[Diagnostic value of HBP, PCT combined with APACHE Ⅱ score respectively in ventilator-associated pneumonia]

Objective: To evaluate the diagnostic value of the heparin-binding protein (HBP), procalcitonin (PCT) and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score in ventilator-associated pneμmonia (VAP). Methods: A total of 160 patients who required tracheotomy or intubation and assisted breathing with invasive mechanical ventilator from the First Affiliated Hospital of Zhengzhou University from January 2015 to January 2017 was included in this prospective study,and divided into VAP group and no-VAP group based on if VAP happened or not; the VAP group was further divided into deterioration group and improvement group based on the curative effect after anti-infective treatment for 1 week. A total of 40 community acquired pneumonia (CAP) patients and 30 healthy volunteers were also included as control groups. The levels of HBP and PCT in blood of the subjects were tested with enzyme-linked immuno sorbent assay (ELISA) and chemiluminescence immunoassay (ECLIA) respectively, APACHE Ⅱ score was utilized to assess the severity of illness. The difference of HBP, PCT levels and APACHE Ⅱ score among the groups were analyzed. Receiver operating characteristic(ROC) curve was utilized to analyze the diagnostic value of HBP, PCT, APACHE Ⅱ score in VAP. Results: A total of 230 subjects participated in this study, including 68 VAP patients, 92 non-VAP patients, 40 CAP patients and 30 healthy volunteers. Before administration of mechanical ventilation, there were no statistically significant differences in HBP, PCT and APACHE Ⅱ score between VAP group and non-VAP group (all P>0.05). The levels of HBP,PCT and APACHE Ⅱ score were (41.4±21.3) μg/L,(0.355±0.254) μg/L,(13.4±2.5) respectively when the VAP was diagnosed,which were higher than those within the first 12 h of mechanical ventilation (7.3±2.7) μg/L, (0.080±0.038) μg/L, (8.4±2.0), all P<0.001). The HBP, PCT and APACHE Ⅱ score had no significant difference between within the first 12 h of mechanical ventilation and after mechanical ventilation in non-VAP group (all P>0.05). The levels of HBP was positively correlated with PCT and APACHE Ⅱ score (r=0.82, 0.68, all P<0.001). In deterioration group,the HBP,PCT and APACHE Ⅱ score after 1 week of anti-infective treatment were higher than those when the VAP was diagnosed (all P<0.001). No matter it is when the VAP was diagnosed or after anti-infective treatment for 1 week,the levels of HBP, PCT and APACHE Ⅱ score in deterioration group were higher than those in the improvement group (all P<0.001). The area under curve (AUC) of HBP+APACHE Ⅱ score, PCT+APACHE Ⅱ score for VAP diagnosis was 0.98, 0.95 respectively. The sensitivity of HBP+APACHE Ⅱ score in the diagnosis of VAP was lower than PCT+APACHE Ⅱ score (94.1% vs 95.6%),and the specificity was higher (92.4% vs 82.6%). Conclusion: The diagnostic value of HBP+APACHE Ⅱ score for early VAP is superior to PCT+APACHE Ⅱ score.

[Clinical significance of low-dose CT performed for three consecutive years in diagnosis of lung nodules in coal mine workers with 20 working years]

Objective: To investigate the clinical significance of low-dose CT (LDCT) in coal mine workers with relatively long working years. Methods: A total of 907 coal mine workers with ≥20 working years were enrolled, among whom there were 863 male and 44 female workers with a mean age of 49.5 years. Digital radiography (DR) was performed for these workers in 2013, and LDCT was performed for three consecutive years from 2014 to 2016. Results: A total of 32 workers were found to have lung nodules by DR in 2013, while in 2014, 269 workers were found to have non-calcified lung nodules by LDCT, and there was a significant difference in the number of workers with lung nodules (χ(2)=233.73, P<0.005) . There was also a significant difference in the detection rate of nodules between the workers with different working years of dust exposure (χ(2)=6.648, P=0.00) . The male workers had a significantly higher detection rate of nodules than the female workers (χ(2)=5.690, P=0.017) . There was no significant difference in the number of nodules between workers with different types of work (χ(2)=16.985, P=0.05) . There were 443 lung nodules in total, among which 71.56% were solid nodules and 55.75% had a size of ≤4mm; malignant nodules were confirmed by surgery in 6 (0.66%) of the 907 workers after baseline LDCT. LDCT reexamination in 2015 and 2016 found new nodules in 8 workers and enlarged nodules in 3 workers, and there was no significant change in the number of nodules with a size of ≤4 mm. Conclusions: It is necessary to perform high-risk population screening for coal mine workers by LDCT. The follow-up strategies for nodules with a size of ≤4mm are the same as those for negative results; annual reexamination is recommended for nodules with a size of >4-8 mm, and clinical treatment should be considered for nodules with a size of >8 mm.

Cytogenetic effects induced by accelerated carbon ions with shielding

Our work aims to understand the effects of shielding on the induction of biological damage by heavy charged particles and to compare the shielding effects of different materials at the same LET from two aspects: the biological effectiveness including or not including secondary particles emitted at large angles and the biological effectiveness at different angles with respect to the beam direction. We designed and conducted biological experiments to determine the biological effectiveness of 200 MeV/u carbon ions after traversing different shielding materials (Lucite and aluminium). Whole blood samples, which were either attached to the shielding material (48 mm Lucite or 29 mm aluminium)or positioned at 300 cm away from it at different angles with respect to the beam axis, were exposed to carbon ion beams. For comparison, whole blood samples were exposed directly to 200 MeV/u carbon ions. Chromosomal aberrations in lymphocytes were scored. The results indicated that the biological effectiveness per unit dose was not significantly changed by 48 mm Lucite or 29 mm aluminium, and no significant differences were observed in lymphocytes attached to the target and in lymphocytes positioned at a distance of 300 cm away from the target, at 0º angle of the beam axis. However, when plotted as a function of the number of ions hitting the shielding target, the curves are separated and the shield increases the effectiveness per unit ion. The frequency of chromosomal aberrations at tilted angles behind 29 mm Al and 48 mm Lucite was almost the same. These lesions were considered to be caused by secondary particles due to the passage of particles through the shielding materials.

Biodosimetry estimate for high-LET irradiation

The purpose of this paper is to prepare for an easy and reliable biodosimeter protocol for radiation accidents involving high-linear energy transfer (LET) exposure. Human peripheral blood lymphocytes were irradiated using carbon ions (LET: 34.6 keV microm(-1)), and the chromosome aberrations induced were analyzed using both a conventional colcemid block method and a calyculin A induced premature chromosome condensation (PCC) method. At a lower dose range (0-4 Gy), the measured dicentric (dics) and centric ring chromosomes (cRings) provided reasonable dose information. At higher doses (8 Gy), however, the frequency of dics and cRings was not suitable for dose estimation. Instead, we found that the number of Giemsa-stained drug-induced G2 prematurely condensed chromosomes (G2-PCC) can be used for dose estimation, since the total chromosome number (including fragments) was linearly correlated with radiation dose (r = 0.99). The ratio of the longest and the shortest chromosome length of the drug-induced G2-PCCs increased with radiation dose in a linear-quadratic manner (r = 0.96), which indicates that this ratio can also be used to estimate radiation doses. Obviously, it is easier to establish the dose response curve using the PCC technique than using the conventional metaphase chromosome method. It is assumed that combining the ratio of the longest and the shortest chromosome length with analysis of the total chromosome number might be a valuable tool for rapid and precise dose estimation for victims of radiation accidents.