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Presents a study that examined a laboratory experience in teaching pool-based electricity markets to power engineering students. Discussion on the main objective of an electricity market; Details on the use of a market simulator and a computer communication network in simulating the actual functioning of an electricity market; Results and implications.

The presence of the 60 kDa heat shock protein (hsp60) in seminal fluid and its relationship to sperm autoimmunity or a localized immune response to Chlamydia trachomatis were examined. Semen from 64 male partners of infertile couples with no history of a chlamydial infection were investigated. Hsp60 was identified by an enzyme-linked immunosorbent assay (ELISA) using a monoclonal anti-hsp60 antibody bound to wells of a microtitre plate and a polyclonal anti-hsp60 antibody for detection. Antisperm antibodies on motile spermatozoa were detected by immunobead binding, while antichlamydial immuno-globulin (Ig) A and IgG in seminal fluid were identified by a commercial ELISA (SeroELISA; Savyon Diagnostics, Beer-Sheva, Israel). RNA was purified from isolated seminal round mononuclear cells and tested for hsp60-specific mRNA by a reverse transcription polymerase chain reaction ELISA. Hsp60 was present in semen from nine (14.1%) men, 12 (18.8%) men had antisperm autoanti-bodies, 16 (25.0%) were positive for antichlamydial IgA and 17 (26.6%) had detectable hsp60-specific mRNA. The presence of hsp60 in semen correlated with the occurrence of antichlamydial IgA (P = 0.0005), hsp60 mRNA (P = 0.04) and antisperm antibodies (P = 0.05). Thus, hsp60 was present in a soluble form in semen primarily in men with evidence of immune system activation within their genital tract. The role of hsp60 in promoting or inhibiting immune responses within the genital tract remains to be determined. [ABSTRACT FROM PUBLISHER]

The relationship between an undetected, asymptomatic Chlamydia trachomatis genital tract infection, the concentration of γδ and αb T cells in semen and sperm autoimmunity was examined in 48 male partners of couples with unexplained infertility. Immunoglobulin A (IgA) antibodies to were detected in seminal fluids from 14 (29.2%) of the men. Only four of these were positive for circulating anti-chlamydial IgA, suggesting that the stimulus for antibody production was within the genital tract. In contrast, four men were positive for anti-chlamydial IgG in their semen; all were also seropositive for anti-chlamydial IgG. T lymphocytes bearing the αβ and γδ antigen receptors were present in every semen sample. Men with seminal anti-chlamydial IgA, however, had significantly ( = 0.035) elevated semen γδ T cell concentrations (median 3100 cells/ml) than did men lacking this antibody (median 1400 cells/ml); concentrations of αβ T cells were comparable in both groups. Genital tract sperm autoimmunity, as shown by antibodies bound to motile ejaculated spermatozoa, was detected in 13 (27.1%) men. The presence of these antibodies was associated with elevated concentrations of both γδ (median 4200 versus 700 cells/ml) and αβ (median 5000 versus 850 cells/ml) T cells ( = 0.0002 and 0.0001 respectively). Men with antisperm antibodies only in their serum had seminal T cell concentrations comparable with men testing negative for antisperm antibodies. Anti-chlamydial IgA was identified in semen from four of 10 men with IgA bound to their spermatozoa and in none of the men with only spermatozoabound IgG. There was no relationship between sperm quality and the occurrence of seminal IgA antibodies to either or spermatozoa. An asymptomatic infection activates γδ T cells within the male genital tract, which may lead to antisperm antibody formation and immune-mediated infertility. [ABSTRACT FROM PUBLISHER]