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•An electrochemical biosensor with the COX enzyme was developed.•The sensor allowed us to study both enzyme’s processes that relate to its functions and propose a mechanism•Throughout ...the biosensor the enzyme‘s kinetic constants were. Km = 4.33 × 10-6, kcat = 5.69 s−1, Vm = 40.2 μ mol L-1.•The inhibition in % of the enzyme by commercial Non-Steroidal Anti-inflammatory drugs was obtained by voltammetry and EPR.
In this research, we developed a biosensor to analyze the anti-inflammatory properties of non-steroidal anti-inflammatory drugs (NSAIDs) and potential candidate molecules. The chemical interaction between commercial NSAIDs and their target, the cyclooxygenase-2 enzyme (COX), was studied using electrochemical techniques and electronic paramagnetic resonance (EPR). The modified electrode, COX@GCE biosensor, presented two main reduction processes. We observed that the first one involves one electron and one proton related to tyrosyl radical reduction to tyrosine, and the second comprises a one-electron reduction from the Fe (IV) to Fe (III) species present in the enzyme’s active site, which in the presence of hydrogen peroxide results in a catalytical process. Based on these results, an electrochemical mechanism of the COX enzyme is proposed. Additionally, the quantitative inhibitory interaction mechanisms of six commercial NSAIDs were studied using this biosensor. The NSAIDs acetylsalicylic acid, dipyrone, and ibuprofen presented the higher COX inhibitory percentual, being, therefore, the most effective NSAIDs among the studied group. Salicylic acid also presented a significant inhibition capability in both electrochemical and EPR studies. The effect of some NSAIDs, e.g., dipyrone and acetaminophen, can be explained by the redox inhibition hypothesis and can be related to the direct interaction and inactivation of the iron present in the enzyme’s active site. Ibuprofen and naproxen presented irreversible COX inhibition. Despite that, the EPR shows that these drugs have relatively weak interactions with the COX active site, suggesting they should interact with the external structures resulting in the inhibition of its activity. Finally, the developed enzymatic sensor presented a high potential to study the anti-inflammatory properties of well-known drugs and can be a useful tool in the development of new NSAIDs, in a more efficient way, therefore presenting high applicability in drug development, pharmaceutical, and biomedical applications in both academia and industry.
We performed an anatomic study on 20 fresh lower limbs. Resin was injected in the popliteal artery. Medial sural artery perforator flaps were sculptured according to anatomic markings. On average, ...length of flaps was 12.9 cm, width was 7.9 cm; all 38 perforators were musculocutaneous: 1 perforator was always found (on average, 1.9 per flap). All perforators gathered between 7 and 18 cm from the popliteal crease; 34.2% of perforators arose on the midline of the medial head of gastrocnemius muscle; before entering the fascia, the perforator artery diameter was on average 0.5 mm. Two configurations of the intramuscular course of perforators were found. Sixty-six percent of perforators originated from the lateral branch of the medial sural artery, 34% from the medial one. These results improve the anatomic knowledge of the medial posterior calf region and allow us to describe a convenient plan to make flap sculpturing easier.
•The immunosuppressive leflunomide anodic behavior at glassy carbon and boron doped diamond electrodes.•Anodic and cathodic electroactivation of BDD lead to different electrochemical answer of ...leflunomide.•Leflunomide redox mechanism at GCE and a-BDDE.
The electrochemical oxidation of leflunomide (LFM), a pharmaceutical compound used for the treatment of rheumatoid arthritis, was studied at glassy carbon and boron doped diamond electrodes by cyclic, differential pulse, and square wave voltammetry. At glassy carbon electrode, the oxidation of LFM is an irreversible, diffusion-controlled one electron one proton transfer reaction, and occurs at the nitrogen atom of the p-toluidil moiety, followed by nucleophilic addition of water and formation of a N-acetylated imine derivative, becoming pH-independent for pH>10.0. For LFM the value of pKa∼11 was determined, and confirmed by UV–Vis. The oxidation behaviour of LFM at boron-doped diamond electrode is a complex, electrode activation dependent mechanism. At anodic pre-treated boron-doped diamond electrode hydroxyl radicals are generated at high positive potentials, close to the water discharge, and one oxidation peak occurred. LFM interacts with hydroxyl radicals adsorbed at the electrode surface, as a hydroxyl radical scavenger, and the reaction product is electroactive and oxidized at high potential. At cathodic pre-treated boron-doped diamond electrode, no oxidation reaction occurs. An electrochemical oxidation mechanism for LFM was proposed.
The authors performed an anatomic study on 16 thighs of 11 fresh white cadavers at the Ludwig-Maximilian University of Munchen, Germany. They analyzed the anatomic pattern and caliber of both the ...lateral circumflex femoral arterial system and the perforators nourishing the anterolateral thigh flap. They found regularly a majority of musculocutaneous perforators, mainly in the central third of the thigh, arising from the descending branch of the lateral circumflex femoral artery. Despite the small number of cadavers, they identified several differences in the anatomy of the lateral circumflex femoral arterial system. These variabilities, especially regarding the descending branch and its perforators, could have clinical importance. They also suggest new dissection studies by comparing white and oriental anatomy. Their aim is to establish whether any difference in the variability of the lateral circumflex femoral arterial system could increase the popularity, currently greater in Eastern Europe, of the anterolateral thigh flap.
Objective: The article presents the results of a pilot study performed to evaluate the efficacy of polydeoxyribonucleotides (PDRNs) in shortening the healing times of autologous skin graft donor ...sites. Research design, methods: Two groups of patients were studied, the PDRN group (n = 20) and a control group (n = 20). In the control group dressings were performed with non-adherent gauzes and bulky gauzes with cloramine solution, whereas in the PDRN group a PDRN ointment was spread under the same medication as the controls.
Results: In the PDRN group, dressing procedures were not painful (whereas in the controls they often were), re-epithelialisation occurred earlier (12.5 vs 24.45 days) and there were no infections (9 in the controls).
Conclusions: Results are encouraging for the use of PDRNs in shortening the healing times of autologous skin graft donor sites, although further studies are necessary to obtain clinically relevant results.
A case is presented in which an aesthetic breast augmentation by fat injection led a young woman to a life-threatening sepsis due to bilateral mammary abscesses. Immediate and late complications of ...this procedure are considered; infection is the frightful complication that can lead to septic shock, affecting survival, aesthetic outcome, and reconstruction possibilities of the patient's breasts.
Background. Calcinosis cutis, a disease characterized by the presence of calcium deposits in the skin, is classified into four types according to etiology: dystrophic, metastatic, iatrogenic and ...idiopathic. The dystrophic form is the most common while the idiopathic one is the rarest, but specific incidence and frequency data are not available in scientific literature.
Objective. Calcinosis cutis circumscripta is a very rare form of idiopathic calcinosis cutis arising in the second half of life. It typically involves the extremities and is associated with prior trauma and scleroderma. We dealt with a very rare form of calcinosis cutis circumscripta in a healthy patient, for whom surgical excision revealed to be an effective and successful treatment.
Methods and materials. We present the case of a 46‐year‐old woman affected by idiopathic circumscripta calcinosis cutis of the left knee, successfully treated by surgical removal.
Discussion. Medical and surgical treatment are options to cure calcinosis cutis. Medical therapy is not very effective. Surgical excision has shown to be beneficial, as it can provide a symptomatic relief. However, since calcinosis cutis limits are not always well defined a recurrence of the lesions may occur.
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