Effect of racing on cardiac troponin I concentration and associations with cardiac rhythm disturbances in Standardbred racehorses.

INTRODUCTION/OBJECTIVES: Accumulating evidence indicates intense exercise can be associated with myocardial damage. Investigating the impact of maximal effort on myocardium and exploring possible association of injury with rhythm disturbance requires a high-sensitivity cardiac troponin assay. The objectives of this study were: (1) to determine the effect of racing on serum cardiac troponin I (cTnI) in Standardbred horses using a high-sensitivity assay; (2) to determine the 99th percentile of cTnI in healthy horses and investigate the effect of demographic variables on cTnI prevailing pre-race in Standardbred horses using a validated high-sensitivity assay and a contemporary assay, and; (3) to explore associations between exercise-associated arrhythmia and cTnI concentration. ANIMALS: Racehorses (n = 145). MATERIALS AND METHODS: ≤ 2 h pre-race, cTnI concentrations were measured in 158 race starts. Electrocardiogram (ECG) monitoring was applied during racing and race recovery and screened for complex ventricular arrhythmia. Associations between cTnI prevailing before racing concentration, age, sex, and gait were investigated. Demographic and performance variables were evaluated for associations with cTnI concentration post-race and rhythm disturbance. RESULTS: Incidence of arrhythmia was 11.6% (16 horses). A significant increase in median (interquartile range) cTnI concentration of 1.36 (0.49-2.81) ng/L was found post-race (p < 0.0001). Serum cardiac troponin I (cTnI) concentration prevailing pre-race was positively associated with increasing age, and gait. Serum cardiac troponin I prevailing post-race was positively associated with concentration prevailing pre-race. Interaction between arrhythmia and finishing distanced revealed horses finishing distanced and experiencing arrhythmia displayed higher cTnI release than with the presence of either alone. CONCLUSIONS: Racing increased cTnI concentration. Horses finishing distanced and also exhibiting arrhythmia may be experiencing myocardial compromise.

Risk factors for duration of equine rhinitis A virus respiratory disease.

BACKGROUND: Infectious respiratory disease is common in young horses and can impact athletic performance and long-term health. Significant variation in the duration of clinical disease has been observed, even in the absence of secondary complications. The determination of factors associated with disease chronicity may facilitate clinical decision-making and the development of improved biosecurity protocols. OBJECTIVE: To investigate contact network characteristics, and demographic variables associated with time to clinical recovery from Equine Rhinitis A virus respiratory disease. STUDY DESIGN: Prospective cohort study. METHODS: Yearling Standardbred racehorses (n = 58) housed in a multi-barn training facility in Southern Ontario were included. Horses were monitored daily for clinical signs of acute respiratory disease over a 41-day period in Autumn 2017. Contact patterns between horses, including older racehorses, were determined through use of proximity loggers attached to halters during the initial 7-day of the study. Associations between duration of disease, demographic factors (birth month, gait, sex and yearling sale), serologic titres and network metrics (degree, betweenness and Eigenvector centrality) were investigated using a Cox proportional hazard model. RESULTS: Yearling attack rate for infectious respiratory disease was 87.9% (n = 51). Median time to recovery was 6 days (IQR = 1-32) and 17 horses were censored due to early withdrawal or failure to recover during the study period. In those yearlings born February-May, birth month was significant in the Cox proportional hazard model (Hazard Ratio 0.7, 95% CI 0.49-1, P = 0.05). MAIN LIMITATION: Probability of censoring was not independent of outcome which necessitated use of sensitivity analysis. CONCLUSIONS: These findings suggest late born foals are less likely to recover quickly from infectious respiratory disease.

Post-exercise cardiac troponin I release and clearance in normal Standardbred racehorses.

BACKGROUND: There are currently no studies detailing cardiac troponin I (cTnI) release in normal horses post-exercise using an analytically validated assay. These data are essential for selecting appropriate sampling times in equine athletes with suspected myocardial injury. OBJECTIVE: To plot the magnitude and time course of cTnI release after maximal effort, using validated cTnI assays. STUDY DESIGN: Descriptive longitudinal study. METHODS: Five clinically normal Standardbred racehorses in race training were included in the study. Horses were exercised in harness at near-race intensity. Blood samples were taken immediately pre- and post-exercise and then hourly for 24 h. Samples were analysed using the validated high-sensitivity cTnI assay and a contemporary sensitivity cTnI assay. RESULTS: Mean resting cTnI was 1.33 ± 0.6 s.d. ng/L (range, 0.82-2.33 ng/L) using assay A. All horses were below the detection limit at rest using assay B. Peak elevation occurred 2-6 h post-exercise with both assays (mean, 4.6 ± 1.7 and 4.0 ± 2 h, respectively). Mean peak increase in cTnI was 11.96 ± 9.41 ng/L (range, 1.72-23.76 ng/L) using assay A. Peak concentrations were detectable in three of the horses using assay B and were between 0.039 and 0.051 µg/L (mean: 0.043 ± 0.006 µg/L). All horses returned to baseline within 24 h. MAIN LIMITATIONS: A small (n = 5) convenience sample was used as random sampling was not logistically possible. CONCLUSIONS: All horses experienced an increase in cTnI post-exercise, with peak occurring 2-6 h post-exercise. Cardiac troponin I elevation was detected earlier using the high-sensitivity assay, which may convey a diagnostic advantage. Targeted studies are needed to determine the significance of these increases.

Troponin assays in the assessment of the equine myocardium.

In 2000, troponin assays were adopted as the test of choice for detection of myocardial injury in man. This decision was made after extensive testing and followed a 60 year search for a biomarker of myocardial damage with sufficient analytical sensitivity and specificity. This has led to proliferation of assays for use in human medicine, each requiring extensive testing and validation before it could be made available on the open market for human use. The search for ever-more analytically sensitive assays and for a standard reference material continues. The adoption of troponin testing in veterinary medicine followed shortly after its development for use in man, providing a much-needed means of detecting and monitoring myocardial damage in horses. However, application of these tests in veterinary medicine has exclusively involved use of assays designed for and clinically validated in human patients. There is no mandated requirement for test validation in veterinary medicine and, while many of these assays have been shown to be capable of detecting equine troponin, the wide diversity of available tests, lack of validation, absence of protocols for their use and lack of standardisation make their application problematic. The objective of this review article is to address this issue, offering guidance where data are available and encouraging caution where there are none. Ultimately, the overall goal of this review is to examine critically the use of troponin assays in the horse and to promote the accurate and appropriate interpretation of valid results.

Analysis of immediate ex vivo release of nitric oxide from human colonic mucosa in gastrointestinally mediated allergy, inflammatory bowel disease and controls.

Nitric oxide (NO) is a local mediator in inflammation and allergy. The aim of this study was to investigate whether live incubated colorectal mucosal tissue shows a direct NO response ex vivo to nonspecific and specific immunological stimuli and whether there are disease-specific differences between allergic and chronic inflammatory bowel disease (IBD). We took biopsies (n=188) from 17 patients with confirmed gastrointestinally mediated food allergy, six patients with inflammatory bowel disease, and six control patients. To detect NO we employed an NO probe (WPI GmbH, Berlin, Germany) that upon stimulation with nonspecific toxins (ethanol, acetic acid, lipopolysaccharides), histamine (10(-8)-10(-4)M), and immune-specific stimuli (anti-IgE, anti-IgG, known food allergens) directly determined NO production during mucosal oxygenation. Non-immune stimulation of the colorectal mucosa with calcium ionophore (A23187), acetic acid, and ethanol induced a significant NO release in all groups and all biopsies. Whereas, immune-specific stimulation with allergens or anti-human IgE or -IgG antibodies did not produce significant release of NO in controls or IBD. Incubation with anti-human IgE antibodies or allergens produced a ninefold increase in histamine release in gastrointestinally mediated allergy (p<0.001), but anti-human IgE antibodies induced NO release in only 18% of the allergy patients. Histamine release in response to allergens or anti-human IgE antibodies did not correlate with NO release (r(2)=0.11, p=0.28). These data show that nonspecific calcium-dependent and toxic mechanisms induce NO release in response to a nonspecific inflammatory signal. In contrast, mechanisms underlying immune-specific stimuli do not induce NO production immediately.

Small-bowel capsule endoscopy in patients with gastrointestinal food allergy.

BACKGROUND: Food allergy may present with a plethora of gastrointestinal and extraintestinal symptoms such as abdominal pain, diarrhea, cardiocirculatory symptoms, cutaneous reactions, or rhinitis. Macropathological lesions like lymphofollicular hyperplasia and erosive or ulcerative lesions have seldom been described in gastroscopy and colonoscopy previously. METHODS: Fifteen patients presenting with unspecific abdominal symptoms in which food allergy was detected in due course were included. During the examination process, those patients showed various indications for small-bowel capsule endoscopy, such as weight loss and anemia. RESULTS: Fourteen (93.3%) of the 15 small-bowel capsule endoscopies could be assessed, showing nonerosive lesions such as erythema, swelling, and lymphoid hyperplasia in 8 patients (57.1%) and erosive lesions such as aphthoid lesions, erosions, and petechiae in 4 patients (28.6%) with food allergy. CONCLUSION: In 15 patients with confirmed food allergy and after exclusion of other diseases, 12 (85.7%) showed various unspecific nonerosive or erosive mucosal lesions within the small bowel, resulting, however, partially in grave consequences such as anemia. Lymphoid hyperplasia was the most prominent finding in 7 patients (50%), albeit infectious disease had been excluded. Anemia improved within 1 year after adequate antiallergic treatment.

Celiac disease in a patient with a congenital deficiency of intestinal enteropeptidase.

We report on a 40-yr-old man with both primary enteropeptidase deficiency and celiac disease. He suffered from severe intestinal malabsorption and growth failure as a child. Enteropeptidase deficiency was found and pancreatic enzyme replacement therapy resulted in a growth spurt. Enteropeptidase levels in his intestinal mucosa and intraluminal fluid remained very low throughout childhood and early adult life. Celiac disease was confirmed by characteristic abnormalities in tests of intestinal function and in mucosal biopsies, which recovered when he instituted a gluten-free diet. He remains clinically intolerant to gluten as an adult. Enteropeptidase levels have remained abnormally low whether or not his intestinal mucosa has been normal in response to gluten restriction. Enteropeptidase levels have previously been shown to be normal in untreated celiac patients. The relationship between the two disorders remains unclear.

Gastrointestinal bleeding in children: an overview of conditions requiring nonoperative management.

Gastrointestinal bleeding in infants and children is a common problem in the practice of general pediatrics. This report outlines the diagnosis and management of gastrointestinal bleeding in children that does not require surgical or invasive intervention. The spectrum of responsible entities are quite diverse and include a variety of immune-mediated diseases, peptic diseases, drug induced disorders, infections, and coagulation disorders. Through understanding the nature of the above-described problems, appropriate diagnostic and management principles can be applied.

Oncogene expression in patients with familial polyposis coli/Gardner's syndrome.

We evaluated whether c-myc and ras P-21 oncogene expression could identify familial polyposis coli/Gardner's syndrome patients at risk for colon cancer. Monoclonal antibodies recognizing c-myc and ras P-21 proteins were used in immunohistochemistry to stain 26 paraffin-embedded tissue specimens collected over 12 years from 5 familial polyposis coli/Gardner's syndrome patients at various stages of their disease. Differences in staining intensity between specimens were noted with each of the two tissues markers; however, c-myc showed also a distinct cellular staining pattern in patients with advanced histologic features. The c-myc oncogene exhibited strong homogeneous cytoplasmic staining in all adenocarcinoma specimens; weak cytoplasmic staining was found in normal biopsies and in 5/10 familial polyposis coli/Gardner's syndrome specimens in the early stage of disease. In contrast, a heterogeneous staining pattern with a strong supranuclear and weak nuclear and cytoplasmic staining was demonstrated in specimens with advanced histologic features of familial polyposis coli/ Gardner's syndrome and also in postoperative ileal specimens. Anti-ras P-21 antibody, on the other hand, demonstrated a homogeneous cytoplasmic staining pattern in all specimens. We feel that the c-myc oncogene expression, in distinction to that of ras P-21, has potential as a genetic tissue marker to distinguish early from more progressive disease.

Serum soluble interleukin-2 receptor, soluble CD8 and soluble intercellular adhesion molecule-1 levels in Crohn's disease, celiac disease, and systemic lupus erythematosus.

We investigated soluble interleukin-2 receptor (sIL-2R), soluble CD8 (sCD8) and soluble intercellular adhesion molecule-1 (sICAM-1) levels in the sera of patients with non-malignant diseases believed to have an autoimmune or immunosuppressive component, Crohn's disease, celiac disease, and systemic lupus erythematosus (SLE). Sera of healthy blood donors served as controls. All samples were analyzed by commercial ELISA kits for sIL-2R, sCD8, and sICAM-1. Our control level of sIL-2R (x +/- S.D) was 395 +/- 84 units/ml, sCD8 (x +/- S.D.) 263 +/- 90 units/ml and sICAM-1 405 +/- 118 ng/ml. The 8 Crohn's disease patients had an average sIL-2R level of 920 +/- 329 units/ml, and an average sCD8 level of 355 +/- 91 units/ml, and sICAM-1 952 +/- 329 ng/ml. The four celiac disease patients had an average sIL-2R concentration of 1740 +/- 1071 units/ml, a sCD8 level of 460 +/- 320 units/ml and sICAM-1 1221 +/- 720 ng/ml. The three systemic lupus erythematosus patients had an average sIL-2R of 1023 +/- 123 units/ml, and an average sCD8 of 395 +/- 69 units/ml, and sICAM-1 1153 +/- 219 ng/ml. Thus, sIL-2R and sICAM-1 were significantly elevated over control levels in all 3 patient groups, and sCD8 was mildly elevated. These results indicate enhanced immune activation which may be a common feature in the onset and/or progression of these idiopathic illnesses.

Small intestinal mucosa changes, including epithelial cell proliferative activity, of children receiving total parenteral nutrition (TPN).

We examined the small intestinal histology disaccharidase activities as well as the incorporation of [3H]thymidine into DNA of biopsies maintained in organ culture from seven children (ages 9 months to 5 years) receiving total parenteral nutrition (TPN). Three children suffered from inflammatory bowel disease and received TPN for one month (short term). Four required long-term TPN (> 9 months) for short-bowel syndrome. DNA was extracted from the samples following serial precipitation with perchloric acid. Results were compared to those from 22 age-matched children investigated for abdominal pain or chronic diarrhea. Short-term TPN resulted in slightly lower lactase, sucrase, and palatinase activities that were not statistically different from controls. Long-term TPN resulted in focal mild villus atrophy and a decrease in disaccharidase activity in two patients. Biopsies from long-term TPN patients incorporated less thymidine compared to those of controls (P < 0.001) when data was expressed per total biopsy (3.6 +/- 1.1 vs. 8.4 +/- 1.1 fmol) or per milligram of tissue (1.0 +/- 0.12 vs 2.7 +/- 0.7 fmol). The above data are in general agreement with the hypoplastic effect of TPN in animals. However, in children, much longer periods of TPN are required to realize the changes.

Incidence of celiac disease identified by the presence of serum endomysial antibodies in children with chronic diarrhea, short stature, or insulin-dependent diabetes mellitus.

We determined the incidence of celiac disease in the western New York area to be 1.29 per 10,000 live births. Celiac disease occurred in 29 children with gastrointestinal symptoms. Two children (1.7%) of 117 with short stature and 10 (4.0%) of 211 with diabetes mellitus had serum anti-endomysial antibodies. We conclude that the incidence of childhood celiac disease in our area is much less than that reported in Europe.

Reversed-phase liquid chromatography of the opioid peptides. 3. Development of a microanalytical system for opioid peptides involving microbore liquid chromatography, post-column derivatization and laser-induced fluorescence detection.

A microanalytical system has been developed for the determination of peptides in small samples. Naphthalene-2,3-dicarboxaldehyde-beta-mercaptoethanol (NDA-BME) was used as the labelling reagent system as an alternative to NDA-cyanide (NDA-CN) because of the faster labelling when CN was replaced by a thiol. The fluorescence characteristics of the NDA-thiol adducts, N-substituted 1-alkylthiobenz[f]isoindoles (TBIs), were found to be different from the previously described cyanobenz[f]isoindole (CBIs) adducts formed by the reaction of primary amines with NDA-CN. The excitation maximum of the TBI adducts was at 460 nm, which was closer to the 457.9 nm argon-ion laser line, than the 440-nm maximum of the CBI adduct. The limit of detection for leucine enkephalin was 36 fmol (S/N = 3) and linearity was proven for greater than 2 orders of magnitude, from 45 fmol to 9 pmol for an injection volume of 60 nl. The detectability was limited by the high background noise produced by the post-column derivatization system. The utility of the system was demonstrated for the analysis of methionine enkephalin and its potential oxidation products, using leucine enkephalin as a suitable internal standard.

Stromal cells derived from spleen or bone marrow support the proliferation of rat natural killer cells in long-term culture.

Rat nylon wool nonadherent bone marrow cells were propagated for up to 75 days in co-culture with stromal cells derived from either spleen or bone marrow. Interleukin (IL) 1 enhanced the ability of spleen stroma to support the long-term culture of natural killer (NK) cells, ostensibly by inducing these support cells to synthesize other cytokines. Flow cytometry studies indicated that the nylon wool separation procedure enriched the concentrations of mature NK cells from 7.9% to 38.1% for splenocytes and from 3.8% to 19.5% for bone marrow cells. Analyses of the adherent zones of suspended nylon screen NK cell cultures revealed substantial numbers of large granular lymphocytes that expressed NK 323+/MOM/3F12/F2- phenotypes. The presence of both mature and immature cells of the NK lineage in this matrix was inferred by the presence of both IL-2 receptor (IL-2R) positive and IL-2R negative, and OX-8+ and OX-8- NK 323+ cells over the greater than 4-month experimental period. Suspended nylon screen cultures displayed a greater potential for producing cytolytic cells than either co-cultures of bone marrow nonadherent cells on stroma monolayers or suspension cultures. The large granular lymphocytes produced in suspended nylon screen cultures could be transformed into active killers of YAC-1 targets by IL-2. In contrast to bone marrow nonadherent cells, more splenic nylon-wool-passed cells displayed a mature NK phenotype, but their proliferative potential and ability to be transformed into cytolytic cells by IL-2 decreased rapidly in culture. In the suspended nylon screen culture system, NK cells migrate from the underlying stroma in stages as they mature, retain their cytolytic potential, and manifest a capacity for self-renewal. Cultured cells were routinely dissociated into single cell suspensions via enzyme treatment and were reinoculated onto "fresh" nylon screen/stromal cell templates after passage through nylon wool columns. These co-cultures continued to generate cytolytic cells in numbers greater than those of the initial inoculum.

Immunology of inflammatory bowel disease: summary of the proceedings of the Subcommittee on Immunosuppressive Use in IBD.

As outlined, scanty data exist with regard to immunologic therapy in children with IBD despite the fact that the pediatric population affords a unique opportunity for clinical evaluation. Children are less affected by modifying conditions such as smoking, alcohol ingestion, and the long-term use of medications, and because of their specific needs for ponderal and linear growth, children might benefit most from immunological therapy that has been proven to be steroid sparing. Therefore, clinical trials to evaluate the efficacy of 6-MP and/or azathioprine in growing children with Crohn's disease would appear to provide a fruitful avenue for collaborative research. Efforts to organize a multicenter evaluation of these agents have been initiated. The studies are crucial in evaluating the efficacy and safety of immunosuppressive therapy in the pediatric population with IBD.

Human intestinal disaccharidase activities: correlations with age, biopsy technique, and degree of villus atrophy.

The relationship between intestinal morphology, disaccharidase activity, and disaccharide absorption is controversial. A retrospective study of 798 consecutive biopsies was performed to determine whether disaccharidase activities varied by subject age, biopsy technique, and degree of villus atrophy. Lactase activity was inversely correlated with age in the absence or presence of villus atrophy; sucrase, maltase, and palatinase activities did not correlate with age. Biopsies obtained by capsule or endoscopy had similar disaccharidase activities. In subjects 24 months of age or younger, the degree of mucosal injury was inversely correlated with lactase activity. In subjects older than 24 months, the degree of mucosal injury was inversely correlated with maltase and, to a lesser extent, lactase activities. The data suggest that disaccharidase activities in mucosal biopsies, whether obtained by endoscopy or capsule, are diminished in the presence of mucosal injury and correlate inversely with the degree of injury.

High-fat semielemental diet in the treatment of protracted diarrhea of infancy.

The capacity for greater fat absorption relative to carbohydrate absorption in protracted diarrhea of infancy was studied in a developed and a developing country (Buffalo, NY, and Bangkok, Thailand). Fifty patients with protracted diarrhea in the first year of life (defined as liquid stools of more than 20 mL/kg per day with more than a 14-day duration) were randomly assigned to receive either a standard semielemental diet (Pregestimil) or a high-fat semielemental diet that contained 40% more fat. The increased fat was largely in the form of medium-chain triglycerides, with the new diet providing 60% of the fat as medium-chain triglycerides compared with 40% in the standard diet. Tolerance to both diets was good in both studies. Both groups showed adequate weight gain and an improvement in anthropometric and biochemical parameters. The patients receiving the high-fat diet showed no initial weight loss, however, and their weight gain was initiated earlier. Cumulative weight gain was also higher in the group receiving the high-fat semielemental diet. Fecal fat analyses were performed after 1 week of therapy. There was no difference observed in the coefficient of fat absorption between the groups receiving the two formulas, indicating that infants with protracted diarrhea may be able to tolerate a higher fat intake than is normally provided. As carbohydrate intolerance is known to be a complicating factor when using semielemental enteral feeds for infants with protracted diarrhea, a higher-fat semielemental diet may be the most appropriate way to provide adequate caloric intake.

Carnitine ester excretion in pediatric patients receiving parenteral nutrition.

Carnitine plasma concentrations and the excretion of carnitine and individual carnitine esters were determined in 25 children and adolescents with gastrointestinal diseases receiving carnitine-free parenteral nutrition for at least 1 mo using radiochemical and radioisotopic exchange HPLC methods. Children less than 12-y-old usually had carnitine plasma concentrations less than -2 SD from the normal mean for age, whereas patients greater than 12-y-old had carnitine plasma concentrations within the normal range. Age was the only variable to correlate significantly with plasma carnitine concentrations during parenteral nutrition. Free carnitine (FC) excretion was closely correlated with plasma FC concentrations and minimal at values less than 25 mumols/L. The excretion of FC and short-chain acylcarnitines was reduced by an order of magnitude in younger compared with older patients and controls, but the excretion of "other" acylcarnitines was less affected. Some of the latter were tentatively identified using gas-liquid chromatographic and mass spectroscopic techniques as unsaturated and/or branched medium-chain carnitine esters with a carbon chain of C8-C10. The results suggest that FC and short-chain acylcarnitine are conserved by the kidney in nutritional carnitine deficiency but that there may be an obligatory renal excretion of other carnitine esters that contributes to the development of hypocarnitinemia in the younger age group.

Catheter-related complications in 35 children and adolescents with gastrointestinal disease on home parenteral nutrition.

A 7-year experience with home parenteral nutrition (HPN) in 35 children and adolescents suffering from severe gastrointestinal diseases is reported. The average duration of HPN was 577 days with a mean of 2.9 catheters per patients. There was a total of 82 episodes of proven catheter-related sepsis, an average of 1.5 septic episodes per patient year. In about half of these instances, the catheter had to be removed. Coagulase-negative and -positive staphylococci were the most common organisms isolated. All four Candida infections led to removal of the catheter. Children requiring HPN from early infancy had a higher frequency of catheter-related infections than those started on HPN after the first year of life. In four cases, clinically significant thrombotic complications occurred. The results suggest that even under optimal conditions of catheter placement and with extensive education in aseptic catheter handling, infection is still relatively common in children receiving HPN. However, there was no mortality related to this complication.