Detecting early kidney damage in horses with colic by measuring matrix metalloproteinase -9 and -2, other enzymes, urinary glucose and total proteins

BACKGROUND: The aim of the study was to investigate urine matrix metalloproteinase (MMP-2 and -9) activity, alkaline phosphatase/creatinine (U-AP/Cr) and gamma-glutamyl-transpeptidase/creatinine (U-GGT/Cr) ratios, glucose concentration, and urine protein/creatinine (U-Prot/Cr) ratio and to compare data with plasma MMP-2 and -9 activity, cystatin-C and creatinine concentrations in colic horses and healthy controls. Horses with surgical colic (n = 5) were compared to healthy stallions (n = 7) that came for castration. Blood and urine samples were collected. MMP gelatinolytic activity was measured by zymography. RESULTS: We found out that horses with colic had significantly higher urinary MMP-9 complex and proMMP-9 activities than horses in the control group. Colic horses also had higher plasma MMP-2 activity than the control horses. Serum creatinine, although within reference range, was significantly higher in the colic horses than in the control group. There was no significant increase in urinary alkaline phosphatase, gamma-glutamyltranspeptidase or total proteins in the colic horses compared to the control group. A human cystatin-C test (Dako Cytomation latex immunoassay(® )based on turbidimetry) did not cross react with equine cystatin-C. CONCLUSION: The results indicate that plasma MMP-2 may play a role in the pathogenesis of equine colic and urinary MMP-9 in equine kidney damage

The Impact of Local Genome Sequence on Defining Heterochromatin Domains

Characterizing how genomic sequence interacts with trans-acting regulatory factors to implement a program of gene expression in eukaryotic organisms is critical to understanding genome function. One means by which patterns of gene expression are achieved is through the differential packaging of DNA into distinct types of chromatin. While chromatin state exerts a major influence on gene expression, the extent to which cis-acting DNA sequences contribute to the specification of chromatin state remains incompletely understood. To address this, we have used a fission yeast sequence element (L5), known to be sufficient to nucleate heterochromatin, to establish de novo heterochromatin domains in the Schizosaccharomyces pombe genome. The resulting heterochromatin domains were queried for the presence of H3K9 di-methylation and Swi6p, both hallmarks of heterochromatin, and for levels of gene expression. We describe a major effect of genomic sequences in determining the size and extent of such de novo heterochromatin domains. Heterochromatin spreading is antagonized by the presence of genes, in a manner that can occur independent of strength of transcription. Increasing the dosage of Swi6p results in increased heterochromatin proximal to the L5 element, but does not result in an expansion of the heterochromatin domain, suggesting that in this context genomic effects are dominant over trans effects. Finally, we show that the ratio of Swi6p to H3K9 di-methylation is sequence-dependent and correlates with the extent of gene repression. Taken together, these data demonstrate that the sequence content of a genomic region plays a significant role in shaping its response to encroaching heterochromatin and suggest a role of DNA sequence in specifying chromatin state

Metabolic changes in concussed American football players during the acute and chronic post-injury phases

<p>Abstract</p> <p>Background</p> <p>Despite negative neuroimaging findings many athletes display neurophysiological alterations and post-concussion symptoms that may be attributable to neurometabolic alterations.</p> <p>Methods</p> <p>The present study investigated the effects of sports concussion on brain metabolism using ¹H-MR Spectroscopy by comparing a group of 10 non-concussed athletes with a group of 10 concussed athletes of the same age (mean: 22.5 years) and education (mean: 16 years) within both the acute and chronic post-injury phases. All athletes were scanned 1-6 days post-concussion and again 6-months later in a 3T Siemens MRI.</p> <p>Results</p> <p>Concussed athletes demonstrated neurometabolic impairment in prefrontal and motor (M1) cortices in the acute phase where NAA:Cr levels remained depressed relative to controls. There was some recovery observed in the chronic phase where Glu:Cr levels returned to those of control athletes; however, there was a pathological increase of m-I:Cr levels in M1 that was only present in the chronic phase.</p> <p>Conclusions</p> <p>These results confirm cortical neurometabolic changes in the acute post-concussion phase as well as recovery and continued metabolic abnormalities in the chronic phase. The results indicate that complex pathophysiological processes differ depending on the post-injury phase and the neurometabolite in question.</p

Interaction of saddle girth construction and tension on respiratory mechanics and gas exchange during supramaximal treadmill exercise in horses

Objective To determine the effect of girth construction and tension on respiratory mechanics and gas exchange during supramaximal treadmill exercise in horses. Methods Six healthy detrained Thoroughbred horses were exercised on a treadmill inclined at 10% at 110% VO(2)max. Horses were instrumented for respiratory mechanics and gas exchange studies, and data were recorded during incremental exercise tests. The animals were exercised for 2 min at 40% VO(2)max, and samples and measurements were collected at 1 min 45 sec. After 2 min, speed was increased to that estimated at 110% VO(2)max and data was collected at 45 sec, 90 sec and every 30 sec thereafter at this speed until the horses fatigued. Horses were run on three occasions with the same racing saddle and saddle packing but using two different girths, either an elastic girth: (EG) or a standard canvas girth (SCG) which is nonelastic. A run with 5 kg tension applied to a standard canvas girth was the control for each horse, with additional runs at 15 kg using either the standard canvas girth or using the elastic girth, The runs were randomised and tensions applied were measured at end exhalation whilst at rest. Results Increasing girth tension was not associated with changes in respiratory mechanical or gas exchange properties. Although girths tightened to 15 kg tension had short run to fatigue times this was not found to be significantly different to girths set at 5 kg resting tension. Girth tensions declined at end exhalation in horses nearing fatigue. Conclusions Loss in performance associated with high girth tensions is not due to alteration of respiratory mechanics. Loss in performance may be related to inspiratory muscles working at suboptimal lengths due to thoracic compression or compression of musculature around the chest. However, these changes are not reflected in altered respiratory mechanical or gas exchange properties measured during tidal breathing during supramaximal exercise. Other factors may hasten the onset of fatigue when horses exercise with tight girths and further studies are required to determine why excessively tight girths affect performance

Measurement of the activation of equine platelets by use of fluorescent-labeled annexin V, anti-human fibrinogen antibody, and anti-human thrombospondin antibody

Objective To investigate the potential use of fluorescent-labeled annexin V, anti-human fibrinogen antibody, and anti-human thrombospondin antibody for detection of the activation of equine platelets by use of flow cytometry. Sample Population-Platelets obtained from 6 Thoroughbreds. Procedure-Flow cytometry was used to assess platelet activation as indicated by detection of binding of fluorescent-labeled annexin V, anti-human fibrinogen antibody, and anti-thrombospondin antibody to unactivated and ADP-, collagen-, platelet activating factor (PAF)-, and A23187-activated equine platelets. Human platelets were used as control samples. Determination of C-14-serotonin uptake and release was used to assess the extent of platelet secretion. Results-Anti-human thrombospondin antibody failed to bind to equine platelets. Annexin V bound to platelets activated with PAF or A23187 when platelets had undergone secretion, Anti-human fibrinogen antibody bound to ADP-, PAF-, and A23817-activated platelets, but binding was not dependent on platelet secretion. The extent of binding of anti-fibrinogen antibody was less in equine platelets, compared with that for human platelets, despite maximal stimulation. Conclusions and Clinical Relevance-Activation of equine platelets can be detected by use of fluorescent-labeled annexin V and anti-human fibrinogen antibody but not by use of anti-human thrombospondin antibody. These flow cytometric techniques have the potential for detection of in vivo platelet activation in horses at risk of developing thrombotic disorders

Effects of sodium citrate. low molecular weight heparin, and prostaglandin E-1 on aggregation, fibrinogen binding, and enumeration of equine platelets

Objective-To investigate the effects of sodium citrate, low molecular weight heparin (LMWH), and prostaglandin E-1 (PGE(1)) on aggregation, fibrinogen binding, and enumeration of equine platelets. Sample Population-Blood samples obtained from 4 Thoroughbreds. Procedure-Blood was collected into syringes in the ratio of 9 parts biood:1 part anticoagulant. Anticoagulants used were sodium citrate, LMWH, sodium citrate and LMWH, or 300 nM PGE(1)/ml of anticoagulant. Platelet aggregation in response to ADP, collagen, and PGE1 was assessed, using optical aggregometry. Platelet activation was evaluated, using flow cytometry, to detect binding of fluorescein-conjugated anti-human fibrinogen antibody. Plasma concentration of ionized calcium was measured, using an ion-selective electrode. Results-Number of platelets (mean +/- SEM) in samples containing LMWH (109.5 +/- 11.3 x 10(3) cells/mul) was significantly less than the number in samples containing sodium citrate (187.3 +/- 30.3 x 10(3) cells/mul). increasing concentrations of sodium citrate resulted in reductions in platelet aggregation and plasma concentration of ionized calcium. Addition of PGE, prior to addition of an agonist inhibited platelet aggregation in a concentration-dependent manner, whereas addition of PGE, 4 minutes after addition of ADP resulted in partial reversal of aggregation and fibrinogen binding. Conclusions and Clinical Relevance-A high concentration of sodium citrate in blood samples decreases plasma concentration of ionized calcium, resulting in reduced platelet aggregation and fibrinogen binding. Platelets tend to clump in samples collected into LMWH, precluding its use as an anticoagulant. Platelet aggregation and fibrinogen binding can be reversed by PGE(1), which may result in underestimation of platelet activation

Effects of Feeding Coenzyme Q10-Ubiquinol on Plasma Coenzyme Q10 Concentrations and Semen Quality in Stallions

Although coenzyme Q10 (CoQ10) serves as an antioxidant and energy source for spermatozoa when added to stallion semen prior to cooling or freezing, the effects of feeding CoQ10 on semen quality have not been studied. We assessed the effects of daily oral ingestion of CoQ10-ubiquinol by stallions on their plasma CoQ10 concentrations and semen quality. Seven mature Andalusian stallions ate 1g ubiquinol/day for 4 weeks followed by a 4-week wash-out period. Four horses initially completed an additional 4-week control period without ubiquinol. Blood was sampled weekly for determination of plasma CoQ10 concentrations. Ejaculates were collected every two weeks and assessed for total motility (TM), progressive motility (PM) and viability (V) after cooling for 24h (T1), immediate cryopreservation (T2), and cryopreservation following 24h cooling (T3). Ingesting ubiquinol resulted in an increase in plasma CoQ10 concentration (p < .001). Two weeks of CoQ10-ubiquinol resulted in improved V with all treatments (T1: p=.007; T2: p=.05; T3: p=.01) and PM with T3 (p=.04). In five stallions, TM and PM were also improved for T1 (p=.01 and p=.02, respectively) and TM increased with T2 (p=.03). Overall, semen quality parameters increased within the first 2 weeks of supplementation, plateaxued at the end of the 4-week supplementation period and persisted after discontinuing ubiquinol until the end of the sampling period (8 weeks). Feeding 1g CoQ10-ubiquinol for 4 weeks to breeding stallions improved semen quality after cooling and freezing in 5 of 7 stallions. This could be important for improving reproductive efficiency in stallions