Analysis of CT features and quantitative texture analysis in patients with lung adenocarcinoma: a correlation with EGFR mutations and survival rates.

AIM: To investigate the correlation between conventional computed tomography (CT) features, quantitative texture analysis (QTA), epidermal growth factor receptor (EGFR) mutations, and survival rates in patients with lung adenocarcinoma. MATERIALS AND METHODS: Sixty-eight patients were evaluated for conventional CT features and QTA in this retrospective study. A multiple logistic regression analysis and receiver operating characteristics (ROC) curve analysis versus death and EGFR status was performed for CT features and QTA in order to assess correlation between CT features, QTA, EGFR mutations, and survival rates. A p-value <0.05 was regarded to indicate a statistically significant association. RESULTS: An EGFR mutation was identified in 26/68 tumours (38.2%). A negative association was found between EGFR mutation and emphysema (p < 0.0001) whereas a positive correlation was found with necrosis (p=0.017), air bronchogram (p=0.0304), and locoregional infiltration (p=0.0018). Mean, standard deviation, and skewness were found to have significant correlation with EGFR mutation (p=0.0001; p=0.0001; p=0.0459; Fig 3). The only parameter correlated with the event death was entropy (r=0.2708; p=0.0329). CONCLUSION: Both qualitative and quantitative analysis disclosed potential associations between CT features and QTA parameters, EGFR mutations and prognosis; these correlations need to be confirmed in larger studies to be used as imaging biomarkers in the management of patients affected by lung adenocarcinoma.

Radiation-induced health effects on atmospheric flight crew members: clues for a radiation-related risk analysis.

There are few human data on low-dose-rate-radiation exposure and the consequent acute and late effects. This fact makes it difficult to assess health risks due to radiation in the space environment, especially for long-term missions. Epidemiological data on civilian flight personnel cohorts can provide information on effects due to the low-dose and low-dose rate mixed high- and low-LET radiation environment in the earth's atmosphere. The physical characteristics of the radiation environment of the atmosphere make the results of the studies of commercial flight personnel relevant to the studies of activities in space. The cooperative international effort now in progress to investigate dose reconstructions will contribute to our understanding of radiation risks for space exploration.

Health risks from radiation exposure for civilian aviation flight personnel: a study of Italian airline crew members.

A study of the effects of exposures of civilian aviation flight personnel to atmospheric ionizing radiation (including high-energy neutrons) is being performed. The results of previous studies and of the criteria required for a more satisfactory outcome in future studies are presented, along with a description of the protocol for the Italian national study. A description of the cohort is given in terms of its size, composition and member eligibility. The various ways of determining the exposure and the health status of past and current aircrew members are discussed, and follow-up procedures are described. An overview of the data management and processing philosophy adopted in the Italian study is given with regard to flight routes, radiation dose evaluation along the flight paths, and construction of exposure matrices. Other studies of potential interest are also discussed. The study is still in progress, so the results are preliminary.

Radiation-induced biological effects on crew members: a combined analysis on atmospheric flight personnel.

Human data on low dose rate radiation exposure and its effects are not readily available. A huge amount of such data may be obtained through flight personnel cohorts, in the form of epidemiological studies on delayed health effects induced by the cosmic-ray generated atmospheric ionizing radiation, to which flight personnel are exposed all throughout their work activity. All the available results from different studies on flight personnel exposure have been combined in various ways to evaluate the association between atmospheric ionizing radiation environment and health risks and to assess directions for future investigations.

Radiation exposure of civilian airline crew members and associated biological effects due to the atmospheric ionizing radiation environment.

A study, currently in progress, on the radiation exposure and the associated biomedical effects due to the atmospheric ionizing radiation environment for the Italian civilian aviation flight personnel is sketched. After a presentation of the considered data sources, a description of the cohort is given, in terms of criteria for eligibility, and cohort construction, size and composition. Then the protocol for the Italian study is presented: the various ways of investigating the exposure and the health status of past and currently employed aircrew members and follow-up procedures are shown. An overview is given of the data management and processing philosophy with regards to flight routes, radiation dose evaluation along the flight path and exposure matrix building, as adopted in the Italian study. Potential side studies of interest are also shown.

Binding and internalization of VIP in rat intestinal epithelial cells.

We have prepared villous cells from the jejunum of the rat small intestine and studied the effects of divalent cations and bacitracin on the binding and internalization of VIP. Villous epithelial cells (4 x 10(6) cells/ml) were suspended in a Hepes-NaCl buffer with 1.0% BSA, (pH 7.4) and the cells were incubated for varying periods of time with 125I-VIP at 24 degrees C. Specific binding of radiolabeled VIP was maximal within 10 min (10%) and slowly declined to 9.0 percent after 30 min. In the presence of 1.0 mg/ml bacitracin, however, maximal specific binding of VIP was only 2.7 percent (P less than or equal to 0.001). The addition of CA2+ or Mg2+ to the buffer significantly decreased binding of VIP in a concentration dependent manner. At 8.0, 4.0, 2.0 and 1.0 mM Ca2+, binding of 125I-VIP decreased by 70, 60, 40 and 25 percent, whereas in the presence of the same concentrations of Mg2+ binding was decreased to 50, 38, 25 and 10 percent (P less than or equal to 0.01). To determine if epithelial cells internalize VIP, we bound 125I-VIP to villous cells and then differentiated surface-bound and internalized radioactivity by treating with trypsin (150 micrograms/ml). Surface bound radioligand was the same at both 24 and 4 degrees C (5.3%), while internalized 125I-VIP was 4.0% at 24 degrees C compared to only 1.0% at 4 degrees C (P less than or equal to 0.001). At 24 and 4 degrees C, both Ca2+ (4.0 mM) and Mg2+ (8.0 mM) decreased surface bound radioligand by 60 percent (P less than or equal to 0.01) and lowered internalized radioactivity. These data demonstrate that (1) bacitracin decreases the binding of VIP to small intestinal epithelial cells, (2) both Ca2+ and Mg2+ affect the binding of VIP to its surface receptor and (3) VIP is internalized into epithelial cells.