Robert Domingues

Novel thalidomide analogues from diamines inhibit pro-inflammatory cytokine production and CD80 expression while enhancing IL-10.

Thalidomide is used to treat a variety of diseases including erythema nodosum leprosum, an inflammatory complication of leprosy. However, this drug has severe teratogenic activity and novel thalidomide analogues might be used to treat diseases without this severe side effect. A series of diamine compounds containing two hydrolyzed phthalimide units were chosen as analogues of thalidomide and evaluated regarding their capacity to regulate the production of molecules involved in inflammatory responses. TNF-α, IL-12 and IL-10 production, and the expression of CD80 and CD86 were investigated in LPS plus IFN-γ-stimulated J774A.1 cells by ELISA and flow cytometry, respectively. The expression of TNF-α and IL-10 mRNA was analyzed by real time RT-PCR. TNF-α, IL-6, IFN-γ, CXCL9 and CXCL10 production by human peripheral blood mononuclear cells (PBMC) were evaluated by flow cytometry. Compounds 3, 6 and 9 greatly inhibited TNF-α and IL-12 production while enhancing IL-10. In addition, CD80 expression was inhibited, but not CD86. The compounds inhibited TNF-α production by PBMC more than thalidomide and also had an inhibitory effect on the production of IL-6, IFN-γ, CXCL9 and CXCL10. Levels of mRNA for TNF-α were reduced after treatment with the compounds, suggesting post- transcriptional effects. The compounds had no effect on cell viability. Our results indicate that the novel diamine compounds 3, 6 and 9 inhibit critical pro-inflammatory cytokines and stimulate IL-10, which make them attractive candidate drugs for the treatment of certain inflammatory conditions and cancer.

Microarray analysis of tick-infested skin in resistant and susceptible cattle confirms the role of inflammatory pathways in immune activation and larval rejection

Tick bites promote activation of an inflammatory process that is influenced by bovine genetic composition and its history of previous exposure. Taurine and indicine breeds are known to differ on its immune response development against Rhipicephalus microplus. Nevertheless, further investigation about the complex molecular pathways involved in the development of immune response to tick infestation in cattle presenting the same genetic background is mandatory. The aim of this work was to access the early immune response triggered by R. microplus larvae attachment in previously selected resistant and susceptible animals in a bovine F2 population derived from Gyr (Bos indicus)×Holstein (Bos taurus) crosses. Microarray data analysis of RNA samples from tick infested skin was used to evaluate the gene expression at 0, 24 and 48h after R. microplus larvae attachment. Our experimental design allowed us to deeply explore the immune response related to R. microplus infestation avoiding the innate differences between these breeds. The differentially expressed genes found reveal networks and pathways that suggest a key role of lipid metabolism in inflammation control and impairment of tick infestation in resistant animals. Acute phase response also seems to be impaired in susceptible animals. These results provide new insights about early immune response against ticks and raise the possibility of using immunomodulation processes to improve and develop novel tools for tick control.

Uso de PCR e sequenciamento do rDNA 16S para identificação de bactérias do gênero Staphylococcus isoladas de mastite bovina

The objective of this study was to identify the species of 100 isolates of Staphylococcus from mastitis in dairy cows from herds located in the state of Minas Gerais, Brazil. PCR reactions were carried out using specific primers described previously for S. aureus (femA gene), S. intermedius (16S rDNA) and S. hyicus (16S-23S rDNA spacer region). In addition, products of amplification of variable regions of the 16S rDNA gene of the strains were sequenced. According to the results of the PCR, 83 strains were identified as S. aureus, 13 as S. intermedius, two as S. hyicus and two isolates were not identified. The sequencing of 16S rDNA was applied to 23 strains identified by PCR amplifications: six S. aureus and the strains identified as S. intermedius (n=13), S. hyicus (n=2) or not identified (n=2). The sequencing of 16S rDNA confirmed the six strains as S. aureus. The others 17 strains were identified as S. chromogenes (13 isolates) and S. hyicus (four isolates). Each sample was related to a specie according to the smallest E-value and highest similarity (> 99%). The identification of S. hyicus and S. chromogenes was accomplished only by 16S rDNA sequencing.

Effects of aqueous extract of Echinodorus grandiflorus on the immune response in ovalbumin-induced pulmonary allergy

BACKGROUND Asthma is a disease characterized by intermittent obstruction of the airways and chronic inflammation that affects approximately 300 million people worldwide. The immune response in asthma is predominantly T(H)2, with high levels of total and allergen-specific IgE and bronchial eosinophilia. Asthma treatment is aimed at controlling the disease, and the drugs used currently have systemic adverse effects and generally are not effective in difficult-to-control cases. OBJECTIVE To investigate the effect of aqueous extract of Echinodorus grandiflorus, a plant used in folk medicine for its diuretic and anti-inflammatory properties, in a model of pulmonary allergy. METHODS BALB/c mice were intraperitoneally sensitized and nasally challenged with ovalbumin. Aqueous extract and dexamethasone treatments (0.1 mL/d per mouse) were initiated on day 32 and concluded on day 40. Eight hours after the last challenge evaluations, of serum, bronchoalveolar lavage, and lung tissue were performed. RESULTS Oral treatment with the extract markedly reduced the number of total cells and eosinophils in bronchoalveolar lavage. The eosinophil peroxidase activity in lung tissue, the levels of ovalbumin-specific IgE in serum, the levels of CCL11, and the gene expression of interleukin 4 and interleukin 13 in lung tissue were also lower after treatment. CONCLUSIONS These results suggest that the aqueous extract of E grandiflorus is able to modulate allergic pulmonary inflammation and may be useful as a potential therapeutic agent for asthma.

The use of infrared images to detect ticks in cattle and proposal of an algorithm for quantifying the infestation

This paper presents a study on the use of low resolution infrared images to detect ticks in cattle. Emphasis is given to the main factors that influence the quality of the captured images, as well as to the actions that can increase the amount of information conveyed by these images. In addition, a new automatic method for analyzing the images and counting the ticks is introduced. The proposed algorithm relies only on color transformations and simple mathematical morphology operations, thus being easy to implement and computationally light. Tests were carried out using a large database containing images of the neck and hind end of the animals. It was observed that the proposed algorithm is very effective in detecting ticks visible in the images, even if the contrast with the background is not high. On the other hand, due to both intrinsic and extrinsic factors, the thermographic images used in this study did not always succeed in creating enough contrast between ticks and cattles hair coat. Although these problems can be mitigated by following some directives, currently only rough estimates for tick counts can be achieved using infrared images with low spatial resolution.