Background and Objectives: Multiple evaluations of oxidative stress in individuals with substance use disorder show elevated levels compared to non-substance-abusing individuals. Information concerning antioxidant defense mechanisms in relation to alcohol and opioid dependence is variable and sometimes contradictory. The objective of the present investigation was to identify and compare several antioxidants in plasma during distinct phases of alcohol and opioid dependency (intoxication and withdrawal). Materials and Methods: This case study focuses on individuals with opioid and alcohol addiction. We recruited 80 participants (males aged 40 ± 10 years) and equally divided them into two categories: those with alcohol addiction and those with opioid addiction. A control group consisted of 20 healthy adults (males aged 35 ± 10 years). The spectrophotometric methods were used to quantify catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activity in plasma. Antioxidant values were analyzed between groups using pairwise Mann–Whitney tests. Results: During withdrawal from alcohol and opioids, catalase activity tends to decrease compared to intoxication. The overall activity of superoxide dismutase exhibited an increase during alcohol intoxication and withdrawal and a reduction during opioid withdrawal compared to the intoxication phase. Both alcohol and opioids reduced plasma GPx activity in withdrawal cases, although the extent of this decrease varied considerably. Conclusions: The study confirms the valuable impact of addiction on the organism’s oxidative stress and reveals various behaviors of antioxidant defense enzymes during intoxication and withdrawal phases.

The dose-dependent effects of single metals (Zn, Ni, and Cu) and their combinations at steady time-actions on the cell viability of the bacteria Shewanella xiamenensis DCB 2-1, isolated from a radionuclide-contaminated area, have been estimated. The accumulation of metals by Shewanella xiamenensis DCB 2-1 in single and multi-metal systems was assessed using the inductively coupled plasma atomic emission spectroscopy. To estimate the response of the bacteria’s antioxidant defense system, doses of 20 and 50 mg/L of single studied metals and 20 mg/L of each metal in their combinations (non-toxic doses, determined by the colony-forming viability assay) were used. Emphasis was given to catalase and superoxide dismutase since they form the primary line of defense against heavy metal action and their regulatory circuit of activity is crucial. The effect of metal ions on total thiol content, an indicator of cellular redox homeostasis, in bacterial cells was evaluated. Genome sequencing of Shewanella xiamenensis DCB 2-1 reveals genes responsible for heavy metal tolerance and detoxification, thereby improving understanding of the potential of the bacterial strain for bioremediation.

The efficiency of hybridization signal detection in a biochip is affected by the method used for test DNA preparation, such as fragmentation, amplification and fluorescent labelling. DNA fragmentation is the commonest methods used and it is recognised as a critical step in biochip analysis. Currently methods used for DNA fragmentation are based either on sonication or on the enzymatic digestion. In this study, we compared the effect of different types of enzymatic DNA fragmentations, using DNase I to generate ssDNA breaks, NEBNext dsDNA fragmentase and SaqAI restrictase, on DNA labelling. DNA from different Desulfovibrio species was used as a substrate for these enzymes. Of the methods used, DNA fragmented by NEBNext dsDNA Fragmentase digestion was subsequently labelled with the greatest efficiency. As a result of this, the use of this enzyme to fragment target DNA increases the sensitivity of biochip-based detection significantly, and this is an important consideration when determining the presence of targeted DNA in ecological and medical samples.