Atrophy and Inflammatory Changes in Salivary Glands Induced by Oxidative Stress after Exposure to Drugs and Other Chemical Substances: A Systematic Review.

Background and Objectives: Oxidative stress is involved in the alterations at the level of salivary glands, being the cause of oral pathologies like xerostomia, periodontitis, gingivitis, leucoplakia, and cancer. It is known that antioxidants can reverse changes induced by drugs or other chemicals in some organs, but the question is whether these substances can reduce or revert the effects of oxidative stress at the salivary gland level. Our aim was to find histopathological data at the level of salivary glands supporting the hypothesis of the reversal of oxidative stress-induced changes after the treatment with substances with antioxidant effect. Materials and Methods: A systematic search was conducted in PubMed, Science Direct, and Springer databases, including research articles on oxidative stress histological aspects and oxidative stress biomarkers induced by drugs or other chemicals on salivary glands. Results: Out of 1756 articles, 25 articles were selected with data on tissue homogenate used for biochemical analysis of oxidative and antioxidative markers, along with routine hematoxylin eosin (HE) and immunohistochemical analysis used for histopathological and immunohistochemical diagnosis. Drugs (antineoplastic drugs, antibiotics, and analgesics), alcohol, heavy metals, and fluoride can cause oxidative stress, resulting in morphological changes in different tissues, including in salivary glands. There are many antioxidants but only a few were evaluated regarding the effects on salivary glands in animal studies, such as hesperidin and selenium, which can reverse the damage induced by cyclophosphamide; 10-dehydrogingerdione (10-DHGD), a compound extracted from ginger, which has a protective effect against the oxidative stress and apoptosis induced by tramadol; and glycyrrhizic acid, which may repair the injuries incurred after the administration of sodium nitrite. Conclusions: Substances such as hesperidin, selenium, 10-dehydrogingerdione, and glycyrrhizic acid are antioxidants with proven restorative effects on salivary glands for the damage induced by oxidative stress after exposure to drugs and other chemical substances; however, demonstrating their similar effects in human salivary glands is challenging.

Circulating Biomarkers for Laboratory Diagnostics of Atherosclerosis-Literature Review.

Atherosclerosis is still considered a disease burden with long-term damaging processes towards the cardiovascular system. Evaluation of atherosclerotic stages requires the use of independent markers such as those already considered traditional, that remain the main therapeutic target for patients with atherosclerosis, together with emerging biomarkers. The challenge is finding models of predictive markers that are particularly tailored to detect and evaluate the evolution of incipient vascular lesions. Important advances have been made in this field, resulting in a more comprehensible and stronger linkage between the lipidic profile and the continuous inflammatory process. In this paper, we analysed the most recent data from the literature studying the molecular mechanisms of biomarkers and their involvement in the cascade of events that occur in the pathophysiology of atherosclerosis.

Impact of fatigue in patients with chronic obstructive pulmonary disease: results from an exploratory study.

INTRODUCTION: Fatigue, which is also present in the healthy population, is a common but understudied symptom in chronic obstructive pulmonary disease (COPD). We hypothesized that clinically significant fatigue is also frequent in COPD and can be associated with an increased disease burden. METHODS: An exploratory analysis derived from an ongoing cross-sectional study was carried out to evaluate levels of fatigue and impact on health-related quality of life/health status in patients with COPD (COPD group; n = 20) and healthy subjects (control group; n = 5). Health-related quality of life was measured using the Short Form Health Survey 36 (SF-36), health status with the Clinical COPD Questionnaire (CCQ), and airways obstruction with postbronchodilator forced expiratory volume in 1 s (FEV1 %predicted). Fatigue was measured with the vitality score of the SF-36, its clinical significance being defined by values of 50 or less. Fatigue was also measured using the Functional Assessment of Chronic Illness Therapy scale for fatigue (FACIT-F). RESULTS: Vitality scores were significantly worse in the COPD group (45.60 versus 76.25; p = 0.004). FACIT-F scores were significantly lower in the COPD group versus the control group (74.5 versus 95.0; p = 0.03). Clinically significant fatigue was detected in 60% of the COPD group, and was associated with a worse FEV1 %predicted (47.71 versus 65.82%; p = 0.016), worse symptoms burden (CCQ symptoms score 3.75 versus 2.43; p = 0.019), and worse overall health status (CCQ total score 3.30 versus 2.11; p = 0.011). Its link with systemic inflammation remains to be clarified further. CONCLUSIONS: Clinically significant fatigue is common among patients with COPD and is associated with an increased disease burden. It should therefore be integrated as a measure of disease prognosis and control in patients with COPD.

Rad51 overexpression and resistance to genotoxic agents. A study in the fission yeast Schizosaccharomyces pombe.

BACKGROUND: Many cancer cell lines have been found to overexpress the recombinase Rad51. The overexpression is associated with increased invasive potential and resistance to DNA-damaging therapeutic agents. This has been attributed to an increased capacity of cells overexpressing Rad51 to repair DNA lesions or to a genetic stabilization of the genome. AIM: As the explanations are somewhat controversial, we attempted to reproduce overexpression in the unicellular eukaryote Schizosaccharomyces pombe to have a simpler tool to study the problem of Rad51 overexpression and its induced resistance to DNA-damaging agents. METHODS: We used the nmt1 promoter inserted upstream of rad51 gene to induce its overexpression and studied the phenotype of the transformed strain, especially its sensitivity to camptothecin and hydroxyurea. RESULTS: We found that overexpression induced sensitivity to the two drugs even when it was associated with the deletion of a recombination mediator rad22/rad52 gene. However, when overexpression was associated with the deletion of the helicase-encoding fbh1 gene, the sensitivity to camptothecin was diminished.

Rad52 protein function study by fluorescence tagging.

Rad52 protein plays a significant role in DNA lesions repair by homologous recombination in eukariotic cells. Human Rad52 function somewhat overlaps with BRCA2 and has a role in cell survival in the absence of BRCA1-BRCA2 mediated recombination. Additional Rad52 function analysis and intracellular localization studies are probably necessary. We present a method for Rad22 protein tagging, a Schizosaccharomyces pombe Rad52 homologue, by Crerecombinase-mediated cassette exchange (RMCE) using the versatile pAW8 plasmid. Rad22 protein was C-termini yEGFP tagged; the resulting strain was analyzed by fluorescence microscopy. The yEGFP signal was observed (Rad22 foci) for 7.5 microM camptothecin, 0.005% methyl methanesulfonate, and 4 mM hydroxyurea treated cells. The RMCE method was efficient, and the presence of tagged Rad22 protein was confirmed by Western-Blot and fluorescence microscopy.

A new method for the quantification of superoxide dismutase mimics with an allopurinol-xanthine oxidase-lucigenin enhanced system.

Allopurinol is a prodrug converted to oxypurinol by xanthine oxidase, a process followed by an efficient enzyme inhibition. Using a lucigenin-enhanced chemiluminescence method, we found that, under alkaline conditions, superoxide radicals are produced in large amounts in the first step of the interaction between the enzyme and the inhibitor. A comparison between lucigenin and cytochrome c as final detectors revealed that only the chemiluminescence technique is able to detect the superoxide anions from allopurinol oxidation. The allopurinol-xanthine oxidase-lucigenin system can be used for the quantification of various free-radical scavengers, in particular superoxide dismutase mimics. Three manganese compounds from different structural classes [manganese(II) chloride, manganese N,N'-bis(salicylidiene)ethylenediamine chloride, and manganese(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin] were compared at five concentrations (0.01, 0.1, 1, 10, and 100 µM). The method is fast, 16 times more sensitive than the cytochrome c assay at pH 10.1 and could be used for in vivo investigations avoiding the lucigenin redox cycle. If the concentrations of the reagents are increased and Tween 20 is added, the method is also operative at pH 7.4.

Method for protein tagging in Schizosaccharomyces pombe.

Tagging is a useful method for the investigation of proteins. It allows the localization of the proteins in the cell, their purification in order to investigate their function and the determination of their expression. The aim of the present study was to tag the Rad32 protein of fission yeast (which is the homologue of Mre11 protein from humans) at its N-terminus. Rad32p as well as Mre11p are involved in the repair of DNA double strand breaks and in the DNA damage checkpoint. We carried out this tagging using the Cre-loxp recombination system. In a first step, a 2 kb DNA fragment was integrated upstream of the initiating codon of rad32 gene. This fragment encoded the TAP-tag (tandem affinity purification), a loxp site, a selectable marker (sup3-5), an exogenous promoter (nmt1) and a second loxp site, in this sequence. Following transformation of this DNA fragment into S. pombe cells, rad32 was under the control of the artificial promotor, which allows a controlled expression of the gene by thiamine. In a second step, the cells were transformed with a plasmid coding for Cre recombinase, which catalyses the excision of the DNA sequence between the two loxp sites, removing the marker and the artificial promotor. Thus the tag became attached to the rad32 gene upstream of the ATG, placing the gene under the control of its native promotor. The strain thus obtained will be subsequently used for evidencing the tagged protein by Western blotting and then for its purification in order to investigate its function.

[Deletion of two genes from the genome of fission yeast Schizosaccharomyces pombe. Genetic manipulation and phenotype study]. / Deletia a doua gene din genomul drojdiei fisipare Schizosaccharomyces pombe. Manipulare genetica si studiu fenotipic.

The aim of this study was to delete two genes from the genome of the fission yeast S. pombe in order to search for their functions in the cell. These genes are SPAC869.02c (MRI) and SPBC21C3.19 (MR2) and previous studies reported their significant induction after gamma irradiation. We carried out the deletions of the two genes and we replaced them with the selection marker ura4. Among the phenotype characteristics we tested the viability, the sexual behaviour and the radiosensitivity to ultraviolet and gamma irradiation. Our results indicate that MR1-deleted strain is sensitive to both UV and gamma irradiation, while the survival of the irradiated MR2-deleted strain doesn't appear to be influenced by the deletion. This suggests an involvement of MR1 gene in the adaptive response triggered by these types of genotoxic aggression. The comparison of MR1-d and MR2-d with the double deleted strains containing the deletion of MR1 or MR2 combined with the deletion of sty1 or rad3 genes led to a surprising result: the double mutants MR1-d sty1-d and MR1-d rad3-d were more resistant to both UV and gamma irradiation than the simple deleted strains sty1-d and rad3-d, respectively. This suggests a possible contribution of MR1 gene to the lethal process taking place in irradiated cells.