Semen analysis

About: Semen analysis is a research topic. Over the lifetime, 4909 publications have been published within this topic receiving 143225 citations.

Interrelationships between seminal parameters and sperm nuclear DNA damage before and after density gradient centrifugation: implications for assisted conception

Abstract: Background With an increase in the use of assisted reproduction technologies the requirements of the diagnostic semen analysis are constantly changing. Methods Spermatozoa from patients undergoing IVF were analysed by examining the conventional semen parameters and DNA/chromatin integrity, using in-situ nick translation (NT) and the Chromomycin A(3) fluorochrome, which indirectly demonstrates a decreased presence of protamine. Samples were examined before and after preparation using discontinuous density gradient centrifugation. Results Density gradient centrifugation enriched samples by improving the percentage of morphologically normal forms by 138% and sperm nuclear integrity by 450%. Sperm nuclear integrity as assessed by in-situ nick translation (NT) demonstrated a very clear relationship with sperm concentration, motility and morphology. Morphology correlated with fertilization rates of patients undergoing IVF, while NT values of the spermatozoa post-preparation were significantly lower in pregnant patients. Conclusions We have demonstrated that along with the classical semen parameters, the assessment of nuclear integrity improves the characterization of the semen sample and may be used as a tool for allocating patients to specific assisted reproduction treatments.

Cryopreservation of domestic animal sperm cells

Abstract: Sperm cells are the endpoint of male spermatogenesis and have particular anatomic and metabolic features. Sperm cryopreservation and storage currently require liquid nitrogen or ultralow refrigeration methods for long or short term storage, which requires routine maintenance and extensive space requirements. Conserving sperms have several purposes such as artificial reproductive technologies (ART), species conservation and clinical medicine. The combinations of storage temperature, cooling rate, chemical composition of the extender, cryoprotectant concentration, reactive oxygen species (ROS), seminal plasma composition and hygienic control are the key factors that affect the life-span of spermatozoa. Sperm preservation protocols vary among animal species owing to their inherent particularities that change extenders used for refrigeration and freezing. Extenders for freezing sperm cells contain buffers, carbohydrates (glucose, lactose, raffinose, saccharose and trehalose), salts (sodium citrate, citric acid), egg yolk and antibiotics. The use of different cryoprotectants, like trehalose or glycerol, as well as different concentrations of egg yolk and other constituents in semen extenders are being studied in our laboratory. Several cooling rates have been tested to freeze sperm cells. The use of faster rates (15-60 degrees C/min) gives rise to best sperm survivals after freezing-thawing, but more studies are needed to find the adequate cooling rates for each animal species. Sheep and goat males of some native breeds are being used in studies performed in EZN. Semen from those males has been frozen and stored as part of the Portuguese Animal Germplasm Bank. In small ruminants, individual variations in the quality of frozen semen have been observed, suggesting specific differences in sperm susceptibility to freezing methods, particularly obvious in goat males. Best quality frozen semen from small ruminants is being used in cervical artificial insemination studies aiming to increase productive parameters in selected flocks.

High risk of infertility and long term gonadal damage in males treated with high dose cyclophosphamide for sarcoma during childhood

Abstract: BACKGROUND Therapy with alkylating agents, such as cyclophosphamide, can be associated with irreversible gonadal toxicity in male survivors of adult cancer. To the authors's knowledge the effect of high dose therapy with cyclophosphamide during childhood on adult testicular reproductive and endocrine function has not been established. METHODS Gonadal function was studied in 17 adult male survivors of childhood sarcomas treated with high dose pulse cyclophosphamide therapy as part of a VAC (vincristine, actinomycin, and cyclophosphamide) or Adria-VAC (doxorubicin, vincristine, actinomycin, and cyclophosphamide) chemotherapy regimen. Patients answered a questionnaire concerning sexual functioning and underwent a comprehensive physical examination, semen analysis, and hormonal evaluation. RESULTS Of the 17 males who underwent semen analysis, 10 (58.8%) had azoospermia, 5 (29.4%) had oligospermia, and only 2 (11.8%) were found to have a normal sperm count. All patients treated prior to the onset of puberty had an abnormal semen analysis. The 2 patients with normal sperm counts received the lowest doses of cyclophosphamide ( 3 times that of baseline in 13 of /14 patients (92.9%), suggesting some degree of Leydig cell insufficiency. CONCLUSIONS The results of the current study show a high risk of gonadal dysfunction in men exposed to cyclophosphamide during childhood as part of a VAC/Adria-VAC chemotherapy regimen. Exposure prior to puberty was not found to be protective, and the risk of infertility appeared to increase with higher doses of therapy. To the authors' knowledge the clinical significance of impaired Leydig cell function beginning at a young age is unknown and merits further study. Cancer 2001;91:613–21. © 2001 American Cancer Society.

Regional differences in semen quality in Europe

Abstract: Recent reports have indicated a decrease in semen quality of men in some countries, and suggested regional differences. A study was undertaken of semen samples from 1082 fertile men from four European cities (Copenhagen, Denmark; Paris, France; Edinburgh, Scotland; and Turku, Finland). Semen analysis was standardized, interlaboratory differences in assessment of sperm concentration were evaluated, and morphology assessment centralized. Lowest sperm concentrations and total counts were detected for Danish men, followed by French and Scottish men. Finnish men had the highest sperm counts. Men from Edinburgh had the highest proportion of motile spermatozoa, followed by men from Turku, Copenhagen and Paris. Only the differences between Paris/Edinburgh and Paris/ Turku were statistically significant (P < 0.003 and P < 0.002 respectively). No significant differences in morphology were detected. A general seasonal variation in sperm concentration (summer 70% of winter) and total sperm count (summer 72% of winter) was detected. Semen quality of a 'standardized' man (30 years old, fertile, ejaculation abstinence of 96 h) were estimated. Typically, sperm concentrations (× 10 6 /ml) for winter/summer were: Turku 132/93; Edinburgh 119/84; Paris 103/73; and Copenhagen 98/69. These differences in semen quality may indicate different environmental exposures or lifestyle changes in the four populations. However, it remains to be seen whether such changes can account for these differences. These data may also serve as a reference point for future studies on time trends in semen quality in Europe.

Diabetes Mellitus and Sperm Parameters

Abstract: Because of the paucity of studies and inconsistencies regarding the impact of diabetes mellitus (DM) on semen quality, this disease is seldom looked for in the infertile patient. Recently, this view has been challenged by findings showing that DM induces subtle molecular changes that are important for sperm quality and function. This brief review shows the main sperm parameters in patients with DM and presents the mechanisms hypothesized to explain the changes observed in these patients. The data available suggest that DM alters conventional sperm parameters. In addition, DM causes histologic damage of the epididymis, with a negative impact on sperm transit. Various mechanisms may explain the sperm damage observed in patients with DM. These include endocrine disorders, neuropathy, and increased oxidative stress. Many authors suggest that DM decreases serum testosterone levels. This is associated with a steroidogenetic defect in Leydig cells. In addition, diabetic neuropathy seems to cause atonia of seminal vesicles, bladder, and urethra. Furthermore, DM is associated with an increased oxidative stress, which damages sperm nuclear and mitochondrial DNA. Finally, spermatogenesis derangement and germ cell apoptosis in type 1 DM may relate to a local autoimmune damage, whereas insulin resistance, obesity, and other related comorbidities may impair sperm parameters and decrease testosterone serum levels in patients with type 2 DM.