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Morphological changes of a toxigenic isolate of Aspergillus parasiticus cultured in the presence of aqueous leaf and seed extracts obtained from neem, Azadirachta indica A. Juss (syn. Melia azadirachta L.), a potent inhibitor of aflatoxin biosynthesis, was studied. Mycelial samples obtained from A. parasiticus cultures exposed to an effective concentration of the leaf and seed extracts (50% v/v in culture media) produced approximately 90 and 75%, less aflatoxins respectively. Under these conditions semi-thin longitudinal and cross sections of the mycelia and vesicles showed attenuation of the cell wall at variable intervals causing deformation of the mycelium, vacuolation of the mycelial cytoplasm and vesicles. Herniation of the cytoplasmic contents which were protruding from the mycelium resulting in irregular mycelial shape. In addition, some mycelia showed a cleft between the cell wall and cytoplasm. Data obtained from microscopic observations may suggest that irreversible inhibition in aflatoxin biosynthesis by fungi due to neem extracts is partly due to mycelial cell wall damages.

In recent years, a lot of attention has been paid to quantum dot (QD) nanoparticles as fluorescent sensors for sensitive and accurate detection of cancer biomarkers. Here, using a homemade specific monoclonal antibody against CA125 and QD525- or FITC-labeled probes, expression of this marker in an ovarian cancer cell line and cancer tissues were traced and optical properties of fluorophores were compared qualitatively and quantitatively. Our results clearly showed that besides lower background and exceptionally higher photobleaching resistance, QD525 exhibited higher fluorescent intensity for both ovarian cancer cell and tissues at different exposure times (p<0.0001) and excitation filter sets (p<0.0001) exemplified by significantly higher staining index (p<0.016). More importantly, the FITC-labeled probe detected antigen-antibody complex at minimum concentration of 0.3 mg/mL of anti-CA125, while reactivity limit decreased to 0.078 mg/mL of anti-CA125 when QD525-labeled probe was applied showing four times higher reactivity level of QD525 probe compared to the same probe labeled with FITC. Based on our results, it seems that QDs are inimitable tags for sensitive detection and localization of ovarian cancer micrometastasis and molecular demarcation of cancer tissues in surgical practice, which subsequently figure out accurate therapeutic approaches.

Background: Oral Squamous Cell Carcinoma (OSCC) is among the ten most common cancers worldwide. Hypermethylation of CpG sites in the promoter region and subse-quent down-regulation of a tumor suppressor gene, TGM-3 has been proposed to be linked to different types of human cancers including OSCC. In this study, methylation sta-tus of CpG sites in the promoter region of TGM-3 has been evaluated in a cohort of pa-tients with OSCC compared to normal controls. Methods: Forty fresh tissue samples were obtained from newly diagnosed OSCC patients and normal individuals referred to dentistry clinic for tooth extraction. DNA was extract-ed, bisulfite conversion was performed and it was subjected to PCR using bisulfite-sequencing PCR (BSP) primers. Prepared samples were sequenced on a DNA analyzer with both forward and reverse primers of the region of interest. The peak height values of cytosine and thymine were calculated and methylation levels for each CpG site within the DNA sequence was quantified. Results: Quantitative DNA methylation analyses in CpG islands revealed that it was sig-nificantly higher in OSCC patients compared to controls. DNA methylation at CpG1/CpG3/CpG5 (p=0.004-0.01) and CpG1/CpG3 (p=0.001-0.019) sites was associated with tumor stage and grade, respectively. Male OSCC patients had higher methylation rate at CpG3 (p=0.032), while smoker patients showed higher methylation rate at CpG6 (p=0.045). Conclusion: These results manifested the contribution of DNA methylation of TGM-3 in OSCC and its potential association with clinico-pathologic parameters in OSCC.