Semen

About: Semen is a research topic. Over the lifetime, 14571 publications have been published within this topic receiving 407739 citations. The topic is also known as: come & ejaculate.

Surface localization of P34H an epididymal protein, during maturation, capacitation, and acrosome reaction of human spermatozoa.

Abstract: During epididymal transit, spermatozoa acquire new surface antigens that are involved in the acquisition of their fertilizing ability. We have previously described a 34-kDa (P34H) human epididymal sperm protein that shows antigenic and functional homologies with the hamster P26h. P34H is localized on the acrosomal cap of human spermatozoa and has been proposed to be involved in the interaction with the zona pellucida. The aim of this study was to document the expression of P34H on the sperm surface during transit along the male and female genital tracts. Immunohistochemical techniques were performed on human testes and epididymides by means of an antiserum specific for P34H. No labelling was detected on those spermatozoa found within the seminiferous tubules or in the vasa efferentia. P34H first appeared in the caput epididymidis and was restricted to the acrosomal cap. Signal intensity then increased considerably from the proximal corpus to the cauda region of the epididymis. After ejaculation, the same pattern of P34H distribution was observed, but the intensity was much lower than that characterizing the cauda epididymal spermatozoa. Strong labeling was restored after incubation in B2 medium and was maximal after 5 h of capacitation. After acrosomal exocytosis induced by a Ca2+ ionophore, the percentage of P34H-labeled spermatozoa decreased proportionally to the number of acrosome-reacted spermatozoa as determined by Pisum sativum-fluorescein isothiocyanate (FITC) labeling. P34H appeared to be strongly anchored to the sperm plasma membrane during epididymal transit as indicated by the requirement for detergent to extract this surface antigen from ejaculated spermatozoa. This confirms the importance of P34H binding to the sperm plasma membrane during epididymal maturation. We have previously proposed that P34H is involved in sperm-zone pellucida interaction. The appearance and accumulation of P34H on the sperm plasma membrane during epididymal maturation, followed by its inaccessibility associated with ejaculation, its unmasking during capacitation, and finally its elimination after the acrosome reaction, are in agreement with te proposed function of this sperm antigen.

Poor sperm quality and advancing age are associated with increased sperm DNA damage in infertile men.

Abstract: With increasing evidence for faulty paternal contribution to reproduction, there has been a steady increase in studies highlighting an association between sperm DNA damage, failed/delayed fertilisation and aberrant embryo development. Owing to prevailing ambiguity, the aims of the study were to analyse the genetic integrity of the male gamete and then to understand its association with age, standard semen parameters, lifestyle and occupational factors. The study included 504 subjects, attending university infertility clinic for fertility evaluation and treatment. Semen characteristics were analysed by standard criteria; terminal deoxynucelotidyl transferase-mediated nick end-labelling assay was employed for DNA damage assessment. The average incidence of sperm DNA damage in patients with normozoospermic semen parameters was <10%. Patients with oligozoospermia, severe oligozoospermia, oligoasthenoteratospermia, asthenoteratozoospermia and necrozoospermia had significantly higher level of sperm DNA damage (P < 0.001). Patients above 40 years of age had significantly high levels of DNA damage (P < 0.001) compared with their counterparts. Patients with varicocele and a history of alcohol consumption had higher incidence of spermatozoa with DNA damage (P < 0.01). Poor sperm characteristics in the ejaculate are associated with increased sperm DNA damage. Age-related increase in sperm DNA damage and association of the same with varicocele and alcohol consumption are also demonstrated.

Detection of human herpesvirus 8 DNA sequences in tissues and bodily fluids

Abstract: Human herpesvirus 8 (HHV-8) has been proposed as a sexually transmitted etiologic agent of Kaposi’s sarcoma (KS). In this study, by use of a sensitive polymerase chain reaction assay, HHV-8 DNA was detected in the skin lesions (92%), normal skin (23%), peripheral blood mononuclear cells (PBMC) (46%), plasma (7%), saliva (37%), and semen (12%) but not stool samples from KS patients. The average number of HHV-8 copies per microgram of positive target DNA was 64,000, 9000, 40, 33,000, and 300 for skin, PBMC, plasma, saliva, and semen samples, respectively. Only 1 non-KS donor sample, of saliva, was positive for HHV-8. Sequencing showed 5% divergence among HHV-8 strains. The data suggest that saliva may be more important than semen or stool in the sexual transmission of HHV-8. The relatively high prevalence of HHV-8 in PBMC raises the question as to why there is no evidence for bloodborne virus transmission. Kaposi’s sarcoma (KS) occurs as a mild indolent disease in immunocompetent persons but is an aggressive, lethal disease in immunosuppressed patients, particularly those infected with human immunodeficiency virus (HIV) [1]. Epidemiologic studies suggest that KS is a sexually transmitted disease caused by the newly discovered human herpesvirus 8 (HHV-8) [1, 2]. Subsequently, HHV-8 has been shown to be associated with numerous other tumors, including body cavity lymphomas, angiosarcomas and hemangiomas, premalignant Bowen’s disease, malignant squamous cell carcinomas, and actinic keratosis [2]. HHV-8 positivity has been shown to be more closely linked to HIV-positive patients with homosexuality or bisexuality as their major risk factor for HIV than to patients with other risks [2]. Hence, it has been suggested that HHV-8 may be a sexually transmissible virus, particularly via anal intercourse. The fact that HHV-8 can be found in semen samples and in individual spermatozoa and mononuclear cells present in semen has supported this hypothesis [3]. However, in large-scale or smaller matched studies, the prevalence of HHV-8 in semen has been equal to or less than that found in peripheral blood mono