PMC

Lateral meniscus tears defined as major tears. Root tears (defined as avulsion of the meniscus root (A) or complete radial/oblique radial tears within one centimeter from the bony insertion of the lateral meniscus (B)); radial split tears (C) and unstable longitudinal tears including bucket-handle tears (D).

(A) IP of mucin MUC5AC. Tears (100 μl) were immunoprecipitated with anti-MUC5AC antiserum or goat preimmune serum and electrophoresed on a 4 to 15% gradient gel for MUC5AC immunodetection. Lane 1, nontreated tears; lane 2, anti-MUC5AC antiserum immunoprecipitate; lane 3 residual tears after anti-MUC5AC IP; lane 4, preimmune goat serum immunoprecipitated pellet; lane 5, residual tears after preimmune goat serum IP. Representative data from one of three experiments are shown. (B) Antimicrobial activity of hBD-2 in tears in the presence and absence of MUC5AC. A total of 10⁷ CFU/ml P. aeruginosa (ATCC 27853) was incubated with hBD-2 (100 μg/ml), hBD-2 with 70% (vol/vol) tears (hBD-2 + Tears), hBD-2 with 70% (vol/vol) anti-MUC5AC immunoprecipitated tears [hBD-2 + IP Tears (no MUC5AC)], or hBD-2 with 70% (vol/vol) goat preimmune serum immunoprecipitated tears [hBD-2 + IP tears (with MUC5AC)] at 37°C for 2 h. Mean data from five experiments, expressed as the percentage of bacteria killed by hBD-2, are shown. (C) Direct interaction of hBD-2 and MUC5AC in human tears. Tears (50 μl) preincubated with hBD-2 (100 μg/ml) were immunoprecipitated with anti-hBD-2 polycolonal antibody or rabbit serum and electrophoresed on a 4 to 15% gradient gel for MUC5AC immunodetection. Lane 1, nontreated tears; lane 2, anti-hBD-2 antibody immunoprecipitated pellet; lane 3, rabbit serum immunoprecipitated pellet.

Chemosignaling effects of tears replicate across species and studies. (a) Mole-rats that cover themselves with their own tears are attacked less frequently by dominant males. Adapted from (Shanas & Terkel, ). (b) Replication across species: Mouse pups covered with a peptide in tears are subject to less sexual behaviour by adult males. Adapted from (Ferrero et al., ). (c) Sniffing emotional tears obtained from women reduced free testosterone in men. Adapted from (Gelstein et al., ). (d) A replication within species: Sniffing emotional tears obtained from women reduced free testosterone in men. Adapted from (Oh et al., ). (e) Sniffing women’s emotional tears reduced the sexual attractiveness attributed by men to pictures of sad women’s faces. Adapted from (Gelstein et al., ). (f) A replication within species: Sniffing women’s emotional tears reduced the sexual attractiveness attributed by men to a picture of a woman. Adapted from Gračanin et al. Experiment 3, ratings of picture #14. (g) A replication within species: Sniffing women’s emotional tears reduced the sexual attractiveness attributed by men to pictures of women. Trigeminal tears failed to induce the same effect. Adapted from Gračanin et al. Experiment 2, Sample 1.