Amperometric sensor for glutathione reductase activity determination in erythrocyte hemolysate

Electrochemical sensor for glutathione reductase based on screen-printed electrodes coated with 3,5-dinitrobenzoic acid-modified carbon nanotubes

The preparation of a hybrid nanomaterial is reported by covalently attaching 3,5-dinitrobenzoic acid groups to the surface of oxidized multi-walled carbon nanotubes using 1,6-diaminohexane as cross-linking agent. This nanomaterial, modified with the redox mediator, was used as transduction element to construct an amperometric sensor for the efficient indirect determination of glutathione reductase at a low working potential of - 0.05 V, through the oxidation of unconsumed nicotinamide adenine dinucleotide phosphate (NADPH) in the enzymatic reaction. The sensor exhibited an excellent linear response in the range 1.6 to 174 µU/µL, with high reproducibility and selectivity. The developed device was successfully validated in real samples, accurately determining the active enzyme in diluted human serum, making it a promising alternative for the determination of glutathione reductase and other related NADPH-dependent enzymes with relevance in clinical analysis.

Leydig cell number and sperm production decrease induced by chronic ametryn exposure: a negative impact on animal reproductive health

Ametryn is an herbicide used to control broadleaf and grass weeds and its acute and chronic toxicity is expected to be low. Since toxicological data on ametryn is scarce, the aim of this study was to evaluate rat reproductive toxicity. Thirty-six adult male Wistar rats (90 days) were divided into three groups: Co (control) and T1 and T2 exposed to 15 and 30 mg/kg/day of ametryn, respectively, for 56 days. Testicular analysis demonstrated that ametryn decreased sperm number per testis, daily sperm production, and Leydig cell number in both treated groups, although little perceptible morphological change has been observed in seminiferous tubule structure. Lipid peroxidation was higher in group T2, catalase activity decreased in T1 group, superoxide dismutase activity diminished, and a smaller number of sulphydryl groups of total proteins were verified in both exposed groups, suggesting oxidative stress. These results showed negative ametryn influence on the testes and can compromise animal reproductive performance and survival.

Adjusting a biochemistry course for physical education majors: A case study

The purpose of this study was to investigate and analyze the events responsible for curricular characteristics that lead to positive outcomes in university teaching using a biochemistry course taught to physical education students as a model. The research was carried out as a case study, supported by questionnaires, classroom observation, document analysis, and interviews. The overall analyses of obtained data were validated by means of triangulation protocols, which proved the following reasons for the course achievements: 1) teaching staff deeply committed to the course; 2) contents adaptation to students' careers; 3) gradual adjustment of the teaching strategies and evaluation tools; 4) valorization of formative evaluation; and 5) providing a suitable affective milieu.