Portable spirometers has been approved for diagnosing chronic obstructive pulmonary disease (COPD). However, their diagnostic accuracy has not been reviewed. Therefore, the purpose of this study was to systematically evaluate the diagnostic value of portable spirometers in detecting COPD. A comprehensive literature search for relevant studies was conducted in PubMed, Embase, CNKI, Wan Fang, and Web of Science databases. Pooled sensitivity, specificity, summary receiver operating characteristic (SROC), area under the curve (AUC), and other related indices were calculated using the bivariate mixed-effect model. Subgroup analysis was performed to explore the source of heterogeneity. Thirty one studies were included in the meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic ratio (DOR), SROC, and AUC of the SROC of portable spirometers were 0.85 (0.81–0.88), 0.85 (0.81–0.88), 5.6 (4.4–7.3), 0.18 (0.15–0.22), 31 (21–46) and 0.91 (0.89–0.94), respectively. Among the three commonly used types of portable spirometers, the accuracy of PIKO-6 was higher (0.95) than that of COPD-6 (0.91) and PEF (0.82). Subgroup analysis indicated that the accuracy of a multi-indices portable spirometer was higher than that of a single-index one (P < 0.05). In addition, portable spirometry performed by professional technicians in tertiary hospitals was more accurate than for those conducted by trained technicians in primary care facilities and communities (P < 0.05). Moreover, the accuracy of studies conducted in developing country was superior to developed country (P < 0.05). Portable spirometers have high accuracy in the diagnosis of COPD. Multi-index COPD-6 and PIKO-6 displayed higher accuracy than others. Standardized training of instrument operators should be considered to achieve reliable results.

Background: Human adipose-derived stem cells (hADSCs) are stem cells with the potential to differentiate in multiple directions. miR-204-5p is expressed at low levels during the osteogenic differentiation of hADSCs, and its specific regulatory mechanism remains unclear. Here, we aimed to explore the function and possible molecular mechanism of miR-204-5p in the osteogenic differentiation of hADSCs. Methods: The expression patterns of miR-204-5p, Runx2, alkaline phosphatase (ALP), osteocalcin (OCN), forkhead box C1 (FOXC1) and growth differentiation factor 7 (GDF7) in hADSCs during osteogenesis were detected by qRT-PCR. Then, ALP and alizarin red staining (ARS) were used to detect osteoblast activities and mineral deposition. Western blotting was conducted to confirm the protein levels. The regulatory relationship among miR-204-5p, FOXC1 and GDF7 was verified by dual-luciferase activity and chromatin immunoprecipitation (ChIP) assays. Results: miR-204-5p expression was downregulated in hADSC osteogenesis, and overexpression of miR-204-5p suppressed osteogenic differentiation. Furthermore, the levels of FOXC1 and GDF7 were decreased in the miR-204-5p mimics group, which indicates that miR-204-5p overexpression suppresses the expression of FOXC1 and GDF7 by binding to their 3′-untranslated regions (UTRs). Overexpression of FOXC1 or GDF7 improved the inhibition of osteogenic differentiation of hADSCs induced by the miR-204-5p mimics. Moreover, FOXC1 was found to bind to the promoter of miR-204-5p and GDF7, promote the deacetylation of miR-204-5p and reduce the expression of miR-204-5p, thus promoting the expression of GDF7 during osteogenic differentiation. GDF7 induced hADSC osteogenesis differentiation by activating the AKT and P38 signalling pathways. Conclusions: Our results demonstrated that the miR-204-5p/FOXC1/GDF7 axis regulates the osteogenic differentiation of hADSCs via the AKT and p38 signalling pathways. This study further revealed the regulatory mechanism of hADSC differentiation from the perspective of miRNA regulation.

Purpose: Chronic obstructive pulmonary disease (COPD) is under diagnosis in China. This study aimed to evaluate the accuracy of six COPD screening questionnaires for the early detection of COPD. Patients and Methods: We recruited patients aged ≥ 35 years, presenting at the First Affiliated Hospital of China Medical University in 2021. All participants completed the COPD Diagnostic Questionnaire (CDQ), Revised COPD Diagnostic Questionnaire (Revised-CDQ), COPD Population Screener (COPD-PS), COPD Screening Questionnaire (COPD-SQ), COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE), and Lung Function Questionnaire (LFQ). The patients underwent spirometry testing with further bronchodilator testing for those with FEV₁/FVC values of < 0.70. Receiver operating characteristic curves (ROC) were drawn for each questionnaire. The sensitivity, specificity, positive predictive (PPV), negative predictive (NPV), and area under the curve (AUC) values of the optimal cut-off and previously reported scores were estimated and compared. Results: Of 909 patients who completed the six screening questionnaires and spirometry testing, 330 patients were newly diagnosed with COPD. AUC values for the LFQ, Revised CDQ, COPD-PS, CDQ, COPD-SQ, and CAPTURE were 0.785 (95% confidence interval: 0.752– 0.812), 0.762 (0.727– 0.795), 0.745 (0.707– 0.778), 0.731 (0.695– 0.762), 0.703 (0.671– 0.734), and 0.667 (0.635– 0.702), respectively. The optimal cut-off scores for CDQ, Revised-CDQ, COPD-PS, COPD-SQ, CAPTURE, and LFQ were: 19, 19, 5, 17, 3, and 16 points, respectively. Compared with the previously recommended values, the present cut-off values for the CAPTURE and LFQ had better screening accuracy. The LFQ performed better than the CDQ, COPD-SQ, or CAPTURE. The Revised CDQ performed better than CAPTURE or COPD-SQ. The COPD-PS performed better than CAPTURE. Conclusion: All six questionnaires can discriminate between subjects with or without COPD. The LFQ performed particularly well. The CAPTURE and LFQ scores of 3 and 16 have better screening accuracy than the scores previously reported.