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Biomedical subjects

A Pogacnik

Publications and source records attributed to A Pogacnik.

25 records · Page 2Linked to original sources
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↗