Intra-articular treatment with corticosteroids increases apoptosis in human rotator cuff tears.

PURPOSE: The aim of this study is to evaluate in vivo the level of apoptosis in human rotator cuff tears and the relationship it might have with tendon degeneration. METHODS: Rotator cuff biopsies from 19 male and female patients, ages between 38 and 68 years, with and without previous corticosteroid infiltrations were collected via arthroscopy. Biopsies from seven patients with healthy rotator cuffs were used as a control group. An in situ terminal deoxynucleotidyl transferase dUTP nick end labeling assay was performed to detect the level of apoptosis, which was expressed as a percentage of apoptotic cells (PAC). RESULTS: PAC in patients with corticosteroid infiltrations was 76.97 ± 16.99 in all tendon rupture zones, in non-infiltrated patients was 35.89 ± 22.96, whereas in control patients was 14.48 ± 8.15. Likewise, the tendency of PAC reveals that apoptosis in control and non-infiltrated groups was different and dispersed in all tear zones; while in corticosteroid treated patients, the tendency was similar in all rupture sites. CONCLUSIONS: This investigation leads us to conclude that the administration of corticosteroid is associated with a higher amount of apoptosis at the insertion site of the rotator cuff (rupture edge).

Xenopus laevis and Emerging Amphibian Pathogens in Chile.

Amphibians face an extinction crisis with no precedence. Two emerging infectious diseases, ranaviral disease caused by viruses within the genus Ranavirus and chytridiomycosis due to Batrachochytrium dendrobatidis (Bd), have been linked with amphibian mass mortalities and population declines in many regions of the globe. The African clawed frog (Xenopus laevis) has been indicated as a vector for the spread of these pathogens. Since the 1970s, this species has been invasive in central Chile. We collected X. laevis and dead native amphibians in Chile between 2011 and 2013. We conducted post-mortem examinations and molecular tests for Ranavirus and Bd. Eight of 187 individuals (4.3 %) tested positive for Ranavirus: seven X. laevis and a giant Chilean frog (Calyptocephallela gayi). All positive cases were from the original area of X. laevis invasion. Bd was found to be more prevalent (14.4 %) and widespread than Ranavirus, and all X. laevis Bd-positive animals presented low to moderate levels of infection. Sequencing of a partial Ranavirus gene revealed 100 % sequence identity with Frog Virus 3. This is the first report of Ranavirus in Chile, and these preliminary results are consistent with a role for X. laevis as an infection reservoir for both Ranavirus and Bd.

Proteomics analysis of Echinococcus granulosus protoscolex stage.

Echinococcus granulosus protoscolex proteins were separated using two-dimensional electrophoresis and then identified using mass spectrometry; we identified 61 proteins, 28 which are newly described of which 4 could be involved in hydatid cyst fertility molecular mechanisms.

Bovine IgG subclasses and fertility of Echinococcus granulosus hydatid cysts.

Hydatidosis is an important zoonotic disease of worldwide distribution, causing important health problems to humans and major economical losses in infected livestock. Echinococcus granulosus, the etiological agent of hydatid disease, induces a humoral immune response in the intermediate host (human and herbivorous) against hydatid cyst antigens. Specifically, IgGs are found in the laminar and germinal layers and inside the lumen of fertile and infertile hydatid cysts. In the germinal layer of infertile cysts IgGs are found in an order of magnitude greater than in the germinal layer of fertile cysts; a fraction of those IgGs are associated with high affinity to germinal layer proteins, suggesting their binding to specific parasite antigens. We have previously shown that those immunoglobulins, bound with high affinity to the germinal layer of hydatid cysts, induce apoptosis leading to cyst infertility. In the present work the presence of IgG1 and IgG2 subclasses in the germinal layer of both fertile and infertile hydatid cysts is reported. IgG1 is the most relevant immunoglobulin subclass present in the germinal layer of infertile cysts and bound with high affinity to that parasite structure. Contrarily, though the IgG2 subclass was also found in the germinal and adventitial layers, those immunoglobulins show low affinity to parasite antigens. We propose that the binding of an IgG1 subclass to parasite antigens present in the germinal layer is involved in the mechanism of cyst infertility.

Bovine (Bos taurus) humoral immune response against Echinococcus granulosus and hydatid cyst infertility.

Echinococcus granulosus, the agent of hydatid disease, presents an indirect life cycle, with canines (mainly dogs) as definitive hosts, and herbivores and human as intermediary ones. In intermediary hosts fertile and infertile cysts develop, but only the first ones develop protoscoleces, the parasite form infective to definitive hosts. We report the presence of bovine IgGs in the germinal layer from infertile cysts (GLIC), in an order of magnitude greater than in the germinal layer from fertile cysts (GLFC). When extracted with salt solutions, bovine IgGs from GLIC are associated with low or with high affinity (most likely corresponding to non specific and antigen specific antibodies, respectively). Specific IgGs penetrate both the cells of the germinal layer and HeLa cultured cells and recognize parasitic proteins. These results, taken together with previous ones from our laboratory, showing induction of apoptosis in the germinal layer of infertile hydatid cysts, provide the first coherent explanation of the infertility process. They also offer the possibility of identifying the parasite antigens recognized, as possible targets for immune modulation.