The Health Status of Horses Used for at Least Six Complete Cycles of Loxoscelic Antivenom Production.

Antivenom production against Loxosceles venom relies on horses being immunized and bled for plasma harvest. One horse can partake in several cycles of antivenom production, which will require years of constant venom and adjuvant inoculation and bleeding. The actual impact on the health of horses that participate in several antivenom-producing cycles is unknown. Therefore, this study aimed to evaluate the general health status of horses that underwent at least six cycles of loxoscelic antivenom production. Seven crossbred horses that had partaken in six to eight complete antivenom-producing cycles were used and established as the immunized group (IG). Under the same handling and general management, eleven horses were established as the control group (CG). The horses were evaluated regarding their general clinical status and had their blood sampled, and an ECG recorded. The IG presented lower RBC and PCV, despite keeping values within inferior limits for the species. Renal function was not impaired, and liver-related enzymes were higher than those in the CG, probably due to liver exertion from immunoglobulin synthesis. ECG showed some abnormalities in the IG, such as atrioventricular block and a wandering atrial pacemaker, corroborated by an increase in CK-MB. The cardiovascular abnormalities were mainly found in the horses that participated in several antivenom-producing cycles. The overall results indicate that these horses had some impairment of their general health status. Once available, some alternative, less toxic antigens should replace the venom for immunization of horses used for antivenom production.

Clinical Effects of the Immunization Protocol Using Loxosceles Venom in Naïve Horses.

Bites of brown spiders (Loxosceles spp.) are responsible for dermonecrotic lesions and potentially systemic envenoming that can lead to death. The only effective therapy is the use of the antivenom, usually produced in horses. However, little is known about the consequences of the systematic use of the Loxosceles venom and adjuvants and of the bleedings on antivenom-producing horses. Thus, the aim of this study was to evaluate the clinical changes in horses in their first immunization protocol for Loxosceles antivenom production. Eleven healthy horses, never immunized, were evaluated in three different periods: T0 (before immunization); T1 (after their first venom immunization); and T2 (after their first bleeding). Horses were clinically evaluated, sampled for blood, and underwent electrocardiographic (ECG) recordings. Several suppurated subcutaneous abscesses occurred due to the use of Freund's adjuvants and thrombophlebitis due to systematic venipunctures for the bleeding procedures. ECG showed arrhythmias in few horses in T2, such as an increase in T and R waves. In summary, the immunization protocol impacted on horses' health, especially after bleeding for antivenom procurement.

History, challenges and perspectives on Loxosceles (brown spiders) antivenom production in Brazil.

Antivenom is the only effective therapy for treating any envenomation. Despite its obvious public health importance, the laborious process of procuring, distributing and controlling the quality of such immunobiologicals is being neglected. Brazil is fully self-sufficient in the production of antivenoms. Since the 1950s, Loxoscelism, a syndrome with an onset after a spider bite from specimens of the Loxosceles genus occurs, is considered a public health issue. The Brazilian history in developing antivenom therapy, its production hindrances, and other challenges are discussed in this paper, as well as some promising novelties that can improve production and processing of Loxosceles antivenom.

Anaplasma phagocytophilum direct detection and exposure evidence in equines from two breeding farms from Minas Gerais State, Brazil / Detecção direta e evidência da exposição a Anaplasma phagocytophilum em equinos de dois haras em Minas Gerais, Brasil

Equine granulocytic anaplasmosis is caused by Anaplasma phagocytophilum, a gram negative, obligatory intracellular bacterium, member of Anaplasmataceae family, included in the Rickettsiales order. Little is known about the disease, transmission dynamics, genetic diversity and prevalence in Minas Gerais state, Brazil. This work aimed to do a serosurvey using indirect immunofluorescent assay (IFA) test and evaluation of buffy coat smears, and nested polymerase chain reaction (PCR) as diagnostic methods, to determine the disease situation in horses from two manga-larga marchador breeding farms located in the municipalities of Ataléia e São Vicente de Minas, in Minas Gerais state. It was found that 76% (131/172) of the animals were considered reactive for IFA test, and the total of 12.8% was positive at buffy coat smears analysis. At PCR analysis, it was found 1.94% of the samples positive to the infection. Those samples were sequenced and showed 96% of similarity to A. phagocytophilum from a Ixodes ricinus tick. There is a high frequency of animals with the evidence of contact to A. phagocytophilum on the two evaluated properties in this study, which was proved by positiveness in PCR analysis. New researches must be carried out to better understand the epidemiologic and clinical dynamic of the disease in the state of Minas Gerais.(AU)

A anaplasmose granulocítica equina é causada por uma bactéria gram-negativa, intracelular obrigatória, membro da família Anaplasmataceae, incluída na ordem Rickettsiales e denominada de Anaplasma phagocytophilum. Pouco se sabe sobre a doença, sua dinâmica de transmissão, diversidade genética e prevalência em Minas Gerais, Brasil. Este trabalho teve por objetivo realizar o levantamento sorológico utilizando a reação de imunofluorescência indireta, avaliação direta de capa leucocitária e nested reação em cadeia da polimerase (PCR) como métodos diagnósticos, a fim de avaliar a situação da doença em dois haras de criação de cavalos manga-larga marchador localizados nas cidades de Ataléia e São Vicente de Minas, no estado de Minas Gerais. Foi encontrada prevalência de 76% (131/172) de animais reativos para a reação de imunofluorescência indireta, quando todos os animais das duas propriedades e das duas coletas foram agrupados, e 12,8% dos animais foram positivos na avaliação da capa leucocitária. A reação de imunofluorescência indireta detectou 1,94% das amostras como positivas para o agente. Essas amostras foram submetidas ao sequenciamento de nucleotídeos, e foi observada similaridade de 96% com A. phagocytophilum proveniente de carrapatos Ixodes ricinus. Existe alta prevalência de animais positivos para a infecção por A. phagocytophilum, o que foi provado pela positividade dos animais à PCR. Novas pesquisas devem ser conduzidas a fim de entender a dinâmica epidemiológica e clínica da doença no estado de Minas Gerais.(AU)

Could mesenchymal stem cell therapy help in the treatment of muscle damage caused by Bothrops alternatus venom? / Podem as células tronco mesenquimais auxiliarem no tratamento da lesão muscular causada pelo veneno de Bothrops alternatus?

ABSTRACT: The aim of this study was to evaluate the use of mesenchymal stem cells (MSC) in the treatment of myonecrosis induced by Bothrops alternatus venom in rats. Seventy-five male adult Wistar rats were divided into three experimental groups. G1 and G2 were injected in the gastrocnemius muscle with 120μg of B. alternatus venom, while G3 received 200μL of PBS only. Three days after the venom injection, 12 rats from G1 were treated with 5.0 x 106 MSC in PBS, whereas G2 and G3 rats received PBS. Every three days, blood and muscle samples of five animals from each group were taken for serum biochemical and pathological analyses. Histological examinations showed more intense muscle lesions following MSC treatment, characterized by disorganization and loss of muscle fibers, with focal necrosis and inflammatory infiltration by mononuclear cells. In conclusion, the use of MSC for the treatment of local damage caused by inoculation of B. alternatus venom impaired muscle regeneration and interfered in the healing process.

RESUMO: O objetivo do presente trabalho foi avaliar a utilização das células tronco mesenquimais (MSC) no tratamento da mionecrose induzida pelo veneno de Bothrops alternatus em ratos. 75 ratos Wistar adultos foram distribuídos em três grupos experimentais. G1 e G2 receberam 120μg de veneno de B. alternatus, enquanto o G3 recebeu apenas 200μL de PBS. Três dias após a administração do veneno, os ratos do grupo G1 foram tratados com 5.0 x 106 MSC, enquanto G2 e G3 receberam exclusivamente PBS. A cada três dias, amostras de sangue e tecido muscular foram coletadas de cinco animais de cada grupo para avaliação bioquímica sérica e patológica, respectivamente. A análise histológica revelou lesão muscular mais intensa após a aplicação das MSC, caracterizada pela desorganização e perdas das fibras musculares, com necrose focal e infiltrado inflamatório mononuclear. É possível concluir que a utilização das MSC para o tratamento da lesão local causada pela inoculação do veneno B. alternatus deteriorou a regeneração muscular e interferiu com o processo de cicatrização.

Morfologia de potros da raça Brasileiro de Hipismo / Morphology of Brasileiro de Hipismo foals

Objetivou-se avaliar a morfologia de potros da raça Brasileiro de Hipismo, utilizando análise de imagens digitais e medidas de perímetros corporais para estimativa de índices corporais dos animais. As mensurações lineares e angulares foram obtidas utilizando imagens digitais dos potros com câmera acionada pelo aplicativo Simi Reality Motion Systems®. As medidas foram baseadas em pontos anatômicos realçados com 19 marcadores reflexivos. A análise estatística descritiva dos resultados foi realizada utilizando o programa SAS. Os potros estavam em crescimento, com aumento das medidas lineares de altura na cernelha e na garupa, comprimento do corpo, distância escápulo-metacarpofalângica e nos comprimentos do pescoço, da perna e do antebraço. Os ângulos úmero-radial, metacarpo-falângico, fêmoro-tibial, tíbio-metatarsico aumentaram com a idade, enquanto que os ângulos da cabeça, do pescoço, coxo-femoral, metatarso-falângico, escápulo-solo e coxo-solo foram variáveis entre os momentos de avaliação. Os potros foram classificados em mediolíneos e hipermétricos pelos índices Corporal e Dáctilo-torácico, respectivamente. A avaliação do crescimento dos potros foi possível através da imagem digital.

This research aimed to evaluate the morphology of Brasileiro de Hipismo foals using digital image analysis and girth measurements to estimate body indexes of animals. The linear and angular measurements were obtained by digital images of the foals with camera triggered by Simi Reality Motion Systems®. The measures were based on anatomical landmarks highlighted with 19 reflective markers. A descriptive statistical analysis of the results was performed using the SAS program. The foals were growing, with increased linear measurements of height at withers and croup, body length, distance from shoulder-fetlock and neck length, leg length and forearm length. The angles humerus-radial, metacarpal-falangeano, femoro-tibial, tibio-metatarsal increased with age, whiles the angles of the head, neck, coxofemoral, metatarsal-falangeano, shoulder-floor and coxae-floor were variable among the periods. The foals were classified as medium shape and hypermetric by Corporal Index, Dactilo-thoracic Index, respectively. Assessment of growth of the foals was possible through a digital image.