Cloning of the genes for non-medullary thyroid cancer: Methods and advances

In last ten years, significant advances have occurred in thyroid endocrinology, as a consequence of the generalized use of molecular biology techniques. New genes involved in the development of thyroid cancer have been identified, which had a great impact on our understanding of thyroid cancer predisposition. All cancers are genetic in origin because they arise from mutations in a single somatic cell, but the genetic changes in sporadic cancers are confined to a particular tissue. In inherited cancers, a predisposing mutation is present in all somatic cells and in the germ line, which enables the transmission of risk to the next generation. Cancer genetics offers a model of how information on the genetics of inherited cancers could affect identification of individuals at increased genetic risk

Intestinal alkaline phosphatase activity as a molecular marker of enterotoxicity induced by single dose of 5-fluorouracil and protective role of orally administered glutamine

Background. One of the critical limitations for the administration of the chemotherapy is the toxicity affecting normal tissue. The main target organs for 5-fluorouracil (5-FU) toxicity in humans and experimental animals are the gastrointestinal tract, bone marrow, and skin. The cytotoxic effects of antimetabolite chemotherapy are based on their role as substrates for the same transport processes and enzymes involved in anabolism and catabolism as the natural substrates. The main goal of our study was to analyze the dose-dependent antiproliferative effects of 5-FU on intestinal mucosa, enterotoxic potential of 5-FU in experimental animals and to test possible protective role of glutamine. Methods. In our study, we used Sprague Dawley rats. The control group of rats included 50 animals, while the groups where either 5-fluorouracil (5-FU) alone or 5-FU and glutamine were administered included 200 animals. All experimental animals were further stratified according to the experimental model (25 animals in each of 8 experimental subgroups of animals). The 5-FU was administered by intraperitoneal application in single dose of 0, 100, 200, 300, and 400 mg of 5-FU per kg of body weight. Water solution of 1% glutamine was prepared daily and administered orally, in volume of 200 ml, for 7 days continuously, after the 7th day of 5-FU administration. Experimental animals were sacrificed 7 days after the administration of 5-FU. The isolation of enterocytes was performed according to the method of Kralovansky et al. In cell homogenate obtained by described method, we determined the protein content using the Biuret method and the DNA content using the Burton reagent. The activities of enzymes alkaline phosphatase (ALP), glutathione S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPX) were determined by kinetic method. All paraffin samples of the small intestine were stained by haematoxiline and eosine(HE method). All the experiments were done in duplicate and analyzed by standard statistical methods. All the experiments were done in duplicate and analyzed by standard statistical methods. Results: Our results of enterotoxicity induced by intraperitonealy administered 5-FU showed statistically significant decrease of DNA content in small intestine samples of experimental animals, decrease in activity of intestinal alkaline phosphatase enzyme and the increase in glutathione-dependent enzymes. The glutamine supplementation reduced 5-FU intestinal toxicity. Conclusion: Intestinal alkaline phosphatase is a good marker of the dose-dependent enterotoxicity induced by 5-fluorouracil

Drug interference with biochemical laboratory tests

Clinical laboratory practice represents an essential part of clinical decision-making, as it influences 60-70% of medical decisions at all levels of health care. Results of biochemical laboratory tests (BLTs) have a key role in establishment of adequate diagnosis as well as in evaluation of treatment progress and outcome. The prevalence of drug-laboratory test interactions (DLTIs) is up to 43% of patients who had laboratory results influenced by drugs. Unrecognized DLTIs may lead to misinterpreted BLTs results, incorrect or delayed diagnosis, extra costs for unnecessary additional tests or inadequate therapy, as all may cause false clinical decisions. The significance of timely and adequate recognition of DLTIs is to prevent common clinical consequences such as incorrectly interpreted test results, delayed or non-treated condition due to erroneous diagnosis or unnecessary extra tests or therapy. Medical professionals should be educated that it is essential to obtain patient data about medications especially for the drugs used in the last 10 days before biological material collection. Our mini-review aims to provide a comprehensive overview of the current state in this important domain of medical biochemistry with detailed analysis of the effect of drugs on BLTs and to give detailed information to medical specialists

Review paper DIAGNOSTICS OF HEREDITARY MALIGNANCIES

Summary: Significant advances have occurred in our understanding of the cancer etiology in the last decade, as a consequence of the generalized use of molecular biology techniques in human genetics. Cancer is a form of a complex genetic disease. Most forms of cancer are characterised by the accumulation of different genetic alterations affecting genes from a set of genes with pathogenic potential, which is specific for each tumour entity. While in the majority of malignant tumours these changes are somatically acquired, some mutations are transmitted through the germline and account for an inherited tumour predisposition. The next frontier in cancer genetics is to find genes with high prevalence alleles conferring a low increase or decrease of cancer risk. Key words: diagnostics, cancer, hereditary malignancie

Oxyphilic carcinoma of the thyroid gland

Oxyphilic tumors of the thyroid gland are rare tumors characterized by the presence of Hürthle cells - mitochondrion-rich, eosinophilic epithelial cells. Hürthle cell carcinomas (HCC) of the thyroid behave in a more aggressive fashion as compared to other well-differentiated thyroid cancers. Many recent studies have been focused on the further elucidation of pathogenesis and the role of mitochondrial hyperplasia in carcinogenesis of these neoplasms. The importance of combining morphological and genetic approaches in the study of HCC has been emphasized by the difficulties encountered in establishing adequate differential diagnostic criteria between benign and malignant forms, as well as by the resistance of HCC to radio and chemotherapy. It has been well documented that the Hürthle cells are characterized by profound aberrations in the nuclear and mitochondrial genome and by alterations in oncogenes, tumor suppressor genes and other key genes involved in energy metabolism, proliferation and apoptosis

The Impact of Farnesoid X Receptor Activation on Intestinal Permeability in Inflammatory Bowel Disease

The most important function of the intestinal mucosa is to form a barrier that separates luminal contents from the intestine. Defects in the intestinal epithelial barrier have been observed in several intestinal disorders such as inflammatory bowel disease (IBD). Recent studies have identified a number of factors that contribute to development of IBD including environmental triggers, genetic factors, immunoregulatory defects and microbial exposure. The current review focuses on the influence of the farnesoid X receptor (FXR) on the inhibition of intestinal inflammation in patients with IBD. The development and investigation of FXR agonists provide strong support for the regulatory role of FXR in mucosal innate immunity. Activation of FXR in the intestinal tract decreases the production of proinflammatory cytokines such as interleukin (IL) 1-beta, IL-2, IL-6, tumour necrosis factor-alpha and interferon-gamma, thus contributing to a reduction in inflammation and epithelial permeability. In addition, intestinal FXR activation induces the transcription of multiple genes involved in enteroprotection and the prevention of bacterial translocation in the intestinal tract. These data suggest that FXR agonists are potential candidates for exploration as a novel therapeutic strategy for IBD in humans

Changes of biochemical parameters in rat intestinal mucosa induced by methotrexate and effects of enteral administration of glutamine

BACKGROUND: Rapidly proliferating crypt cells of the intestinal epithelium, the precursors of the mature enterocytes, are extremely sensitive to the effects of cytostatic agents. We investigated the effects of the methotrexate on rat intestinal mucosa in order to get the information on biochemical indicators of intestinal damage. METHODS: Biochemical parameters were investigated in isolated intestinal mucosa of Sprague-Dawley rats, previously treated with methotrexate by intraperitoneal administration. Glutamine was dissolved in water and administered orally. RESULTS: The activity of glutaminase and alkaline phosphatase showed the enzymatic response to different doses of methotrexate. The activity of both enzymes was significantly lower in the mucosa of treated animals, compared to control group. CONCLUSION: Minimal mucosal damage and regeneration time is dose dependent and influenced by the dosage schedule of antitumor therapy

Review article UDC: 616.441-006:576.385.5:577.21 Archive of Oncology 2003;11(2):81-9. Oxyphilic carcinoma of the thyroid gland

Oxyphilic tumors of the thyroid gland are rare tumors characterized by the presence of HŸrthle cells- mitochondrion-rich, eosinophilic epithelial cells. HŸrthle cell carcinomas (HCC) of the thyroid behave in a more aggressive fashion as compared to other well-differentiated thyroid cancers. Many recent studies have been focused on the further elucidation of pathogenesis and the role of mitochondrial hyperplasia in carcinogenesis of these neoplasms. The importance of combining morphological and genetic approaches in the study of HCC has been emphasized by the difficulties encountered in establishing adequate differential diagnostic criteria between benign and malignant forms, as well as by the resistance of HCC to radio and chemotherapy. It has been well documented that the HŸrthle cells are characterized by profound aberrations in the nuclear and mitochondrial genome and by alterations in oncogenes, tumor suppressor genes and other key genes involved in energy metabolism, proliferation and apoptosis

Glutathione S-transferase T1 and M1 polymorphisms and risk of thyroid neoplasms

Background: In order to test the possibility of association between GSTT1 and M1 (glutathione S-transferase) null allele variant, in which the entire gene is absent, and the risk of TCO (thyroid carcinoma with cell oxyphilia), the case-control study was carried out. Methods: Genotypes for GSTT1 and GSTM1 were determined by multiplex PCR in the DNA from 108 healthy individuals and in DNA from samples of thyroid tumors from 130 patients of the same race and origin as the control group (Caucasian, Italian). The following types of NMTC were analyzed: oxyphilic adenoma (OA), oxyphilic carcinoma (OC) papillary thyroid carcinoma with oxyphilic features (PTCof), follicular adenoma (FA), follicular carcinoma (FC), follicular variant of PTC (fvPTC) and classical PTC. Associations between prevalence of particular genotypes and the occurrence of TCO (versus controls) and other subtypes of NMTC were tested. Associations were quantified by calculating OR (odds ratio) with 95% confidence interval. StatGraphics Plus v. 5 software (Manugistics) was used for statistical analysis. Results: In this study of the association between the GSTT1 and M1 null genotype and the increased risk of TCO, the frequency of GSTT1 null genotype of 19.2% in cases and 15.7% in controls was found with an adjusted odds ratio (OR) of 1.4 (95% confidence interval (CI) 0.70-2.81), and the frequency of GSTM1 null genotype of 59% in cases with oxyphilic tumors and of 55.6% in controls (OR 1.24; 95% CI, 0.62-2.48). Conclusion: These results indicate that the GSTT1 and M1 null genotypes do not increase the risk of development of oxyphilic tumors, as well as other types of NMTC that have been included in this study

Original article UDC: 577.11:547.466.64:577.15

Changes of biochemical parameters in rat intestinal mucosa induced by methotrexate and effects of enteral administration of glutamin