Erika Halasova

Brainstem circuitry of tracheal-bronchial cough: c-fos study in anesthetized cats.

The c-fos gene expression method was used to localize brainstem neurons functionally related to the tracheal-bronchial cough on 13 spontaneously breathing, pentobarbitone anesthetized cats. The level of Fos-like immunoreactivity (FLI) in 6 animals with repetitive coughs (170+/-12) induced by mechanical stimulation of the tracheobronchial mucosa was compared to FLI in 7 control non-stimulated cats. Thirty-four nuclei were compared for the number of labeled cells. Enhanced cough FLI was found bilaterally at following brainstem structures, as compared to controls: In the medulla, FLI was increased in the medial, interstitial and ventrolateral subnuclei of the solitary tract (p < 0.02), in the retroambigual nucleus of the caudal medulla (p < 0.05), in the ambigual, paraambigual and retrofacial nuclei of the rostral medulla along with the lateral reticular nuclei, the ventrolateral reticular tegmental field (p < 0.05), and the raphe nuclei (p < 0.05). In pons, increased FLI was detected in the lateral parabrachial and Kölliker-Fuse nuclei (p < 0.01), in the posteroventral cochlear nuclei (p < 0.01), and the raphe midline (p < 0.05). Within the mesencephalon cough-related FLI was enhanced at the rostral midline area (p < 0.05), but a decrease was found at its caudal part in the periaqueductal gray (p < 0.02). Results of this study suggest a large medullary - pontine - mesencephalic neuronal circuit involved in the control of the tracheal-bronchial cough in cats.

Gene polymorphisms in bladder cancer

In Europe, cancer of the bladder is the fourth most common cancer among men, accounting for 7% of total cancers. In the USA, bladder cancer is the fifth most common cancer in men and seventh in women. This disease is three times more common in men than in women. Several risk factors, such as cigarette smoking and occupational chemical exposure, contribute to bladder cancer development. The balance between activation and detoxification of carcinogens affects the amount of DNA damage that accumulates in cells. The entire process leading to DNA damage and subsequent repair of the damage involves a host of enzymes, many of which are polymorphic. Polymorphisms in metabolic enzyme genes and repair genes may cause alterations in protein product functions that can finally lead to genomic instability and carcinogenesis. In this article, we review the polymorphisms in a number of genes that have been found to be the modulators of bladder cancer risk. Improved understanding of the molecular biology of urothelial malignancies is helping to more clearly define the role of new prognostic indices and multidisciplinary treatment for this disease.

Short reflex expirations (expiration reflexes) induced by mechanical stimulation of the trachea in anesthetized cats.

Fifty spontaneously breathing pentobarbital-anesthetized cats were used to determine the incidence rate and parameters of short reflex expirations induced by mechanical stimulation of the tracheal mucosa (ERt). The mechanical stimuli evoked coughs; in addition, 67.6% of the stimulation trials began with ERt. The expiration reflex mechanically induced from the glottis (ERg) was also analyzed (99.5% incidence, p < 0.001 compared to the incidence of ERt). We found that the amplitudes of abdominal, laryngeal abductor posterior cricoarytenoid, and laryngeal adductor thyroarytenoid electromyograms (EMG) were significantly enhanced in ERg relative to ERt. Peak intrathoracic pressure (esophageal or intra-pleural pressure) was higher during ERg than ERt. The interval between the peak in EMG activity of the posterior cricoarytenoid muscle and that of the EMG of abdominal muscles was lower in ERt compared to ERg. The duration of thyroarytenoid EMG activity associated with ERt was shorter than that in ERg. All other temporal features of the pattern of abdominal, posterior cricoarytenoid, and thyroarytenoid muscles EMGs were equivalent in ERt and ERg.In an additional 8 cats, the effect of codeine administered via the vertebral artery was tested. Codeine, in a dose (0.03 mg/kg) that markedly suppressed cough did not significantly alter either the incidence rate or magnitudes of ERt.In the anesthetized cat the ERt induced by mechanical stimulation of the trachea was similar to the ERg from the glottis. These two reflex responses differ substantially only in the frequency of occurrence in response to mechanical stimulus and in the intensity of motor output.

The Molecular and Cellular Effect of Homocysteine Metabolism Imbalance on Human Health

Homocysteine (Hcy) is a sulfur-containing non-proteinogenic amino acid derived in methionine metabolism. The increased level of Hcy in plasma, hyperhomocysteinemia, is considered to be an independent risk factor for cardio and cerebrovascular diseases. However, it is still not clear if Hcy is a marker or a causative agent of diseases. More and more research data suggest that Hcy is an important indicator for overall health status. This review represents the current understanding of molecular mechanism of Hcy metabolism and its link to hyperhomocysteinemia-related pathologies in humans. The aberrant Hcy metabolism could lead to the redox imbalance and oxidative stress resulting in elevated protein, nucleic acid and carbohydrate oxidation and lipoperoxidation, products known to be involved in cytotoxicity. Additionally, we examine the role of Hcy in thiolation of proteins, which results in their molecular and functional modifications. We also highlight the relationship between the imbalance in Hcy metabolism and pathogenesis of diseases, such as cardiovascular diseases, neurological and psychiatric disorders, chronic kidney disease, bone tissue damages, gastrointestinal disorders, cancer, and congenital defects.

Chromosomal damage among medical staff occupationally exposed to volatile anesthetics, antineoplastic drugs, and formaldehyde.

OBJECTIVES Structural chromosomal aberrations in blood lymphocytes represent a biomarker for cellular damage caused by genotoxic carcinogens and are an indicator of increased cancer risk. We evaluated the association between frequencies of total chromosomal aberrations, chromatid- and chromosome-type aberrations, and occupational exposures to volatile anesthetics, antineoplastic agents, and formaldehyde among 601 medical professionals. METHODS Chromosomal damage among exposed individuals and unexposed controls was determined by conventional cytogenetic analysis. We used binary logistic regression to evaluate the effects of workplace exposures and major confounders on chromosomal damage. RESULTS Significantly higher frequencies of total chromosomal, chromatid-type and chromosome-type aberrations were observed among subjects occupationally exposed to volatile anesthetics, antineoplastic agents, and formaldehyde compared to age- and sex-matched controls (P<0.0001). The risk of an increased frequency of chromosomal aberrations was associated with exposure to anesthetics [odds ratio (OR) 3.9, 95% confidence interval (95% CI) 2.7-5.8], cytostatics (OR 2.7, 95% CI 1.9-3.9), and formaldehyde (OR 1.7, 95% CI 1.1-2.7). No other covariate contributed significantly to the model. Chromatid- and chromosome-type aberrations were associated with exposure to anesthetics and cytostatics without any contribution of other variables. Stratified data analysis showed the risk of increased chromosomal aberrations among non-smoking female nurses and physicians exposed to anesthetics, cytostatics and, partially, formaldehyde. Chromatid and chromosome exchanges were significantly higher in the exposed groups than among controls. CONCLUSION Our findings indicate that the presence of genotoxic compounds in operating rooms, oncological units, and pathological departments results in a significant increase of chromosomal damage (impair of chromosomal integrity) among medical workers employed in these facilities.

Chromosomal aberrations in tire plant workers and interaction with polymorphisms of biotransformation and DNA repair genes

We evaluated chromosomal aberrations in lymphocytes of 177 workers exposed to xenobiotics in a tire plant and in 172 controls, in relation to their genetic background. Nine polymorphisms in genes encoding biotransformation enzymes and nine polymorphisms in genes involved in main DNA repair pathways were investigated for possible modulation of chromosomal damage. Chromosomal aberration frequencies were the highest among exposed smokers and the lowest in non-smoking unexposed individuals (2.5+/-1.8% vs. 1.7+/-1.2%, respectively). The differences between groups (ANOVA) were borderline significant (F=2.6, P=0.055). Chromosomal aberrations were higher in subjects with GSTT1-null (2.4+/-1.7%) than in those with GSTT1-plus genotype (1.8+/-1.4%; F=7.2, P=0.008). Considering individual groups, this association was significant in smoking exposed workers (F=4.4, P=0.040). Individuals with low activity EPHX1 genotype exhibited significantly higher chromosomal aberrations (2.3+/-1.6%) in comparison with those bearing medium (1.7+/-1.2%) and high activity genotype (1.5+/-1.2%; F=4.7, P=0.010). Both chromatid- and chromosome-type aberration frequencies were mainly affected by exposure and smoking status. Binary logistic regression analysis revealed that frequencies of chromatid-type aberrations were modulated by NBS1 Glu185Gln (OR 4.26, 95%CI 1.38-13.14, P=0.012), and to a moderate extent, by XPD Lys751Gln (OR 0.16, 95%CI 0.02-1.25, P=0.081) polymorphisms. Chromosome-type aberrations were lowest in individuals bearing the EPHX1 genotype conferring the high activity (OR 0.38, 95%CI 0.15-0.98, P=0.045). Present results show that exposed individuals in the tire production, who smoke, exhibit higher chromosomal aberrations frequencies, and the extent of chromosomal damage may additionally be modified by relevant polymorphisms.

Structural chromosomal aberrations as potential risk markers in incident cancer patients

Epidemiological prospective studies have shown that increased chromosomal aberrations (CAs) in peripheral blood lymphocytes may predict cancer risk. Here, we report CAs in newly diagnosed 101 colorectal, 87 lung and 158 breast cancer patients and corresponding healthy controls. Strong differences in distributions of aberrant cells (ACs), CAs, chromatid-type aberrations (CTAs) and chromosome-type aberrations (CSAs) were observed in lung and breast cancer patients as compared to healthy controls. In colorectal cancer (CRC) patients, only CTAs were significantly elevated. Binary logistic regression, adjusted for main confounders, indicates that all the analysed cytogenetic parameters along with smoking were significantly associated with breast and lung cancer risks. Significant differences in terminal deletions between breast cancer patients and corresponding female controls were recorded (0.39 vs. 0.18; P ≤ 0.05). We did not find any association of CAs with TNM (tumor nodus metastasis) stages or histopathological grade in either cancer type. CAs were neither associated with additional tumor characteristics-invasivity, ductal and lobular character, estrogene/progesterone receptors in breast tumors nor with non-small/small cell and bronchogenic/pulmonary types of lung tumors. Our study demonstrates that CAs serve as a predictive marker for breast and lung cancer, whereas only CTAs were elevated in incident CRC patients.

Expression of Ki-67, Bcl-2, Survivin and p53 Proteins in Patients with Pulmonary Carcinoma

Apoptosis is the fundamental process necessary for eliminating damaged or mutated cells. Alterations in the apoptotic pathway appear to be key events in cancer development and progression. Bcl-2 is the key member of the Bcl-2 family of apoptosis regulator proteins with anti-apoptotic effects. Survivin acts as an inhibitor of apoptosis as well and has been implicated in both inhibition of apoptosis and mitosis regulation. p53 is one of the tumor suppressor proteins, prevents tumor formation through cell cycle blocking and eliminates damaged cells via the activation of apoptosis. The Ki-67 protein is a cellular marker for proliferation. To investigate the possible interactions of the aforementioned proteins, we examined their expression in 76 patients with diagnosed lung cancer using immunohistochemical visualisation. Ki-67 protein was expressed in the cancer cells of all patients with small cell lung cancer (SCLC). We found a negative correlation between survivin and p53 expression. A decreased intensity of survivin expression and fewer cells positive for survivin (66.7%) in SCLC in comparison with other lung cancer types (98.0%) was detected. Reversely, expression of Bcl-2 was found in more than 90% of cases with SCLC. We hypothesize that high expression and intensity of Bcl-2 protein could be a factor behind a bad prognosis in SCLC.

Brainstem regions involved in the expiration reflex. A c-fos study in anesthetized cats.

Expression of the immediate-early gene c-fos, a marker of neuronal activation, was employed to localize brainstem neuronal populations functionally related to the expiration reflex (ER). Twelve spontaneously breathing, non-decerebrate, pentobarbital anesthetized cats were used. The level of Fos-like immunoreactivity (FLI) in 6 animals with repetitive ERs mechanically induced from the glottis (296+/-9 ERs) was compared to FLI in 6 control non-stimulated cats. Respiratory rate, arterial blood pressure, and end tidal CO(2) concentration remained stable during the experiment. In the medulla, increased FLI was found in the region of nucleus tractus solitarii (p<0.001), in the ventrolateral medulla along with the lateral tegmental field (p<0.01), and in the vestibular nuclei (p<0.01). In the pons, increased FLI was detected in the caudal extensions of the lateral parabrachial and Kölliker-Fuse nuclei (p<0.05). Within the rostral mesencephalon, FLI was enhanced in the midline area (p<0.05). A lower level of ER-related FLI compared to control animals was detected in the pontine raphe region (p<0.05) and the lateral division of mesencephalic periaqueductal gray (p<0.05). The results suggest that the ER is coordinated by a complex long loop of medullary-pontine-mesencephalic neuronal circuits, some of which may differ from those of other respiratory reflexes. The FLI related to the expulsive behavior ER differs from that induced by laryngeal stimulation and laryngeal adductor responses, particularly in ventrolateral medulla and mesencephalon.

GENE POLYMORPHISMS OF BIOTRANSFORMING ENZYMES (GSTS) AND THEIR ASSOCIATION WITH LUNG CANCER IN THE SLOVAKIAN POPULATION

ObjectiveThe aim of present study was to present the results of a case-control study focused on genetic polymorphisms of selected Phase II metabolizing enzymes (GSTM1, T1, and P1) and to investigate the association of these polymorphisms with lung cancer risk in the Slovakian population.Material and methodsThe study encompassed 160 lung cancer cases and 220 controls. DNA was extracted from peripheral blood leukocytes, and the polymorphisms of GSTM1, GSTT1 and GSTP1 enzymes were determined by PCR-based methods. We determined the genotype distribution of all these genes and their combinations. The association between specific genotypes and the development of lung cancer were examined using logistic regression analysis to calculate odds ratios (OR) and 95% confidence intervals (CI).ResultsWe found that the GSTM1 null genotype (OR = 1.6; 95% CI = 1.03-2.4; χ2 = 4.08, and P = 0.04) was associated with elevated risk. A significant correlation also was found for the combined genotypes of GSTM1 null and GSTP1 Ile/Val and Val/Val (OR = 2.01; 95% CI = 1.1-6.1; χ2 = 3.6, and P = 0.02) and GSTM1 null and GSTT1 positive (OR = 2.00; 95% CI = 1.2-3.2; χ2 = 7.3, and P = 0.006).ConclusionsWe conclude that the genotype of metabolizing enzymes and allelic combinations underscore the risk for lung cancer. Individual risk assessment may be further improved by increasing the number of polymorphisms studied and combining them with the traditional epidemiological risk factor.