Longitudinal study of semen quality of unexposed workers. Sperm motility characteristics.

As part of a longitudinal study of human semen characteristics of unexposed workers, sperm motility measurements were made using computer-assisted sperm analysis. Motility analyses were conducted on monthly samples from 46 men for 9 months. Measurements of curvilinear velocity, straight-line velocity (VSL), linearity, amplitude of lateral head displacement (ALH), and beat-cross frequency were collected in eight microscope fields for each semen sample. The variability within a sample, between samples from the same individual (between monthly samples), and between individuals were calculated using a nested analysis of variance. For all sperm motility measurements, at least 90% of the variation was observed between cells within a semen sample. For all variables, the component of variation between subjects was the smallest percentage (ranging from 1.3% for ALH to 4.0% for VSL). When sample means were used in the nested analysis of variation, at least 75% of the variation was observed between samples from the same individual. These results will be useful in power calculations for future studies.

Longitudinal study of semen quality of unexposed workers: sperm head morphometry.

As part of a longitudinal study of human semen characteristics of unexposed workers, sperm head measurements were made using image analysis (Image Technologies Corp., Deer Park, NY). Morphometry was conducted on monthly samples from 45 men for 9 months. Measurements of area, perimeter, length, width, the width-length ratio, and the oval factor (4 [pi] area/perimeter) of 100 sperm heads per sample were obtained. The variability within a sample, between monthly samples from the same individual, and between individuals were calculated for each parameter. Tolerance intervals for each parameter were calculated, and are expected to contain 75% of all individual measurements. Similar intervals were calculated for the means and coefficients of variation of a semen sample. The largest source of variability was attributed to individual cell variation within a semen sample.

The effects of ethylene dibromide on semen quality: a comparison of short-term and chronic exposure.

Two occupational field studies were conducted to determine the effects of ethylene dibromide (EDB) exposure on male reproductive potential. The first study was a longitudinal study of 10 EDB-exposed forestry employees and 6 unexposed men conducted in Colorado in the summer of 1983. The exposure time was approximately 6 weeks. The second study was a cross-sectional study of 46 EDB-exposed papaya workers and 43 unexposed men conducted in Hawaii in December 1983 in which the average term of employment was about 5 years. In the longitudinal study, sperm velocity decreased in all 10 exposed men and in only two unexposed men. Semen volume was also decreased in 9 of the 10 exposed men (there was no change in the other man); only two unexposed men had a decrease in their semen volume. The longer term EDB exposure resulted in decreases in sperm motility and viability, suggesting that the short term exposure may slow sperm velocity, but longer exposures cause immotility and cell death. An apparent decrease in semen volume that was observed in the longitudinal study was not statistically significant in the cross sectional study of workers having chronic exposure. However, a significantly higher semen pH was observed in the exposed men compared to the unexposed men in the cross-sectional study. The results from both studies suggest that the accessory sex glands may be affected by EDB exposure.

Longitudinal study of semen quality of unexposed workers. I. Study overview.

A longitudinal study of 45 men was conducted evaluating the semen quality of monthly samples collected over 9 months. The statistical variation of sperm count, semen volume, percentage of motile sperm, sperm velocity, sperm morphology, and sperm viability, assessed by both the vital stain and the hypoosmotic swelling (HOS) assay, were each evaluated using intraclass correlations and coefficients of variation. Sperm count and semen volume had large intraclass correlations (62% and 60%, respectively), indicating that if a subject has a high count or volume he will tend to continue to have high counts or volumes. On the other hand, sperm velocity had an intraclass correlation of only 16% indicating that fluctuations within a subject were nearly as large as fluctuations from subject to subject. The remaining parameters had intraclass correlations ranging from 42% to 47%. Sperm count, percent motile sperm, and semen volume each had large coefficients of variation (both between and within subjects). These variables, especially count, had relatively poor precision. Sperm velocity, percent motile sperm, percent normal morphology, the HOS assay, and the vital stain assay had lower coefficients of variation, indicating greater precision.

Semen analysis of military personnel associated with military duty assignments.

A collaborative study between the U.S. Army Biomedical Research and Development Laboratory (USABRDL) and the National Institute for Occupational Safety and Health (NIOSH) was designed to assess fecundity of male artillery soldiers with potential exposures to airborne lead aerosols. Potential exposure assessment was based upon information provided in an interactive questionnaire. It became apparent from extensive questionnaire data that many soldiers in the initial control population had potentially experienced microwave exposure as radar equipment operators. As a result, a third group of soldiers without potential for lead or microwave exposures, but with similar environmental conditions, was selected as a comparison population. Blood hormone levels and semen analyses were conducted on artillerymen (n = 30), radar equipment operators (n = 20), and the comparison group (n = 31). Analysis of the questionnaire information revealed that concern about fertility problems motivated participation of some soldiers with potential artillery or microwave exposures. Although small study population size and the confounding variable of perceived infertility limit the reliability of the study, several statistically significant findings were identified. Artillerymen who perceived a possible fertility concern demonstrated lower sperm counts/ejaculate (P = 0.067) and lower sperm/mL (P = 0.014) than the comparison group. The group of men with potential microwave exposures demonstrated lower sperm counts/mL (P = 0.009) and sperm/ejaculate (P = 0.027) than the comparison group. Variables used to assess endocrine, accessory sex gland, and sperm cell function were not different than the comparison group. Additional studies, incorporating larger numbers of individuals, should be performed in order to more optimally characterize potential lead and microwave exposure effects on male fecundity.

Individuality of DNA denaturation patterns in human sperm as measured by the sperm chromatin structure assay.

Eight monthly semen samples from 45 men not known to be exposed to industrial toxicants were measured by the flow cytometric sperm chromatin structure assay (SCSA). This assay determines susceptibility of sperm DNA to in situ, acid-induced denaturation and is quantitated by the metachromatic shift of acridine orange fluorescence from green (native DNA) to red (denatured DNA). The observed green versus red fluorescence scattergram (cytogram) patterns were generally unique between donors and homogeneous within a donor over time. Within a donor, the cytogram patterns were the same whether intact sperm cells or detached nuclei were measured. For some individuals the cytogram patterns differed for some months and then returned to the original pattern. Intraclass correlations for mean and standard deviation of alpha t [alpha t = red/(red + green) fluorescence] were higher (.67 to .90) than any classically measured semen variables, suggesting that SCSA results within an individual were more consistent than other measures. Furthermore, average within-donor CV of alpha t parameters expressed as a percent of any given individual's means was around 10%, which is significantly lower than those derived from common semen measures. The SCSA is an objective, technically sound, biologically stable, sensitive, and feasible measure of semen quality.

Laboratory methods for assessing human semen in epidemiologic studies: a consensus report.

It is clear that additional methodologic work needs to be performed. Some data gaps described above are being actively investigated. Other standards were not addressed at this meeting; statistical handling of the data, differences among CASA machines, and factors to consider as potential confounders in analysis are just a few. These may be the subject of future workshops, which will also review progress made in the existing knowledge base. For now, this effort represents a first attempt to share information and to use it to encourage investigators in different laboratories to employ similar methods. In this way more direct comparisons among studies can be made, and our collective data base can be strengthened.

Male reproductive effects of lead, including species extrapolation for the rabbit model.

The effects of elevated blood lead on semen quality were evaluated in the rabbit model and compared to published effects in humans. Mature, male rabbits were given lead acetate by subcutaneous injection in the dose range of 0 to 3.85 mg/kg on a Monday-Wednesday-Friday basis. In each of eight treatment groups, a dosing regimen was developed to produce blood lead levels of 0, 20, 40, 50, 70, 80, 90, and 110 microg/dL. A 5-week pre-exposure period was followed by a 15-week exposure testing period allowing for response through six cycles of the seminiferous epithelium. Semen analyses revealed that increased blood lead levels were associated with adverse changes in the sperm count, ejaculate volume, percent motile sperm, swimming velocities, and morphology. Hormonal responses were minimal. Testicular pathology revealed a dose-dependent inhibition of spermiation. For six measures of semen quality, threshold estimates ranged from 16 to 24 microg/dL. Using the species extrapolation factor derived in this study, a rabbit dose would have to be divided by 1.56 to obtain the equivalent human dose for an equal percentage decrease in sperm concentration; however, rabbits are 3.75 more sensitive in terms of absolute decrease in sperm count for a given blood lead level.

Reproductive function in relation to duty assignments among military personnel.

As a follow-up to the pilot study of semen quality of soldiers with various military assignments a larger, more complete study was conducted. Soldiers were recruited at Fort Hood, Texas. Thirty-three men were exposed to radar as part of their duty assignment in the Signal Corps, 57 men were involved with firing the 155 mm howitzer (potential lead exposure), and 103 soldiers had neither lead nor radar exposure and served as the comparison control group. Both serum and urinary follicle-stimulating hormone and luteinizing hormone and serum, salivary, and urine testosterone levels were determined in all men. A complete semen analysis was conducted on each soldier. For statistical analysis, the primary study variables were: sperm concentration, sperm/ejaculate, semen volume, percent normal morphology, percent motile, percent viable (both vital stain and hypoosmotic swelling), curvilinear velocity, straight-line velocity, linearity, sperm head length, width, area, and perimeter. Variables were adjusted for significant confounders (e.g., abstinence, sample age, race). No statistical differences (P < 0.05) were observed in any measurement. While these results are in agreement with two previous studies assessing soldiers firing the 155-mm howitzer, they contradict our previous report indicating that radar exposure caused a significant decrease in sperm numbers. A possible explanation is that the radar exposure in this study was that used in Signal Corps operations while the men in the previous study were using different radar as part of military intelligence operations. The data presented here in men firing the 155-mm howitzer combined with the results from the previous studies confirms that there are no deficits in semen quality in these men. The contradiction between the results of the radar exposure studies indicates that more data are needed to evaluate the relationship of military radar and male reproductive health.

Semen quality and hormone levels among radiofrequency heater operators.

Approximately 9,000,000 US workers are occupationally exposed to radiofrequency (RF) radiation; over 250,000 operate RF dielectric heaters. Our purpose was to determine whether male RF heater operators experience increased adverse reproductive effects reflected in reduced semen quality or altered hormone levels. We measured incident RF heater radiation exposures and RF-induced foot currents at four companies. For 12 male heater operators and a comparison group of 34 RF-unexposed men, we measured 33 parameters of semen quality and four serum hormones. Despite wide variation in individual exposure levels, near field strengths and induced foot currents did not exceed current standard levels and guidelines. We observed minor semen quality and hormonal differences between the groups, including a slightly higher mean follicle-stimulating hormone level for exposed operators (7.6 vs 5.8 mIU/mL). Further occupational studies of RF-exposed men may be warranted.

Two cases of junctional epidermolysis bullosa (Herlitz-Pearson).

Clinical details of one surviving and one fatal case of junctional epidermolysis bullosa, previously termed epidermolysis bullosa letalis-Herlitz, are reported and factors affecting prognosis are discussed.

Acne vulgaris.

A theory concerning the pathogenesis of acne vulgaris is offered and, based on the theory, a rationale for treatment is presented. Acne vulgaris should be regarded as a cosmetically unacceptable biological variation in most cases, a syndrome rather than a disease. One must not lose sight of the occasional case in which it is the marker of an endocrine disorder.

Microsporum nanum infection in South Australia.

Two cases of human ringworm caused by the dermatophyte Microsporum nanum are reported from South Australia. M. nanum is the commonest cause of ringworm in pigs and is known to cause porcine infections in Australia. This report shows the value of mycological investigations in determining the possible source of such infections.

Chemical and thermal effects on the viability and motility of spermatozoa from the turtle epididymis.

The viability and motility of spermatozoa harvested from the epididymides of turtles were estimated to elucidate properties that might enable them to be stored over long periods of time. Spermatozoa from the painted turtle, Chrysemys picta, were analysed and compared with spermatozoa from two other turtles, Trachemys scripta and Sternotherus odoratus using the Cellsoft analysis system for videotaped images. Spermatozoa from C. picta and T. scripta, suspended in F-10 medium, showed low motility (3-6% motile) and motion velocities, whereas the motility of spermatozoa from S. odoratus was higher (40% motile). Spermatozoa from C. picta and S. odoratus, but not T. scripta, had higher motilities and motion velocities when incubated at 2 degrees C before analyses. C. picta spermatozoa were unresponsive to calcium concentrations ranging from 10(-8) to 10(-1) mol l(-1), potassium concentrations ranging from 0. 1 to 10 mmol l(-1), and to pH values in the range 5.9-8.4. Spermatozoa from C. picta were sensitive to hypo-osmotic media, and showed reduced motility at 25% of normal osmolarity and no motility at 10% of normal osmolarity. Distorted cells and missing flagellae were noted at 50% of normal osmolarity. C. picta spermatozoa were viable up to 40 days after harvest when incubated at 4 degrees C; during this time, both motility and motion velocity were increased in response to 0.5 mmol 3-isobutyl-1-methylxanthine l(-1). Spermatozoa from turtles have osmotic properties and resistance to changing chemical environments similar to spermatozoa from other vertebrates that have internal fertilization, and appear to be stable over long periods of time compared with spermatozoa from other vertebrate species.

Erythema nodosum due to Pasteurella pseudotuberculosis.

Two children developed erythema nodosum due to Pasteurella pseudotuberculosis. Neither case showed typical signs of P. pseudotuberculosis infection, but this cause was shown by positive agglutination tests. It is suggested that this organism is a more common cause of erythema nodosum than is at present recognized.

A case of junctional epidermolysis bullosa (Herlitz-Pearson) with corneal bullae.

A proven case of junctional epidermolysis bullosa is presented in which there have been recurrent right and left corneal lesions. The corneal changes arose either spontaneously or after minor trauma. We have no histological findings of the cornea at present, but the clinical features are similar to those reported in epidermolysis bullosa dystrophica-recessive. We believe that this is the first detailed case report of corneal involvement in proven junctional epidermolysis bullosa. The literature is reviewed.