Spirometric Reference Equations for Elderly Chinese in Jinan Aged 60-84 Years / 中华医学杂志(英文版)

<p><b>Background</b>The interpretation of spirometry varies on different reference values. Older people are usually underrepresented in published predictive values. This study aimed at developing spirometric reference equations for elderly Chinese in Jinan aged 60-84 years and to compare them to previous equations.</p><p><b>Methods</b>The project covered all of Jinan city, and the recruitment period lasted 9 months from January 1, 2017 to September 30, 2017, 434 healthy people aged 60-84 years who had never smoked (226 females and 208 males) were recruited to undergo spirometry. Vital capacity (VC), forced VC (FVC), forced expiratory volume in 1 s (FEV), FEV/FVC, FEV/VC, FEV, peak expiratory flow, and forced expiratory flow at 25%, 50%, 75%, and 25-75% of FVC exhaled (FEF, FEF, FEF, and FEF) were analyzed. Reference equations for mean and the lower limit of normal (LLN) were derived using the lambda-mu-sigma method. Comparisons between new and previous equations were performed by paired t-test.</p><p><b>Results</b>New reference equations were developed from the sample. The LLN of FEV/FVC, FEFcomputed using the 2012-Global Lung Function Initiative (GLI) and 2006-Hong Kong equations were both lower than the new equations. The biggest degree of difference for FEV/FVC was 19% (70.46% vs. 59.29%, t = 33.954, P < 0.01) and for maximal midexpiratory flow (MMEF, equals to FEF) was 22% (0.82 vs. 0.67, t = 21.303, P < 0.01). The 1990-North China and 2009-North China equations predicted higher mean values of FEV/FVC and FEFthan the present model. The biggest degrees of difference were -4% (78.31% vs. 81.27%, t = -85.359, P < 0.01) and -60% (2.11 vs. 4.68, t = -170.287, P < 0.01), respectively.</p><p><b>Conclusions</b>The newly developed spirometric reference equations are applicable to elderly Chinese in Jinan. The 2012-GLI and 2006-Hong Kong equations may lead to missed diagnoses of obstructive ventilatory defects and the small airway dysfunction, while traditional linear equations for all ages may lead to overdiagnosis.</p>

Thrombin promotes human lung fibroblasts to proliferate via NADPH oxidase/reactive oxygen species/extracellular regulated kinase signaling pathway / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Thrombin is a multifunctional serine protease that plays a crucial role in hemostasis following tissue injury. In addition to its procoagulation effect, thrombin is also a potent mesenchymal cell mitogen, therefore it plays important roles in the local proliferation of mesenchymal cells in the tissue repair process. Reactive oxygen species (ROS) can induce some human cells to proliferate at lower rates while at higher concentrations they promote cells to undergo apoptosis or necrosis. Accumulative evidence suggests that thrombin can induce some cells to produce ROS. Based on these observations, we provide a hypothesis that thrombin can stimulate human lung fibroblasts to produce ROS, which play an important role in human lung fibroblast proliferation.</p><p><b>METHODS</b>ROS were detected in fibroblasts at 30 minutes and 60 minutes following thrombin (20 U/ml) exposure using flow cytometry. The ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) was assayed in lung fibroblasts using a commercial kit following treatment with thrombin at different concentrations. NADPH oxidase and the extracellular regulated kinase1/2 (ERK1/2) signaling pathway were detected by Western blotting after thrombin stimulation to lung fibroblasts.</p><p><b>RESULTS</b>Thrombin, at 20 U/ml, stimulated human lung fibroblasts (HLF) to generate ROS in a time dependent manner. The ratio of GSH/GSSG in fibroblasts treated with thrombin showed a significant decrease. NADPH oxidase was activated and the ERK1/2 signal pathway was involved in the proliferation process of fibroblasts treated with thrombin.</p><p><b>CONCLUSION</b>The activation of NADPH oxidase by thrombin leads to the production of ROS, which promotes fibroblasts proliferation via activation of the ERK1/2 signaling pathway.</p>

Predominant aciduric microflora related to fissure caries of the first permanent molars / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the aciduric bacteria in different stages of the fissure caries in order to determine potential roles of the microflora in the development of dental caries.</p><p><b>METHODS</b>Plaque samples were taken from 10 incipient carious fissures of the first permanent molars. Plaque samples were also collected from sound fissures of the first permanent molars in 10 other subjects who kept caries free over the past 2 years and from the above 10 subjects. The predominant bacteria were isolated by using both the most probable method in media at pH7.0 and 5.2, and the conventional plating methods. Streptococcus spp. was identified by means of API 20 Strep commercial kit.</p><p><b>RESULTS</b>S. mutans was the predominant aciduric bacteria infissures of caries-free children and more frequently recovered at neutral pH. Whilst, S. sanguis was predominant at pH5.2 in sound and carious of fissures of caries-active children. The proportion of Gram-positive rods at pH5.2 was 82%, significantly greater than that of 61% at pH7.0.</p><p><b>CONCLUSION</b>The ecology of plaque is complex and the composition of microflora at each stage of caries could be different. The composition of bacteria was consistent with the changes of local pH in the plaque.</p>