Enhancing sensitivity towards electrochemical miRNA detection using an affordable paper-based strategy.

In the era of liquid biopsy, microRNAs emerge as promising candidates for the early diagnosis and prognosis of cancer, offering valuable insights into the disease's development. Among all the existing analytical approaches, even if traditional approaches such as the nucleic acid amplification ones have the advantages to be highly sensitive, they cannot be used at the point-of-care, while sensors might be poorly sensitive despite their portability. In order to improve the analytical performance of existing electroanalytical systems, we demonstrate how a simple chromatographic paper-based disk might be useful to rationally improve the sensitivity, depending on the number of preconcentration cycles. A paper-based electrochemical platform for miRNA detection has been developed by modifying a paper-based electrode with a methylene blue (MB)-modified single-stranded sequence (ssDNA) complementary to the chosen miRNA, namely miR-224 that is associated with lung cancer. A detection limit of ca. 0.6 nM has been obtained in spiked human serum samples. To further enhance the sensitivity, an external chromatographic wax-patterned paper-based disk has been adopted to preconcentrate the sample, and this has been demonstrated both in standard and in serum solutions. For each solution, three miR-224 levels have been preconcentrated, obtaining a satisfactory lowering detection limit of ca. 50 pM using a simple and sustainable procedure. This approach opens wide possibilities in the field of analytical and bioanalytical chemistry, being useful not only for electrochemistry but also for other architectures of detection and transduction.

Conservative management of primary malignant melanoma of the bladder: a case report.

BACKGROUND: Primary malignant melanoma (PMM) of the bladder represents a very rare clinic-pathologic entity. Given the rarity of the disease, the best treatment option is not well recognized. CASE PRESENTATION: We describe a case of neoplasm of the bladder in a 74 years-old Caucasian man presenting with massive hematuria. Based on clinical, instrumental and histological findings a diagnosis of PMM was made. The patient underwent trans urethral resection of bladder tumor plus intravesical Bacillus Calmette-Guérin. CONCLUSIONS: To make a correct diagnosis, clinical history, endoscopic evaluation, histopathological examination and immunohistochemistry, are necessary. Multidisciplinary evaluation is required to discriminate primary from metastatic malignant melanoma.

Mel e açúcar mascavo na cicatrização de feridas / Honey and brown sugar in wounds healing

O estudo teve como objetivo comparar a eficácia do mel e do açúcar mascavo na cicatrização de feridas induzidas cirurgicamente na pele de cobaias, para avaliar o tempo de cicatrização, as variações macroscópicas e microscópicas do tecido cicatricial, a contração das feridas e o grau de contaminação. Quinze cobaias da raça Abissínia, machos inteiros, de seis meses de idade e pesando entre 500 a 850 gramas, foram divididas em três grupos com cinco animais cada, nos quais foram induzidas, cirurgicamente, três feridas em cada animal com dimensão de 1,5cm² e distância entre elas de 1,5cm, na região dorsal. A ferida F1 foi tratada diariamente com mel, a ferida F2 com solução salina 0,9% (controle) e a ferida F3 com o açúcar mascavo. A eutanásia foi realizada no Grupo 1 ao sétimo dia após a cirurgia, no Grupo 2 ao décimo quarto dia e no Grupo 3 no vigésimo primeiro dia após a cirurgia, sendo as biópsias encaminhadas para avaliação histopatológica. Foram também realizados swabs das feridas em todos os grupos no terceiro e sétimo dias após a cirurgia e as amostras enviadas para a cultura e isolamento bacteriano. Concluiu-se que as feridas tratadas com o mel cicatrizaram mais rápido em relação às tratadas com o açúcar mascavo, demonstrando a maior propriedade cicatrizante do mel em relação ao açúcar mascavo.

The study aimed to compare the effectiveness of honey and brown sugar in wounds healing induced in the skin of guinea pigs, to evaluate the healing time, microscopic and macroscopic healing variations, wound contraction and contamination degree. Fifteen guinea pigs, Abyssinia breed, males, six months of age and weighing between 500 to 850 grams, were divided in three groups with five animals each. Three wounds were promoted in each animal, surgical, with 1.5cm² and 1.5cm between them, in the dorsal region. The F1 was treated, daily, with honey, F2 with saline solution 0,9% (control) and F3 with brown sugar. Euthanasia was performed in Group 1 on the seventh day after the surgery, Group 2 on the fourteenth day and the Group 3 on the twenty-first day after the surgery and the biopsies sent to histopathological evaluation. Wounds swabs were made in all groups on the third and seventh days after the surgery and the samples sent for culture and bacterial isolation. The wounds treated with honey healed faster than treated with brown sugar.