Intravesicular Solute Delivery and Surface Area Regulation in Giant Unilamellar Vesicles Driven by Cycles of Osmotic Stresses.

Phospholipid bilayers are dynamic cellular components that undergo constant changes in their topology, facilitating a broad diversity of physiological functions including endo- and exocytosis, cell division, and intracellular trafficking. These shape transformations consume energy, supplied invariably by the activity of proteins. Here, we show that cycles of oppositely directed osmotic stresses─unassisted by any protein activity─can induce well-defined remodeling of giant unilamellar vesicles, minimally recapitulating the phenomenologies of surface area homeostasis and macropinocytosis. We find that a stress cycle consisting of deflationary hypertonic stress followed by an inflationary hypotonic one prompts an elaborate sequence of membrane shape changes ultimately transporting molecular cargo from the outside into the intravesicular milieu. The initial osmotic deflation produces microscopic spherical invaginations. During the subsequent inflation, the first subpopulation contributes area to the swelling membrane, thereby providing a means for surface area regulation and tensional homeostasis. The second subpopulation vesiculates into the lumens of the mother vesicles, producing pinocytic vesicles. Remarkably, the gradients of solute concentrations between the GUV and the daughter pinocytic vesicles create cascades of water current, inducing pulsatory transient poration that enable solute exchange between the buds and the GUV interior. This results in an efficient water-flux-mediated delivery of molecular cargo across the membrane boundary. Our findings suggest a primitive physical mechanism for communication and transport across protocellular compartments driven only by osmotic stresses. They also suggest plausible physical routes for intravesicular, and possibly intracellular, delivery of ions, solutes, and molecular cargo stimulated simply by cycles of osmotic currents of water.

Hospitalized acute exacerbation in chronic obstructive pulmonary disease - impact on long-term renal outcomes.

INTRODUCTION: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a common and preventable event in patients with chronic obstructive pulmonary disease (COPD). Data regarding the impact of AECOPD on short- and long-term renal outcomes are lacking. METHODS: We included all COPD patients who were followed at Queen Mary Hospital (QMH) in year 2015 and reviewed their clinical/renal outcomes in subsequent five years. Relationships between AECOPD and adverse renal outcomes were evaluated. RESULTS: 371 COPD patients were included. 169 patients had hospitalized AECOPD in past one year (HAE group) while 202 patients did not (non-HAE group). 285 patients (76.8%) had renal progression/death and 102 (27.5%) patients developed acute kidney injury (AKI). HAE group showed a more rapid eGFR decline than non-HAE group (-4.64 mL/min/1.73m2/year vs. -2.40 mL/min/1.73m2/year, p = 0.025). HAE group had significantly higher risk for renal progression/death at 5 years [adjusted OR (aOR) 2.380 (95% CI = 1.144-4.954), p = 0.020]. The frequency of hospitalized AECOPD in past 3 years, any AECOPD in past 3 years, hospitalized AECOPD in past 3 years were also predictive of renal progression/death at 5 years [aOR were 1.176 (95% CI = 1.038- 1.331), 2.998 (95% CI = 1.438-6.250) and 2.887 (95% CI = 1.409-5.917) respectively; p = 0.011, 0.003 and 0.004]. HAE group also showed significantly higher risk of AKI [adjusted HR (aHR) 2.430; 95% CI = 1.306-4.519, p = 0.005]. CONCLUSIONS: AECOPD, in particular HAE, was associated with increased risk of renal progression/death and AKI. Prevention of AECOPD, especially HAE, may potentially improve short- and long-term renal outcomes in COPD patients.

Severe bronchiectasis is associated with increased carotid intima-media thickness.

BACKGROUND: Although bronchiectasis has been shown to be associated with cardiovascular disease, there is limited evidence of an association with subclinical atherosclerosis, especially carotid intima-media thickness (CIMT). METHODS: This prospective study compared CIMT among patients with and without bronchiectasis, and among bronchiectatic patients classified according to disease severity using the FACED score. The study was carried out at a major regional hospital and tertiary respiratory referral centre in Hong Kong. RESULTS: Total 155 Chinese patients with non-cystic fibrosis (CF) bronchiectasis and 512 controls were recruited. The mean CIMT was 0.58 ± 0.10 mm, 0.63 ± 0.11 mm and 0.66 ± 0.08 mm respectively among controls, patients with mild-to-moderate bronchiectasis and patients with severe bronchiectasis. There was no statistically significant difference in CIMT between patients with mild-to-moderate bronchiectasis and controls. Multivariate linear regression revealed that CIMT was significantly increased in patients with severe bronchiectasis relative to controls. The same phenomenon was observed among patients without a history of cardiovascular disease or cardiovascular risk factors. CONCLUSIONS: CIMT was significantly increased in patients with severe bronchiectasis compared with controls without bronchiectasis, but not among patients with mild-to-moderate bronchiectasis, which suggested the subclinical atherosclerosis to be more prevalent among patients with severe bronchiectasis.

Increased exacerbations of bronchiectasis following recovery from mild COVID-19 in patients with non-cystic fibrosis bronchiectasis.

BACKGROUND AND OBJECTIVE: Respiratory viral infection is a common trigger of bronchiectasis exacerbation. Knowledge of the intermediate to long-term effect of COVID-19 on bronchiectasis is poor. METHODS: A retrospective cohort study of patient records was conducted to assess the frequency of bronchiectasis exacerbation following recovery from mild-to-moderate COVID-19. The exacerbation frequency at baseline, using 2019 and 2019-2021 data, was compared with that during the 1 year following recovery. RESULTS: A total of 234 adult patient records who had a confirmed diagnosis of bronchiectasis were identified, of whom 52 (22.2%) were classified as the COVID-19 group. Patients with COVID-19 had significantly more frequent annual exacerbations of bronchiectasis (total exacerbations and hospitalizations). Compared with 2019-2021 data, the total exacerbation frequency decreased by 0.1 ± 0.51 per year among non-COVID-19 patients but increased by 0.68 ± 1.09 per year among the COVID-19 group (p < 0.001). Compared with 2019 only data, exacerbation frequency decreased by 0.14 ± 0.79 per year among non-COVID-19 patients but increased by 0.76 ± 1.17 per year in the COVID-19 group, p < 0.001. The annual frequency of hospitalization for bronchiectasis increased by 0.01 ± 0.32 per year among non-COVID-19 patients and increased by 0.39 ± 1.06 per year in the COVID-19 group (p < 0.001) compared with 2019 to 2021 data. When compared with only 2019 data, it remained unchanged at 0 ± 0.43 per year among non-COVID-19 patients but increased to 0.38 ± 1.12 per year among COVID-19 patients (p < 0.001). CONCLUSION: Mild-to-moderate COVID-19 was associated with an increase in frequency of bronchiectasis exacerbation and frequency of hospitalizations following recovery.

High-sensitivity C-reactive protein level in stable-state bronchiectasis predicts exacerbation risk.

BACKGROUND: Elevation of systemic inflammatory markers were found to correlate with increased disease extent, reduced lung function and higher risk of future severe exacerbations in patients with bronchiectasis. Although a significant correlation of circulating hs-CRP levels with HRCT scores and resting oxygen saturation in patients with stable-state non-cystic fibrosis (CF) bronchiectasis was suggested, there is little data on the relationship between hs-CRP and the prognosis of bronchiectasis and a lack of data on the role of hs-CRP in predicting bronchiectasis exacerbation. METHODS: A prospective study was conducted on Chinese patients with non- CF bronchiectasis from 1st October to 31st December 2021. Baseline serum hs-CRP were obtained at stable-state. The follow-up period lasted for one year. Co-primary endpoints were the development of any bronchiectasis exacerbation and hospitalized bronchiectasis exacerbation. RESULTS: Totally 123 patients were included. Higher hs-CRP was associated with increased risk to develop any bronchiectasis exacerbation, adjusted odds ratio (aOR) of 2.254 (95% CI = 1.040-4.885, p = 0.039), and borderline significantly increased hospitalized bronchiectasis exacerbation with aOR of 1.985 (95% CI = 0.922-4.277, p = 0.080). CONCLUSION: Baseline serum hs-CRP level at stable-state can predict risk of bronchiectasis exacerbation, which is reflecting chronic low-grade inflammation in bronchiectasis.

Worsening of asthma control after recovery from mild to moderate COVID-19 in patients from Hong Kong.

BACKGROUND: While there are postulations that asthma is potentially associated with severe coronavirus disease 2019 (COVID-19), there has been conflicting results from studies on the impact mild-to-moderate COVID-19 on asthma control after recovery. METHODS: A case control study on the association between mild-to-moderate COVID-19 and asthma control post infection was conducted. The primary outcome was a reduction in Asthma Control Test (ACT) score by ≥ 3 points post-COVID infection. The secondary outcomes included the change in ACT score, the proportion of patient with ACT score who dropped to ≤ 15 on enrolment visit and the need for escalation of asthma maintenance therapy. RESULTS: Out of the total of 221 adult patients with asthma recruited, 111 had mild-to-moderate COVID-19 within 30 to 270 days prior to study enrolment. The adjusted odds ratio (aOR) for a reduction in ACT score by ≥ 3 points after COVID-19 was 3.105 (95% CI = 1.385-6.959, p = 0.006). The odds of escalation of asthma maintenance therapy by at least 1 Global Initiative for Asthma (GINA) step was 4.733 (95% CI = 1.151-19.467, p = 0.031) and asthma patient are more likely to become uncontrolled after COVID-19 [aOR = 5.509 (95% CI = 1.061-28.600, p = 0.042)]. CONCLUSION: Mild-to-moderate COVID-19 among asthma patients, upon recovery, was associated with worsening of asthma symptom, lower ACT score, a higher need for escalation of asthma maintenance therapy and more uncontrolled asthma.

An Evaluation of Gene-Diet Interaction Statistical Methods and Discovery of rs7175421-Whole Grain Interaction in Lung Cancer.

Dietary factors show different effects on genetically diverse populations. Scientific research uses gene-environment interaction models to study the effects of dietary factors on genetically diverse populations for lung cancer risk. However, previous study designs have not investigated the degree of type I error inflation and, in some instances, have not corrected for multiple testing. Using a motivating investigation of diet-gene interaction and lung cancer risk, we propose a training and testing strategy and perform real-world simulations to select the appropriate statistical methods to reduce false-positive discoveries. The simulation results show that the unconstrained maximum likelihood (UML) method controls the type I error better than the constrained maximum likelihood (CML). The empirical Bayesian (EB) method can compete with the UML method in achieving statistical power and controlling type I error. We observed a significant interaction between SNP rs7175421 with dietary whole grain in lung cancer prevention, with an effect size (standard error) of -0.312 (0.112) for EB estimate. SNP rs7175421 may interact with dietary whole grains in modulating lung cancer risk. Evaluating statistical methods for gene-diet interaction analysis can help balance the statistical power and type I error.

Prediction model on disease recurrence for low risk resected stage I lung adenocarcinoma.

BACKGROUND AND OBJECTIVE: Although stage I non-small cell lung carcinoma (NSCLC) typically carries a good prognosis following complete resection, early disease recurrence can occur. An accurate survival prediction model would help refine a follow-up strategy and personalize future adjuvant therapy. We developed a post-operative prediction model based on readily available clinical information for patients with stage I adenocarcinoma. METHODS: We retrospectively studied the disease-free survival (DFS) of 408 patients with pathologically confirmed low-risk stage I adenocarcinoma of lung who underwent curative resection from 2013 to 2017. A tree-based method was employed to partition the cohort into subgroups with distinct DFS outcome and stepwise risk ratio. These covariates were included in multivariate analysis to build a scoring system to predict disease recurrence. The model was subsequently validated using a 2011-2012 cohort. RESULTS: Non-smoker status, stage IA disease, epidermal-growth factor receptor mutants and female gender were associated with better DFS. Multivariate analysis identified smoking status, disease stage and gender as factors necessary for the scoring system and yielded 3 distinct risk groups for DFS [99.4 (95% CI 78.3-125.3), 62.9 (95% CI 48.2-82.0), 33.7 (95% CI 24.6-46.1) months, p < 0.005]. External validation yielded an area under the curve by receiver operating characteristic analysis of 0.863 (95% CI 0.755-0.972). CONCLUSION: The model could categorize post-operative patients using readily available clinical information, and may help personalize a follow-up strategy and future adjuvant therapy.

Does the clopidogrel CYP2C19 genotype assay predict postprocedure stenosis in cerebral aneurysms treated with a flow diverter?

OBJECTIVE: Flow diverters have emerged as a popular modality for treating cerebral aneurysms but require dual antiplatelet therapy (DAPT) after placement. Clopidogrel is a common choice but is a prodrug that some patients may not convert into an active metabolite. The CYP2C19 genotype assay is used to predict activation speed; however, limited data exist showcasing whether this genotype accurately predicts postprocedure complications after flow diversion treatment of cerebral aneurysms. Therefore, the authors sought to characterize whether CYP2C19 genotype correlated with the development of postprocedure intimal hyperplasia (stenosis) after flow diverter placement. METHODS: Medical records were reviewed for patients who underwent flow diverter treatment of cerebral aneurysm at a single academic institution between January 1, 2012, and May 31, 2020. Patient demographics and comorbidities were reviewed alongside CYP2C19 genotype assay, DAPT regimen, and postprocedure angiogram data. Stenosis was defined based on review of angiogram data by two independent physicians. RESULTS: In this review of 120 unique cerebral aneurysms, 102 received DAPT with clopidogrel and 18 received DAPT with an alternative agent. Stenosis was present on 3-month follow-up angiogram for 35/102 (34.3%) aneurysms receiving DAPT with clopidogrel and in 11/18 (61.1%) aneurysms receiving an alternative DAPT regimen (p = 0.031). The CYP2C19 genotype did not correlate with postprocedure stenosis (p = 0.35). CONCLUSIONS: Clopidogrel was a significantly more effective DAPT agent for preventing stenosis when compared to nonclopidogrel DAPT regimens. The clopidogrel CYP2C19 genotype did not predict postprocedure stenosis in this cohort of 120 cerebral aneurysms treated with a flow diverter.

Surfactant-Mediated Solubilization of Myelin Figures: A Multistep Morphological Cascade.

Lamellar mesophases of insoluble lipids are readily solubilized by the micellar mesophases of soluble surfactants. This simple process underscores a broad array of biochemical methodologies, including purification, reconstitution, and crystallization of membrane proteins, as well as the isolation of detergent-resistant membrane fractions. Although much is now known about the thermodynamic driving forces of membrane solubilization, the kinetic pathways by which the surfactant alters vesicular mesophases are only beginning to be appreciated. Little is known about how these interactions affect the solubilization of more complex, multilamellar mesophases. Here, we investigate how a common zwitterionic detergent affects the solubilization of a smectic, multilamellar, cylindrical mesophase of lipids, called the myelin figure. Our results reveal that myelin solubilization occurs in a multistep manner, producing a well-defined sequence of morphologically distinct intermediates en route to complete solubilization. The kinetic processes producing these intermediates include (1) coiling, which encompasses the formation, propagation, and tightening of extended helices; (2) thinning, which reflects the unbinding of lamellae in the smectic stacks; and (3) detachment or retraction, which either dissociates the myelinic protrusion from the source lipid mass or returns the myelinic protrusion to the source lipid mass─all in transit toward complete solubilization. These occasionally overlapping steps are most pronounced in single-lipid component myelins, while compositionally graded multicomponent myelins inhibit the coiling step and detach more frequently. Taken together, the appearance of these intermediates during the solubilization of myelins suggests a complex free-energy landscape characterizing myelin solubilization populated by metastable, morphological intermediates correlated with locally minimized changes in energy dependent upon the mesophase's composition. This then predicts the accessibility of structurally distinct, kinetic intermediates─such as loose and tight coiled helices, peeled myelins, retracted tubes, and detached protrusions─before reaching the stable ground state corresponding to a dissolved suspension of mixed surfactant-lipid micelles.