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Biomedical subjects

J Kanka

Publications and source records attributed to J Kanka.

At least 55 records · Page 3Linked to original sources
PubMed1989

Genome reactivation in developing early pig embryos: an ultrastructural and autoradiographic analysis.

The onset of RNA synthesis in developing early pig embryos from 1-cell to 8-cell and morula stages was studied using high-resolution autoradiography of (5-3H)uridine incorporation. No transcriptional activity was detected in nuclei of 1- and 2-cell stage embryos with this technique. In these embryos nucleolus-like bodies (NLB) consist of sharply delineated, round, electron dense fibrillar masses. In the 4-cell stage embryos, the first uridine-3H incorporation in the nucleoplasm was detected and localized mainly near the regions of condensed chromatin. The first signs of reticulation and chromatin association were observed at the periphery of NLBs. In the next cell cycle (5- to 8-cell embryos) uridine-3H labelling was detected in the nucleoplasm and nucleoli. In these embryos, nucleoli consist of a central dense fibrillar mass without any transcriptional activity and fibrillo-granular cortex over which label was localized. The degree of functional restructure of nucleoli was variable within one blastomere or among different blastomeres, some nucleoli being more reticulated and showing more transcriptional activity than others. Fully developed nucleoli were present in early morulae. Electron dense unidentified structures described here as small dense round-shaped bodies (RDB) often surrounded by blocks of large chromatin granules were observed in intact 2-cell and alpha-amanitin treated 4-cell stage embryos. These structures did not show any transcriptional activity.

Animals↗
PubMed1989

The application of plasma tartrate-resistant acid phosphatase to assess changes in bone resorption in response to artificial menopause and its treatment with estrogen or norethisterone.

Plasma tartrate-resistant acid phosphatase (TR ACP), urinary hydroxyproline excretion (UH), serum osteocalcin, and bone alkaline phosphatase isozyme were determined in a prospective study in 31 women who had undergone bilateral ovariectomy (OOX). Nine patients were followed up for 1 year without treatment and for the following 3 years when on mestranol (M) substitution. On the basis of UH, 22 patients were identified as having increased bone resorption (BR) within 3 months of OOX. Subsequently, 11 patients were treated with transdermal estradiol (E2) and 11 patients with norethisterone (norethindrone, NE). In untreated patients, the biochemical indices of BR peaked 3-6 months following OOX and biochemical indices of bone formation (BF) continued to increase from 3 until 12 months. The substitution with both E2 or M resulted in normalization in serum and urinary calcium, serum phosphate, renal threshold phosphate concentration (TmPO4/GRF), and biochemical indices of BR within 4 months of treatment. Biochemical indices of BF normalized within 6 months of treatment. In the M-treated group, these effects continued for 3 years of the follow-up. The hormonal substitution had a protective effect on cortical and lumbar spine bone mass. A significant decrease, but not to normal values, in biochemical indices of BR and a persistent elevation in indices of BF were found in NE-treated patients. Unlike E2, NE does not depress osteoblastic function. There is strong evidence supporting the utility of measurements of TR ACP in plasma in examination of women who had ovariectomies and in assessement of the efficacy of treatment.

Acid Phosphatase↗
PubMed1989

In vitro techniques of bovine oocyte maturation, fertilization and embryo culture resulting in the birth of a calf.

Oocyte cumulus complexes were aspirated from 3 to 5 mm follicles of cows prestimulated with 2.000 IU PMSG 24 h before slaughter. Oocytes matured in culture were fertilized in vitro by heparinized freshly ejaculated or epididymal spermatozoa. The cultivation procedure for fertilized eggs was the same as that used for cultivation of oocytes. From 163 matured oocytes, 109 cleaved to the 2-cell stage 24 h after fertilization and after 6 days of cultivation, 18 developed to the late morula and 18 to the blastocyst stages. Eleven blastocyts and 1 late morula were transferred surgically to the uteri of 7 recipient heifers. Two heifers became pregnant: one delivered a bull-calf at term, while the other pregnancy resulted in abortion at the 3rd month. The examination of some embryos by transmission electron microscopy showed an almost normal morphology for most cells. The degenerated cells contained mostly electron-dense residual bodies of unknown origin.

Animals↗
PubMed1989

[Transdermal estradiol in the prevention of the menopause-induced increase in osteoresorption].

In the introduction of the paper the authors explain that it is essential to adopt effective preventive provisions to prevent the loss of osseous tissue in women after the menopause and to prevent osteoporotic fractures. In Bohemia and Moravia during the last 20 years the incidence of these frequently fatal or invalidating fractures of the proximal femur has increased substantially and in view of the ageing of the population it may be assumed that this trend will proceed further. Among possible preventive provisions, in order to eliminate undesirable metabolic side-effects of long-term hormonal substitution treatment, it seems best to administer by the parenteral route natural oestradiol by using the transdermal therapeutic Estraderm TTS system. Its effectiveness in suppressing menopause-induced enhanced bone resorption was tested in 11 women where on average within three months after bilateral ovariectomy increased bone resorption was found. In all women in the course of four months treatment all biochemical indicators of bone remodelling became normal - urinary excretion of hydroxyproline, acid plasma phosphatase activity, serum alkaline phosphatase isoenzyme, and serum osteocalcin. The dynamics of indicators of osteoresorption were similar as in women treated with oral synthetic oestrogen, which may produce, however, serious metabolic side-effects. Substitution treatment with Estraderm improves significantly also other manifestations of the climacteric oestrogen deficiency syndrome. Its safety is further enhanced by combination with progesterone.

Administration, Cutaneous↗
PubMed1986

Prospective study on the relationship between cervical neoplasia and herpes simplex type 2 virus. III. Presence of herpes simplex type-2 antibody in sera of subjects who developed cervical neoplasia later in the study.

Paired sera taken from 63 subjects who developed cervical neoplasia in the course of a prospective study on this disease were examined for the presence of herpes simplex virus type 2 (HSV-2) antibody. The first serum was taken at enrollment into the study, while the second was obtained after development of the disease, i.e. 2-4 years later. Simultaneously, paired sera from a group of control subjects, who remained free of any cytological and colposcopical abnormalities throughout the study, were also investigated. Controls were matched with patients by age, age at first intercourse, number of sexual partners, smoking habits and history of diathermoelectrocoagulation of ectopic epithelium and transformation zone of the cervix. The first sera from these subjects were obtained at enrollment while the second ones were taken at the end of the study, i.e. 5 to 7 years later. Antibody titres were remarkably stable in both patients and control subjects. Seroconversions from HSV-2 negativity to HSV-2 positivity as measured by the increase in the II/I ratio or development of antibody reactive with HSV-2-specific glycoprotein G were rare and no significant differences between the patients and control subjects were detected. This indicates that the development of the disease was apparently not followed by immediate or early activation of latent HSV-2 infection.

Antibodies, Viral↗
PubMed1986

Autoradiography of 3H-uridine incorporation in the normal early blastocysts of cattle.

RNA synthesis in morphologically normal early bovine blastocysts collected 7 days after insemination was investigated using fine-structure autoradiography after 3H-uridine incorporation. The level of autoradiographic labelling is proposed as a criterion for assessing metabolic activity in the individual cells of the blastocyst. There was a detectable difference between the cells of the trophoblast and those of the inner cell mass (higher labelling), indicating a divergence of metabolic patterns according to blastomere differentiation. The occasional absence of nuclear labelling was correlated with cell degeneration. A low nuclear labelling was observed mainly in cells sequestered in the subzonal space or in the blastocoele cavity, respectively. Estimation of RNA synthesis in different blastomeres by fine structure autoradiography opens the way to a better interpretation of the relationship between morphology and metabolism during the development of early cow embryos.

Animals↗