A Semiautomatic Segmentation Algorithm for Extracting the Complete Structure of Acini from Synchrotron Micro-CT Images

Pulmonary acinus is the largest airway unit provided with alveoli where blood/gas exchange takes place. Understanding the complete structure of acinus is necessary to measure the pathway of gas exchange and to simulate various mechanical phenomena in the lungs. The usual manual segmentation of a complete acinus structure from their experimentally obtained images is difficult and extremely time-consuming, which hampers the statistical analysis. In this study, we develop a semiautomatic segmentation algorithm for extracting the complete structure of acinus from synchrotron micro-CT images of the closed chest of mouse lungs. The algorithm uses a combination of conventional binary image processing techniques based on the multiscale and hierarchical nature of lung structures. Specifically, larger structures are removed, while smaller structures are isolated from the image by repeatedly applying erosion and dilation operators in order, adjusting the parameter referencing to previously obtained morphometric data. A cluster of isolated acini belonging to the same terminal bronchiole is obtained without floating voxels. The extracted acinar models above 98% agree well with those extracted manually. The run time is drastically shortened compared with manual methods. These findings suggest that our method may be useful for taking samples used in the statistical analysis of acinus

Biphasic and directed translocation of protein kinase Cα inside cultured endothelial cells before migration

Mechanical wounding of an endothelial monolayer induces an immediate Ca2+ wave. Several hours later, the denuded area is covered by endothelial cells (ECs) that migrate to the wound. This migration process is closely related to protein kinase Cα (PKCα), a Ca2+-dependent protein that translocates from the cytosol to the cell membrane. Because the cells adjacent to the wounded area are the first to migrate into the wound, we investigated whether a mechanical wound immediately induces PKCα translocation in adjacent cells. We monitored Ca2+ dynamics and PKCα translocation simultaneously using fluorescent microscopy. For this simultaneous observation, we used Fura-2–acetoxymethyl ester to visualize Ca2+ and constructed a green fluorescent protein-tagged fusion protein to visualize PKCα. Mechanical wounding of the endothelial monolayer induced an immediate Ca2+ wave in cells adjacent to the wounded cells before their migration. Almost concurrently, PKCα in the neighboring cells translocated to the cell membrane, then accumulated at the periphery near the wounded cell. This report is the first description of this biphasic and directed translocation of PKCα in cells before cell migration. Our results may provide new insights into the directed migration of ECs

Statistical resolutions for large variabilities in hair mineral analysis

Measuring biomaterials is usually subject to error. Measurement errors are classified into either random errors or biases. Random errors can be well controlled using appropriate statistical methods. But, biases due to unknown, unobserved, or temporary causes, may lead to biased conclusions. This study describes a verification method to examine whether measurement errors are random or not and to determine efficient statistical methods.A number of studies have dealt with associations between hair minerals and exposures such as health,dietary or environmental conditions. Most review papers, however,emphasize the necessity for validation of hair mineral measurements, since large variations can cause highly variable results. To address these issues, we answer the following questions: 1. How can we ascertain the reliability of measurements? 2. How can we assess and control the variability of measurements? 3. How do we efficiently determine associations between hair minerals and exposures? 4. How can we concisely present the reference values? Since hair minerals all have distinctive natures, it would be unproductive to examine each mineral individually to find significant and consistent answers that apply to all minerals. To surmount this difficulty, we used one simple model for all minerals to explore quantitative answers.Hair mineral measurements of six-year-old children were analyzed based on the statistical model. The analysis verified that most of the measurements were reliable, and their inter-individual variations followed two-parameter distributions. These results allow for sophisticated study designs and efficient statistical methods to examine the effects of various kinds of exposures on hair minerals

Pre-hospital airway management and neurological status of patients with out-of-hospital cardiac arrest: A retrospective cohort study

Purpose: Little is known about whether pre-hospital advanced airway management (AAM) under the presence of a physician could improve outcome of patients with cardiac arrest, compared with pre-hospital AAM under the absence of a physician. Methods: This retrospective multicentre-cohort study enrolled consecutive patients who were transported to participating hospitals after out-of-hospital cardiac arrest in Japan between 1 June 2014 and 31 December 2019. We included patients who underwent pre-hospital AAM and resuscitation after arrival at hospital, and who were ≥18 years of age, with medical aetiologies. The primary outcome was favourable neurological survival (Cerebral Performance Category score of 1 or 2) one month after cardiac arrest. The primary outcome was called one-month favourable neurological survival. The first confirmed cardiac rhythm was defined using 3-lead electrocardiogram monitor or an automated external defibrillator and by determining whether the carotid artery was pulsating. Previous research found that the presence of a pre-hospital physician was associated with improved patients’ outcomes, after the type of first confirmed cardiac rhythm was considered. Therefore, the first confirmed cardiac rhythm in current study was subdivided into non-shockable or shockable groups. A multivariable logistic regression analysis was performed on propensity score-matched patients. Results: We analysed 16,703 patients. Among the 2,346 patients in the non-shockable group, 1.2% (N = 29) achieved the primary outcome. The adjusted odds ratio of pre-hospital AAM with or without a physician for the primary outcome in the results of the non-shockable group was 4.64 (95% confidence interval: 1.81–14.4). Among the 826 patients in the shockable group, 16.9% (N = 140) achieved the primary outcome and the adjusted odds ratio of pre-hospital AAM with or without a physician for the primary outcome in the results of the shockable group was 1.05 (95% confidence interval: 0.67–1.63). Conclusions: This retrospective multicentre-cohort study found that pre-hospital AAM under the presence of a physician was significantly associated with increased neurological outcome in specific patients with cardiac arrest, compared with pre-hospital AAM under the absence of a physician