Browsing by Author "Gajić, Milan M. (55981692200)"

Background: Reactive oxygen species are involved in the pathogenesis of colorectal carcinoma. Clarification of oxidative/antioxidant specificities of different stages of colorectal carcinoma is of special importance. Aim: To determine oxidative/antioxidant status in plasma of patients with different stages of colorectal carcinoma using malondialdehyde concentration, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities and distribution of superoxide dismutase isoforms. Methods: Lipid peroxidation and antioxidant enzymes activity were estimated using spectrophotometric methods. Reverse zymography was applied for characterization of superoxide dismutase isoforms. Results: Lipid peroxidation is increased in all groups compared to the control, but without differences between different stages of colorectal carcinoma. Total superoxide dismutase activity is lower in all colorectal carcinoma groups than in control, and there is a significant increase in tumor stage IV when compared with tumor stage II. Manganese superoxide dismutase isoform is dominant in all groups and its relative activities are significantly higher than activities of a copper/zinc isoform. Total peroxidase potential reflected in catalase and glutathione peroxidase activity is increased when compared to the control, but without any significant differences between colorectal carcinoma groups. Glutathione reductase activity is lower in all colorectal carcinoma groups than in control, and a significant decrease in glutathione reductase activity was obtained between patients in tumor stage II and III compared to tumor stage IV. Conclusions: Colorectal carcinoma is characterized by increased oxidative stress and antioxidant disbalance. Progression of disease is followed by an increase in redox disbalance. © 2013 Springer Science+Business Media New York.

Background: Reactive oxygen species are involved in the pathogenesis of colorectal carcinoma. Clarification of oxidative/antioxidant specificities of different stages of colorectal carcinoma is of special importance. Aim: To determine oxidative/antioxidant status in plasma of patients with different stages of colorectal carcinoma using malondialdehyde concentration, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities and distribution of superoxide dismutase isoforms. Methods: Lipid peroxidation and antioxidant enzymes activity were estimated using spectrophotometric methods. Reverse zymography was applied for characterization of superoxide dismutase isoforms. Results: Lipid peroxidation is increased in all groups compared to the control, but without differences between different stages of colorectal carcinoma. Total superoxide dismutase activity is lower in all colorectal carcinoma groups than in control, and there is a significant increase in tumor stage IV when compared with tumor stage II. Manganese superoxide dismutase isoform is dominant in all groups and its relative activities are significantly higher than activities of a copper/zinc isoform. Total peroxidase potential reflected in catalase and glutathione peroxidase activity is increased when compared to the control, but without any significant differences between colorectal carcinoma groups. Glutathione reductase activity is lower in all colorectal carcinoma groups than in control, and a significant decrease in glutathione reductase activity was obtained between patients in tumor stage II and III compared to tumor stage IV. Conclusions: Colorectal carcinoma is characterized by increased oxidative stress and antioxidant disbalance. Progression of disease is followed by an increase in redox disbalance. © 2013 Springer Science+Business Media New York.

Purpose: Intrapatient comparison of in vivo distribution of two Ga-68-labeled somatostatin (agonist) analogues with different in vitro affinities for human somatostatin receptor (sstr) subtypes 2, 3, and 5 by determining their SUVmax values in normal liver, primary tumors, and metastases in gastroenteropancreatic (GEP) neuroendocrine tumor (NET) patients. Methods: 68Ga-DOTATATE and 68Ga-DOTATOC PET/CT studies were performed at consecutive visits in 38 GEP NET patients (1 duodenal, 18 pancreatic, 2 cecal, 12 ileal, 3 jejunal, 1 mesenteric, 1 NET in appendix) with stable disease on both occasions, with 197 days (117-311 days range) in between. Time to start of scanning after injection was identical for both studies. SUVmax for both radiopharmaceuticals in primary tumors, liver-, lymph node-, soft tissue-, and bone-metastases and in normal liver tissue were compared. Results: Overall, 225 metastases (98 liver, 67 lymph node, 43 bone, 17 soft tissue) and 18 primary GEP NETs were analyzed on both 68Ga-DOTATOC and 68Ga-DOTATATE studies. Mean SUVmax in the TATE/TOC groups were: normal liver 6.8 ± 1.7/6.9 ± 1.8, metastases in the liver 15.4 ± 9.4/17.9 ± 11.4, lymph nodes12.0 ± 9.5/15.2 ± 13.3, bones 7.5 ± 5.7/9.9 ± 8.0, soft tissues 15.3 ± 16.4/17.3 ± 18.8, primary tumor 20.4 ± 13.7/24.23 ± 20.1. Average 68Ga-DOTATOC accumulation was always higher. The differences between TATE/TOC groups were significant in primary tumors, liver-, lymph node-, and bone-metastases, but not in soft tissue-metastases. Notwithstanding these highly significant differences, considerable variability amongst patients in preferred tracer uptake was observed. Conclusions: On average, 68Ga-DOTATOC shows significantly higher uptake in GEP NET primary tumors and metastases than 68Ga-DOTATATE. However, we have also observed considerable variability in preferred peptide uptake. Optimal therapy planning would therefore require somatostatin receptor imaging with both these peptides. © The Editor(s) (if applicable) and The Author(s) 2024.