IL18 and IL18R1 polymorphisms, lung CT and fibrosis: A longitudinal study in coal miners

It has been suggested that interleukin (IL)-18 plays a role in the development of inflammatory and fibrosing lung diseases. Associations of polymorphisms in the genes coding for IL-18 (IL18 /G-656T, C-607A, G-137C, T113G, C127T) and its receptor (IL18R1 /C-69T) with coal workers' pneumoconiosis (CWP) were studied in 200 miners who were examined in 1990, 1994 and 1999. Coal-dust exposure was assessed according to job history and ambient measures. The main health outcome was lung computed tomography (CT) score in 1990. Internal coherence was assessed by studying CT score in 1994, 4-yr change in CT score and CWP incidence and prevalence. CT score in 1990 was a good predictor of radiographic grade in 1999 and, therefore, an appropriate subclinical quantitative trait. The IL18 -137C allele was associated with lower CT score in 1990 and 1994 (1.24 versus 1.69 and 1.57 versus 2.46, respectively), slower progression of CT score between 1990 and 1994 and lower pneumoconiosis prevalence in 1999 relative to the G allele (0.33 versus 0.77 and 8.2 versus 19.6%, respectively). Smoking- or dust-adjustment, and stratification on IL18R1 genotype and adjustment for haplotype effects did not change the conclusions. In conclusion, the results of the present study suggest a role for IL18 in reducing the development of this fibrosing lung disease.

[Evaluation of water-soluble vitamins in the vitamin preparation Spofavit dragée using reversed-phase HPLC]

A reversed-phase HPLC gradient method with good separation efficiency was developed and validated for the evaluation of water-soluble vitamins in the pharmaceutical preparation Spofavit dragee. Analyses were performed on a C8 column (LiChrospher RP-select B), the mobile phase was a mixture of phosphate buffer with sodium hexanesulphonate and acetonitrile. Detection was at 280 and 210 nm. The method is capable within 7 minutes to evaluate 6 water-soluble vitamins (ascorbic acid, nicotinamide, panthotenate.Ca, pyridoxine.HCl, thiamine.HCl, and riboflavin). All validated parameters of this method are discussed; the developed method appeared robust and suitable for evaluation of water-soluble vitamins in vitamin preparations.

Reversed-phase HPLC methods for purity test and assay of pioglitazone hydrochloride in tablets

A reversed-phase gradient HPLC method was developed for the evaluation of pioglitazone hydrochloride (PG-HCl) in tablets. Limit of detection for PG-HCl was found to be 42 ng/ml. Analyses were performed on a C18 column (Symmetry C18, 5 microm, 250 x 4.6 mm), mobile phase was a mixture of ammonium formate buffer adjusted with formic acid to pH 4.1 and acetonitrile. Shortened purity method was used as the assay method. Methods were validated.

HPLC method with UV detection for evaluation of digoxin tablet dissolution in acidic medium after solid-phase extraction

A simple and reliable method for the evaluation of dissolution of digoxin tablets in 0.01 M hydrochloric acid was developed. Digoxin and its degradation products after solid-phase extraction using C18 Sep-Pak cartridges were evaluated. Analyses were performed on C18 column (LiChrospher RP-18e, 5 microm, 125 x 4.0 mm), as mobile phase water and acetonitrile (72:28, v/v) were used. Detection wavelength was 218 nm. Identity of digoxin degradation products was confirmed by HPLC-MS.

Effect of TNF and LTA polymorphisms on biological markers of response to oxidative stimuli in coal miners: a model of gene-environment interaction. Tumour necrosis factor and lymphotoxin alpha

INTRODUCTION

Interaction between genetic background and oxidative environmental stimuli in the pathogenesis of human lung disease has been largely unexplored.

METHODS

A prospective epidemiological study was undertaken in 253 coal miners. Intermediate quantitative phenotypes of response to oxidant exposure, including erythrocyte glutathione peroxidase (GSH-Px) and catalase activities, were studied. Oxidant exposures studied were smoking habits and cumulative dust exposure assessed by job history and ambient measures. Disease phenotypes included subclinical computed tomography score at the first survey and x ray profusion grades twice, five years apart, to assess established coal workers' pneumoconiosis (CWP). Miners were genotyped for common functional polymorphisms in the gene for tumour necrosis factor alpha (TNF) and lymphotoxin alpha (LTA), two proinflammatory cytokines that have been implicated in the pathogenesis of chronic lung diseases.

RESULTS

Regarding gene-environment interaction on intermediate phenotypes, results showed interaction of a promoter polymorphism at the -308 position in TNF with occupational exposure on erythrocyte GSH-Px activity with a significant association in those with high exposure (p=0.003), whereas no association was observed among those with low exposure (interaction p=0.06). Regarding gene intermediate phenotype interaction on clinical outcome, results showed an association of CWP prevalence with an NcoI polymorphism in LTA in those with low catalase activity (p=0.05), whereas no association was observed in those with high activity (interaction p=0.03). No other significant association was observed.

CONCLUSION

The results suggest that interactions of genetic background with environmental exposure and intermediate response phenotypes are important components in the pathogenesis of CWP.

Glioblastoma-related gene mutations and over-expression of functional epidermal growth factor receptors in SKMG-3 glioma cells

Amplification of the epidermal growth factor receptor (EGFR) gene is found in about 40% of glioblastomas (GBMs) but is rarely detected in GBM cell lines. We confirmed that the exceptional SKMG-3 GBM cell line retained amplified EGFR genes in vitro, and found that these sequences were concentrated on extra-chromosomal DNA particles similar to double-minute chromosomes. The cells contained two other gene mutations that are associated with high-grade astrocytic tumors: extra-chromosomal amplification of the cyclin-dependent kinase-4 (CDK4) gene and a homozygous mutation within the PTEN tumor suppressor gene. Immunoblots revealed very high levels of EGFR, moderately increased expression of CDK4, and no detectable PTEN protein. The overexpressed SKMG-3 EGFRs responded to exogenous ligand and resembled normal rather than mutant receptors. A heterozygous mutation of the p53 gene (p53R282W) correlated with failure of radiation to induce the expression of cyclin-dependent kinase inhibitor p21waf1 or an early G1 cell cycle arrest. Although each of these gene mutations occurs in GBMs, SKMG-3 cells had an unusual genotype in that a p53 gene mutation co-existed with amplified EGFR genes. Nonetheless, the SKMG-3 cell line can be exploited as a model to study how oncogenic EGFR signals in GBM cells interact with over-expressed CDK4 and loss of PTEN to confer the malignant phenotype.

Concordant methylation of the ER and N33 genes in glioblastoma multiforme

Methylation of promoter-associated CpG islands appears to be a potential way by which tumor suppressor genes are inactivated in cancer. Using Southern blot analysis, we have studied the methylation of several genes in glioblastoma multiforme (GBM), trying to determine their contribution to tumorigenesis. Genes studied included the estrogen receptor (ER), N33, the candidate tumor-suppressors P15, P16 and HIC1 and a control gene, c-abl. Hypermethylation of N33, ER, HIC1, P16, P15 and c-abl were found in 61%, 59%, 60%, 5%, 2% and 0% of GBM respectively. HIC1 methylation was detected in normal brain as well, but appeared to be more extensive in tumors. ER and N33 methylation were significantly more frequent in tumors from individuals over the age of 40 (70% and 88% vs 36% and 14%). In addition, there was a strong association between ER and N33 methylation, which were concordant in 81% of the cases (P<0.01). ER and N33 methylation in GBM may therefore appear as a result of shared etiologic factors, which may relate in part to aging cell populations in the brain.

Linkage analysis of susceptibility to ozone-induced lung inflammation in inbred mice

Exposures to the common air pollutant ozone (O3) cause decrements in pulmonary function and induce airway inflammation that is characterized by infiltration of polymorphonuclear neutrophils (PMNs; refs 1-4). Because of the impact that O3 may have on public health, it is critical to identify susceptibility factors. Highly reproducible, significant inter-individual variations in human pulmonary function responses to O3 support the hypothesis that genetic background is an important determinant. Initial analysis of PMN responses to O3 exposure in segregant populations derived from inflammation-prone (susceptible) C57BL/6J (B6) and inflammation-resistant C3H/HeJ (C3) inbred mice indicated that susceptibility was controlled by a locus we termed Inf2 (ref. 7). Subsequent analyses with recombinant inbred strains suggested that a more complex interaction of genes is involved. In this report, we identify a quantitative trait locus (QTL) for O3 susceptibility on chromosome 17. Candidate genes for the locus include Tnf, the gene encoding the pro-inflammatory cytokine tumour necrosis factor-alpha (Tnf). Antibody neutralization of the protein product of this putative candidate gene significantly protected against O3 injury in susceptible mice. These results strongly support linkage of O3 susceptibility to a QTL on chromosome 17 and Tnf as a candidate gene.