维生素C对香烟烟雾的氧化应激作用的影响

目的　了解维生素C(VC)对香烟烟雾溶液 (CSS)作用下的大鼠淋巴细胞产生氧化应激的影响。方法　将香烟烟雾溶液作用于经VC预处理的大鼠淋巴细胞 ,用 2’ ,7’ -二乙酰二氯荧光素 (DCFH -DA)检测细胞内活性氧自由基 (ROS)水平 ,用彗星实验评价DNA的损伤状况 ,同时检测细胞内超氧化物歧化酶 (SOD)活性和脂质过氧化物(LPO)水平。结果　 8× 10 -3 支 /mlCSS作用下大鼠淋巴细胞内ROS和LPO水平增高 ,DNA损伤增强 ,SOD活性降低。用 5 0 μmol/LVC干预后 ,与相应非干预组相比细胞内ROS和LPO水平降低 ,DNA损伤减轻 ,SOD活性增强 ,且均有显著性差异。结论　 5 0 μmol/LVC能保护大鼠淋巴细胞 ,减轻CSS导致的氧化应激。     

计算机图像处理技术在舌像特征提取中的应用

本文综合运用数字图像处理和计算机视觉技术,应用VC++开发环境和Matlab程序设计语言,以舌像为具体研究对象,通过舌形、颜色、边缘、纹理等表面特征的提取与分析,研究计算机图像处理技术在舌像特征提取中的应用.开发的软件功能齐全,界面友好,使用方便.本文为中医舌像的模式识别提供了特征数据,是下一步对舌像进行识别的基础.     

Predicting healthcare expenditure by multimorbidity groups

Objectives

This article has two main purposes. Firstly, to model the integrated healthcare expenditure for the entire population of a health district in Spain, according to multimorbidity, using Clinical Risk Groups (CRG). Secondly, to show how the predictive model is applied to the allocation of health budgets.

Monitoring recovery from diaphragm paralysis with ultrasound

BACKGROUND: Diaphragmatic paralysis is an uncommon, yet underdiagnosed cause of dyspnea. Data regarding the time course and potential for recovery has come from a few small case series. The methods that have been traditionally employed to diagnose diaphragmatic weakness or paralysis are either invasive or limited in sensitivity and specificity. A new technique utilizing two-dimensional, B-mode ultrasound (US) measurements of diaphragm muscle thickening during inspiration (Deltatdi%) has been validated in the diagnosis of diaphragm paralysis (DP). The purpose of this study was to assess whether serial US evaluation might be utilized to monitor the potential recovery of diaphragm function. METHODS: Twenty-one consecutive patients with clinically suspected DP were referred to the pulmonary physiology laboratory. Sixteen patients were found to have DP by US (unilateral, 10 patients; bilateral, 6 patients). Subjects were followed up for up to 60 months. On initial and subsequent visits, Deltatdi% was measured by US. Additional measurements included upright and supine vital capacity (VC), maximal inspiratory pressure (Pimax), and maximal expiratory pressure. RESULTS: Eleven of 16 patients functionally recovered from DP. The mean (+/- SD) recovery time was 14.9 +/- 6.1 months. No diaphragm thickening was noted in those patients who did not recover. Positive correlations were found between improvement in Deltatdi% and interval changes in VC, Pimax, and end-expiratory measurements of diaphragm thickness. CONCLUSIONS: US may be used to assess for potential functional recovery from diaphragm weakness or DP. As in previous series, recovery occurs in a substantial number of individuals, but recovery time may be prolonged.     

Acute Effects of Individual Exposure to Fine Particulate Matter on Pulmonary Function in Schoolchildren

Objective This panel study aimed to determine the acute effects of exposure to fine particulate matter(PM_(2.5)) on schoolchildren's pulmonary function.Methods We selected 51 schoolchildren aged 9–12 years attending a full-time boarding school in Beijing, China, measured the indoor and outdoor PM_(2.5) concentrations for five consecutive days,calculated the PM_(2.5) time-weighted individual exposure levels based on the school micro-environmental concentrations and the time activity pattern recorded by schoolchildren, measured schoolchildren's pulmonary function on the fifth day. The survey was performed three times from December 2018 to April 2019. We used a linear mixed-effects model to evaluate the associations between PM_(2.5) and pulmonary function.Results During the three surveys, the median PM_(2.5) time-weighted individual exposure concentrations were 15.30 μg/m3, 48.92 μg/m3, and 42.89 μg/m3, respectively. There was a significant difference between the three surveys in vital capacity(VC), forced vital capacity(FVC), forced expiratory volume in one second(FEV_1) and forced expiratory volume in one second/forced vital capacity(FEV1/FVC)(P 0.05). The relevance analysis found that PM_(2.5) had lag effect on schoolchildren's pulmonary function,each 10 μg/m~3 increase in PM_(2.5) could cause largest decreases in FEF25%–75%, FEV_1/FVC, FEF75%, and FEV1 on lag 0–1 d(80.44 m L/s, 35.85%, 78.58 m L/s, and 61.34 m L, respectively), and largest decreases in FEF25% on lag 1 d(83.68 m L/s), in VC on lag 4 d(32.34 m L), and in FVC on lag 0–4 d(37.76 m L). Gender subgroup analysis revealed that the increase in PM_(2.5) caused a decrease in FEV_1/FVC and VC on the day of physical examination only in boys, and on lag days it caused changes in different pulmonary function indicators, both for boys and girls, but most of the pulmonary function indicators decreased more in boys than in girls.Conclusion Our findings show that acute PM_(2.5) exposure has significant effects on pulmonary function within 0–4 d, on both small airway indicators and large airway indicators. Boys' pulmonary function is more sensitive to PM_(2.5) than girls.     

Diagnosis and prognostic value of restrictive ventilatory disorders in the elderly: a systematic review of the literature

Although less extensively studied compared to pulmonary obstructive diseases, restrictive lung disease (RLD) is highly prevalent and frequently disabling in the adult and, more, the elderly population. The underlying conditions may be either primarily pulmonary diseases, such as idiopathic pulmonary fibrosis, or non respiratory conditions secondarily affecting the lung, e. g. congestive heart failure, or else conditions affecting the lung expansion, e. g. obesity or rib cage deformity. The diagnosis is frequently based on the measurement of surrogate indexes such as the forced vital capacity (FVC) used as a proxy for total lung capacity (TLC). As a consequence, diagnosis of RLD is often characterized by poor specificity. In the elderly, worsening in the quality of life and poor prognosis are variably, but significantly, associated to RLD, being the underlying condition an important source of variability. Several causes of RLD are preventable and treatable conditions. A prompt identification of these conditions may allow to slow the decline of respiratory reserve and, thus, to preserve both personal independence and resistance to acute respiratory infections. This review gives an update on the latest evidence available on the prevalence and the prognosis of RLD in the elderly. Studies were identified through systematic searches of the electronic database MEDLINE. Reference list of eligible papers were also manually searched.     

Peak Cough Flow Fails to Detect Upper Airway Collapse During Negative Pressure Titration for Cough-Assist

ObjectiveTo study the ability of peak cough flow (PCF) and effective cough volume, defined as the volume exsufflated >3 L/s, to detect upper airway collapse during mechanical insufflation-exsufflation (MI-E) titration in neuromuscular patients.DesignProspective observational study.SettingRehabilitation hospital.ParticipantsPatients (N=27) with neuromuscular disease causing significant impairment of chest wall and/or diaphragmatic movement.InterventionsThe lowest insufflation pressure producing the highest inspiratory capacity was used. Exsufflation pressure was decreased from ?20 cm H₂O to ?60/?70 cm H₂O, in 10-cm H₂O decrements, until upper airway collapse was detected using the reference standard of flow-volume curve analysis (after PCF, abrupt flattening or flow decrease vs previous less negative exsufflation pressure).Main Outcome MeasuresPCF and effective cough volume profiles during expiration with MI-E.ResultsUpper airway collapse occurred in 10 patients during titration. Effective cough volume increased with decreasing expiratory pressure then decreased upon upper airway collapse occurrence. PCF continued to increase after upper airway collapse occurrence. In 5 other patients, upper airway collapse occurred at the initial ?20 cm H₂O exsufflation pressure, and during titration, PCF increased and effective cough volume remained unchanged at <200 mL. PCF had 0% sensitivity for upper airway collapse, whereas effective cough volume had 100% sensitivity and specificity.ConclusionOf 27 patients, 15 experienced upper airway collapse during MI-E titration. Upper airway collapse was associated with an effective cough volume decrease or plateau and with increasing PCF. Accordingly, effective cough volume, but not PCF, can detect upper airway collapse.