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Biomedical subjects

L I Vorob'eva

Publications and source records attributed to L I Vorob'eva.

At least 19 recordsLinked to original sources
PubMed2005

[Inheritance features of mating behavior components in Drosophila melanogaster and their significance for fitness].

Components of mating behavior of Drosophila melanogaster mutant and wild-type strains were studied with respect to fitness. The magnitude of the effect of genotype on the male mating activity, female sexual receptivity, fertility and viability was determined. Strong positive correlation was found between the male mating activity and fitness components. It was shown that mating of strains contrasting in sexual behavior features can be accompanied by both heterosis and maternal effect. Inheritance coefficients were determined for sexual behavior components.

Animals↗
PubMed2003

[Influence of genotype on endoreduplication of giant chromosomes and expressivity of character eyeless in Drosophila melanogaster].

In Drosophila melanogaster lines LA (low activity), HA (high activity), and Oregon-R (wild type), the effect of genetic background on endoreplication in giant chromosomes of salivary glands, fecundity, and expression of mutation ey was studied. The degree of chromosome polyteny and the number of adult flies in saturated lines eyHA, eyBA, and eyOr were significantly higher than in the original lines. The degree of chromosome polyteny was correlated with fecundity. The expressivity of the ey character was shown to be far lower in lines eyLA, eyHA, and eyOr than in the original eyeless line. In the saturated lines, the eye facets were reduced to a similar degree. All the lines studied displayed clear-cut sexual distinctions in this parameter. In the eyHA line, the coefficients of variation for the degree of chromosome polyteny, fecundity, and expressivity of the ey mutation were much lower than in lines eyeless, eyLA, and eyOr.

Animals↗
PubMed2002

[The effect of the genotype on the expressiveness of the vestigial trait and polyteny of chromosomes in Drosophila melanogaster Meig].

The effects of the Bar (B) and white (w) mutations on the expressiveness of the character vestigial (vg) and the degree of polyteny of salivary gland giant chromosomes were studied in Drosophila melanogaster. Either mutation changed both the expressiveness of vestigial and the degree of chromsome polyteny. A negative association between the vg expressiveness and the degree of chromosome polyteny was revealed and proved to be stronger in females than in males. The parameters under study were shown to differ between females and males.

Animals↗
PubMed1999

[Effect of culture density and degree of expression of the trait "eyeless" and degree of polyteny of giant chromosomes in Drosophila melanogaster].

Effects of culture density on expressivity of character eyeless and polyteny of giant chromosomes were studied in Drosophila melanogaster. Larval crowding was shown to significantly reduce eye facets. The expression of eyeless was sex-dependent: in females, this character was expressed more strongly than in males. Larval crowding resulted in a decrease of chromosome polyteny in larval salivary glands. A strong negative correlation was established between the expressivity of eyeless and the degree of giant chromosome polyteny.

Animals↗
PubMed1998

[Disorders of hormonal homeostasis in patients with kraurosis and leukoplakia vulvae].

A study was made into the functional status of hypophysis, adrenal cortex, ovaries, and thyroid gland in patients with kraurosis and leukoplakia vulvae. The above patients demonstrated profound disturbances in the system hypophysis-ovaries, that attest to the need for applying corrective therapies to treat the disturbed hormonal homeostasis.

Aged↗
PubMed1995

[Antimutagenic action of bacterial culture liquid on mutagenesis induced by 2-nitrofluorene in Salmonella typhimurium strains].

It was shown that cell extracts and cells of Streptococcus faecalis decrease the mutagenic effect of 2-nitrofluorene in Salmonella typhimurium strain TA1538 by 73 and 48%, respectively. Cell extracts and cells of Bifidobacterium bifidum and Propionibacterium shermanii exhibited weak antimutagenic activity. No antimutagenic effect was found in Escherichia coli AB1157, Lactobacillus delbrueckii, or Streptococcus thermophilus. Antimutageneicity of the cell extract of Str. faecalis is both associated with extracellular factors interacting with 2-nitrofluorene (desmutagenesis) and with factors affecting intracellular processes of mutagen biotransformation and mutation induction. Thiol compounds produced by growing Str. faecalis may be desmutagenic factors. A relatively heat-stable substance or substances of a peptide nature with a MM less than 12 kDa are antimutagenic factors affecting intracellular processes of mutagenesis.

Antimutagenic Agents↗
PubMed1993

[Antimutagenic action of superoxide dismutase on sodium azide- and nitrosoguanidine-induced mutagenesis in Salmonella typhimurium TA 1535].

It was shown that superoxide dismutase (SOD) decreased the mutagenic action of sodium azide (NaN3) and N-methyl-N'-nitro-N-nitrosoguanidine in Salmonella typhimurium TA1535. Catalase and quenchers of hydroxyl radicals showed, unlike SOD no effect on the mutagenicity of NaN3. Cell extract from propionic acid bacteria also possessed the antimutagenic activity, only partially depending on the SOD activity.

Antimutagenic Agents↗
PubMed1992

[The endocrinological aspects of cancer of the vulva].

Patients with cancer of the vulva showed significant disorders of pituitary adrenal cortex, ovarian and thyroid function. This requires carrying out corrective hormone therapy with the purpose of increasing the efficiency of combined treatment.

Adrenal Cortex↗
PubMed1990

[Recurrent endometrial cancer after combined radiation therapy].

Data of a patients are reported who developed recurrence of highly differentiated cancer of the endometrium 20 years after combined. At that time the patient harboured also a borderline mucinous cystadenoma of the ovary with malignization foci. An analysis of the lymphocyte karyotype in the peripheral blood revealed a 14% increase of aberrant cells.

Adenocarcinoma↗
PubMed1990

[Use of genetic analysis methods in examining patients with endometrial cancer].

An analysis of clinical and family history of 36 patients with endometrial cancer revealed clustering of tumors in some families. Cytogenetic studies of peripheral lymphocytes showed increased counts of aberrant cells in patients with endometrial cancer as against their values in normal women and patients with endometrial hyperplasia.

Adult↗
PubMed1987

[Search for propionic acid bacteria in the human intestine].

The possibility of detecting propionic acid-producing bacteria in the intestine of healthy humans with a view to obtaining a strain which is physiologically most suitable for therapeutic purposes has been studied. The selective conditions for the isolation of propionic acid-producing bacteria from the large intestine have been experimentally established. Analysis of 70 puncture biopsy specimens of parietal mucus and luminal contents from different sections of the intestine has not shown the presence of the representatives of propionic acid-producing bacteria. The strains isolated under the conditions selective for such bacteria have been found to belong to the family Enterobacteriaceae. These strains have proved capable of synthesizing vitamin B12, but the synthesis of propionic acid has not been observed.

Adult↗
PubMed1987

[Effect of cobalamin derivatives on DNA synthesis in cells of Propionibacterium freudenreichii subsp. shermanii].

The increase of DNA-synthesis rate (according incorporation [8-14C]adenine) in B12-deficient cells Propionibacterium shermanii as a result of different cobalamines adding into the cell suspension including metoxyethyladenile analog of adenozilcobalamin and some components of vitamin B12 molecule has been found. The DNA-synthesis rate in B12-deficient cells is nearly twice lower as compared with one in B12-normal cells. Considerable stimulative effect (80-100%) was provided with coenzyme forms of cobalamin. The data confirm the participation of vitamin B12 in DNA-synthesis in Propionibacterium cells.

DNA, Bacterial↗
PubMed1984

[Status and developmental prospects of microbiology].

The achievements of microbiology in the field of chemistry studying, molecular biology and cellular structure of bacteria are reflected in this review. The peculiarities of energetic, synthetic processes in prokaryotes and also the different methods of regulation of their metabolism have been shown. The achievements in the field of new strains construction and creation of biocatalysts on the basis of immobilized cells and enzymes for the biotechnological purposes have been elucidated. The role of microbiology in solving such social problems as the purification of environment from pollution, replenishing the resources of energy and protein which are rapidly exhausted has been shown.

Archaea↗
PubMed1982

[Polyphosphate and ATP content of Propionibacterium shermanii cells in nitrogen starvation].

When Propionibacterium shermanii was cultivated in a medium with glucose under the conditions of nitrogen deficiency, the content of high molecular weight polyphosphates (salt-soluble fraction, alkali-soluble fraction, and fraction extracted with hot perchloric acid) decreased. In contrast, it rose in a medium with lactate within two and three days of starvation. The culture growth stopped after a day under these conditions, the energy substrate was assimilated during the entire process of starvation, and the content of ATP continuously decreased. When ammonium sulfate was added after two and three days of starvation, the intracellular content of polyphosphates (in all of the three fractions) increased in the medium with glucose. If ammonium sulfate was added after three days of starvation in the medium with lactate, the content of polyphosphates rose in the fraction extracted with hot perchloric acid while the content of salt-soluble and alkali-soluble polyphosphates decreased. The culture started to grow again and the content of ATP in its cells rose abruptly when ammonium sulfate was added under these conditions. If the culture was grown in the medium with glucose and ammonium sulfate, the content of acid-insoluble polyphosphates increased twofold during the first day and dropped to the initial level by the third day of growth.

Adenosine Triphosphate↗