19 µg/mL, P = 0.001). Lubricin concentrations also increased in horses with naturally occurring OA as compared to control joints (152 ± 32 µg/mL vs 68 ± 4 µg/mL, P = 0.003). Synovial membrane PRG4 expression increased nearly 2-fold in naturally occurring OA (P = 0.003), whereas cartilage PRG4 expression decreased 2.5-fold (P = 0.025). Lubricin immunostaining was more pronounced in synovial membrane from OA joints as compared to controls, with intense lubricin localization to sites of cartilage damage. CONCLUSIONS: Although PRG4 gene expression decreases in OA cartilage, synovial membrane PRG4 expression, synovial fluid lubricin concentrations and lubricin immunostaining all increase in an equine OA model. Lubricin may be elevated to protect joints from post-traumatic OA.

Identification of cartilage injury using quantitative multiphoton microscopy.

OBJECTIVE: Cartilage injury can lead to post-traumatic osteoarthritis (PTOA). Immediate post-trauma cellular and structural changes are not widely understood. Furthermore, current cellular-resolution cartilage imaging techniques require sectioning of cartilage and/or use of dyes not suitable for patient imaging. In this study, we used multiphoton microscopy (MPM) data with FDA-approved sodium fluorescein to identify and evaluate the pattern of chondrocyte death after traumatic injury. METHOD: Mature equine distal metacarpal or metatarsal osteochondral blocks (OCBs) were injured by 30 MPa compressive loading delivered over 1 s. Injured and control sites were imaged unfixed and in situ 1 h post-injury with sodium fluorescein using rasterized z-scanning. MPM data was quantified in MATLAB, reconstructed in 3-D, and projected in 2-D to determine the damage pattern. RESULTS: MPM images (600 per sample) were reconstructed and analyzed for cell death. The overall distribution of cell death appeared to cluster into circular (n = 7) or elliptical (n = 4) patterns (p = 0.006). Dead cells were prevalent near cracks in the matrix, with only 26.3% (SE = 5.0%, p < 0.0001) of chondrocytes near cracks being viable. CONCLUSION: This study demonstrates the first application of MPM for evaluating cellular-scale cartilage injury in situ in live tissue, with clinical potential for detecting early cartilage damage. With this technique, we were able to uniquely observe two death patterns resulting from the same compressive loading, which may be related to local variability in matrix structure. These results also demonstrate proof-of-concept MPM diagnostic use in detecting subtle and early cartilage damage not detectable in any other way.

Cryptosporidium parvum: determination of ID50 and the dose-response relationship in experimentally challenged dairy calves.

The objectives were to determine the median infective dose (ID50) of Cryptosporidium parvum and to describe the dose-response relationship including associated clinical illness in experimentally challenged dairy calves. Within the first 24h of life, 27 test calves were experimentally challenged with C. parvum oocysts and 3 control calves were sham dosed. Test calves received 1 of 8 possible doses (25, 50, 100, 500, 1 × 10(3), 1 × 10(4), 1 × 10(5), and 1 × 10(6) oocysts). All 27 test calves developed diarrhea. Fecal oocyst shedding occurred in 25 (92.6%) test calves and in 0 control calves. The 2 non-shedding test calves both received 25 oocysts. There was an inverse relationship between dose and time to onset of fecal oocyst shedding (P=0.005). There was no relationship found between dose and duration (P=0.2) or cessation (P=0.3) of fecal oocyst shedding. In addition, there was not a significant relationship between log-dose and the log-peak oocysts (P=0.2) or log-total oocysts (P=0.5) counted/g of feces across the dose groups. There was a positive dose-response relationship between log-dose and diarrhea (P=0.01). However, when controlling for other factors, such as onset and cessation of fecal oocyst shedding, dose was not a significant predictor of diarrhea (P=0.5). Onset and cessation of fecal oocyst shedding were found to be the best predictors of diarrhea (P=0.0006 and P=0.04, respectively). The ID50 for fecal oocyst shedding was 5.8 oocysts, for diarrhea was 9.7 oocysts, and for fecal oocyst shedding with diarrhea was 16.6 oocysts. Given that the ID50 of C. parvum is far less than would be excreted into the environment by a naturally infected calf, prevention and control of cryptosporidiosis is a formidable challenge.

Evaluation of complications and short-term outcome after unilateral or single-session bilateral tibial tuberosity advancement for cranial cruciate rupture in dogs.

OBJECTIVE: To compare the resulting complications, short-term results, and client satisfaction for treatment of cranial cruciate ligament rupture using either unilateral or bilateral single-session tibial tuberosity advancement (TTA) in dogs. METHODS: Medical records of 68 dogs (101 stifles) undergoing unilateral or bilateral single-session TTA were evaluated. Data gathered included signalment, history, physical examination findings, anaesthesia and surgical time, type of cranial cruciate ligament rupture and meniscal injury, implants, and intra-operative and postoperative complications. A mixed effect logistic regression analysis was performed to determine if complications were grouped by surgical procedure. Linear regression was performed to determine the influence of the variables on the occurrence of complications. Values of p <0.05 were considered significant. RESULTS: No major intra-operative complications occurred. Twenty stifles (20%) developed a complication after surgery (11 minor, 9 major). There was no significant difference in occurrence of complications between dogs undergoing unilateral (n = 8) or bilateral single-session (n = 12) TTA (p = 0.69). The only risk factor found to be associated with complication occurrence was age. CLINICAL SIGNIFICANCE: This is the first report evaluating the use of bilateral simultaneous TTA. There was no significant difference in complication rates between unilateral and bilateral single-session TTA. Additional evaluation is needed to fully determine the extent of complications and long-term outcome of bilateral single-session TTA.

Treatment of subchondral cystic lesions of the medial femoral condyle of mature horses with growth factor enhanced chondrocyte grafts: a retrospective study of 49 cases.

REASONS FOR PERFORMING STUDY: To evaluate the long-term clinical outcome after allogeneic chondrocyte and insulin-like growth factor-I (IGF-I) grafting of subchondral cystic lesions (SCLs) of the femoral condyle in horses. OBJECTIVE: To test the hypothesis that chondrocyte and IGF-I grafts will improve the long-term clinical outcome in arthroscopically debrided SCLs. METHODS: Medical records of 49 horses with SCLs of the femoral condyle treated by debridement and implantation of chondrocytes and IGF-I were reviewed. Preoperative radiographs were obtained, and caudocranial radiographic projections were used to establish a ratio between cyst and femoral condyle size. Arthroscopic cyst debridement followed by filling of the bone void with autologous cancellous bone (45 horses) or tricalcium phosphate granules (4 horses) was performed. A paired syringe containing a fibrinogen and chondrocyte mixture in one syringe and calcium-activated bovine thrombin with IGF-I in the other was used to cover the surface. A successful outcome was defined as a horse that performed to its intended use without lameness. RESULTS: A successful outcome was achieved in 36 of 49 horses (74%). Preoperative radiography was performed in all horses, with 33 horses having unilateral SCLs of the medial femoral condyle, 15 horses having bilateral SCLs of the medial femoral condyle, and one horse having bilateral SCLs of the lateral femoral condyle. Median age of the horses was 3.3 years. Fifteen horses had preoperative radiographic and arthroscopic evidence of osteoarthritis (OA). A successful outcome was not influenced by age of horse, presence of pre-existing osteoarthritis or preoperative size of the subchondral cyst. Grafting resulted in success for 80% of horses >3 years old, and in 80% of horses with OA. CONCLUSIONS: Implantation of allogeneic chondrocytes supplemented with IGF-I is an effective treatment for horses with SCLs of the femoral condyle, and particularly for older horses and horses with pre-existing osteoarthritis. POTENTIAL RELEVANCE: Chondrocyte implantation may offer a greater chance of long-term success in older horses and horses with osteoarthritis than has been previously reported with cyst debridement alone.

A collagenase gel/physical defect model for controlled induction of superficial digital flexor tendonitis.

REASONS FOR PERFORMING STUDY: A consistent and clinically relevant model for the induction of core lesions confined to the mid-metacarpal superficial digital flexor tendon (SDFT) has not been previously reported. Injection of bacterial collagenase is commonly used but often results in large, irregular and inconsistent lesions that disrupt the superficial tendon layers and epitenon. OBJECTIVE: To develop and evaluate a new injection technique for collagenase induction of SDFT injury. METHODS: Collagenase gel was injected into a physical columnar defect created by longitudinally placing a curved 16 gauge 8.89 cm needle in the mid-metacarpal SDFT in a randomly selected forelimb of 10 horses. A placebo treatment injection was performed 1 week later. Serial ultrasound examinations were performed. Horses were subjected to euthanasia at 2 (n = 2), 4 (n = 2), 8 (n = 4) and 16 (n = 2) weeks post treatment injection. Post mortem magnetic resonance imaging and histological analysis were performed. Gene expression (18S, SCX, TNC, TNMD, COL1A1, COL3A1, COMP, DCN, MMP1, MMP3 and MMP13), total DNA, glycosaminoglycan and collagen content were determined for experimental tendons (n = 10) and unaffected tendons (n = 9). RESULTS: Mid-metacarpal SDFT core lesion induction was successful in all tendons with consistent lesion cross-sectional area and minimal epitenon disruption. Histology confirmed loss of normal tendon architecture after tendonitis induction and subsequent healing of the tendon core lesion. Compared with gene expression in unaffected tendons, several tested genes were significantly upregulated (COL1A1, COL3A1, TNMD, SCX, TNC, MMP13), while others showed significant downregulation (COMP, DCN, and MMP3). CONCLUSION: Compared with the previously used direct injection of collagenase, this injection technique was easily performed and induced more consistent lesions that were mid-metacarpal and did not disrupt the epitenon. POTENTIAL RELEVANCE: This model will allow for objective assessment of therapies for tendon regeneration in the mid-metacarpal SDFT prior to clinical trials and routine clinical application.

Arthroscopic reattachment of osteochondritis dissecans cartilage flaps of the femoropatellar joint: long-term results.

REASONS FOR PERFORMING STUDY: Long-term efficacy of arthroscopic cartilage reattachment for the treatment of osteochondritis dissecans (OCD) lesions in the equine femoropatellar joint is unknown. OBJECTIVE: To evaluate radiographic outcome and long-term performance of horses undergoing OCD reattachment. HYPOTHESIS: Separated OCD cartilage flaps may be reincorporated into the joint surface by reattachment rather than flap removal. METHODS: Polydioxanone pins were utilised arthroscopically to reattach OCD lesions in 40 of 44 joints from 27 horses. Cartilage was reattached when it had persisting perimeter continuity, the surface was not deeply fissured or irregular, and the cartilage was not protuberant or extensively mineralised. Bone marrow aspirate concentrate was grafted to additional areas denuded of cartilage or alongside reattached cartilage. RESULTS: Breeds included Thoroughbred (n = 18), Quarter Horse (n = 4), Warmblood (n = 3), Standardbred (n = 1) and Arabian (n = 1). Mean age was 9.7 months. Radiographic lesion length was 1.5-6.3 cm. Reattachment alone was used in 32 of 44 affected joints, a combination of debridement and reattachment in 8 joints and debridement alone in 4 joints. One horse was destroyed due to tendon laceration. Of the remaining 26 horses, mean duration of follow-up was 15.6 months (range 2 months-12 years). Radiographic resolution of OCD lesions treated with reattachment was significantly improved at 6 months. Twenty horses had long-term performance data, of which 19 were sound and had reached intended athletic potential. One horse remained lame, and an additional 6 were sound but remained unbroken or were convalescing. Thus, an overall success rate based upon continued soundness in performing horses was 95% (19/20). CONCLUSION: Cartilage flap reattachment can salvage OCD cartilage by integration with the underlying bone. POTENTIAL RELEVANCE: Extensive OCD cartilage flaps may be salvaged by reattachment which can result in normal radiographic subchondral bone contour and long-term athletic performance.

Factors associated with the risk of West Nile virus among crows in New York State.

West Nile virus (WNV) is transmitted between avian hosts in enzootic cycles by a mosquito vector. The virus has significant disease effects on humans and equines when it bridges into an epizootic cycle. As the initial epidemic of WNV in 1999, perennial outbreaks in New York State suggest the local establishment of natural foci with perpetuation of the virus among susceptible hosts rather than reintroduction of the virus. The factors that play a role in the perpetuation of the virus are not fully understood. American crows (Corvus brachyrhynchos) are known to be highly susceptible to infection with the virus. We investigate the factors that put crows at risk of infection in Tompkins County, New York during the period of 2000-2008 in a case-control study. Cases were crow carcasses that were found dead and tested positive for WNV using real time reverse transcription or VecTest. Data on putative risk factors were collected and assessed for significance of association with the presence of WNV using logistic regression analysis to evaluate the significance of each factor while simultaneously controlling for the effect of others. The risk of a crow carcass testing WNV positive varied with age, season of the year and ecological area where the carcass was found. Crows that were more than 1-year-old were four times more likely to be WNV positive in comparison to birds that were less than 1 year of age. It was three times more likely to find WNV positive carcasses in residential areas in comparison to rural areas. The risk of testing WNV positive did not vary by sex of the crow carcasses.

Relationships between race earnings and horse age, sex, gait, track surface and number of race starts for Thoroughbred and Standardbred racehorses in North America.

REASONS FOR PERFORMING STUDY: There is no consensus on objective outcome measures that can be used to determine if a medical or surgical treatment affects race performance. OBJECTIVE: To determine the association between 2 commonly used outcome measures (total starts and total earnings) and age, sex, gait and race surface. METHODS: A cross-sectional study was performed using the race performance data for all Thoroughbred horses age 2, 3, 4 and 5 years racing in the United States, and Standardbred horses of the same ages racing in the United States and Canada during the year 2006. Median earnings and starts were determined for each combination of age, sex and track surface (for Thoroughbred) or gait (for Standardbred). The effect these variables had on starts on race earnings ($) was determined using linear regression. RESULTS: Race records for 68,649 Thoroughbreds and 25,830 Standardbreds were obtained. All independent variables (age, breed, sex, gait, track surface and total number of starts) had a significant impact on total earnings (P<0.0001). CONCLUSIONS: The data show considerable variation across age groups and track surfaces for Thoroughbreds and across age groups for Standardbreds. They also show that the decision to use earnings or starts as outcome measures could have a marked effect on reported success for a particular treatment. POTENTIAL RELEVANCE: Both earning and start data should be reported in studies evaluating outcome following surgery or other intervention. Considerations of age, breed, sex, track surface and gait should be included in the design of these studies.

The risk of Listeria monocytogenes infection in beef cattle operations.

AIM: To determine the prevalence of Listeria monocytogenes and associated risk factors among beef operations (cow-calf and feedlot) in central and southern California. METHODS AND RESULTS: A repeated cross-sectional study where faecal and environmental samples were collected from 50 operations three times a year at different seasons was carried out. Samples were tested for presence of L. monocytogenes using a combination of enrichment and polymerase chain reaction tests. Data on putative risk factors were also collected. Listeria monocytogenes was detected in faecal samples from cows, calves and other animals on calf-cow operations at proportions of 3.1%, 3.75% and 2.5%, respectively. The organism was detected in 5.3% of cut-grass, 5.3% of soil, 14.3% of irrigation ditches, 3.1% of the ponds and 6.5% of water troughs samples. Listeria monocytogenes was less common in faecal (0.3%) and soil (0.75%) samples collected from feedlots. CONCLUSIONS: Listeria monocytogenes was present at a higher proportion among cow-calf operations than feedlots. There was no significant seasonal variation in the occurrence of this pathogen within the two types of operations. SIGNIFICANCE AND IMPACT OF THE STUDY: If risk mitigation strategies were implemented to reduce the public health risk these should focus in cow-calf operations.

Crib-biting in US horses: breed predispositions and owner perceptions of aetiology.

REASONS FOR PERFORMING STUDY: Crib-biting is an equine stereotype that may result in diseases such as colic. Certain breeds and management factors have been associated. OBJECTIVES: To determine: breed prevalence of crib-biting in US horses; the likelihood that one horse learns to crib-bite from another; and owner perceptions of causal factors. METHODS: An initial postal survey queried the number and breed of crib-biting horses and if a horse began after being exposed to a horse with this habit. In a follow-up survey, a volunteer subset of owners was asked the number of affected and nonaffected horses of each breed and the extent of conspecific contact. The likelihood of crib-biting given breed and extent of contact was quantified using odds ratio (OR) and significance of the association was assessed using the Chi-squared test. RESULTS: Overall prevalence was 4.4%. Thoroughbreds were the breed most affected (133%). Approximately half of owners believed environmental factors predominantly cause the condition (54.4%) and crib-biting is learned by observation (48.8%). However, only 1.0% of horses became affected after being exposed to a crib-biter. The majority (86%) of horses was turned out in the same pasture with other horses and extent of contact with conspecifics was not statistically related to risk. CONCLUSION: This is the first study to report breed prevalence for crib-biting in US horses. Thoroughbreds were the breed more likely to be affected. More owners believed either environmental conditions were a predominant cause or a combination of genetic and environmental factors contributes to the behaviour. Only a small number of horses reportedly began to crib-bite after being exposed to an affected individual, but approximately half of owners considered it to be a learned behaviour; most owners did not isolate affected horses. POTENTIAL RELEVANCE: Genetic predisposition, not just intensive management conditions and surroundings, may be a factor in the high crib-biting prevalence in some breeds, and warrants further investigation. Little evidence exists to suggest horses learn the behaviour from other horses, and isolation may cause unnecessary stress.

Racing performance after combined prosthetic laryngoplasty and ipsilateral ventriculocordectomy or partial arytenoidectomy: 135 Thoroughbred racehorses competing at less than 2400 m (1997-2007).

REASONS FOR PERFORMING STUDY: The success of combined prosthetic laryngoplasty with ipsilateral ventriculocordectomy (LPVC) has not been compared to that of partial arytenoidectomy (PA) in a clinical population. HYPOTHESES: In Thoroughbred (TB) racehorses: (1) earnings after LPVC are unaffected by the severity of recurrent laryngeal neuropathy (RLN) (laryngeal grade III vs. grade IV); (2) LPVC and PA yield similar results in the treatment of grade III RLN; (3) performance outcome following PA is independent of diagnosis (RLN vs. unilateral arytenoid chondritis [UAC]); and (4) neither LPVC nor PA returns horses to the level of performance of controls. METHODS: Medical and racing records of 135 TB racehorses undergoing LPVC or PA for the treatment of grade III or IV RLN or UAC were reviewed. Racing records of age and sex matched controls were also reviewed. RESULTS: After LPVC, horses with grade III RLN performed better compared to those with grade IV RLN. Furthermore, horses treated for grade III RLN by LPVC showed post operative earnings comparable to controls. Rate of return to racing were similar for PA and LPVC, although LPVC resulted in higher post operative earnings. Performance after PA was similar regardless of diagnosis (UAC or RLN). Finally, neither LPVC when performed for grade IV RLN, nor PA performed for either diagnosis restored post operative earnings to control levels. CONCLUSIONS: Thoroughbred racehorses treated by LPVC for grade III RLN show significantly better post operative earnings compared to horses treated for grade IV disease. In grade III RLN, LPVC returns earning potential to control levels. PA and LPVC lead to similar success in terms of rate of return to racing, but PA leads to inferior earnings after surgery. POTENTIAL RELEVANCE: Laryngoplasty should be recommended for all TB racehorses with grade III RLN to maximise return to racing at a high level. This contradicts the common approach of waiting for complete paralysis.

Racing performance following the laryngeal tie-forward procedure: a case-controlled study.

REASONS FOR PERFORMING STUDY: The laryngeal tie-forward procedure (LTFP) is becoming widely used for correction of dorsal displacement of the soft palate (DDSP) despite the absence of an evidence-based assessment of its efficacy. HYPOTHESES: The LTFP returns racing performance to preoperative baseline levels and to that of matched controls; and post operative laryngohyoid position is associated with post operative performance. DESIGN AND POPULATION: Case-controlled study of racehorses undergoing a LTFP for dorsal displacement of the soft palate at Cornell University between October 2002 and June 2007. METHODS: The presence of at least one post operative start and race earnings ($) were used as outcome variables. Controls were matched by age, breed and sex from the third race prior to surgery. A novel radiographic reference system was used to determine laryngohyoid position pre- and post operatively. Data for definitively and presumptively diagnosed cases were analysed separately. RESULTS: During the study interval, 263 racehorses presented, of which 106 were included in the study; 36 had a definitive diagnosis of DDSP and 70 a presumptive diagnosis. Treated horses were equally likely to race post operatively as controls in the equivalent race. Treated horses had significantly lower earnings in the race before surgery than matched controls. The procedure moved the basihyoid bone dorsally and caudally and the larynx dorsally and rostrally. A more dorsal post operative basihyoid position and more dorsal and less rostral laryngeal position were associated with an increased probability of racing post operatively. CONCLUSIONS: Horses undergoing a LTFP are as likely to race post operatively as matched controls. The procedure restores race earnings to preoperative baseline levels and to those of matched controls. POTENTIAL RELEVANCE: This study provides strong evidence supporting the use of the LTFP in racehorses. Further work is needed to determine the relationship between laryngohyoid conformation and nasopharyngeal stability in horses.

Intra-articular stabilisation of the equine cricoarytenoid joint.

REASONS FOR PERFORMING STUDY: The success of laryngoplasty is limited by abduction loss in the early post operative period. OBJECTIVE: To determine the efficacy of polymethylmethacrylate (PMMA) in stabilising the cricoarytenoid joint (CAJ) and reducing the force on the laryngoplasty suture. HYPOTHESIS: Injection into the cricoarytenoid joint resists the forces produced by physiological laryngeal air flows and pressures thereby reducing the force experienced by the laryngoplasty suture. METHODS: Ten cadaver larynges were collected at necropsy and PMMA was injected into one CAJ at selected random. Each larynx was subjected to physiological conditions with with constant (static) or cycling (dynamic) flow. The specimens were tested sequentially in each of 4 conditions: 1) bilateral full abduction (Control 1); 2) transection of the suture on the side without PMMA; 3) bilateral abduction achieved by replacing the suture (Control 2); and 4) cutting the suture on the PMMA side. Tracheal pressure and flow and pressure in the flow chamber were recorded using pressure and flow transducers. The strain experienced by each suture during bilateral abduction (Controls 1 and 2) was measured. Statistical comparison of the 4 conditions was performed using a mixed effect model with Tukey's post hoc test for multiple comparisons. The strain gauge data were analysed by paired comparison of the regression slopes. RESULTS: In the static and dynamic states, tracheal pressure increased and tracheal flow decreased when the suture on the non-cement side was cut (P < 0.05). There was no significant difference in any outcome measure between PMMA injected into the CAJ and bilaterally abducted specimens (Controls 1 and 2) for either condition. The rate of increase in strain with increasing translaryngeal pressure was significantly less on the suture with PMMA placed in the CAJ (P = 0.03). CONCLUSIONS: These data provide strong evidence that injecting PMMA into the CAJ resists the collapsing effect of physiological airflows and pressures in vitro and reduces the force experienced by the laryngoplasty suture during maximal abduction. POTENTIAL RELEVANCE: Augmentation of prosthetic laryngoplasty with this technique may reduce arytenoid abduction loss in the early post operative period.

Risk assessment for Escherichia coli O157:H7 in marketed unpasteurized milk in selected East African countries.

We carried out a study to assess the risk associated with the presence of Shiga toxigenic Escherichia coli (STEC) in informally marketed unpasteurized milk in urban East Africa. Data for the risk models were obtained from on-going and recently completed studies in Kenya and Uganda. Inputs for the model were complemented with data from published literature in similar populations. A fault-tree scenario pathway and modular process risk model approach were used for exposure assessment. Hazard characterization was based on a socioeconomic study with dose-responses derived from the literature. We used a probabilistic approach with Monte Carlo simulation and inputs from farm and household surveys. The qualitative analysis suggested a low to moderate risk of infection from consuming milk and that the widespread consumer practice of boiling milk before consumption was an important risk mitigator. Quantitative analysis revealed that two to three symptomatic STEC infections could be expected for every 10,000 unpasteurized milk portions consumed, with a possible range of 0 to 22 symptomatic cases. Sensitivity analyses to assess the uncertainty and variability associated with the model revealed that the factor with the greatest influence on disease incidence was the prevalence of STEC in dairy cattle. Risk assessment is a potentially useful method for managing food safety in informal markets.

Ocular penetration of intravenously administered enrofloxacin in the horse.

REASON FOR PERFORMING STUDY: Information on antibiotic concentrations in the equine eye following systemic therapy is limited. Reports that Leptospira spp. are frequently present in the eyes of horses with recurrent uveitis, emphasises a need for studies on ocular concentrations of specific antibiotics. HYPOTHESES: 1) Enrofloxacin, administered i.v. at 7.5 mg/kg bwt q. 24 h, results in aqueous humour concentrations greater than the reported minimum inhibitory concentration (MIC) for Leptospira pomona. 2) Aqueous humour paracentesis sufficiently disrupts the blood-aqueous humour barrier (BAB) to cause an increase in aqueous humour protein and enrofloxacin concentrations. METHODS: Aqueous humour enrofloxacin and total protein concentrations were determined in 6 healthy, mature horses after i.v. administration of enrofloxacin. Paracentesis was performed on the left eye on Days 3 and 4, 1 h following enrofloxacin administration, to determine enrofloxacin concentrations in healthy eyes and in eyes with mechanical disruption of the BAB. Paracentesis was also performed on the right eye 23 h after enrofloxacin administration. Blood samples were collected from the horses at identical times to determine enrofloxacin aqueous humour:plasma ratios. RESULTS: Mean +/- s.d. enrofloxacin concentration in the aqueous humour 1 h post administration on Day 3 was 0.32 +/- 0.10 mg/l (range 0.18-0.47); and aqueous humour enrofloxacin, total protein and aqueous humour:plasma enrofloxacin ratios were higher on Day 4 than Day 3. CONCLUSIONS AND POTENTIAL RELEVANCE: Following disruption of the BAB, enrofloxacin concentrations were above the reported MIC for Leptospira pomona.

Plasma adrenocorticotropin, cortisol, and adrenocorticotropin/cortisol ratios in septic and normal-term foals.

BACKGROUND: Little information exists on the hypothalamic-pituitary-adrenal axis in septic foals. HYPOTHESIS: The plasma concentrations of adrenocorticotropin (ACTH) and cortisol are expected to be higher in septic foals as compared to normal foals. The concentrations of hormones in septic foals also are expected to differ further depending upon survival. ANIMALS: Twenty-eight control foals and 46 septic foals <14 days of age were included in this study. METHODS: Blood was collected in EDTA once from 28 normal foals born in the University of Georgia or Cornell University equine research herds and from 46 septic foals within 12 hours after admission to 1 of the 3 tertiary care referral centers involved in the study. Septic foal selection was based on a sepsis score of >11 or a positive blood culture. The control foals were age matched to the septic foals in the study. ACTH and cortisol concentrations were measured by a chemiluminescent immunoassay system. RESULTS: Cortisol concentrations in control foals did not vary with age. Septic foals had significantly higher mean ACTH, cortisol, and ACTH/cortisol ratios than did normal foals. Within the septic foal group, 28 foals survived to discharge, and 18 were euthanized or died. The mean age was not significantly different between the septic surviving and nonsurviving foals. The mean ACTH/cortisol ratio was significantly higher in the septic nonsurviving foals as compared to the septic surviving foals. CONCLUSIONS AND CLINICAL IMPORTANCE: Septic foals had higher hormone concentrations as compared to normal foals, which is an expected endocrine response to critical illness. The increased ACTH/cortisol ratio in nonsurviving septic foals in comparison to surviving septic foals could indicate hypothalamic-pituitary-adrenal axis dysfunction at the level of the adrenal gland in critically ill septic foals.

Racing performance after arthroscopic removal of apical sesamoid fracture fragments in Thoroughbred horses age < 2 years: 151 cases (1989--2002).

REASONS FOR PERFORMING STUDY: Studies on arthroscopic removal of apical proximal sesamoid fracture fragments in Thoroughbred (TB) horses age > or = 2 years have reported a high success rate. However, there are no reports documenting the racing prognosis of TB horses that undergo such surgery as weanlings or yearlings. OBJECTIVES: To describe the incidence of apical proximal sesamoid fractures in immature TB horses, age < 2 years and determine probability and quality of racing performance after arthroscopic removal of such fractures in 151 TB weanlings and yearlings. METHODS: The medical records of TB horses age < 2 years that underwent arthroscopic surgery for removal of apical proximal sesamoid fracture fragments were reviewed. Follow-up information was obtained from race records. Student's t tests were used to compare performance variables of operated racehorses to that of their maternal siblings. RESULTS: Ninety-two percent (139/151) of fractures occurred in the hindlimbs and 8% (11/151) in the forelimbs (fracture of both fore- and hindlimb, n = 1). Horses with forelimb fractures had a greatly reduced probability of racing (55%) compared to those with hindlimb fractures (86%). Overall, 84% of the horses raced post operatively and had performance records similar to that of their maternal siblings, 78% (787/1006) of which raced. CONCLUSIONS: Arthroscopic removal of apical proximal sesamoid fracture fragments in TB weanlings and yearlings carries an excellent prognosis for racing in horses with hindlimb fractures and a reduced prognosis in those with forelimb fractures. Medial fractures of the forelimb carry the worst prognosis. POTENTIAL RELEVANCE: The determination of prognosis increases knowledge on apical sesamoid bone fractures and potential for arthroscopic restoration of the ability to race; and enables the value of yearlings for subsequent sale to be established.

Risk factors associated with Cryptosporidium infection on dairy farms in a New York State watershed.

A cross-sectional study was carried out to determine the prevalence of Cryptosporidium parvum-like oocyst shedding on dairy farms in a watershed in New York State and to identify the factors that put animals at risk. A proportional sample of dairy herds in the targeted area was obtained, and animals were selected using a stratified sampling design to ensure representation of the population at risk. Fecal samples were collected per rectum and analyzed for the presence of C. parvum-like oocysts using the quantitative centrifugation concentration flotation technique and a proprietary enzyme-linked immunoassay. Additionally, isolates of Cryptosporidium were examined via bidirectional DNA sequencing. Data on putative risk factors were collected at the time of sampling and analyzed for association using logistic regression. The herd prevalence was 42% and the overall animal prevalence was 3.2%. The prevalence among animals less than 60 d of age was 20%. The likelihood of shedding Cryptosporidium decreased with the age of the animal and varied with the type of barn water source. Both the number of unweaned calves present at the time of the study, and whether the calves were tied vs. not tied increased the risk of infection. There was significant agreement between the flotation and PCR techniques. Sequencing revealed that 50% of the isolates were Cryptosporidium bovis, an isolate thought to be nonzoonotic.