[Determination of the progression of prostate cancer using RT-PCR method]. / Stanovenie progresie karcinómu prostaty vyuzitím metodiky RT-PCR.

The aim of our study was to verify possible utilization of RT-PCR method (Reverse Transcriptase-Polymerase Chain Reaction) as a diagnostic and prognostic modality of the progression of prostate cancer. This approach is commonly used for the detection of circulating carcinomatous cells in peripheral blood of patients with malignant breast tumors, and our ambition was to adopt this method for patients with prostate cancer. The contribution of this method consists in its ability to detect early stages of the dispersion of carcinomatous cells, so called micrometastases, in the peripheral circulation of patients. The estimation of the progression of the disease is especially important for the selection of appropriate therapy for individual patients. Using this method we analyzed 50 men: 28 patients with clinically localized or locally advanced prostate cancer, 7 patients with clinically proven metastases, 8 patients with benign prostatic hyperplasia, and 7 healthy young men.

In vitro evaluation of the cytotoxicity and genotoxicity of resorcylidene aminoguanidine in human diploid cells B-HNF-1.

RAG belongs to appropriate inhibitors of protein glycation, i.e. formation of advanced glycation end products, which are thought to be responsible for some complications of DM, including neuropathy, angiopathy, retinopathy and nephropathy. In the present study authors have evaluated the genotoxic effect of RAG on the cell culture of human neonatal fibroblasts (B-HNF-1) in regard to its potential clinical application as inhibitor of advanced glycation end products in relationships to the pathogenesis of chronic diabetic complications. The direct contact cytotoxicity assay and micronucleus test were performed. The results showed that RAG in the concentration range of 1 x 10-4 to 1 x 10-6 mol.l-1 did not induce any changes in the morphology of exposed B-HNF-1 cells. The frequency of micronuclei was not significantly increased as well. The inhibitive effect of resorcylidene aminoguanidine was directly proportional to its concentration. It can be concluded that RAG at the selected concentrations has an inhibitive effect on proliferation of the treated cells and, at the same time, does not display any genotoxic effects on B-HNF-1 cells.

An increase in reported cases of haemorrhagic fever with renal syndrome in Slovenia in early 2008.

Haemorrhagic fever with renal syndrome (HFRS) is an acute zoonotic viral disease, caused by hantaviruses. Hantaviruses infect rodents worldwide. They are transmitted to humans by aerosol from rodent excreta. Several hantaviruses are known to infect humans with varying severity.

Current problems of diagnostics and treatment of urinary incontinence in females.

The incidence and prevalence of urinary incontinence in females is high, in women older than 60 yr of age it affects 30-60 per cent of them. The etiology of urinary incontinence is multifactorial. Urinary incontinence can be classified as stress, urgent, reflex, combined urinary incontinence and paradox ischuria.

Cytotoxicity test and cytogenetic analysis of effects of aminoguanidine in vitro.

The potential genotoxic activity of chemical substances in vitro is usually assessed by the micronucleus test and by karyological analysis. Use of the fluorescent plus Giemsa (FPG) technique is also recommended in the event that positive results are found in the micronucleus test, or if there is an increased rate of structural and numerical chromosome aberrations compared with controls. The tested substance, aminoguanidine (AG), has a marked ability to inhibit the toxic effects of carbonyl products (carbonyl stress) that arise during the end-phases of non-enzymatic protein glycation both in vitro and in vivo. The importance of this ability follows the finding that the production of advanced glycation end-products (AGE) is a part of the molecular mechanism of the pathogenesis of chronic diabetic complications. The aim of this study was to test the cytotoxic and clastogenic effects of AG on cells of the diploid cell line B-HEF-2, derived from a three-month-old male fetus. The results of the test did not reveal any induction of micronucleus production in the analyzed cells at AG concentrations ranging between 1 x 10(-2) and 1 x 10(-4) mol.L-1. Karyological analysis showed no clastogenic effect of the tested substance nor any increased rate of structural chromosome aberrations. The positive properties of AG and to its potential use as a glycoxidation inhibitor and AGE production are somewhat dimmed by its ionic nature, which hampers hydrophobic interaction with the nonpolar components of biological membranes. For this reason, the authors will further study the cytotoxicity and cytogenetic analysis of Schiff bases of AG synthesis on the basis of natural aldehydes (resorcine aldehyde, pyridoxal, etc.) in which antiglycation activity has been detected.

Identification of two gene clusters involved in cyclohexanone oxidation in Brevibacterium epidermidis strain HCU.

Brevibacterium epidermidis HCU can grow on cyclic ketones and alcohols as a sole carbon source. We have previously reported the identification of two cyclohexanone-induced Bayer-Villiger monooxygenase genes by mRNA differential display. Using the related technique of Out-PCR, we have amplified large DNA fragments flanking the two monooxygenase genes. Two large gene clusters were sequenced. Several ORFs in each gene cluster encoded proteins homologous to cyclohexanol and cyclohexanone oxidation enzymes from Acinetobacter. However, the structure of these two gene clusters differs significantly from that of Acinetobacter, where the complete pathway has been described. To assess activity of these genes, they were cloned and expressed in Escherichia coli. In vivo and in vitro assays enabled us to assign functions to the expressed ORFs. These ORFs included a cyclohexanol dehydrogenase, two different epsilon-caprolactone hydrolases and two 6-hydroxyhexanoate dehydrogenases belonging to different enzyme families. Because this environmental isolate is difficult to manipulate, we cannot determine at this time which cluster is involved in the degradation of cyclohexanone under physiological conditions. However, the original differential display experiments and some of the experiments reported here suggest the involvement of both gene clusters in the oxidation of cyclic ketones.

In vitro cytotoxicity testing of coladerm membrane.

At present, biodegradable and biocompatible membranes based on collagen and glycosaminoglycans play an important role in substitutive medicine. Modern biomaterials use a chemically modified collagen-based matrix for implants with programmable biodegradability as a substitute of buccal mucosa, skin, cartilage, etc. Besides the requirements for biocompatibility and biodegradability, the membranes must be also non-toxic. Therefore, cytotoxicity testing of these materials in vitro is an integral part of introducing newly developed types of membranes into clinical practice. As a biological model for the tested COLADERM membrane, cell cultures from human embryonic fibroblasts (B-HEF-2) were used for both cytotoxicity testing as well as in tests to assess the ability of cells to proliferate on this membrane. Along with the ability of cells to grow on the surface and inside the membrane, immunohistochemical examination and scanning electron microscopy (SEM) were performed as well. The obtained results have shown that the COLADERM membrane is non-toxic with suitable structural and biological properties for clinical application as a substitute of buccal mucosa following surgical ablation of malignant tissues from the oral cavity.

Not only fibroblasts but also melanoma cells express "leucine aminopeptidase" activity.

"Leucine aminopeptidase" (LAP, aminopolypeptidase, EC 3.4.11) activity has been recommended and widely used as a histochemical marker for the identification of contaminating LAP-positive fibroblasts in pigment cell cultures. Using a sensitive biochemical assay with L-leucyl-p-nitroanilide as a substrate we demonstrated that in vitro melanoma cells also exhibit LAP activity. Our comparison of four melanoma cell lines with four fibroblast lines showed that the differences in the enzyme activity were not qualitative but only quantitative. For this reason the specific antibodies, karyological analysis and electron microscopy are recommended as more reliable means in distinguishing fibroblasts from poorly differentiated pigment cells than the LAP-cytochemistry.

Simultaneous identification of two cyclohexanone oxidation genes from an environmental Brevibacterium isolate using mRNA differential display.

The technique of mRNA differential display was used to identify simultaneously two metabolic genes involved in the degradation of cyclohexanone in a new halotolerant Brevibacterium environmental isolate. In a strategy based only on the knowledge that cyclohexanone oxidation was inducible in this strain, the mRNA population of cells exposed to cyclohexanone was compared to that of control cells using reverse transcription-PCR reactions primed with a collection of 81 arbitrary oligonucleotides. Three DNA fragments encoding segments of flavin monooxygenases were isolated with this technique, leading to the identification of the genes of two distinct cyclohexanone monooxygenases, the enzymes responsible for the oxidation of cyclohexanone. Each monooxygenase was expressed in Escherichia coli and characterized. This work validates the application of mRNA differential display for the discovery of new microbial metabolic genes.

Cytotoxic interactions of Zn2+ in vitro: melanoma cells are more susceptible than melanocytes.

Previous studies have shown that sensitivity to high extracellular levels of Zn2+ is a general feature of cells in vitro and that a prerequisite of the toxic action of zinc is entry into cells via channels that are shared with iron or calcium. As the biochemical and toxicological behaviour of zinc chelate complexes could be different from that of free Zn2+, the effect of chelating agents on zinc transport into human melanoma cell lines was tested. EDTAcal and tetracycline reduced the toxic action of zinc ions in vitro, whereas phenytoin and diethyldithiocarbamate potentiated its effects. D-penicillamine, an effective chelator of zinc in vivo, also exerted a protective action in vitro. Comparison of sensitivity to Zn2+ in vitro between human melanoma lines and several lines of pigment cells from skin of various origins demonstrated that melanoma cells are killed by zinc ions at concentrations which are only partially toxic for normal pigment cells. This is consistent with the repeatedly observed high uptake of 65Zn by melanoma cells.

In vitro inhibition of human cytomegalovirus replication by calcium trinatrium diethylenetriaminepentaacetic acid.

Desferrioxamine (DFO) has been shown to inhibit human cytomegalovirus (CMV) replication in vitro. In the present study, we compared antiviral effects of DFO in human foreskin fibroblast (HFF) cells against several CMV strains with those of other chelators that interact with iron and other ions from different pools. DFO, a hydrophilic chelator, that may chelate both intracellular and extracellular ions inhibited production of CMV late antigen at 50% effective concentrations (EC50S) ranging from 6.2 to 8.9 microM. EC50S for calcium trinatrium diethylenetriaminepentaacetic acid (CaDTPA) ranged from 6.1 to 9.9 microM. EC50S for 2,2'-bipyridine (BPD), a hydrophobic chelator, which diffuses into cell membranes ranged from 65 to 72 microM. Concentrations which inhibited BrdU incorporation into cellular DNA by 50% (IC50S) ranged from 8.2 to 12.0 microM (DFO), from 65 to 89 microM (BPD), and from 139 to 249 microM (CaDTPA). CaDTPA was the only chelator which completely inhibited production of infectious virus in HFF and vascular endothelial cells at concentrations which had no significant effects on cellular DNA synthesis and growth. Addition of stoichiometric amounts of Fe3+ in the culture medium of HFF cells completely eliminated antiviral effects of DFO while antiviral effects of CaDTPA and BPD were only moderately affected. Fe2+ and Cu2+ were stronger inhibitors of CaDTPA than Fe3+; however, Mn2+ and Zn2+ completely suppressed antiviral effects of CaDTPA. The results show that CaDTPA is a novel nontoxic inhibitor of CMV replication. The antiviral activity of CaDTPA is suppressed by metal ions with a decreasing potency order of Mn2+/Zn2+ > Fe2+ > Cu2+ > Fe3+.

Approaches to prove the melanoma origin in amelanotic human melanoma cell lines.

The human melanoma B-HM8 cell line was derived from highly pigmented malignant skin melanoma. After 5 weeks of cultivation it entirely lost the pigmentation and has remained amelanotic since. Electron microscopy revealed neither premelanosomes nor melanosomes and the cells did not release detectable amount of dopa-oxidase activity into culture medium. Immunocytochemical studies using the polyclonal anti-S-100 antibody and detection of alpha-mannosidase activity in culture medium proved the melanoma origin of B-HM8 cells. Chromosomal changes in the karyotype of these cells were typical for human melanoma with chromosomes No. 1, 5, 7, 9, and 11 involved most frequently.

Chronic toxicity and micronucleus assay of the new cardioprotective agent stobadine in rats.

A 26-week oral toxicity and micronucleus assays of the new cardioprotective drug stobadine (CAS 95751-51-2), in the form of dipalmitate salt (DP 1031) were performed in Wistar rats of both sexes. DP 1031 was administered daily orally in doses of 7.07, 23.60 and 70.07 mg/kg. Physical appearance and general behaviour of the treated animals were normal, with a small deviation (hypoactivity in the highest dose group at the start of experiment). Food and water consumption as well as body weight gain exhibited similar values in the control and experimental groups of animals. No drug-related changes were noted in the haematological, biochemical, histopathological and genotoxicological examinations. Neither sex differences nor dose-related changes were noted under these conditions.

In vitro micronucleus test of the cardioprotective agent stobadine. A genotoxicological study.

The genotoxic effect of stobadine (1) was studied in vitro using the micronucleus test. Hamster and human fibroblastoid cells were used. In hamster cells, the highest concentration of 1 (1.10(-3) mol/l) caused a significant elevatin in the number of micronuclei, while in human cells no positive response was found for either of the concentrations used. Stobadine had no genotoxic effect on human fibroblastoid cells.

A genotoxicological study of hexachlorobenzene and pentachloroanisole.

The potential mutagenic activity of hexachlorobenzene (HCB) and pentachloroanisole (PCA) was investigated. No genotoxicity after application on Salmonella typhimurium (Ames test), Escherichia coli, and human peripheral blood lymphocytes in vitro was observed.

Clonal variation in the production of tumor-associated alpha 2-macroglobulin in a malignant human melanoma and association with growth stimulation.

alpha 2-Macroglobulin (alpha 2-M) is known as a wide-spectrum proteinase inhibitor and to bind covalently certain growth factors. We have previously characterized tumor-associated alpha 2-M synthesized and secreted by human tumor cell lines. Of the cell lines studied, the melanoma cell line HMB-2 produced the largest amount of this glycoprotein. Immunofluorescence staining of cultured HMB-2 cells suggested that the cell population is heterogeneous with respect to alpha 2-M production. We have now isolated clones from the parental HMB-2 cells and characterized eight representative ones in detail. They varied considerably in the quantity of alpha 2-M secreted, from 4.2 to 46.5% of total protein. No relationship between the production of alpha 2-M by these clones and their pigmentation or tumorigenicity in nude mice was found. However, statistically there was a strong correlation between the modal chromosome number and population doubling time (r2 = 0.88, P less than 0.001) and also between the modal chromosome number and alpha 2-M production (r2 = 0.73, P less than 0.01). The growth rate of the clones correlated with the level of alpha 2-M in culture medium (r2 = 0.69, P less than 0.01). Clones with lower alpha 2-M production had a proportionally shorter population doubling time than the clones with intermediate or high production. Northern hybridization indicated quantitative variation in the alpha 2-M mRNA expressed by the parental cells and the clones, that was comparable but not identical with the quantity of alpha 2-M in the respective culture media; both parental cells and clones expressed platelet-derived growth factor A-chain mRNAs with little difference in levels. Serum-free medium from low alpha 2-M producer clones stimulated normal stationary fibroblasts significantly more than clones producing intermediate or high amounts of alpha 2-M. alpha 2-M decreased and anti-alpha 2-M IgG increased the stimulation. These results suggest that production of tumor-associated alpha 2-M is related to both autocrine and paracrine growth-stimulating activity of the tumor cells.