Peak oxygen uptake and respiratory muscle performance in patients with chronic obstructive pulmonary disease: Clinical findings and implications

The maximal oxygen uptake (VO_2max) is the gold standard measure of aerobic exercise capacity and is an important outcome measure in patients with chronic obstructive pulmonary disease (COPD). And respiratory muscle performance is also an important functional parameter for COPD patients. In addition to the traditional respiratory muscle strength test, the Test of Incremental Respiratory Endurance has recently been introduced and validated in patients with COPD. However, the relationship between VO₂ and respiratory muscle performance in COPD is not well understood. Therefore, this study investigated the correlations among VO₂ and respiratory muscle performance and other functional markers in COPD. A total of 32 patients with COPD were enrolled. All study participants underwent the following assessments: cardiopulmonary exercise test, pulmonary function test, respiratory muscle strength test, peripheral muscle strength test, and bioelectrical impedance analysis. When comparing VO_2peak and respiratory muscle parameters, the sustained maximal inspiratory pressure (SMIP) was the only factor with a significant relationship with VO_2peak. Among other functional parameters, the forced expiratory volume in one second (FEV₁) showed the strongest correlation with VO_2peak. It was followed by phase angle values of lower limbs, leg extension peak torque, age, and total skeletal muscle mass. When comparing respiratory muscle performance with other functional parameters, the SMIP showed the strongest correlation with hand grip strength, followed by peak cough flow, forced vital capacity, maximal inspiratory pressure, and FEV₁. The results showed that the SMIP was more significantly correlated with VO_2peak than the static measurement of respiratory muscle strength. This suggests that TIRE may be a useful assessment tool for patients with COPD. Additionally, FEV₁ and other functional markers were significantly correlated with VO_2peak, suggesting that various parameters may be used to evaluate aerobic power indirectly.     

Endoscopist-Driven Sedation Practices in South Korea: Re-evaluation Considering the Nationwide Survey in 2019

Background/AimsThis study aimed to determine changes in endoscopist-driven sedation practices 5 years after the first nationwide survey in 2014 by the Korean Society of Gastrointestinal Endoscopy (KSGE).MethodsA 59-item survey covering current practices was electronically mailed to all members of the KSGE in 2019.ResultsIn total, 955 (12.8%) out of 7,486 questionnaires were returned. A total of 738 (77.7%) out of 955 respondents attended dedicated sedation education programs. The American Society of Anesthesiologists class was recorded by 464 (51.2%) out of 907 respondents. The recording rate was higher in respondents who completed sedation education (p=0.014) and worked in general or tertiary hospitals (p<0.001). Compared to that reported in the previous survey, the reported use of propofol was higher in 2019. The respondents had higher satisfaction scores for propofol-based sedation compared with midazolam monotherapy (p<0.001). The rates of oxygen supplementation (p<0.001) and oxygen saturation level monitoring (p<0.001) during sedative endoscopy were higher in 2019 than in the previous survey. A total of 876 (98.4%) out of 890 respondents reported a separate recovery bay, and 615 (70.5%) out of 872 respondents reported that personnel were assigned solely to the recovery bay.ConclusionsEndoscopist-driven sedation and monitoring practices in 2019 were significantly different than those in 2014. The respondents favored propofol-based sedation and utilized oxygen supplementation and monitoring of O₂ saturation more frequently in 2019 than in 2014. (Gut Liver, Published online August 1, 2022)     

Methylprednisolone Inhibits Autophagy of Vascular Endothelial Cells in Rat Femoral Head Via PI3K/Akt/mTOR Pathway

ObjectiveTo study the relationship between vascular endothelial cells (VEC) and autophagy, and its regulatory mechanism in steroid‐induced avascular necrosis of the femoral head (SANFH).MethodsIn cell experiment, VEC were isolated and cultured from the femoral head of Sprague–Dawley rats and divided into three groups: blank control group (Ctrl), methylprednisolone group (MP), and methylprednisolone+mTOR‐shRNA group (MP + shmTOR). The autophagy formation was observed by transmission electron microscope. The mRNA expression of PI3K, Akt, mTOR, Beclin1 and MAP1LC3 was detected by RT‐PCR and the protein expression was detected by Western blot and immunofluorescence. Expression of the damage marker 6‐keto‐PGF1α was detected by the ELISA method. In vivo experiment, after establishing the model, the grouping method was the same as cell experiment. Autophagosomes were observed by same method, and the expression of related factors was detected by the same method in cell experiment.ResultsIn the cell experiment, autophagosomes in the MP group were significantly lower than in the Ctrl group, and the autophagosomes in the MP + shmTOR group were intermediate between two groups (P < 0.05). The mRNA expression levels of PI3K, Akt and mTOR in the MP group were significantly higher than in the Ctrl group, while the MP+ shmTOR group presented intermediate levels between these groups (average gray value were 3837.90, 2996.30, 3005.60, F = 428.64, P < 0.05). MRNA expression levels of Beclin1 and MAP1LC3 in the MP group were significantly lower than that in Ctrl group (P < 0.05). The content of 6‐keto‐PGF1α in the MP + shmTOR group was higher than in the Ctrl group and lower than in the MP group at the evaluated time intervals (average absorbance value were 104.98, 206.83, 145.91, F = 352.83, P < 0.01). In vivo experiment, the content of 6‐Keto‐PGF1α in the hormone group increased as time went on; the mTOR‐si group was higher than that in control group, but lower than that in the hormone group (P < 0.01). The mRNA expressions of Beclin1 and MAP1LC3 in the control group were higher than those in the hormone group, while the mRNA expressions of PI3K, Akt and mTOR were lower than those in the mTOR‐si group (P < 0.05).ConclusionThe steroid inhibited the physiological protective effect of autophagy on SANFH by increasing the expression of PI3K/Akt/mTOR signaling pathway related factors and decreasing the expression of Beclin1 and MAP1LC3 in the femoral head VEC.     

Epidemiological Trends of Pediatric Inflammatory Bowel Disease in Korea: A Multicenter Study of the Last 3 Years Including the COVID-19 Era

BackgroundStudies on how the coronavirus pandemic has affected pediatric inflammatory bowel disease (PIBD) are lacking. We aimed to investigate the trends in epidemiology, characteristics, initial management, and short-term outcomes of PIBD in South Korea over the recent three years including the era of coronavirus disease 2019 (COVID-19).MethodsThis multicenter study retrospectively investigated temporal trends in the epidemiology of PIBD in Korea. Annual occurrences, disease phenotypes, and initial management at diagnosis were analyzed from January 2018 to June 2021.ResultsA total of 486 patients from 17 institutions were included in this epidemiological evaluation. Analysis of the occurrence trend confirmed a significant increase in PIBD, regardless of the COVID-19 pandemic. In Crohn’s disease, patients with post-coronavirus outbreaks had significantly higher fecal calprotectin levels than those with previous onset (1,339.4 ± 717.04 vs. 1,595.5 ± 703.94, P = 0.001). Patients with post-coronavirus-onset ulcerative colitis had significantly higher Pediatric Ulcerative Colitis Activity Index scores than those with previous outbreaks (48 ± 17 vs. 36 ± 15, P = 0.004). In the initial treatment of Crohn’s disease, the use of 5-aminosalicylic acid (5-ASA) and steroids significantly decreased (P = 0.006 and 0.001, respectively), and enteral nutrition and the use of infliximab increased significantly (P = 0.045 and 0.009, respectively). There was a significant increase in azathioprine use during the initial treatment of ulcerative colitis (P = 0.020).ConclusionRegardless of the COVID-19 pandemic, the number of patients with PIBD is increasing significantly annually in Korea. The initial management trends for PIBD have also changed. More research is needed to establish appropriate treatment guidelines considering the epidemiological and clinical characteristics of Korean PIBD.     

Relative Effectiveness of COVID-19 Vaccination in Healthcare Workers: 3-Dose Versus 2-Dose Vaccination

The omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to have high infectivity and is more likely to evade vaccine immunity. However, booster vaccination is expected to strengthen cross-reactive immunity, thereby increasing the vaccine effectiveness (VE). This study aimed to evaluate the relative VE of the 3-dose (booster) vaccination compared with the 2-dose primary series vaccination in healthcare workers during omicron variant-dominant periods. During the omicron-dominant period from February 1, 2022 to February 28, 2022, a 1:1 matched case-control study was conducted. Healthcare workers with positive SARS-CoV-2 test results were classified as positive cases, whereas those with negative results served as controls. Compared with the 2-dose primary series vaccination, booster vaccination with mRNA vaccine showed moderate VE (53.1%). However, in multivariate analysis including the time elapsed after vaccination, the significant VE disappeared, reflecting the impact of recent vaccination rather than the third dose itself.     

Epithelial Autoantigen-Specific IgG Antibody Enhances Eosinophil Extracellular Trap Formation in Severe Asthma

PurposeThere have been autoimmune mechanisms for the pathogenesis of severe asthma (SA) involving epithelial autoantigen-specific antibodies. This study aimed to find the function of these antibodies in the formation of eosinophil extracellular traps (EETs), contributing to the development of SA.MethodsPatients with SA (n = 11), those with patients with nonsevere asthma (NSA, n = 41), and healthy controls (HCs, n = 26) were recruited to evaluate levels of epithelial antigens and autoantigen-specific antibodies. Moreover, the significance of epithelial autoantigen-specific antibodies in association with EET production was investigated ex vivo and in vivo.ResultsSignificantly higher levels of serum cytokeratin (CK) 18 and CK18-specific IgG were observed in patients with SA than in those with NSA (P = 0.001 and P = 0.031, respectively), while no differences were found in serum CK19 or CK19-specific immunoglobulin G (IgG). Moreover, levels of serum CK18 were positively correlated with total eosinophil counts (r = 0.276, P = 0.048) in asthmatics, while a negative correlation was noted between levels of serum CK18 and forced expiratory volume in 1 second (FEV1) %. In the presence of CK18-specific IgG, peripheral eosinophils from asthmatics released EETs, which further increased CK18 production from airway epithelial cells. In severe asthmatic mice, CK18 expression and CK18-specific IgG production were enhanced in the lungs, where EET treatment enhanced CK18 expression and CK18-specific IgG production, either of which was not suppressed by dexamethasone.ConclusionsThese suggest that EETs could enhance epithelial autoantigen (CK18)-induced autoimmune responses, further stimulating EET production and type 2 airway responses, which is a new therapeutic target for SA.     

Real-Time Light-Guided Vocal Fold Injection via the Cricothyroid Membrane in Unilateral Vocal Fold Paralysis: A Human Pilot Study

Objectives. Vocal fold injection (VFI) via the cricothyroid (CT) membrane is used to treat various diseases affecting the vocal folds. The technical challenges of this technique are mainly related to the invisibility of the needle. Real-time light-guided VFI (RL-VFI) was recently developed for injection under simultaneous light guidance in the CT approach. Herein, we present the first clinical trial of RL-VFI, in which we investigated the feasibility and safety of this new technique in unilateral vocal fold paralysis (VFP).Methods. This prospective pilot study enrolled 40 patients, who were treated with RL-VFI for unilateral VFP between September 2020 and August 2021. Adverse events were monitored during the procedure and for 4 weeks postoperatively. The Voice Handicap Index-10, the GRBAS (grade, roughness, breathiness, asthenia, and strain) scale, aerodynamic studies, and acoustic analyses were evaluated to compare the voice improvement after 4 weeks with the baseline values.Results. The needle tip was intuitively identified by the red light. The mean procedure time was 95.6±40.6 seconds for the initial injection, while the additional injection required 79.2±70.5 seconds. The injection was performed under light guidance without additional manipulation after the needle reached the intended point. No acute or delayed adverse events were reported. Among the 40 patients, 36 completed voice analyses after 4 weeks. Subjective and objective voice parameters, including the Voice Handicap Index-10, GRBAS scale, maximum phonation time, mean expiratory airflow, fundamental frequency, jitter, shimmer, and noise-to-harmonics ratio improved significantly after RL-VFI (P<0.05), while the expiratory volume was maintained.Conclusion. RL-VFI is feasible and safe for treating patients with unilateral VFP. This technique is anticipated to improve the precision and safety of the CT approach in the treatment of unilateral VFP. This study provides a rationale for further structured clinical studies.     

Use of Artificial Intelligence for Reducing Unnecessary Recalls at Screening Mammography: A Simulation Study

ObjectiveTo conduct a simulation study to determine whether artificial intelligence (AI)-aided mammography reading can reduce unnecessary recalls while maintaining cancer detection ability in women recalled after mammography screening.Materials and MethodsA retrospective reader study was performed by screening mammographies of 793 women (mean age ± standard deviation, 50 ± 9 years) recalled to obtain supplemental mammographic views regarding screening mammography-detected abnormalities between January 2016 and December 2019 at two screening centers. Initial screening mammography examinations were interpreted by three dedicated breast radiologists sequentially, case by case, with and without AI aid, in a single session. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and recall rate for breast cancer diagnosis were obtained and compared between the two reading modes.ResultsFifty-four mammograms with cancer (35 invasive cancers and 19 ductal carcinomas in situ) and 739 mammograms with benign or negative findings were included. The reader-averaged AUC improved after AI aid, from 0.79 (95% confidence interval [CI], 0.74–0.85) to 0.89 (95% CI, 0.85–0.94) (p < 0.001). The reader-averaged specificities before and after AI aid were 41.9% (95% CI, 39.3%–44.5%) and 53.9% (95% CI, 50.9%–56.9%), respectively (p < 0.001). The reader-averaged sensitivity was not statistically different between AI-unaided and AI-aided readings: 89.5% (95% CI, 83.1%–95.9%) vs. 92.6% (95% CI, 86.2%–99.0%) (p = 0.053), although the sensitivities of the least experienced radiologists before and after AI aid were 79.6% (43 of 54 [95% CI, 66.5%–89.4%]) and 90.7% (49 of 54 [95% CI, 79.7%–96.9%]), respectively (p = 0.031). With AI aid, the reader-averaged recall rate decreased by from 60.4% (95% CI, 57.8%–62.9%) to 49.5% (95% CI, 46.5%–52.4%) (p < 0.001).ConclusionAI-aided reading reduced the number of recalls and improved the diagnostic performance in our simulation using women initially recalled for supplemental mammographic views after mammography screening.