bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raising heels of hind hooves changes the equine coffin, fetlock and hock joint angle: a kinematic evaluation on the treadmill at walk and trot
Authors: PEHAM C. , GIRTLER D. , KICKER C. , LICKA T. 
Published: June 2010

SummaryReasons for performing study: Raised heels are commonly recommended for various equine orthopaedic conditions. However, the simultaneous effect of raised heels on the different joint angles of the equine hindlimb throughout the motion cycle has not been previously evaluated.Objective: To document the simultaneous effect of raised heels on the joint angles of the equine hindlimb coffin, fetlock and hock joints.Methods: Eight sound, adult, Warmblood horses were evaluated barefoot and with a heel wedge of 8 or 16°, walking and trotting on a horizontal treadmill. Markers placed on the dorsal and cranial aspect of the hindlimb were traced using a 3D high speed video system and joint angles calculated.Results: The effects of raising the hindlimb heels by 8 or 16° on the angles of the hindlimb during the stance phase are a reduction of the plantar combined coffin joint and pastern joint angle, a reduction of maximum extension in the fetlock joint, and an increase in maximum hock flexion. The relation between angles did not change significantly during the course of the stance phase in the three measurement situations, with only small differences in time of occurrence of each joint angle maxima and minima.Conclusions: Raising the heels of hind hooves increases flexion of the coffin and hock joints during the stance phases of walk and trot, and a doubling of the angle of the raised heels also doubles the effect on the joint angles investigated. Raised heels reduce the maximum extension of the fetlock joint during the the stance phase at walk and trot.Potential relevance: This study provides evidence for the therapeutic use of raised shoes with heels in horses with pain on maximum hock extension, e.g. spavin.
Exercise‐induced pulmonary haemorrhage during submaximal exercise
Authors: EPP T. S. , McDONOUGH P. , PADILLA D. J. , GENTILE J. M. , EDWARDS K. L. , ERICKSON H. H. , POOLE D. C. 
Published: June 2010

SummaryReasons for performing study:Maximally exercising horses achieve mean pulmonary artery pressures (Ppamean) that exceed the minimum threshold (75 mmHg) estimated for pulmonary capillary rupture and exercise‐induced pulmonary haemorrhage (EIPH). EIPH is not expected to occur during moderate submaximal exercise (i.e. 40–60% VO2max) since Ppameanremains well below this threshold.Hypothesis:Prolonged submaximal exercise (trotting) would precipitate locomotory respiratory uncoupling and cause EIPH. This would be present as a result of the most negative intrapleural pressures (as estimated by the minimum oesophageal pressure; Pœsmin) occurring simultaneously with the most positive Ppa (Ppapeak) to produce estimated maximal pulmonary artery transmural pressures (PATMPmax) that surpass the EIPH threshold.Methods:Five Thoroughbred horses trotted to fatigue (˜25 min) at 5 m/sec on a 10% incline. Ventilation (VE), Pœs, and Ppa were measured at 5 min intervals, and bronchoalveolar lavage (BAL) red blood cells (RBCs) were quantified 45 min post exercise.Results:BAL revealed an increased EIPH (rest: 2.0 ± 1 times 105, exercise: 17 ± 10 times 105RBCs/ml BALF; P<0.05), despite the highest Ppameanreaching only mean ± s.e. 55 ± 3 mmHg, while VE, tidal volume and Pœsminapproached 70–80% of the values achieved at maximal running speeds (10% incline: 12–13 m/sec) by these same horses. The resulting PATMPmaxwas well above the level considered causative of EIPH.Conclusions:The finding of significant EIPH during submaximal exercise broadens the spectrum of performance horses susceptible to EIPH and supports studies that suggest that extravascular factors are of primary importance in the aetiology of EIPH.Potential relevance:Consideration of strategies such as the equine nasal strip for reducing negative extravascular pressures is warranted even for exercise at moderate intensities.
Effects of chronic acetazolamide administration on fluid flux from the pulmonary vasculature at rest and during exercise in horses
Authors: VENGUST M. , STAEMPFLI H. , VIEL L. , HEIGENHAUSER G. 
Published: June 2010

SummaryReasons for performing study:Horses develop high pulmonary pressures during exercise, which force fluid out of pulmonary capillaries. Specific airway diseases in horses, especially those associated with hypoxaemia, hypercapnoea and acidosis may influence pulmonary haemodynamics and pulmonary interstitial fluid equilibrium.Objectives:This study was designed to determine fluid flux (JV‐Al/min) across the lung in exercising horses treated chronically with acetazolamide.Methods:Six horses were exercised on a treadmill until fatigue without (Con) and with chronic carbonic anhydrase (CA) inhibition (AczTr) and associated hypercapnoea and acidosis. Carbonic anhydrase inhibition was achieved with administration of acetazolamide (Acz). Arterial and mixed venous blood were sampled, and V̇CO2and V̇O2measured. Blood volume changes across the lung (ΔBV%) were calculated from changes in plasma protein, haemoglobin and packed cell volume (PCV). Cardiac output (Q̇) was calculated using Fick principle.JV‐Aacross the alveolar‐capillary barrier was then quantified based on Q̇ and ΔBV. Variables were analysed using 2‐way repeated‐measures ANOVA (P<0.05). A significant F ratio was further analysed using Tukeypost hocanalysis.Results:Treatment had a significant effect onJV‐A(P = 0.002). At rest there was noJV‐Ain Con (0.63 ± 0.6 l/min) and AczTr (0.84 ± 0.3 l/min). During exercise Con fluid moved from the pulmonary circulation into the pulmonary interstitium (mean ± s.e.JV‐A9.4 ± 2.4 l/min). This was different from AczTr (mean ± s.e.JV‐A1.8 ± 1.9 l/min), where no transvascular fluxes from pulmonary circulation were present during exercise (P = 0.008).Conclusions:Chronic Acz treatment with associated hypercapnoea and acidosis affectsJV‐Ain lungs of exercising horses. Lung fluid dynamics adapted to hypercapnoea and acidosis with reduction of fluid flow from the pulmonary circulation.Potential relevance: The current data provide comprehensive evidence ofin vivofluid homeostasis in lungs of exercising horses without and with CA inhibition.
Prevalence of inflammatory airway disease in National Hunt horses referred for investigation of poor athletic performance
Authors: ALLEN K. J. , TREMAINE W. H. , FRANKLIN S. H. 
Published: June 2010

SummaryReasons for performing study: Inflammatory airway disease (IAD) is thought to be an important cause of poor performance in young Thoroughbred racehorses. However, little study has been made of IAD in older National Hunt (NH) horses.Objectives: To determine the prevalence of IAD in NH racehorses referred for investigation of poor athletic performance and identify some of the risk factors that may be associated with IAD in this group of horses.Methods: Tracheal mucus was graded, and tracheal wash (TW) and bronchoalveolar lavage (BAL) performed after treadmill exercise in 91 NH horses referred to the University of Bristol. Comparisons were made between the different methods for diagnosing IAD and potential risk factors investigated.Results:Tracheal mucus was observed in 68% and lower airway inflammation identified in 70% of horses. There was poor agreement between TW and BAL techniques for a diagnosis of IAD. The prevalence of increased proportions of neutrophils in TW was 40% compared with 59% in BAL. There was a significant association between presence of tracheal mucus and increased neutrophils in TW but not between tracheal mucus and BAL cytology. No significant association between IAD and age, EIPH or URT obstruction was observed.Conclusions: Inflammatory airway disease was a common finding in NH horses referred for investigation of poor performance. In contrast to studies in younger, flat racehorses the prevalence of disease did not decrease with increasing age.Potential relevance: Horses of all ages presented for investigation of poor performance require a thorough clinical investigation of the lower airways. The collection of both TW and BAL samples is indicated in order to confirm a diagnosis of IAD.
Factors influencing variation in locomotor‐respiratory coupling in Standardbred Trotters in the field
Authors: COTREL C. , LELEU C. , COUROUCE‐MALBLANC A. 
Published: June 2010

SummaryReasons for performing study:A close relationship between limb and respiratory rhythms has been shown in clinically healthy galloping horses due to mechanical constraints in the thoracic region. This synchronisation leads to a 1/1 ratio between stride frequency (SF) and respiratory frequency (RF) during galloping. Very little is known about locomotor‐respiratory coupling (LRC) during fast trot.Objectives:To investigate stride and respiratory rates during a standardised exercise test on the track in Standardbred Trotters.Methods:Forty‐four French trotters age 2–10 years performed a standardised exercise test consisting of three 3 min steps at constant speeds. Speed (V) of exercise varied between 500 and 750 m/min. Variables measured during exercise: SF, heart rate, RF using a microphone between the nostrils, blood lactate concentration. Physiological variables V4and V200were calculated and race performance index recorded.Results:There was no age‐related difference in RF or in LRC. Two LRC strategies were found: around 1/1 ratio and 3/2 ratio between SF and RF, respectively. A relationship between SF/RF ratio and physiological parameters showed a higher LRC in good performers because of a lower RF during submaximal and maximal exercise.Conclusion:RF is significantly lower and LRC significantly higher in good compared to poor performers.Potential relevance:Investigation is required to ensure that the breathing techniques of trotters may be used in the selection process of racehorses.
Effects of dietary energy source and physical conditioning on insulin sensitivity and glucose tolerance in Standardbred horses
Authors: PRATT S. E. , GEOR R. J. , McCUTCHEON L. J. 
Published: June 2010

SummaryReasons for performing study: There is evidence that adaptation to diets rich in nonstructural carbohydrates (NSC) contributes to the development of insulin resistance in horses. To date, however, no study in horses has examined the effects of physical conditioning on diet‐associated alterations in insulin sensitivity and glucose tolerance.Objectives:To examine the effects of adaptation to concentrate feeds rich in NSC or fat on insulin sensitivity and glucose tolerance in horses, both in the sedentary state and after a subsequent period of physical conditioning.Methods: Fourteen mature Standardbred horses underwent both a euglycaemic‐hyperinsulinaemic clamp (EHC) and oral glucose tolerance test (OGTT) after each of the following phases:Baseline‐ fed only forage cubes for 3 weeks;Diet‐ horses were randomly assigned to receive either a high NSC (S) concentrate or a high fat concentrate (F) with forage cubes for 6 weeks; andDiet x Exercise‐ horses remained on the assigned ration and underwent a 7 week period of physical conditioning. An incremental exercise test was performed before, and after, theDiet x Exercisephase for measurement of the peak rate of oxygen consumption (V̇O2peak).Results:In both diet groups, there was an approximately 10% increase in mean V̇O2peakafter physical conditioning. The mean rate of glucose disposal (M) per unit of serum insulin (I) during the EHC [M/I ratio] in S horses was 30% lower (P<0.05) in theDietphase when compared toBaseline, but not different fromBaselineafter physical conditioning. The S diet also resulted in a greater (P<0.05) OGTT insulin response (area under the insulin vs. time curve, AUCINS) in bothDietandDiet x Exercisephases when compared toBaseline. In F, insulin sensitivity (mean M/I ratio) and glucose tolerance were unchanged during the study.Conclusions and potential relevance:Feeding a diet rich in NSC for 6 weeks resulted in decreased insulin sensitivity and impaired glucose tolerance. Physical conditioning lessened the effects of the high NSC diet on insulin sensitivity, as evidenced by the return to baseline M/I, but did not mitigate the impaired glucose tolerance. Decreased insulin sensitivity has been implicated in the development of obesity and laminitis in horses and the present findings provide support for avoidance of concentrates with high NSC in the dietary management of horses at risk for the development of these conditions.
Interval exercise alters feed intake as well as leptin and ghrelin concentrations in Standardbred mares
Authors: GORDON M. E. , McKEEVER K. H. , BOKMAN S. , BETROS C. L. , MANSO‐FILHO H. , LIBURT N. , STRELTSOVA J. 
Published: June 2010

SummaryReasons for performing study: Horses in training tend to become inappetant; however, the mechanism responsible for this training‐induced inappetance is not known.Hypothesis: Training and/or ulcers alter the feed intake (FI) and hormonal and/or biochemical (active ghrelin, leptin, glucose, insulin and cortisol) responses to acute high intensity exercise.Methods: Eight Standardbred mares underwent 3 interval exercise tests (IET) and 3 parallel control tests (CON) before (IET1) and after 8 weeks of training (IET2) and after treatment for gastric ulcers (IET3). Plasma samples were taken before (0 min), during (last 10 sec of velocities eliciting 40, 100 and 20% VO2max), and after (30 min, 60 min, 24 h) exercise (EX) or CON tests for RIA and colorimetric measurement of the concentrations of the above parameters. Samples were also collected before and after feeding. Horses were trained at a work intensity of 70% HRmaxfor 30 min/day, 5 days per week with FI measured daily.Results:There were no changes (P>0.05) in any variable during the parallel control trials. However, there was a mismatch between FI and digestible energy (DE) requirements (P<0.05) with EX horses not meeting their DE requirements during the post training IETs. During all IETs, ghrelin, glucose and cortisol increased (P<0.05) during EX. Leptin only increased (P<0.05) during EX in the post training IETs. Insulin remained low during EX, but increased (P<0.05) post EX.Conclusion: High intensity exercise appeared to be associated with decreases in FI and alterations of leptin and ghrelin.Potential relevance: More research is needed to determine if there is a relationship between alterations of these hormones and changes in FI in horses that lose weight while in training.
Oral vitamin E supplementation on oxidative stress, vitamin and antioxidant status in intensely exercised horses
Authors: WILLIAMS C. A. , CARLUCCI S. A. 
Published: June 2010

SummaryReasons for performing study: Vitamin E is the most commonly supplemented antioxidant in horses; however, previous research is not conclusive as to the recommended level for exercising horses.Objective: To evaluate the effects of 3 levels of vitamin E supplementation on oxidative stress and vitamin/antioxidant status in intensely exercised horses to determine the optimal level of vitamin E supplementation.Methods: Twelve unfit Standardbreds were divided into 3 groups, supplemented orally with 0 (CON), 5000 (MOD), or 10,000 (HI) iu/day of DL‐α‐tocopheryl acetate. The 3 times 3 Latin square design consisted of three 4 week supplementation periods with 4 week wash out periods between. After each period, horses underwent a treadmill interval exercise test. Blood samples were collected and heart rate (HR) measured before, during and after exercise. Data were analysed using ANOVA with repeated measures in SAS.Results: The CON group had lower HR throughout the test compared to the MOD and HI groups (P<0.05). There was an increase in plasma retinol (RET), β‐carotene (BC), red blood cell total glutathione and glutathione peroxidase with exercise (P<0.05), but all groups returned to baseline after 24 h. Plasma α‐tocopherol (TOC) increased from baseline with exercise (P<0.0001) in all groups; treatment differences were observed at 24 h (P<0.05). The HI and CON groups had lower BC compared to the MOD group (P = 0.05).Conclusions: Horses supplemented with vitamin E, at nearly 10‐times the 1989 NRC recommended level, did not experience lower oxidative stress compared to control horses. Additionally, lower plasma BC levels observed in the HI group, which may indicate that vitamin E has an inhibitory effect on BC metabolism.Potential relevance: Supplementation above control levels is not more beneficial to oxidative stress and antioxidant status in intensely exercising horses; indeed, levels 10 times in excess may be detrimental to BC and should be avoided.
CD3+ and BLA.36+ cells do not occur in the epidermis and adnexal epithelia of normal equine skin
Authors: TRANCHINA M. M. , SCOTT D. W. , McDONOUGH S. P. 
Published: June 2010

SummaryA small population of resident T lymphocytes is present in the healthy human and murine epidermis. However, resident epidermal lymphocytes have not been reported in normal skin of the horse. Skin biopsy specimens from the normal skin of 27 horses were examined histologically and immunohistochemically for the presence of lymphocytes, CD3+ cells and BLA.36+ cells in epidermis and adnexal epithelia. All examinations were negative. It appears that lymphocytes occur rarely, if at all, in the epidermis and adnexal epithelia of normal horse skin. Hence, the presence of lymphocytes in these structures should be considered abnormal.
Complete Nucleotide Sequence of
Klebsiella pneumoniae
Multidrug Resistance Plasmid pKP048, Carrying
bla
KPC-2
,
bla
DHA-1
,
qnrB4
, and
armA
Authors: Jiang Yan , Yu Dongliang , Wei Zeqing , Shen Ping , Zhou Zhihui , Yu Yunsong 
Published: June 2010

ABSTRACT

The
Klebsiella pneumoniae
multidrug resistance plasmid pKP048 was completely sequenced. This plasmid carries several important resistance determinants, such as
bla
KPC-2
,
bla
DHA-1
,
qnrB4
, and
armA
, which confer resistance to carbapenems, cephalosporins, fluoroquinolones, and aminoglycosides, respectively. Analysis of the finished 151,188-bp sequence data revealed 163 putative genes, 108 of which were assigned functions such as replication, stable inheritance, antibiotic resistance, a mobile element, conjugal transfer, and a restriction-modification system, showing the strong phylogenetic mosaicism and plasticity of the plasmid.
Underestimation of Vancomycin and Teicoplanin MICs by Broth Microdilution Leads to Underdetection of Glycopeptide-Intermediate Isolates of
Staphylococcus aureus
Authors: Vaudaux Pierre , Huggler Elzbieta , Bernard Louis , Ferry Tristan , Renzoni Adriana , Lew Daniel P. 
Published: June 2010

ABSTRACT

Broth microdilution was compared with tube macrodilution and a simplified population analysis agar method for evaluating vancomycin and teicoplanin MICs and detecting glycopeptide-intermediate isolates of
Staphylococcus aureus
. Modal vancomycin and teicoplanin MICs recorded by tube macrodilution and the agar plate assay, which both used inocula of 10
6
CFU, were significantly higher (2 μg/ml) against a panel of borderline glycopeptide-susceptible and glycopeptide-intermediate methicillin-resistant
S. aureus
(MRSA) bloodstream isolates compared to broth microdilution (1 μg/ml). Vancomycin and teicoplanin MIC distributions by tube macrodilution and agar testing were also markedly different from those evaluated by broth microdilution. The 20-fold-lower inoculum size used for broth microdilution compared to macrodilution and agar MIC assays explained in part, but not entirely, the systematic trend toward lower vancomycin and teicoplanin MICs by microdilution compared to other methods. Broth microdilution assay led to underdetection of the vancomycin-intermediate
S. aureus
(VISA) phenotype, yielding only three VISA isolates, for which vancomycin MICs were 4 μg/ml compared to 8 and 19 VISA isolates detected by macrodilution and agar testing, respectively. While macrodilution and agar testing detected 7 and 22 isolates with elevated teicoplanin MICs (8 μg/ml), respectively, broth microdilution failed to detect such isolates. Detection rates of isolates with elevated vancomycin and teicoplanin MICs by macrodilution and agar testing assays were higher at 48 h than at 24 h. In conclusion, the sensitivity of broth microdilution MIC testing is questionable for reliable detection and epidemiological surveys of glycopeptide-intermediate resistance in
S. aureus
isolates.
A Clinical Isolate of
Candida albicans
with Mutations in
ERG11
(Encoding Sterol 14α-Demethylase) and
ERG5
(Encoding C22 Desaturase) Is Cross Resistant to Azoles and Amphotericin B
Authors: Martel Claire M. , Parker Josie E. , Bader Oliver , Weig Michael , Gross Uwe , Warrilow Andrew G. S. , Kelly Diane E. , Kelly Steven L. 
Published: June 2010

ABSTRACT

A clinical isolate of
Candida albicans
was identified as an
erg5
(encoding sterol C22 desaturase) mutant in which ergosterol was not detectable and ergosta 5,7-dienol comprised >80% of the total sterol fraction. The mutant isolate (CA108) was resistant to fluconazole, voriconazole, itraconazole, ketoconazole, and clotrimazole (MIC values, 64, 8, 2, 1, and 2 μg ml
−1
, respectively); azole resistance could not be fully explained by the activity of multidrug resistance pumps. When susceptibility tests were performed in the presence of a multidrug efflux inhibitor (tacrolimus; FK506), CA108 remained resistant to azole concentrations higher than suggested clinical breakpoints for
C. albicans
(efflux-inhibited MIC values, 16 and 4 μg ml
−1
for fluconazole and voriconazole, respectively). Gene sequencing revealed that CA108 was an
erg11 erg5
double mutant harboring a single amino acid substitution (A114S) in sterol 14α-demethylase (Erg11p) and sequence repetition (10 duplicated amino acids), which nullified C22 desaturase (Erg5p) function. Owing to a lack of ergosterol, CA108 was also resistant to amphotericin B (MIC, 2 μg ml
−1
). This constitutes the first report of a
C. albicans erg5
mutant isolated from the clinic.
Staphylococcus aureus
TargetArray: Comprehensive Differential Essential Gene Expression as a Mechanistic Tool To Profile Antibacterials
Authors: Xu H. Howard , Trawick John D. , Haselbeck Robert J. , Forsyth R. Allyn , Yamamoto Robert T. , Archer Rich , Patterson Joe , Allen Molly , Froelich Jamie M. , Taylor Ian , Nakaji Danny , Maile Randy , G. C. Kedar , Pilcher Marshall , Brown-Driver Vickie , McCarthy Melissa , Files Amy , Robbins David , King Paula , Sillaots Susan , Malone Cheryl , Zamudio Carlos S. , Roemer Terry , Wang Liangsu , Youngman Philip J. , Wall Daniel 
Published: June 2010

ABSTRACT

The widespread emergence of antibiotic-resistant bacteria and a lack of new pharmaceutical development have catalyzed a need for new and innovative approaches for antibiotic drug discovery. One bottleneck in antibiotic discovery is the lack of a rapid and comprehensive method to identify compound mode of action (MOA). Since a hallmark of antibiotic action is as an inhibitor of essential cellular targets and processes, we identify a set of 308 essential genes in the clinically important pathogen
Staphylococcus aureus
. A total of 446 strains differentially expressing these genes were constructed in a comprehensive platform of sensitized and resistant strains. A subset of strains allows either target underexpression or target overexpression by heterologous promoter replacements with a suite of tetracycline-regulatable promoters. A further subset of 236 antisense RNA-expressing clones allows knockdown expression of cognate targets. Knockdown expression confers selective antibiotic hypersensitivity, while target overexpression confers resistance. The antisense strains were configured into a TargetArray in which pools of sensitized strains were challenged in fitness tests. A rapid detection method measures strain responses toward antibiotics. The TargetArray antibiotic fitness test results show mechanistically informative biological fingerprints that allow MOA elucidation.