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Biomedical subjects

A Pogacnik

Publications and source records attributed to A Pogacnik.

17 recordsLinked to original sources
PubMed2001

Dopamine D2 receptor mRNA measured in serial sections of the rat anterior pituitary.

Dopamine D2 receptors (D2-Rs) on lactotrophs in the pituitary gland are targets for dopamine to inhibit prolactin synthesis and release. The aim of our study was to examine if subpopulations of cells in the anterior pituitary that respond differently to dopamine show different pattern of D2-R mRNA expression. Therefore, we have used quantitative in situ hybridization technique to study the localisation of D2-R mRNA in the rat adenohypophysis. Pituitary tissue was obtained from mature and 18 days old rats. Riboprobe was transcribed from rat pituitary cDNA clone encoding D2-R and hybridized in situ with the serial sections of the pituitaries. Our results show that, although the anterior lobe of the pituitary gland contains a variety of cell types distributed in clusters, D2-R mRNA is relatively evenly distributed through the adenohypophysis. Level of expression of D2-R mRNA in the pituitary is slightly higher in mature than in young rats.

Animals↗
PubMed2001

Growth dynamics of lipizzan horses and their comparison to other horse breeds.

A typical body format of Slovenian Lipizzan horse was investigated. The study included 6 foals (5 colts and 1 filly) at the Lipica stud farm. They were measured from birth to twenty-seven months and again at forty-four months of age. Measurements included body length, chest circumference, withers height and body mass. All those measurements were statistically evaluated and compared to some other horse breeds to determine the similarity of the growth dynamics of those horse breeds. It was concluded that the parameters of the head and neck reached their full growth at the age of 27 months and also exceeded the values of their parents. The same results were obtained with the length and heights of the body (body length, withers height, etc.) and with the parameters of the front and hind legs. However the girth width, hip width and some other parameters had not yet reached their full growth at 27 months. We observed different growth dynamics with the body weight. The parameter continued to grow after 27 months of age. The same growth dynamics also seem to apply to other investigated horse breeds although the actual measurements were slightly different.

Animals↗
PubMed2001

Bioconcentration of lipophilic organochlorines in ovine dentine.

The bioconcentration of lipophilic organochlorines in ovine dentine in comparison to adipose tissue was examined. Sheep were given a single dose (0.2-1.4 mg/kg body wt) of individual polychlorobiphenyl (PCB) congeners (tetrachlorobiphenyls IUPAC Nos. 54 and 80, and hexachlorobiphenyls IUPAC Nos. 155 and 169) and organochlorine pesticides 1,1-bis(4-chlorophenyl)-2,2-dichloroethene) (4,4'-DDE) and hexachlorobenzene (HCB). They were killed 2 months after the dose and teeth and adipose tissue were collected. For the extraction of organochlorines, dentine was treated ultrasonically with sulfuric acid and hexane. The concentration of organochlorines in dentine and adipose tissue was determined by high-resolution gas chromatography with electron-capture detection. The bioconcentration of 'planar' compounds (PCB-169, HCB) in dentine, compared to adipose tissue, was lower than that of 'non-planar' (PCB-155, 4,4'-DDE). Ratios of the non-planar to planar compounds PCB-155/-169 and 4,4'-DDE/HCB in dentine were 1.4 and 7.2, and in adipose tissue 0.5 and 2.4, respectively. The dentine:adipose tissue bioconcentration ratios (on a lipid basis) of PCB-54, -80, -155, -169, 4,4'-DDE and HCB were 47, 16, 0.3, 0.1, 3.2 and 1.0, respectively. The results indicate that the bioconcentration of organochlorines in different tissues cannot be based on lipid content only. It is suggested that the physicochemical properties of individual organochlorines, i.e. lipophilicity (K(ow)), diffusivity, metabolism and tissue-specific interactions, play a part in the different bioconcentrations of individual organochlorine pollutants in dentine compared to adipose tissue.

Adipose Tissue↗
PubMed1999

Tissue distribution of planar and non-planar chlorobiphenyls, 4,4'-DDE and hexachlorobenzene in sheep and lambs.

The bioconcentration and distribution pattern of individual PCB congeners (IUPAC Nos: -54, -80, -155 and -169) and organochlorine pesticides (HCB and 4,4'-DDE) in blood, adipose tissue, liver and brain were examined in sheep two months after administration and in their offspring continuously exposed during the two months lactation period. Analyses were performed by high resolution gas chromatography. The levels of individual organochlorines varied significantly between tissues; the tissue/blood ratio (on a fat basis) varied by two orders of magnitude for individual congeners. The bioconcentration of the toxic planar PCB-169 congener was the highest in the liver and the lowest in the brain of the sheep.

Adipose Tissue↗
PubMed1996

Morphometric analysis of fetal rat lung after the administration of Pyralene-3000.

The effects of the application of commercial low chlorinated PCB Pyralene-3000 on rat lung development during late gestation were studied. In the developing lungs (17.5 to 21.5 days) the volume density (Vv) of a particular compartment and length density of potential air spaces (Lv) were determined. Significant difference (p < 0.01) in epithelium to mesenchyme ratio (Epi/Mes) occurred between the control and treated groups on day 20.5 due to an increased volume proportion of mesenchyme (Vvmes) in the treated group suggesting a small delay in maturation. Decreased volume proportion of potential airspaces (Vvair) was observed on days 18.5 and 20.5. However, no differences were found on day 21.5 in any variables studied.

Animals↗
PubMed1996

Transfer of planar and non-planar chlorobiphenyls, 4,4'-DDE and hexachlorobenzene from blood to milk and to suckling infants.

The transfer coefficients of tetra- and hexachlorobiphenyls (PCB-54; -80; -155; and -169), HCB and 4,4'-DDE between milk and blood were monitored for eight weeks in sheep previously administered with these compounds by intramuscular injection. Analyses were performed by high resolution gas chromatography. The milk/blood ratio on a fat basis was close to 1 for HCB, over 1 for 4,4'-DDE, PCB-155, and -169 and below 1 for PCB-54 and -80. It is speculated that the deviation from the ratio 1 results from the interactions of organochlorines with (lipo)proteins in blood and/or milk. In milk, the enrichment of 4,4'-DDE, PCB-155 and -169 was observed. The relative toxicity expressed by the toxic equivalent (on a fat basis) was approximately 2.5 times higher in milk than in blood.

Animals↗
PubMed1995

Combined histochemical and immunohistochemical determination of three muscle fibre types in a single section of porcine skeletal muscle.

The method of successive staining for SDH and immunohistochemical detection of fast contracting muscle fibres in pig muscle tissue has been used for demonstration of three muscle fibre types (slow oxidative, SO; fast metabolic intermediate, FI; fast glycolytic, FG). It gives basic information on contractile and metabolic muscle fibre properties in a single frozen section and can be well applied to the pale, soft and exudative (PSE) changes affecting pig muscles.

Adenosine Triphosphatases↗
PubMed1993

Calcitonin- and somatostatin-positive cells in thyroid gland of pigs at different ages.

Immunohistochemical studies were carried out on calcitonin-, somatostatin- and serotonin-reactive cells in newborn pigs and pigs at 3 weeks and 7 months old. The aim of these studies was to examine if the expression of various bioactive substances by parafollicular cells in the pig thyroid varied during development. The volume density of the follicular epithelium was nearly the same in newborn and 3-week-old piglets and significantly lower in 7-month-old animals. The volume density of calcitonin-positive cells, expressed as a percentage of the follicular epithelium density, was similar in young animals, being 12.10% and 13.03% in newborn and 3-week-old piglets, respectively. A small but significant increase to 14.40% was seen in 7-month-old pigs. Somatostatin-positive cells formed a much smaller population at all time points, but these also showed a significant increase with age (0.13%, 0.17% and 0.52% of follicular epithelium density in newborn, 3-week- and 7-month-old pigs, respectively). However the changes in the volume density of somatostatin-positive cells correlated inversely with thyroid activity, the density being highest when the activation index was lowest, suggesting that thyroid activity may be regulated by an increase in the synthesis of this inhibitory peptide. Serotonin-positive cells were extremely rare at all time points and their volume density was not calculated.

Age Factors↗
PubMed1993

Preparation of fine needle aspiration biopsy samples for flow cytometric analysis.

In order to improve the quality of flow cytometric (FCM) DNA histograms, a new preparatory method was tested on samples obtained by fine needle aspiration biopsy (FNAB) of breast tumors. Twenty-four samples were obtained in vivo (group 1), and 20 were obtained from surgically resected specimens (group 2). Tumors from both groups were aspirated twice each. The first sample was injected directly into 70% ethanol, whereas the second sample was pretreated with a mixture of Tween-20 and citric acid solution (Tween-20 CA) before ethanol fixation. The coefficient of variation (CV) of G0-G1 peaks of Tween 20 CA-pretreated samples varied from 1.85 to 5.10 (mean, 3.3) in group 1 and from 1.87 to 3.72 (mean, 2.77) in group 2. The CV of G0-G1 peaks of ethanol-preserved samples ranged from 2.28 to 7.22 (mean, 5.23) in group 1 and from 1.78 to 4.04 (mean, 3.48) in group 2. The CV values of histograms obtained by the new protocol were significantly lower (group 1, P < .05; group 2, P < .01).

Analysis of Variance↗
PubMed1990

Results of combined modality treatment in poorly differentiated and anaplastic thyroid carcinoma.

From 1973-1989 34 patients with poorly differentiated primarily inoperable and 89 with anaplastic giant-cell thyroid tumours entered a study on individualized multimodal treatment. The aim of the study was to find an effective, non-aggressive chemotherapy (ChT) and explore the possibility of individualized combined treatment. Infusions of low doses of vinblastine or cisplatinum or adriamycin or novantrone were used for perturbation of cellular kinetics in the tumours. Sequential fine-needle aspiration biopsies of tumours were performed for monitoring the drug-induced changes in tumour cells and for cytomorphological studies and DNA measurements, on the basis of which ChT was individualized. During the period of accumulation of cells in the S or G2 + M phases, drugs particularly effective in the respective phases were used. The same principle was used in planning a combination of ChT and irradiation. In the group of poorly differentiated carcinomas only 5/34 patients had MR to ChT. In 17/34 patients after ChT the tumour was removed surgically, 19/34 have NED 11+ to 72+ months after treatment. The results in 89 patients with anaplastic carcinoma are worse: 13/89 patients died before or at the beginning of treatment, of 77 treated patients only 10 could be operated on, 7 survived for more than one year (13+ to 72+ months). Only 1/77 patients survived for more than 5 years. A combination of DNA measurements and cytomorphological studies is a useful method for the understanding of tumour behaviour under treatment.

Adult↗
PubMedDate not supplied

Sampling, sampling errors and specimen preparation.

To obtain an adequate cervical smear for making a correct cytologic diagnosis, smear taking, laboratory handling and interpretation must be optimal. Many people are involved, and only by a combined effort of all links can this target be seriously approached: the smear takers will have to be open minded about technical improvements and read the morphologic descriptions cautiously; in the laboratory, cytotechnicians and physicians will have to challenge themselves and each other. It is mandatory to discard specimens that do not meet general standards of adequacy. At present a host of new techniques are being implemented. It is not feasible for all laboratories to be engaged in testing these new methods, but we are all requested to follow the development the best we can and switch to new ways when justified. Our working conditions are very different; therefore, it is our professional responsibility and plight to respond at the right time. So far the conclusion is that the conventional Pap smear is the international standard of care for the diagnosis of cervical cancer precursers in cancer screening programs. Certainly, this may change within a very short time. Liquid-based techniques, and in particular HPV technologies, are just around the corner.

Cell Biology↗
PubMedDate not supplied

Malignant rhabdoid tumor of the liver diagnosed by fine needle aspiration cytology. A case report.

BACKGROUND: Primary malignant rhabdoid tumor (MRT) of the liver is a rare tumor of early infancy, with a grim prognosis. CASE: A 17-month-old female presented with a palpable mass in the upper right side of the abdomen. Ultrasonographically guided fine needle aspiration biopsy of the tumor contained malignant cells with medium-sized, vesicular nuclei; prominent nucleoli; and well-defined cytoplasm exhibiting paranuclear, dense inclusions. These inclusions reacted positively with cytokeratin and vimentin. Ultrastructural examination showed the presence of intermediate cytoplasmic filaments. CONCLUSION: Cytomorphologic and immunocytochemical characteristics permit the preoperative differentiation of MRT from other malignant tumors of childhood. That facilitates treatment planning and precludes unnecessary surgical intervention.

Biopsy, Needle↗