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Biomedical subjects

V Markova

Publications and source records attributed to V Markova.

At least 19 recordsLinked to original sources
PubMed2000

[The basic problems and outlook for assisted reproductive technologies].

In this article the authors discuss some problems in ART:COH, stimulation protocols, culture media, transfer of embryos, luteal phase support, ethical, financial, religious and legal problems etc. Tha main complications are discussed, toosyndrom and pseudosyndrom of the empty follicle, OHSS, multiple pregnancy. In these cases the prophylactic and therapeutical measures are pointed out. Finally the main perspectives and developments of ART in the new millennium are outlined.

Ethics, Medical↗
PubMed1998

Rearrangement of T-cell receptor and immunoglobulin heavy chain genes in leukemia and lymphoma.

The development of polymerase chain reaction /PCR/ has greatly facilitated the detailed characterization of T-cell receptor /TcR/ and immunoglobulin heavy chain /IgH/ gene rearrangements. The antigen-receptor genes in lymphoid cells undergo rearrangements by combination of variable /V/, diversity /D/ and joining /J/ gene segments, deletion of germline nucleotides and insertion of nontemplate-derived nucleotides /"N-regions"/. In this preliminary study we analysed 12 DNA samples from patients with lymphoproliferative disorders /LPD/ and with acute nonlymphoblastic leukemias /ANLL/. PCR analyses were performed using V and J consensus primers for conserved regions of TcRg and IgH genes. PCR products were evaluated by polyacrilamide gel electrophoresis and denaturing gradient gel electrophoresis. Applying this method, we have detected 3 TcRg and 4 IgH monoclonal rearrangements in all 12 LPD samples. One ANLL sample showed monoclonal rearrangement for TcRg. Because of the clonal rearrangements, the analysis of TcR and IgH gene configuration can be used to track the persistence of malignant cells which are determined at diagnosis. The positive results from ANLL samples will be further evaluated as prognostic criteria.

Base Sequence↗
PubMed1998

LDL-receptor gene polymorphism in patients with early-onset coronary artery disease.

Simultaneous amplification of the promoter and 17 (out of 18) exons of the LDL-R gene (along with flanking intron sequences) was performed in 36 patients with hypercholesterolemia and early-onset coronary artery disease. The identification of the PCR-products on denaturing gradient gel electrophoresis (DGGE) revealed 34 cases of heteroduplexes in 24 patients. The heteroduplexes in exons 12, 10, and 2 (31%, 28% and 22%, respectively) probably reflect common polymorphism of LDL-R gene, while heteroduplexes in exons 6, 4 and 13 are less frequent (5.6%, 5.6%, and 2.8%, respectively). Significant association between the genetic variants, or polymorphism with clinical manifestations, could not be established.

Adult↗
PubMed1998

A case of Friedreich's ataxia confirmed by DNA-analysis.

The first case of DNA-confirmed Friedreich's ataxia in Bulgaria is presented. The results from the DNA studies of the index patient revealed two alleles with an expansion between 500 and 1500 repeats of the GAA trinucleotide in the first intron of the X25 gene. The parents had one normal allele with 7-22 repeats and one allele with a similar expansion to that of the patient in the first intron of the X25 gene. These results confirm the homozygous mode of transmission of the abnormal alleles (with an expansion of the GAA trinucleotide in the first intron of the X25 gene) from the two normal heterozygous parents to their affected offspring.

Adolescent↗
PubMed1998

Quantitative analysis of the expression of apoptosis-related genes.

BACKGROUND: The development and subsequent introduction of current molecular biology techniques allows the elucidation of some of the mechanisms of the programmed cell death (apoptosis). The overexpression of the genes directly (B-cell leukemia/lymphoma-2, BCL-2) or indirectly (multidrug resistance gene-1, MDR1) involved in the suppression of apoptosis, as well as the low-level expression of their antagonists (BCL-2 associated X-protein, BAX) result in longer survival and the development of drug resistance in malignant cells. AIM: The objective of this study was to design our own appropriate primers and to synthesize internal RNA standards and this way to evaluate the rate of expression of the MDR1, BCL-2 and BAX genes using a competitive reverse transcription and polymerase chain reaction (cRT-PCR). MATERIAL AND METHODS: Peripheral blood or bone marrow aspirates from 5 patients and 3 healthy controls were used for RNA extraction. Competitive RT-PCR was employed utilizing the constructed specific primers and synthesized internal RNA standards. Following electrophoresis, the PCR products stained with ethidium bromide were evaluated on the "Gel Doc 1000TM" video image system. RESULTS: The constructed primers specific for each of the three genes and synthesized internal RNA standards with a suitable deletion allow receiving the yield of well-separated competitive amplicons. The measured band's intensity of light and the calculated standard/patient ratio were employed in the analysis of the MDR1, BCL-2 and BAX gene expression. CONCLUSIONS: Competitive RT-PCR is a non-radioactive and comparatively rapid molecular biology method suitable for everyday laboratory practice. The possibility for simultaneous evaluation of the expression of several genes could help in the elucidation of some of the mechanisms underlying the prolonged survival of malignant cells.

Apoptosis↗
PubMed1997

Evaluation of an ion-selective electrolyte analyzer: Microlyte 6.

Microlyte 6 (Kone, Finland) is an ion-selective analyzer designed to measure simultaneously the concentration of six important electrolyte parameters--potassium, sodium, chloride, ionized calcium, ionized magnesium and pH in whole blood, serum and plasma. Two values are obtained in analyzing the ionized fractions of magnesium and calcium--one at the actual pH and another at a recalculated measurement for pH = 7.4. Direct determination of ionized calcium and ionized magnesium simultaneously with that of the other electrolytes is of great clinical significance. It is only recently that ion-selective analysis of ionized magnesium has been proposed. The analytical reliability of the results and the operational characteristics of the Microlyte 6 ion-selective analyzer were evaluated for approximately one year. The coefficient of variation of the results in the reference and pathological range was 0.49%-2.23%, and 0.68%-4.42% for the within-run and between-run series, respectively. The inaccuracy of the results expressed by d% was from -4.23% to +4.06%. The comparative evaluation of the results for potassium, sodium, chloride, and ionized calcium between Microlyte-6 and the clinical chemistry analyzer Dynamic (Kone) showed a high correlation (correlation coefficient in the range 0.9868-0.9970). The correlation between the results for the ionized fraction and those obtained for total magnesium was consistent with that generally given in the literature.

Chemistry, Clinical↗
PubMed1994

[Endometriosis in clinical practice].

The authors are investigated the frequency of the cases of genital endometriosis, its most frequent localization and the choice of treatment on 864 women patients who have undergone operations connected with other gynaecological disorders and on 32 women patients, suffering sterility and proved endometriosis. Most frequent are the cases of combination between uterine myoma and endometriosis of the uterine wall-5.74% and with the patients who have undergone surgery for malignant disease between endometrium carcinoma and uterine endometriosis. The conservative treatment is the method of choice with the infertile women suffering a slight stage of endometriosis and the least conservative method is the surgical treatment, followed by a hormonal treatment resulting in the increase of the fertility of women who have the average stage of development of endometriosis.

Adult↗
PubMed1992

Studies on the plasma cholesterol and triacylglycerols in chronic methemoglobinemia in rats.

Plasma cholesterol and triacylglycerols were measured in rats with modelled chronic two-stage (mild and moderate) intermittent nitrite methemoglobinemia for 15 and 30 days. It was found that at the moment of methemoglobinemic peak (60 +/- 10 min) the experimental animals had mixed (hemtoxic, anemic and hypoxic) hypoxemia. The every day "pulse" decrease of the total oxygen concentration during the 30-day methemoglobinemia was accompanied with a significant rise (p < 0.05) of cholesterol concentrations in the high-density lipoproteins and the total cholesterol, as well as a decrease in the amount of triacylglycerols. These changes are considered to represent the side effects of adaptation for whose elucidation further research is needed.

Animals↗
PubMed1989

[The course of pregnancy and labor following artificial insemination].

The course of pregnancy and its final outcome--delivery of alive and viable fetus, is of special significance for women becoming pregnant after artificial insemination because of their limited possibilities for new pregnancy. 131 pregnancies, occurring after artificial insemination with fresh and frozen seminal plasma, were investigated. Analysis of the results showed that in basic lines the course of pregnancy and delivery as well as the state of the newborns did not differ substantially from those of normally conceived women. There was no statistical difference (p greater than 0.05) in the frequency of still-births, preterm deliveries and congenital anomalies of the fetus. In the course of pregnancy of women with artificial insemination two risk periods are determined. a) first trimester because of the greater frequency of spontaneous abortions b) delivery because of the increased operative activity and greater frequency of multiple pregnancy.

Abortion, Spontaneous↗
PubMed1989

[Male infertility as a cause of familial sterility (based on data from the Office of Sterility Prevention--the District Hospital Polyclinic and Higher Medical Institute--in the city of Varna)].

The fight against sterility in the family is of great psychosocial significance. Male infertility has not a small part of the causes for sterile marriage. 1470 sterile married couples were recorded in the dispensary system of the consulting room for the fight against sterility in the family at the district hospital in the town of Varna during the period of 1975-1986. Seminological examinations of the husband were performed three times and the final seminological diagnosis was established. The performed examinations showed clearly that almost 1/3 of men had seminological disturbances. The male infertility in sterile married couples increased on the average with 10.28% per year during the investigated period as for men with oligospermia this increase was higher (12.08%) in comparison with azoospermia (6.56%). Prognosis for advancement of disturbances in spermatogenesis was made on the basis of the collected information. The results showed a tendency to a general increase of the frequency of male infertility during the following years. An inference is made that it is necessary to improve work connected with prophylaxis, early discovery and treatment of diseases, which cause male infertility.

Bulgaria↗
PubMed1987

High-resolution chromosome analysis in retinoblastoma.

Peripheral blood chromosomes of 13 patients with retinoblastoma and of their 20 first degree relatives were examined. In three of them chromosomal aberrations were found. Chromosomal anomalies were revealed in one case the patient's father only (the child died and the examination could not be performed) [del(13)(q12.11-q12.13)] and in another case both in the patient [t(13;14)] and in the father as well. This data support the view that some cases of retinoblastoma are closely linked to chromosomal rearrangements in the parental karyotype.

Child↗