[Dynamic variation trend and prognostic value of bronchial wall thickness in severely burned patients combined with inhalation injury].

Objective: To explore the dynamic variation trend of bronchial wall thickness (BWT) in severely burned patients combined with inhalation injury, and to determine the value of BWT to prognosis of patients. Methods: Forty-three severely burned patients with inhalation injury hospitalized in Intensive Burn Department of the Affiliated Hospital of Nankai University (Tianjin No.4 Hospital) from July to November 2016, conforming to the study criteria, were divided into survival group (n=27) and death group (n=16) according to the prognosis of patients within 14 days after admission. All patients underwent fiberoptic bronchoscopy and inhalation injury rating based on abbreviated injury scale at admission. High resolution CT examination was performed in patients of two groups at admission and 24 h post admission, 3, 7, and 14 d post admission to measure the BWT of right superior lobar bronchus trunk opening. Receiver operating characteristic curves of rating of inhalation damage at admission and BWT at admission were drawn to evaluate the predictive value for death of 43 patients. Data were processed with chi-square test, independent sample t test, Wilcoxon rank sum test, analysis of variance for repeated measurement and least-significant difference-t test. Results: (1) The numbers of patients rated as 0, 1, 2, 3, and 4 grade for inhalation injury in survival group and death group were 0, 19, 6, 2, and 0, and 0, 2, 7, 7, and 0, respectively. There were statistically significant differences between the two groups (Z=-3.79, P<0.01). (2) BWT of patients in death group at admission and 24 h post admission, 3, 7, and 14 d post admission was respectively (2.72±0.26), (3.18±0.22), (2.98±0.18), (2.29±0.17), and (1.45±0.21) mm, which was significantly larger than (2.24±0.15), (2.49±0.15), (1.51±0.17), (1.04±0.16), and (1.01±0.13) mm in survival group (t=7.55, 12.14, 27.11, 19.99, 7.11, P<0.01). BWT of patients in survival group and death group at 24 h post admission, 3, 7, and 14 d post admission showed statistically significant difference when compared with that at admission within the corresponding group (t=5.97, 16.63, 28.21, 38.57, 5.34, 3.31, 4.39, 6.48, P<0.01). BWT of patients in survival group and death group on 3, 7, and 14 d post admission was significantly smaller than that at 24 h post admission within the corresponding group (t=22.27, 34.02, 45.03, 2.77, 10.53, 10.59, P<0.01). BWT of patients in survival group and death group on 7 and 14 d post admission was significantly smaller than that on 3 d post admission within the corresponding group (t=10.49, 18.26, 9.57, 11.44, P<0.01). BWT of patients in survival group and death group on 14 d post admission was significantly smaller than that on 7 d post admission within the corresponding group (t=6.97, 6.15, P<0.01). (3) The total areas under ROC curves of inhalation injury rating at admission and BWT at admission for predicting death of 43 patients were 0.880 and 0.956, respectively (with 95% confidence intervals 0.768-0.991, 0.882-1.000, P<0.05). Grade 1.5 and 2.75 mm were respectively chosen as the optimal threshold values of inhalation injury rating at admission and BWT at admission, with sensitivity of 87.50%, 83.33% and specificity of 77.78%, 96.00%, respectively. Conclusions: The BWT of survived and dead patients with severe burn and inhalation injury increases significantly post burn, while the BWT of survived patients restores to normal level faster. BWT can be used to assess the severity of inhalation injury and to predict death in severely burned patients combined with inhalation injury.

Growth of cortical neuronal network in vitro: modeling and analysis.

We present a detailed analysis and theoretical growth models to account for recent experimental data on the growth of cortical neuronal networks in vitro [Phys. Rev. Lett. 93, 088101 (2004)]. The experimentally observed synchronized firing frequency of a well-connected neuronal network is shown to be proportional to the mean network connectivity. The growth of the network is consistent with the model of an early enhanced growth of connection, but followed by a retarded growth once the synchronized cluster is formed. Microscopic models with dominant excluded volume interactions are consistent with the observed exponential decay of the mean connection probability as a function of the mean network connectivity. The biological implications of the growth model are also discussed.

Connectivities and synchronous firing in cortical neuronal networks.

Network connectivities ((-)k) of cortical neural cultures are studied by synchronized firing and determined from measured correlations between fluorescence intensities of firing neurons. The bursting frequency (f) during synchronized firing of the networks is found to be an increasing function of (-)k. With f taken to be proportional to (-)k, a simple random model with a (-)k dependent connection probability p((-)k).has been constructed to explain our experimental findings successfully.