Analyze Diet

Topic:Horses

"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
A cross-sectional study on performance evaluation in Italian standardbred horses’ real-time PCR-positive for Theileria equi.
BMC veterinary research    March 5, 2024   Volume 20, Issue 1 79 doi: 10.1186/s12917-024-03908-0
Inflammatory myopathy and perivasculitis have been recently described in horses with chronic equine piroplasmosis (EP). These alterations may be linked to poor performances. The aims of this study were to evaluate the prevalence for EP in clinically healthy Italian Standardbred (IS) racehorses and to compare laboratory parameters and performance metrics between positive and negative horses. Real-time PCR was applied for the detection of T. equi and B. caballi positivity. Haematology parameters, blood chemistry results, subjective muscle mass scores, and performance metrics were compared betwee...
Genome-wide analysis of population structure, effective population size and inbreeding in Iranian and exotic horses.
PloS one    March 5, 2024   Volume 19, Issue 3 e0299109 doi: 10.1371/journal.pone.0299109
Bazvand B, Rashidi A, Zandi MB, Moradi MH, Rostamzadeh J.Population structure and genetic diversity are the key parameters to study the breeding history of animals. This research aimed to provide a characterization of the population structure and to compare the effective population size (Ne), LD decay, genetic diversity, and genomic inbreeding in Iranian native Caspian (n = 38), Turkmen (n = 24) and Kurdish (n = 29) breeds and some other exotic horses consisting of Arabian (n = 24), Fell pony (n = 21) and Akhal-Teke (n = 20). A variety of statistical population analysis techniques, such as principal component analysis (PCA), discriminant analysis of...
Equine Asthma Does Not Affect Circulating Myostatin Concentrations in Horses.
Animals : an open access journal from MDPI    March 4, 2024   Volume 14, Issue 5 799 doi: 10.3390/ani14050799
Kowalik S, O'reilly M, Niedźwiedź A, Kędzierski W.(1) Background: The number of horses suffering from chronic respiratory diseases, resembling human asthma, is increasing but there is still a lack of reliable and accurate methods to detect these disorders. Numerous studies have found elevated plasma concentrations of one of the myokines, namely, myostatin (MSTN), in people suffering from severe asthma. MSTN normally inhibits myoblast proliferation and differentiation through autocrine or paracrine signals. Therefore, given the pathogenesis of asthma, we hypothesize that MSTN could be a useful biomarker of equine asthma. Thus, this study aimed...
Short Road Transport and Slaughter Stress Affects the Expression Profile of Serotonin Receptors, Adrenocortical, and Hematochemical Responses in Horses.
Veterinary sciences    March 3, 2024   Volume 11, Issue 3 113 doi: 10.3390/vetsci11030113
Bruschetta G, Zanghì G, Giunta RP, Ferlazzo AM, Satué K, D'Ascola A, Fazio E.Horse transport is considered a cause of stress in animals and is known to affect the 5-HT concentrations in both the brain and other tissues. The aim of this research was to investigate the effect of horse transportation and slaughter stress on plasma serotonin's concentration and the expression levels of the related 5-HT1B and 5-HT2A receptors in PBMCs. Furthermore, the IL-12 levels and a variety of blood parameters, including triglycerides, total cholesterol, glucose, aspartate aminotransferase, creatine phosphokinase, lactate dehydrogenase, were also considered. This research was carried o...
Forced Handling Decreases Emotionality but Does Not Improve Young Horses’ Responses toward Humans and their Adaptability to Stress.
Animals : an open access journal from MDPI    March 2, 2024   Volume 14, Issue 5 784 doi: 10.3390/ani14050784
Pereira-Figueiredo I, Rosa I, Sancho Sanchez C.Horses are often still exposed to stressful or inadequate conditions and difficult relationships with humans, despite growing concerns about animal welfare. In the present study, we investigated the impact of different approaches of short-term handling sessions on young Lusitanian horses raised on a high-breed farm, specifically on their later adaptability to humans and stressful environments. Thirty-one foals (3 months old ± 15 days), from both sexes, were separated into three groups, one submitted to 3 consecutive days of handling sessions (Int-H), another to one handling session each month...
Dystocia frequency and causes in horses with pregnancy disorders or a history of dystocia: A prospective study.
Reproduction in domestic animals = Zuchthygiene    March 1, 2024   Volume 59, Issue 3 e14541 doi: 10.1111/rda.14541
Ellerbrock M, Krohn J, Büttner K, Wehrend A.Dystocia typically presents a life-threatening condition for both the mare and the foal. This prospective long-term study aimed to ascertain whether mares with prior pregnancy disorders or a history of dystocia were at a higher risk of experiencing subsequent dystocia in comparison to those without such medical antecedents. To achieve this goal, the authors analysed 207 parturitions and 164 mares over a 10-year period. Of these, 57 were associated with pregnancy disorders or prior dystocia (Group 1), while 150 parturitions followed uneventful pregnancies in mares that had not yet experienced d...
A field approach to observing changes in behavioural welfare indicators over 2 years in stabled horses.
Animal : an international journal of animal bioscience    February 29, 2024   Volume 18, Issue 4 101120 doi: 10.1016/j.animal.2024.101120
Ruet A, Lemarchand J, Briant C, Arnould C, Lansade L.In stabled horses, several behaviours are considered to be important indicators of the state of welfare at the individual level: stereotypies, aggressive behaviours towards humans and the "withdrawn", alert, sternal, lateral and observation postures. Until now, these behaviours have been extensively studied in relation to different horse management practices. However, little is known about their changes or consistency over time. This study aimed to investigate differences in the expression of these behaviours assessed on 44 stabled horses during an initial 3-month period and then again on the ...
Equine Piroplasmosis in Asymptomatic Horses of Western Iran: Comparison of Microscopic Examination and Multiplex PCR.
Acta parasitologica    February 29, 2024   doi: 10.1007/s11686-024-00804-3
Mohammad-Naseri A, Shokrani H, Rahmani-Shahraki A.Piroplasmosis is responsible for anemia, fever, loss of physical activity and even death in equines. In epidemiological studies, accurate diagnostic tests are essential for detecting asymptomatic carriers. This study aimed to investigate the prevalence of infection in asymptomatic horses from Lorestan province, western Iran by developing a multiplex PCR. Results: Blood samples were examined by microscopy and multiplex PCR targeting the SSU rRNA gene of Theileria equi and Babesia caballi. Out of the total of 165 horses, 19 (11.51%) and 31 (18.78%) cases were positive for piroplasms by microscop...
Immunoproteomics enable broad identification of new Aspergillus fumigatus antigens in severe equine asthma.
Frontiers in immunology    February 29, 2024   Volume 15 1347164 doi: 10.3389/fimmu.2024.1347164
Jentsch MC, Lübke S, Schrödl W, Volke D, Krizsan A, Hoffmann R, Kaiser-Thom S, Gerber V, Marti E, Wagner B, Schnabel CL.Severe equine asthma (SEA) is a common chronic disease of adult horses with characteristic recurrent airway obstruction and similarities to neutrophilic asthma in humans. As an extrinsic stimulus, hay dust exposure is a major risk factor and induces acute exacerbation in susceptible horses. However, single inducing agents of SEA have hardly been identified on a molecular basis. () is a common mold species in hay and has been described as a major provoking agent of SEA. Unassigned: Aiming to identify disease-relevant antigens, we analyzed using an immunoproteomics approach on two-dimensional ...
The Effect of Repeated Blood Harvesting from Pregnant Mares on Haematological Variables.
Animals : an open access journal from MDPI    February 28, 2024   Volume 14, Issue 5 doi: 10.3390/ani14050745
Oddsdóttir C, Jónsdóttir HK, Sturludóttir E, Vilanova XM.Studies have been carried out on the effect of large-volume blood harvesting from horses, but they were performed on nonpregnant horses of various breeds other than Icelandic horses. This study aimed to investigate the effect on the haematological variables indicating erythropoiesis of repeated blood harvesting from pregnant mares. To account for regional variation, two herds of mares were chosen, both kept under free-range conditions. Sequential EDTA blood samples were collected weekly from 160 mares and analysed for haematological variables in an automated analyser. Serum samples from 115 ma...
Exposure to chemical pollutants and biological aerosol in indoor facilities for recreational and sport horses.
BMC veterinary research    February 28, 2024   Volume 20, Issue 1 78 doi: 10.1186/s12917-024-03930-2
Rodzyń I, Karpińska K, Bis-Wencel H, Wlazło Ł, Ossowski M, Strzelec K, Jaguszewski S, Nowakowicz-Dębek B.Due to the increasing prevalence of equine non-infectious respiratory disease, the air contamination in equine housing (Stables A-C) and training facilities (indoor riding arenas A - C) was investigated. The aim of the study was to monitor gaseous pollutants, bioaerosols, and dust concentrations at three different sites (stables and riding halls), where different floor materials were used in the riding halls. Methods: Air quality was monitored in housing for horses and in riding halls in terms of dust concentration, the presence of gaseous chemical pollutants, and concentrations of biological ...
Equine Models of Temporomandibular Joint Osteoarthritis: A Review of Feasibility, Biomarkers, and Molecular Signaling.
Biomedicines    February 28, 2024   Volume 12, Issue 3 542 doi: 10.3390/biomedicines12030542
Jasiński T, Turek B, Kaczorowski M, Brehm W, Skierbiszewska K, Bonecka J, Domino M.Osteoarthritis (OA) of the temporomandibular joint (TMJ) occurs spontaneously in humans and various animal species, including horses. In humans, obtaining tissue samples is challenging and clinical symptoms appear late in the disease progression. Therefore, genetically modified, induced, and naturally occurring animal models play a crucial role in understanding the pathogenesis and evaluating potential therapeutic interventions for TMJ OA. Among the naturally occurring models, the equine TMJ OA model is characterized by slow, age-related progression, a wide range of clinical examinations, and ...
Effect of β-alanine on the athletic performance and blood amino acid metabolism of speed-racing Yili horses.
Frontiers in veterinary science    February 28, 2024   Volume 11 1339940 doi: 10.3389/fvets.2024.1339940
Li X, Ma J, Li H, Li H, Ma Y, Deng H, Yang K.The objective of this study was to examine the effects of supplemental β-alanine feeding on the athletic performance of Yili horses involved in speed racing, focusing on alterations in plasma free amino acid patterns pre and post exercise. Additionally, the research aimed to evaluate the effects of carnosine on the plasma acid-base buffering capacity and antioxidant levels in these horses. Twelve Yili horse stallions, averaging 3 years in age and 346.50 ± 21.39 kg in weight, were chosen and randomly divided into two groups: a control group and a test group, each comprising six horses...
Current Understanding of Equine Gut Dysbiosis and Microbiota Manipulation Techniques: Comparison with Current Knowledge in Other Species.
Animals : an open access journal from MDPI    February 28, 2024   Volume 14, Issue 5 doi: 10.3390/ani14050758
Boucher L, Leduc L, Leclère M, Costa MC.Understanding the importance of intestinal microbiota in horses and the factors influencing its composition have been the focus of many studies over the past few years. Factors such as age, diet, antibiotic administration, and geographic location can affect the gut microbiota. The intra- and inter-individual variability of fecal microbiota in horses complicates its interpretation and has hindered the establishment of a clear definition for dysbiosis. Although a definitive causal relationship between gut dysbiosis in horses and diseases has not been clearly identified, recent research suggests ...
Automated Spectrophotometric Assays for the Measurement of Ammonia and Bicarbonate in Saliva of Horses: Analytical Validation and Changes in Equine Gastric Ulcer Syndrome (EGUS).
Metabolites    February 28, 2024   Volume 14, Issue 3 doi: 10.3390/metabo14030147
Muñoz-Prieto A, Llamas-Amor E, Contreras-Aguilar MD, Ayala I, Martín Cuervo M, Cerón JJ, Hansen S.Ammonia (NH3) and bicarbonate (HCO3) have been related to gastric ulcers in humans. Ammonia is considered a possible cause of gastric ulcers, whereas bicarbonate has a protective function. The presence of ulcers in the stomach of horses is defined as Equine Gastric Ulcer Syndrome (EGUS), which is a frequent disease in this species, and it has been associated with changes in saliva composition, such as in analytes related to inflammation, immune system and oxidative stress. The objectives of this study were (1) to perform an analytical validation of two automated spectrophotometric assays, one ...
Evaluation of bronchoalveolar lavage fluid from donkeys using four different cytological stains: a pilot study.
Journal of equine veterinary science    February 27, 2024   105035 doi: 10.1016/j.jevs.2024.105035
Vitale V, Bindi F, Briganti A, Bonelli F, Parietti C, Sgorbini M.Bronchoalveolar lavage fluid (BALF) cytology is used for the diagnosis of non-infectious lower airway inflammation in equids. Discrepancies have been reported in the differential cell count when different staining methods were used both in humans and horses. The objective of this study was to compare the results of BALF cytology in donkeys using four different staining methods: modified May-Grunwald Giemsa (mMGG), Diff-Quick (DQ), Toluidine blue (TB) and Perls Prussian blue (PPB). Nine healthy Amiata female donkeys were enrolled. The BAL procedure was performed as previously described and pair...
Comparison of plasma l-lactate between jugular and cephalic veins in healthy and systemically ill horses using a point-of-care device.
Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001)    February 27, 2024   doi: 10.1111/vec.13364
Rhodes AD, Wilkins PA, McCoy AM.To compare plasma l-lactate (LAC) values between samples collected from jugular and cephalic venipuncture in healthy horses and systemically ill horses. Methods: Prospective, experimental study. Methods: Large animal university teaching hospital. Methods: Thirty healthy adult university-owned horses and 43 client-owned horses presenting to the large animal hospital for elective surgical procedures or for emergent medical evaluation of systemic illness. Methods: Blood samples were collected from the jugular vein (JV) and cephalic vein (CV) and placed in EDTA blood tubes prior to any medical the...
Cytokine mRNA expression in the bronchoalveolar lavage cells from horses affected by different equine asthma subtypes.
Journal of equine veterinary science    February 27, 2024   Volume 135 105033 doi: 10.1016/j.jevs.2024.105033
Equine asthma (EA) is a respiratory syndrome associated with the increase of different leukocyte populations in the bronchoalveolar lavage fluid (BALF). Its pathogenetic mechanisms remain unclear. This study aimed to evaluate the associations between the mRNA expression of different cytokines in the BALF, different EA subtypes and lung function. Fifteen horses underwent physical examination, airway endoscopy, BALF cytology and lung function testing (8/15). One horse did not have evidence of EA and was used as healthy reference, while the others were classified as affected by neutrophilic or mi...
Evidence for dopamine production and distribution of dopamine D2 receptors in the equine gastrointestinal mucosa and pancreas.
PloS one    February 27, 2024   Volume 19, Issue 2 e0298660 doi: 10.1371/journal.pone.0298660
Galinelli NC, Bamford NJ, de Laat MA, Sillence MN, Harris PA, Bailey SR.Insulin dysregulation in horses is characterised by hyperinsulinaemia and/or tissue insulin resistance and is associated with increased risk of laminitis. There is growing evidence in other species that dopamine attenuates insulin release from the pancreas; however, this has yet to be examined in horses. The present study aimed to identify whether there are cells capable of producing or responding to dopamine within the equine gastrointestinal mucosa and pancreas. Tissue samples were collected from the stomach, small and large intestines, and pancreas of six mature horses following euthanasia....
Effect of Exercise Conditioning on Countering the Effects of Obesity and Insulin Resistance in Horses-A Review.
Animals : an open access journal from MDPI    February 26, 2024   Volume 14, Issue 5 doi: 10.3390/ani14050727
Pratt-Phillips S.Obesity is an important health concern in horses, along with humans and companion animals. Adipose tissue is an inflammatory organ that alters the insulin-signaling cascade, ultimately causing insulin dysregulation and impaired glucose metabolism. These disruptions can increase the risk of metabolic disease and laminitis in horses and may also impact energy metabolism during exercise. A single bout of exercise, along with chronic exercise conditioning, increases insulin sensitivity and glucose disposal via both contraction- and insulin-mediated glucose uptake pathways. Regular exercise also in...
Effect of leukoreduction on the metabolism of equine packed red blood cells during refrigerated storage.
Journal of veterinary internal medicine    February 26, 2024   doi: 10.1111/jvim.17015
Miglio A, Rocconi F, Cremonini V, D'Alessandro A, Reisz JA, Maslanka M, Lacroix IS, Tiscar G, Di Tommaso M, Antognoni MT.Understanding of the biochemical and morphological lesions associated with storage of equine blood is limited. Objective: To demonstrate the temporal sequences of lipid and metabolic profiles of equine fresh and stored (up to 42 days) and leukoreduced packed red blood cells (LR-pRBC) and non-leukoreduced packed RBC (nLR-pRBC). Methods: Packed RBC units were obtained from 6 healthy blood donor horses enrolled in 2 blood banks. Methods: Observational study. Whole blood was collected from each donor using transfusion bags with a LR filter. Leukoreduction pRBC and nLR-pRBC units were obtained an...
Impact of Aspergillus fumigatus inoculation on the composting of wood shavings bedding for horses.
Letters in applied microbiology    February 26, 2024   ovae023 doi: 10.1093/lambio/ovae023
do Nascimento AGCR, de Paula AM, Busato JG, da Rocha GC, Perecmanis S, da Silva SG, Neto ART.Equine farming generates a significant amount of waste, prompting the need for effective management. Composting enhanced by filamentous fungi holds promise for this purpose. This study focused on inoculating Aspergillus fumigatus isolates in composting horse bedding made with wood shavings (Pinus elliottii) The experiment lasted 90 days, with two treatment groups, control and inoculated, analyzing temperature, pH, electrical conductivity, total organic carbon and nitrogen content, cellulose, hemicellulose and lignina contents. Both treatments entered the thermophilic phase by the fourth day, r...
Safety assessment of equine allogeneic tenogenic primed mesenchymal stem cells in horses with naturally occurring tendon and ligament injuries.
Frontiers in veterinary science    February 26, 2024   Volume 11 1282697 doi: 10.3389/fvets.2024.1282697
Carlier S, Depuydt E, Van Hecke L, Martens A, Saunders J, Spaas JH.Mesenchymal stem cells provide a valuable treatment option in orthopedic injuries in horses. Unassigned: The aim of this study was to evaluate the hematological, biochemical, immunological and immunomodulatory parameters following intralesional treatment with tenogenic primed equine allogeneic peripheral blood-derived mesenchymal stem cells (tpMSCs) in client-owned horses with naturally occurring superficial digital flexor tendon (SDFT) and suspensory ligament (SL) injuries. Unassigned: The immunogenicity and immunomodulatory capacities of tpMSCs were assessed in a modified mixed lymphocyte re...
Morphological evidence of a potential arrhythmogenic substrate in the caudal and cranial vena cava in horses.
Equine veterinary journal    February 23, 2024   doi: 10.1111/evj.14075
Ibrahim L, Buschmann E, van Loon G, Cornillie P.Three-dimensional electro-anatomical mapping, previously performed in horses with atrial arrhythmias, has demonstrated the medial region of the caudal vena cava (CaVC), 1-8 cm caudal to the fossa ovalis, as an anatomical predilection site for atrial tachycardia associated with areas of slow conduction and conduction block. Slow conduction has also been recorded in the cranial vena cava (CrVC). Objective: To investigate the morphological characteristics of the myocardial sleeves (MS) in the CaVC and CrVC, in order to identify a potential substrate of right sided atrial arrhythmias. Methods: C...
Neutrophil extracellular traps and active myeloperoxidase concentrate in lamellar tissue of equids with naturally occurring laminitis.
Veterinary immunology and immunopathology    February 23, 2024   Volume 270 110738 doi: 10.1016/j.vetimm.2024.110738
Storms N, de la Rebière G, Franck T, Mouithys Mickalad A, Sandersen C, Ceusters J, Serteyn D.Laminitis is a pathology of the equine digit ultimately leading to a failure of the dermo-epidermal interface. Neutrophil activation is recognized as a major factor in SIRS-associated laminitis and has recently been described in induced endocrinopathic laminitis evidenced by the presence of myeloperoxidase (MPO). Neutrophil extracellular traps (NET) are released with neutrophil activation. This study aimed to investigate the presence and activity of MPO and NET in the lamellar tissue of equids presented with naturally occurring laminitis. Samples of lamellar tissue of five horses and five donk...
Advances in the Clinical Diagnostics to Equine Back Pain: A Review of Imaging and Functional Modalities.
Animals : an open access journal from MDPI    February 23, 2024   Volume 14, Issue 5 doi: 10.3390/ani14050698
Domańska-Kruppa N, Wierzbicka M, Stefanik E.Back pain is common in ridden horses. Back diseases in horses include Impinging Dorsal Spinous Processes, Ventral Spondylosis, Osteoarthritis of Articular Process, Intervertebral Discs Disease, Vertebral Fractures, Conformational Abnormalities, Desmopathy of the Supraspinous Ligament, Desmopathy of the Intraspinous Ligament, and Longissimus Muscle Strain. Back pain may also develop as a result of lameness (particularly hindlimb lameness). A poorly fitting saddle and an unbalanced rider are also considered important factors influencing the development of back pain in horses. The conventional di...
microRNAs are differentially expressed in equine plasma of horses with osteoarthritis and osteochondritis dissecans versus control horses.
PloS one    February 23, 2024   Volume 19, Issue 2 e0297303 doi: 10.1371/journal.pone.0297303
Antunes J, Salcedo-Jiménez R, Lively S, Potla P, Coté N, Dubois MS, Koenig J, Kapoor M, LaMarre J, Koch TG.Osteoarthritis (OA) is a leading cause of lameness in horses with no effective disease-modifying treatment and challenging early diagnosis. OA is considered a disease of the joint involving the articular cartilage, subchondral bone, synovial membrane, and ligaments. Osteochondritis dissecans (OCD) is a joint disease consisting of focal defects in the osteochondral unit which may progress to OA later in life. MicroRNAs (miRNAs) have been recognized as small non-coding RNAs that regulate a variety of biological processes and have been detected in biological fluids. MiRNAs are currently investiga...
Vesicular Stomatitis Virus.
The Veterinary clinics of North America. Food animal practice    February 23, 2024   Volume 40, Issue 2 251-259 doi: 10.1016/j.cvfa.2024.01.005
Pelzel-McCluskey AM.Vesicular stomatitis (VS) is a vector-borne livestock disease caused by either VS New Jersey virus or VS Indiana virus. The disease circulates endemically in northern South America, Central America, and Mexico and only occasionally causes outbreaks in the United States. During the past 20 years, VS outbreaks in the southwestern and Rocky Mountain regions occurred periodically with incursion years followed by virus overwintering and subsequent expansion outbreak years. Regulatory response by animal health officials prevents spread from lesioned animals and manages trade impacts. Recent US outb...
Influence of screw configuration on reduction and stabilization of simulated complete lateral condylar fracture in equine limbs.
Veterinary surgery : VS    February 21, 2024   doi: 10.1111/vsu.14077
Brabon A, Hughes KJ, Jensen K, Xie G, Labens R.To determine the influence of screw configuration on the reduction and stabilization of simulated complete lateral condylar fracture. Methods: Randomized experimental crossover study. Methods: A lateral condylar fracture was simulated in 18 cadaver limbs from nine horses. Each limb underwent repair with 4.5 mm diameter cortex screws, tightened to 4 Nm, in a linear and triangular configuration. Computed tomography (CT) of each repair was performed with the limbs in unloaded and loaded conditions. Fracture gaps were measured at the dorsal, palmar, and middle locations of the third metacarpal c...
Intralesional interferon alpha-2b as a novel treatment for periocular squamous cell carcinoma in horses.
PloS one    February 21, 2024   Volume 19, Issue 2 e0297366 doi: 10.1371/journal.pone.0297366
Martabano BB, Dow S, Chow L, Williams MMV, Mack MK, Bellone R, Wotman KL.To determine the safety and efficacy of perilesional human recombinant interferon alpha-2b (IFNα2b) for treatment of periocular squamous cell carcinoma (PSCC) in horses. Methods: Eleven horses (12 eyes) with PSCC were enrolled in this prospective clinical study with owner consent. Methods: Systemically healthy horses were included in the study following confirmation of PSCC via biopsy. Every two weeks for a maximum of six treatments, horses were sedated and perilesional injection of IFNα2b (10 million IU) was performed. Tumors were measured prior to each injection and at one, three, and 12 m...
1 4 5 6 7 8 1,526