Testing androgen-induced immunosuppression: Environmental androgens as a model system for steroid-immune interaction.

It is well known that hormones influence and direct most facets of physiology; however, there is still contention regarding the directions of certain relationships, for example, between gonadal hormones and immunity. Among the many proposed relationships relating to gonadal-immune interactions, support for immunosuppressive effects of androgens remains prominent within physiological literature. Although ample study has been directed toward the immunosuppressive effects of androgens, considerable disagreement remains regarding their influence on immune function. In this study, we test the hypothesis that androgens inhibit immunocompetence in the American alligator (Alligator mississippiensis). Developing alligators were incubated at female-producing temperatures with a subset of individuals being exposed to 17-α-methyltestosterone (MT) before sexual determination. 17-α-methyltestosterone is a potent androgen, not aromatizable by crocodilians, that has been found to exert masculinizing effects in exposed crocodilian populations in vivo and in vitro. Additionally, a subset of animals was exposed to a novel antigen to quantify innate and acquired immune function. We recovered no significant differences in leukocyte ratios or proportions between groups and found no significant differences in innate immune function as measured by hemolysis-hemagglutination. However, we did find significant differences in acquired immune function, where masculinized individuals expressed greater antibody titers. Our findings reject the hypothesis that androgens suppress immune function; rather, androgens may be immunoenhancing to acquired humoral responses and neutral to innate humoral immunity in crocodilians.

The Inference of the Evolution of Immune Traits as Constrained by Phylogeny: Insight into the Immune System of the Basal Diapsid.

Among vertebrates, some of the most vulnerable taxa to emergent fungal pathogens are members of Reptilia. In light of the growing threat of emergent fungal pathogens affecting wildlife, it is important to broaden the current understanding of immune system function, development, and evolution. The homologous condition of a trait is necessary in order to study its evolution, as such, homology is necessary in the study of immunological evolution. Here, we explore the evolution of toll-like receptors (TLRs), a series of homologous receptors crucial to the initial immune response. The homologous condition of TLR genes provides a unique system in which to explore the evolution of the TLR; using a Reptilian phylogeny, we elucidate the immune condition of the basal diapsid. Our analysis revealed that the basal diapsid may have had an immune system that lacked two receptors: TLR 15, a receptor uniquely present in Reptilia, and TLR 13, a receptor important in the recognition of nucleic acid motifs. Additionally, our analysis showed multiple losses and convergences for various TLRs, likely attributed to redundancies in receptor function. Further exploration into the immune condition of extinct taxa may shed light on the evolution of the reptilian immune system.

Sex-based trade-offs in the innate and acquired immune systems of Sternotherus minor.

Longevity patterns in most vertebrates suggest that females benefit most from maintenance investment. A reversed longevity pattern in loggerhead musk turtles (Sternotherus minor) allowed us to test trade-offs between maintenance and survivorship. We tested the hypothesis that the sex with greater longevity has greater maintenance than the sex with shorter longevity. We also compared the following parameters between sexes: Bactericidal ability (BA) and heterophil:lymphocyte ratios (HLR). Baseline blood samples were collected from turtles in the field; a subset of turtles was returned to a laboratory for experiments of acquired immune responses to sheep red blood cells (SRBC). We found no support for the original hypothesis of reversal in sex-dependent immune trade-offs (difference between sex SRBC titers: p = .102; interaction between treatment and sex: p = .177; difference between treatments: p < .001; effect of sex on BA: p = .830; effect of sex on HLR: p = .717). However, we did find support for sex-dependent differences in immunity in the relationship between HLR and body condition (BCI) (effect of BCI on HLR: p = .015). In field conditions, we found that males with higher body condition indices express stressed phenotypes more than males with lower body condition indices (p = .002). However, females expressed similar stress loads across all body conditions (p = .900). Testosterone concentrations were assayed in free-living turtles and were not related to any of the immune parameters. Our results suggest that the immune systems play an important role in balancing sex-specific responses to different selective pressures in S. minor.

Seguimiento a cuatro años de pacientes con stent / Firebird liberador de sirolimus en Cuba

Se realizó un estudio descriptivo, longitudinal prospectivo, multicéntrico nacional, en Cuba, con la participación del Instituto de Cardiología y Cirugía Cardiovascular, el Centro de Investigaciones Médico Quirúrgicas y el Hospital Hermanos Ameijeiras. El objetivo fue caracterizar el seguimiento clínico y angiográfico a largo plazo de los pacientes a los que se implantó stent Firebird® liberador de sirolimus (rapamycin), de fabricación china, en el período comprendido entre enero de 2006 y agosto de 2008. Material y método: se implantaron 69 endoprótesis en 52 pacientes. Se utilizaron distribuciones de frecuencia, medidas de tendencia central, cálculos porcentuales, odds ratio y chi cuadrado, así como curva de Kaplan-Meier. Resultados: a los 8 meses se documentó reestenosis del stent en el 7,7 por ciento de los pacientes reestudiados. La mortalidad y la tasa de reestenosis en la población estudiada fueron realmente bajas. No hubo trombosis tardías ni muy tardías del stent. Las oclusiones totales crónicas y las nuevas lesiones con criterios de revascularización incrementaron el riesgo de eventos cardiovasculares mayores. Conclusiones: el uso del stent Firebird® liberador de sirolimus en la población estudiada fue seguro, con una supervivencia libre de eventos mayores cardiovasculares significativamente importante(AU)

This is a descriptive, longitudinal prospective, a Cuban multicenter study with the participation of the Institute of Cardiology and Cardiovascular Surgery, the Center of Investigations Surgical Medical, and the Clinical Surgical Hospital Hermanos Ameijeiras.The aim of this research was to characterize the clinical and angiographic monitoring patients who were implanted with the chinese Firebird® drug-eluting stent (rapamycin). Material and method. A total of 52 patients were implanted with 69 of these stents, from January 2006 to August 2008. In order to study the survival analysis, frequency distributions, central tendencies, percentage calculations, odds ratios, chi-square, and the Kaplan-Meier curve were used. Results. After eight months, 7.7 percent of the patients were documented with stent restenosis. Mortality and restenosis rates were low. This research did not find late and very late thrombosis. The chronic total occlusions and the new lesions with revascularization approaches increased the risk of major cardiovascular events.Conclusions. The use in Cuba of the Firebird® sirolimus-eluting stent was safe, with a MACE free survival significantly high(AU)