The evaluation of the oxidative stress for patients receiving neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

Hypothesis: Nowadays, rectal cancer is an important healthcare challenge that affects many thousands of people each year worldwide, being diagnosed especially after the age of 50 years. Objective: This study attempted to evaluate the oxidative stress in patients with rectal cancer. Methods and results: 30 patients from the "Prof. Dr. Al. Trestioreanu" Institute of Oncology in Bucharest were treated with neoadjuvant radiochemotherapy during 2014 and 2016 and were included in the clinical study. Blood samples were obtained in dynamics during the treatment. From the blood samples, the serum was separated and used to identify the biochemical oxidative stress parameters. Results: Regarding the determination of lipid peroxides, albumin thiols, the cuprum oxidase activity of ceruloplasmin, the values registered in the dynamic of the treatment highlighted their increase to a maximum at the treatment's endpoint due to an important oxidative stress. Regarding the serum values for total antioxidants, the results pointed out the activation of the natural protection systems, which in time were overwhelmed, due to the installed oxidative stress. Conclusion: Part of the cytotoxic effect of radiotherapy was due to the production of oxidative stress. The cell was constantly exposed to the cytotoxic action of the reactive oxygen species. The obtained results indicated the dual relation to which the tumoral cell exposed itself and the installed oxidative stress, respectively, the oxidative stress being a cause or a consequence of the malign transformation. Abbreviations: CT = computed tomography, MRI = magnetic resonance imaging, ESMO = European Society for Medical Oncology, ECOG = performance status scale.

Parameters of oxidative stress variation depending on the concentration of inorganic zinc compounds.

Zinc deficiency is a problem faced by a large number of people, a U.S. study showing that only 46% of the population aged over 71 years has the best amount of zinc in the body. Due to the very complex role of zinc deficiency in this trace, it can occur through a variety of symptoms affecting multiple body functions. Zinc was demonstrated to have the ability to neutralize free radicals protecting the body from the harmful effects of these effects, ultimately leading to atherosclerosis and cardiovascular disease derived from premature aging, the immune and immune disorders and increased risk of cancer. The purpose of the paper is to identify the role of antioxidant systems, with Zn2+ ions in the center of defense and decrease oxidative stress in dynamic interaction with malignant transformed cells.

The evaluation of non-enzymatic antioxidants effects in limiting tumor- associated oxidative stress, in a tumor rat model.

Active oxygen species are produced as a consequence of normal aerobic metabolism. Of these, free radicals are usually metabolized or inactivated in vivo by a team of antioxidants. Individual members are a trained team fighting antioxidants to prevent the generation of ROS, destroy or oxidizing potential of capture. In terms of physiological oxidative stress, induced tissue attack is minimal. A relative or absolute deficiency in the antioxidant defense may lead to increased oxidative stress and this event is associated with both the causes and consequences of diseases and cancer, included here. The aim of the study is to identify the role of antioxidant defense systems and the reduction of oxidative stress in dynamic growth and development of malignant tumors. Our in vivo study was developed and referred to carcinosarcoma carriers Wistar rats treated with non-enzymatic antioxidants: vitamin C, vitamin A, zinc salt (II), and arginine in various combinations. Treatment was initiated three weeks before tumor induction.

Pain-associated biomarkers in breast cancer.

Breast cancer represents a major public health problem, being the highest incidence neoplasia in females in Romania. The most important step in the treatment of this neoplasia is the surgical procedure; the biggest problem associated with this form of treatment in these patients is pain-related. Pain is a complex symptom with an impact on quality of life and psychology of cancer patient and can only be monitored verbally and subjectively. Consequently, the purpose of our work is to identify some biochemical parameters involved in the events cascade associated with inflammation and pain in breast cancer female patients, monitored in dynamics of anesthesia and surgical procedure. Measurements of lipid peroxides, ceruloplasmin and immune circulating complexes in mentioned dynamics have been performed. The recorded values are in concordance with the inflammatory processes and pain intensity, thus we can allege that these measurements can complete the pain-associated clinical picture in female breast cancer patients.

Involvement of reactive oxygen species in the mechanisms associated with cervical cancer specific treatment.

Cervical cancer represents a genuine health issue in Romania.The courses of treatment applied are complex, and the accompanying biochemical mechanisms are yet to be fully understood. Thus, radiotherapy, which induces reactive oxygen species, can lead to failure of treatment in hypoxic tissues,tissues which are difficult to identify due to the small quantity in which these cytotoxic species are produced. As a result, the aim of this paper is to identify the production and role of reactive oxygen species, as well as the manner of activation of endogenous antioxidant defense mechanisms in cervical cancer patients admitted to the Oncologic Institute of Bucharest. To this purpose the biochemical parameters of oxidative stress were identified in 30 patients with cervical tumour localization, prior to surgery. The results obtained have showed that a production of reactive oxygen species is identifiable in these patients, having lipids as a primary target and leading to their peroxidation. The extension of protein oxidative degradation takes place at a much lower value, as well as the activation of endogenous antioxidant defence systems, comparing to our expectations. To conclude,we consider that when the production of active oxygen metabolites takes place in small concentrations, associated with hypoxia, the signals transmitted are towards modifying the phenotype under anaerobic conditions into one activating neo vascularization, angiogenesis initiation, new cell growth and proliferation. The moment that this phase is overcome anew oxidative stress is installed, one potentially destructive for biomolecules essential to life, but also useful for further treatment, such as radiotherapy.

Monitoring the production of reactive oxygen species in experimental melanoma.

HYPOTHESIS: Melanoma is one of the most aggressive forms of skin cancer characterized by malignant proliferation of melanocytes. The role played by reactive oxygen species and free radicals in the pathology of melanoma in humans is widely accepted today. OBJECTIVE: This paper aims to characterize some types of malignant melanoma obtained experimentally by the inoculation of reference cells for the creation of models and the identification of oxidative stress markers usable for monitoring tumor growth and development. METHODS AND RESULTS: Mice C57Bl/6. Reference cell lines B16, F1, F10. Inoculation of cells was performed in the upper right flank. Tumors were characterized both anatomically and morphologically. For the biochemical characterization of the oxidative stress, tests were performed to determine lipid peroxides, total albumin thiol groups and total antioxidant response. Tumor volume was measured in dynamic. The fastest development has been observed in type B melanoma. For the F and F10 types, the curves profiles are the same. The results indicate an increase of lipid peroxidation reaction in dynamic tumor evolution, suggesting the malignant associated transformations. DISCUSSION: These data demonstrate that an alteration of the antioxidant pattern can be detected in the serum of the experimental animals with melanoma, possibly related to the disease status and progression. Our results can be useful in monitoring the tumor evolution and also to highlight the prolonged damage which actions on the normal cells, suggesting the combination of the classical treatments with an adjuvant antioxidant treatment.