Mathematical model calibrated to in vitro data predicts mechanisms of antiviral action of the influenza defective interfering particle "OP7".

Defective interfering particles (DIPs) are regarded as potent broad-spectrum antivirals. We developed a mathematical model that describes intracellular co-infection dynamics of influenza standard virus (STV) and "OP7", a new type of influenza DIP discovered recently. Based on experimental data from in vitro studies to calibrate the model and confirm its predictions, we deduce OP7's mechanisms of interference, which were yet unknown. Simulations suggest that the "superpromoter" on OP7 genomic viral RNA enhances its replication and results in a depletion of viral proteins. This reduces STV genomic RNA replication, which appears to constitute an antiviral effect. Further, a defective viral protein (M1-OP7) likely causes the deficiency of OP7's replication. It appears unable to bind to genomic viral RNAs to facilitate their nuclear export, a critical step in the viral life cycle. An improved understanding of OP7's antiviral mechanism is crucial toward application in humans as a prospective antiviral treatment strategy.

Influence of probiotic supplementation on parasitological parameters in lambs.

The control of parasitosis is based on the use of anthelmintics. However, its long-term and indiscriminate use can select populations of resistant nematodes. New alternatives such as probiotics are being studied to solve this problem. This study aimed to investigate the effects of an oral probiotic containing six different bacterial strains and the yeast Saccharomyces cerevisiae on the blood biochemistry, parasitological, and histological parameters of naturally infected lambs. Forty-two weaned Texel or Ile de France crossbred lambs aged 86.9 ± 8.0 days and weighing 27.4 ± 3.7 kg were randomly allocated into three groups (n = 14 lambs). The control group (CG) was fed a basal diet without probiotic supplementation. The treatment group 1 g (T1G) was fed a basal diet with commercial probiotic supplementation at a dose of 1 g/lamb/day. The treatment group 5 g (T5G) was fed a basal diet with commercial probiotic supplementation at a dose of 5 g/lamb/day. The experimental period was 84 days, where the groups undergo mild natural infection. Every two weeks the hematocrit, total protein, albumin, globulin, fibrinogen, plasma protein, fecal egg count (FEC), and fecal consistency score were evaluated. Twenty lambs were slaughtered for histological evaluation of the rumen and abomasal wall and for counting abomasal nematodes. The area, length, and number of eggs from the recovered Haemonchus contortus female uteri were measured. Data were analyzed using analysis of variance (ANOVA) and Tukey's test (p ≤ 0.05). The area and length of Haemonchus contortus females from T1G were smaller (p < 0.01) than those of CG and T5G. The number of eggs from the H. contortus female uterus was lower (p < 0.01) in T1G and T5G. Evaluating the incidence of diarrhea, the T1G and T5G groups had a higher prevalence with a 35% and 39% score of zero, respectively (p < 0.05), while the CG group had 22%. All other evaluated parameters showed no significant differences (p > 0.05) between the groups. The probiotic had a beneficial effect on the gastrointestinal health of the weaned lambs through a decrease of the area, length, and the number of eggs of female H. contortus and an improvement in fecal consistency.

Catching Speedy Gonzales: Driving forces for Protein Film Formation on Silicone Rubber Tubing During Pumping.

Interfacial adsorption is a major concern in the processing of biopharmaceutics as it not only leads to a loss of protein, but also to particle formation. Protein particle formation during peristaltic pumping is linked to interfacial adsorption to the tubing and subsequent tearing of the formed protein film. In the current study, driving forces and rate of the adsorption of a monoclonal antibody to the silicone rubber surface during pumping, as well as particle formation, were studied in different formulations. Particle concentration and size distribution were influenced by the formulation parameters; specifically high ionic strength led to more particles and the build-up of particles larger than 25 µm. Formulation pH and ionic strength had an effect on the total amount of adsorbed protein. Adsorbed protein amounts increased when the Debye length of the protein was decreased, leading to a higher packing density. Atomic force microscopy and streaming potential determination revealed that the irreversible protein film formation on the hydrophobic tubing surface occurs in less than a second. Electrostatic interactions are the dominating factor for the initial adsorption speed. In intimate contact to the silicone rubber surface, hydrophobic interactions govern the protein adsorption. PS20 quickly coats the tubing surface which leads to an increase in hydrophilicity and shielding of electrostatic interactions, thereby efficiently inhibiting protein adsorption. Overall, atomic force microscopy and streaming potential determination possess great potential for the characterization of adsorbed protein films and the adsorption kinetic evaluation in high-speed mode. Protein adsorption to silicone tubing is driven by a combination of electrostatic and hydrophobic interactions which is effectively shielded by PS20.

Effect of trimming of overgrown and deformed claws in goats on morphometric measurements.

Reduced welfare and productivity of dairy goats have often been associated with poor claw health, especially conditions such as claw overgrowth and deformations. It is known that periodic claw trimmings have prophylactic and therapeutic effects on these problems, and this study aimed to evaluate if the additional use of an angle grinder to finish trimming overgrown and deformed goat claws, after the usual trimming using hoof shears, could provide further changes in these claws. For this, twelve Saanen goats (57.29 ± 11.15 kg of body weight, 3.08 ± 1.78 years old) were selected by presence of severe claw overgrowth, and absence of claw alterations of other nature. Their claws were trimmed in two steps, first using hoof shears and then using an angle grinder. Morphometric, baropodometric, and conformational aspects of all claws were assessed before claw trimming and after each trimming step. To analyse the effects of the trimming steps in each claw, the Tukey's test was used on parametric data, with 5% probability, and descriptive statistics were used on non-parametric data. Although this is a small pilot study, results suggest that using an angle grinder after the use of hoof shears, could further reduce heel length and sole width of claws, as well as reduce the number of deformed claws. The incorporation of the second trimming tool, could also further increase the frequency with which the point of maximum pressure was found in the toes, rather then in the heels of the claws as seen in deformed claws.

Can orange essential oil reduce the severity of parasitic infection in sheep?

In this study, a three-step experiment was conducted to evaluate the effectiveness of orange essential oil (OEO) to reduce the severity of parasitic infection in lambs naturally infected with gastrointestinal parasites. In the first and second stages of the experiment, the lambs were distributed in groups (n = 10): without treatment (control), treated with levamisole (7.5 mg/kg), and treated either with 200, 300 or 400 mg/kg OEO in the first stage and with two doses of 300 or 350 mg/kg each of OEO with a six-hour interval in the second stage. In the third stage of the experiment, 20 lambs were distributed into control and treated groups (two doses of 350 mg/kg OEO) and slaughtered for determining the parasite count in the abomasum and small intestine. Evaluations were performed on D0, D3, D7, D10, and D14 by determining the egg count per gram of feces (EPG), and the percentage of EPG reduction was calculated in comparison to D0. Coproculture was performed on days D0 and D14 of the first and second stages of the study. In the first stage, the EPG increased by 20.90 and 100.99% and decreased by 5.54% on D14 in the groups treated with 200, 300, or 400 mg/kg OEO, respectively. At the second stage, the EPG of the OEO groups decreased by more than 96% on D3, but on D14 was decreased by 0.82% and 77.07% in the 2 × 300 and 2 × 350 mg/kg groups, respectively. Haemonchus sp. was the highest percentage of collected larvae in all coproculture tests, ranging from 90 to 100%. In the third stage, there was no difference (P > 0.05) in the mean number of parasites between the OEO groups and the control. Although the decrease in EPG of more than 96% on D3 did not persist in the other evaluations, and immature forms and adult parasites were collected at slaughter, the EPG reduction of 77.07% on D14 with the dose of 700 mg/kg (OEO2 × 350) suggests that OEO can help to reduce the severity of parasitic infection and, consequently, to diminish pastures contamination, when used together with other methods to control gastrointestinal parasites in sheep.

Mechanical Aspects of Angiogenesis.

Angiogenesis is of high clinical relevance as it plays a crucial role in physiological (e.g., tissue regeneration) and pathological processes (e.g., tumor growth). Besides chemical signals, such as VEGF, the relationship between cells and the extracellular matrix (ECM) can influence endothelial cell behavior during angiogenesis. Previously, in terms of the connection between angiogenesis and mechanical factors, researchers have focused on shear forces due to blood flow. However, it is becoming increasingly important to include the direct influence of the ECM on biological processes, such as angiogenesis. In this context, we focus on the stiffness of the surrounding ECM and the adhesion of cells to the ECM. Furthermore, we highlight the mechanical cues during the main stages of angiogenesis: cell migration, tip and stalk cells, and vessel stabilization. It becomes clear that the different stages of angiogenesis require various chemical and mechanical cues to be modulated by/modulate the stiffness of the ECM. Thus, changes of the ECM during tumor growth represent additional potential dysregulations of angiogenesis in addition to erroneous biochemical signals. This awareness could be the basis of therapeutic approaches to counteract specific processes in tumor angiogenesis.

Multiscale model of defective interfering particle replication for influenza A virus infection in animal cell culture.

Cell culture-derived defective interfering particles (DIPs) are considered for antiviral therapy due to their ability to inhibit influenza A virus (IAV) production. DIPs contain a large internal deletion in one of their eight viral RNAs (vRNAs) rendering them replication-incompetent. However, they can propagate alongside their homologous standard virus (STV) during infection in a competition for cellular and viral resources. So far, experimental and modeling studies for IAV have focused on either the intracellular or the cell population level when investigating the interaction of STVs and DIPs. To examine these levels simultaneously, we conducted a series of experiments using highly different multiplicities of infections for STVs and DIPs to characterize virus replication in Madin-Darby Canine Kidney suspension cells. At several time points post infection, we quantified virus titers, viable cell concentration, virus-induced apoptosis using imaging flow cytometry, and intracellular levels of vRNA and viral mRNA using real-time reverse transcription qPCR. Based on the obtained data, we developed a mathematical multiscale model of STV and DIP co-infection that describes dynamics closely for all scenarios with a single set of parameters. We show that applying high DIP concentrations can shut down STV propagation completely and prevent virus-induced apoptosis. Interestingly, the three observed viral mRNAs (full-length segment 1 and 5, defective interfering segment 1) accumulated to vastly different levels suggesting the interplay between an internal regulation mechanism and a growth advantage for shorter viral RNAs. Furthermore, model simulations predict that the concentration of DIPs should be at least 10000 times higher than that of STVs to prevent the spread of IAV. Ultimately, the model presented here supports a comprehensive understanding of the interactions between STVs and DIPs during co-infection providing an ideal platform for the prediction and optimization of vaccine manufacturing as well as DIP production for therapeutic use.

Semi-continuous Propagation of Influenza A Virus and Its Defective Interfering Particles: Analyzing the Dynamic Competition To Select Candidates for Antiviral Therapy.

Defective interfering particles (DIPs) of influenza A virus (IAV) are naturally occurring mutants that have an internal deletion in one of their eight viral RNA (vRNA) segments, rendering them propagation-incompetent. Upon coinfection with infectious standard virus (STV), DIPs interfere with STV replication through competitive inhibition. Thus, DIPs are proposed as potent antivirals for treatment of the influenza disease. To select corresponding candidates, we studied de novo generation of DIPs and propagation competition between different defective interfering (DI) vRNAs in an STV coinfection scenario in cell culture. A small-scale two-stage cultivation system that allows long-term semi-continuous propagation of IAV and its DIPs was used. Strong periodic oscillations in virus titers were observed due to the dynamic interaction of DIPs and STVs. Using next-generation sequencing, we detected a predominant formation and accumulation of DI vRNAs on the polymerase-encoding segments. Short DI vRNAs accumulated to higher fractions than longer ones, indicating a replication advantage, yet an optimum fragment length was observed. Some DI vRNAs showed breaking points in a specific part of their bundling signal (belonging to the packaging signal), suggesting its dispensability for DI vRNA propagation. Over a total cultivation time of 21 days, several individual DI vRNAs accumulated to high fractions, while others decreased. Using reverse genetics for IAV, purely clonal DIPs derived from highly replicating DI vRNAs were generated. We confirm that these DIPs exhibit a superior in vitro interfering efficacy compared to DIPs derived from lowly accumulated DI vRNAs and suggest promising candidates for efficacious antiviral treatment. IMPORTANCE Defective interfering particles (DIPs) emerge naturally during viral infection and typically show an internal deletion in the viral genome. Thus, DIPs are propagation-incompetent. Previous research suggests DIPs as potent antiviral compounds for many different virus families due to their ability to interfere with virus replication by competitive inhibition. For instance, the administration of influenza A virus (IAV) DIPs resulted in a rescue of mice from an otherwise lethal IAV dose. Moreover, no apparent toxic effects were observed when only DIPs were administered to mice and ferrets. IAV DIPs show antiviral activity against many different IAV strains, including pandemic and highly pathogenic avian strains, and even against nonhomologous viruses, such as SARS-CoV-2, by stimulation of innate immunity. Here, we used a cultivation/infection system, which exerted selection pressure toward accumulation of highly competitive IAV DIPs. These DIPs showed a superior interfering efficacy in vitro, and we suggest them for effective antiviral therapy.

Adverse reactions after orange essential oil administration to lambs.

The major compound in orange essential oil (OEO) is limonene, which has in vitro anthelmintic properties; however, a safe in vivo dose has not been defined for animals. Therefore, a pilot study was conducted to evaluate the effect of an OEO formulation for the control of gastrointestinal nematodes in sheep and to investigate adverse reactions in lambs after OEO administration. A total of 17 lambs received an oral OEO formulation at a concentration of 600 mg/mL, in doses of 200, 300, and 600 mg/kg. The most common clinical signs observed were head shaking (88.8%), backward head movement (51.1%), and ataxia (74.4%). Lambs treated with 600 mg/kg of OEO showed more severe combined clinical signs and longer duration of symptoms, presenting adverse reactions for up to 2 h after OEO administration. Testing of different doses and formulations with slower release of the active ingredient is recommended to minimize or eliminate these effects.

Cell-Based Strain Remodeling of a Nonfibrous Matrix as an Organizing Principle for Vasculogenesis.

Endothelial tube formation on a reconstituted basement membrane (Matrigel) is a well-established in vitro model for studying the processes of angiogenesis and vasculogenesis. However, to date, the organizing principles that underlie the morphogenesis of this network and that shape the initial process of cells' finding one another remain elusive. Here, we identify a mechanism that allows cells to form networks by mechanically reorganizing and stiffening their extracellular matrix, independent of chemical guidance cues. Interestingly, we find that this cellular self-organization strongly depends on the connectivity, plasticity, and topology of the surrounding matrix; cell contractility; and cell density. Cells rearrange the matrix and form bridges of matrix material that are stiffer than their surroundings, thus creating a durotactic track for the initiation of cell protrusions and cell-cell contacts. This contractility-based communication via strain stiffening and matrix rearrangement might be a general organizing principle during tissue development or regeneration.

Validation of device for detection of metallic foreign bodies in cattle / Validação de aparelho para detecção de corpos estranhos metálicos em bovinos

ABSTRACT: The ingestion of foreign bodies, mainly metallic (MFB- metallic foreign body), by cattle is frequent and can lead to death. For diagnostic purposes, reticular pain tests are routinely used, and ferroscopy is still unusual, even as a diagnostic aid. The objective of this study was to validate the application of the GMS 120 Professional BOSCH® metal detector (MD) in the detection of MFB in the bovine species and describe its use in field cases. Fifty MFBs of varying shape, size, and weight were evaluated with an MD, initially on a flat and inert surface, and then in a permanent rumen fistulated cow. Retrospectively, a database from 2000 to 2017 with 122015 cattle was accessed, of which 31865 were examined after the introduction of MD usage in 2013. Fifteen cows positive for reticular pain tests were prospectively evaluated and eight cows were diagnosed with MFB through MD usage. The mean distance for MFB best detection on the inert surface was 4.6 cm. In the fistulated cow, it was not possible to detect any MFBs, regardless of the size or weight of the material. The MFB detection capacity increased with MD use, which can be considered a diagnostic aid in specific situations. Depending on the body condition of the bovine, false negatives may occur with the use of GMS 120 Professional Bosch® metal detector.

RESUMO: A ingestão de corpos estranhos, principalmente metálicos (CEM), pelos bovinos é frequente e pode levar à sua morte. Para fins diagnósticos, as provas de dor reticular são usados de forma rotineira, sendo ainda pouco usual a ferroscopia, mesmo como auxílio diagnóstico. Neste trabalho procurou-se validar a aplicação do detector de metais (DM), marca GMS 120 Professional BOSCH® no reconhecimento de CEM na espécie bovina, além de descrever seu uso em casos a campo. CEM (n=50) de forma, tamanho e peso variados foram selecionados e avaliados com o DM, inicialmente sobre uma superfície plana e inerte e depois in vivo em uma vaca com fístula ruminal. Retrospectivamente, acessou-se um banco de dados dos anos 2000 a 2017 com 122015 bovinos, com 31865 bovinos atendidos após a introdução do DM no ano de 2013. Prospectivamente, avaliaram-se 15 vacas positivas para o teste de dor reticular, oito vacas foram diagnosticadas com CEM através do DM. A distância média para a melhor detecção dos CEM na superfície inerte foi de 4,6 cm. Em vaca fistulada não foi possível detectar nenhum CEM, independentemente do tamanho e peso do material. A campo, após a introdução do uso do DM aumentou a capacidade de detecção dos CEM. O DM pode ser considerado um auxílio diagnóstico em situações específicas. Dependendo da condição corporal do bovino, falsos negativos podem ocorrer com o uso do aparelho GMS 120 Professional Bosch®.

Fiber stiffness, pore size and adhesion control migratory phenotype of MDA-MB-231 cells in collagen gels.

Cancer cell migration is influenced by cellular phenotype and behavior as well as by the mechanical and chemical properties of the environment. Furthermore, many cancer cells show plasticity of their phenotype and adapt it to the properties of the environment. Here, we study the influence of fiber stiffness, confinement, and adhesion properties on cancer cell migration in porous collagen gels. Collagen gels with soft fibers abrogate migration and promote a round, non-invasive phenotype. Stiffer collagen fibers are inherently more adhesive and lead to the existence of an adhesive phenotype and in general confined migration due to adhesion. Addition of TGF-ß lowers adhesion, eliminates the adhesive phenotype and increases the amount of highly motile amoeboid phenotypes. Highest migration speeds and longest displacements are achieved in stiff collagen fibers in pores of about cell size by amoeboid phenotypes. This elucidates the influence of the mechanical properties of collagen gels on phenotype and subsequently migration and shows that stiff fibers, cell sized pores, and low adhesion, are optimal conditions for an amoeboid phenotype and efficient migration.

Aspects of lameness in pasture based dairy systems.

Pasture-based dairy systems are implemented all over the world. Access to pasture is perceived to be advantageous for animal welfare in western societies. However, the benefits of grazing on lameness are not uniformly verifiable. This is related to the challenges that grazing cows face which are different from zero-grazing systems to some extent, but may nevertheless be deleterious. The distribution of lesion types comparing housed and pastured cattle differs between studies. This may be caused by differences in how strongly certain risk factors apply in these studies. Major risk factors for lameness in grazing cattle are related to the risk of trauma, for example from long walking distances and lack of track maintenance, and cow factors such as the adaptability of certain breeds to the grazing lifestyle. The consequences of lameness are similar to zero-grazing cattle and negatively affect animal welfare and productivity.

Multiscale modeling of influenza A virus replication in cell cultures predicts infection dynamics for highly different infection conditions.

Influenza A viruses (IAV) are commonly used to infect animal cell cultures for research purposes and vaccine production. Their replication is influenced strongly by the multiplicity of infection (MOI), which ranges over several orders of magnitude depending on the respective application. So far, mathematical models of IAV replication have paid little attention to the impact of the MOI on infection dynamics and virus yields. To address this issue, we extended an existing model of IAV replication in adherent MDCK cells with kinetics that explicitly consider the time point of cell infection. This modification does not only enable the fitting of high MOI measurements, but also the successful prediction of viral release dynamics of low MOI experiments using the same set of parameters. Furthermore, this model allows the investigation of defective interfering particle (DIP) propagation in different MOI regimes. The key difference between high and low MOI conditions is the percentage of infectious virions among the total virus particle release. Simulation studies show that DIP interference at a high MOI is determined exclusively by the DIP content of the seed virus while, in low MOI conditions, it is predominantly controlled by the de novo generation of DIPs. Overall, the extended model provides an ideal framework for the prediction and optimization of cell culture-derived IAV manufacturing and the production of DIPs for therapeutic use.

Is the Famacha© system always the best criterion for targeted selective treatment for the control of haemonchosis in growing lambs?

Targeted selective treatment (TST) aims to aid in the control of gastrointestinal nematodes in small ruminants, identifying animals that require treatment with the purpose of preserving the Refugia population and delaying the buildup of anthelmintic (AH) resistance. The objective of this study was to evaluate the effectiveness of both productive and clinical indicators in the selective treatment of gastrointestinal parasites in growing lambs. Two experiments were carried out between 2015 and 2016. Experiment 1: lambs (n = 70) exclusively raised on pasture were evaluated from the ages of 60 days to 180 days old. Experiment 2: lambs (n = 48) raised on pasture and fed concentrated commercial supplementation were evaluated from the ages of 60 days to 150 days old. Parasitological (eggs per gram of feces - EPG), productive (average daily weight gain - DWG), and clinical (hematocrit - Ht and FAMACHA© system - F) parameters were measured every 14 days. The lambs were divided into 4 experimental groups with different criteria for AH treatment: the control group (CG), was treated with AH every 30 days; the FAMACHA© group (FG), in which lambs classified as F3, F4, and F5 were treated with AH; Daily weight gain group (DWGG), in which lambs with average DWG ≤ the average DWG of the CG minus one standard deviation were treated with AH; FAMACHA© + daily weight gain group (FDWGG), in which lambs classified as F3, F4 and F5 and/or lambs with average DWG ≤ the average DWG of the CG minus one standard deviation were treated with AH. In experiment 1, no significant differences in the general means of DWG and Ht (p > 0.05) were observed between experimental groups, although the lowest mean EPG was observed in the CG (p < 0.05). In experiment 2, the lowest mean EPG (p < 0.05) was also observed in the CG (1044.5 EPG), and the highest mean (p < 0.05) in the FG (4845.5 EPG). There were differences in the mean DWG of the CG (198.4 g) and FDWGG (200.0 g), which were both higher (p < 0.05) than that of the FG (90.5 g), and similar (p > 0.05) to the DWGG (151.8 g). In both experiments, considering the total mean number of AH treatments, FG had the lowest number of lambs treated with AH (p < 0.05), with the DWG and FDWGG being similar to each other (p > 0.05). Even when Haemonchus is the major parasite, it is not recommended to use the FAMACHA© system as an exclusive criterion for TST in growing lambs. The DWG productive criterion can be used effectively in the TST of growing lambs.

Zn2+-triggered self-assembly of Gonadorelin [6-D-Phe] to produce nanostructures and fibrils.

A synthetic derivative, GnRH [6-D-Phe], stable against enzymatic degradation, self-assembles and forms nanostructures and fibrils upon a pH shift in the presence of different concentrations of Zn2+ in vitro. Attenuated Total Reflection Fourier Transform Infrared spectroscopy (ATR-FTIR) revealed the existence of higher order assembly of Zn2+: GnRH [6-D-Phe]. Nuclear Magnetic Resonance spectroscopy (NMR) indicated a weak interaction between Zn2+ and GnRH [6-D-Phe]. Atomic Force Microscopy (AFM) showed the existence of GnRH [6-D-Phe] oligomers and fibrils. Molecular Dynamic (MD) simulation of the 10:1 Zn2+: GnRH [6-D-Phe] explored the interaction and dimerization processes. In contrast to already existing short peptide fibrils, GnRH [6-D-Phe] nanostructures and fibrils form in a Tris-buffered pH environment in a controlled manner through a temperature reduction and a pH shift. The lyophilized Zn2+: GnRH [6-D-Phe] assembly was tested as a platform for the sustained delivery of GnRH [6-D-Phe] and incorporated into two different oil vehicle matrices. The in vitro release was slow and continuous over 14 days and not influenced by the oil matrix.

Sensitivity and specificity of the FAMACHA© system in growing lambs.

The FAMACHA© system is used for targeted selective treatment (TST) of small ruminants for the control of haemonchosis. The aim of this study was to evaluate the sensitivity and specificity of this system in growing lambs. Between 2015 and 2016, lambs aged 60-210 days on two sheep farms were evaluated at 15-day intervals using the FAMACHA© system (F1-F5), with analysis of hematocrit (Ht), counting of eggs per gram of feces, and larval culture. The sensitivity and specificity of the system were calculated according to two criteria: criterion 1, lambs classified as F4 or F5 were considered anemic (positive test) and those classified as F1, F2, or F3 were considered not anemic (negative test); and criterion 2, lambs classified as F3, F4, or F5 were considered anemic (positive test) and those classified as F1 and F2 were considered not anemic (negative test). Three gold standard Ht cutoff values were used to diagnose anemia, i.e., ≤22%, ≤18%, and ≤15%. In total, 1591 assessments were analyzed. The highest percentage of larvae in the fecal cultures was for Haemonchus spp., with an average of 78.5%. The sensitivity values found when F3 lambs were considered anemic were 13.9%, 30.8%, and 66.7%, respectively, for Ht cutoff values of ≤22%, ≤18%, and ≤15%. When F3 lambs were excluded, the maximum sensitivity was 14.9% and the specificity was 100% for all degrees of anemia using criterion 1. The FAMACHA© system had low sensitivity in growing lambs and should not be used alone for control of haemonchosis in young animals.

Persistent inhibition of pore-based cell migration by sub-toxic doses of miuraenamide, an actin filament stabilizer.

Opposed to tubulin-binding agents, actin-binding small molecules have not yet become part of clinical tumor treatment, most likely due to the fear of general cytotoxicity. Addressing this problem, we investigated the long-term efficacy of sub-toxic doses of miuraenamide, an actin filament stabilizing natural compound, on tumor cell (SKOV3) migration. No cytotoxic effects or persistent morphological changes occurred at a concentration of miuraenamide of 20 nM. After 72 h treatment with this concentration, nuclear stiffness was increased, causing reduced migration through pores in a Boyden chamber, while cell migration and chemotaxis per se were unaltered. A concomitant time-resolved proteomic approach showed down regulation of a protein cluster after 56 h treatment. This cluster correlated best with the Wnt signaling pathway. A further analysis of the actin associated MRTF/SRF signaling showed a surprising reduction of SRF-regulated proteins. In contrast to acute effects of actin-binding compounds on actin at high concentrations, long-term low-dose treatment elicits much more subtle but still functionally relevant changes beyond simple destruction of the cytoskeleton. These range from biophysical parameters to regulation of protein expression, and may help to better understand the complex biology of actin, as well as to initiate alternative regimes for the testing of actin-targeting drugs.

Melanocitoma dérmico fibroso em bovino: relato de caso / Fibrous skin melanocitome in cattle: a case report / Melanocitoma dérmico fibroso en bovino: relato de caso

Melanomas e melanocitomas são neoplasias de melanoblastos e melanócitos. Neoplasias melanocíticas raramente são observadas em bovinos sendo frequentemente confundidas com outros aumentos de volume ou neoplasias, apresentando comportamento predominantemente benigno. É relatado um caso de melanocitoma em uma novilha da raça Jersey de oito meses de idade, descrevendo-se seu aspecto macro e microscópico. A neoplasia foi integralmente retirada por meio cirúrgico sem complicações ou recidivas até o momento. Ressalta-se a importância para este distúrbio, principalmente para o seu diagnóstico diferencial e a resolução relativamente descomplicada para o médico veterinário.(AU)

Melanoma and meloanocitome are melanoblast and melanocyte tumors. Melanocytic neoplasms are rarely observed in cattle and can be confused with other volume increases or neoplasms. Bovine melanoma is predominantly benign. One case of melanocitome in an 8-month old Jersey heifer is reported, describing their macro- and microscopic appearance. The tumor was completely removed by surgical means without complications. The importance of this disorder must be emphasized, especially for the differential diagnosis and the relatively uncomplicated resolution to the veterinarian.(AU)

Melanomas y melanocitomas son neoplasias de melanoblastos y melanocitos. Neoplasias melanocíticas son raramente observadas en bovino, a menudo se confunde con otros aumentos de volumen o neoplasias, presentando comportamiento predominantemente benigno. Es relatado un caso de malenocitoma en una novilla de la raza Jersey con ocho meses de edad, describiéndose su aspecto macro y microscópico. La neoplasia fue extirpada completamente por medio quirúrgico sin complicaciones o recidivas hasta el momento. Se resalta la importancia para este disturbio, especialmente para su diagnóstico diferencial y la resolución relativamente poco complicada para el médico veterinario.(AU)

Prion protein gene polymorphisms and accumulation of pathogenic prion protein (PrPSc) in a herd with previously confirmed scrapie cases / Polimorfismos do gene da proteína priônica celular (PRNP) e distribuição da proteína priônica alterada (PrPSc) em rebanho com surto anterior de scrapie

Scrapie in sheep is associated with at least three polymorphisms in the prion protein gene (PRNP) on codons 136, 154, and 171. Countries where scrapie is endemic have been using breeding programs based on selection for the most resistant alleles. There are some PRNP genotyping data on sheep in Brazil, and scrapie has sporadically been observed since 1978. Paraná is the Brazilian state where most of the cases of scrapie have been diagnosed. A flock that had three clinical scrapie cases in 2003 and 2004 was genotyped (128 sheep: 53 pure Hampshire Down and 75 crossbred) and slaughtered (111 sheep: 47 pure Hampshire Down and 64 crossbred) in 2006. Samples of lymphoid and central nervous tissues were examined by immunohistochemistry (IHC) for altered prion protein (PrPSc). Six genotypes were detected in the 128 genotyped animals: ARR/ARQ was the most frequent (45.3%), followed by ARQ/ARQ (28.1%), ARR/ARR (14.1%), and ARQ/VRQ (8.6%). ARR/VRQ and ARQ/AHQ showed less than 2.5% genotype frequency. IHC identified 16 positive sheep. Palatine tonsil tissue had the highest percentage of reactive samples: 81.25% of the total positive samples. Of these 16 positive animals, nine (56.25%) had genotype ARR/ARQ, five (31.25%) had genotype ARQ/ARQ, and the remaining two (12.5%) had genotype ARQ/VRQ. All the positive animals were clinically healthy, and therefore represented 14.14% of pre-clinical cases of scrapie in this flock.

Scrapie nos ovinos está associada a pelo menos três polimorfismos do gene da proteína priônica celular (PRNP) nos códons 136, 154 e 171. Países onde o scrapie é endêmico têm utilizado programas de melhoramento, com a seleção para os alelos mais resistentes. Há alguns dados disponíveis de genotipagem do PRNP em ovinos no Brasil, e o scrapie tem sido observado esporadicamente desde 1978. O Paraná é o Estado brasileiro onde a maioria dos casos de scrapie foi diagnosticada. Um rebanho, que teve três casos clínicos de scrapie em 2003 e 2004, foi genotipado (128 ovinos - 53 Hampshire Down e 75 mestiços) e abatido (111 ovinos - 47 Hampshire Down e 64 mestiços) em 2006. Amostras de tecido linfóide e sistema nervoso central foram examinadas por imunohistoquímica (IHQ) para presença de proteína priônica alterada (PrPSc). Seis genótipos foram encontrados nos 128 animais genotipados: ARR/ARQ foi o mais frequente (45,3%), seguido por ARQ/ARQ (28,1%), ARR/ARR (14,1%) e ARQ/VRQ (8,6%). ARR/VRQ e ARQ/AHQ apresentaram menos de 2,5% de freqüência do genótipo. Na IHC, 16 animais com exame positivo para a presença da proteína priônica celular alterada (PrPSc) foram detectados. As tonsilas foram o tecido com a mais alta porcentagem de amostras reativas: 81,25% do total das amostras positivas. Considerando os 16 animais positivos, nove (56,25%) tinham o genótipo ARR/ARQ, seguido pelo genótipo ARQ/ARQ com 31,25% (n = 5) e ARQ/VRQ com 12,5% (n = 2). Todos os animais positivos estavam clinicamente saudáveis, representando, portanto, 14,14% de casos pré-clínicos de scrapie neste rebanho.