Antimicrobial metabolites produced by endophytic fungi associated with the leaves of Vochysia divergens.

Investigation of the endophytic fungi Nigrospora sphaerica, Nigrospora oryzae, and Pseudofusicoccum stromaticum MeOH fractions isolated from the leaves of Vochysia divergens, a medicinal species from the Brazilian Pantanal, led to the identification of five compounds, namely a new compound (1E,8Z)-10,11-dihydroxy-5,5,8-trimethyl-4-oxocycloundeca-1,8-diene-1-carbaldehyde (1) and four known compounds: 5-methylmellein (2), sclerone (3), daldinone A (4), and lasiodiplodin (5). All compounds were identified using spectroscopic methods, and 1 was corroborated with mass spectrometry, while the known compounds were compared with data in the literature. The relative configuration of compound 1 was determined based on theoretical conformational studies as well as the J experimental values between the hydroxymethyne hydrogens. The antimicrobial activity of the compounds was evaluated. Promising results were obtained for compounds 2, 4, and 5 since they inhibited the bacterium Pseudomonas aeruginosa, an opportunistic pathogen, suggesting the potential of these microorganisms as a source of new antibacterial agents.

Immunohistochemical expression of cyclin D1, p16Ink4a, p21WAF1, and Ki-67 correlates with the severity of cervical neoplasia.

High-risk human papillomaviruses are closely associated with cervical cancer and its precursor lesions through interactions between the E6 and E7 oncoproteins and the cell-cycle regulatory proteins, such as p53 and pRb, respectively. As other molecules involved in the cell-cycle control seem to be important for human papillomavirus (HPV)-mediated cervical carcinogenesis, we have analyzed the expression of p53, p21, p16, cyclin D1, and Ki-67 and the presence of HPV (HPV pool and HPV-16) by immunohistochemical studies using tissue microarray in low squamous intraepithelial lesions (n=50), high squamous intraepithelial lesions (n=98), and cervical carcinoma (n=18). We have found a significant increase in the expression of p16 and p21 (P<0.001) from low- to high-grade lesions and cancer. In contrast, cyclin D1 expression showed a significant decrease in more severe lesions (P<0.001). p16, Ki-67, p21, and p53 positivity increased with the cell-layer level and the lesion severity, with stronger correlations being observed for p16 and Ki-67. High positivity for HPV pool (96.3%) and HPV-16 (77.5%) immunostaining was detected in all cases, with an association between p16 and cyclin D1 expression and HPV-16 infection. Our tissue microarray results corroborate the usefulness of the immunohistochemical assessment of cell-cycle biomarkers in distinguishing different groups of precursor lesions of the cervix and cervical carcinoma.