Biologie moléculaire : accès libre

Introduction: Buruli ulcer (BU) is a serious skin disease caused by Mycobacterium ulcerans. According to WHO, 70% of BU cases should be confirmed by the PCR-IS2404 gene amplification. The objective of this study is to validate a real-time PCR for the detection of M. ulcerans in clinical and environmental samples.
Methodology: A total of 70 clinical samples, 10 M. ulcerans strains and 15 environmental samples were tested by Ziehl-Neelsen staining technique, conventional PCR, real time qPCR and culture. The proportion of positive cases of M. ulcerans detection between the different tests was compared by the Chi-square test. The difference was
statistically significant for a P-value ≤ 0.05.
Results: Out of 33/80 samples were cultured positive (41.25%) to M. ulcerans, 41/80 ZN staining were positive (51.25%) to AFB at the microscopy, 55/80 (68.75%) and 64/80 samples (80%) were positive to the IS2404 insertion sequence from conventional PCR and qPCR respectively. Both PCR techniques showed positivity rates significantly
higher than microscopy and culture (P=0.002). However, no significant difference of positive rate was observed between the two types of PCR (P=0.38). In contrast, the detection limit for the real time qPCR was lower (0.01copies/ μL) compared to conventional PCR. Only qPCR was able to detect IS2404 in 2/15 environmental samples (13.3%).
Conclusion: This study showed the high sensitivity of the real time PCR for the detection of Mycobacterium ulcerans in clinical and environmental samples.

Multipotent adult stem cells have been promoted and utilized in the treatment of autoimmune diseases. Autoimmune diseases (AD) are nquestionably debilitating, not only by diminishing quality of life, but also these disorders significantly reduce life span. To date, prevalent drug treatments acting to curb AD seem to be ineffective, thus there is a critical need to find alternative treatments. Stem cells derived from the umbilical cord blood and tissue, bone marrow, adipose, amniotic fluid, placental, and dental pulp have been recently used for treating some of these diseases. Here we highlight the current use of umbilical cord mesenchymal stem cells (UCMSC) on Rheumatoid Arthritis, Lupus, Inflammatory Bowel Disease, Multiple Sclerosis, Type I Diabetes, and Psoriasis.

The abnormal expression of miR-193a-3p was associated mostly with the development and progress of the tumors. In the present study, the expression levels of miR-193b-3p and its associated mRNAs were measured by reverse transcription-quantitative polymerase chain reaction, and the methylation levels of its promoter were detected via the methylation-specific PCR in serum and tissues of patients with esophageal squamous cell carcinoma (ESCC). The results demonstrated that the expression level of miR-193b-3p were significantly decreased in preoperative serum and cancer tissues in patients with ESCC (p<0.01). The expression level of miR-193b-3p significantly was upregulated in serum after surgical removal of the cancerous tissue in ESCC patients (p<0.01). The target gene CCND1 of miR193a-3p showed the high expression in the tumor tissues, and its up- and down-stream gene Rb and p16 showed the low expression; and the target gene IGF1R and its up- and down-stream gene IGF1 and PI3K showed the high expression. The methylation level of miR-193a-3p in the promoter region was higher significantly in the tumor tissues than that in the adjacent non-cancerous tissues (p<0.01). This showed that the high methylation of genetic promoter region of miR-193b-3p might inhibit the expression of miR-193b-3p and further the regulation of CCND1 and IGF1R, as well as the relevant signaling pathways, facilitating the development and progress of ESCC.