Maitohappokuljettajien MCT1, MCT2, MCT4 ja apuproteiini CD147 ilmentyminen hevosen lihaksessa ja punasoluissa

Monocarboxylate transporters (MCTs) transport lactate and protons across cell membranes. During intense exercise, lactate and protons accumulate in the exercising muscle and are transported to the plasma. In the horse, MCTs are responsible for the majority of lactate and proton removal from exercising muscle, and are therefore also the main mechanism to hinder the decline in pH in muscle cells. Two isoforms, MCT1 and MCT4, which need an ancillary protein CD147, are expressed in equine muscle. In the horse, as in other species, MCT1 is predominantly expressed in oxidative fibres, where its likely role is to transport lactate into the fibre to be used as a fuel at rest and during light work, and to remove lactate during intensive exercise when anaerobic energy production is needed. The expression of CD147 follows the fibre type distribution of MCT1. These proteins were detected in both the cytoplasm and sarcolemma of muscle cells in the horse breeds studied: Standardbred and Coldblood trotters. In humans, training increases the expression of both MCT1 and MCT4. In this study, the proportion of oxidative fibres in the muscle of Norwegian-Swedish Coldblood trotters increased with training. Simultaneously, the expression of MCT1 and CD147, measured immunohistochemically, seemed to increase more in the cytoplasm of oxidative fibres than in the fast fibre type IIB. Horse MCT4 antibody failed to work in immunohistochemistry. In the future, a quantitative method should be introduced to examine the effect of training on muscle MCT expression in the horse. Lactate can be taken up from plasma by red blood cells (RBCs). In horses, two isoforms, MCT1 and MCT2, and the ancillary protein CD147 are expressed in RBC membranes. The horse is the only species studied in which RBCs have been found to express MCT2, and the physiological role of this protein in RBCs is unknown. The majority of horses express all three proteins, but 10-20% of horses express little or no MCT1 or CD147. This leads to large interindividual variation in the capacity to transport lactate into RBCs. Here, the expression level of MCT1 and CD147 was bimodally distributed in three studied horse breeds: Finnhorse, Standardbred and Thoroughbred. The level of MCT2 expression was distributed unimodally. The expression level of lactate transporters could not be linked to performance markers in Thoroughbred racehorses. In the future, better performance indexes should be developed to better enable the assessment of whether the level of MCT expression affects athletic performance. In human subjects, several mutations in MCT1 have been shown to cause decreased lactate transport activity in muscle and signs of myopathy. In the horse, two amino acid sequence variations, one of which was novel, were detected in MCT1 (V432I and K457Q). The mutations found in horses were in different areas compared to mutations found in humans. One mutation (M125V) was detected in CD147. The mutations found could not be linked with exercise-induced myopathy. MCT4 cDNA was sequenced for the first time in the horse, but no mutations could be detected in this protein.Tässä tutkimuksessa tutkittiin maitohapon kuljetusta elimistössä eri hevosroduilla. Täysverisellä laukkahevosella punasolujen hyvä maitohaponkuljetuskyky oli muita rotuja yleisempää, mutta yllättäen myös suomenhevosella ominaisuus oli lähes yhtä yleinen. Suuresta koostaan huolimatta hevonen on poikkeuksellisen hyvä urheilija. Kilpahevosella jopa yli puolet ruumiinpainosta koostuu lihaksista. Keuhkojen suuri hapenottokyky, pernan sisältämä punasoluvarasto ja tehokas hapenkuljetus lihaksille johtavat hevosella suureen aerobiseen kapasiteettiin. Kovatehoisessa liikuntasuorituksessa aerobinen energiantuotanto ei kuitenkaan riitä tyydyttämään lihasten energiatarvetta ja aineenvaihdunnan painopiste siirtyy anaerobiselle puolelle. Tämän seurauksena lihaksiin ja vereen kertyy maitohappoa. Veren maitohappopitoisuus on dynaaminen tila ja kuvastaa tasapainoa lihasten maitohapontuotannon, vereen kuljetuksen sekä muiden kudosten maitohapon sisäänoton välillä. Maitohappo tarvitsee kuljettajan päästäkseen solukalvon yli lihassolusta vereen. Monokarboksylaattikuljettajat (MCT) ovat lihassolukalvolla esiintyviä proteiineja, jotka kuljettavat maitohappoa. Kovatehoisen liikuntasuorituksen aikana, kun maitohapon tuotanto on voimakasta, MCT- proteiinit ovat päävastuussa maitohapon kuljetuksesta pois lihassolusta. Samalla MCT:n toiminta poistaa solusta protoneja ja hidastaa näin lihassolun happamoitumista. Hevosen lihaksissa esiintyvät proteiinit MCT1, MCT4 sekä niiden apuproteiini CD147. Tässä tutkimuksessa sekä kylmä- että lämminverisillä ravihevosilla MCT1:den ja CD147:n todettiin esiintyvän erityisesti tyypin I ja IIA lihassyissä, joiden aineenvaihdunta on pääosin aerobista. MCT1:den todennäköinen rooli on kuljettaa maitohappoa polttoaineena käytettäväksi näihin lihassoluihin levossa ja kevyen liikuntasuorituksen aikana ja poistaa maitohappoa soluista kovatehoisessa rasituksessa. Ihmisellä harjoittelu lisää MCT1:den ja MCT4:n ilmenemistä lihassolukalvolla. Tässä tutkimuksessa MCT1:den esiintyminen lisääntyi hevosilla enemmän oksidatiivisissa tyypin I ja IIA lihasoluissa verrattuna vähemmän oksidatiivisiin IIB soluihin. Ihmisillä MCT- proteiinien mutaatioiden on todettu aiheuttavan heikentynyttä rasituksensietokykyä ja lihasoireita. Lihasongelmat ovat hevosilla yleisiä ja jopa 7%:lla kilpahevosista on todettu olevan lihasperäinen suorituskykyongelma. Tässä tutkimuksessa tutkittiin MCT1, MCT4 ja CD147 geenien proteiinia koodaavien alueiden sekvenssejä terveillä hevosilla ja lihasvaivoista kärsivillä hevosilla. Mutaatioita löydettiin, mutta niitä ei kuitenkaan pystytty yhdistämään lihasongelmiin. Maitohappoa voidaan kuljettaa plasmasta myös punasolujen sisään, mikä mahdollistaa maitohapon tuotannon jatkumisen pidempään lihaksissa ennen lihaksen väsymistä. Hevosella kilpailun jälkeen jopa 50% maitohaposta voidaankin löytää tilapäisvarastosta punasolujen sisältä. Hevosella kaksi proteiinia MCT1 ja MCT2 sekä apuproteiini CD147 esiintyvät punasolukalvolla. Hevonen on ainoa laji, jonka punasoluista on löydetty MCT2. Sen fysiologinen merkitys punasoluissa on tuntematon. Suurin osa hevosista ilmentää punasoluissa molempia MCT- proteiineja, mutta 10-20% hevosista vain MCT2:ta. Tämä johtaa suureen vaihteluun maitohapon kuljetuskyvyssä punasoluihin ja hevoset voidaan tämän ominaisuuden perusteella jakaa kahteen ryhmään jo pikkuvarsoina. Tässä tutkimuksessa nämä kaksi ryhmää todettiin kolmessa tutkitussa hevosrodussa: suomenhevosessa, lämminverisessä ravihevosessa ja täysverisessä laukkahevosessa. Eniten korkeaa maitohaponkuljetuskykyä esiintyi täysverihevosilla, mutta yllättäen myös suomenhevosella ominaisuus oli lähes yhtä yleinen. Maitohappokuljettajien yhteyttä täysveristen laukkahevosten suorituskykyyn ei tässä tutkimuksessa pystytty osoittamaan

Insulin dysregulation in a population of Finnhorses and associated phenotypic markers of obesity

Non peer reviewe

Risk factors for bit-related lesions in Finnish trotting horses

Background Bit-related lesions in competition horses have been documented, but little evidence exists concerning their potential risk factors. Objectives To explore potential risk factors for oral lesions in Finnish trotters. Study design Cross-sectional study. Methods The rostral part of the mouth of 261 horses (151 Standardbreds, 78 Finnhorses and 32 ponies) was examined after a harness race. Information on bit type, equipment and race performance was collected. Results A multivariable logistic regression model of Standardbreds and Finnhorses showed a higher risk of moderate or severe oral lesion status associated with horses wearing a Crescendo bit (n = 38, OR 3.6, CI 1.4–8.9), a mullen mouth regulator bit (n = 25, OR 9.9, CI 2.2-45) or a straight plastic bit (n = 14, OR 13.7, CI 1.75-110) compared with horses wearing a snaffle trotting bit (n = 98, P = .002). Bar lesions (67 horses) were more common in horses wearing unjointed bits than in horses wearing jointed bits (Fisher's exact test P < .001). Lesions in the buccal area and the inner lip commissures were not associated with bit type. Using a tongue-tie or an overcheck, galloping, placement in the top three or money earned in the race were not associated with lesion risk. Main limitations The sample size for certain bit types was insufficient for statistical analysis. Conclusions Moderate and severe oral lesion status was more common in horses wearing a Crescendo bit, a mullen mouth regulator bit or a straight plastic bit than in horses wearing a single-jointed snaffle trotting bit. However, lesions were observed regardless of bit type. Further studies on rein tension, the interaction between bit type and rein tension and prevention of mouth lesions in trotters are warranted.Peer reviewe

Hevosten herpesvirus 5 ja nodulaarinen keuhkofibroosi – kirjallisuuskatsaus ja tapausselostus

Equine herpesvirus 5 and nodular pulmonary fibrosis – literature review and case reportPeer reviewe

Improving Group Work Practices in Teaching Life Sciences : Trialogical Learning

Trialogical learning, a collaborative and iterative knowledge creation process using real-life artefacts or problems, familiarizes students with working life environments and aims to teach skills required in the professional world. We target one of the major limitation factors for optimal trialogical learning in university settings, inefficient group work. We propose a course design combining effective group working practices with trialogical learning principles in life sciences. We assess the usability of our design in (a) a case study on crop science education and (b) a questionnaire for university teachers in life science fields. Our approach was considered useful and supportive of the learning process by all the participants in the case study: the students, the stakeholders and the facilitator. Correspondingly, a group of university teachers expressed that the trialogical approach and the involvement of stakeholders could promote efficient learning. In our case in life sciences, we identified the key issues in facilitating effective group work to be the design of meaningful tasks and the allowance of sufficient time to take action based on formative feedback. Even though trialogical courses can be time consuming, the experience of applying knowledge in real-life cases justifies using the approach, particularly for students just about to enter their professional careers.Peer reviewe

Validation of a tail-mounted triaxial accelerometer for measuring foals' lying and motor behavior

Foals' locomotory and lying-down behavior can be an indicator of their health and development. However, measurement tools have not been well described with previously reported attachment sites used on limbs of adult horses unsafe for longer-term data collection in foals. In this study, a tail-mounted three-dimensional accelerometer was validated for monitoring foals lying, standing, and walking behavior. Eleven foals were recruited: four hospitalized and seven at private breeding stables. Accelerometers were attached to the dorsal aspect of the base of each foal's tail and their behavior was video recorded. Hospitalized foals had continuous video monitoring inside their stalls, and the breeding stable's foals were monitored outside at pasture for 1-5 periods (mean 42 minutes per period), depending how long they were at the facility. Acceleration was measured using 100 Hz frequency and mean, maximum, and minimum acceleration were recorded in 5 second epochs for x-, y-, and z-axes. Lying, standing, and walking behavior was monitored from videos of all foals, and the start and end time of each behavior was compared with the corresponding data from the accelerometer. Naive Bayes classifier was developed by using dynamic body acceleration and craniocaudal movement of the tail (tilt along z-axis), to predict a foal's lying behavior. The model was validated; the classifier achieved high accuracy in precision and in classifying foals' lying behavior (specificity, 0.92; sensitivity, 0.89; precision, 0.98; accuracy, 0.92). The overall accuracy for classifying walking and standing was also good, but the precision was poor (0.46 and 0.24, respectively). When standing and walking behavior was combined to a single "standing or walking" class, the precision improved (specificity, 0.62; sensitivity, 0.92; precision, 0.89; accuracy, 0.92). In conclusion, tail-mounted three-dimensional accelerometer can be used for monitoring foals' lying behavior. In addition, information regarding standing and walking can be gained with this method. (C) 2020 The Authors. Published by Elsevier Inc.Peer reviewe

Long-term follow-up on recovery, return to use and sporting activity : a retrospective study of 236 operated colic horses in Finland (2006-2012)

Background: Surgical treatment of colic is expensive and complications may occur. Information on the prognosis and the use of the horse after surgery for colic is important for surgeons and owners. Current literature on return to athletic function after celiotomy is limited. The present study reviewed surgical cases of the Veterinary Teaching Hospital, Helsinki, Finland for 2006-2012. The aim was to follow the population of horses of different breeds for surgical findings, postsurgical complications, long-term recovery and prognosis. The findings and their influence on survival, return to previous or intended use and performance were assessed. Results: Most of the operated horses (82.6%; 195/236) recovered from anesthesia and 74.9% (146/195) were discharged. The total follow-up time was 8 years and 10 months and the median survival time 79.2 months. Age of the horse, location of the abdominal lesion (small vs. large intestine), incidence of postoperative colic, surgical site infection, incisional hernia or convalescence time after surgery, did not significantly affect the probability of performing in the previous or intended discipline after the surgery. A majority of the discharged horses (83.7%) was able to perform in the previous or intended discipline and 78.5% regained their former or higher level of performance. Operated horses had 0.18 colic episodes per horse-year during the long-term follow-up. The incidence of colic was 20.0% within the first year after surgery. Horses operated for large intestinal colic were 3.3-fold more prone to suffer postoperative colic than horses operated for small intestinal colic. The majority of the owners (96.3%) were satisfied with the veterinary care and nearly all (98.5%) evaluated the recovery after the colic surgery to be satisfactory or above. Conclusions: If the horse survives to discharge, prognosis for long-term survival and return to previous level of sporting activity and performance was good after colic surgery in a population of horses of different breeds. None of the factors studied were found to decrease the probability of performing in the same or intended discipline after surgery. The majority of horses were able to return to their previous activity and perform satisfactorily for several years after surgery.Peer reviewe

Comparison of Tracheal Wash and Bronchoalveolar Lavage Cytology in 154 Horses With and Without Respiratory Signs in a Referral Hospital Over 2009−2015

Most equine lower respiratory diseases present as increased airway neutrophilia, which can be detected in tracheal wash (TW) or bronchoalveolar lavage fluid (BALE) cytology samples. The aim was to compare the TW and BALF results in a population of client-owned horses with and without clinical respiratory disease signs. A secondary aim was to determine the sensitivity (Se) and specificity (Sp) of TW and BALF neutrophilia in detecting respiratory disease. The cutoff values for neutrophils were also evaluated. Retrospective data from 154 horses of various breeds that had been subject to both TW and bronchoalveolar lavage (BAL) sampling at rest during 2009-2015 were used. The horses were divided into three groups based on the presenting signs, physical examination, and endoscopy mucus score. Neutrophil counts of >20% in TW and >5% in BAL were considered abnormal. Cytology results between groups, correlations between 1W and BALF cell types, and tracheal mucus score were analyzed. Two graph receiving operating characteristic (ROC) curves of the neutrophil percentage values of TW and BALF were created to determine the optimal cutoff values and to calculate the diagnostic Se and Sp for diagnosing airway inflammation in horses with and without clinical respiratory signs. The Se and Sp of TW and BALF neutrophil percentages were further estimated using a two-test one-population Bayesian latent class model. The two tests showed substantial agreement, and only 17.5% of the horses were classified differently (healthy vs. diseased). The neutrophil percentage was found to correlate between TW and BALF. The Se and Sp of TW were generally higher than for BAL when estimated with area under the curve or Bayesian model. Cutoff values of 17.7% for TW and 7% for BALF were indicated by the ROCs. We conclude that TW is a more sensitive and specific method in our patient population. We suggest that the current neutrophil cutoff values of 20% for 1W and 5% for BALE would still be appropriate to use in clinical diagnosis of airway inflammation. However, further studies with other cell types and in other populations are warranted to determine the best sampling method for individual horses.Peer reviewe

Effects of Bedding Material on Equine Lower Airway Inflammation : A Comparison of Two Peat Beddings, Wood Pellet, and Straw Pellet

The effects of bedding material on air quality are important amongst horses worldwide. Respiratory diseases, especially equine asthma, are highly prevalent with air hygiene playing a major role on the pathophysiology of these diseases. The objective of our study was to investigate the effects of four bedding materials on the respiratory signs, tracheal mucus score, and tracheal wash (TW) and bronchoalveolar lavage fluid (BALF) cytology in healthy adult horses. The study design was a prospective controlled cross-over study, and the subjects were healthy adult riding school horses (n = 32) from a single stable. Wood pellet, straw pellet, and loosely stored peat (Peat 3) were compared to peat packed in plastic-covered bales (Peat 2). Lower airway endoscopy and sampling (TW and BALF) for cytological examination were performed after each 35-day bedding period. The tracheal mucus scores (P = 0.014) and respiratory rate (P = 0.026) were higher during the straw pellet period compared to the Peat 2 period. The respiratory rate was lower during the wood pellet period compared to the Peat 2 period (P = 0.004). The TW neutrophil percentage during the straw pellet period was higher compared to the Peat 2 period (P = 0.0003). The BALF neutrophil percentage was higher during the straw pellet period (P = 0.005) and during the Peat 3 period compared to the Peat 2 period (P = 0.04). We conclude that baled peat (Peat 2) caused lower neutrophil percentages in the airway samples compared to straw pellet and loosely stored peat (Peat 3). No difference was observed between Peat 2 and wood pellet. The information gained from this study may assist veterinarians and horse owners in selecting appropriate bedding materials, especially for horses with equine asthma.Peer reviewe

Behavioral Signs Associated With Equine Cheek Tooth Findings

Equine dental diseases are often underdiagnosed and their signs inadequately reported. Many horse owners have difficulties in recognizing pain-related behavioral signs and in associating them with dental pain. Our objective was to determine what type and degree of dental findings may cause behavioral signs associated with dental pain. In this cross-sectional study, dental examination was performed on 183 adult horses and cheek tooth findings were scored. Owners filled in an internet-based questionnaire including 35 questions concerning eating behavior, bit behavior, and general behavior of the horse. Descriptive statistics and logistic regression analyses were performed. Broadened or darkened fissures [odds ratio (OR) 2.4, 95% confidence interval (CI) 1.04–5.7), complicated fractures (OR 2.3, CI 1.01–5.2) and secondary dentine defects of at least the second degree (OR 3.1, CI 1.2–7.7) were associated with the expression of at least five behavioral signs in the univariable binomial logistic regression analyses. Horses with at least one of these potentially painful cheek tooth findings expressed more signs related to eating behavior, bit behavior, and general behavior than did the other horses. The results suggest that cheek tooth findings indicated by this study as being potentially painful, i.e. broadened or darkened fissures, complicated fractures and secondary dentine defects of at least the second degree, may require intervention, particularly if the horse expresses any behavioral signs that might be related to dental pain.Peer reviewe