Haplotypes of the bovine IgG2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle

Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations.

Effects of Green Tea Use on Wound Healing

Green tea, a product from Camellia sinensis, consists of over 200 componentes. The most known are the catechins, ou polyphenolic compounds, or flavonoids, but it contains also polysacharide conjugates, amino acids, caffeine and vitamins. Studies have suggested that the regular consumption of green tea reduces the risk of cancer, protecting agains initial events and progression of the disease, may act as antioxidant, has bactericidal properties, and that green tea consumption may be an adjuvant in the treatment of diabetes mellitus, hypertension and hypercholesterolemia. Our experimental study was carried out with male Wistar rats, separated in two groups, experimental and control. The animals in control group were given water ad libitum, and the animals in the experimental group received green tea instead of water. After 2 weeks of experimental period, all the animals, suffered surgical wounds on the dorsum. The animals were sacrificed on I, 3 and 7 days after surgery. Skin samples were used for light microscopy evaluation. Our results allowed us to observe that the experimental group (green tea drinking) presented accelerated epithelial neformation on day 3 after surgery, when epithelial neoformation is in the initial phases. The surgical areas presented 48.20% X 27.32% epithelial neoformation for green tea group and their controls respectivelly at this time. The results of the present study, along with other information about green tea in the literature, strongly suggests that regular use of green tea may be beneficial in surgery situations, when fast epithelial neoformation is desirable.