Seasonal Variation and Sexual Dimorphism of the Microbiota in Wild Blue Sheep (Pseudois nayaur).

Microbiota of the wild blue sheep (Pseudois nayaur) presents a seasonal variation due to different dietary selection and feeding strategies from different ecological niches chosen by different sex in summer. To address those issues, we analyzed the variation of gut microbiota based on the material from the feces, with 16S rRNA and meta-genome aimed to explore seasonal and gender differences. The results indicate that seasonal dietary changes and gender differentiation, as expected, cause the variation in sheep's gut microbiota structure. The variation of the former is more significant than the latter. Dominant Firmicutes exists a significantly higher abundance in summer than that in winter. Subordinate Bacteroides expresses no seasonal difference between the two seasons. Compared with the winter group, the summer group is featured by abundant enzymes digesting cellulose and generating short-chain fatty acids (SCFAs), such as beta-glucosidase (EC: 3.2.1.21) for cellulose digestion, and butyrate kinase (EC:2.7.2.7) in butyrate metabolism, implying that the changes of the composition in intestinal flora allow the sheep to adapt to the seasonalized dietary selection through alternated microbial functions to reach the goal of facilitating the efficiency of energy harvesting. The results also show that the blue sheep expresses a prominent sexual dimorphism in the components of gut microbiota, indicating that the two sexes have different adaptations to the dietary selection, and demands for physical and psychological purposes. Thus, this study provides an example of demonstrating the principles and regulations of natural selection and environmental adaptation.

Value of transrectal ultrasonography in female traumatic urethral injuries.

OBJECTIVES: To estimate the value of transrectal ultrasonography (TRUS) in traumatic urethral injuries of various types in females. METHODS: A total of 30 female patients with symptoms of urethral injuries after trauma underwent TRUS between January 2005 and July 2008. Of them, 28 patients with operative indications undertook operation; the other 2 received conservative management and then a follow-up ultrasonography. All outcomes were used to validate the results of TRUS. RESULTS: Urethral injuries were clearly observed in 30 cases with TRUS. The continuity of urethral wall, unblocking of urethral lumen, and homogeneous echo of surrounding structures had been changed. Urethral injuries varied in types, including urethrovaginal fistula, urethral stricture, urethral rupture, and urethral hematoma. It was common to find several injury patterns simultaneously in 1 patient. The outcomes in 28 cases with operative indications were consistent with results of surgery. The other 2 cases were diagnosed as urethral hematoma by TRUS which disappeared in a follow-up sonography after 3 months' conservative management. CONCLUSIONS: TRUS is a reliable technique to exhibit abnormalities in injured urethra associated with trauma in female.

Persistent memory CD4+ and CD8+ T-cell responses in recovered severe acute respiratory syndrome (SARS) patients to SARS coronavirus M antigen.

The membrane (M) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) is a major glycoprotein with multiple biological functions. In this study, we found that memory T cells against M protein were persistent in recovered SARS patients by detecting gamma interferon (IFN-gamma) production using ELISA and ELISpot assays. Flow cytometric analysis showed that both CD4+ and CD8+ T cells were involved in cellular responses to SARS-CoV M antigen. Furthermore, memory CD8+ T cells displayed an effector memory cell phenotype expressing CD45RO- CCR7- CD62L-. In contrast, the majority of IFN-gamma+ CD4+ T cells were central memory cells with the expression of CD45RO+ CCR7+ CD62L-. The epitope screening from 30 synthetic overlapping peptides that cover the entire SARS-CoV M protein identified four human T-cell immunodominant peptides, p21-44, p65-91, p117-140 and p200-220. All four immunodominant peptides could elicit cellular immunity with a predominance of CD8+ T-cell response. This data may have important implication for developing SARS vaccines.

Long-lived effector/central memory T-cell responses to severe acute respiratory syndrome coronavirus (SARS-CoV) S antigen in recovered SARS patients.

The role of cell-mediated immunity in human SARS-CoV infection is still not well understood. In this study, we found that memory T-cell responses against the spike (S) protein were persistent for more than 1 year after SARS-CoV infection by detecting the production of IFN-gamma using ELISA and ELISpot assays. Flow cytometric analysis showed that both CD4(+) and CD8(+) T cells were involved in cellular responses against SARS-CoV infection. Interestingly, most of SARS-CoV S-specific memory CD4(+) T cells were central memory cells expressing CD45RO(+) CCR7(+) CD62L(-). However, the majority of memory CD8(+) T cells revealed effector memory phenotype expressing CD45RO(-) CCR7(-) CD62L(-). Thus, our study provides the evidence that SARS-CoV infection in humans can induce cellular immune response that is persistent for a long period of time. These data may have an important implication in the possibility of designing effective vaccine against SARS-CoV infection, specifically in defining T-cell populations that are implicated in protective immunity.