An investigation into the occurrence of, and risk factors for, concurrent suspensory ligament injuries in horses with hindlimb proximal suspensory desmopathy

Hindlimb proximal suspensory desmopathy (PSD) is a common cause of lameness or poor performance in horses and may occur alone or together with other suspensory ligament (SL) injuries in forelimbs or hindlimbs. The aims of this retrospective case-control study (January 2009 to December 2018) were to describe the occurrence of, and identify risk factors for, concurrent SL injuries in horses with hindlimb PSD. Data concerning age, breed, sex, work discipline, height, bodyweight and work history were collected. Concurrent SL injuries were defined as forelimb proximal suspensory desmitis or SL branch injuries (>= grade 2 [0-3]) in any limb. Hindlimb PSD was graded mild, moderate or severe based on ultrasonography. Data were described, and multivariable logistic regression modelling was used to identify factors associated with concurrent SL injuries. Data were available for 923 horses with hindlimb PSD, 28.6% (n = 264) of which had concurrent SL injuries. Age category (= 6 years of age; P = 0.008), bodyweight:height ratio (P = 0.001), breed (P = 0.05), symmetry vs. asymmetry of hindlimb PSD ultrasonography grade (P = 0.005) and asymmetry vs. symmetry of lameness grade (P = 0.02) were associated with concurrent SL injury in horses with hindlimb PSD. Compared with horses aged >= 6 years, younger horses (odds ratio [OR] 1.76; 95% confidence interval [CI] 1.2-2.7) were more likely to have concurrent SL injury. The risk for concurrent SL injuries increased for every unit increase in bodyweight:height ratio (OR 2.27; CI 1.4-3.7). Compared with Thoroughbred crosses, Warmblood crosses (OR 3.3, CI 1.4-7.8), Thoroughbreds (OR 2.9, CI 1.1-7.1) and Irish Draught Horses (OR 3.5, CI 1.3-9.9) were more likely to have concurrent SL injuries. Hindlimb PSD ultrasonography grade severity was not associated with concurrent SL injury. In conclusion, age, bodyweight:height ratio and breed influenced the risk for concurrent lesions of the SL ligament. Further prospective studies in young horses are warranted

Desmopatia degenerativa em equinos: métodos de diagnóstico em animais vivos

A desmopatia degenerativa (DD) possui caráter sistêmico e manifesta-se por acúmulos de proteoglicanos (PG) na matriz extracelular (MEC) de tecidos que contenham colágeno. Este estudo teve o objetivo de diagnosticar equinos suspeitos de serem acometidos por DD, em um plantel de animais de raça nacional, segundo o ângulo da articulação metatarsofalangiana (AMF) e a presença de acúmulos de PG em amostras de ligamento da nuca (LN). Analisaram-se 123 equinos clinicamente sadios e somente três (2,7%) deles, segundo o ângulo AMF < 146(0), foram considerados suspeitos. Não houve diferença significativa entre os grupos. Quinze éguas foram submetidas ao exame do ângulo da AMF e à biópsia do LN, das quais sete (47,7%) foram consideradas suspeitas, segundo ângulo da AMF, enquanto seis (40%) apresentaram acúmulos de PG. Foram encontrados acúmulos de PG em três (20%) éguas não suspeitas. Um animal suspeito não apresentou alterações histológicas compatíveis de DD

Physicochemical and structural factors in the sulfuric acid leaching of nickel- and copper-bearing synthetic birnessites

A large number of nickel- and copper-doped samples of birnessite (0.7 nm phase), a layered-structure manganese mineral, were synthesized by dehydration of respective buserites (1 nm phase). The samples were characterized in terms of chemical composition, specific surface area, phase constituents, crystallinity, strain, morphological features, and structural complexity, in order to study the influence of the physicochemical characteristics of the samples on the leachability of doped elements and manganese in sulfuric acid. In contrast to manganese, the leaching behavior of doped nickel and copper is found to be more sensitive to the structural characteristics of the host birnessite phase. The leachability of the doped elements does not show any correlation with the specific surface area of the samples. Significant parameters affecting leachability are the interlayer spacing of the parent buserite phase used in the synthesis and the microcrystalline dimension and strain in the 〈001〉 crystallographic direction of the birnessite phase. In addition, leachability is also controlled by the crystal field stabilization energy (CFSE) of the doped metal ion. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies on leach residues indicated the transformation of birnessite phase into other minerals such as nsutite (γ-MnO2). A significant fraction of the doped nickel and copper (20 to 40 pct) remains unleached, even after prolonged leaching up to 6 days, and this is attributed to the compact structure of the newly formed phases during leaching

Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability1. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals2, 3, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk4. Modestly powered genome-wide association studies (GWAS)5, 6, 7, 8, 9, 10 have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility11. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis