Headless spermatozoa in semen specimens from fertile and subfertile men
Division of Endocrinology and Human Reproduction, 2nd Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Thessaloniki, Greece. The Journal of reproductive medicine
(Impact Factor: 0.7).
To investigate the frequency of headless, or unnucleated, spermatozoa, determine its percentage and evaluate its possible correlation with other semen parameters.
Semen specimens from 94 subfertile men, aged 24-53 years (mean +/- SD 33.3 +/- 6.3) and from 52 fertile men, aged 24-44 (33.3 +/- 4.1) were studied. Two semen specimens were examined from each individual, with a six- to eight-week interval. Sperm morphology was evaluated from Papanicolaou-stained smears, and the classification of abnormal sperm forms was made according to the guidelines of the World Health Organization.
The percentage of headless spermatozoa was 9.0% +/- 8.8 in subfertile and 2.7% +/- 3.1 in fertile men. Headless spermatozoa existed in semen specimens from 90% of subfertile and 70% of fertile men. Of subfertile men, 23.4% had headless spermatozoa at a higher percentage than the highest normal limit found in sperm smears from fertile men.
In some cases of subfertile men with a high percentage of headless spermatozoa, their infertility can be attributed to the cause of this morphological abnormality. Moreover, tails but not heads were found in semen specimens from subfertile and fertile men.
Available from: Hector Edgardo Chemes
- "Spermatozoa without heads ( " acephalic " , " decapitated " , " pin heads " ) can be detected in extremely small numbers in the semen of fertile men and can increase up to 10%–20% in subfertile patients (Chemes et al. 1987b; Panidis et al. 2001). They have been reported as the main seminal abnormality in some sterile men in whom 80%–100% of the sperm population is composed of acephalic forms and a few loose heads (LeLannou 1979; Perotti et al. 1981; Baccetti et al. 1984; Chemes et al. 1987b). "
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ABSTRACT: Fertilization in mammals occurs via a series of well-defined events in the secluded environment of the female reproductive tract. The mode of selection of the fertilizing spermatozoon nevertheless remains unknown. As has become evident during in vitro fertilization by sperm microinjection into the oocyte, abnormal spermatozoa can successfully fertilize oocytes. Under these extreme conditions, post-fertilization events, early embryonic development and implantation are significantly compromised indicating that the contribution of spermatozoa extends beyond sperm penetration. Microscopic identification of normal spermatozoa is a well-standardized procedure but insights into the mechanisms that lead to aberrant sperm differentiation and into the subcellular nature of sperm abnormalities have only recently begun to be obtained. The spermatozoon is the result of a complex development in which spermatid organelles give rise to various structural components with characteristic functions. Similar to other differentiated cells, the spermatozoon has a specific pathology that is most clearly identified by ultrastructural evaluation coupled with immunocytochemistry and molecular techniques. This multidisciplinary approach allows the precise characterization of sperm abnormalities, including structural, molecular and functional aspects. We summarize here studies of the physiopathology of spermiogenesis in two abnormal sperm phenotypes of infertile men: dysplasia of the fibrous sheath and acephalic spermatozoa/abnormal head-tail attachment. The characterization of the abnormalities of the tail cytoskeleton and centrioles has uncovered aspects of the subcellular basis of pathological spermiogenesis, has suggested experimental approaches to explore the nature of these anomalies and has opened the way for genetic studies that will ultimately lead to the design of the therapeutic tools of the future.
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ABSTRACT: In this study, the evaluation of the total number of morphological anomalies per 100 sperm was more reliable, as far as potential fertility is concerned than the concentration of sperm per milliliter, the percentage of motile sperm, and the percentage of sperm with normal or abnormal morphology. This parameter allows for discrimination between subfertile and fertile semen and therefore can help in the selection of men who require assisted reproduction techniques.
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