Association of ET-1 gene polymorphisms with COPD phenotypes in a Caucasian population

Background and Aim. The phenotypic expression of COPD consists of pulmonary emphysema and chronic bronchitis. An imprecise phenotypic definition may result in inconsistencies among genetic studies regarding COPD pathogenesis. Endothelin-1 gene polymorphisms have been linked to increased susceptibility of COPD development. The present study examined the involvement of +138 insA/delA and G198T ET-1 polymorphisms with emphysematous and bronchitic COPD phenotypes. Methods. In order to narrow down the phenotypic choices to either COPD-associated pulmonary emphysema or chronic bronchitis, a DLCO<60% predicted threshold was chosen as an indicator of severe emphysema.116 COPD smokers and 74 non-related, non-COPD smokers were evaluated. Results. Statistical analysis showed that the 4A allele of the +138insA/delA SNP and the 4A:T haplotype were associated predominantly with a chronic bronchitis phenotype, whereas the TT genotype of the G198T SNP was found to be protective from emphysema development. Conclusions. The presence of both the 4A and T allele seems to modify the final expression of COPD towards a chronic bronchitis phenotype, since the G:3A haplotype was associated with a predominantly emphysematous phenotype in our study

Experimental study of gas flow through micro channels in the early transition regime

158 σ.Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Μικροσυστήματα και Νανοδιατάξεις”Σε αυτή την εργασία μελετήθηκε η ροή των αερίων ηλίου, αργού και αέρα σε διατάξεις μικροκαναλιών. Οι διατάξεις αυτές είναι κατασκευασμένες από PMMA και αποτελούνται από οκτώ κανάλια η κάθε μια που έχουν μήκος 5000 μm, πλάτος 285 μm και βάθος 20 μm και 30 μm. Η ροή των αερίων δημιουργήθηκε λόγω διαφοράς πίεσης μεταξύ δυο δεξαμενών και οι τιμές του αριθμού Knudsen κυμάνθηκαν από 0,2 έως 1,69 δηλαδή στην περιοχή ολίσθησης και στην αρχή της μεταβατικής περιοχής της ροής. Η παροχή μάζας μετρήθηκε μέσω των πιέσεων των δεξαμενών και συγκρίθηκε με θεωρητικά αποτελέσματα που προέκυψαν από τη λύση της γραμμικοποιημένης εξίσωσης BGK. Η απόκλιση μεταξύ θεωρητικών και πειραματικών αποτελεσμάτων αποδίδεται κυρίως σε διαρροές και ανακριβή μέτρηση των διαστάσεων των καναλιών και του όγκου των δεξαμενών.The flow of three gases, helium, argon and air through micro channels is examined experimentally in this study. The channels are made from PMMA and were 5000 μm long, with depths of 20 μm and 30 μm and width of 285. The cause of the flow was the pressure difference of the two tanks and Knudsen number varied from 0,2 to 1,69 (slip and early transition flow regimes). The mass flow rate was based on the pressure at the channels inlet and it was compared to computational results obtained by solving the linnearized BGK equation. Differences between theory and experiment are primarily attributed to mass leak and uncertainties with regard to channel dimensions and tank volume.Γεώργιος Α. Καπαριανό

Clinical application of the SurePath liquid-based Pap test in cytological screening of bronchial brushing for the diagnosis of lung cancer

The SurePath liquid-based Pap test (LPT) is successfully and widely used to assess sputum cytology. This study aimed to compare the cytological findings and diagnostic sensitivity of LPT with those of the conventional Pap smear (CPS) method for diagnosing lung cancer. Bronchial brushing specimens from 204 patients diagnosed with lung cancer were studied. LPT slides showed decreased areas of cell monolayers, a clearer background and distinct, stereoscopic cytological features. The LPT had a significantly higher diagnostic sensitivity for lung cancer (71.6%) than the CPS method (57.8%, p < 0.05), particularly for small cell lung carcinoma and >2 cm lesions (p < 0.05). Combination of the LPT with the CPS method showed obviously higher diagnostic sensitivity for the detection of adenocarcinoma (63.6%), central lesions (85.0%) and >2 cm lesions (81.4%) compared with the CPS method alone (p < 0.05, p < 0.01). Thus, LPT is a useful and easily performed technique that can be widely applied, and is suitable for the early diagnosis of lung cancer

Polymorphisms in nitric oxide synthase and endothelin genes among children with obstructive sleep apnea

BACKGROUND: Obstructive sleep apnea (OSA) is associated with adverse and interdependent cognitive and cardiovascular consequences. Increasing evidence suggests that nitric oxide synthase (NOS) and endothelin family (EDN) genes underlie mechanistic aspects of OSA-associated morbidities. We aimed to identify single nucleotide polymorphisms (SNPs) in the NOS family (3 isoforms), and EDN family (3 isoforms) to identify potential associations of these SNPs in children with OSA. METHODS: A pediatric community cohort (ages 5–10 years) enriched for snoring underwent overnight polysomnographic (NPSG) and a fasting morning blood draw. The diagnostic criteria for OSA were an obstructive apnea-hypopnea Index (AHI) >2/h total sleep time (TST), snoring during the night, and a nadir oxyhemoglobin saturation <92%. Control children were defined as non-snoring children with AHI <2/h TST (NOSA). Endothelial function was assessed using a modified post-occlusive hyperemic test. The time to peak reperfusion (Tmax) was considered as the indicator for normal endothelial function (NEF; Tmax<45 sec), or ED (Tmax≥45 sec). Genomic DNA from peripheral blood was extracted and allelic frequencies were assessed for, NOS1 (209 SNPs), NOS2 (122 SNPs), NOS3 (50 SNPs), EDN1 (43 SNPs), EDN2 (48 SNPs), EDN3 (14 SNPs), endothelin receptor A, EDNRA, (27 SNPs), and endothelin receptor B, EDNRB (23 SNPs) using a custom SNPs array. The relative frequencies of NOS-1,-2, and −3, and EDN-1,-2,-3,-EDNRA, and-EDNRB genotypes were evaluated in 608 subjects [128 with OSA, and 480 without OSA (NOSA)]. Furthermore, subjects with OSA were divided into 2 subgroups: OSA with normal endothelial function (OSA-NEF), and OSA with endothelial dysfunction (OSA-ED). Linkage disequilibrium was analyzed using Haploview version 4.2 software. RESULTS: For NOSA vs. OSA groups, 15 differentially distributed SNPs for NOS1 gene, and 1 SNP for NOS3 emerged, while 4 SNPs for EDN1 and 1 SNP for both EDN2 and EDN3 were identified. However, in the smaller sub-group for whom endothelial function was available, none of the significant SNPs was retained due to lack of statistical power. CONCLUSIONS: Differences in the distribution of polymorphisms among NOS and EDN gene families suggest that these SNPs could play a contributory role in the pathophysiology and risk of OSA-induced cardiovascular morbidity. Thus, analysis of genotype-phenotype interactions in children with OSA may assist in the formulation of categorical risk estimates