Supports of ceramic mixture for acelerated growth of Mycobacterium smegmatis

Mycobacterium smegmatis (Ms), with its short generation time and low biosafety requirements, serves as an appropriate model to study Mycobacteria in general and is useful for assays of anti-tuberculosis agents. Recently, ceramic materials have been used in biomedical applications as a substrate. The aim of this work was to evaluate the ability of growth by Ms over supports prepared with a ceramic mixture. The supports were synthetized from hydroxyapatite (HA) and In2TiO5. SEM, EDS and XRD were used for analyze its final chemical composition. The increase of the oxygen concentration it is attributed to photocatalytic effect promoted by the sunlight exposure of supports immersed on MDB 7H9. The ceramic mixture, was responsible of the oxygen increase and, consequently, of the increase of eight times on the minimal inhibitory concentration in rezasurine assays on microplate. The use of the ceramic support showed the Ms growth 24 h before respect to the control without support.  

Antiproliferative and apoptotic activities of extracts of Asclepias subulata

CONTEXT

Asclepias subulata Decne. (Apocynaceae) is a shrub used in the Mexican traditional medicine for the treatment of cancer.

OBJECTIVE

The objective of this study was to evaluate the antiproliferative activity of methanol extract of aerial parts of A. subulata and its fractions against different cancer cell lines. Additionally, we analyzed the mechanism of action of the active fractions.

MATERIALS AND METHODS

Methanol extract fractions were prepared by serial extraction with n-hexane, ethyl acetate, and ethanol. The antiproliferative activity of methanol extract and its fractions was evaluated, against several murine (M12.C3.F6, RAW 264.7, and L929) and human (HeLa, A549, PC-3, LS 180, and ARPE-19) cell lines by the MTT assay, using concentrations of 0.4-400 µg/mL for 48 h. Ethanol and residual fractions were separated using silica gel column. Apoptosis induction of cancer cells was evaluated by Annexin and JC-1 staining using flow cytometry.

RESULTS

Methanol extract and its fractions showed antiproliferative activity against all human cancer cell lines tested. Methanol extract had the highest antiproliferative activity on A549 and HeLa cells (IC50 values < 0.4 and 8.7 µg/mL, respectively). Ethanol and residual fractions exerted significant antiproliferative effect on A549 (IC50 < 0.4 µg/mL) and PC3 cells (IC50 1.4 and 5.1 µg/mL). Apoptotic assays showed that CEF7, CEF9, CRF6, and CRF5 fractions induced mitochondrial depolarization in A549 cells, 70, 73, 77, and 80%, respectively. Those fractions triggered the apoptosis mitochondrial pathway.

CONCLUSION

Our data show that A. subulata extracts have potent antiproliferative properties on human cancer cell lines. This plant should be considered an important source of potent anticancer compounds.

Is age a risk factor for esophagectomy?

In recent years, the number of elderly patients with esophageal cancer as well as the number submitted for esophageal resection has been increasing. With respect to nutritional and pulmonary evaluations, surgical staging, and mortality, 37 patients over the age of 65 who underwent esophagectomy and simultaneous reconstruction were analyzed. This group was compared statistically with a group of 162 patients younger than 65 to determine whether age was a factor influencing treatment and outcome. There was no statistical difference between the groups relating to the described variables. Age should not be a limiting factor when it comes to offering an aggressive surgical approach for the esophageal cancer patient aged 65 or more. This approach can be performed as safely in older patients as it is in younger patients, with similar incidence of mortality.