CYP and GST polymorphisms and survival in advanced non-small cell lung cancer patients

Several polymorphisms in cytochrome P-450s (CYP)s and Glutathione S-transferases (GST)s have been reported to be associated with survival rates of patients with non-small cell lung cancer (NSCLC) but the studies in this regard are scarce and the results are contradictory. In this study, CYP1A1 (Ile462Val), CYP1B1(Asn453Ser), GST M1, GSTP1 exon 5 (Ile105Val) and exon 6(Ala114Val) and GSTT1 polymorphisms were determined in 138 patients with advanced NSCLC to evaluate their role in survival. Of the studied CYP and GST polymorphisms only GSTP1 exon 6 variant significantly altered (improved) the survival compared to wild type (p=0.036) with median survival of 22.2 months and 16.1 months, respectively. Multivariate analysis also revealed a significant reduction of adjusted hazard ratio of death associated only with the GSTP1 exon 6 variant genotype of 0.45 (95% confidence interval (95% CI), 0.23-0.89, p=0.022). These results show that the GSTP1 exon 6 variant genotype is associated with improved survival in the patients with advanced NSCLC.

KEYWORDS

Cytochrome P-450, glutathione S-transferase, non small cell lung cancer, polymorphism, survival.

Diffuse panbronchiolitis observed in a white man in Turkey

Diffuse panbronchiolitis (DPB) is a distinct clinicopathological entity which is characterized by chronic recurrent sinopulmonary infection and inflammation. It is prevalent in the Far East, but extremely rare in western countries. In this report, we described the first Turkish case of DPB and also evaluated demographic and diagnostic characteristics of 18 patients with DPB, previously reported from non-Asian countries. We believe that DPB patients described from these countries may also increase if this disease is taken into consideration in differential diagnosis of sinopulmonary diseases. Another consideration is that, since the treatment and prognosis of DPB are different from other obstructive pulmonary diseases, it should not be mistaken for others.

Abnormal middle ear pressures during experimental influenza A virus infection--role of Eustachian tube function

INTRODUCTION

Experimental infection of adults with influenza A virus, rhinovirus or RSV causes abnormal ME pressure in some, but not all subjects. The hypothesis tested in this study is that the response variability is caused by constitutional differences in the functioning of the Eustachian tube.

METHODS

18 adult subjects were experimentally infected with influenza A virus. On five occasions before virus exposure, middle ear pressure (by tympanometry) and Eustachian tube function (by sonotubometry) were recorded bilaterally. Tests were repeated on days 1 through 8 and 10 after infection. Individual ears were classified with respect to the number of pre-exposure, positive sonotubometric testings and the middle ear pressure response to infection was compared between ears with Eustachian tube openings at all pre-infection test sessions (GR-A) and those with at least one negative test (GR-B).

RESULTS

Pre-exposure, 19, six, four, four, one and two ears had tubal openings on five, four, three, two, one and zero sessions, respectively. For that period, GR-A had significantly lesser average intra-ear and intra-group middle ear pressure variances compared to GR-B, but there were no between-group differences in the average middle ear pressure or in the number of observations of abnormal middle ear pressure. After virus exposure, middle ear pressure variances and the number of abnormal observations increased and the average pressure decreased in both groups, but the effects were more pronounced for GR-B ears.

CONCLUSIONS

These results support the hypothesis that pre-existing good Eustachian tube function reduces the otological complications of viral upper respiratory tract infection.

Treatment of chronic suppurative otitis media with topical tobramycin and dexamethasone

OBJECTIVES

To investigate the safety and efficacy of a topical combination of tobramycin and dexamethasone in a primate model of chronic suppurative otitis media (CSOM) and to explore the contribution of the added topical steroid for the treatment of CSOM.

DESIGN

Blinded, randomized, placebo-controlled trial.

SUBJECTS

Sixty juvenile cynomolgus monkeys randomized into the following 6 treatment groups of 10 monkeys each: 0.3% tobramycin (group 1), combined 0.3% tobramycin-0.1% dexamethasone (group 2), combined 1.0% tobramycin-0.33% dexamethasone (group 3), 0.1% dexamethasone (group 4), vehicle (group 5), and phosphate-buffered saline solution (group 6).

INTERVENTIONS

Chronic suppurative otitis media was established by inoculating the right ear with Pseudomonas aeruginosa. After 4 weeks of drainage, animals were treated according to the group assignment with 3 drops twice daily for 7 weeks. Hearing thresholds were monitored with repeated auditory brainstem response testing (ABR), and clinical response was monitored with repeated otoscopic examinations and cultures throughout the study. Cytocochleograms were evaluated for quantification of outer hair cell loss.

RESULTS

Rapid resolution of otorrhea and eradication of P aeruginosa occurred in all groups receiving tobramycin. The inclusion of dexamethasone accelerated the resolution of otorrhea and negative yields of cultures compared with tobramycin alone. Otorrhea and positive culture findings persisted in the groups not treated with topical antibiotic. Results of ABRs at 4 and 8 weeks and cytocochleograms for outer cell hair loss were not affected by drug administration. Perilymph samples collected at the end of the study showed no detectable tobramycin.

CONCLUSIONS

Combined tobramycin-dexamethasone ear drops were safe and effective in the monkey CSOM model. Dexamethasone enhanced the efficacy of tobramycin.