Trends in the formation of the ovarian follicular reserve

This review describes folliculogenesis from the formation of a primordial follicle around the oocyte during the diplotene stage of prophase of meiosis I to that of a preovulatory follicle, maturation of an oocyte, and transformation of its chromosomal nucleolus complex into the karyosphere. It briefly highlights literature disagreements on the terminology of ovarian follicular reserve and folliculogenesis. The possibilities of evaluating the ovarian follicular system are given

Impact of asymptomatic urogenital tract infections on ejaculate parameters in infertile men with varicocele

Varicocele, a pathology developing in 15 % males, is associated with 30 % male infertility cases. The role of urogenital infections coinciding with varicocele in infertile men has not been studied in sufficient detail.Objective: to examine the effects of bacterial and viral infections on ejaculate parameters in infertile patients with varicocele. The study included 49 patients with infertility and varicocele and 26 healthy males undergoing prophylactic medical examination. Highlevel infection was recorded after examination of ejaculates and urethral scrapes of 49 patients: bacterial (30.6 %) and viral (14.3 %) pathogens. Quantitative analysis of viral DNA showed high contamination of ejaculates with herpes viruses (> 3 lg10/ml). Detailed analysis of spermatograms demonstrated a decrease in all basic parameters in patients with varicocele and infertility compared with those in healthy subjects. The presence of infectious agents had a statistically significant negative effect on ejaculate parameters. Spermiological examination revealed high level of sperm abnormalities (astenozoospermia, oligoteratozoospermia, and oligoastenoteratozoospermia) in patients with infertility, varicocele and bacterioviral infection of urogenital tract compared with uninfected infertile patients with varicocele. Laboratory tests for bacterial and viral infections should be recommended in infertility associated with varicocele even in the absence of clinical signs of these infections. Quantitative analysis of urogenital pathogens allows one to determine the necessity of etiotherapy of hidden infection and to monitor the effectiveness of treatment

Genetic and epigenetic mechanisms of regulation, chronology and dynamics of spermatogenesis of mammals

Genetic and epigenetic mechanisms of spermatogenesis – long process with many stages regulation are discussed. DNA code is the entirety of hereditary information, epigenetic mechanisms of gene regulation act without altering primary nucleotide sequences. Epigenetic regulation is a complex process, in which components of different groups of epigenetic modifications (non-coding RNAs, DNA methylation and histone modification) work together. Mistakes in any of the components of the process may cause impaired spermatogenesis and/or infertility, and may cause epigenetic diseases. Nowadays 90 imprinted genes and loci on 13 chromosomes are revealed. More then 10 human diseases involving genomic imprinting are known (Angelman syndrome, Prader–Willi syndrome, Russell–Silver syndrome, Beckwith–Wiedemann syndrome etc.). DNA methylation is essential for normal development and is associated with a number of key processes including animal growth and development, transcription, DNA replication and reparation, cell differentiation, genomic imprinting, X-chromosome inactivation, suppression of repetitive elements and carcinogenesis. </p

Assisted reproductive technologies and legal aspects of sex selection

The paper covers the legal and ethical aspects of sex selection, and the dynamics of public opinion on this issue in different countries and regions of the world. Also, the results of two questionnaires, organized by Research Centre for Medical Genetics (2000 and 2017), are analyzed

Biosafety samples (sperm, oocytes and embryos person) during prolonged storage in liquid nitrogen

Cryopreservation of sperm, oocyte and embryo plays an important role in modern assisted reproductive technologies. To date the only available source of low temperatures satisfying the conditions of long-term storage of cells is liquid nitrogen. However there is a possibility of transmission of infectious agents between samples in liquid nitrogen at their co-location in a cryostorage. The article discusses ways to reduce the risk of cross-contamination and the integrated approach to biosecurity.</em

Ethical and legal issues of anonymous sperm donation

The paper covers legal and ethical aspects of the sperm donor anonymity, and the dynamics of public opinion on the anonymity of germ cells donation according to the results of the survey conducted  in1994 and 2017 by the Laboratory of Genetics of Reproductive  Disorders at the Research Centre of Medical Genetics

Ultrastructural investigation of human sperm from asthenozoospermic men

Ultrastructure of the flagellum is highly conserved and is composed of a number of cytoskeletal elements whose proper assembly is critical for sperm motility. Ultrastructural mechanisms damage as cause of asthenozoospermia development are discussed.</em

Varicocele as one of the causes of the decreased male infertility

Varicocele is one of the most common diseases of the male reproductive system. Despite the high prevalence of this pathology, the effect of varicocele on male fertility is still a controversial issue. Opinions of experts about the possible effects of varicocele on the male reproductive health, the causes and methods of treatment are contradictory, and the experimental data obtained often show directly opposed results. This article presents a review of the literature on the effects of varicocele on the male reproductive system and fertility

Genetically determined patozoospermia. Literature review and research results

Genetic factors (chromosomal aberrations and point mutations) are the cause of infertility in 10–15 % of men with impaired fertility. Homogeneous structural and functional defects in the sperm or the total terato-, asthenozoospermia – rare cases of genetically determined male infertility, are autosomal recessive diseases. Currently, described 4 types of «syndromic» spermopatology. 1. Primary ciliary dyskinesia (PCD) in men with total asthenozoospermia. Affects axoneme structures (microtubules, dynein arms, radial spokes). It identified more than 20 chromosomal loci responsible for the development of the PCD. 2. Dysplasia of the fibrous sheath of sperm tail in men with asthenozoospermia. The shortened and thickened sperm tail observed with disorganization of vertical columns and cross ribs of the fibrous sheath. Candidate genes – genes family ACAP. 3. Globozoospermia in men with teratozoospermia characterized by the presence of sperm with round heads, primary lack of acrosome and disorganization middle part of the flagellum. Found mutations or deletions of genes SPATA16, PICK1 and DPY19L2. 4. Syndrome decapitated spermatozoa in men with teratozoospermia (microcephaly). Abnormalities in the spermiogenesis development of connecting part jf the tail and proximal (morphologically normal) centrioles.In 2012–2014 years we have studied the ultrastructure of 2267 semen samples of men with impaired fertility. Globozoospermia revealed in 7 patients, dysplasia of the fibrous sheath – 13, decapitated sperm – in one. PCD was revealed in 4 patients (lack of axoneme dynein arms was found in 1 patient, absence of axoneme radial spokes – in 3 patients.The problem of genetically determined patozoospermya must be taken into account when the assisted reproductive technologies practises. There are few cases of successful assisted reproductive technologies with sperm of these patients. We don»t know the etiological factors of syndromic spermopatologe, so we cannot determine the degree of genetic risk

Structural and functional testicular anomalies in male rats exposed to acute immobilization stress

In experiments performed in infertile white male rats we found out that single session of acute immobilization stress leads to spermatogenesis anomalies continues to persist to the end of the experiment (14 days). Basic alterations were reduction of spermatogenesis index, increased membrane permeability of seminiferous tubules, development of a local hypostasis, Sertoli cells organells destruction, intracellular regeneration processes were revealed in Sertoli cells and in seminiferous tubules, however recovery of spermatogenesis in investigated period didn’t occur.</em