Charged-particle chaotic dynamics in rotational discontinuities.

The interplanetary plasma is characterized by a high level of complexity over a broad range of spatial scales. Spacecraft have detected a large variety of embedded structures that have been identified as discontinuities in the magnetic field vector. They can be either generated within the solar corona and advected by the plasma flow or locally generated as a result of the turbulent cascade of the solar wind turbulence. Since magnetic field fluctuations and structures influence the energetic particle propagation, here we set up a numerical model to study the interaction between charged particles and an ideal magnetohydrodynamics rotational discontinuity. This interaction is strongly influenced by the model parameters, such as the rotation angle of the discontinuity, the orientation of the mean-field direction with respect to the normal to the discontinuity direction, the initial particle pitch angle, and the initial particle gyrophase. Numerical results clearly show that the motion of particles crossing the discontinuity is extremely complex and highly sensitive to the initial conditions of the system, with transitions to a chaotic behavior. We find that particles can be temporarily trapped in rotational discontinuity and that the trapping times have a nearly power-law distribution. Also, the separatrix in the initial conditions phase space between crossing and noncrossing trajectories has a fractal structure. Implications for energetic particle propagation in space plasmas are discussed.

Retrospective study of radiographic changes in athletic bulls with orthopedic disorders / Estudo retrospectivo das alterações radiográficas de touros atletas com doenças ortopédicas

The objectives of this study were to demonstrate the lesions that affect athlete bulls and to correlate the disorders with weight, age, affected limb and region of the limb. The present study was accomplished using radiographic images of athletic rodeo bulls collected from the medical and surgical records of the large animal service at the veterinary hospital. Radiographic images were evaluated for 136 bulls that were taken care of at the Veterinary Hospital, ranging in age from 4 to 13 years, with an average weight of 800kg and proven prior physical activity through participation in rodeos. The chi-square or Fisher's exact test was used to assess the association between the studied variables. It was observed that 71.6% of the bulls studied and suffering from lameness had radiographic lesions, predominantly in experienced animals. Enthesopathy in starter and experienced bulls, septic arthritis in starter bulls, and fractures and degenerative joint disease in experienced bulls were the most frequent radiographic lesions diagnosed. The region of limb where the majority of radiographic changes occurred was the digits. Risk factors and occurrence of diseases of the locomotor system in athletic bulls are similar to those in sport equines.(AU)

O objetivo desse trabalho foi demostrar quais lesões acometem touros atletas, correlacionando as desordens com peso, idade, membro e região afetada. O presente estudo foi realizado utilizando radiografias de touros atletas de rodeio, após levantamento dos prontuários clínicos e cirúrgicos do serviço de grandes animais de um hospital veterinário. Foram avaliadas radiografias de 136 touros que haviam sido atendidos em tal hospital, com idade variando de quatro a 13 anos, com média de peso de 800kg e realizavam participação em rodeios. Para avaliar a associação entre as variáveis estudadas foi utilizado o teste exato de Fischer e o Qui-quadrado. Observou-se que 71,6% dos touros estudados que claudicavam, apresentavam lesões radiográficas, predominantemente em animais mais experientes. A entesiopatia em todos os animais, artrite séptica nos touros iniciantes, fraturas e doença articular degenerativa nos touros mais experientes, foram as alterações radiográficas mais frequentes. As regiões com maior ocorrência de lesões radiográficas foram os dígitos. Os fatores de risco para ocorrência de doenças no sistema locomotor de touros atletas são diversos, similares aos que ocorrem nos equinos atletas.(AU)

Turbulence-Driven Ion Beams in the Magnetospheric Kelvin-Helmholtz Instability.

The description of the local turbulent energy transfer and the high-resolution ion distributions measured by the Magnetospheric Multiscale mission together provide a formidable tool to explore the cross-scale connection between the fluid-scale energy cascade and plasma processes at subion scales. When the small-scale energy transfer is dominated by Alfvénic, correlated velocity, and magnetic field fluctuations, beams of accelerated particles are more likely observed. Here, for the first time, we report observations suggesting the nonlinear wave-particle interaction as one possible mechanism for the energy dissipation in space plasmas.

Effect of a constant rate infusion of remifentanil hydrochloride on left ventricular systolic and diastolic function in propofol-anesthetized dogs.

OBJECTIVE To assess the effects of a constant rate infusion (CRI) of remifentanil hydrochloride on left ventricular systolic and diastolic function in healthy propofol-anesthetized dogs. ANIMALS 6 healthy Beagles. PROCEDURES Each dog underwent 2 experimental treatments separated by a 7-day interval. In 1 treatment, anesthesia was induced with propofol and maintained with a CRI of propofol (0.6 mg/kg/min); dogs also received a CRI of saline (0.9% NaCl) solution. In the other treatment, anesthesia was similarly induced and maintained with propofol; dogs also received a CRI of remifentanil (0.3 µg/kg/min). Doppler echocardiographic and hemodynamic variables of interest were determined at baseline (before anesthesia) and at 20, 40, and 60 minutes following the simultaneous start of the 2 CRIs of each treatment; all CRIs were administrated for 60 minutes. RESULTS For the 2 treatments, end-diastolic and end-systolic volume indices did not differ from baseline or at any time point. Peak tissue Doppler-derived mitral annulus systolic velocity decreased from baseline with both treatments; however, no differences were found between treatments at any time point. Mean arterial blood pressure decreased similarly with both treatments. Heart rate and Doppler-determined cardiac index decreased significantly with the propofol-remifentanil treatment, compared with findings for the propofol-saline solution treatment. For the propofol-remifentanil treatment, the ratio of peak velocity flow in early diastole to that in late diastole remained > 1.80, whereas the ratio of early to late Doppler-derived mitral annulus velocity had a normal relaxation pattern. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study indicated that a CRI of remifentanil administered along with a CRI of propofol does not impair left ventricular systolic and diastolic function in healthy dogs.

Does lipid peroxidation and oxidative DNA damage differ in cryopreserved semen samples from young, adult and aged Nellore bulls?

The aims of this study were to evaluate cryopreserved semen of Nellore bulls of different ages and verify whether sperm quality declines with advancing age and whether lipid peroxidation and DNA damage are involved in this process. For this purpose, 40 Nellore bulls were divided into three age groups: Young, aged 1.8-2 years (n = 9); Adult, aged 3.5-7.0 years (n = 19); and Seniors, aged 8.0-14.3 years (n = 12). Three ejaculates were collected from each bull, cryopreserved and evaluated for various parameters including membrane integrity, mitochondrial potential (FITC-PSA and JC1), lipid peroxidation (C-11BODIPY 581 / 591) and oxidative DNA damage (8OHdG) using flow cytometry. The thawed semen of senior bulls was characterized by a low percentage of motile sperm (33.7 ±â€¯6.1%), higher damage to the plasma and acrosomal membrane (37.5 ±â€¯9.8%), and low mitochondrial potential (29.1 ±â€¯13.8%), as well as higher percentages of peroxidated cells (53.6 ±â€¯12.2%) and DNA damage (44.1 ±â€¯11.0%; P < 0.05). Lipid peroxidation was negatively correlated with motility (r = -0.35, P < 0.0002), average mitochondrial potential (r = -0.42; P < 0.0001) and showed a positive correlation with membrane injury and oxidative DNA damage (r = 039; P = 0.0003). Young bulls presented superior thawed sperm quality, possibly due to greater resistance to oxidative stress and, consequently, to cryopreservation. In conclusion, the sperm quality of bull semen declines with advancing age and is strongly associated with increased oxidative damage to both the plasma membrane and DNA.

Serum immunoglobulin from Nellore cattle produced by in vitro fertilization and treated for umbilical diseases / Imunoglobulinas séricas de bovinos Nelore produzidos por fertilização in vitro e tratados para onfalopatias

The aim of this study was to measure serum immunoglobulin concentrations of Nellore cattle produced by in vitro fertilization (IVF) with umbilical diseases and to evaluate surgical excision as a method of treatment. Sixteen cattle with ages ranging from 1 to 15 months, males and females, affected by umbilical diseases were enrolled in the study. Blood samples were collected for cell counts and the determination of immunoglobulin concentrations by electrophoresis and zinc sulphate turbidimetry (ZST). Four calves were presented with umbilical herniation, two with an umbilical herniation associated with a persistent urachus, two with an umbilical herniation with a persistent urachus and omphaloarteritis, three with an umbilical herniation and an urachal diverticulum, three with a persistent urachus, one with an urachal diverticulum, and one with omphalitis. The blood cell counts pre- and post-surgical revealed differences in cell volume and the number of leukocytes. The immunoglobulin values measured by electrophoresis values were below normal in most animals, whereas the ZST showed normal levels in most of them. Most of the calves affected by umbilical diseases and produced by IVF presented hypoglobulinaemia. Correlations between umbilical diseases, failure of passive transfer of immunity and IVF could not be demonstrated.(AU)

Os objetivos desse estudo foram mensurar as concentrações séricas das imunoglobulinas de bovinos Nelore, produzidos por fertilização in vitro (FIV), acometidos por onfalopatias e avaliar a excisão cirúrgica como método de tratamento. Utilizou-se 16 animais, com idade variando de 1 a 15 meses, machos e fêmeas, acometidos por afecções umbilicais. Amostras de sangue foram colhidas para realização de hemogramas e avaliação das imunoglobulinas, por meio de eletroforese e turbidimetria com sulfato de zinco. Foram observados quatro casos de hérnias umbilicais, dois de hérnia umbilical associadas à persistência de úraco, dois casos de hérnia umbilical com persistência de úraco e onfaloarterite, três de hérnia umbilical com divertículo de úraco, três casos de persistência de úraco, um de divertículo de úraco e um de onfalite. O hemograma revelou diferença significativa para os valores de Volume Globular e Leucócitos, nos momentos pré e pós-tratamento cirúrgico dos animais. A eletroforese evidenciou valores de imunoglobulina abaixo da normalidade na maioria dos animais, enquanto que a turbidimetria apresentou níveis normais na maioria dos bovinos, quando comparados com valores de referência. A maioria dos bovinos estudados, acometidos de onfalopatias e concebidos por FIV, apresentaram hipoglobulinemia. Os resultados obtidos não permitem afirmar que existe relação entre as onfalopatias, falha de transferência de imunidade passiva e FIV.(AU)

Factors associated with positivity for canine visceral leishmaniosis in an endemic area in Brazil.

Visceral leishmaniosis (VL) is a public health problem and its occurrence depends primarily on the presence of the vector and susceptible hosts; in the urban environment, the dog is the main reservoir. This study aimed to analyze the distribution of canine visceral leishmaniosis (CVL) and factors associated with it in an urban area endemic for VL. Analysis of the variables was based on 2755 epidemiological records of dogs positive and negative for CVL over a three-year period (2009, 2010 and 2011). A dog was considered positive when it presented amastigotes in the cytological examination of lymph node biopsy and/or was seropositive by immunoenzymatic and indirect immunofluorescence assays. CVL positive dogs were observed throughout the town, but significant differences were observed between the sectors analyzed (P<0.0001), with two sectors showing higher positivity. CVL prevalence was 35.9% and was significantly associated with age and breed (P<0.0001). Concerning symptoms, 44.3% of symptomatic dogs were positive for LV (P<0.0001) in an urban area endemic for this zoonosis.

A study of intestinal parasites in children of an urban region with excellent sanitary condition reveals high occurrence of Blastocystis spp

Intestinal parasites are among the major causative agents of diseases that affect animals and humans, especially children. In view of this, the current study evaluated the occurrence of these parasitic agents in 737 children in an urban region with excellent sanitation condition of the city of Pedreira, São Paulo, Brazil. Fecal samples from the children were processed with the use of a technique of high diagnostic efficiency (TF-Test®). The diagnosis of these samples resulted in the detection of 557 parasitic structures among eleven genera of parasites, and of 46.4% (342/737) infected children. Blastocystis spp. was found in 69.6% (238/342) of the positive samples and the monoparasitism was accompanied by symptoms in 44 children. Furthermore, 67.8% (232/342) of the infected children had close contact with pets, suggesting a possible zoonotic transmission. Lastly, this study allowed to perform health education to the children, aiming the reduction of new intestinal parasitic infections.

Efeitos da corticoterapia materna nos valores hemogasométricos de cordeiros nascidos a termo e prematuros / Effects of maternal blood gas values corticotherapy of Lambs born at term and premature

O objetivo do estudo foi avaliar as variáveis hemogasométricas de cordeiros nascidos a termo e prematuros do nascimento às 48 horas de vida. Foram constituídos quatros grupos experimentais: PN (cordeiros nascidos de parto normal, n=15, média de 146 dias de gestação); PNDEX (cordeiros nascidos de parto normal, cujas mães receberam 16 mg de dexametasona aos 141 de gestação, n=8, média de 143 dias de gestação); PRE (cordeiros prematuros nascidos de cesarianas aos 138 dias de gestação, n=10) e PREDEX (cordeiros prematuros nascidos de cesarianas aos 138 dias de gestação, cujas mães receberam 16 mg de dexametasona dois dias antes do parto, n=9). Imediatamente após o nascimento, os cordeiros de todos os grupos apresentaram quadro de acidose respiratória (pH baixo e pCO2 elevada), com maior ênfase nos animais prematuros. A concentração de HCO3 - diminuiu entre 15 e 60 minutos de vida, principalmente nos grupos PRE e PREDEX, com posterior aumento no M24h. Os valores de diferença de base foram menores nos cordeiros prematuros, os quais apresentaram respiração abdominal, intensa dispneia e grande quantidade de líquido pulmonar. A estabilização do equilíbrio ácidobase ocorreu em todos os animais ao longo das primeiras 24 horas de vida. A dexametasona teve influência positiva sobre a condição clínica dos animais prematuros, resultando em adequada ventilação e perfusão tecidual, o que garantiu maior taxa de sobrevivência.(AU)

The aim of the study was to evaluate blood gas parameters of full-term and premature lambs from birth to 48 hours of life. Four experimental groups were formed: NDG (normal delivery group - lambs vaginally delivered, n=15, average of 146-day gestation); NDEXG (normal delivery with dexamethasone group - lambs vaginally delivered whose mothers received 16 mg of dexamethasone at 141 days of gestation, n=8, average of 143-day gestation); PRE (premature lambs born by cesarean section at 138 days of gestation, n=10) and PREDEX (premature lambs born by cesarean section at 138 days gestation, whose mothers received 16mg of dexamethasone two days before, n=9). Immediately after birth, lambs from all groups showed respiratory acidosis (low pH and high pCO2), most obviously in premature animals. The concentration of HCO3 - was lower between 15 and 60 minutes of life, especially in PRE and PREDEX groups with subsequent increase in M24h. The values of base excess were lower in premature lambs, which showed abdominal breathing, severe dyspnea and lots of lung fluid. The stabilization of acid-base balance occurred in all animals during the first 24 hours of life. Dexamethasone had a positive effect on the clinical condition of the premature lambs, resulting in adequate ventilation and tissue perfusion, which guaranteed higher survival rate.(AU)

Effects of dexmedetomidine combined with ropivacaine on sciatic and femoral nerve blockade in dogs.

OBJECTIVE: To evaluate motor and sensory blockade of combining dexmedetomidine with ropivacaine, administered perineurally or systemically, for femoral and sciatic nerve blocks in conscious dogs. STUDY DESIGN: Randomized, controlled, experimental study. ANIMALS: Seven healthy Beagle dogs, aged 3.3 ± 0.1 years and weighing 11.0 ± 2.4 kg. METHODS: Dogs were anesthetized with isoflurane on three separate occasions for unilateral femoral and sciatic nerve blocks and were administered the following treatments in random order: perineural ropivacaine 0.75% (0.1 mL kg-1) on each nerve and intramuscular (IM) saline (0.2 mL kg-1) (Gcon); perineural dexmedetomidine (1 µg mL-1) and ropivacaine 0.75% (0.1 mL kg-1) on each nerve and IM saline (0.2 mL kg-1) (GDPN); and perineural ropivacaine 0.75% (0.1 mL kg-1) on each nerve and IM dexmedetomidine (1 µg mL-1, 0.2 mL kg-1) (Gdim). Nerve blocks were guided by ultrasound and electrical stimulation and dogs were allowed to recover from general anesthesia. Sensory blockade was evaluated by response to clamp pressure on the skin innervated by the saphenous/ femoral, common fibular and tibial nerves. Motor blockade was evaluated by observing the ability to walk and proprioception. Sensory and motor blockade were evaluated until their full recovery. RESULTS: No significant differences in onset time to motor and sensory blockade were observed among treatments. Duration of motor blockade was not significantly different among treatments; however, duration of tibial sensory blockade was longer in the Gdpn than in the GDIM treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Although a longer duration of sensory blockade was observed with perineural dexmedetomidine, a significant increase compared with the control group was not established. Other concentrations should be investigated to verify if dexmedetomidine is a useful adjuvant to local anesthetics in peripheral nerve blocks in dogs.

Copaiba oil in experimental wound healing in horses / Óleo de Copaíba na cicatrização de feridas experimentais em cavalos

ABSTRACT: The aim of this study was to evaluate the effects of 10% copaiba oil in experimentally induced wounds in horses. Four wounds were made in the lumbar and metacarpal regions of eight adult horses. In the treatment group, the wounds received 10% copaiba oil and in the control group 0.9% sodium chloride, in the daily dressing for 21 days. The wounds were evaluated three, 7, 14, and 21 days postoperatively. No significant differences were observed between the groups. The mean lumbar wound contraction rates were 80.54% and 69.64%, for the control and treated groups, respectively. For the wounds in the metacarpal region, these averages were 44.15% and 52.48%, respectively. Under the experimental conditions of the present study, it is concluded that 10% copaiba oil has beneficial in wound healing in the equine species and suggest that copaiba oil can be used as a therapeutic possibility in equine wound therapy.

RESUMO: O objetivo deste estudo foi avaliar os efeitos do óleo de copaíba a 10% em feridas induzidas experimentalmente em equinos. Quatro feridas foram confeccionadas nas regiões lombares e metacarpianas de oito cavalos adultos. No grupo tratamento, as feridas receberam óleo de copaíba a 10% e no grupo controle, cloreto de sódio a 0,9% nos curativos diários durante 21 dias. As avaliações das feridas foram feitas aos 3, 7, 14, e 21 dias de pós-operatório. Não foram observadas diferenças significativas entre os grupos estudados. As médias das taxas de contração das feridas lombares foram 79,24% e 69,64%, para o grupo controle e tratado, respectivamente. Nas feridas do metacarpo, estas médias foram 44,78% e 52,05%, respectivamente. Nas condições experimentais deste estudo, conclui-se que o óleo de copaíba a 10% foi benéfico na cicatrização de feridas na espécie equina, sendo uma alternativa terapêutica para cura de feridas nesta espécie.

Age structure of owned dogs under compulsory culling in a visceral leishmaniasis endemic area.

The age structure of the dog population is essential for planning and evaluating control programs for zoonotic diseases. We analyzed data of an owned-dog census in order to characterize, for the first time, the structure of a dog population under compulsory culling in a visceral leishmaniasis endemic area (Panorama, São Paulo State, Brazil) that recorded a dog-culling rate of 28% in the year of the study. Data on 1,329 households and 1,671 owned dogs revealed an owned dog:human ratio of 1:7. The mean age of dogs was estimated at 1.73 years; the age pyramid indicated high birth and mortality rates at the first year of age with an estimated cumulative mortality of 78% at the third year of age and expected life span of 2.75 years. In spite of the high mortality, a growth projection simulation suggested that the population has potential to grow in a logarithmic scale over the years. The estimated parameters can be further applied in models to maximize the impact and minimize financial inputs of visceral leishmaniasis control measures.

Reduction in cytoplasmic lipid content in bovine embryos cultured in vitro with linoleic acid in semi-defined medium is correlated with increases in cryotolerance.

UNLABELLED: We examined whether culturing embryos with linoleic acid (LA) in semi-defined medium reduces lipid accumulation and improves cryosurvival after vitrification. Embryos were cultured with LA (100 µM) and a semi-defined medium was used during in vitro culture (IVC), in which the fetal calf serum was substituted by bovine serum albumin (BSA). There was a reduction (P < 0.05) in the embryonic development rate ( CONTROL: 25.8% versus LA: 18.5%), but the proposed system was effective in promoting the decrease (P = 0.0130) in the intracellular lipid content ( CONTROL: 27.3 ± 0.7 versus LA: 24.6 ± 0.7 arbitrary fluorescence units of embryos stained with the fluorescent dye Nile Red), consequently increasing (P = 0.0490) the embryo survival after 24h of culture post-warming ( CONTROL: 50.0% versus LA: 71.7%). The results question the criteria used to evaluate the efficiency of an in vitro production system specifically with relation to the maximum number of blastocysts produced and suggest that might be more appropriate to improve the desired characteristics of embryos generated in accordance with the specific purpose of in vitro embryo production, commercial or scientific. In conclusion, supplying LA to serum-free culture medium was found to adversely affect the rates of embryo development to the blastocyst stage, but significantly reduced embryo lipid accumulation and improved cryopreservation survival.

Continuous infusion of propofol in calves: bispectral index and hemodynamic effects.

OBJECTIVE: To assess the bispectral index (BIS) and the hemodynamic effects of propofol administered by continuous infusion at different rates in calves. STUDY DESIGN: Experimental crossover study. ANIMALS: Eight intact male Dutch calves, aged 6-12 months and weighing 84-124 kg. METHODS: The calves were anesthetized with propofol (5 mg kg(-1) ) intravenously (IV), and after endotracheal intubation, positioned in right lateral recumbency and allowed to breathe ambient air. Anesthesia was maintained by continuous infusion of propofol, administered IV with an infusion pump at 0.6 mg kg(-1)  minute(-1) (treatment G6) or 0.8 mg kg(-1)  minute(-1) IV (treatment G8), for 60 minutes. The eight animals were anesthetized twice, 1 week apart. The following hemodynamic variables and BIS were assessed before the induction of anesthesia (baseline) and 15, 30, 45, and 60 minutes after beginning the infusion of propofol: heart rate, systolic, diastolic and mean arterial pressures, cardiac output, mean pulmonary artery pressure, cardiac index, stroke index, pulmonary vascular resistance index, and systemic vascular resistance index, BIS, electromyography, and signal quality index. RESULTS: The continuous infusions of propofol at different rates did not alter BIS variables during the infusion time between dose rates, and no clinically significant hemodynamic changes were observed. CONCLUSIONS AND CLINICAL RELEVANCE: A continuous infusion of propofol at 0.6 or 0.8 mg kg(-1)  minute(-1) caused minimal hemodynamic changes without clinical relevance in calves. BIS could not be reliably used to discriminate the anesthetic depth during the two propofol infusion rates.

Age structure of owned dogs under compulsory culling in a visceral leishmaniasis endemic area / A estrutura etária de cães com donos numa área endêmica de leishmaniose visceral / Estructura etaria de la población canina domiciliada en un área endémica con leishmaniasis visceral canina

Abstract: The age structure of the dog population is essential for planning and evaluating control programs for zoonotic diseases. We analyzed data of an owned-dog census in order to characterize, for the first time, the structure of a dog population under compulsory culling in a visceral leishmaniasis endemic area (Panorama, São Paulo State, Brazil) that recorded a dog-culling rate of 28% in the year of the study. Data on 1,329 households and 1,671 owned dogs revealed an owned dog:human ratio of 1:7. The mean age of dogs was estimated at 1.73 years; the age pyramid indicated high birth and mortality rates at the first year of age with an estimated cumulative mortality of 78% at the third year of age and expected life span of 2.75 years. In spite of the high mortality, a growth projection simulation suggested that the population has potential to grow in a logarithmic scale over the years. The estimated parameters can be further applied in models to maximize the impact and minimize financial inputs of visceral leishmaniasis control measures.

Resumo: É importante conhecer a estrutura etária da população canina para melhor planejar e avaliar os programas de controle de zoonoses. Os autores analisaram os dados de um censo de cães com donos para caracterizar, pela primeira vez, a estrutura etária de uma população canina sujeita à eliminação compulsória numa área endêmica de leishmaniose visceral (Panorama, Estado de São Paulo, Brasil) que registrou uma taxa de eliminação canina de 28% no ano do estudo. Os dados para 1.329 domicílios e 1.671 cães com donos mostraram uma razão de cães para humanos de 1:7. A média de idade dos cães foi estimada em 1,73 anos; a pirâmide etária indicou altas taxas de natalidade e de mortalidade no primeiro ano de vida, com uma estimativa de mortalidade cumulativa de 78% aos três anos de idade, e uma expectativa de vida de 2,75 anos. Apesar da alta mortalidade, uma simulação de projeção de crescimento sugeriu que a população tem o potencial de crescer numa escala logarítmica ao longo dos anos. Os parâmetros estimados podem ser aplicados também a modelos para maximizar o impacto e minimizar os insumos financeiros de medidas de controle da leishmaniose visceral.

Resumen: El conocimiento de la estructura etaria de una población de perros es esencial para la planificación de programas de control de zoonosis. Se analizaron datos de un censo de población canina domiciliada, con el objetivo de caracterizar, por primera vez, la estructura de una población de perros domiciliados en un área donde la eutanasia de perros positivos en leishmaniasis visceral es obligatoria (Panorama, São Paulo, Brasil), y que registró un 28% de casos de eutanasia en el año en que el censo fue realizado. Los datos de 1.329 domicilios y 1.671 perros resultaron en una razón perro:hombre de 1:7. La edad media de los perros fue estimada en 1,73 años; la pirámide de edad indica altas tasas de nacimiento y mortalidad hasta 1 año de vida, con tasa de mortalidad acumulada de un 78% en el tercer año de vida, y expectativa de vida de 2,75 años. A pesar de la alta tasa de mortalidad, la simulación de crecimiento poblacional sugiere que esta población tiene potencial de crecimiento en escala logarítmica a lo largo de los años. Los parámetros estimados pueden ser utilizados en modelos para maximizar el impacto y minimizar los costes de las medidas de control de la enfermedad.

Genome-Wide Scan for Visceral Leishmaniasis in Mixed-Breed Dogs Identifies Candidate Genes Involved in T Helper Cells and Macrophage Signaling.

We conducted a genome-wide scan for visceral leishmaniasis in mixed-breed dogs from a highly endemic area in Brazil using 149,648 single nucleotide polymorphism (SNP) markers genotyped in 20 cases and 28 controls. Using a mixed model approach, we found two candidate loci on canine autosomes 1 and 2. The positional association on chromosome 2 mapped to a predicted DNAse sensitive site in CD14+ monocytes that serve as a cis-regulatory element for the expression of interleukin alpha receptors 2 (IL2RA) and 15 (IL15RA). Both interleukins were previously found to lead to protective T helper 1 cell (Th1) response against Leishmania spp. in humans and mice. The associated marker on chromosome 1 was located between two predicted transcription factor binding sites regulating the expression of the transducin-like enhancer of split 1 gene (TLE1), an important player in Notch signaling. This pathway is critical for macrophage activity and CD4+ T cell differentiation into Th1 and T helper 2. Together, these findings suggest that the human and mouse model for protective response against Leishmania spp., which involves Th1 and macrophage modulation by interleukins 2, 15, gamma interferon and Notch signaling, may also hold for the canine model.

Tissue apoptosis in mice infected with Leptospira interrogans serovar Icterohaemorrhagiae.

BACKGROUND: This investigation aimed to evaluate the occurrence of some apoptotic features induced by Leptospira interrogans serovar Icterohaemorrhagiae infection in young BALB/c mice during 2, 4, 7, 10, 14 and 21 days post-infection (dpi). METHODS: The animals were euthanized and lung, liver and kidneys were harvested to histopathology analysis and immunohistochemistry to caspase-3 antigen detection was performed. RESULTS: Chromatin condensation in kidney and liver tissues, but not in lung tissue, was observed. Caspase-3 reactive cells, mainly characterized as renal epithelial cells, were detected in the days 14 and 21 at high levels when compared to days 2, 4 and 7 (p = 0.025; p < 0.05). Lung sections revealed caspase-3 labeled alveolar cells in 10 and 14 days post-infection was higher than observed at 7 days (p = 0.0497; p < 0.05). Liver sections demonstrated reactive cells at a highest level at 14 and 21 days post-infection when comparison to 2, 4, 7 and 10 days (p = 0.0069; p < 0.05). CONCLUSIONS: Our results suggest that infection of L. interrogans induce in kidney, liver and lung an activation of apoptosis mediated by caspase-3 dependent pathway in later phases of infectious process.

First Molecular Characterization of Cryptosporidium spp. Infecting Buffalo Calves in Brazil.

With the aim of determining the occurrence of Cryptosporidium spp., 222 fecal samples were collected from Murrah buffalo calves aged up to 6 mo. Fecal DNA was genotyped with a nested polymerase chain reaction targeting the 18S rRNA gene and sequencing of the amplified fragment. Nested 18S PCR was positive for 48.2% of the samples. Sequence analysis showed that the most frequent species in these animals was Cryptosporidium ryanae, which was present in buffalo calves as young as 5 d. The zoonotic species Cryptosporidium parvum was detected in one animal. An uncommon Cryptosporidium 18S genotype was found in buffaloes.

Tissue apoptosis in mice infected with Leptospira interrogans serovar Icterohaemorrhagiae

Background: This investigation aimed to evaluate the occurrence of some apoptotic features induced by Leptospira interrogans serovar Icterohaemorrhagiae infection in young BALB/c mice during 2, 4, 7, 10, 14 and 21 days post-infection (dpi). Methods: The animals were euthanized and lung, liver and kidneys were harvested to histopathology analysis and immunohistochemistry to caspase-3 antigen detection was performed. Results: Chromatin condensation in kidney and liver tissues, but not in lung tissue, was observed. Caspase-3 reactive cells, mainly characterized as renal epithelial cells, were detected in the days 14 and 21 at high levels when compared to days 2,4 and 7 (p = 0.025; p <0.05). Lung sections revealed caspase-3 labeled alveolar cells in 10 and 14 days post-infection was higher than observed at 7 days (p = 0.0497; p < 0.05). Liver sections demonstrated reactive cells at a highest level at 14 and 21 days post-infection when comparison to 2,4, 7 and 10 days (p = 0.0069; p<0.05). Conclusions: Our results suggest that infection of L interrogans induce in kidney, liver and lung an activation of apoptosis mediated by caspase-3 dependent pathway in later phases of infectious process.

Tissue apoptosis in mice infected with Leptospira interrogans serovar Icterohaemorrhagiae

Background:This investigation aimed to evaluate the occurrence of some apoptotic features induced by Leptospira interrogans serovar Icterohaemorrhagiae infection in young BALB/c mice during 2, 4, 7, 10, 14 and 21 days post-infection (dpi).Methods:The animals were euthanized and lung, liver and kidneys were harvested to histopathology analysis and immunohistochemistry to caspase-3 antigen detection was performed.Results:Chromatin condensation in kidney and liver tissues, but not in lung tissue, was observed. Caspase-3 reactive cells, mainly characterized as renal epithelial cells, were detected in the days 14 and 21 at high levels when compared to days 2,4 and 7 (p = 0.025; p <0.05). Lung sections revealed caspase-3 labeled alveolar cells in 10 and 14 days post-infection was higher than observed at 7 days (p = 0.0497; p < 0.05). Liver sections demonstrated reactive cells at a highest level at 14 and 21 days post-infection when comparison to 2,4, 7 and 10 days (p = 0.0069; p<0.05).Conclusions:Our results suggest that infection of L interrogans induce in kidney, liver and lung an activation of apoptosis mediated by caspase-3 dependent pathway in later phases of infectious process.(AU)