[Clinical research progress in non-invasive positive pressure ventilation in 2023]

Non-invasive positive pressure ventilation (NPPV) is a widely used method of providing respiratory support in a variety of clinical settings, including emergency departments, general wards, and intensive care units. The relevant research articles on NPPV published between 1st October 2022 and 30th September 2023 were retrieved from Medline and reviewed. In the management of acute respiratory failure (ARF) associated with COVID-19, studies have highlighted the significant influence of regional economic status on the choice of respiratory support strategies. It has been observed that NPPV is more suitable for patients with mild to moderate acute respiratory distress syndrome (ARDS) than for those with severe ARDS, as the latter group has an increased risk of delayed intubation. In addition, patients with severe dyspnea tended to benefit more from NPPV compared with high flow nasal cannula (HFNC) and conventional oxygen therapy, with a reduced risk of self-induced lung injury. For non-COVID-19-related ARF, research shows no significant differences in mortality and intubation rates between HFNC and NPPV in patients with hypercapnic ARF. The updated HACOR score and ROX score have been validated to have a high predictive value for clinical outcomes in patients receiving NPPV for hypoxemic ARF. With regard to weaning from invasive mechanical ventilation, immediate application of NPPV after extubation showed a lower mortality rate compared to continued invasive weaning. Moreover, NPPV with active humidification significantly decreased the reintubation rate within 7 days after extubation compared with HFNC. The choice between using NPPV and HFNC should be based on the specific etiology of the patient's condition. The potential effect of noninvasive high-frequency oscillatory ventilation on CO2 clearance was also investigated.

[Annual review of progress in research on chronic obstructive pulmonary disease(2022-2023)]

Chronic obstructive pulmonary disease (COPD) is the most common chronic airway disease, with a high prevalence and high disease burden. Clinical questions have driven advances in clinical research that continue to deepen our understanding of COPD. At the same time, new perspectives, evidence, and strategies have emerged. Studies since 2022 have increased knowledge of the impact of risk factors, such as low-to-moderate income and ambient ozone, on the prevalence of COPD. The effect of preterm birth on obstructive lung function deficits and COPD in the sixth decade of life was investigated for the first time. Screening studies for COPD in developed and low- and middle-income countries suggest the importance of tailoring screening strategies to local conditions. Developments in artificial intelligence provide a general framework for using machine-learning-based methods and medical record-based labels to improve disease prediction. New perspectives on endotypes/phenotypes and prognostic assessment of COPD were provided by lifetime spirometry patterns of obstruction and limitation, sensitisation to recombinant Aspergillus fumigatus allergens, airway-occluding mucus plugs and exacerbation history in COPD group A and B patients. Clinical trials focusing on inflammatory mediators, comorbidity treatment, non-pharmacological treatments, and environmental interventions shed light on some crucial and long-debated issues. Further research is needed for individualised diagnosis and treatment of COPD.

Towards Clinical Proton Minibeam Radiation Therapy (pMBRT): Development of Clinical pMBRT System Prototype and pMBRT-Specific Treatment Planning Method

PURPOSE/OBJECTIVE(S)

Proton minibeam radiation therapy (pMBRT) is an emerging spatially fractionated RT (SFRT) modality that can provide very high therapeutic index compared to conventional radiotherapy methods and clinically-available SFRT methods (GRID and LATTICE). The biological data collected thus far encourage the preparation of clinical trials in pMBRT. This work is to facilitate the clinical translation of pMBRT by developing (1) the first clinical pMBRT system prototype worldwide, readily available for both small-animal biology studies and large-animal pMBRT trials; (2) pMBRT-specific treatment planning method with peak-valley dose ratio (PVDR) optimization capability for large animal and patient pMBRT trials, which is currently unavailable.

MATERIALS/METHODS

The pMBRT system is based on clinically-used pencil-beam-scanning proton machine equipped with large-field clinical-size pMBRT collimator, pMBRT-dedicated treatment planning system, and KV/CBCT imaging guidance. The multi-slit brass collimator has 10 × 10 cm field size, 0.4mm width per slit and 4 mm center-to-center distance. The divergence of slits is tailed to the divergence of the proton beam. A unique universal collimator design is implemented, so that we can keep the outer fitting to the snout and conveniently inter-change collimators as needed. The pMBRT-specific treatment planning method jointly optimizes PVDR and dose objectives, to meet a minimal PVDR threshold and maximize PVDR, to avoid the situations where meeting dose objectives can compromise PVDR when PVDR were not optimized. In addition, the survival fraction for organs at risk is also optimized. The dose calculation engine is based on the Monte Carlo method using TOPAS. The optimization algorithm utilizes total variation and L1 sparsity regularization to maximize PVDR and iterative convex relaxation method to solve the optimization problem.

RESULTS

Monte Carlo simulations via TOPAS were performed to design this large-field multi-slit collimator, using the beam structure and the beam data specific to our proton system, with mean dose rate of 8 Gy/min under clinical condition with the collimator in place. The feasibility of using this pMBRT system for small-animal studies has been demonstrated, with customized 3D printed holder for immobilizing small animals, on-board KV imaging system for accurate small-animal positioning, and the GAFchromic film for verifying radiation dose and PVDR. On the other hand, the efficacy of pMBRT-specific treatment planning method (with PVDR optimization capability) to improve PVDR has been demonstrated using retrospective patient planning studies in comparison with standard proton treatment planning method (without PVDR optimization capability).

CONCLUSION

The initial development of a clinical pMBRT system prototype and pMBRT-specific treatment planning method of PVDR optimization capability has been completed with ongoing efforts to make this system ready for large-animal pMBRT studies.

Risk Factors Predicting Relapse 10 Years Following Extreme Dose-Escalated SBRT for Intermediate-Risk Prostate Cancer: Is De-Intensification Feasible in Unfavorable Subgroups?

PURPOSE/OBJECTIVE(S)

Adding short-term androgen-deprivation therapy (ADT) to radiotherapy is recommended in unfavorable intermediate-risk (UIR) prostate cancer (PCa). Data supporting the addition of ADT to stereotactic body radiotherapy (SBRT) in intermediate-risk (IR) patients are limited. Given ADT has well-documented toxicities, we sought to identify the UIR prognostic factors that predict for relapse following SBRT without ADT. We combined results from two mature multicenter trials to determine if extreme dose-escalated SBRT yielded UIR subgroups in which the omission of ADT may be considered.

MATERIALS/METHODS

Between 2008 and 2011, two prospective national trials enlisted 39 centers to enroll 285 patients with IR PCa: 182 had Memorial Sloan Kettering (MSK) favorable intermediate-risk (FIR) and 103 had MSK UIF PCa. All were treated with a non-coplanar robotic SBRT platform using real-time tracking of implanted fiducials. Two dose regimens were used: 40Gy in 5 fractions of 8Gy, and 38Gy in 4 fractions of 9.5Gy. ADT was not allowed. Univariate and multivariate analyses using a Cox proportional hazards model was performed for relapse free survival (RFS): relapse included pathologic or radiographic failure, initiation of salvage or systemic therapy, or biochemical relapse by the nadir + 2 definition. Insufficient events prevented similar analyses for local control, metastasis-free and PCa-specific survival. Examined risk factors included dose regimen, clinical T-stage, Gleason score, pre-treatment PSA, % positive biopsy cores, and number of unfavorable risk factors (URFs). All reported rates are actuarial, using Kaplan-Meier method.

RESULTS

Median follow-up was 8.1 years. 71 patients were followed 10 years. There were no statistically significant differences in rates of toxicity, local failure, RFS, overall nor metastasis-free survival between the two dose regimens. For the entire group, 10-year overall survival was 82.9%, RFS was 83.2%, and the local failure rate was 3.6%. On univariate analysis, primary Gleason pattern 4 (PGP4) and >2 URFs predicted for RFS. On multivariate analysis, only PGP4 (hazard ratio: 3.71, p = 0.0053) was statistically significant. Examining the UIR subgroup, the only predictor for RFS was PGP4 (HR: 3.64, p = 0.0253). 10-year RFS was 88.4% for FIR and 89.1% for UIR without PGP4; this fell to 58.5% in patients with a PGP4.

CONCLUSION

Following dose-escalated SBRT monotherapy, 10-year RFS rates were favorable in UIR patients without PGP4. Extreme dose escalation appeared to effectively address UIR factors correlating with tumor bulk (i.e., CS T2b, >50% cores+, PSA 10-20), but was less effective with biologically aggressive pathology (PGP4). A randomized trial, ideally including genomic classification, would be necessary to determine if dose-escalated SBRT allows de-intensification (omission of ADT) in such biologically less aggressive UIR subgroups. The high relapse rate observed in UIR patients with PGP4 affirms the need for adjuvant ADT in this subgroup.

Virtual-Collimator Based Spatial Dose Modulation for Proton GRID Therapy

PURPOSE/OBJECTIVE(S)

Compared to conventional proton therapy, the proton GRID therapy can substantially improve normal tissue protection (with the delivery of spatially-modulated peak-valley dose pattern to normal tissues) while maintaining the tumor control efficacy (with the delivery of uniform dose pattern to tumor targets). The realization of proton GRID often relies on the use of physical collimators to shape the spatial dose distribution. However, the physical collimator may increase neutron dose, decrease delivery efficiency, and limit the freedom for patient positioning. Here we propose a virtual-collimator (VC) method for proton GRID. This new approach can generate peak-to-valley pattern with high peak-to-valley dose ratio (PVDR), without using a physical collimator.

MATERIALS/METHODS

The principle behind the VC method to modulate the spatial dose distribution consists of two major steps: (1) the primary beam is essentially halved, i.e., the beamlets are interleaved, so that the organ-at-risk (OAR) plane has the peak-valley dose pattern, while the target plane also has the valley dose; (2) the complementary beam is added with half complementary beamlets to fill in the previously valley-dose positions at the target plane, so that the target dose is uniform, while on the other hand, the complementary beam is angled slightly from the primary beam, so that the OAR still has the peak-valley dose pattern. Moreover, on top of VC, we also utilize sparsity regularization method using total variation and L1 sparsity (TVL1) to further jointly optimize PVDR and dose objectives, namely VC-TVL1.

RESULTS

VC and VC-TVL1 were validated in comparison with conventional proton GRID treatment planning method via IMPT ("CONV") and TVL1-based proton GRID treatment planning method without VC ("TVL1"), for a prostate case with single-beam (270° only) or two-beam (90° and 270°) scenarios. As shown in the table, the results show that VC can indeed modulate spatial dose with higher PVDR than CONV or even TVL1. VC had higher spatial modulation frequency with smaller peak-to-peak distance than TVL1. Moreover, VC+TVL1, as the synergy of VC and TVL1, further improved PVDR from VC or TVL1 alone.

CONCLUSION

A new way to deliver proton GRID therapy without a physical collimator is developed using the VC method. The VC method can be synergized with TVL1 optimization algorithm to further jointly optimize PVDR and dose objectives.

2V-CBCT: Two-Orthogonal-Projection Based CBCT Reconstruction and Dose Calculation from Real CBCT Projection Data

PURPOSE/OBJECTIVE(S)

Not all radiation therapy (RT) treatments/fractions have CBCT acquired, but two orthogonal projections (i.e., KV radiography) are always available. This work demonstrates the feasibility of two-orthogonal-projection-based CBCT (2V-CBCT) reconstruction and dose calculation for RT from real CBCT projection data, which is the first 2V-CBCT feasibility study using real projection data, to the best of our knowledge.

MATERIALS/METHODS

2V-CBCT is a severely ill-posed inverse problem for which we propose a coarse-to-fine learning strategy. First, a 3D deep neural network that can extract and exploit the inter-slice and intra-slice information is adopted to predict the initial 3D volumes. Then, a 2D deep neural network is utilized to fine-tune the initial 3D volumes slice-by-slice. During the fine-tuning stage, a perceptual loss based on multi-frequency features is employed to enhance the image reconstruction. Dose calculation results from both photon and proton RT demonstrate that 2V-CBCT provides comparable accuracy with full-view CBCT based on real projection data.

RESULTS

The proposed method was evaluated on real HN data acquired from on-board CBCT scanners rather than the low-resolution simulated data or down-sampled data. Both visual assessment and quantitative analysis demonstrate that the proposed coarse-to-fine learning strategy has the potential to produce satisfactory volumetric images from two orthogonal projections. Furthermore, we assessed the utility of 2V-CBCT in RT. The results show that the dose distribution maps, dose-volume histograms, and dose parameters calculated using 2V-CBCT have comparable accuracy with the counterparts calculated using the corresponding full-view CBCT for both photon and proton RT. In the table, the methods under comparison are pCT (planning CT), FV-CBCT (CBCT reconstructed with full-view projection data), and 2V-CBCT (CBCT reconstructed with two orthogonal projections).

CONCLUSION

A new effective 2V-CBCT reconstruction method is proposed and validated using real CBCT projection data, which can potentially provide comparable dose calculation accuracy for both photon and proton RT.

A New Treatment Planning Method for Efficient Proton ARC Therapy with Direct Minimization of Number of Energy Jumps

PURPOSE/OBJECTIVE(S)

The optimization of energy layer distributions is crucial for efficient proton ARC therapy: on one hand, a sufficient number of energy layers is needed to ensure the plan quality; on the other hand, an excess number of energy jumps can substantially slow down the treatment delivery. This work will develop a new treatment plan optimization method with direct minimization of number of energy jumps (NEJ), which will be shown to outperform state-of-the-art methods in both plan quality and delivery efficiency.

MATERIALS/METHODS

The proposed method jointly optimizes the plan quality and minimizes the NEJ. To minimize NEJ, (1) the proton spots x is summed per energy layer to form the energy vector y; (2) y is binarized via sigmoid transform into y1; (3) y1 is multiplied with a predefined energy order vector via dot product into y2; (4) y2 is filtered through the finite-differencing kernel into y3 in order to identify NEJ; (5) only the NEJ of y3 is penalized, while x is optimized for plan quality. The solution algorithm to this new method is based on iterative convex relaxation.

RESULTS

The new method is validated in comparison with state-of-the-art methods called energy sequencing (ES) method and energy matrix (EM) method. In terms of delivery efficiency, the new method had fewer NEJ, less energy switching time, and generally less total delivery time. In terms of plan quality, the new method had smaller optimization objective values, lower normal tissue dose, and generally better target coverage. A head-and-neck case is provided in the table with the following dosimetric parameters: planning objective value F; conformity index CI; homogeneity index HI; mean dose of larynx DOAR; mean body dose Dbody; the unit of dose is Gy.

CONCLUSION

We have developed a new treatment plan optimization method with direct minimization of NEJ, and demonstrated that this new method outperformed state-of-the-art methods (ES and EM) in both plan quality and delivery efficiency.

Vertex Position Optimization for LATTICE Therapy

PURPOSE/OBJECTIVE(S)

LATTICE radiation therapy (RT) aims to deliver 3D heterogenous dose of high peak-to-valley dose ratio (PVDR) to the tumor target, with peak dose at lattice vertices inside the target and valley dose for the rest of the target. In current clinical practice the lattice vertex positions are constant during treatment planning. This work proposes a new LATTICE plan optimization method that can optimize lattice vertex positions as plan variables, which is the first lattice vertex position optimization study to the best of our knowledge.

MATERIALS/METHODS

The new LATTICE treatment planning method optimizes lattice vertex positions as well as other plan variables (e.g., photon fluences or proton spot weights), with optimization objectives for target PVDR and organs-at-risk (OAR) sparing. To satisfy mathematical differentiability, the lattice vertices are approximated in sigmoid functions. For geometric feasibility, proper geometry constraints are enforced onto the lattice vertex positions. The lattice vertex position optimization problem is solved by iterative convex relaxation method, where lattice vertex positions and photon/proton plan variables are jointly updated via the Quasi-Newton method.

RESULTS

Both photon and proton LATTICE RT were considered, and the optimal lattice vertex positions in terms of plan objectives were found by solving all possible combinations on given discrete positions via heuristic searching based on standard IMRT/IMPT, which served as the ground truth for validating the new LATTICE method ("NEW"). That is, the plan with the smallest optimization objective ("BEST"), the plan with the median optimization objective ("MID"), and the plan with the largest optimization objective ("WORST") were selected as the reference plans to be compared with NEW. The table was for an abdomen case with the large bowel as the OAR, where the parameters are total optimization objective f, the mean valley dose of target Dvalley, the mean peak dose of target Dpeak, PVDR = Dpeak/Dvalley, and the mean dose of large bowel Dbowel. The unit of doses is Gy. The results in the table show that the new method indeed provided the optimal lattice vertex positions with the smallest optimization objective, the largest target PVDR, and the best OAR sparing.

CONCLUSION

A new LATTICE treatment planning method is proposed and validated that can optimize lattice vertex positions as well as other photon or proton plan variables for improving target PVDR and OAR sparing.

[Investigation on cognition, diagnosis and treatment status of chest tightness variant asthma among Chinese pediatricians]

Objective: To evaluate the awareness, diagnosis and treatment of chest tightness variant asthma (CTVA) among pediatricians in China. Methods: The survey was conducted by convenient sampling method. Pediatricians with professional title of attending physician and above from different grades hospitals in 30 provinces were invited to conduct online questionnaire surveys through WeChat, pediatricians scan QR codes to complete electronic questionnaires in the mini program from January 16th to February 4th, 2021. The contents of questionnaire included the awareness, diagnosis and treatment of CTVA, and comparing the differences between pediatricians in secondary hospitals and tertiary hospitals. Results: A total of 1 529 pediatricians participated in the survey, and 1 484 (97.06%) pediatricians completed the questionnaire and included in the analysis, including 420 males (28.30%). The awareness rate of CTVA among pediatricians was 77.83 % (1 155/1 484). Pediatricians in tertiary hospitals had higher rates of awareness of CTVA than pediatricians in secondary hospitals [81.86% (898/1 097) vs 66.41% (257/387), P<0.001] and had better execution of the guidelines [89.15% (978/1 097) vs 79.59% (308/387), P<0.001]. A total of 93.06 % (1 381/1 484) of pediatricians' first-line treatment included inhaled corticosteroids (ICS) for CTVA. Among them, a higher proportion of pediatricians in tertiary hospitals used ICS included regimens for first-line treatment of CTVA compared with pediatricians in secondary hospitals [94.90% (1 041/1 097) vs 87.86% (340/387), P<0.001]. The reported well control rate of CTVA was 32.08% (476/1 484), which was significantly lower in secondary hospitals than that in tertiary hospitals [17.31% (67/387) vs 37.28% (409/1 097), P<0.001]. Conclusion: Most pediatricians are well aware of CTVA, among which there is a certain gap in clinical practice between pediatricians in secondary hospitals and tertiary hospitals in terms of understanding, diagnosis, and treatment of CTVA.

[MiR-340 mediates the involvement of high mobility group box 1 in the pathogenesis of liver fibrosis]

Objective: To explore the pathogenic mechanism of the miR-340/high mobility group box 1 (HMGB1) axis in the formation of liver fibrosis. Methods: A rat liver fibrosis model was established by injecting CCl(4) intraperitoneally. miRNAs targeting and validating HMGB1 were selected with gene microarrays after screening the differentially expressed miRNAs in rats with normal and hepatic fibrosis. The effect of miRNA expressional changes on HMGB1 levels was detected by qPCR. Dual luciferase gene reporter assays (LUC) was used to verify the targeting relationship between miR-340 and HMGB1. The proliferative activity of the hepatic stellate cell line HSC-T6 was detected by thiazolyl blue tetrazolium bromide (MTT) assay after co-transfection of miRNA mimics and HMGB1 overexpression vector, and the expression of extracellular matrix (ECM) proteins type I collagen and α-smooth muscle actin (SMA) was detected by western blot. Statistical analysis was performed by analysis of variance and the LSD-t test. Results: Hematoxylin-eosin and Masson staining results showed that the rat model of liver fibrosis was successfully established. Gene microarray analysis and bioinformatics prediction had detected eight miRNAs possibly targeting HMGB1, and animal model validation had detected miR-340. qPCR detection results showed that miR-340 had inhibited the expression of HMGB1, and a luciferase complementation assay suggested that miR-340 had targeted HMGB1. Functional experiments results showed that HMGB1 overexpression had enhanced cell proliferation activity and the expression of type I collagen and α-SMA, while miR-340 mimics had not only inhibited cell proliferation activity and the expression of HMGB1, type I collagen, and α-SMA, but also partially reversed the promoting effect of HMGB1 on cell proliferation and ECM synthesis. Conclusion: miR-340 targets HMGB1 to inhibit the proliferation and ECM deposition in hepatic stellate cells and plays a protective role during the process of liver fibrosis.

[Clinical update in non-invasive positive pressure ventilation for respiratory failure in 2022]

In this article, we searched the research literatures related to clinical investigation of non-invasive positive pressure ventilation (NPPV) in acute respiratory failure(ARF)/chronic respiratory failure(CRF) between 1^st October 2021 and 30^th September 2022 through Medline, and reviewed the important advances. Three prospective randomized controlled studies related to the efficacy and safety of NPPV and/or high-flow nasal cannula oxygen therapy (HFNC) on patients with COVID-19 with ARF were reported, showing that NPPV (including continuous positive airway pressure and bilevel positive airway pressure) was able to reduce the intubation rate, but the efficacy of HFNC was contradictory. In addition, progress has been made in outcome prediction models for ARF treated with NPPV, NPPV-related cardiac arrest, and the impact of human-machine interface on NPPV treatment outcomes. The effects of NPPV as preoxygenation method before intubation was reported to be able to reduce severe desaturation during intubation, especially in obese population. The use of NPPV in extubated patients resulting in reduced reintubation rate was also studied. With regard to long-term home application of NPPV, five indicators of successful initiation were proposed, but the success rate was low in clinical practice. Some reports showed that psychological support could improve the adherence to NPPV. The results of these studies contributed to the rational selection and optimal application of NPPV in clinical practice.

[Effect of closed extension tube on preventing airway leakage during artificial airway clearance]

Objective: To explore the role of closed extension tube in preventing airway leakage during artificial airway clearance. Methods: The test lung was connected with a ventilator for mechanical ventilation. The pressure parameters were set as 16/5, 20/6, 24/7, 28/8, 32/9 and 36/10 cmH₂O(1 cmH₂O=0.098 kPa), respectively. The circuit was connected with an open extension tube or a closed extension tube. The ventilator was set with different pressure parameters to observe the changes of airway pressure and tidal volume during airway clearance. Results: (1) The pressure parameters were set as 16/5, 20/6, 24/7, 28/8, 32/9 and 36/10 cmH₂O, and the airway pressures (in cmH₂O) of circuit connected with open extension tube were (15.94±0.27)/(4.81±0.04), (20.09±0.23)/(6.05±0.16), (23.89±0.41)/(6.94±0.06), (27.90±0.22)/(7.71±0.18), (31.92±0.13)/(8.74±0.12)and(35.65±0.31)/(9.72±0.07), respectively.Under the same ventilator pressure parameters, the airway pressures (in cmH₂O) of circuit connected with close extension tube were (16.36±0.06)/(4.85±0.04), (20.54±0.26)/(6.44±0.12), (24.36±0.24)/(7.01±0.33), (28.69±0.25)/(8.07±0.08), (32.97±0.33)/(8.93±0.09), (37.34±0.29)/(9.75±0.08), respectively. The airway pressure of circuit connected with open extension tube was lower than that connected with closed extension tube(P<0.05);with the increase of the pressure setting of the ventilator, the difference of the airway pressure between the two extended tubes gradually increased. When the maximum inspiratory pressure of the ventilator was set 36 cmH₂O, the difference reached 1.69 cmH₂O. (2) The airway pressures (in cmH₂O) dropped from (15.94±0.27)/(4.81±0.04), (20.09±0.23)/(6.05±0.16), (23.89±0.41)/(6.94±0.06), (27.90±0.22)/(7.71±0.18), (31.92±0.13)/(8.74±0.12), (35.65±0.31)/(9.72±0.07) to (13.42±0.4)/(3.15±0.14), (16.81±0.6)/(4.30±0.14), (20.22±0.5)/(5.48±0.45), (23.73±1.4)/(6.25±0.22), (24.78±0.7)/(7.13±0.21), (20.83±0.4)/(6.61±0.19)when the suction port of the open extension tube was opened (P<0.05);and the tidal volume (in L) also decreased from 0.328±0.004, 0.580±0.012, 0.621±0.003, 0.626±0.003, 0.615±0.003, 0.603±0.002 to 0.272±0.008, 0.416±0.051, 0.487±0.047, 0.396±0.116, 0.507±0.022, 0.508±0.079, respectively (P<0.05). The decrease of airway pressure and tidal volume gradually increased with the increase of ventilator setting pressure. When the ventilator setting parameter was 36/10 cmH₂O, the decrease of airway inspiratory pressure was (14.82±0.51) cmH₂O and the maximum reduction of tidal volume was (0.164±0.021)L. (3)The airway pressure (in cmH₂O) was increased to(15.70±0.23)/(4.80±0.33), (19.01±0.81)/(5.71±0.34), (22.27±0.62)/(6.85±0.44), (25.35±2.09)/(7.94±0.16), (28.38±0.46)/(8.96±0.23), (33.34±0.71)/(9.71±0.25) when the suction tube was inserted from the suction port of the open extension tube in the open state, and the tidal volume (in L) was increased to 0.340±0.016, 0.563±0.020, 0.571±0.030, 0.556±0.026, 0.514±0.021, 0.512±0.031 as well.The airway pressure and tidal volume of the ventilation circuit were higher than those in the open state, but still lower than those in the closed state. Compared with the closed state of the suction port, the maximum pressure drop and tidal volume decrease were (3.53±0.46) cmH₂O and (0.101±0.011) L, respectively. (4) The pressure of the ventilator was set between 16/5 cmH₂O to 36/10 cmH₂O. The airway pressure (in cmH₂O) was decreased from (16.26±0.04)/(4.85±0.04), (20.74±0.15)/(6.42±0.11), (25.09±0.31)/(7.10±0.13), (29.38±0.24)/(8.17±0.09), (33.80±0.16)/(9.02±0.17), (37.89±0.19)/(9.83±0.07) to(16.36±0.06)/(4.85±0.04), (20.54±0.26)/(6.44±0.12), (24.36±0.24)/(7.01±0.33), (28.69±0.25)/(8.07±0.08), (32.97±0.33)/(8.93±0.09), (37.34±0.29)/(9.75±0.08), respectively during the insertion of the suction tube from the suction port of the closed extension tube, and the tidal volume (in L) was decreased from0.361±0.005, 0.592±0.003, 0.631±0.001, 0.642±0.007, 0.633±0.007, 0.626±0.08 to 0.335±0.005, 0.588±0.008, 0.631±0.002, 0.638±0.004, 0.628±0.004, 0.618±0.005.The maximum pressure change of the ventilation circuit was (0.83±0.27) cm H₂O and the maximum tidal volume change was (0.008±0.006)L. The changes of airway pressure and tidal volume were significantly lower than those of ventilation circuit connected with open extension tube under the same pressure parameters. Conclusion: The connection of closed extension tube in mechanical ventilation circuit can reduce the airway leakage during artificial airway clearance, which is worthy of clinical recommendation.

[Hyper-IgE syndrome in adults characterized by disseminated mixed infection: a case report and literature review]

Objective: To improve the awareness of hyper-IgE syndrome (HIES) characterized by disseminated infection. Methods: We retrospectively analyzed a patient with HIES characterized by Talaromyces marneffei and Staphylococcus aureus mixed disseminated infection in Shenzhen People's Hospital. The clinical manifestations, results of laboratory tests/genetic examinations, therapeutic strategies and prognosis were summarized. The keywords "hyper-lgE syndrome" were used to search and review the literature in Wanfang databases and Pubmed database. Results: In February 2021, an 18-year-old male patient was admitted to our hospital with backache for over 3 weeks and fever for 4 days. Physical examination revealed deciduous teeth in the oral cavity, bilateral renal pain on percussion, and interphalangeal joint hyperextension. Laboratory studies demonstrated increased blood eosinophils and serum level of total IgE. Bacterial culture from bronchoscopic secretions, bronchial mucosa, and necrotic tissue from the left upper arm showed Talaromyces marneffei. Bacterial culture from alveolar lavage fluid, left upper arm necrotic tissue, puncture fluid of right retroauricular abscess and renal drainage fluid suggested methicillin-sensitive Staphylococcus aureus. The chest and abdominal CT revealed diffuse patchy and nodular lesions in bilateral lungs, cavitary lesions in the upper lobe of the left lung, multiple enlarged lymph nodes in the mediastinum, and infectious lesions within both kidneys and perirenal space. Furthermore, the patients was identified with STAT3 mutations by whole exome sequencing, which confirmed the diagnosis of HIES. Nineteen literature articles were retrieved, involving 27 adult patients with a median age of diagnosis of 23 years. The most common manifestations included: skin infection (16/27), eczema (15/27), elevated IgE (26/27) and eosinophils (17/27), as well as positive STAT3 mutation (11/27). Conclusion: Clinicians should be alert to the possibility of hyper-IgE syndrome in patients with severe or disseminated intracellular bacterial infections.

[Two families with Birt-Hogg-Dubé syndrome:case report and literature review]

Objective: To improve the awareness of Birt-Hogg-Dubé syndrome. Methods: We performed a retrospective analysis with two families of Birt-Hogg-Dubé syndrome (BHD syndrome) diagnosed in Department of Respiratory and Critical Care Medicine, Shenzhen People's Hospital from 2020 to 2021. Clinical manifestations, imaging features, diagnosis and gene detection results were summarized. Relative literatures were reviewed in Wanfang Database and PubMed from 2015 to 2021 by using the search terms of "BHD syndrome" "Birt-Hogg-Dubé" "Birt-Hogg-Dubé syndrome", respectively. Results: The probands of both families were female, aged 37 and 34 years respectively. The onset manifestation was pulmonary bullae combined with pneumothorax. Chest computed tomography (CT) imaging showed multiple pulmonary cysts in both lobes, and no skin lesions or renal tumors were found in either case. History of pneumothorax was present in Family 1 while absent in Family 2. The FLCN gene of the two probands and their relatives showed the same mutation site. Totally 12 Chinese literatures and 394 English literatures were retrieved, among which 96 reported lung involvement only. A total of 10 literatures about Chinese population were screened out from the English literatures, and 115 patients, 31 males and 84 females, were included. The incidence of spontaneous pneumothorax was 66.95% (77/115), while a family history of pneumothorax was 88.31%(68/77). The onset age of spontaneous pneumothorax was between 30 and 44 years. The most common mutation site of FLCN was c.1285dup. Conclusions: BHD syndrome in Asian population may only have lung involvement. Patients with pneumothorax and pulmonary cystic lesions should be inquired of the family history. We speculate that there are many underdiagnosed cases in clinical practice.

[Clinical research progress in non-invasive positive pressure ventilation from 2020 to 2021]

Non-invasive positive pressure ventilation (NPPV), an essential respiratory support method, is widely used in acute/chronic respiratory failure and assisting rehabilitation in patients with chronic obstructive pulmonary disease (COPD). We searched the relevant research articles about NPPV published from 1^st October 2020 to 30^th September 2021 through Medline. Researches focusing on the clinical application and viral transmission protection during high-flow nasal cannula oxygen and NPPV in COVID-19, were mainly retrospective and of small sample size. It demonstrated that high-flow nasal cannula oxygen and NPPV might reduce intubation rates when treating patients with mild-to-moderate respiratory failure, but the risk of delayed intubation should draw particular precaution. When using NPPV in non-COVID-19-related de novo acute respiratory failure, diaphragm thickening fraction and tidal change of esophageal pressure were validated to predict the treatment outcome. In addition, some studies explored the compliance and related influencing factors associated with the treatment effects of early NPPV initiation on amyotrophic lateral sclerosis patients and the effects of NPPV on dynamic hyperinflation during exercise in COPD patients. Furthermore, the effectiveness of neurally adjusted ventilatory assist ventilation and a novel communication device optimizing the use of NPPV were also investigated and outlined.

[Correlation between aspiration and long-term survival of inpatients with chronic obstructive pulmonary disease]

Objective: To retrospectively analyze the high risk factors of death in patients with chronic obstructive pulmonary disease (COPD) and to explore the influence of aspiration on the long-term survival rate of COPD patients. Methods: A retrospective analysis of clinical data of inpatients, who were admitted to the First Affiliated Hospital of Guangzhou Medical University from April 2012 to December 2013 due to COPD exacerbations and had radionuclide aspiration test, was conducted. Meanwhile, we phoned the patients' family members, whose phone numbers were recorded in the electronic patient record system, to follow up the patients' survival status, and learn the causes of death from their death records if patients died during follow-up period. Inquired the resident administration patients belonging to according to their original address to get patient's current contact information if changed. Besides, if family members of patients failed to provide death record, we should look up information concerned from the medical records room of the hospital where they died. Results: The follow-up for the last patient was performed on February 20, 2017.The time span of this study is 58 months, starting from the radionuclide aspiration test for the first patient and ending with the follow-up for the last patient. 16 of the 53 patients(16/53, 30.2%)were tested positive whose average age was slightly higher than patients without aspiration (76.0±6.8 vs 70.9±9.9), but there was no significant difference between them(P=0.064). The aspiration rates among patients over and under the age of seventy were 14/35 and 2/18 respectively, and there was a significant difference between them(P = 0.03). Compared to the aspiration-negative patients, the aspiration-positive patients had higher incidence rate of pneumonia in COPD exacerbations (11/16 vs 9/37, χ²= 9.383, P = 0.002).The major cause of death in the patients with and without aspiration were respectively severe pneumonia and pulmonary encephalopathy(P<0.05 in both cases).Among COPD patients who took radionuclide aspiration test, the median survival time of the patients with and without aspiration were about 3 and 5 years respectively. The high-risk factors influencing long-term survival of the COPD patients with aspiration included ICU-involved medical history and accompanying pneumonia. Conclusions: The incidence rate of aspiration is relatively high in COPD patients over 70 years old. Compared to COPD patients without aspiration, COPD patients with aspiration have higher incidence rate of pneumonia and shorter median survival time. ICU-involved medical history and severe pneumonia are the two high-risk factors influencing long-term survival of COPD patients with aspiration.To improve the survival time of COPD patients with aspiration, we need to attach importance to the prevention and treatment of aspiration.

[A prospective multi-center clinical investigation of HIV-negative pulmonary cryptococcosis in China]

Objective: To investigate the current status of the diagnosis and treatment of pulmonary cryptococcosis in respiratory medicine and improve the understanding of the clinical characteristics of HIV-negative pulmonary cryptococcosis in China. Methods: A prospective multi-center open cohort study was designed to screen for pulmonary cryptococcosis in the general wards and intensive care units of the Department of Respiratory Diseases in 22 hospitals. The HIV-negative patients with positive cryptococcal etiological diagnosis based on smear culture, antigen detection and histopathology were enrolled in the study. The clinical data of enrolled patients were collected and analyzed. Results: A total of 457 cases of pulmonary cryptococcosis were enrolled, among which 3.28% (15/457) were disseminated infections. The case fatality rate was 0.88% (4/457). The majority of the cases were diagnosed by histopathological examinations (74.40%, 340/457) and cryptococcus antigen detection (37.64%, 172/457). Patients with pulmonary cryptococcosis accounted for 2.04‰ (457/223 748) of the total hospitalized patients in the Department of Respiratory Diseases during the same period, and the ratio was the highest in south and east China. Meanwhile, 70.24% (321/457) of the patients had no underlying diseases, while 87.75% (401/457) were found to have immunocompetent status. Cough and expectoration were the most common clinical symptoms in patients with pulmonary cryptococcosis. However, 25.16% (115/457) of the patients had no clinical symptom or physical signs. In terms of imaging features on pulmonary CT, multiple pulmonary lesions were more common than isolated lesions, and there were more subpleural lesions than perihilar or medial lesions. Morphologically, most of the lesions were middle-sized nodules (1-5 cm) or small-sized nodules (3 mm to 1 cm). The sensitivity of serum cryptococcus antigen test was 71.99% (203/282). Moreover, antigen-positive patients differed from antigen-negative patients in terms of basic immune status, clinical symptoms, imaging features and infection types. Meanwhile, immunocompromised patients differed from immunocompetent patients in terms of clinical symptoms, physical signs, infection-related inflammation indicator levels, imaging features, serum cryptococcus antigen positive rate and prognosis. Conclusions: The majority of cases of HIV-negative pulmonary cryptococcosis in China had no underlying disease or immunocompromised status, and the overrall prognosis was favorable. However, early diagnosis of HIV-negative pulmonary cryptococcosis remains challenging due to the complicated manifestations of the disease.

How to safely and sustainably reorganise a large general radiography service facing the COVID-19 pandemic

Objectives

This paper aims to share our experience in reorganising our general radiography service during the coronavirus disease (COVID-19) pandemic from the viewpoint of a large tertiary referral medical centre.

Key findings

Re-organization of the radiography workforce, patient segregation, and modification of routine radiographic practices are key measures to help radiographic services deal with the COVID-19 pandemic. Specific emphasis on deploying more mobile radiographic units, segregating equipment, developing consistent image acquisition workflows, and strict adherence to infection control protocols are paramount to minimize the possibility of in-hospital transmission and ensure a safe environment for both patients and staff. Streamlining communication channels between leadership and ground staff allows quick dissemination of information to ultimately facilitate safe provision of services.

Conclusion

COVID-19 has drastically altered the way general radiography teams provide services. The institution of several key measures will allow hospitals to safely and sustainably provide radiographic services. To date, there have been zero incidences of radiographer healthcare worker transmission within our institution during the course of work.

Implication for practice

Radiographers are facing the challenge of providing high-quality services while simultaneously minimizing pathogen exposure to staff and patients. Our experience may lend support to other radiographic services responding to the COVID-19 outbreak and serve as a blueprint for future infectious disease outbreak contingency plans.

[The application of extended high frequency audiometry in detecting the early hearing loss for polycystic ovarian syndrome]

Objective:To preliminarily explore the clinical significance of extended high frequency audiometry in evaluating the early hearing loss in patients with polycystic ovarian syndrome（PCOS）. The results were statistically analyzed. Method:The hearing threshold of forty young women diagnosed as PCOS and 20 healthy controls were obtained by using conventional audiometry（0.25-8.00 kHz） and extended high frequency（10-20 kHz） pure tone audiometry. Result:The hearing thresholds of the two groups were similar at conventional frequencies of 0.25，0.50，1.00，2.00 and 4.00 kHz（P>0.05）. The hearing threshold of PCOS group at 8-20 kHz frequency was significantly higher than that of the control group, and the difference was statistically significant（P<0.05）. The expanded high-frequency detectable rate was lower in PCOS group than that in control group, especially at 16 and 18 kHz （P<0.05） and the differences were statistically significant. Conclusion:The early hearing impairment of PCOS patients starts from the extended high frequency, which is more sensitive than the conventional pure tone audiometry in the early hearing impairment assessment of PCOS patients.

Subdural haematoma mimics

A subdural haematoma (SDH) is a frequently encountered pathology seen on an emergency room computed tomography (CT) head scan. An extra-axial crescentic density along the convexity of the brain or within the interhemispheric fissure is generally thought to represent a SDH; however, SDH mimics are known to occur in nature, and can be broadly classified under the subcategories of normal anatomy, artefacts, tumour, inflammation, infection, ischaemia, trauma, and iatrogenic. Understanding the typical characteristics of a SDH, knowledge of normal anatomy, close inspection of the morphology of the subdural process, changes to the adjacent structures, and rigorous attention to clinical details may reveal subtle clues that distinguish a true SDH from a mimic. This is crucial in appropriately directing clinical management. This review amalgamates most of the rare subdural processes that have been reported to mimic SDH, and discusses the imaging and clinical features that help to differentiate between them. This topic is highly valuable for radiology trainees, general radiologists, and emergency room physicians, and may serve as a refresher for the practising neuroradiologist.

[Clinical analysis of 3 cases of eosinophilic granulomatosis with polyangiitis]

Objective: To improve the clinical recognition of eosinophilic granulomatosis with polyangiitis(EGPA) in clinical manifestations, diagnosis and treatment. Methods: The clinical manifestations, pathological characteristic, imaging manifestations, diagnosis and the therapy of three patients with EGPA were presented. Results: These 3 patients had asthma-like symptoms and extrapulmonary manifestations of systemic vasculitis. They were 20, 40 and 44 years old. All of them were female.They denied exposure or contact. Chest radiographic examination showed that the most common features were nodule shadow and tree-in-bud in the lung. The pathological manifestation was characterized by hypereosinophilia, high total IgE(over 300 KU/L) and high CRP(over 14.1mg/L). The FeNO of 2 patients was over 100ppb. The ANCA of these 3 patients was negative. The pulmonary pathology was observed had eosinophil infiltration in the alveolar, interstitial and vessel for 3 cases. The clinical manifestations were nonspecific. All patients were treated by glucocorticoid and immune-inhibitor(alkylating agents or purine synthesis inhibitors) therapy. Because patients were complicated with other organs involved, they needed long-time treatment. Conclusions: This disease is diverse and complex, with a lack of pathognomonic symptoms. We should highly suspect eosinophilic granulomatosis with polyangiitis, when the patients present severe asthma and eosinophilia. Early detection, early treatment, and the prognosis could be better.

[Diffusion tensor imaging of the central auditory system in the elderly]

Objective:To evaluate the changes in the central auditory system of presbycusis by applying auditury brainstem response (ABR) and diffusion tensor imaging (DTI). Method:A total of twenty-five elderly subjects with expressed presbycusis, eight elderly subjects with normal hearing and fifteen healthy volunteers as young controls were enrolled in the study. Each participant was examined using ABR and DTI. ABR measures were obtained from all the subjects. The fractional anisotropy (FA) was measured at two brain regions of the auditory pathway-the inferior colliculus (IC) and Heschl's gyrus. Result:Higher FA values were recorded at the left side of the Heschl's gyrus in all three groups (P<0.05). There were no significant differences between the left and right side of the ABR results and FA values of inferior colliculus in the three groups (P>0.05). Aging increased ABR peak latencies, yet did not change the Ⅰ-Ⅴ interpeak latency interval. Comparing with the elderly subjects with normal hearing group, the wave Ⅴ latencies of the presbycusis group were prolonged (P<0.05). Comparing with the healthy control group, the FA values of the IC were reduced in both of the elderly subjects with normal hearing group and the presbycusis group (P<0.05). No statistically differences were observed between the presbycusis group and the elderly subjects with normal hearing group in the FA values of the IC (P>0.05). Significant differences between all groups were found in the FA values of the Heschl's gyrus, with higher values in the elderly subjects with normal hearing group than in the presbycusis group and even higher values in the healthy control group than in the elderly subjects with normal hearing group (P<0.05). Conclusion:The results indicated that the age-related microstructural changes exist in the central part of the auditory system, which are more obvious in the patients with presbycusis.

[Effect of connecting airbag in different filling state at the front end of piezometric tube in noninvasive ventilation circuit on man-machine synchronization]

Objective: To investigate the effect of connecting airbag in different filling state at the front end of piezometric tube in the noninvasive ventilation circuit on pressure transmission and human-machine synchronization. Method: In test 1, the airbag was connected to a piezometric tube which was placed in a closed container, the filling state of the airbag was regulated, and the pressure inside the container was changed to observe the corresponding pressure change in the piezometric tube. In test 2, the airbag in different filling state was connected at the front end of piezometric tube in noninvasive ventilation circuit. Twelve subjects were connected to the ventilator such that dynamic changes in the pressure inside the mask (Pmask) and piezometric tube (Ptube) could be measured. Data with normal distribution was analyzed by t test, while data with abnormal distribution was analyzed by K-W test. Results: In test 1, the pressure inside the container changed between 0 and 50 cmH(2)O(1 cmH(2)O=0.098 kPa), when the big airbag was filled at 1/5, 2/5, 3/5, 4/5, the medium-sized airbag was filled at 3/5, 4/5, 5/5, and the small airbag was filled at 4/5, the pressure inside the piezometric tube changed synchronously with the pressure inside the container with no statistically significant difference(P>0.05). In a state of no filling in the small airbag and the medium-sized airbag, and filled at 1/5 in the small airbag, the pressure inside the piezometric tube no longer changed with the pressure in the container when the pressure reached a certain level .When the small airbag was filled at 1/5, 2/5, 3/5, 5/5, the medium-sized airbag at 1/5, 2/5, and the big airbag at 5/5, and all the airbags were in the state of no filling , the difference in the pressure between the piezometric tube and the container was statistically significant. In test 2, respiratory ventilation parameters were set on 10/4 cmH(2)O-30/14 cmH(2)O , and the connecting airbag at the front end of piezometric tube in noninvasive ventilation circuit. The platform pressure in the mask was slightly higher than that in the piezometer tube, and the baseline pressure in the mask was slightly lower than that of the piezometer tube. When the big airbag was filled at 1/5, 2/5, 3/5, 4/5 and medium-sized airbag at 2/5, 3/5, 4/5, the pressure difference between Pmask and Ptube was less than 0.5 cmH(2)O, which was acceptable clinically. When the big airbag was filled at 1/5, 2/5, 3/5 and the medium-sized airbag at 2/5, 3/5, there was no significant difference in trigger work before and after connecting the airbag at the front end of the piezometric tube(P>0.05). Conclusion: Connecting the airbag at the front end of the piezometric tube could avoid the forming of condensate in piezometric tube. The airbag showed good properties of pressure conductivity under ideal size and filling state.

[Analysis of deafness-related gene mutations in 23 nonsyndromic hearing impairment families in Guangxi Zhuang Autonomous Region]

Objective:To investigate the genetic characteristics of the mutations responsible for nonsyndromic hearing loss in Guangxi Zhuang Autonomous Region, and analyze the deafness-related gene mutations in nonsyndromic hearing impairment families in this region.Method:In 23 nonsyndromic hearing impairment families,66 patients or their families were enrolled as family history group and 167 patients or their families without family histiory as control group, respectively. Deafness gene mutations were determined with deafness-related gene mutations detection kits. The mutation rates among the deafness probands, the hearing impairment patients and their audibility relatives were analyzied. Whole length sequences of the deafness-related gene were detected if there was mutation by the kits, to explore Guangxi region-specific mutation-sites.Result:Common deafness-related gene mutation rate in family history group(31.82%) was higher than that in control group(11.38%), including those that in GJB2 homozygous(21.21%), SLC26A4 homozygous (9.09%), both were higher than the control group (GJB2 homozygous 5.99%, SLC26A4 homozygous 3.59%) . The rate of common deafness-related gene mutations in the deafness probands was 34.78%, in the hearing impairment patients was 30.56%, in their audibility relatives was 29.63%, all of which were higher than those in the control group. We found three rarely seen mutations, SLC26A4 IVS11+47T>C, 1548insC and GJB2 109 A>G, by detecting the whole-length sequences of the deafness-related gene.Conclusion:The results indicated that GJB2 and SLC26A4 were the most frequent mutant genes in Guangxi region. Analysis of the individual family were helpful to linkage the mutations and the deafness.

[Hemoptysis in adults with bronchiectasis: correlation with disease severity and exacerbation risk]

Objective: To investigate the association between hemoptysis and disease severity and risks of acute exacerbations in patients with bronchiectasis. Methods: Between September 2012 and January 2014, we recruited 148 patients (56 males, 92 females, mean age: 44.6 years) with clinically stable bronchiectasis, who were classified into hemoptysis group (36 males, 70 females, mean age: 45.6 years) and non-hemoptysis group (20 males, 22 females, mean age: 41.8 years). We inquired the past history, and evaluated chest imaging characteristics, lung function, cough sensitivity assessed using capsaicin cough challenge tests, and airway inflammation. We also performed a 1-year follow-up to evaluate whether patients with hemoptysis would have greater risk of having acute exacerbations. Results: In the hemoptysis group, median 24-hour sputum volume was 20.0 ml, median Bronchiectasis Severity Index (BSI) was 7.0, median bronchiectatic lobes was 4.0, median chest CT score was 7.0, the geometric mean for eliciting 5 coughs following capsaicin cough sensitivity (C5) was 77 μmol/L, 67 cases (63%) had cystic bronchiectasis and 52 cases (49%) had pulmonary cavity shown on chest CT, and 35 cases (33%) had Pseudomonas aeruginosa colonization. In the non-hemoptysis group, median 24-hour sputum volume was 5.0 ml, median BSI was 4.0, median bronchiectatic lobes was 3.0, median chest CT score was 5.0, 15 cases (36%) had cystic bronchiectasis and 10 cases (24%) had pulmonary cavity, the geometric mean for C5 was 212 μmol/L, and 4 cases (10%) had Pseudomonas aeruginosa colonization. All the above parameters differed significantly between the hemoptysis and the non-hemoptysis group (P<0.05). In the hemoptysis group, 29 patients with pulmonary cavity (27%) had reported the use of intravenous antibiotics, and 44 cases (42%) had at least one hospitalization within the previous 2 years. In the non-hemoptysis group, 8 cases (19.0%) had reported the use of intravenous antibiotics, and 8 cases (19.0%) reported hospitalization within 2 years. A prior history of hemoptysis was associated with a greater risk of experiencing bronchiectasis exacerbations during follow-up, after adjusting for age, sex, smoking status and BSI (62 cases in the hemoptysis group, 18 cases in the non-hemoptysis group, χ(2)=16.06, P=0.03). In a multivariate model, cystic bronchiectasis was the sole risk factor for hemoptysis; 67 cases which accounted for 63% of patients in the hemoptysis group and 15 cases which accounted for 36% of patients in the non-hemoptysis group, odds ratio: 2.84, 95% confidence interval: 1.00-8.14, P=0.05 . Conclusions: In this study, 72% of bronchiectasis patients had experienced hemoptysis, which was associated with the severity of bronchiectasis. Patients with a prior history of hemoptysis had a greater risk of acute exacerbations during follow-up than those without.

[Effects of noninvasive proportional assist vs pressure support ventilation on respiratory work in chronic obstructive pulmonary disease patients with hypercapnia]

Objective: To investigate the effect of noninvasive proportional assist ventilation (PAV) on respiratory work in chronic obstructive pulmonary disease(COPD) patients, in comparison to noninvasive pressure support ventilation(PSV). Methods: Ten severe COPD patients with hypercapnia during acute exacerbation were examined. The baseline inspiratory pressure of PSV (PS) and the assistance level of PAV(PA) were titrated by patients' tolerance. In addition to the baseline PS and PA, an additional decrease by 25% (PS-=75% PS, PA-=75% PA) or increase by 25% (PS+ =125% PS, PA+ =125% PA) of the assist level were applied to the patients. After the assessment of unassisted spontaneous breathing (SB), the patient was placed on the 6 levels of noninvasive-PSV and noninvasive-PAV in random sequence. Each level lasted at least 20 minutes. Respiratory rate (RR), tidal volume (Vt), and respiratory work(Wex, Wip and Wv) were measured. Asynchrony index (AI) was calculated. Results: During ventilation, Vt was significantly higher with each assist level than with SB. The Vt was significant increased with PS+ than with PA+ . An increase in expiratory work(Wex) and decrease in inspiratory work(Wip) were observed respectively, with the increasing assist level. The inspiratory muscles assessed by Wip were more unloaded at PS compared with PA [PS: (1.59±1.27) J/min vs PA: (4.99±3.48) J/min P<0.01]. However, the Wex was significantly higher with PS+ than with PA+ [PS+ : (1.17±0.54) J/min vs PA+ : (0.49±0.56)J/min, P<0.01]. The AI was increased with the increasing assist level of PSV [PS-: (0.46±0.57)%, PS: (1.36±1.24)% PS+ : (5.26±4.77)]. No asynchrony events were observed at PA- and PA. "Runaway" (expiratory asynchrony) was observed during PA+ [AI: (2.62±2.72)%]. Conclusions: Noninvasive-PAV can increase the Vt and decrease the Wip of the COPD patients with hypercapnia and avoid the over-assistance. The "Runaway" will occur at assist level higher than that set by tolerance. Physiological data can monitor the patient's responses and the ventilator-patient interaction, which may provide objective criteria for ventilator setting.

[Analysis of the SLC26A4 mutation from 230 deafness patients in Guangxi region]

Objective:To investigate the mutation characteristics of SLC26A4 gene from 230 hearing loss patients in Guangxi region.Method:Two hundred thirty patients with hearing loss were enrolled in the study. Eight mutation sites in SLC26A4 gene were tested; the types of gene mutation and the inner ear CT features of the mutationpositive patients were analyzed.Result:Among 230 deafness patients,the total mutation rate of SLC26A4 gene is 2.61%(6/230). The types of gene mutation include SLC26A4 IVS7-2A> G heterozygous in 2 case(0.87%).1226G> A homozygous in 1 cases(0.43%),IVS7-2A>G，IVS11+47T>C and 1548insC mutations in 2 cases(0.87%).Conclusion:The mutation rate of SLC26A4 gene in Guangxi region is lower than the national average level. The main mutation type in Guangxi region is SLC26A4 IVS7 2A>G. In this study, two gene mutations (SLC26A4 IVS11+47T> C and 1548insC) are firstly found, suggesting that some rare mutation types of SLC26A4 may exist in patients living in Guangxi region.

[The influence of condensate in the piezometric tube on patient ventilator interaction during noninvasive positive pressure ventilation]

OBJECTIVE

To study the effects of condensate in the piezometric tube on patient ventilator interaction during noninvasive positive pressure ventilation.

METHODS

Eleven healthy adults volunteered to receive noninvasive positive pressure ventilation. Different capacity of physiological saline was injected gradually into the piezometric tube until the volunteers could not trigger the ventilator or the total volume of the water reached 1.5 ml. The dynamic changes of the pressure of mask(Pmask), piezometric tube near mask (Ppro), piezometric tube near breathing machine(Pdis), and the flow were observed.

RESULTS

With increasing volume of saline injected, the trigger time TItri(Pmask) increased from 0.09(0.07-0.11) to 0.31(0.22-0.39)s, the trigger pressure TPtri(Pmask) increased from 0.26(0.15-0.33) to 2.29(1.76-3.09)cmH2O, and the pressure-time product PTP (Pmask) increased from 0.02(0.01-0.03) to 0.55(0.41-0.68) cmH2O·s. Ineffective triggering rate increased from 0 up to 9 times/min, and spurious triggering rate increased from 0 up to 33 times/min. The plateau pressure of Pmask and Ppro exceeded the preset parameters, increased significantly as compared with 0 ml, from (9.74±0.34)to (15.79±3.10) cmH2O and from(9.80±0.31) to(15.44±3.47) cmH2O. The change of plateau pressure of Pdis was not significant [from (9.85±0.29)to (12.58±2.64)cmH2O]. The baseline pressure of Pmask, Ppro and Pdis changed from (3.67±0.36) to (8.40±3.22) cmH2O, from (3.71±0.32) to (8.13±3.55) cmH2O and from( 3.77±0.32) to (5.36±1.25) cmH2O, respectively. The pressure fluctuation of platform of Pmask increased significantly compare with 0 ml, from 0.60(0.48-0.71) to 7.94(7.11-8.63)cmH2O. The frequency of fluctuation of platform increased as many as 7 times during a single respiratory period. The time when the pressure of the Pdis began to change was delayed to Pmask and Ppro, 0.11(0.08-0.12)s compared with 0 ml.

CONCLUSION

Condensate in the piezometric tube during noninvasive positive pressure ventilation could influence patient-ventilator synchrony. To improve patient ventilator interaction in noninvasive positive pressure ventilation, condensate in the piezometric tube should be avoided.

Naringin protects against anoxia/reoxygenation-induced apoptosis in H9c2 cells via the Nrf2 signaling pathway

Naringin (Nar) is a major and active flavanone glycoside derivative of several citrus species. The antioxidant properties of Nar have an important function in its cardioprotective effects in various models. However, the effects of Nar on Nrf2 activation and the expression of its downstream genes in myocardial cells are yet to be elucidated. This study was designed to investigate the protective effects of Nar against anoxia/reoxygenation (A/R)-induced injury in H9c2 cells and determine its effects on the activity of Nrf2 and the expression of phase II antioxidant enzymes. H9c2 cells were pretreated with Nar for 6 h before exposure to A/R. A/R treatment severely injured the H9c2 cells, which was accompanied by apoptosis. Nar also suppressed the A/R-induced mitochondrial membrane depolarization and caspase-3 activation. Nar pretreatment significantly reduced the apoptotic rate by enhancing the endogenous anti-oxidative activity of superoxide dismutase, glutathione peroxidase, and catalase, thereby inhibiting intracellular reactive oxygen species generation. Moreover, the presence of Nar alone in H9c2 cells increased the nuclear translocation of Nrf2 in a dose- and time-dependent manner, as well as consistently increased the protein levels of heme oxygenase (HO-1) and glutamate cysteine ligase (GCLC). Nar increased the phosphorylation of ERK1/2, PKCδ, and AKT. However, the Nar-mediated Nrf2 activation and cardioprotection were abolished through the genetic silencing of Nrf2 by siRNA and partially inhibited by specific inhibitors of ERK1/2, PKCδ, and AKT. Therefore, Nar provided cardioprotection by inducing the phosphorylation of ERK1/2, PKCδ, and AKT, which subsequently activated Nrf2 and its downstream genes.

Comparison of single distance phase retrieval algorithms by considering different object composition and the effect of statistical and structural noise

Phase retrieval is a technique for extracting quantitative phase information from X-ray propagation-based phase-contrast tomography (PPCT). In this paper, the performance of different single distance phase retrieval algorithms will be investigated. The algorithms are herein called phase-attenuation duality Born Algorithm (PAD-BA), phase-attenuation duality Rytov Algorithm (PAD-RA), phase-attenuation duality Modified Bronnikov Algorithm (PAD-MBA), phase-attenuation duality Paganin algorithm (PAD-PA) and phase-attenuation duality Wu Algorithm (PAD-WA), respectively. They are all based on phase-attenuation duality property and on weak absorption of the sample and they employ only a single distance PPCT data. In this paper, they are investigated via simulated noise-free PPCT data considering the fulfillment of PAD property and weakly absorbing conditions, and with experimental PPCT data of a mixture sample containing absorbing and weakly absorbing materials, and of a polymer sample considering different degrees of statistical and structural noise. The simulation shows all algorithms can quantitatively reconstruct the 3D refractive index of a quasi-homogeneous weakly absorbing object from noise-free PPCT data. When the weakly absorbing condition is violated, the PAD-RA and PAD-PA/WA obtain better result than PAD-BA and PAD-MBA that are shown in both simulation and mixture sample results. When considering the statistical noise, the contrast-to-noise ratio values decreases as the photon number is reduced. The structural noise study shows that the result is progressively corrupted by ring-like artifacts with the increase of structural noise (i.e. phantom thickness). The PAD-RA and PAD-PA/WA gain better density resolution than the PAD-BA and PAD-MBA in both statistical and structural noise study.

Guideline-discordant androgen deprivation therapy in localized prostate cancer: patterns of use in the medicare population and cost implications

Background Androgen deprivation therapy (ADT) in localized prostate cancer improves overall survival and is recommended by National Comprehensive Cancer Network guidelines in certain situations. However, ADT is without benefit in other situations and can actually cause harm. This study examines recent trends in the ADT use and quantifies the cost of guideline-discordant ADT. Patients and methods Patients, aged 66-80 years, in the Surveillance Epidemiology and End Results-Medicare database with non-metastatic prostate cancer diagnosed between 2004 and 2007 were included for analysis. Prostate-specific antigen, Gleason score, and stage were used to define D'Amico risk categories. Logistic regression was used to examine factors associated with guideline-discordant ADT. Annual direct cost was estimated using 2011 Medicare reimbursement for ADT. Results Of 28 654 men included, 12.4% received guideline-discordant ADT. In low-risk patients, 14.9% received discordant ADT, mostly due to simultaneous ADT with radiation. Discordant use was seen in 7.3% of intermediate and 14.9% of high-risk patients, mostly from ADT as primary therapy. The odds of receiving guideline-discordant ADT decreased over time (2007 versus 2004; OR 0.69; 95% CI 0.62-0.76). The estimated annual direct cost from discordant ADT is $42 000 000. Conclusion Approximately one in eight patients received ADT discordant with published guidelines. Elimination of discordant use would result in substantial savings.

Phase retrieval in quantitative x-ray microtomography with a single sample-to-detector distance

Phase retrieval extracts quantitative phase information from x-ray propagation-based phase-contrast images. Notwithstanding inherent approximations, phase retrieval using a single sample-to-detector distance (SDD) is very attractive, because it imposes no setup complications or additional radiation dose compared to absorption-based imaging. Considering the phase-attenuation duality (ε=δ/β, where ε is constant), a simple absorption correction factor is proposed for the modified Bronnikov algorithm in x-ray propagation-based phase-contrast computed tomography (PPCT). Moreover, a practical method for calculating the optimal ε value is proposed, which requires no prior knowledge of the sample. Tests performed on simulation and experimental data successfully distinguished different materials in a quasihomogeneous and weakly absorbing sample from a single SDD-PPCT data point.

Greater than 10-year results of red-white longitudinal meniscal repairs in patients 20 years of age or younger

BACKGROUND

A prospective longitudinal investigation was conducted to determine the long-term outcome of single longitudinal meniscal repairs extending into the central avascular region in patients aged 20 years or younger.

PURPOSE

To determine the long-term success rate and reoperation rate of meniscal repairs extending into the avascular zone.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Thirty-three meniscal repairs were performed using an inside-out multiple vertical divergent suture technique. A concomitant anterior cruciate ligament reconstruction was done in 18 patients. The mean follow-up was 16.8 years (range, 10.1-21.9 years). The long-term success rate was determined in 29 repairs (88%) by the presence of normal or nearly normal parameters from 2 validated knee rating systems, assessment of magnetic resonance imaging and weightbearing posteroanterior radiographs by independent physicians, and follow-up arthroscopy when required. A 3 Tesla magnetic resonance imaging scanner with cartilage-sensitive pulse sequences was used, and T2 mapping was performed. A comparison was made between the short-term (mean, 4 years) and long-term outcomes.

RESULTS

Eighteen (62%) of the meniscal repairs had normal or nearly normal characteristics in all of the parameters assessed. Six repairs (21%) required partial arthroscopic resection, 2 had loss of joint space on radiographs, and 3 that were asymptomatic failed according to magnetic resonance imaging criteria, for a total of 11 documented failures (38%). There was no significant difference in the mean articular cartilage T2 scores in the healed menisci between the involved and contralateral tibiofemoral compartments in the same knee. There were no significant differences between short- and long-term evaluations for pain, swelling, jumping, patient knee condition rating, or the overall Cincinnati rating score.

CONCLUSIONS

A chondroprotective joint effect was demonstrated in the healed menisci repairs, which warrants the procedure in select patients. The long-term evaluation of the anterior cruciate ligament-reconstructed knees with concurrent successful meniscal repairs demonstrated a low rate of radiographic arthritis.

Cough reflex sensitivity is increased in guinea pigs with parainfluenza virus infection

The purpose of this study was to investigate for the change in cough reflex sensitivity (CRS) caused by parainfluenza virus type 3 (PIV3) infection. Guinea pigs were randomized into a vehicle control, an asthma control, or 1 of 4 PIV3-inoculated groups (referred to as postinfection day [PID] 6, 12, 28, and 42 groups). Evidence of viral protein and nucleic acid within the lung confirmed successful PIV3 infection. Plethysmography was used to assess CRS and airway reaction and airway inflammation was assessed via bronchoalveolar lavage fluid cytology and lung histopathology. Compared with the vehicle control group, CRS was significantly increased in all PID groups (P <.05) in concert with an obvious airway hyperresponsiveness in the PID 6 group. Though a small increase in CRS in the asthma control group was noted, it was not significant compared to the vehicle control group. Total cell counts from the bronchoalveolar lavage fluid of all PIV3-inoculated groups increased markedly and the number of lymphocytes was significantly increased in the PID 6 and PID 12 groups. The lung pathology of PIV3-inoculated animals showed airway inflammation without pneumonia in the acute infectious phase. The temporal and spatial variation of CRS may be the essential mechanism of cough caused by PIV3.

Repair of complex and avascular meniscal tears and meniscal transplantation

A functional meniscus is critical to the long-term health of the knee joint. The repair of meniscal tears that extend into the central avascular region requires understanding the appropriate indications, contraindications, surgical techniques, and postoperative rehabilitation protocols. An inside-out repair technique using multiple vertical divergent sutures with an accessory posteromedial or posterolateral incision is recommended for optimal stability. In young, active patients, the risk of repair failure and the need for revision are outweighed by the benefit of meniscal preservation. Although many meniscal tears are repairable, not all are salvageable, especially if considerable tissue damage has occurred. The goals of transplantation of human menisci are to restore partial load-bearing meniscal function, decrease patient symptoms, and provide chondroprotective effects. Clinical studies have shown that meniscal transplantation decreases tibiofemoral joint pain in the short term. The procedure remains in an evolving state with an unpredictable long-term outcome; however, most meniscal transplants gradually deteriorate, tear, or shrink in size over time, thereby losing the ability to provide function. The current goal is to provide short-term benefits to the patient until a superior meniscal transplant is clinically available.

The radiology of referred otalgia

Pain referred to the ear is a well-documented phenomenon, which can be due to a multitude of disease processes. With the recent and rapid progression of CT and MR imaging technology, radiologists have played an increasing role in solving this potentially difficult diagnostic dilemma. Essentially any pathology residing within the sensory net of cranial nerves V, VII, IX, and X and the upper cervical nerves C2 and C3 can potentially cause referred otalgia. This article will attempt to outline the various sensorineural pathways that dually innervate the ear and other sites within the head and neck, as well as discuss various disease processes that are known to result in referred otalgia.

A new dynamic foot abduction orthosis for clubfoot treatment

Recurrent clubfoot deformity after successful initial correction with the use of the Ponseti method continues to be a common problem and is often caused by noncompliance with wear of the traditional foot abduction brace. The purpose of this study was to assess the results of a newly designed dynamic foot abduction orthosis in terms of (1) parental compliance and (2) effectiveness in preventing recurrent clubfoot deformities. Twenty-eight patients (49 clubfeet) who were treated with a dynamic foot abduction orthosis in accordance with the Ponseti method were included in this study. Of the 28 patients, 18 had idiopathic clubfeet (31 clubfeet), 2 had complex idiopathic clubfeet (4 clubfeet), 5 had myelodysplasia (8 clubfeet), and 3 were syndromic (6 clubfeet). The mean duration of follow-up was 29 months (range, 24-36 months). Noncompliance was reported in only 2 (7.1%) of the 28 patients in the new orthosis compared with the authors' previously reported 41% (21/51) noncompliance rate in patients treated with the use of the traditional foot abduction brace. The two patients in this study, in which parents were noncompliant with orthosis wear, developed recurrent deformities. There were 2 patients (7%) who experienced skin blistering in the new orthosis compared with 12 (23.5%) of 51 patients who experienced blistering with the use of traditional abduction brace in the authors' previously reported study. Logistic regression modeling compliance and recurrence revealed that noncompliance with the foot abduction orthosis was most predictive of recurrence of deformity (odds ratio, 27; 95% confidence interval, 2.2-326; P = 0.01). The articulating foot abduction orthosis is well tolerated by patients and parents and results in a higher compliance rate and a lower complication rate than what were observed with the traditional foot abduction orthosis.

Troublesome stress fractures of the foot and ankle

Athletes engaged in repetitive activity with recent increases in training or competition are at risk for stress fractures of the foot and ankle. Physical and radiographic findings are often unremarkable and diagnosis may be difficult. Although many of these injuries may be managed symptomatically, certain types of stress fractures are at higher risk for delayed union, nonunion, or refracture without aggressive immobilization or surgical fixation.