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Biomedical subjects

A Popova

Publications and source records attributed to A Popova.

At least 19 recordsLinked to original sources
PubMed2005

Dynamics of storage reserve deposition during Brassica rapa L. pollen and seed development in microgravity.

Pollen and seeds share a developmental sequence characterized by intense metabolic activity during reserve deposition before drying to a cryptobiotic form. Neither pollen nor seed development has been well studied in the absence of gravity, despite the importance of these structures in supporting future long-duration manned habitation away from Earth. Using immature seeds (3-15 d postpollination) of Brassica rapa L. cv. Astroplants produced on the STS-87 flight of the space shuttle Columbia, we compared the progress of storage reserve deposition in cotyledon cells during early stages of seed development. Brassica pollen development was studied in flowers produced on plants grown entirely in microgravity on the Mir space station and fixed while on orbit. Cytochemical localization of storage reserves showed differences in starch accumulation between spaceflight and ground control plants in interior layers of the developing seed coat as early as 9 d after pollination. At this age, the embryo is in the cotyledon elongation stage, and there are numerous starch grains in the cotyledon cells in both flight and ground control seeds. In the spaceflight seeds, starch was retained after this stage, while starch grains decreased in size in the ground control seeds. Large and well-developed protein bodies were observed in cotyledon cells of ground control seeds at 15 d postpollination, but their development was delayed in the seeds produced during spaceflight. Like the developing cotyledonary tissues, cells of the anther wall and filaments from the spaceflight plants contained numerous large starch grains, while these were rarely seen in the ground controls. The tapetum remained swollen and persisted to a later developmental stage in the spaceflight plants than in the ground controls, even though most pollen grains appeared normal. These developmental markers indicate that Brassica seeds and pollen produced in microgravity were physiologically younger than those produced in 1 g. We hypothesize that microgravity limits mixing of the gaseous microenvironments inside the closed tissues and that the resulting gas composition surrounding the seeds and pollen retards their development.

Brassica↗
PubMed2004

Mesomelic form of chondrodysplasia and congenital glaucoma associated with de novo translocation (13;18)(q14;q23).

Mesomelic form of chondrodysplasia and congenital glaucoma associated with de novo translocation (13;18)(q14:q23): Mesomelic dysplasias are characterized by limb shortening most prominent of the middle segment of the extremities (forearm and lower leg). In addition to several syndromic forms a few patients with sporadic or familial forms and without precise nosological classification have been reported so far. In this report we present a young female with disproportionate mesomelic dwarfism, dysmorphic facial features, bilateral glaucoma, patent ductus arteriosus, low and hoarse voice, and generalized muscular hypotonia. At the age of 2.5 years mental development is normal. High resolution G-banded chromosome studies revealed a de novo reciprocal translocation with karyotype 46,XX t (13;18)(q14;q23). The concurrence of this de novo autosomal translocation with this distinct phenotype supports the hypothesis that disruption of (a) gene(s) at the translocation breakpoints causes this unusual, apparently new form of skeletal chondrodysplasia.

Abnormalities, Multiple↗
PubMed2003

[Is there a correlation between the vaginal colonization with group B streptococci and premature deliveries?].

The study covered 110 pregnant females during the period from January 1, 2002 till April 30, 2003. Nine females (8.18%) delivered premature newborns. Samples were taken from the posterior vaginal fornix and canalis cervicalis in the 18th and 24th gestational week. The preparations stained after Gram were examined under light microscope. Microbial cultures on blood agar were examined, too. It was established that 18 or 16.36% of all the cases presented with cultures positive for group B streptococci (Str. agalactiae) and Ureaplasma urealythicum. Some other microbial flora representatives such as Chlamydia trachomatis, Neisseria gonorrhoea and Trichomonas vaginalis were additionally identified. The independent colonization with Str. agalactiae prior to the 18th gestational week does not relate to the spontaneous abortions and premature deliveries at all. On the other hand, the colonization with Group B streptococci or their symbiosis with other microorganisms after the 23rd-24th gestational week displays a certain correlation with the premature births.

Adult↗
PubMed2002

Congenital toxoplasmosis: eye manifestations in infants and children.

The eye manifestations of congenital toxoplasmosis were investigated in 38 infants and children. Diagnosis of the congenital ocular lesions was established clinically, using also X-ray, computed tomography and ultrasonography, and confirmed by two immunodiagnostic techniques. Infants and children were examined when one or more characteristic manifestations of ophthalmic disorders were present. Typical symptoms and signs can present at birth or appear later in life. The multiplicity of clinical manifestations is characteristic of the disease. The most common symptom was chorioretinitis (92%), associated in 71% of the cases with other ocular lesions, and the second most common symptom was microphthalmia and strabismus. The inflammatory process also involved the anterior segment of the eye: iridocyclitis, cataract, glaucoma. Other rare findings were hydrocephalus, calcification in the brain, paresis, epilepsy and diminished visual acuity. The study showed that transplacental transmission of Toxoplasma to the fetus can have severe clinical consequences and terminate in fatal ocular impairment.

Adolescent↗
PubMed2002

[Association between Mycoplasma genitalium and preterm labor].

M. genitalium was identified by using polymerase chain reaction (PCR). The samples were obtained from the posterior vaginal fornix between 21-25 gestation weeks and investigated for PH, Gram Stain for bacterial vaginosis; Chlamidia trachomartis; Neisseria gonorrhoeae; Trichomonas vaginalis. Of 102 pregnant women, only five had a PCR-positive for M. genitalium. The occurrence of M. genitalium in posterior vaginal fornix at midtrimester is infrequent in pregnant women and unlikely to be a contributing factor for spontaneous preterm birth.

Animals↗
PubMed2002

Reserve nutrient substance accumulation in Brassica rapa L. seeds in microgravity conditions (STS-87).

The results of study of Brassica embryo differentiation and reserve nutrient substance accumulation in the seeds were represented. Near resemblance of the spaceflight and around control embryo development was revealed. Different character of the reserve substance accumulation was noted, despite of the morphologic similarity in seeds produced in spaceflight and on the ground. It allows to consider spaceflight embryos morphologically more younger compared to the ground control.

NASA Discipline Plant Biology↗
PubMed2000

Pollination and embryo development in Brassica rapa L. in microgravity.

Plant reproduction under spaceflight conditions has been problematic in the past. In order to determine what aspect of reproductive development is affected by microgravity, we studied pollination and embryo development in Brassica rapa L. during 16 d in microgravity on the space shuttle (STS-87). Brassica is self-incompatible and requires mechanical transfer of pollen. Short-duration access to microgravity during parabolic flights on the KC-135A aircraft was used initially to confirm that equal numbers of pollen grains could be collected and transferred in the absence of gravity. Brassica was grown in the Plant Growth Facility flight hardware as follows. Three chambers each contained six plants that were 13 d old at launch. As these plants flowered, thin colored tape was used to indicate the date of hand pollination, resulting in silique populations aged 8-15 d postpollination at the end of the 16-d mission. The remaining three chambers contained dry seeds that germinated on orbit to produce 14-d-old plants just beginning to flower at the time of landing. Pollen produced by these plants had comparable viability (93%) with that produced in the 2-d-delayed ground control. Matched-age siliques yielded embryos of equivalent developmental stage in the spaceflight and ground control treatments. Carbohydrate and protein storage reserves in the embryos, assessed by cytochemical localization, were also comparable. In the spaceflight material, growth and development by embryos rescued from siliques 15 d after pollination lagged behind the ground controls by 12 d; however, in the subsequent generation, no differences between the two treatments were found. The results demonstrate that while no stage of reproductive development in Brassica is absolutely dependent upon gravity, lower embryo quality may result following development in microgravity.

Brassica↗
PubMed1994

Locomotor rating of young men investigated in a clinical kinesiologic screening.

Diminished capacity for physical activity results from the reduction of the locomotor activity of our population, and young people in particular. On the basis of a mass screening study of their clinico-kinesiologic status using an author's method, functional assessment of this status was made employing an author's own constellation, and the term locomotor insufficiency was put forward. In the present article 469 young people aged 17-26 were rated according to the results of the study of 57 objective and subjective clinico-kinesiologic parameters summarized in indices used in the assessment of the locomotor insufficiency. The study revealed a disturbing tendency towards deterioration of the general clinico-kinesiologic condition and muscle imbalance in the investigated young people. Some of categories, such as profession, level of disability, or engagement in sports, demonstrated relation to the parameters which make up the system for assessment of the locomotor insufficiency linked globally and segmentarily with the other systems of the body.

Adolescent↗
PubMed1990

[Fetal shoulder girdle dystocia during labor].

Shoulder dystocia occurred in 98 women (0.9%) among 10,695 deliveries during the period of 1986-1988. The most frequent cause was overweight and strangulated umbilical cord. The following maneuvers were used: pressure on the uterine fundus, strong flexion of legs (maneuver of Knebel-Macroberts-Korokawa) and in 12 cases--extraction of the posterior hand. The head should be rotated to the opposite thigh of the parturient in cases with incorrect rotation of the head--the most frequent cause for low shoulder dystocia. Prophylactic measures are of special significance: cesarean section in women with large fetus, estimated by ultrasound, or with fetus with thoracic diameter larger than biparietal diameter with 1.5 sm. The delivery should be managed by the most experienced obstetricians and should not be protracted or precipitate without indications.

Adult↗