The efficacy and safety of modified transbronchial cryobiopsy in the diagnosis of interstitial lung disease.

The objective of this study is to investigate the efficacy and safety of flexible transbronchial cryobiopsy (TBCB) in the diagnosis of diffuse parenchymal lung disease (DPLD) in a routine bronchoscopy examination room under analgesia and sedation, using neither endotracheal intubation or rigid bronchoscope nor fluoroscopy or general anesthesia. The data from 50 DPLD patients with unknown etiology who were treated in the Affiliated Hospital of Guilin Medical College from May 2018 to September 2020 were collected, and 43 were eventually included. The specimens obtained from these 43 patients were subjected to pathological examination, pathogenic microorganism culture, etc, and were analyzed in the clinical-radiological-pathological diagnosis mode to confirm the efficacy of TBCB in diagnosing the cause of DPLD. Subsequently, the intraoperative and postoperative complications of TBCB and their severity were closely observed and recorded to comprehensively evaluate the safety of TBCB. For the 43 patients included, a total of 85 TBCB biopsies were performed (1.98 [1, 4] times/case), and 82 valid tissue specimens were obtained (1.91 [1, 4] pieces/case), accounting for 96.5% (82/85) of the total sample. The average specimen size was 12.41 (1, 30) mm2. Eventually, 38 cases were diagnosed, including 11 cases of idiopathic pulmonary fibrosis, 5 cases of connective tissue-related interstitial lung disease, 5 cases of nonspecific interstitial pneumonia, 4 cases of tuberculosis, 4 cases of occupational lung injury, 3 cases of interstitial pneumonia with autoimmune characteristics, 1 case of lung cancer, 2 cases of interstitial lung disease (unclassified interstitial lung disease), 1 case of hypersensitivity pneumonitis, 1 case of pulmonary alveolar proteinosis, and 1 case of fungal infection. The remaining 5 cases were unclarified. For infectious diseases, the overall etiological diagnosis rate was 88.4% (38/43). With respect to complications, pneumothorax occurred in 4 cases (9.3%, 4/43, including 1 mild case and 3 moderate cases), of which 3 cases (75%) were closed by thoracic drainage and 1 case (25%) was absorbed without treatment. In addition, 22 cases experienced no bleeding (51.2%) and 21 cases suffered bleeding to varying degrees based on different severity assessment methods. TBCB is a minimally invasive, rapid, economical, effective, and safe diagnostic technique.

Peripheral blood oxidative stress markers for obstructive sleep apnea-a meta-analysis.

OBJECTIVES: The purpose of this study was to clarify the relationship between obstructive sleep apnea (OSA) and oxidative stress markers in blood. METHODS: We conducted a systematic literature search on databases including Pubmed and Embase for studies reporting circulating oxidative stress markers in patients with OSA and controls that were published between 1988 and June 2019. Standardized mean differences (SMDs) and 95% confidence intervals (95%CI) were calculated. RESULTS: Of the 2226 articles initially retrieved, 52 were included in our meta-analysis, covering a total of 12 oxidative stress markers. The concentrations of malondialdehyde (SMD = 1.18; 95%CI: 0.87, 1.49; p < 0.001), thiobarbituric acid reactive substances (SMD = 1.82; 95%CI: 0.79, 2.86; p = 0.001), advance oxidative protein products (SMD = 0.68; 95%CI: 0.14, 1.23; p = 0.014), total oxidant capacity (SMD = 1.32; 95%CI: 0.33, 2.31; p = 0.009), and asymmetric dimethylarginine (SMD = 0.32; 95%CI: 0.16, 0.47; p < 0.001) in the blood of patients with OSA were higher than those of the control group, whereas the concentrations of thiols (SMD = - 0.37; 95%CI: - 0.60, - 0.15; p = 0.001) and nitric oxide (SMD = - 2.61; 95%CI: - 4.02, - 1.21; p < 0.001) were lower than those of the control group. CONCLUSIONS: The oxidative stress markers in the blood of patients with OSA were aberrant, indicating an imbalanced state of oxidation and antioxidation in OSA.

A meta-analysis on the relationship of exosomes and the prognosis of lung cancer.

BACKGROUND: A lot of research evidence shows that exosomes play an indelible role in the prognosis of lung cancer, but there are many disputes. Therefore, we conduct a meta-analysis to further demonstrate. METHODS: A literature retrieval was performed through a search of PubMed, Embase, Web of Science, Cochrane, CKNI, Wanfang, and other databases to locate documents from the literature that satisfied the inclusion criteria. There were four outcome indicators: overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), and progression-free survival (PFS). Subgroup analysis was conducted according to sample size, country, detection method, analysis method, and pathological type. Stata 14.0 software was used to evaluate the prognostic value of exosomes in lung cancer. RESULTS: A total of 2456 patients with lung cancer from 29 studies in 16 articles were included. The expression level of exosomes was closely associated with the OS and DFS of patients, although no statistical difference was observed between exosomes and DSS or PFS. Eighteen studies with 2,110 patients were evaluated to examine the prognostic value of exosomes in lung cancer by exploring the association between exosomes and OS. The results showed that exosomes were strongly associated with worse OS, and the combined hazard ratio (HR) was 2.01 (95% confidence interval [CI]: 1.70-2.39, P = .000). Six studies investigated the association between exosomes and DFS, and showed a pooled HR of 2.48 (95% CI: 1.75-3.53, P = .000). CONCLUSION: Our analysis indicated that the expression level of exosomes was closely associated with the OS and DFS of patients with lung cancer, suggesting that exosomes are associated with poor prognosis of lung cancer. Exosomes may be a new biomarker for the prognosis of lung cancer, although a large number of prospective studies are still needed to support this.

On the Conditioning of Spectral Channelization (Energy Binning) and Its Impact on Multi-Material Decomposition Based Spectral Imaging in Photon-Counting CT.

OBJECTIVE: The conditioning (well-posedness) of basis materials (functions) and spectral channelization play important roles in determining the performance of spectral imaging (material specific imaging and virtual monochromatic imaging/analysis) in photon-counting CT. Aimed at further understanding the fundamentals of photon-counting spectral CT and providing guidelines on its design and implementation, we propose a singular value decomposition (SVD) and analysis based approach in this work to assess the conditioning of spectral channelization and its impact on the performance of spectral imaging under both ideal and realistic detector spectral response. METHODS: Via simulation studies, in which the geometry of photon-counting CT is similar to a clinical CT, the condition number acquired via SVD and analysis is employed to assess the conditioning of spectral channelization in photon-counting CT and its impact on the performance of spectral imaging. The simulation study runs over two- and three-material decom-position based spectral imaging (material specific imaging and virtual monochromatic imaging/analysis over the energy range [18] [150] keV). Under both ideal and realistic detector spectral response, a specially designed phantom that mimics the soft and bony tissues in the head is utilized to quantitatively reveal the relationship between the conditioning (condition number) of spectral channelization and the performance (mainly noise and contrast-to-noise ratio) of spectral imaging in photon-counting CT. The simulation study is also extended over the cases wherein up to 50% spectral overlapping occurs. RESULTS: The results show that, under ideal detector spectral response, the condition number of spectral channelization reaches the minimum while no overlapping occurs in spectral channels. The condition number of spectral channelization increments with increasing spectral overlapping in the channels. The distortion in detector's spectral response induced by scattering, charge-sharing and fluorescent escaping results in spectral overlapping in spectral channels and thus degrades the conditioning (larger condition number) of spectral channelization. Respectively, the noise increases and contrast-to-noise ratio decreases in material- specific imaging and virtual monochromatic imaging/analysis, while the condition number of spectral channelization increments with increasing spectral overlapping. CONCLUSION: The SVD and analysis based approach can be utilized to systematically analyze the conditioning of spectral channelization and its impact on the performance of spectral imaging in photon-counting CT. SIGNIFICANCE: The approach proposed by us brings innovation and has significance. In addition to providing information for insightful understanding of the fundamentals, the approach proposed in this study and the data obtained so far may provide guidelines on the implementation of spectral imaging in photon-counting CT and energy-integration CT as well, along with its applicability to other x-ray related imaging modalities such as radiography and tomosynthesis.

Principal Component Analysis in Projection and Image Domains-Another Form of Spectral Imaging in Photon-Counting CT.

OBJECTIVE: We explore the feasibility of principal component analysis (PCA) as a form of spectral imaging in photon-counting CT. METHODS: Using the data acquired by a prototype system and simulated by computer, we investigate the feasibility of spectral imaging in photon-counting CT via PCA for feature extraction and study the impacts made by data standardization and de-noising on its performance. RESULTS: The PCA in the projection domain maintains the data consistence that is essential for tomographic image reconstruction and performs virtually the same as that in the image domain. The first three primary components account for more than 99.99% covariance of the data. Within anticipation, the contrast-to-noise ratio (CNR) between the target and background in the first principal component image can be larger than that in the image generated from the data acquired in each energy bin. More importantly, the CNR in the first principal component image may be larger than that in the image formed by the summed data acquired in all energy bins (i.e., the conventional polychromatic CT image). In addition, de-noising can not only reduce the noise in images but also improve the effectiveness/efficiency of PCA in feature extraction. CONCLUSION: The PCA in either projection or image domain provides another form of spectral imaging in photon-counting CT that fits the essential requirements on spectral imaging in true color. SIGNIFICANCE: The verification of PCA's feasibility in CT as a form spectral imaging and observation of its potential superiority in CNR over conventional polychromatic CT are meaningful in theory and practice.