Endobronchial valves for emphysema and persistent air-leak: 10-year experience in an Asian country.

BACKGROUND: Endobronchial valve (EBV) therapy, a validated method for bronchoscopic lung volume reduction (BLVR) in severe emphysema, has been explored for persistent air-leak (PAL) management. However, its effectiveness and safety in the Asian population require further real-world evaluation. In this study, we assessed the outcomes of treatment with EBV within this demographic. METHODS: We conducted a retrospective analysis of medical records from 11 Korean centers. For the emphysema cohort, inclusion criteria were patients diagnosed with emphysema who underwent bronchoscopy intended for BLVR. We assessed these patients for clinical outcomes of chronic obstructive pulmonary disease. All patients with PAL who underwent treatment with EBV were included. We identified the underlying causes of PAL and evaluated clinical outcomes after the procedure. RESULTS: The severe emphysema cohort comprised 192 patients with an average age of 70.3 years, and 95.8% of them were men. Ultimately, 137 underwent treatment with EBV. Three months after the procedure, the BLVR group demonstrated a significant improvement in forced expiratory volume in 1 s (+160 mL vs. +30 mL; P = 0.009). Radiographic evidence of lung volume reduction 6 months after BLVR was significantly associated with improved survival (adjusted hazard ratio 0.020; 95% confidence interval 0.038-0.650; P = 0.010). Although pneumothorax was more common in the BLVR group (18.9% vs. 3.8%; P = 0.018), death was higher in the no-BLVR group (38.5% vs. 54.5%, P = 0.001), whereas other adverse events were comparable between the groups. Within the subset of 18 patients with PAL, the predominant causes of air-leak included spontaneous secondary pneumothorax (44.0%), parapneumonic effusion/empyema (22.2%), and post-lung resection surgery (16.7%). Following the treatment, the majority (77.8%) successfully had their chest tubes removed. Post-procedural complications were minimal, with two incidences of hemoptysis and one of empyema, all of which were effectively managed. CONCLUSIONS: Treatment with EBV provides substantial clinical benefits in the management of emphysema and PAL in the Asian population, suggesting a favorable outcome for this therapeutic approach.

Microlens array camera with variable apertures for single-shot high dynamic range (HDR) imaging.

We report a microlens array camera with variable apertures (MACVA) for high dynamic range (HDR) imaging by using microlens arrays with various sizes of apertures. The MACVA comprises variable apertures, microlens arrays, gap spacers, and a CMOS image sensor. The microlenses with variable apertures capture low dynamic range (LDR) images with different f-stops under single-shot exposure. The reconstructed HDR images clearly exhibit expanded dynamic ranges surpassing LDR images as well as high resolution without motion artifacts, comparable to the maximum MTF50 value observed among the LDR images. This compact camera provides, what we believe to be, a new perspective for various machine vision or mobile devices applications.

Pretreatment of rhesus monkeys with transdermal patches containing physostigmine and procyclidine: implications of the delivery system for the potential application against VX nerve agent intoxication in humans.

Physostigmine (Phs) is a reversible inhibitor of acetylcholinesterase (AChE) that penetrates the blood-brain barrier (BBB) and could be used to protect the central nervous system (CNS) against the effects of nerve agents. For prophylactic effectiveness, long, steady, and adequate inhibition of AChE activity by Phs is needed to broadly protect against the CNS effects of nerve agents. Here, we evaluated the efficacy of transdermal patches containing Phs and procyclidine (PC) as prophylactic agents. Patches (25 cm2) containing 4.4 mg Phs and 17.8 mg PC had a protective ratio of approximately 78.6-fold in rhesus monkeys challenged with VX nerve agent and given an antidote. Physiologically based pharmacokinetic model in conjunction with an indirect pharmacodynamic (PBPK/PD) was developed for Phs and scaled to rhesus monkeys. The model was able to reproduce the concentration profile and inhibitory effect on AChE of Phs in monkeys, as evidenced by correlation coefficients of 0.994 and 0.992 for 25 cm2 and 49 cm2 patches, respectively (i.e., kinetic data), and 0.989 and 0.968 for 25 cm2 and 49 cm2 patches, respectively (i.e., dynamic data). By extending the monkey PBPK/ PD model to humans, the effective human dose was predicted to be five applications of a 25 cm2 patch (i.e., 22 mg Phs), and two applications of a 49 cm2 patch (i.e., 17.4 mg Phs). Therefore, given that patch application of Phs in rhesus monkeys has a prolonged effect (namely, AChE inhibition of 19.6% for the 25 cm2 patch and 23.0% for the 49 cm2 patch) for up to 216 h, patch formulation of Phs may provide similar protection against nerve agent intoxication in humans.

Comparison of the end-of-life decisions of patients with hospital-acquired pneumonia after the enforcement of the life-sustaining treatment decision act in Korea.

BACKGROUND: Although the Life-Sustaining Treatment (LST) Decision Act was enforced in 2018 in Korea, data on whether it is well established in actual clinical settings are limited. Hospital-acquired pneumonia (HAP) is a common nosocomial infection with high mortality. However, there are limited data on the end-of-life (EOL) decision of patients with HAP. Therefore, we aimed to examine clinical characteristics and outcomes according to the EOL decision for patients with HAP. METHODS: This multicenter study enrolled patients with HAP at 16 referral hospitals retrospectively from January to December 2019. EOL decisions included do-not-resuscitate (DNR), withholding of LST, and withdrawal of LST. Descriptive and Kaplan-Meier curve analyses for survival were performed. RESULTS: Of 1,131 patients with HAP, 283 deceased patients with EOL decisions (105 cases of DNR, 108 cases of withholding of LST, and 70 cases of withdrawal of LST) were analyzed. The median age was 74 (IQR 63-81) years. The prevalence of solid malignant tumors was high (32.4% vs. 46.3% vs. 54.3%, P = 0.011), and the ICU admission rate was lower (42.9% vs. 35.2% vs. 24.3%, P = 0.042) in the withdrawal group. The prevalence of multidrug-resistant pathogens, impaired consciousness, and cough was significantly lower in the withdrawal group. Kaplan-Meier curve analysis revealed that 30-day and 60-day survival rates were higher in the withdrawal group than in the DNR and withholding groups (log-rank P = 0.021 and 0.018). The survival of the withdrawal group was markedly decreased after 40 days; thus, the withdrawal decision was made around this time. Among patients aged below 80 years, the rates of EOL decisions were not different (P = 0.430); however, mong patients aged over 80 years, the rate of withdrawal was significantly lower than that of DNR and withholding (P = 0.001). CONCLUSIONS: After the LST Decision Act was enforced in Korea, a DNR order was still common in EOL decisions. Baseline characteristics and outcomes were similar between the DNR and withholding groups; however, differences were observed in the withdrawal group. Withdrawal decisions seemed to be made at the late stage of dying. Therefore, advance care planning for patients with HAP is needed.

Trends and an Online Survey on the Use of Rigid Bronchoscopy in Korea.

BACKGROUND: Although almost all interventional pulmonologists agree that rigid bronchoscopy is irreplaceable in the field of interventional pulmonology, less is known about the types of diseases that the procedure is used for and what difficulties the operators face during the procedure. The purpose of this study is to evaluate what diseases rigid bronchoscopy is used for, whether it is widely used, and what challenges the operators face in Korea. METHODS: We enrolled 14 hospitals in this retrospective cohort of patients who underwent rigid bronchoscopy between 2003 and 2020. An online survey was conducted with 14 operators to investigate the difficulties associated with the procedure. RESULTS: While the number of new patients at Samsung Medical Center (SMC) increased from 189 in 2003-2005 to 468 in 2018-2020, that of other institutions increased from 0 to 238. The proportion of SMC patients in the total started at 100% and steadily decreased to 59.2%. The proportion of malignancy as the indication for the procedure steadily increased from 29.1% to 43.0%, whereas post-tuberculous stenosis (25.4% to 12.9%) and post-intubation stenosis (19.0% to 10.9%) steadily decreased (all P for trends < 0.001). In the online survey, half of the respondents stated that over the past year they performed less than one procedure per month. The fewer the procedures performed within the last year, the more likely collaboration with other departments was viewed as a recent obstacle (Spearman correlation coefficient, rs = -0.740, P = 0.003) and recent administrative difficulties were encountered (rs = -0.616, P = 0.019). CONCLUSION: This study demonstrated that the number of patients undergoing rigid bronchoscopy has been increasing, especially among cancer patients. For this procedure to be used more widely, it will be important for beginners to systematically learn about the procedure itself as well as to achieve multidisciplinary consultation.

Empiric Anti-Pseudomonal ß-Lactam Monotherapy Versus Fluoroquinolone Combination Therapy in Patients With Hospital-Acquired Pneumonia: A Multicenter Cohort Study With Propensity Score Matching.

BACKGROUND: There is insufficient data on the benefits of empiric antibiotic combinations for hospital-acquired pneumonia (HAP). We aimed to investigate whether empiric anti-pseudomonal combination therapy with fluoroquinolones decreases mortality in patients with HAP. METHODS: This multicenter, retrospective cohort study included adult patients admitted to 16 tertiary and general hospitals in Korea between January 1 and December 31, 2019. Patients with risk factors for combination therapy were divided into anti-pseudomonal non-carbapenem ß-lactam monotherapy and fluoroquinolone combination therapy groups. Primary outcome was 30-day mortality. Propensity score matching (PSM) was used to reduce selection bias. RESULTS: In total, 631 patients with HAP were enrolled. Monotherapy was prescribed in 54.7% (n = 345) of the patients, and combination therapy was prescribed in 45.3% (n = 286). There was no significant difference in 30-day mortality between the two groups (16.8% vs. 18.2%, P = 0.729) or even after the PSM (17.5% vs. 18.2%, P = 0.913). After the PSM, adjusted hazard ratio for 30-day mortality from the combination therapy was 1.646 (95% confidence interval, 0.782-3.461; P = 0.189) in the Cox proportional hazards model. Moreover, there was no significant difference in the appropriateness of initial empiric antibiotics between the two groups (55.0% vs. 56.8%, P = 0.898). The proportion of multidrug-resistant (MDR) pathogens was high in both groups. CONCLUSION: Empiric anti-pseudomonal fluoroquinolone combination therapy showed no survival benefit compared to ß-lactam monotherapy in patients with HAP. Caution is needed regarding the routine combination of fluoroquinolones in the empiric treatment of HAP patients with a high risk of MDR.

Is hyper-selectivity a root of Asian American children's success?

Asian immigrants' children, even those from lower-backgrounds, tend to acquire higher levels of education than other ethnoracial groups, including White natives. Asian culture is often cited as a conventional explanation. The hyper-selectivity hypothesis challenges conventional wisdom by arguing that Asian American culture is an outcome of the community resources associated with hyper-selectivity. In this study, we assess the validity of the hyper-selectivity theory by examining the association between the magnitude of hyper-selectivity measured by the proportion of the BA + degree holders among the 1st generation Asian immigrants across communities and the likelihood of school enrollment for 1.5 and 2nd + generation Asian American children. Our results cast doubt on the hyper-selectivity theory. Asian American children's school enrollment is associated with the magnitude of educational selectivity among Asian immigrants for neither high school nor college. The benefits of hyper-selectivity do not seem to be cross-class or cross Asian ethnic groups. The higher the hyper-selectivity in a community is, the larger the education gap between upper- and lower-background Asian American children. The implications of these findings are discussed.

Safety and Diagnostic Yield of Radial Probe Endobronchial Ultrasound-Guided Biopsy for Peripheral Lung Lesions in Patients with Idiopathic Pulmonary Fibrosis: A Multicenter Cross-Sectional Study.

BACKGROUND: Radial probe endobronchial ultrasound-guided transbronchial lung biopsy (RP-EBUS-TBLB) is widely used for diagnosis of peripheral lung lesions (PLLs). To date, there have been no reports regarding the clinical outcomes of RP-EBUS-TBLB for PLLs in patients with idiopathic pulmonary fibrosis (IPF). OBJECTIVES: This study was performed between October 2017 and December 2019 to identify the safety and diagnostic performance of RP-EBUS-TBLB in IPF patients. METHODS: Patients were divided into the usual interstitial pneumonia (UIP) group (n = 39, 4%), the probable UIP group (n = 12, 1%), and the noninterstitial lung disease (non-ILD) group (n = 903, 95%). RESULTS: The diagnostic yield was significantly lower in the UIP group than in the non-ILD group (62% vs. 76%; p = 0.042), but there were no significant differences between the UIP and probable UIP groups (62% vs. 83%; p = 0.293) or the probable UIP and non-ILD groups (83% vs. 76%; p = 0.741). Multivariate logistic analysis showed that the mean diameter of PLLs, positive bronchus sign on CT, and "within the lesion" status on EBUS were independently associated with success of the procedure. Especially, the presence of the UIP pattern on CT (OR, 0.385; 95% CI: 0.172-0.863; p = 0.020) was independently associated with failed diagnosis. Among patients with UIP, "within the lesion" status on EBUS (OR, 25.432; 95% CI: 2.321-278.666; p = 0.008) was shown to be a factor contributing to a successful diagnosis. Overall, there were no significant differences in complication rates among the 3 study groups. CONCLUSION: RP-EBUS-TBLB can be performed safely with an acceptable diagnostic yield, even in patients with IPF.

Taste-based gender discrimination in South Korea.

Among the countries of the Organization for Economic Co-operation and Development, South Korea shows the worst female earnings disadvantage. Women's career disruption associated with marriage and childbearing is said to be the primary factor behind the huge female disadvantage in Korea. Recent studies, however, demonstrated that substantial female disadvantage appears prior to women's career disruption, even net of human capital covariates. In this study, we examine whether taste-based gender discrimination is a source of female earnings disadvantage. We use sex ratios of births across regions during the 1990s as a proxy of prejudice against women in current labor markets. Our empirical results show that female earnings disadvantages among 2009-2017 college graduates are larger in the regions where sex ratios of 1990-1999 newborns were higher. Our results are robust to the control of an extensive set of human capital variables, including concrete college names, detailed fields of study, high school types, and more. Depending on models, one-fourth to one-third of female earnings disadvantage is attributable to prejudice against women. Implications of these findings are discussed.

How Do We Start Palliative Care for Patients With End-Stage Liver Disease?

Patients with end-stage liver disease undergo repetitive patterns of recovery and deterioration and are burdened with uncertainty. Although quality of life is low in patients with end-stage liver disease and their family members, few studies have been conducted to identify what palliative care should be provided for them. This integrative review aimed to explore palliative care for patients with end-stage liver disease, focusing on the components and outcome measurements for further research. After searching for studies on palliative care for end-stage liver disease published between 1995 and 2017, 12 studies that met the inclusion criteria were analyzed. The common components of palliative care for patients with liver disease were: (a) an interdisciplinary approach, (b) early palliative care, (c) discussion goals of care with patient and family members, (d) symptom management, and (e) psychosocial support. It was reported that patients who were provided palliative care had improved itching, well-being, appetite, anxiety, fatigue, and depression, increased the number of do-not-resuscitate orders, palliative care consultations, and decreased length of stay. These findings could guide the development of palliative care for end-stage liver disease patients.

Design of a Sensitive Balloon Sensor for Safe Human-Robot Interaction.

As the safety of a human body is the main priority while interacting with robots, the field of tactile sensors has expanded for acquiring tactile information and ensuring safe human-robot interaction (HRI). Existing lightweight and thin tactile sensors exhibit high performance in detecting their surroundings. However, unexpected collisions caused by malfunctions or sudden external collisions can still cause injuries to rigid robots with thin tactile sensors. In this study, we present a sensitive balloon sensor for contact sensing and alleviating physical collisions over a large area of rigid robots. The balloon sensor is a pressure sensor composed of an inflatable body of low-density polyethylene (LDPE), and a highly sensitive and flexible strain sensor laminated onto it. The mechanical crack-based strain sensor with high sensitivity enables the detection of extremely small changes in the strain of the balloon. Adjusting the geometric parameters of the balloon allows for a large and easily customizable sensing area. The weight of the balloon sensor was approximately 2 g. The sensor is employed with a servo motor and detects a finger or a sheet of rolled paper gently touching it, without being damaged.

Use of an Insulation-Tipped Knife during Rigid Bronchoscopic Treatment of Benign Tracheobronchial Stenosis.

Background and Objectives: Tracheal or bronchial tears are potential complications of rigid bronchoscopy. This study aimed to investigate the acute complications and outcomes of using an insulation-tipped (IT) knife in combination with rigid bronchoscopic dilatation for treating benign tracheobronchial stenosis. Materials and Methods: We conducted a chart review of patients with benign tracheobronchial stenosis who were treated with rigid bronchoscopy and an IT knife at two referral centers. Treatment success was defined as a clinically stable state without worsening symptoms after 3 months of treatment. Results: Of the 23 patients with benign tracheobronchial stenosis, 15 had tracheal stenosis and 6 had main bronchial stenosis. Among them, three cases were of simple stenosis (13%), while the others were of complex stenosis (87%). The overall treatment success rate was 87.0%. Pneumomediastinum and subcutaneous emphysema occurred due to bronchial laceration in two cases of distal left main bronchial stenosis (8.7%), and no other significant acute complications developed. Silicone stents were inserted in 20 patients, and successful stent removal was possible in 11 patients (55.0%). Six of the seven stents inserted in patients with post-intubation tracheal stenosis were removed successfully (85.7%). However, most of the patients with post-tracheostomy tracheal stenosis required persistent stenting (80%). Pulmonary function was significantly increased after treatment, and the mean increase in the forced expiratory volume in 1 s was 391 ± 171 mL (160-700 mL). Conclusion: The use of an IT knife can be suggested as an effective and safe modality for rigid bronchoscopic treatment of benign tracheobronchial stenosis.

Bacillus subtilis spore vaccines displaying protective antigen induce functional antibodies and protective potency.

BACKGROUND: Bacillus anthracis is the causative agent of anthrax, a disease of both humans and various animal species, and can be used as a bioterror agent. Effective vaccines are available, but those could benefit from improvements, including increasing the immunity duration, reducing the shot frequency and adverse reactions. In addition, more sophisticated antigen delivery and potentiation systems are urgently required. The protective antigen (PA), one of three major virulence factors associated with anthrax was displayed on the surface of Bacillus subtilis spores, which is a vaccine production host and delivery vector with several advantages such as a low production cost, straightforward administration as it is safe for human consumption and the particulate adjuvanticity. Mice were immunized orally (PO), intranasally (IN), sublingually (SL) or intraperitoneally (IP) with the PA displaying probiotic spore vaccine. Clinical observation, serological analysis and challenge experiment were conducted to investigate the safety and efficacy of the vaccine. RESULTS: A/J mice immunized with the PA spore vaccine via PO, IN, SL, and IP were observed to have increased levels of active antibody titer, isotype profiles and toxin neutralizing antibody in sera, and IgA in saliva. The immunized mice were demonstrated to raise protective immunity against the challenge with lethal B. anthracis spores. CONCLUSIONS: In this study, we developed a B. subtilis spore vaccine that displays the PA on its surface and showed that the PA-displaying spore vaccine was able to confer active immunity to a murine model based on the results of antibody isotype titration, mucosal antibody identification, and a lethal challenge experiment.

Intravenous aspirin challenge as a diagnosis of nonsteroidal anti-inflammatory drugs hypersensitivity.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are a major cause of drug-induced hypersensitivity, called "NSAID hypersensitivity". A confirmative diagnosis is necessary for ensuring drug safety and finding alternative drugs. No reliable test other than direct challenge is diagnostic. An intravenous (IV) aspirin challenge has rarely been tried. OBJECTIVE: To assess the safety and efficacy of the aspirin IV provocation test. METHODS: A retrospective and descriptive study in a hospital. Clinical data were reviewed in patients who had aspirin IV provocation test with lysine aspirin. RESULTS: In 71 patients suspected of having NSAID hypersensitivity, aspirin IV provocation test was performed. Most provocations were performed on the same day. Forty-three (60.6%) showed a positive response to the challenge. The positive reactions were rescued mostly by antihistamines or glucocorticoids and rarely with bronchodilators and epinephrine. Three patients who showed a negative response to the aspirin challenge were shown to have single-NSAID hypersensitivity. For confirmation of NSAID hypersensitivity in these patients, the sensitivity of the IV aspirin provocation test was 93.5%. CONCLUSIONS: Aspirin IV provocation test with lysine aspirin on the same day is safe and efficacious for diagnosing NSAID hypersensitivity.

Broken promise of college? New educational sorting mechanisms for intergenerational association in the 21st century.

Previous studies have shown that intergenerational socioeconomic association becomes weaker as children's education level increases and is negligible among college graduates. A college degree is known as the great equalizer for intergenerational socioeconomic mobility. Recent studies, however, reported that the strong intergenerational association reemerges among advanced degree holders although it stays weak among BA-only holders. Despite the substantial theoretical importance and policy implications, the mechanisms behind the reemergence of the intergenerational association at the post-baccalaureate level have been less studied. In this paper, we examine the association between parents' education and children's earnings using the 2010, 2013, 2015, and 2017 National Survey of College Graduates data. Our results show that the strong intergenerational socioeconomic immobility among advanced degree holders is fully attributable to three educational sorting mechanisms: children from high-SES families (1) obtain expensive and financially rewarding advanced degrees, (2) attend selective institutions and major in hyper-lucrative fields of study such as law and medicine in graduate school, and (3) complete their education at a younger age and enjoy income growth over more years in the labor market. Implications of these findings are discussed.

Educational Variations in Cohort Trends in the Black-White Earnings Gap Among Men: Evidence From Administrative Earnings Data.

Despite efforts to improve the labor market situation of African Americans, the racial earnings gap has endured in the United States. Most prior studies on racial inequality have considered its cross-sectional or period patterns. This study adopts a demographic perspective to examine the evolution of earnings trajectories among white and black men across cohorts in the United States. Using more than 40 years of longitudinal earnings records from the U.S. Social Security Administration matched to the Survey of Income and Program Participation, our analyses reveal that the cohort trends in the racial earnings gap follow quite different patterns by education. Race continues to be a salient dimension of economic inequality over the life course and across cohorts, particularly at the top and the bottom of the educational distribution. Although the narrowing of the racial gap among high school graduates is in itself a positive development, it unfortunately derives primarily from the deteriorating economic position for whites without a college degree rather than an improvement in economic standing of their black counterparts.

An additional tilted-scan-based CT metal-artifact-reduction method for radiation therapy planning.

PURPOSE: As computed tomography (CT) imaging is the most commonly used modality for treatment planning in radiation therapy, metal artifacts in the planning CT images may complicate the target delineation and reduce the dose calculation accuracy. Although current CT scanners do provide certain correction steps, it is a common understanding that there is not a universal solution yet to the metal artifact reduction (MAR) in general. Particularly noting the importance of MAR for radiation treatment planning, we propose a novel MAR method in this work that recruits an additional tilted CT scan and synthesizes nearly metal-artifact-free CT images. METHODS: The proposed method is based on the facts that the most pronounced metal artifacts in CT images show up along the x-ray beam direction traversing multiple metallic objects and that a tilted CT scan can provide complementary information free of such metal artifacts in the earlier scan. Although the tilted CT scan would contain its own metal artifacts in the images, the artifacts may manifest in a different fashion leaving a chance to concatenate the two CT images with the metal artifacts much suppressed. We developed an image processing technique that uses the structural similarity (SSIM) for suppressing the metal artifacts. On top of the additional scan, we proposed to use an existing MAR method for each scan if necessary to further suppress the metal artifacts. RESULTS: The proposed method was validated by a simulation study using the pelvic region of an XCAT numerical phantom and also by an experimental study using the head part of the Rando phantom. The proposed method was found to effectively reduce the metal artifacts. Quantitative analyses revealed that the proposed method reduced the mean absolute percentages of the error by up to 86% and 89% in the simulation and experimental studies, respectively. CONCLUSIONS: It was confirmed that the proposed method, using complementary information acquired from an additional tilted CT scan, can provide nearly metal-artifact-free images for the treatment planning.

Nurses' perceived barriers and educational needs for early mobilisation of critical ill patients.

BACKGROUND: Early mobilisation (EM) of critically ill patients is an evidence-based intervention designed to improve treatment outcomes and enhance the quality of life after intensive care. However, several barriers exist to its establishment in clinical practice. Thus, the objective of the present study was to identify barriers perceived by critical care nurses, corresponding educational needs, and provide useful information for program implementation in Korea. METHODS: A cross-sectional study was conducted from April to June 2017 using a structured, self-administered questionnaire that was completed by 151 critical care nurses from three tertiary hospitals and four secondary hospitals located in Seoul. The survey was designed to rate experiences with EM, identify educational experiences, and measure perceived barriers regarding attitudes, knowledge, behaviours, and educational needs. Data were analysed using descriptive statistics, t-tests, and analyses of variance. RESULTS: The mean number of perceived barriers was 3.13 ± 0.38 out of 5 on a Likert scale. Attitude-related barriers (3.25 ± 0.49) were higher than behaviour-related (3.21 ± 0.44) and knowledge-related (2.94 ± 0.59) barriers. The top five barrier items were high workload, patients' inability to exercise, lack of time, inappropriate nurse/patient ratio, and absence of relevant education. Educational needs for early mobilisation were rated 3.74 ± 0.78 out of 5. Educational items were prioritised as identifying potential problems in EM and possible solutions, related protocols and guidelines, and procedures for special conditions. CONCLUSIONS: The present study revealed that critical care nurses in Korea perceive various barriers to successfully implementing evidence-based EM interventions for critically ill patients, as well as the educational needs necessary to overcome such challenges. Accordingly, an educational program should be developed based on the educational needs revealed in the present study. In parallel, organisational efforts should also be made to meet environmental conditions.

Urinary desmosine is associated with emphysema severity and frequent exacerbation in patients with COPD.

BACKGROUND AND OBJECTIVE: Matrix degradation is a key feature of chronic obstructive pulmonary disease (COPD). Desmosine and isodesmosine (desmosines) are excreted in urine following matrix degradation. The main purpose of this study was to investigate the association between computed tomography (CT) emphysema indices and urinary desmosines in patients with COPD. METHODS: A total of 152 subjects were selected from the Korean Obstructive Lung Disease cohort. Their urine samples were assayed for desmosines using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. The cohort was divided into emphysema-dominant (n = 80) and non-emphysema dominant- (n = 72) groups according to the CT emphysema index. RESULTS: The level of urinary desmosines was significantly higher in the emphysema-dominant group. Significant differences were also observed between the two groups for body mass index and lung function. Multivariate analysis indicated that a high level of urinary desmosines was a significant independent predictor of emphysema (relative risk: 2.6; 95% CI: 1.11-6.09; P = 0.028). The percentage of frequent exacerbators was significantly higher in the high urinary desmosine group in the first year of follow-up (P = 0.041). The mean number of exacerbations was higher in the high urinary desmosine group, although this difference was not statistically significant (P = 0.067). The changes in emphysema index did not differ between the two urinary desmosine groups over 3 years of follow-up. CONCLUSION: This study indicates that the level of urinary desmosines measured by LC-MS/MS methods is associated with the CT emphysema index. Urinary desmosine can be a useful predictor in identifying frequent exacerbators.

Construction of Bacillus thuringiensis Simulant Strains Suitable for Environmental Release.

For a surrogate bacterium to be used in outdoor studies, it is important to consider environmental and human safety and ease of detection. Recently, Bacillus thuringiensis, a popular bioinsecticide bacterium, has been gaining attention as a surrogate bacterium for use in biodefense. In this study, we constructed simulant strains of B. thuringiensis with enhanced characteristics for environmental studies. Through transposon mutagenesis, pigment genes were inserted into the chromosome, producing yellow-colored colonies for easy detection. To prevent persistence of spores in the environment, a genetic circuit was designed to produce a spore without sporulation capability. Two loxP sites were inserted, one on each side of the spo0A gene, which encodes a sporulation master regulator, and a sporulation-dependent Cre expression cassette was inserted into the chromosome. This genetic circuit successfully deleted spo0A during sporulation, producing spores that lacked the spo0A gene. In addition, two major α/ß-type small acid-soluble spore protein (SASP) genes, predicted by synteny analysis, were deleted. The spores of the mutant strain showed increased UV-C sensitivity and quickly lost viability when tested in a solar simulator. When the spores of the mutant strain were administered to the lungs of BALB/c mice, cells were quickly removed from the body, suggesting enhanced in vivo safety. All strains constructed in this study contain no antibiotic resistance markers and all heterologous genes were inserted into the chromosome, which are useful features for simulants to be released into the environment.IMPORTANCEB. thuringiensis has recently been receiving increasing attention as a good spore simulant in biodefense research. However, few studies were done to properly address many important features of B. thuringiensis as a simulant in environmental studies. Since spores can persist in the environment for years after release, environmental contamination is a big problem, especially when genetically engineered strains are used. To solve these problems, we report here the development of B. thuringiensis simulant strains that are capable of forming yellow colonies for easy detection, incapable of forming spores more than once due to a genetic circuit, and lacking in two major SASP genes. The genetic circuit to produce a spore without sporulation capability, together with the deletion of SASP genes, ensures the environmental and human safety of the simulant strains developed in this study. All of these features will allow wider use of B. thuringiensis as a simulant for Bacillus anthracis in environmental release studies.