Differential proteome between ejaculate and epididymal sperm represents a key factor for sperm freezability in wild small ruminants

Epididymal sperm shows higher cryoresistance than ejaculated sperm. Although the sperm proteome seems to affect cell cryoresistance, studies aiming at identifying proteins involved in sperm freezing-tolerance are scarce. The aims of this study were to investigate differences of sperm freezability and proteome between epididymal and ejaculated sperm in three mountain ungulates: Iberian ibex, Mouflon and Chamois. Sperm samples were cryopreserved in straws by slow freezing. Tandem mass tag-labeled peptides from sperm samples were analyzed by high performance liquid chromatography coupled to a mass spectrometer in three technical replicates. The statistical analysis was done using the moderated t-test of the R package limma. Differences of freezability between both types of sperm were associated with differences of the proteome. Overall, epididymal sperm showed higher freezability than ejaculated sperm. Between 1490 and 1883 proteins were quantified in each species and type of sperm sample. Cross species comparisons revealed a total of 76 proteins that were more abundant in epididymal than in ejaculated sperm in the three species of study whereas 3 proteins were more abundant in ejaculated than epididymal sperm in the three species of study (adjusted P < 0.05; |log₂| fold-change > 0.5). Many of the proteins that were associated with higher cryoresistance are involved in stress response and redox homeostasis. In conclusion, marked changes of sperm proteome were detected between epididymal and ejaculated sperm. This work contributes to update the sperm proteome of small ruminants and to identify candidate markers of sperm freezability.

High rate of revision and a high incidence of radiolucent lines around Metasul metal-on-metal total hip replacements: results from a randomised controlled trial of three bearings after seven years

A total of 397 hips were randomised to receive Metasul metal-on-metal (MoM), metal-on-conventional polyethylene (MoP) or ceramic-on-polyethylene (CoP) bearings using a cemented triple-tapered polished femoral component (MS-30). There were 129 MoM hips in 123 patients (39 male and 84 female, mean age 63.3 years (40.7 to 72.9)), 137 MoP hips in 127 patients (39 male and 88 female, mean age 62.8 years (24.5 to 72.7)) and 131 CoP hips in 124 patients (51 male and 73 female, mean age 63.9 years (30.6 to 73.8)). All acetabular components were cemented Weber polyethylene components with the appropriate inlay for the MoM articulation. Clinical evaluation was undertaken using the Harris hip score (HHS) and radiological assessments were made at two, five and seven years. The HHS and radiological analysis were available for 341 hips after seven years. The MoM group had the lowest mean HHS (p = 0.124), a higher rate of revision (p < 0.001) and a higher incidence of radiolucent lines in unrevised hips (p < 0.001). In all, 12 revisions had been performed in 12 patients: eight in the MoM group (four for infection, four for aseptic loosening, three in the MoP group (one each of infection, dislocation and pain) and one in the CoP group (infection). Our findings reveal no advantage to the MoM bearing and identified a higher revision rate and a greater incidence of radiolucent lines than with the other articulations. We recommend that patients with a 28 mm Metasul MoM bearing be followed carefully.