Short report: Genetic variation of Echinococcus canadensis (G7) in Mexico

We evaluated the genetic variation of Echinococcus G7 strain in larval and adult stages using a fragment of the mitochondrial cox1 gen. Viscera of pigs, bovines, and sheep and fecal samples of dogs were inspected for cystic and canine echinococcosis, respectively; only pigs had hydatid cysts. Bayesian inferences grouped the sequences in an E. canadensis G7 cluster, suggesting that, in Mexico, this strain might be mainly present. Additionally, the population genetic and network analysis showed that E. canadensis in Mexico is very diverse and has probably been introduced several times from different sources. Finally, a scarce genetic differentiation between G6 (camel strain) and G7 (pig strain) populations was identified.

Fluorescence and inmunohistological detection of estrogen receptors in dog testis and epidydimis after oral coumestrol administration

INTRODUCTION

Estrogens are well recognized as important hormones in male reproduction and act as ligands to alpha and beta estrogen receptors. Both estrogen receptors could interact with estrogen-mimicking compounds such as the fluorescent phytoestrogen coumestrol, which acts both in an agonist or antagonist fashion.

OBJECTIVE

To investigate the presence of Coumestrol-Estrogen Receptor complexes by fluorescence in testis and epididymis, its effect in the ER expression by immunostain in the same tissues and the effect of this binding in the testis histological characteristics.

DESIGN

Adult healthy and sexually active dogs were assigned to either the experimental or control group .Coumestrol impregnated dog biscuits were given to each animal from the experimental group once a week for a 4 week period. The control group received a biscuit with no Coumestrol, also once a week and for the same period. Testis morphology, ER immunodetection, and coumestrol-receptor binding were evaluated.

SETTING

The experiment was done in the facilities of the Mexico City canine shelter. Animals were caged individually with food and water ad libitum and having at least two daily hours for exercise.

RESULTS

Morphological alterations in testis after oral administration of coumestrol were detected. The main alterations include decreased germinal epithelium in tubule, and the loss of a continuous proliferation and differentiation gamete layer. Fluorescence signals in testis interstitial Leydig cells and epididymus indicating ER-coumestrol complexes were detected at the same points to those Immunohystochemically detected ER.

CONCLUSIONS

Coumestrol administration induces testis alterations and coumestrol-ER complexes can be co-localized by binding-enhanced fluorescence and immunoprecipitation.