<p style="text-align: justify;">Shape memory alloys are of great commercial importance from biomedical applications to smart materials. The electrochemical behavior of Cu-Al-Zn alloy in phosphate buffer without and in the presence of amino acid was investigated. Electrochemical researches were performed in a traditional three-electrode system by means of the Tafel extrapolation method. The results showed that the presence of amino acid leads to a decrease in the corrosion rate and the density (values) of the corrosion current, which indicates that the tested inhibitor is efficient.</p>
In this study, the impact of glucocorticoid, betamethasone dipropionate on enzyme activity in vitro and its effects on hematological parameters in vivo was investigated. The immobilized catalase, crucial for cell oxidative stress response via hydrogen peroxide reduction, exhibited a robust electrocatalytic response, maintaining its biological activity. The in vitro inhibition kinetics of catalase, as determined by electrocatalytic methods and expressed using Lineweaver-Burke diagrams, revealed an uncompetitive type of inhibition with altered Imax and Km in the presence of a range of betamethasone dipropionate concentrations. The in vivo experiments conducted on Rattus norvegicus demonstrated significant alterations in hematological parameters following betamethasone dipropionate administration. These changes included a decrease in erythrocyte count, an increase in hemoglobin, a reduction in mean corpuscular volume (MCV), and an elevation in mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). Notably, the leukocyte counts substantially increased. The observed hematological shifts suggest an impact of betamethasone dipropionate on the hematopoietic system, reinforcing the need for cautious corticosteroid administration. The findings underline the necessity for judicious corticosteroid treatment, acknowledging both enzymatic and systemic repercussions.
Abstract The amperometric biosensor was created using a flat sheet of the Cu-Zn-Al shape memory alloy, with a shiny surface and uniform thickness below 1 mm. The high biocompatibility and a large specific surface area for enzyme loading are evaluated. In vitro biomedical corrosion testing of samples revealed successful immobilization of catalase, which has undergone quasi-reversible electron transfer from the surface and saline solution. A catalase that had been immobilized retained its basic structure and bioactivity and demonstrated a remarkable electrocatalytic response to hydrogen peroxide reduction. The reduction of hydrogen peroxide on the catalase-modified Cu-25.38Zn-3.3Al alloy was investigated using hydrodynamic amperometry in both the absence and presence of l-cysteine and K2[B3O3F4OH] inhibitors. Catalytic reduction currents have increased as a result of the gradual increase in hydrogen peroxide concentration. The study on enzyme activity inhibition has shown a lower corrosion rate of catalase-modified bioalloy than the initial sample because inhibitor ions occupy all sites of the immobilized enzyme.
Glucocorticoids prevent or suppress the full inflammatory response to the infectious, immunological or physical agents by inhibiting early inflammatory events such as edema or cell exudation. The main effect of glucocorticoids on the inflammatory process is the inhibition or recruitment of neutrophils and monocytes. In this study, the effect of the glucocorticoid betamethasone on the hematological parameters of rats of the species Rattus norvegicus Berkenhout 1769 was examined in vivo. Betamethasone has been shown to affect the values of hematological parameters four hours after application and leads to a significant decrease in the prevalence of lymphocytes and monocytes, but also leads to a statistically significant increase in erythrocyte count, hemoglobin concentration and hematocrit values.
Aim: The chief aim of this study was monitoring of laboratory parameters of chronic kidney failure in elderly patients. Methods: All samples were taken and processed by standard methods and according to the principles of good laboratory practice. Data were collected in an organized and systematic manner in the form of a questionnaire with respect to ethical principles and as such were analyzed by statistical tests and analyses (Student's t-test, Analysis of variance-ANOVA, Pearson's and Spearman's correlation coefficients). The limit of statistical significance was set at p < 0.05. Results: Mean values of creatinine clearance and proteinuria for the total study population were: 41.30 ± 21.43 mL/min, 1.5 ± 2.3 g/L/24 h, respectively. Hematological parameters did not significantly differ from normal values. The highest frequency of comorbidities was observed in subjects aged ≥ 80 years with an average of 2.03 comorbidities per subject. Serum creatinine and urea values as well as creatinine clearance are good indicators of disease progression. Conclusion: The results of the presented research suggest that old age is a predisposing risk factor for the development of chronic kidney disease, and that in combination with comorbidities (hypertension and/or diabetes), it contributes to poor prognosis or disease progression.
Aluminium and its alloys have excellent corrosion resistance. When aluminium is exposed to the atmosphere, a thin invisible oxide Al2O3 is formed, protecting the metal from further oxidation. Compared to pure metals, alloys can have higher corrosion resistance depending on the content of certain alloying elements. Various substances such as organic or inorganic inhibitors can affect the corrosion of aluminium alloys and thus slow down the degradation of the material. In this paper, we studied the inhibitory effect of potassium dichromate on the corrosion processes of aluminium alloy. All measurements were performed in 0.5 M sodium chloride solution with the addition of different concentrations of inhibitors. The methods used were potentiodynamic polarization, cyclic voltammetry, and chronoamperometry.
Most pharmaceutical and nutritional compounds are marketed as enzyme inhibitors, and such inhibitors show their specific action in inhibiting enzymes within cells. Since their discovery, corticosteroid treatment has been one of the most used and effective treatments for various inflammatory and autoimmune disorders. Corticosteroids have anti-inflammatory and immunosuppressive effects, so it is hypothesized that these corticosteroids will have an inhibitory effect on the enzyme catalase. This study aimed to examine the effect of the corticosteroid’s betamethasone dipropionate and prednisone on catalase activity in vitro. A spectrophotometric method was used based on the reaction between hydrogen peroxide, enzymes, and corticosteroids. After incubation at 37°C with the addition of ammonium heptamolybdate, a stable complex was formed, and the absorbances were analysed. The obtained results indicate an uncompetitive type of inhibition in betamethasone dipropionate, while prednisone acts as a partial competitive agent.
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