A deep learning-based algorithm for pulmonary tuberculosis detection in chest radiography.

In tuberculosis (TB), chest radiography (CXR) patterns are highly variable, mimicking pneumonia and many other diseases. This study aims to evaluate the efficacy of Google teachable machine, a deep neural network-based image classification tool, to develop algorithm for predicting TB probability of CXRs. The training dataset included 348 TB CXRs and 3806 normal CXRs for training TB detection. We also collected 1150 abnormal CXRs and 627 normal CXRs for training abnormality detection. For external validation, we collected 250 CXRs from our hospital. We also compared the accuracy of the algorithm to five pulmonologists and radiological reports. In external validation, the AI algorithm showed areas under the curve (AUC) of 0.951 and 0.975 in validation dataset 1 and 2. The accuracy of the pulmonologists on validation dataset 2 showed AUC range of 0.936-0.995. When abnormal CXRs other than TB were added, AUC decreased in both human readers (0.843-0.888) and AI algorithm (0.828). When combine human readers with AI algorithm, the AUC further increased to 0.862-0.885. The TB CXR AI algorithm developed by using Google teachable machine in this study is effective, with the accuracy close to experienced clinical physicians, and may be helpful for detecting tuberculosis by CXR.

Clinical Characteristics and Predictors of Mortality in Critically Ill Adult Patients with Influenza Infection.

Patients with influenza infection may develop acute respiratory distress syndrome (ARDS), which is associated with high mortality. Some patients with ARDS receiving extracorporeal membrane oxygenation (ECMO) support die of infectious complications. We aimed to investigate the risk factors affecting the clinical outcomes in critically ill patients with influenza. We retrospectively reviewed the medical records of influenza patients between January 2006 and May 2016 at the Kaohsiung Veterans General Hospital in Taiwan. Patients aged below 20 years or without laboratory-confirmed influenza were excluded. Critically ill patients who presented with ARDS (P = 0.004, odds ratio (OR): 8.054, 95% confidence interval (CI): 1.975-32.855), a higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (P = 0.008, OR: 1.102, 95% CI: 1.025-1.184), or higher positive end-expiratory pressure (P = 0.008, OR: 1.259, 95% CI: 1.061-1.493) may have a higher risk of receiving ECMO. Influenza A (P = 0.037, OR: 0.105, 95% CI: 0.013-0.876) and multiple organ failure (P = 0.007, OR: 0.056, 95% CI: 0.007-0.457) were significantly associated with higher mortality rates. In conclusion, our study showed critically ill influenza patients with ARDS, higher APACHE II scores, and higher positive end-expiratory pressure have a higher risk of receiving ECMO support. Influenza A and multiple organ failure are predictors of mortality.

Changes in voltage-dependent calcium channel currents of vascular smooth muscle cells isolated from small mesenteric arteries of simulated weightless rats / 生理学报

The aim of the present study was to examine the changes in the function of voltage-dependent calcium channels (VDC) of vascular smooth muscle cells (VSMCs) isolated from small mesenteric arteries of rats subjected to 1-week or 4-week simulated weightlessness. The whole-cell recording mode was used to record current densities and Ba(2+) was used as charge carrier. Curves and fitting parameters describing steady-state activation and inactivation characteristics of VDC were thus obtained. The inward currents recorded from the VSMCs of small mesenteric arteries were mainly the Ba(2+) currents through the long-lasting type VDC (L-VDC). Compared with that of the control rats, the L-VDC current density of VSMCs from small mesenteric arteries showed a trend toward a decrease in the rats after 1-week , while a significant decrease was observed in the rats after 4-week simulated weightlessness. However, there were no significant differences in the opening and closing rates of L-VDCs, the position of steady-state activation and inactivation curves, and in the parameters, V(0.5) and k, between either of the two groups and its respective control group. The membrane capacitance and the reversal potential of the VSMCs from the small mesenteric arteries of rats after simulated weightlessness also showed no significant changes. These findings suggest that the decreased function of the L-VDC in hindquarter VSMCs might be one of the electrophysiological mechanisms that mediate the depressed vasoreactivity and atrophic change in hindquarter arteries during adaptation to simulated weightlessness in rats.

Enhanced BK(Ca) single-channel activities in cerebrovascular smooth muscle cells of simulated microgravity rats / 生理学报

The aim of the present study was to investigate the changes in single-channel currents of large conductance calcium-activated potassium channels (BK(Ca) channels) in cerebral vascular smooth muscle cells (VSMCs) of rats after 1-week simulated microgravity. Sprague-Dawley rats were subjected to tail-suspension (SUS) to simulate cardiovascular deconditioning due to microgravity. Cytosolic calcium ([Ca(2+)](i)) was examined by laser-scanning confocal microscopy with calcium-sensitive-dye Fluo-3/AM as fluorescent probe. Single-channel currents of BK(Ca) channels were measured with cell-attached membrane patches bathed in symmetrical high potassium solution. The [Ca(2+)](i)i level was significantly higher in cerebrovascular myocytes of SUS than that of control (CON) rats. The probability of open (Po) and the mean open time (To) of BK(Ca) channels in cerebral VSMCs significantly increased in SUS as compared with CON. However, there were no significant differences in the unitary conductance and mean close time (Tc) between the two groups. The results obtained suggest that both the elevated [Ca(2+)](i) and enhanced single-channel activities of BK(Ca) channels in cerebral VSMCs might be among the electrophysiological mechanisms that mediate the increased vasoreactivity and hypertrophic change in cerebral arteries during adaptation to simulated microgravity in rats.

Changes in potassium currents of vascular smooth muscle cells isolated from hindquarter arteries of rats after 4 weeks simulated weightlessness / 生理学报

The changes in potassium currents of vascular smooth muscle cells (VSMCs) isolated from saphenous arteries and the 2nd-6th order branches of the mesenteric arteries of 4-week tail-suspended rats (SUS) were examined using whole cell patch clamp technique. The resting potential (RP) of the VSMCs from SUS group was more negative compared with that of the control group (CON).The whole cell potassium current densities of VSMCs isolated from the saphenous arteries and small mesenteric arteries in SUS group were significantly larger than those of the CON group.The BK(Ca) and K(V) current densities of VSMCs from saphenous arteries and small mesenteric arteries from SUS group were also significantly larger than those from the CON group.It is speculated that the hyperpolarization of VSMCs and decreased calcium influx through voltage-dependent calcium channels might be one of the electrophysiological mechanisms involved in the depressed vasoreactivity of hindquarter arteries induced by simulated weightlessness.