ABSTRACT
INTRODUCTION: Early detection of melanoma and optimal referral to the specialist starts in primary care. Medical education is usually deficient in training general physicians in early detection and risk management for most skin malignancies. A three-point dermoscopy checklist is used as a screening tool for differentiating malignant and benign pigmented lesions in non-expert clinicians using dermoscopy. OBJECTIVES: To evaluate the impact of brief medical training on the three-point dermoscopy algorithm in third-year medical students new to dermatology and to determine the levels of sensitivity and specificity to differentiate malignant and benign pigmented lesions. METHODS: Optional dermoscopy lecture for third-year medical students new to dermatology in the context of general medical semiology courses, with case discussion and evaluation of 50 dermoscopy cases (25 benign and 25 malignant). Students were asked to classify malignant versus benign pathology based on the three-point dermoscopy algorithm discussed. Sensitivity, specificity, and predictive values were calculated according to the students' responses. RESULTS: Sixty-five students provided 3250 responses. Malignant pathology was misclassified as benign in 154 responses, while benign pathology was misclassified as malignant in 668 responses. Sensitivity and specificity for differentiating malignant lesions were 89.70% and 61.99%, respectively. Moderate interobserver agreement was found (Kappa value = 0.50; [CI: 0.47-0.54]). CONCLUSION: When evaluating melanocytic lesions, the focus of primary healthcare and general medical education should emphasize the correct determination of malignant or benign pathology. Teaching the three-point dermoscopy rule to medical students new to dermatology yields satisfactory levels of sensitivity and specificity, comparable to general physicians.
ABSTRACT
Due to the number of polyphenols with multiple biological activities, propolis has high potential to be used as an active agent in food protective films. Therefore, this study aimed to develop and characterize a sodium alginate film with ethanolic extract of propolis (EEP) for its potential use as protective active packaging against filamentous fungi in ripened cheese. Three different concentrations of EEP were analyzed: 0, 5 and 10% w/v. The films obtained were characterized, assessing thermal and physicochemical properties, as well as the concentration of polyphenols in the EEP and antifungal activity of the active films. The incorporation of EEP in the films generated thermal stability with respect to the loss of mass. Total color values (ΔE) of the films were affected by the incorporation of the different concentrations of EEP, showing a decrease in luminosity (L*) of the films, while the chromatic parameters a* and b* increased in direct proportion to the EEP concentration. Antifungal activity was observed with a fungistatic mode of action, stopping the growth of the fungus in cheeses without development of filamentous molds, thus increasing the shelf life of the ripened cheese under the analytical conditions, over 30 days at room temperature. Overall, EEP can be used to prevent growth and proliferation of spoilage microorganisms in cheese.
ABSTRACT
In this study, we developed gelatin-based films for active packaging with the ability to inhibit E. coli. We created these novel biodegradable gelatin-based films with a nisin-EDTA mix. FT-IR, TGA, and SEM analysis showed that nisin interacted with the gelatin by modifying its thermal stability and morphology. The use of nisin (2,500 IU/mL) with concentrations of Na-EDTA (1.052 M stock solution) distributed in the polymer matrix generated a significant decrease in the growth of E. coli when compared to the control. In freshly made films (t0), the growth of E. coli ATCC 25922 was reduced by approximately 3 logarithmic cycles. Two weeks after the films were made, a reduction in antimicrobial activity was observed in approximately 1, 1 and 3 logarithmic cycles of the films with 5%, 10% and 20% of the compound (nisin/Na-EDTA) distributed in the polymer matrix, respectively. This evidences an antimicrobial effect over time. Also, biodegradation tests showed that the films were completely degraded after 10 days. With all these results, an active and biodegradable packaging was successfully obtained to be potentially applied in perishable foods. These biodegradable, gelatin-based films are a versatile active packaging option. Further research on the barrier properties of these films is needed.