The Andrology Laboratory in an Assisted Reproductive Technologies Program

Computer‐aided sperm analysis (CASA) technology is 7 years old. Over 120 papers have been written that verify the technology or apply it in basic and clinical studies. Most of the technical problems with CASA, such as the dependence of velocity on video frame rate, inaccuracy of count and percent motility for low‐ and high‐concentration specimens, parameter dependence on the number of frames analyzed, sensitivity of the subjective threshold setting, confusion over the presence of debris, and different implementations of algorithms across instruments, still persist. A critical review of the literature reveals that no standard practices are followed within or across instruments. Moreover, no standards have been embraced or recommended by professional societies. Despite its potential to provide objective measurements of specimen and individual sperm parameters, and to automate the laboratory semen analysis, the promise of CASA has not been fulfilled. Unless laboratory medicine defines instrument performance and laboratory standards and co‐operates with industry to achieve these goals, CASA technology may remain a research curiosity. This outcome is especially worri‐some in the context of increasing requirements for laboratory accuracy, precision, standardization, and accreditation under the Clinical Laboratory Improvement Act of 1988.

Operational Standards for CASA Instruments

DAVIS,

KATZ

1993

CapacitationIn Vitroof Stallion Spermatozoa: Comparison of Progesterone‐Induced Acrosome Reactions in Fertile and Subfertile Males

Meyers

Overstreet

Liu

et al. 1995

Mammalian sperm that have completed capacitation are capable of undergoing the acrosome reaction in response to a number of biological and chemical stimuli. In the present report, we have investigated the ability of progesterone to stimulate acrosome reactions of stallion sperm capacitated in vitro. Motile sperm were selected by a two‐layer Percoll gradient centrifugation and were incubated in TALP medium modified by the 1:1 (v/v) addition of TEST‐yolk medium for 5 hours at 39°C, under 5% CO2 in humidified air. Sperm incubated in vitro in TALP‐TEST medium had a higher percentage of acrosome reactions following the addition of progesterone (3.18 μmol/L) compared to controls (P < 0.05). Furthermore, sperm from stallions classified as fertile on the basis of breeding history had higher percentages of progesterone‐induced acrosome reactions in comparison with stallions classified as subfertile (P < 0.05). Acrosome reactions were assessed routinely by fluoresceinated lectin binding, but the physiological appearance of induced acrosome reactions was confirmed at the ultrastructural level by transmission electron microscopy. We conclude that 1) TALP‐TEST medium supports stallion sperm capacitation in vitrot 2) progesterone‐induced acrosome reactions are physiological, and 3) sperm from fertile stallions may be more responsive to progesterone‐induced acrosome reactions than those of subfertile stallions. This is the first report in a nonhuman species that differences exist between the sperm of fertile and subfertHe males in the ability to capacitate and acrosome react in vitro. These data suggest that some cases of stallion sperm dysfunction may have a molecular etiology and that tests of sperm function, such as response to in vitro capacitation and agonists of the acrosome reaction, may be useful in evaluation and therapy of stallion subfertility.

Evidence of Proacrosin Molecule Abnormality as a Possible Cause of Low Acrosin Activity and Unexplained Failure of Fertilization In Vitro

SHIMIZU,

KODAMA,

FUKUDA

et al. 1997

The aim of this study was to investigate whether the molecular abnormality of proacrosin is associated with an unexplained failure of in vitro fertilization (IVF) and low acrosin activity in human infertility. Seventeen infertile men, whose spermatozoa appeared to be normal but did not fertilize using a conventional IVF technique, were included in this study. Proacrosin molecules from each patient were screened with electrophoresis and Western blotting using either anti‐human proacrosin or anti‐boar acrosin polyclonal antibodies. The bands of proacrosin appeared equally on the sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) at an identical site and reacted equally with human proacrosin antibodies in all patients studied. The anti‐boar acrosin antibodies cross‐reacted with the proacrosin bands of the patients in all but two cases. The two patients also demonstrated lower levels of total acrosin activity and different peptide maps of the isolated proacrosin. In conclusion, the molecular abnormality of proacrosin, which is reflected by a lack of cross‐reactivity to the anti‐boar acrosin antibodies, is associated with low acrosin activity and may explain some cases of unexplained failure of human IVF treatment.