51 research outputs found
Hypermethylation of p16 and DAPK promoter gene regions in patients with non-invasive urinary bladder cancer
Wpływ melatoniny na aktywność peroksydazy glutationu w surowicy i erytrocytach po iniekcji adriamycyny u szczurów nietkniętych i poddanych pinealektomii
Introduction: Adriamycin (ADR) is a potent chemotherapeutic agent, effective in the treatment of leukaemias, lymphomas and many
solid tumours. However, its clinical usage is often limited by cardiotoxicity, induced by oxygen radical damage of the membrane lipids.
Melatonin (MEL) is a well-known antioxidant. It has been shown that MEL can scavenge free radicals, both directly and indirectly, stimulating
the activity of antioxidative enzymes such as glutathione peroxidase (GSH-Px).
The aim of the study: The aim of the study was to examine the effect of MEL on serum and erythrocyte GSH-Px activity after ADR in
normal and pinealectomised rats.
Material and methods: Wistar rats were divided into the three groups: control animals (Intact), sham-operated (Sham-PX) and pinealectomised
(Px). Each of the groups was divided into four subgroups, injected with: 1 - saline, 2 - MEL, 3 - ADR and 4 - ADR + MEL.
ADR was administered 2 months after Px as a single dose (15 mg/kg, i.p.) 1 hour after the fourth melatonin injection. Melatonin (5 mg/kg,
i.p.) was administered for 4 days before and 2 days after ADR. After 6 days of treatment, the rats were killed by decapitation. Their blood
was collected for measurements.
Results: In serum GSH-Px activity decreased in all the groups after ADR. Pinealectomy decreased the activity of the enzyme in all the
groups of animals examined. In erythrocytes GSH-Px decreased after ADR in the Px-animals. The effect of pinealectomy on erythrocyte
GSH-Px activity was not as strongly expressed as serum GSH-Px activity. MEL did not change GSH-Px activity after ADR.
Conclusion: Melatonin, in pharmacological concentrations, did not influence the activity of GSH-Px, either in normal or in pinealectomised
rats after ADR. A deficiency of endogenous melatonin production may inhibit GSH-Px activity.Wstęp: Adriamycyna (ADR, adriamycin) jest lekiem przeciwnowotworowym wykorzystywanym w leczeniu białaczek, chłoniaków czy
guzów litych. Jej efekt leczenia jest ograniczony ze względu na kardiotoksyczność indukowaną produkcją wolnych rodników, które
uszkadzają błony lipidowe.
Melatonina (MEL, melatonin) jest znanym antyoksydantem. Wykazano, że neutralizuje wolne rodniki w sposób bezpośredni lub pośredni,
stymulując enzymy antyoksydacyjne, w tym peroksydazę glutationu (GSH-Px, glutathione peroxidase).
Cel: Celem badania było zbadanie efektu melatoniny na aktywność GSH-Px w surowicy i erytrocytach po adriamycynie u zwierząt
nietkniętych i po usunięciu szyszynki.
Materiał i metody: Szczury samce szczepu Wistar podzielono na 3 grupy: grupę kontrolną (Intact - szczury nietknięte), po operacji
pozornej (Sham-Px) i po usunięciu szyszynki (Px). Każdą grupę podzielono na 4 podgrupy, w których podano injekcje: 1 - soli fizjologicznej,
2 - MEL, 3 - ADR i 4 - ADR + MEL. Adriamycynę podano 2 miesiące po Px w dawce jednorazowej (15 mg/kg mc.),
1 godzinę przed czwartym podaniem MEL. Melatoninę podawano przez 4 dni przed Px i przez 2 dni po ADR w dawce 5 mg/kg mc. Po
6 dniach leczenia zwierzęta zabito przez dekapitację, a krew zamrożono do momentu pomiarów.
Wyniki: Aktywność PSH-Px w surowicy obniżyła się po ADR we wszystkich badanych grupach. Po usunięciu szyszynki aktywność GSHPx
w surowicy zmniejszyła się w grupach poddanych injekcjom. Aktywność GSH-Px w erytrocytach obniżyła się po ADR u zwierząt
poddanych Px. Zmiany aktywności GSH-Px w eytrocytach po usunięciu szyszynki były słabiej wyrażone w porównaniu z aktywnością
GSH-Px w surowicy. Melatonina nie zmieniła aktywności peroksydaz po ADR. Wnioski: Melatonina w dawce farmakologicznej nie wpłynęła na aktywność peroksydaz zarówno u zwierząt nietkniętych, jak i po usunięciu
szyszynki. Deficyt endogennej produkcji melatoniny może odgrywać rolę w hamowaniu aktywności peroksydaz
Mental Health, Well-Being, and Psychological Flexibility in the Stressful Times of the COVID-19 Pandemic
This study investigated the relationships between selected emotional aspects of mental ill-health (depression, anxiety, and stress, DASS) and mental well-health (well-being) experienced during the COVID-19 pandemic. The theoretical model of the study was based on Martin Seligman’s positive psychology and PERMA theory and Paul Wong’s Existential Positive Psychology 2.0 Theory, which postulates that negative experiences contribute to well-being and personal growth. The static approach was complemented by exploring the mediating role of psychological flexibility (defined as acceptance and action in the current situation) in the relationship between negative emotions and well-being. The data were collected during the initial phase of the COVID-19 pandemic from 277 participants (221 women), aged M = 33.83, SD = 12.77. The results confirmed that negative emotions correlated negatively with various domains of well-being (PERM), except for accomplishment (completing tasks and fulfill daily responsibilities). Moreover, negative emotions were related to the general well-being through psychological flexibility in that higher depression, anxiety, and stress were associated with lower psychological flexibility, which decreased general well-being. Finally, negative emotions were shown to be beneficial, having an adaptive effect that allows individuals to maintain their ability to cope with the situation, reach goals, and fulfill daily duties and responsibilities despite critical, stressful situation (like the COVID-19 pandemic) that limit their psychological flexibility. This observation confirmed the positive potential of negative aspects of life postulated within Existential Positive Psychology
Developmental toxicity of N-methylaniline following prenatal oral administration in rats
Objectives: The objective of the study was to assess prenatal toxicity of N-methylaniline (NMA) administered by gavage to pregnant female rats. Material and Methods: Pregnant female rats were administered N-methylaniline in corn oil by gavage at daily doses of 0.8 mg/kg of body weight (b.w.), 4 mg/kg b.w., 20 mg/kg b.w. and 100 mg/kg b.w. from implantation (the 5th day post mating) to the day prior to the scheduled caesarean section (the 20th day of pregnancy). General behavior, body weight, food and water consumption, hematological, biochemical analyses and pathomorphological changes of the dams were recorded. Results: All the females survived until the end of the study. The test substance was toxic to pregnant females, even at the lowest of the used doses, i.e., 0.8 mg/kg b.w./day. Lower weight gain during pregnancy and significantly higher NMA-dose-dependent absolute weight of the organs were noted in the exposed females. The females from the groups exposed at doses of 20 mg/kg b.w./day and 100 mg/kg b.w./day developed anemia and showed higher concentrations of free thyroxine (FT3) and free triiodothyronine (FT4) thyroid hormones. Total protein concentration exhibited an increase in all the exposed groups of females. In the prenatal toxicity study, administration of N-methylaniline throughout the embryonic and fetal periods produced embryotoxic effects at doses ranging 4–100 mg/kg b.w./day. Conclusions: Considering the data obtained in this study, it is reasonable to assume that N-methylaniline administered orally to pregnant rats is toxic for mothers even at a low dose of 0.8 mg/kg b.w./day. However, this dose was not associated with any significant effects to their offspring. This prenatal exposure level may be considered as no-observed-adverse-effect level (NOAEL) for the progeny and a dose of 4 mg/kg b.w./day as the lowest-observed-adverse-effect level (LOAEL) for the progeny
urinary metabolomics study of workers exposed to hexavalent chromium
Exposure to hexavalent chromium Cr(VI) may occur in several occupational activities, placing workers in many industries at risk for potential related health outcomes. Untargeted metabolomics was applied to investigate changes in metabolic pathways in response to Cr(VI) exposure. We obtained our data from a study population of 220 male workers with exposure to Cr(VI) and 102 male controls from Belgium, Finland, Poland, Portugal and the Netherlands within the HBM4EU Chromates Study. Urinary metabolite profiles were determined using liquid chromatography mass spectrometry, and differences between post-shift exposed workers and controls were analyzed using principal component analysis. Based on the first two principal components, we observed clustering by industrial chromate application, such as welding, chrome plating, and surface treatment, distinct from controls and not explained by smoking status or alcohol use. The changes in the abundancy of excreted metabolites observed in workers reflect fatty acid and monoamine neurotransmitter metabolism, oxidative modifications of amino acid residues, the excessive formation of abnormal amino acid metabolites and changes in steroid and thyrotropin-releasing hormones. The observed responses could also have resulted from work-related factors other than Cr(VI). Further targeted metabolomics studies are needed to better understand the observed modifications and further explore the suitability of urinary metabolites as early indicators of adverse effects associated with exposure to Cr(VI).publishersversionpublishe
Relationship between intensity of night shift work and antioxidant status in blood of nurses
Toxic effect in the lungs of rats after inhalation exposure to benzalkonium chloride
Background: Benzalkonium chloride (BAC) is a quaternary ammonium compound (QAC) toxic to microorganisms. Inhalation is one of the major possible routes of human exposure to BAC. Materials and Methods: Experiments were performed on female Wistar rats. The rats were exposed to aerosol of BAC water solution at the target concentration of 0 (control group) and 35 mg/m3 for 5 days (6 h/day) and, after a 2-week interval, the animals were challenged (day 21) with BAC aerosol at the target concentration of 0 (control group) and 35 mg/m3 for 6 h. Results: Compared to the controls, the animals exposed to BAC aerosol were characterized by lower food intake and their body weight was significantly smaller. As regards BAC-exposed group, a significant increase was noted in relative lung mass, total protein concentration, and MIP-2 in BALF both directly after the termination of the exposure and 18 h afterwards. Significantly higher IL-6 and IgE concentrations in BALF and a decrease in the CC16 concentration in BALF were found in the exposed group immediately after the exposure. The leukocyte count in BALF was significantly higher in the animals exposed to BAC aerosol compared to the controls. In the lungs of rats exposed to BAC the following effects were observed: minimal perivascular, interstitial edema, focal aggregates of alveolar macrophages, interstitial mononuclear cell infiltrations, thickened alveolar septa and marginal lipoproteinosis. Conclusion: Inhalation of BAC induced a strong inflammatory response and a damage to the blood-air barrier. Reduced concentrations of CC16, which is an immunosuppressive and anti-inflammatory protein, in combination with increased IgE concentrations in BALF may be indicative of the immuno-inflammatory response in the animals exposed to BAC aerosol by inhalation. Histopathological examinations of tissue samples from the BAC-exposed rats revealed a number of pathological changes found only in the lungs
The distribution and excretion of 1-Methylnaphthalene in rats exposed to 1-Methylnaphthalene by inhalation
Objectives
1-Methylnaphthalene (1-MN) is a constituent of polycyclic aromatic hydrocarbons, the chemicals that have
become ubiquitous in the environment as result of natural and industrial process. This paper reports a study on the distribution
and excretion of 1-MN in rats after single and repeated inhalation exposure to 1-MN vapor.
Material and Methods
Male Wistar rats were exposed to 1-MN vapor at nominal concentrations of 50 mg/m 3 or 200 mg/m 3 in the dynamic inhalation
chambers (TSE Systems Head Nose Only Exposure) for 6 h (single exposure) or 5 days (6 h/day, repeated exposure).
Blood, urine and tissue samples were collected during and after the exposure. Blood, urine and tissue concentrations
of 1-MN were estimated by gas chromatography using the headspace technique.
Results
The elimination of 1-MN from
blood followed an open 2-compartment model. The concentration in rat tissues was dependent on the magnitude and time
of exposure. After repeated exposure, the concentration 1-MN in tissue decreased in comparison to single exposure. The
elimination of 1-MN with urine after single and repeated exposure to 1-MN occurred mainly in the samples collected during
the first day of collection.
Conclusions
1-Methylnaphthalene was rapidly eliminated from the blood and tissues of animals
exposed by inhalation to 1-MN. In repeated exposure, there was probably a significant increase of 1-MN metabolism
in rats exposed to low and high 1-MN doses. Under conditions of repeated 1-MN exposure, no significant systemic 1-MN
accumulation could be observed. Int J Occup Med Environ Health 2018;31(6):763–77
Health risk in road transport workers. Part I. Occupational exposure to chemicals, biomarkers of effect
Motor vehicle emissions constitute a mixture of different chemicals: volatile organic solvents, polycyclic aromatic hydrocarbons, heavy metals, isocyanates, etc. Drivers working in car cabins are exposed to chemicals deriving from incomplete combustion of fuels, exhaust emissions from working engines and fuel evaporation. Concentrations of these substances are rather low and do not exceed the applicable hygiene standards, but some of them pose, or are suspected to pose, carcinogenic risk. The interaction of chemical substances with human cells and tissues can lead to a number of modifications of metabolic pathways at a cellular level. The first biological mechanism of metabolic modulation is an inflammatory state and oxidative stress generation. The aim of this review is to analyze biomarkers of effect and to assess the hazard of occupational exposure of drivers. Int J Occup Med Environ Health. 2019;32(3):267–8
Immunostimulation using bacterial antigens – mechanism ofaction and clinical practice inviral respiratory tract infections
Recurrent respiratory tract infections constitute a significant problem in the practice of a general practitioner and
paediatrician. Antibiotic resistance of bacterial strains, which has been growing for years, prompts the search for alternative
ways of combating pathogens. One of them is the usage of preparations based on cell lysis of various bacterial strains.
Bacterial lysates have been available in Europe for many years. In preclinical trials, they are characterised by the capability
of reducing infections caused by bacteria and viruses that are not the components of the preparations. A range of clinical
trials have demonstrated their usefulness in reducing the frequency of seasonal respiratory tract infections and antibiotic use. Moreover, patients with chronic obstructive pulmonary disease gain an additional advantage in the form of the reduction
of the risk of hospitalization due to disease exacerbations and a positive influence on the survival curve. The action of bacterial
lysates is based on oral immunostimulation of gut-associated lymphoid tissue, which results in increased antibody production.
Moreover, they activate a range of mucosal mechanisms of non-specific immunity, mainly by enhancing the activity of TLR-dependent mechanisms. The efficacy of this group of drugs has been confirmed in a range of clinical trials, systematic
reviews and meta-analyses. Recent studies also indicate their immunoregulatory potential, suggesting that they might be
used in the future in preventing allergies, asthma and autoimmune diseases. To conclude, physicians (paediatricians,
laryngologists, pulmonologists) should consider reducing the use of antibiotics in their daily practice. Instead, they should
offer preparations that promote the immune system, thus controlling infections in a better way
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