A study on the effect of petrographic composition on the grindability of coal at selected mineral matter levels

Keeping the mineral matter content at selected levels, the effect of petrographic composition on the grindability has been studied in the case of four East Bokaro coals of similar rank. It is observed that in each 5%, 10% and 20% MM levels, Hardgrove Grindability index falls rapidly at first with increasing petrographic index and then rises but at a different rate

Environmental education and sustainable development

Meeting: International Conference on Environmental Education, 3d, 3-7 Oct. 1989, Goa, I

Synthesis and SAR evaluation of novel thioridazine derivatives active against drug-resistant tuberculosis

The neuroleptic drug thioridazine has been recently repositioned as possible anti-tubercular drug. Thioridazine showed anti-tubercular activity against drug resistant mycobacteria but it is endowed with adverse side effects. A small library of thioridazine derivatives has been designed through the replacement of the piperidine and phenothiazine moieties, with the aim to improve the anti-tubercular activity and to reduce the cytotoxic effects. Among the resulting compounds, the indole derivative 12e showed an antimycobacterial activity significantly better than thioridazine and a cytotoxicity 15-fold lower

Promoter methylation and silencing of the retinoic acid receptor-beta gene in lung carcinomas

BACKGROUND: Retinoic acid plays an important role in lung development and differentiation, acting primarily via nuclear receptors encoded by the retinoic acid receptor-beta (RARbeta) gene. Because receptor isoforms RARbeta2 and RARbeta4 are repressed in human lung cancers, we investigated whether methylation of their promoter, P2, might lead to silencing of the RARbeta gene in human lung tumors and cell lines. METHODS: Methylation of the P2 promoter from small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) cell lines and tumor samples was analyzed by the methylation-specific polymerase chain reaction (PCR). Expression of RARbeta2 and RARbeta4 was analyzed by reverse transcription-PCR. Loss of heterozygosity (LOH) was analyzed by PCR amplification followed by electrophoretic separation of PCR products. Statistical differences were analyzed by Fisher's exact test with continuity correction. RESULTS: The P2 promoter was methylated in 72% (63 of 87) of SCLC and in 41% (52 of 127) of NSCLC tumors and cell lines, and the difference was statistically significant (two-sided P:<.001). By contrast, in 57 of 58 control samples, we observed only the unmethylated form of the gene. Four tumor cell lines with unmethylated promoter regions expressed both RARbeta2 and RARbeta4. Four tumor lines with methylated promoter regions lacked expression of these isoforms, but demethylation by exposure to 5-aza-2'-deoxycytidine restored their expression. LOH at chromosome 3p24 was observed in 100% (13 of 13) of SCLC lines and 67% (12 of 18) of NSCLC cell lines, and the difference was statistically significant (two-sided P: =.028). CONCLUSIONS: Methylation of the RARbeta P2 promoter is one mechanism that silences RARbeta2 and RARbeta4 expression in many lung cancers, particularly SCLC. Chemical demethylation is a potential approach to lung cancer therap