MODERN VIEWS ON GASTROESOPHAGEAL REFLUX DISEASE IN CHILDREN: ISSUES OF CLASSIFICATION, ETIOLOGY AND PATHOGENESIS (PART I)

The review is devoted to modern views on the etiology, pathogenesis, clinical picture, methods of diagnosis and surgical treatment of gastroesophageal reflux disease (GERD) in children. An analysis of scientific literature by domestic and foreign authors on the evolution of molecular genetic and cytogenetic studies, the role of morphological and immunohistochemical mechanisms in diagnostics is presented, the researchers’ opinions regarding the timing and tactics of surgical intervention, as well as the advantages of minimally invasive surgery for GERD are considered.

Interstitial Telomeric-like Repeats (ITR) in Seed Plants as Assessed by Molecular Cytogenetic Techniques: A Review

The discovery of telomeric repeats in interstitial regions of plant chromosomes (ITRs) through molecular cytogenetic techniques was achieved several decades ago. However, the information is scattered and has not been critically evaluated from an evolutionary perspective. Based on the analysis of currently available data, it is shown that ITRs are widespread in major evolutionary lineages sampled. However, their presence has been detected in only 45.6% of the analysed families, 26.7% of the sampled genera, and in 23.8% of the studied species. The number of ITR sites greatly varies among congeneric species and higher taxonomic units, and range from one to 72 signals. ITR signals mostly occurs as homozygous loci in most species, however, odd numbers of ITR sites reflecting a hemizygous state have been reported in both gymnosperm and angiosperm groups. Overall, the presence of ITRs appears to be poor predictors of phylogenetic and taxonomic relatedness at most hierarchical levels. The presence of ITRs and the number of sites are not significantly associated to the number of chromosomes. The longitudinal distribution of ITR sites along the chromosome arms indicates that more than half of the ITR presences are between proximal and terminal locations (49.5%), followed by proximal (29.0%) and centromeric (21.5%) arm regions. Intraspecific variation concerning ITR site number, chromosomal locations, and the differential presence on homologous chromosome pairs has been reported in unrelated groups, even at the population level. This hypervariability and dynamism may have likely been overlooked in many lineages due to the very low sample sizes often used in cytogenetic studies.

The Cytogenetics of the Water Buffalo: A Review

The water buffalo (Bubalus bubalis), also known as the Asian buffalo, is an essential domestic bovid. Indeed, although its world population (~209 million heads) is approximately one-ninth that of cattle, the management of this species involves a larger human population than that involved with raising cattle. Compared with cattle, water buffalo have been understudied for many years, but interest in this species has been increasing, especially considering that the world population of these bovids grows every year—particularly that of the river buffalo. There are two genera of buffalo worldwide: the Syncerus (from the African continent), and the Bubalus (from the southwest Asian continent, Mediterranean area, southern America, and Australia). All species belonging to these two genera have specific chromosome numbers and shapes. Because of such features, the study of chromosomes is a fascinating biological basis for differentiating various species (and hybrids) of buffaloes and characterizing their karyotypes in evolutionary, clinical, and molecular studies. In this review, we report an update on essential cytogenetic studies in which various buffalo species were described from evolutionary, clinical, and molecular perspectives—particularly considering the river buffalo (Bubalus bubalis 2n = 50). In addition, we show new data on swamp buffalo chromosomes.

Optimization of the sperm processing protocol for subsequent molecular cytogenetic studies

One of the causes of spontaneous pregnancy termination, infertility, and birth of children with development delay and malformations are chromosomal abnormalities (CA) as well as spontaneous aneuploidies in gametes of phenotypically normal parents. Often couples with reproductive problems, as well as spouses one of whom is a carrier of CA, turn to the programs of assisted reproductive technologies (ART) for preimplantation evaluation of the zygote chromosomal status. As part of ART programs, parental gametes are examined to assess the level of spontaneous aneuploidy. As a rule, the most accessible material for analysis is the ejaculate. Fluorescent in situ hybridization (FISH) is used to examine male gametes obtained from the ejaculate. However, this FISH-analysis has a number of limitations and difficulties because of the peculiarities of the sperm head structure, namely the supercondensed state of chromosome chromatin. In order to optimize the FISH protocol, five different protocols were used for pre-hybridization processing of ejaculate samples obtained from nine phenotypically normal men. A comparative analysis of hybridization efficiency showed that the protocol using tris(2-carboxyethyl)phosphine hydrochloride (TCEP) as a decondensation agent was the most effective for subsequent molecular cytogenetic studies. The developed hybrid protocol combining proteolytic pretreatment, TCEP and thermal decondensation can be used when other protocols for pre-hybridization treatment of ejaculate preparations are not effective.

Results of external quality assessment of cytogenetic investigations for 2020

Представлены результаты экспертной оценки качества цитогенетических исследований в лабораториях РФ в системе межлабораторных сличительных испытаний «ФСВОК» за 2020 г. The results of the expert assessment of the quality of cytogenetic studies in the laboratories of the Russian Federation in the system of interlaboratory comparison tests «FSVOK» for 2020 are presented.

Breast cancer in patients after augmentation with implants

Relevance. Currently, there is no definite answer to the question of the cause of breast cancer, since it is a systemic and multifactorial disease. Given that the number of aesthetic operations on the mammary glands using endoprostheses only increases every year, new cases of detection of malignant diseases do not decrease. Some researchers are beginning to speak out about the possible connection of augmentation mammoplasty in the anamnesis with the subsequent occurrence of breast cancer due to inadequate clinical and instrumental examination and ignoring some of its components (for example, the mammographic examination). Introduction. Taking into account the analysis of the literature and the presented clinical examples, the possible reasons for the connection of augmentation mammoplasty in the anamnesis with the subsequent detection of a malignant neoplasm are analyzed. Materials and methods. We analyzed domestic and foreign literature and described two clinical examples with authentic documentation based on the results of the examination and treatment. The article describes in detail the schemes of drug treatment and descriptions of the results of morphological examination of the surgical material. The types and results of surgical treatment with reliable photos are also presented. Results. Given the complexity of the diagnostic stage in patients with breast endoprosthesis in the described clinical examples, family history collected in sufficient detail, cytogenetic studies conducted, we should talk about the likely underdiagnosis during preventive examinations. Conclusion. The multifactorial and systematic nature of such a disease as breast cancer suggests that perhaps an intensive increase in the detectability of the above-mentioned against the background of previously performed aesthetic surgery would be the simplest solution to the problem. In this category of patients, anamnesis should be collected in more detail and carefully, and the entire complex of clinical and instrumental examinations, including mammography, magnetic resonance and ultrasound examinations, should be performed in order to fully diagnose and develop further patient management tactics.

Comparative analysis of hypotonic solutions for cytogenetic studies of animals

Relevance. Cytogenetic studies are in demand to identify carriers of hereditary anomalies. In order to obtain metaphase plates of the chromosomes of various animal species, we optimized the usual method, taking into account some adjustments.Methods. The main research criterion was the selection of a hypotonic solution for cytogenetic studies in sheep and goats. 3 variants of using hypotonic solutions were considered: 0.56% solution of potassium chloride; distilled water and 0.56% solution of potassium chloride; 2% solution of sodium citrate and 0.56% solution of potassium chloride (1:1). For the cultivation of peripheral blood cells, blood was taken from the jugular vein of animals (goats n = 8, sheep n = 11).Results. The cells were cultured according to the generally accepted method. The results of the conducted studies showed that the quality of the preparations differed depending on the components used. The optimal parameters for the preparation of chromosomes with a good distribution were obtained by culturing sheep lymphocyte cells using 0.56% potassium chloride as a hypotonic solution (20 min) and ranged from 14.29 to 25.00%. For cytogenetic studies in goats, optimal results were found when using a 2% solution of sodium citrate with a 0.56% solution of potassium chloride (1:1) for 20 minutes — from 13.33 to 25.00%. Each option allowed to reduce the loss of cells during the preparation of chromosome preparations for a certain type of animal. Thus, the developed protocol for obtaining metaphase plates using a 2% solution of sodium citrate with a 0.56% solution of potassium chloride (1:1) as a hypotonic solution is optimal when used in goats, while the classical method (0.56% solution of potassium chloride) was most suitable for sheep.

MORE THAN A CENTURY OF CYTOGENETIC STUDIES IN CHILEAN PLANTS: HOW MUCH HAVE WE PROGRESSED?

An overview is provided on the cytogenetic of Chilean plants, highlighting information gathered from more than a century of work carried out by foreign and national researchers who have contributed to the study of native species. We briefly present the progress made to date and also emphasize some strategies that, in our opinion, could spur further advances in this second century of cytogenetic studies in Chilean plants. Key words: Cytogenetics, cytogenomics, Chilean plants.