b Effects of Lung Injury and Abdominal Insufflation on Respiratory Mechanics and Lung Volume During Time-Controlled Adaptive Ventilation By rc.rcjournal.com Published On :: 2024-10-25T05:44:12-07:00 BACKGROUD:Lung volume measurements are important for monitoring functional aeration and recruitment and may help guide adjustments in ventilator settings. The expiratory phase of airway pressure release ventilation (APRV) may provide physiologic information about lung volume based on the expiratory flow-time slope, angle, and time to approach a no-flow state (expiratory time [TE]). We hypothesized that expiratory flow would correlate with estimated lung volume (ELV) as measured using a modified nitrogen washout/washin technique in a large-animal lung injury model.METHODS:Eight pigs (35.2 ± 1.0 kg) were mechanically ventilated using an Engström Carescape R860 on the APRV mode. All settings were held constant except the expiratory duration, which was adjusted based on the expiratory flow curve. Abdominal pressure was increased to 15 mm Hg in normal and injured lungs to replicate a combination of pulmonary and extrapulmonary lung injury. ELV was estimated using the Carescape FRC INview tool. The expiratory flow-time slope and TE were measured from the expiratory flow profile.RESULTS:Lung elastance increased with induced lung injury from 29.3 ± 7.3 cm H2O/L to 39.9 ± 15.1cm H2O/L, and chest wall elastance increased with increasing intra-abdominal pressures (IAPs) from 15.3 ± 4.1 cm H2O/L to 25.7 ± 10.0 cm H2O/L in the normal lung and 15.8 ± 6.0 cm H2O/L to 33.0 ± 6.2 cm H2O/L in the injured lung (P = .39). ELV decreased from 1.90 ± 0.83 L in the injured lung to 0.67 ± 0.10 L by increasing IAP to 15 mm Hg. This had a significant correlation with a TE decrease from 2.3 ± 0.8 s to 1.0 ± 0.1 s in the injured group with increasing insufflation pressures (ρ = 0.95) and with the expiratory flow-time slope, which increased from 0.29 ± 0.06 L/s2 to 0.63 ± 0.05 L/s2 (ρ = 0.78).CONCLUSIONS:Changes in ELV over time, and the TE and flow-time slope, could be used to demonstrate evolving lung injury during APRV. Using the slope to infer changes in functional lung volume represents a unique, reproducible, real-time, bedside technique that does not interrupt ventilation and may be used for clinical interpretation. Full Article
b Effect of Fasting Prior to Extubation on Prevalence of Empty Stomach in Enterally Fed and Mechanically Ventilated Patients By rc.rcjournal.com Published On :: 2024-10-25T05:44:12-07:00 BACKGROUND:Practice on fasting prior to extubation in critically ill patients is variable. Efficacy of fasting in reducing gastric volume has not been well established. The primary objective of this study was to assess the effect of 4 h of fasting on prevalence of empty stomach using gastric ultrasonography in critically ill subjects who are fasted for extubation. The secondary objectives were to evaluate the change in gastric volumes during 4 h of fasting and to determine factors associated with empty stomach after fasting.METHODS:This was a single-center, prospective, observational study on adult ICU subjects who were enterally fed for at least 6 h continuously and mechanically ventilated. Gastric ultrasound was performed immediately prior to commencement of fasting, after 4 h of fasting, and after nasogastric (NG) aspiration after 4 h of fasting. An empty stomach was defined as a gastric volume ≤ 1.5 mL/kg.RESULTS:Forty subjects were recruited, and 38 (95%) had images suitable for analysis. The prevalence of empty stomach increased after 4 h of fasting (25 [65.8%] vs 31 [81.6%], P = .041) and after 4 h of fasting with NG aspiration (25 [65.8%] vs 34 [89.5%], P = .008). There was a significant difference in median (interquartile range) gastric volume per body weight between before fasting and 4 h after fasting (1.0 [0.5–1.8] mL/kg vs 0.4 [0.2–1.0] mL/kg, P < .001). No patient factors were associated with higher prevalence of empty stomach after 4 h of fasting.CONCLUSIONS:Most mechanically ventilated subjects had empty stomachs prior to fasting for extubation. Fasting for 4 h further increased the prevalence of empty stomach at extubation to > 80%. Full Article
b Feasibility of Delivering 5-Day Normobaric Hypoxia Breathing in a Hospital Setting By rc.rcjournal.com Published On :: 2024-10-25T05:44:12-07:00 BACKGROUND:Beneficial effects of breathing at FIO2 < 0.21 on disease outcomes have been reported in previous preclinical and clinical studies. However, the safety and intra-hospital feasibility of breathing hypoxic gas for 5 d have not been established. In this study, we examined the physiologic effects of breathing a gas mixture with FIO2 as low as 0.11 in 5 healthy volunteers.METHODS:All 5 subjects completed the study, spending 5 consecutive days in a hypoxic tent, where the ambient oxygen level was lowered in a stepwise manner over 5 d, from FIO2 of 0.16 on the first day to FIO2 of 0.11 on the fifth day of the study. All the subjects returned to an environment at room air on the sixth day. The subjects' SpO2, heart rate, and breathing frequency were continuously recorded, along with daily blood sampling, neurologic evaluations, transthoracic echocardiography, and mental status assessments.RESULTS:Breathing hypoxia concentration dependently caused profound physiologic changes, including decreased SpO2 and increased heart rate. At FIO2 of 0.14, the mean SpO2 was 92%; at FIO2 of 0.13, the mean SpO2 was 93%; at FIO2 of 0.12, the mean SpO2 was 88%; at FIO2 of 0.11, the mean SpO2 was 85%; and, finally, at an FIO2 of 0.21, the mean SpO2 was 98%. These changes were accompanied by increased erythropoietin levels and reticulocyte counts in blood. All 5 subjects concluded the study with no adverse events. No subjects exhibited signs of mental status changes or pulmonary hypertension.CONCLUSIONS:Results of the current physiologic study suggests that, within a hospital setting, delivering FIO2 as low as 0.11 is feasible and safe in healthy subjects, and provides the foundation for future studies in which therapeutic effects of hypoxia breathing are tested. Full Article
b Invasive Mechanical Ventilation and Risk of Hospital-Acquired Venous Thromboembolism By rc.rcjournal.com Published On :: 2024-10-25T05:44:12-07:00 BACKGROUND:This study sought to estimate the overall cumulative incidence and odds of Hospital-acquired venous thromboembolism (VTE) among critically ill children with and without exposure to invasive ventilation. In doing so, we also aimed to describe the temporal relationship between invasive ventilation and hospital-acquired VTE development.METHODS:We performed a retrospective cohort study using Virtual Pediatric Systems (VPS) data from 142 North American pediatric ICUs among children < 18 y of age from January 1, 2016–December 31, 2022. After exclusion criteria were applied, cohorts were identified by presence of invasive ventilation exposure. The primary outcome was cumulative incidence of hospital-acquired VTE, defined as limb/neck deep venous thrombosis or pulmonary embolism. Multivariate logistic regression was used to determine whether invasive ventilation was an independent risk factor for hospital-acquired VTE development.RESULTS:Of 691,118 children studied, 86,922 (12.4%) underwent invasive ventilation. The cumulative incidence of hospital-acquired VTE for those who received invasive ventilation was 1.9% and 0.12% for those who did not (P < .001). The median time to hospital-acquired VTE after endotracheal intubation was 6 (interquartile range 3–14) d. In multivariate models, invasive ventilation exposure and duration were each independently associated with development of hospital-acquired VTE (adjusted odds ratio 1.64 [95% CI 1.42–1.86], P < .001; and adjusted odds ratio 1.03 [95% CI 1.02–1.03], P < .001, respectively).CONCLUSIONS:In this multi-center retrospective review from the VPS registry, invasive ventilation exposure and duration were independent risk factors for hospital-acquired VTE among critically ill children. Children undergoing invasive ventilation represent an important target population for risk-stratified thromboprophylaxis trials. Full Article
b Rehabilitation Is Associated With Improvements in Post-COVID-19 Sequelae By rc.rcjournal.com Published On :: 2024-10-25T05:44:12-07:00 BACKGROUND:Post–COVID-19 syndrome has affected millions of people, with rehabilitation being at the center of non-pharmacologic care. However, numerous published studies show conflicting results due to, among other factors, considerable variation in subject characteristics. Currently, the effects of age, sex, time of implementation, and prior disease severity on the outcomes of a supervised rehabilitation program after COVID-19 remain unknown.METHODS:This was a non-randomized case-control study. Subjects with post–COVID-19 sequelae were enrolled. Among study participants, those who could attend an 8-week, supervised rehabilitation program composed the intervention group, whereas those who couldn’t the control group. Measurements were collected at baseline and 8 weeks thereafter.RESULTS:Study groups (N = 119) had similar baseline measurements. Participation in rehabilitation (n = 47) was associated with clinically important improvements in the 6-min walk test (6MWT) distance, adjusted (for potential confounders) odds ratio (AOR) 4.56 (95% CI 1.95–10.66); 1-min sit-to-stand test, AOR 4.64 (1.88-11.48); Short Physical Performance Battery, AOR 7.93 (2.82–22.26); health-related quality of life (HRQOL) 5-level EuroQol-5D (Visual Analog Scale), AOR 3.12 (1.37–7.08); Montreal Cognitive Assessment, AOR 6.25 (2.16–18.04); International Physical Activity Questionnaire, AOR 3.63 (1.53–8.59); Fatigue Severity Scale, AOR 4.07 (1.51–10.98); Chalder Fatigue Scale (bimodal score), AOR 3.33 (1.45–7.67); Modified Medical Research Council dyspnea scale (mMRC), AOR 4.43 (1.83–10.74); Post–COVID-19 Functional Scale (PCFS), AOR 3.46 (1.51–7.95); and COPD Assessment Test, AOR 7.40 (2.92–18.75). Time from disease onset was marginally associated only with 6MWT distance, AOR 0.99 (0.99–1.00). Prior hospitalization was associated with clinically important improvements in the mMRC dyspnea scale, AOR 3.50 (1.06–11.51); and PCFS, AOR 3.42 (1.16–10.06). Age, sex, and ICU admission were not associated with the results of any of the aforementioned tests/grading scales.CONCLUSIONS:In this non-randomized, case-control study, post–COVID-19 rehabilitation was associated with improvements in physical function, activity, HRQOL, respiratory symptoms, fatigue, and cognitive impairment. These associations were observed independently of timing of rehabilitation, age, sex, prior hospitalization, and ICU admission. Full Article
b Comparison of Web-Based and On-Site Lung Simulators for Education in Mechanical Ventilation By rc.rcjournal.com Published On :: 2024-10-25T05:44:12-07:00 BACKGROUND:Training in mechanical ventilation is a key goal in critical care fellowship education. Web-based simulators offer a cost-effective and readily available alternative to traditional on-site simulators. However, it is unclear how effective they are as teaching tools. In this study, we evaluated the test scores of fellows who underwent mechanical ventilation training by using a web-based simulator compared with fellows who used an on-site simulator during a mechanical ventilation course.METHODS:This was a nonrandomized controlled trial conducted as part of a mechanical ventilation course that involved 70 first-year critical care fellows. The course was identical except for the simulation technology used. One group of instructors used a traditional on-site simulator, the ASL 5000 Lung Solution (n = 39). The second group was instructed in using a web-based simulator, VentSim (n = 31). Each fellow completed a pre-course test and a post-course test by using a validated, case-based ventilator waveform examination that consisted of 5 questions with a total possible score of 100. The primary outcome was a comparison of the mean scores on the posttest between the 2 groups. The study was designed as a non-inferiority trial with a predetermined margin of 10 points.RESULTS:There was no significant difference in the mean ± SD pretest scores between the web-based and the on-site groups (21.1 ± 12.6 and 26.9 ± 13.6 respectively; P = .11). The mean ± SD posttest scores were 45.6 ± 25.0 for the web-based simulator and 43.4 ± 16.5 for on-site simulator (mean difference 2.2; one-sided 95% CI –7.0 to ∞; Pnon-inferiority = .02 [non-inferiority confirmed]). Changes in mean ± SD scores (posttest – pretest) were 25.9 ± 20.9 for the web-based simulator and 16.5 ± 15.9 for the on-site simulator (mean difference 9.4, one-sided 95% CI 0.9 to ∞; Pnon-inferiority < .001 [non-inferiority confirmed]).CONCLUSIONS:In the education of first-year critical care fellows on mechanical ventilation waveform analysis, a web-based mechanical ventilation simulator was non-inferior to a traditional on-site mechanical ventilation simulator. Full Article
b Intraprofessional Education Experiences in Dentistry: Dental hygienists’ perceptions of collaboration with dentists By jdh.adha.org Published On :: 2024-10-15T09:18:41-07:00 Purpose Health care professionals (HCPs) working collaboratively can improve patient outcomes and also increase their understanding of each other’s professional roles. This descriptive study aimed to explore dental hygienists’ perceptions of collaboration with dentists and intraprofessional educational (IntraPE) experiences.Methods A convenience sampling method was used to assess DHs perceptions of collaboration with dentists using the Interprofessional Collaboration Scale (ICS), a validated scale that measures perceptions of communication, accommodation, and isolation among HCPs. One open-ended question was added to explore IntraPE. Demographics, work characteristics and responses from the ICS were analyzed using frequency, mean, standard deviation, Pearson’s correlation, t-test, ANOVA, and multivariable regression. Responses from the open-ended question were transcribed, organized, and coded. Themes were identified using the Delve Qualitative Analysis Tool.Results Of the 264 participants, the average age was 38.9, and most identified as female (98.9%). Data analysis revealed that DHs had positive perceptions of collaboration with dentists. Significant relationships were found between ICS factor accommodation and the average number of patients treated per day (rs = −0.242, p<0.001), dentists’ age (rs = −.145, p<0.05). Isolation showed a significant negative correlation with the average number of patients treated per day (rs = −0.156, p<0.05). Most reported having no opportunities for IntraPE education experiences with dentists. Five categories of themes were identified from the open-ended question: shared academic setting, clinic dentist, externships, desire for more shared learning, and shared patient experiences.Conclusion Dental hygienists in this study had an overall more positive than negative perception of collaboration with dentists. Dental and dental hygiene programs should focus on intraprofessional education experiences to continue to enhance collaboration. Full Article
b Comparison of Needle Depth Techniques for the Posterior Superior Alveolar Block By jdh.adha.org Published On :: 2024-10-15T09:18:41-07:00 Purpose The posterior superior alveolar (PSA) block injection is one of many techniques used to provide profound anesthesia for invasive dental procedures. This technique has a high success rate but is not without complication risks. The purpose of this study was to determine if pulpal anesthesia of the maxillary second molar could be achieved using a reduced needle depth of 10mm or 5mm compared to the traditional needle depth of 16mm.Methods Sixty participants were asked to participate in three sessions. Each session started with a pre neural response test, followed by one randomized needle depth PSA injection, and ending with a post neural response test. The neural response test consisted of two parts, a cold refrigerant and a dental probe, on the buccal and interproximal surface of the maxillary second molar. After receiving a positive neural response, each participant received a posterior superior alveolar block injection using a short (21mm), 27-gauge dental needle with a randomized needle penetration depth of 16mm, 10mm, or 5mm. A post neural response test consisting of the same two parts as the pre-test was conducted on the maxillary second molar to evaluate for profound anesthesia.Results Positive neural responses were obtained from 100% of the participants (n=167) during the pre-tests. Study results demonstrated an 85% success rate at the traditional 16mm needle depth and a 93% and 92% success rates for the reduced needle depths of 10mm and 5mm, respectively. Pulpal anesthesia of the maxillary second molar had been achieved at all three needle depths with no statistically significant difference in the rate of success. Furthermore, there were no adverse events observed.Conclusion The reduced needle depth technique showed promise in achieving desired results of pulpal anesthesia with a reduced risk for complications associated with the PSA block injection. Additional studies are recommended to achieve evidence-based support for this reduced needle depth technique. Full Article
b Identification and Root Cause Analysis of the Visible Particles Commonly Encountered in the Biopharmaceutical Industry By journal.pda.org Published On :: 2024-10-22T08:20:35-07:00 Visible particle is an important issue in the biopharmaceutical industry, and it may occur across all the stages in the life cycle of biologics. Upon the occurrence of visible particles, it is often necessary to conduct chemical identification and root cause analysis to safeguard the safety and efficacy of the biotherapeutic products. In this article, we present a number of typical particles and relevant root cause analysis in the categories of extrinsic, intrinsic, and inherent particles that are commonly encountered in the biopharma industry. In particular, the optical images of particles obtained both in situ and after isolation are provided, along with spectral and elemental information. The particle identification was carried out with multiple microscopic and microspectroscopic techniques, including stereo optical microscopy, Fourier-transform infrared microscopy, confocal Raman microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Both commercial and in-house spectral databases were used for comparison and identification. In addition to particle identification, we placed significant efforts on the root cause analysis of the addressed particles with the intention to provide a relatively whole picture of the particle-related issues and practical references to particle mitigation for our peers in the biopharmaceutical industry. Full Article
b Impact of Dimensional Variability of Primary Packaging Materials on the Break-Loose and Gliding Forces of Prefilled Syringes By journal.pda.org Published On :: 2024-10-22T08:20:35-07:00 A prefilled syringe (PFS) should be able to be adequately and consistently extruded during injection for optimal safe drug delivery and accurate dosing. To facilitate appropriate break-loose and gliding forces (BLGFs) required during injection, certain primary packaging materials (PPMs) such as the syringe barrel and plunger are usually coated with silicone oil, which acts as a lubricant. Due to its direct contact with drug, silicone oil can increase the number of particles in the syringe, which could lead to adverse interactions. Compliance with regulatory-defined silicone oil quantities in certain drug products, such as ophthalmics, presents a trade-off with the necessity for desirable low and consistent BLGF. In addition to its siliconization, the dimensional accuracy of the PPM has an important role in controlling the BLGF. The dimensions of the PPM are individualized depending on the product and its design and have certain tolerances that must be met during manufacturing. Most studies on ophthalmics focused on the adverse interactions between silicone oil and the drug. To the authors' knowledge, there have been no public studies so far that have investigated the impact of the dimensional variability of the PPM on the BLGF in ophthalmic PFSs. In this study, we applied advanced optical shaft and tactile measuring technologies to investigate this impact. The syringes investigated were first sampled during aseptic production and tested for the BLGF. Subsequently, defined dimensions of the PPM were measured individually. The results showed that the dimensional variability of the PPM can have a negative impact on the BLGF, despite their conformity to specifications, which indicates that the currently available market quality of PPMs is improvable for critical drug products such as ophthalmics. This study could serve as an approach to define product-specific requirements for primary packaging combinations and thus appropriate specifications based on data during the development stage of drug products. Full Article
b Comparison of Binary Alcohol/Water Solvent Systems to Blood for Extractions of Blood-Contacting Medical Devices By journal.pda.org Published On :: 2024-10-22T08:20:35-07:00 The analysis of extractables and leachables and subsequent risk assessment is an important aspect of the determination of biocompatibility for many medical devices. Leachable chemicals have the potential to pose a toxicological risk to patients, and therefore it is required that they be adequately characterized and assessed for potential safety concerns. One important consideration in the assessment of leachables is the choice of a suitable simulating solvent intended to replicate the use condition for the device and its biological environment. This aspect of study design is especially difficult for blood-contacting medical devices due to the complexity of simulating the biological matrix. This publication reports a comparison of the extracting power of different binary solvent mixtures and saline in comparison with whole blood for a bloodline tubing set connected to a hemodialyzer. Ten different known extractables, spanning a range of physicochemical properties and molecular weights, were quantified. The results indicated that for low-molecular-weight analytes, a suitable exaggeration for whole blood can be obtained using a low-concentration ethanol/water mixture (20%), and in general, extracted quantity increases with the concentration of alcohol cosolvent. For polyvinylpyrrolidone, the opposite trend was observed, as solubility of the polymer was found to decrease with increasing alcohol concentration, resulting in lower extracted quantities at high alcohol concentrations. Analysis of ethanol/water concentrations in the extract solutions post extraction indicated no change in solvent composition. Full Article
b Degradation of Obidoxime Chloride Solution for Injection upon Long-Term Storage under Field Conditions of Mediterranean Climate vs the Controlled Environment By journal.pda.org Published On :: 2024-10-22T08:20:35-07:00 Obidoxime chloride is an antidote for nerve gas intoxication. As an emergency medicine, it is being stored by the Israel Defense Forces (IDF) scattered throughout Israel in depots without a controlled environment (field conditions), thus being exposed to high and fluctuating temperatures. These conditions do not meet the manufacturer’s requirements. In addition, due to possible supply shortages, the utilization of expired batches was suggested. The current work investigated these matters. Long-term (15 years) storage under different conditions was initiated. Chemical stability and toxicity in rats were assessed. No difference was found between field conditions vs the controlled environment. The obidoxime assay remained >95% for 5 years and >90% for 7 years. The pH remained above the lower specification limit for 7–8 years. The major degradation product, 4-pyridinealdoxime, surpassed the allowed limit at 5 years. The content of total unknown impurities reached its maximum allowed by the IDF limit at 4–5 years. Threefold higher than clinically utilized doses of valid-to-date Toxogonin batches administered to rats did not cause any abnormality. However, expired batches produced significant toxic effects. Although no difference was found between storage of obidoxime ampoules when adhering to manufacturer’s recommendations vs field conditions, accumulation of degradants over the limit allowed by the IDF at 4–5 years of storage and the toxicity of the expired batches observed in rats led the IDF to a decision to shorten the shelf-life of this product from 5 to 4 years when stored in an uncontrolled environment of the Mediterranean climate. Full Article
b 2024 September/October Editorial By journal.pda.org Published On :: 2024-10-22T08:20:35-07:00 Full Article
b NEAT1 promotes genome stability via m6A methylation-dependent regulation of CHD4 [Research Papers] By genesdev.cshlp.org Published On :: 2024-10-16T07:18:56-07:00 Long noncoding (lnc)RNAs emerge as regulators of genome stability. The nuclear-enriched abundant transcript 1 (NEAT1) is overexpressed in many tumors and is responsive to genotoxic stress. However, the mechanism that links NEAT1 to DNA damage response (DDR) is unclear. Here, we investigate the expression, modification, localization, and structure of NEAT1 in response to DNA double-strand breaks (DSBs). DNA damage increases the levels and N6-methyladenosine (m6A) marks on NEAT1, which promotes alterations in NEAT1 structure, accumulation of hypermethylated NEAT1 at promoter-associated DSBs, and DSB signaling. The depletion of NEAT1 impairs DSB focus formation and elevates DNA damage. The genome-protective role of NEAT1 is mediated by the RNA methyltransferase 3 (METTL3) and involves the release of the chromodomain helicase DNA binding protein 4 (CHD4) from NEAT1 to fine-tune histone acetylation at DSBs. Our data suggest a direct role for NEAT1 in DDR. Full Article
b YY1 knockout in pro-B cells impairs lineage commitment, enabling unusual hematopoietic lineage plasticity [Research Papers] By genesdev.cshlp.org Published On :: 2024-10-16T07:18:56-07:00 During B-cell development, cells progress through multiple developmental stages, with the pro-B-cell stage defining commitment to the B-cell lineage. YY1 is a ubiquitous transcription factor that is capable of both activation and repression functions. We found here that knockout of YY1 at the pro-B-cell stage eliminates B lineage commitment. YY1 knockout pro-B cells can generate T lineage cells in vitro using the OP9-DL4 feeder system and in vivo after injection into sublethally irradiated Rag1–/– mice. These T lineage-like cells lose their B lineage transcript profile and gain a T-cell lineage profile. Single-cell RNA-seq experiments showed that as YY1 knockout pro-B cells transition into T lineage cells in vitro, various cell clusters adopt transcript profiles representing a multiplicity of hematopoietic lineages, indicating unusual lineage plasticity. In addition, YY1 KO pro-B cells in vivo can give rise to other hematopoietic lineages in vivo. Evaluation of RNA-seq, scRNA-seq, ChIP-seq, and scATAC-seq data indicates that YY1 controls numerous chromatin-modifying proteins leading to increased accessibility of alternative lineage genes in YY1 knockout pro-B cells. Given the ubiquitous nature of YY1 and its dual activation and repression functions, YY1 may regulate commitment in multiple cell lineages. Full Article
b Decoding biology with massively parallel reporter assays and machine learning [Reviews] By genesdev.cshlp.org Published On :: 2024-10-16T07:18:56-07:00 Massively parallel reporter assays (MPRAs) are powerful tools for quantifying the impacts of sequence variation on gene expression. Reading out molecular phenotypes with sequencing enables interrogating the impact of sequence variation beyond genome scale. Machine learning models integrate and codify information learned from MPRAs and enable generalization by predicting sequences outside the training data set. Models can provide a quantitative understanding of cis-regulatory codes controlling gene expression, enable variant stratification, and guide the design of synthetic regulatory elements for applications from synthetic biology to mRNA and gene therapy. This review focuses on cis-regulatory MPRAs, particularly those that interrogate cotranscriptional and post-transcriptional processes: alternative splicing, cleavage and polyadenylation, translation, and mRNA decay. Full Article
b Harnessing brain-body communication to understand cancer [Special Section: Symposium Outlook] By genesdev.cshlp.org Published On :: 2024-10-16T07:18:56-07:00 Solid tumors that arise in the body interact with neurons, which influences cancer progression and treatment response. Here, we discuss key questions in the field, including defining the nature of interactions between tumors and neural circuits and defining how neural signals shape the tumor microenvironment. This information will allow us to optimally target neural signaling to improve outcomes for cancer patients. Full Article
b Temperature matters: the potential impact of thermoregulatory mechanisms in brain-body physiology [Special Section: Symposium Outlook] By genesdev.cshlp.org Published On :: 2024-10-16T07:18:56-07:00 Thermoregulation, responsible for maintaining a stable core temperature during wide fluctuations in external and internal thermal environments, is an iconic homeostatic process. However, we suggest that despite its fundamental physiological significance, the potential for required cool housing temperatures and thermoregulatory mechanisms to influence the interpretation of experimental data is not sufficiently appreciated. Moreover, although it is generally assumed that the major thermoregulatory pathways are well understood, here we discuss new research that suggests otherwise and reveals the emergence of a new wave of exciting ideas for this "old" field of research. Full Article
b Bridging brain and body in cancer [Special Section: Symposium Outlook] By genesdev.cshlp.org Published On :: 2024-10-16T07:18:56-07:00 Recent work has highlighted the central role the brain–body axis plays in not only maintaining organismal homeostasis but also coordinating the body's response to immune and inflammatory insults. Here, we discuss how science is poised to address the many ways that our brain is directly involved with disease. In particular, we feel that combining cutting-edge tools in neuroscience with translationally relevant models of cancer will be critical to understanding how the brain and tumors communicate and modulate each other's behavior. Full Article
b The area postrema: a critical mediator of brain-body interactions [Special Section: Symposium Outlook] By genesdev.cshlp.org Published On :: 2024-10-16T07:18:56-07:00 The dorsal vagal complex contains three structures: the area postrema, the nucleus tractus solitarii, and the dorsal motor nucleus of the vagus. These structures are tightly linked, both anatomically and functionally, and have important yet distinct roles in not only conveying peripheral bodily signals to the rest of the brain but in the generation of behavioral and physiological responses. Reports on the new discoveries in these structures were highlights of the symposium. In this outlook, we focus on the roles of the area postrema in mediating brain–body interactions and its potential utility as a therapeutic target, especially in cancer cachexia. Full Article
b Cancer neuroscience at the brain-body interface [Special Section: Symposium Outlook] By genesdev.cshlp.org Published On :: 2024-10-16T07:18:56-07:00 Our approaches toward understanding cancer have evolved beyond cell-intrinsic and local microenvironmental changes within the tumor to encompass how the cancer interfaces with the entire host organism. The nervous system is uniquely situated at the interface between the brain and body, constantly receiving and sending signals back and forth to maintain homeostasis and respond to salient stimuli. It is becoming clear that various cancers disrupt this dialog between the brain and body via both neuronal and humoral routes, leading to aberrant brain activity and accelerated disease. In this outlook, I discuss this view of cancer as a homeostatic challenge, emphasize cutting-edge work, and provide outstanding questions that need to be answered to move the field forward. Full Article
b Dysregulating mTORC1-4E-BP2 signaling in GABAergic interneurons impairs hippocampus-dependent learning and memory [RESEARCH PAPERS] By learnmem.cshlp.org Published On :: 2024-10-28T08:52:55-07:00 Memory formation is contingent on molecular and structural changes in neurons in response to learning stimuli—a process known as neuronal plasticity. The initiation step of mRNA translation is a gatekeeper of long-term memory by controlling the production of plasticity-related proteins in the brain. The mechanistic target of rapamycin complex 1 (mTORC1) controls mRNA translation, mainly through phosphorylation of the eukaryotic initiation factor 4E (eIF4E)-binding proteins (4E-BPs) and ribosomal protein S6 kinases (S6Ks). mTORC1 signaling decreases throughout brain development, starting from the early postnatal period. Here, we discovered that in mice, the age-dependent decrease in mTORC1 signaling occurs selectively in excitatory but not inhibitory neurons. Using a gene conditional knockout (cKO) strategy, we demonstrate that either up- or downregulating the mTORC1-4E-BP2 axis in GAD65 inhibitory interneurons, but not excitatory neurons, results in long-term object recognition and object location memory deficits. Our data indicate that the mTORC1 pathway in inhibitory but not excitatory neurons plays a key role in memory formation. Full Article
b The influence of categorical stimuli on relational memory binding [RESEARCH PAPERS] By learnmem.cshlp.org Published On :: 2024-10-31T09:40:31-07:00 Binding of arbitrary information into distinct memory representations that can be used to guide behavior is a hallmark of relational memory. What is and is not bound into a memory representation and how those things influence the organization of that representation remain topics of interest. While some information is intentionally and effortfully bound—often the information that is consistent with task goals or expectations about what information may be required later—other information appears to be bound automatically. The present set of experiments sought to investigate whether spatial memory would be systematically influenced by the presence and absence of distinct categories of stimuli on a spatial reconstruction task. In this task, participants must learn multiple item-location bindings and place each item back in its studied location after a short delay. Across three experiments, participants made significantly more within-category errors (i.e., misassigning one item to the location of a different item from the same category) than between-category errors (i.e., misassigning one item to the location of an item from a different category) when categories were perceptually or semantically distinct. These data reveal that category information contributed to the organization of the memory representation and influenced spatial reconstruction performance. Together, these results suggest that categorical information can influence memory organization, and not always to the benefit of overall task performance. Full Article
b A circular split nanoluciferase reporter for validating and screening putative internal ribosomal entry site elements [METHOD] By rnajournal.cshlp.org Published On :: 2024-10-16T07:18:13-07:00 Internal ribosomal entry sites (IRESs) recruit the ribosome to promote translation, typically in an m7G cap-independent manner. Although IRESs are well-documented in viral genomes, they have also been reported in mammalian transcriptomes, where they have been proposed to mediate cap-independent translation of mRNAs. However, subsequent studies have challenged the idea of these "cellular" IRESs. Current methods for screening and discovering IRES activity rely on a bicistronic reporter assay, which is prone to producing false positive signals if the putative IRES sequence has a cryptic promoter or cryptic splicing sites. Here, we report an assay for screening IRES activity using a genetically encoded circular RNA comprising a split nanoluciferase (nLuc) reporter. The circular split nLuc reporter is less susceptible to the various sources of false positives that adversely affect the bicistronic IRES reporter assay and provides a streamlined method for screening IRES activity. Using the circular split nLuc reporter, we find that nine reported cellular IRESs have minimal IRES activity. Overall, the circular split nLuc reporter offers a simplified approach for identifying and validating IRESs and exhibits reduced propensity for producing the types of false positives that can occur with the bicistronic reporter assay. Full Article
b High-resolution reconstruction of a C. elegans ribosome sheds light on evolutionary dynamics and tissue specificity [ARTICLE] By rnajournal.cshlp.org Published On :: 2024-10-16T07:18:13-07:00 Caenorhabditis elegans is an important model organism for human health and disease, with foundational contributions to the understanding of gene expression and tissue patterning in animals. An invaluable tool in modern gene expression research is the presence of a high-resolution ribosome structure, though no such structure exists for C. elegans. Here, we present a high-resolution single-particle cryogenic electron microscopy (cryo-EM) reconstruction and molecular model of a C. elegans ribosome, revealing a significantly streamlined animal ribosome. Many facets of ribosome structure are conserved in C. elegans, including overall ribosomal architecture and the mechanism of cycloheximide, whereas other facets, such as expansion segments and eL28, are rapidly evolving. We identify uL5 and uL23 as two instances of tissue-specific ribosomal protein paralog expression conserved in Caenorhabditis, suggesting that C. elegans ribosomes vary across tissues. The C. elegans ribosome structure will provide a basis for future structural, biochemical, and genetic studies of translation in this important animal system. Full Article
b Characterization and implementation of the MarathonRT template-switching reaction to expand the capabilities of RNA-seq [ARTICLE] By rnajournal.cshlp.org Published On :: 2024-10-16T07:18:13-07:00 End-to-end RNA-sequencing methods that capture 5'-sequence content without cumbersome library manipulations are of great interest, particularly for analysis of long RNAs. While template-switching methods have been developed for RNA sequencing by distributive short-read RTs, such as the MMLV RTs used in SMART-Seq methods, they have not been adapted to leverage the power of ultraprocessive RTs, such as those derived from group II introns. To facilitate this transition, we dissected the individual processes that guide the enzymatic specificity and efficiency of the multistep template-switching reaction carried out by RTs, in this case, by MarathonRT. Remarkably, this is the first study of its kind, for any RT. First, we characterized the nucleotide specificity of nontemplated addition (NTA) reaction that occurs when the RT extends past the RNA 5'-terminus. We then evaluated the binding specificity of specialized template-switching oligonucleotides, optimizing their sequences and chemical properties to guide efficient template-switching reaction. Having dissected and optimized these individual steps, we then unified them into a procedure for performing RNA sequencing with MarathonRT enzymes, using a well-characterized RNA reference set. The resulting reads span a six-log range in transcript concentration and accurately represent the input RNA identities in both length and composition. We also performed RNA-seq from total human RNA and poly(A)-enriched RNA, with short- and long-read sequencing demonstrating that MarathonRT enhances the discovery of unseen RNA molecules by conventional RT. Altogether, we have generated a new pipeline for rapid, accurate sequencing of complex RNA libraries containing mixtures of long RNA transcripts. Full Article
b lncRNA BC200 is processed into a stable Alu monomer [ARTICLE] By rnajournal.cshlp.org Published On :: 2024-10-16T07:18:13-07:00 The noncoding RNA BC200 is elevated in human cancers and is implicated in translation regulation as well as cell survival and proliferation. Upon BC200 overexpression, we observed correlated expression of a second, smaller RNA species. This RNA is expressed endogenously and exhibits cell-type-dependent variability relative to BC200. Aptamer-tagged expression constructs confirmed that the RNA is a truncated form of BC200, and sequencing revealed a modal length of 120 nt; thus, we refer to the RNA fragment as BC120. We present a methodology for accurate and specific detection of BC120 and establish that BC120 is expressed in several normal human tissues and is also elevated in ovarian cancer. BC120 exhibits remarkable stability relative to BC200 and is resistant to knockdown strategies that target the 3' unique sequence of BC200. Combined knockdown of BC200 and BC120 exhibits greater phenotypic impacts than knockdown of BC200 alone, and overexpression of BC120 negatively impacts translation of a GFP reporter, providing insight into a potential translational regulatory role for this RNA. The presence of a novel, truncated, and stable form of BC200 adds complexity to the investigation of this noncoding RNA that must be considered in future studies of BC200 and other related Alu RNAs. Full Article
b The small noncoding RNA Vaultrc5 is dispensable to mouse development [ARTICLE] By rnajournal.cshlp.org Published On :: 2024-10-16T07:18:13-07:00 Vault RNAs (vtRNAs) are evolutionarily conserved small noncoding RNAs transcribed by RNA polymerase III. Vault RNAs were initially described as components of the vault particle, but have since been assigned multiple vault-independent functions, including regulation of PKR activity, apoptosis, autophagy, lysosome biogenesis, and viral particle trafficking. The full-length transcript has also been described as a noncanonical source of miRNAs, which are processed in a DICER-dependent manner. As central molecules in vault-dependent and independent processes, vtRNAs have been attributed numerous biological roles, including regulation of cell proliferation and survival, response to viral infections, drug resistance, and animal development. Yet, their impact to mammalian physiology remains largely unexplored. To study vault RNAs in vivo, we generated a mouse line with a conditional Vaultrc5 loss-of-function allele. Because Vaultrc5 is the sole murine vtRNA, this allele enables the characterization of the physiological requirements of this conserved class of small regulatory RNAs in mammals. Using this strain, we show that mice constitutively null for Vaultrc5 are viable and histologically normal but have a slight reduction in platelet counts, pointing to a potential role for vtRNAs in hematopoiesis. This work paves the way for further in vivo characterizations of this abundant but mysterious RNA molecule. Specifically, it enables the study of the biological consequences of constitutive or lineage-specific Vaultrc5 deletion and of the physiological requirements for an intact Vaultrc5 during normal hematopoiesis or in response to cellular stresses such as oncogene expression, viral infection, or drug treatment. Full Article
b The antivirulent Staphylococcal sRNA SprC regulates CzrB efflux pump to adapt its response to zinc toxicity [ARTICLE] By rnajournal.cshlp.org Published On :: 2024-10-16T07:18:13-07:00 Bacterial regulatory RNAs (sRNAs) are important players to control gene expression. In Staphylococcus aureus, SprC is an antivirulent trans-acting sRNA known to base-pair with the major autolysin atl mRNA, preventing its translation. Using MS2-affinity purification coupled with RNA sequencing, we looked for its sRNA-RNA interactome and identified 14 novel mRNA targets. In vitro biochemical investigations revealed that SprC binds two of them, czrB and deoD, and uses a single accessible region to regulate its targets, including Atl translation. Unlike Atl regulation, the characterization of the SprC-czrB interaction pinpointed a destabilization of the czrAB cotranscript, leading to a decrease of the mRNA level that impaired CzrB zinc efflux pump expression. On a physiological standpoint, we showed that SprC expression is detrimental to combat against zinc toxicity. In addition, phagocyctosis assays revealed a significant, but moderate, increase of czrB mRNA levels in a sprC-deleted mutant, indicating a functional link between SprC and czrB upon internalization in macrophages, and suggesting a role in resistance to both oxidative and zinc bursts. Altogether, our data uncover a novel pathway in which SprC is implicated, highlighting the multiple strategies used by S. aureus to balance virulence using an RNA regulator. Full Article
b Abolished frameshifting for predicted structure-stabilizing SARS-CoV-2 mutants: implications to alternative conformations and their statistical structural analyses [ARTICLE] By rnajournal.cshlp.org Published On :: 2024-10-16T07:18:13-07:00 The SARS-CoV-2 frameshifting element (FSE) has been intensely studied and explored as a therapeutic target for coronavirus diseases, including COVID-19. Besides the intriguing virology, this small RNA is known to adopt many length-dependent conformations, as verified by multiple experimental and computational approaches. However, the role these alternative conformations play in the frameshifting mechanism and how to quantify this structural abundance has been an ongoing challenge. Here, we show by DMS and dual-luciferase functional assays that previously predicted FSE mutants (using the RAG graph theory approach) suppress structural transitions and abolish frameshifting. Furthermore, correlated mutation analysis of DMS data by three programs (DREEM, DRACO, and DANCE-MaP) reveals important differences in their estimation of specific RNA conformations, suggesting caution in the interpretation of such complex conformational landscapes. Overall, the abolished frameshifting in three different mutants confirms that all alternative conformations play a role in the pathways of ribosomal transition. Full Article
b Branch site recognition by the spliceosome [REVIEW] By rnajournal.cshlp.org Published On :: 2024-10-16T07:18:13-07:00 The spliceosome is a eukaryotic multimegadalton RNA–protein complex that removes introns from transcripts. The spliceosome ensures the selection of each exon-intron boundary through multiple recognition events. Initially, the 5' splice site (5' SS) and branch site (BS) are bound by the U1 small nuclear ribonucleoprotein (snRNP) and the U2 snRNP, respectively, while the 3' SS is mostly determined by proximity to the branch site. A large number of splicing factors recognize the splice sites and recruit the snRNPs before the stable binding of the snRNPs occurs by base-pairing the snRNA to the transcript. Fidelity of this process is crucial, as mutations in splicing factors and U2 snRNP components are associated with many diseases. In recent years, major advances have been made in understanding how splice sites are selected in Saccharomyces cerevisiae and humans. Here, I review and discuss the current understanding of the recognition of splice sites by the spliceosome with a focus on recognition and binding of the branch site by the U2 snRNP in humans. Full Article
b The noninvasive ventilation outcomes score in patients requiring NIV for COPD exacerbation without prior evidence of airflow obstruction By beta.openres.ersjournals.com Published On :: 2024-11-11T01:50:25-08:00 Introduction Exacerbation of COPD complicated by respiratory acidaemia is the commonest indication for noninvasive ventilation (NIV). The NIV outcomes (NIVO) score offers the best estimate of survival for those ventilated. Unfortunately, two-thirds of cases of COPD are unrecognised, and patients may present without COPD having been confirmed by spirometry. Methods In the 10-centre NIVO validation study there was no pre-admission spirometry in 111 of 844 consecutive patients (termed "clinical diagnosis" patients). We compared the performance of the NIVO, DECAF and CURB-65 scores for in-hospital mortality in the clinical diagnosis cohort. Usual clinical practice was not influenced, but confirmation of COPD in the year following discharge was captured. Results In the clinical diagnosis cohort, in-hospital mortality was 19.8% and rose incrementally across the NIVO risk categories, consistent with the NIVO validation cohort. NIVO showed good discrimination in the clinical diagnosis cohort: area under the receiver operating curve 0.724, versus 0.79 in the NIVO validation cohort. At 1 year after discharge, 41 of 89 clinical diagnosis patients had undertaken diagnostic spirometry; 33 of 41 had confirmation of airflow obstruction (forced expiratory volume in 1 s/(forced) vital capacity <0.7), meaning the diagnosis of COPD was incorrect in 19.5% of cases. Discussion These data support the use of the NIVO score in patients with a "clinical diagnosis" of COPD. NIVO can help guide shared decision-making, assess risk-adjusted outcomes by centre and challenge prognostic pessimism. Accurate diagnosis is critical to ensure that acute and long-term treatment is optimised; this study highlights failings in the follow-up of such patients. Full Article
b Characteristics of exacerbators in the US Bronchiectasis and NTM Research Registry: a cross-sectional study By beta.openres.ersjournals.com Published On :: 2024-11-11T01:50:25-08:00 Background Exacerbations of noncystic fibrosis bronchiectasis (bronchiectasis) are associated with reduced health-related quality of life and increased mortality, likelihood of hospitalisation and lung function decline. This study investigated patient clinical characteristics associated with exacerbation frequency. Methods A cross-sectional cohort study of patients ≥18 years with bronchiectasis enrolled in the US Bronchiectasis and Nontuberculous Mycobacteria (NTM) Research Registry (BRR) September 2008–March 2020. Patients were stratified by exacerbation frequency in their 2 years before enrolment. Patient demographics, respiratory symptoms, healthcare resource utilisation, microbiology, modified bronchiectasis severity index (mBSI) and select comorbidities were collected at enrolment. Patient characteristics associated with exacerbation frequency were assessed using a negative binomial model. Results The study included 2950 patients (mean age 65.6 years; 79.1% female). Frequency of moderate to severe airway obstruction (forced expiratory volume in 1 s (FEV1) % predicted <50%; most recent measure) was 15.9%, 17.8%, and 24.6% in patients with 1, 2, and ≥3 exacerbations versus 8.9% in patients with 0 exacerbations; severe disease (mBSI) was 27.8%, 24.2% and 51.1% versus 13.2%; respiratory hospitalisation was 24.5%, 33.0% and 36.5% versus 4.1%; and Pseudomonas aeruginosa infection was 18.8%, 23.4% and 35.2% versus 11.9%. In multivariable model analysis, respiratory hospitalisation, cough, haemoptysis, P. aeruginosa, younger age, lower FEV1% predicted, asthma, and gastro-oesophageal reflux disease were associated with more exacerbations. Conclusions These findings demonstrate a high disease burden, including increased respiratory symptoms, healthcare resource utilisation, and P. aeruginosa infection in patients with bronchiectasis and multiple exacerbations. Full Article
b TB or not TB: does AI have an answer for children? By erj.ersjournals.com Published On :: 2024-11-07T00:35:56-08:00 Extract In 2021, the World Health Organization (WHO) issued recommendations for the use of artificial intelligence (AI), affirming the technology could be used instead of human readers for the interpretation of chest radiograph (CXR) images for the screening and triage of tuberculosis (TB), marking a historic precedent for a guideline on AI in health [1]. The forward-looking guidance highlights the utility of CXR in TB, despite past reluctance from WHO to use it in TB programmes [2]. Employing CXR in a diagnostic algorithm can identify people with subclinical TB who are asymptomatic but have lung pathology suggestive of TB, and refer them for testing and diagnosis [3]. Full Article
b Ensuring availability of respiratory medicines in times of European drug shortages By erj.ersjournals.com Published On :: 2024-11-07T00:35:56-08:00 Extract It is of utmost importance that medicines are available at all times for our patients. Historically, medication unavailability has typically, if not exclusively, affected low- and middle-income countries [1]. More recently however, drug shortages have also been reported in high-income European countries [2]. Drug shortages have negative health consequences for patients [3], and a profound economic impact, with the need to resort to more expensive alternatives and demands on healthcare professionals’ time to find, prescribe and dispense alternatives [4]. Full Article
b CPAP recall and cancer risk: should we be concerned? By erj.ersjournals.com Published On :: 2024-11-07T00:35:56-08:00 Extract There is an expanding literature on the association between obstructive sleep apnoea (OSA) and cancer risk [1, 2]. Evidence is growing from population- and clinic-based cohort studies that the severity of OSA and sleep-related hypoxaemia may adversely affect both overall cancer risk and incidence of certain cancers [3–7]. These clinical findings are supported by the identification of the intermediate mechanisms by which intermittent hypoxia and sleep fragmentation, the hallmark features of OSA, might promote oncogenesis, tumour growth and metastasis [8]. Although studies have shown a relationship between OSA and cancer, few have evaluated whether the risk of cancer development or progression in patients with OSA is modified by continuous positive airway pressure (CPAP) therapy (the primary treatment for OSA) [1, 2]. Full Article
b The treatment of latent tuberculosis infection in migrants in primary care versus secondary care By erj.ersjournals.com Published On :: 2024-11-07T00:35:56-08:00 Extract With a disproportionate burden of tuberculosis (TB) amongst migrants in Europe [1], Burman et al. [2] have highlighted the pressing need for alternative approaches to make TB infection (TBI) screening comprehensive and accessible. Across high-income Organisation for Economic Co-operation and development countries, a median of 52% of TB cases occur in foreign-born individuals, who are at their highest risk of developing TB disease within the first 5 years of migration [3]. Molecular epidemiological studies indicate that the majority of these cases occur as a result of TBI reactivation, often acquired overseas [4]. Within the UK, overseas-born migrants have a 14-fold higher TB incidence than UK-born individuals [5]. The World Health Organization therefore recommends that migrants from countries with a high TB burden may be prioritised for TBI screening [6, 7]. Full Article
b Decoding genetic susceptibility to Pseudomonas aeruginosa infections in cystic fibrosis By erj.ersjournals.com Published On :: 2024-11-07T00:35:56-08:00 Extract In cystic fibrosis (CF), Pseudomonas aeruginosa acquisition represents a turning point in disease progression. The presence of chronic P. aeruginosa infection is associated with worsening lung function and increased risk of earlier death, whereas treatment substantially improves lung function and survival [1, 2]. Efforts to diagnose and eradicate early P. aeruginosa provide lasting benefits for children with CF [3, 4]. However, the timing of infection varies considerably between individuals with CF, treatment centres [5, 6], and different birth cohorts of people with the disease [7, 8]. Full Article
b Accuracy of CAD4TB (Computer-Aided Detection for Tuberculosis) on paediatric chest radiographs By erj.ersjournals.com Published On :: 2024-11-07T00:35:56-08:00 Background Computer-aided detection (CAD) systems hold promise for improving tuberculosis (TB) detection on digital chest radiographs. However, data on their performance in exclusively paediatric populations are scarce. Methods We conducted a retrospective diagnostic accuracy study evaluating the performance of CAD4TBv7 (Computer-Aided Detection for Tuberculosis version 7) using digital chest radiographs from well-characterised cohorts of Gambian children aged <15 years with presumed pulmonary TB. The children were consecutively recruited between 2012 and 2022. We measured CAD4TBv7 performance against a microbiological reference standard (MRS) of confirmed TB, and also performed Bayesian latent class analysis (LCA) to address the inherent limitations of the MRS in children. Diagnostic performance was assessed using the area under the receiver operating characteristic curve (AUROC) and point estimates of sensitivity and specificity. Results A total of 724 children were included in the analysis, with confirmed TB in 58 (8%), unconfirmed TB in 145 (20%) and unlikely TB in 521 (72%). Using the MRS, CAD4TBv7 showed an AUROC of 0.70 (95% CI 0.60–0.79), and demonstrated sensitivity and specificity of 19.0% (95% CI 11–31%) and 99.0% (95% CI 98.0–100.0%), respectively. Applying Bayesian LCA with the assumption of conditional independence between tests, sensitivity and specificity estimates for CAD4TBv7 were 42.7% (95% CrI 29.2–57.5%) and 97.9% (95% CrI 96.6–98.8%), respectively. When allowing for conditional dependence between culture and Xpert assay, CAD4TBv7 demonstrated a sensitivity of 50.3% (95% CrI 32.9–70.0%) and specificity of 98.0% (95% CrI 96.7–98.9%). Conclusion Although CAD4TBv7 demonstrated high specificity, its suboptimal sensitivity underscores the crucial need for optimisation of CAD4TBv7 for detecting TB in children. Full Article
b Association between a recalled positive airway pressure device and incident cancer: a population-based study By erj.ersjournals.com Published On :: 2024-11-07T00:35:55-08:00 Background The real-world consequences of a Philips Respironics recall for positive airway pressure (PAP) devices distributed between 2009 and 2021 are unknown. Methods We conducted a retrospective population-based study using health administrative databases (Ontario, Canada) on all new adult PAP users identified through the provincial funding system, free of cancer at baseline, who initiated (claimed) PAP treatment between 2012 and 2018. Everyone was followed from the PAP claim date to the earliest of incident cancer diagnosis, death or end of follow-up (March 2022). We used inverse probability of treatment weighting to balance baseline characteristics between individuals on recalled devices and those on devices from other manufacturers. Weighted hazard ratios of incident cancer were compared between groups. Results Of 231 692 individuals identified, 58 204 (25.1%) claimed recalled devices and 173 488 (74.9%) claimed devices from other manufacturers. A meaningful baseline difference between groups (standardised difference ≥0.10) was noted only by location-relevant covariates; other variables were mostly equally distributed (standardised differences ≤0.06). Over a median (interquartile range) follow-up of 6.3 (4.9–8.0) years, 11 166 (4.8%) developed cancer: unadjusted rates per 10 000 person-years of 78.8 (95% CI 76.0–81.7) in the recall group versus 74.0 (95% CI 72.4–75.6) in others (p=0.0034). Propensity score weighting achieved excellent balance in baseline characteristics between groups (standardised differences ≤0.07). On a weighted sample, there was no statistical difference in the hazard of incident cancer between groups: cause-specific hazard ratio (recalled versus others) 0.97 (95% CI 0.89–1.06). Conclusion In our real-world population study, compared to other manufacturers and adjusting for confounders, recalled Philips Respironics PAP devices do not appear to be independently associated with developing cancer. Full Article
b Genome-wide association study of susceptibility to Pseudomonas aeruginosa infection in cystic fibrosis By erj.ersjournals.com Published On :: 2024-11-07T00:35:55-08:00 Background Pseudomonas aeruginosa is a common pathogen that contributes to progressive lung disease in cystic fibrosis (CF). Genetic factors other than CF-causing CFTR (CF transmembrane conductance regulator) variations contribute ~85% of the variation in chronic P. aeruginosa infection age in CF according to twin studies, but the susceptibility loci remain unknown. Our objective is to advance understanding of the genetic basis of host susceptibility to P. aeruginosa infection. Materials and methods We conducted a genome-wide association study of chronic P. aeruginosa infection age in 1037 Canadians with CF. We subsequently assessed the genetic correlation between chronic P. aeruginosa infection age and lung function through polygenic risk score (PRS) analysis and inferred their causal relationship through bidirectional Mendelian randomisation analysis. Results Two novel genome-wide significant loci with lead single nucleotide polymorphisms (SNPs) rs62369766 (chr5p12; p=1.98x10–8) and rs927553 (chr13q12.12; p=1.91x10–8) were associated with chronic P. aeruginosa infection age. The rs62369766 locus was validated using an independent French cohort (n=501). Furthermore, the PRS constructed from CF lung function-associated SNPs was significantly associated with chronic P. aeruginosa infection age (p=0.002). Finally, our analysis presented evidence for a causal effect of lung function on chronic P. aeruginosa infection age (β=0.782 years, p=4.24x10–4). In the reverse direction, we observed a moderate effect (β=0.002, p=0.012). Conclusions We identified two novel loci that are associated with chronic P. aeruginosa infection age in individuals with CF. Additionally, we provided evidence of common genetic contributors and a potential causal relationship between P. aeruginosa infection susceptibility and lung function in CF. Therapeutics targeting these genetic factors may delay the onset of chronic infections, which account for significant remaining morbidity in CF. Full Article
b Reassessing Halm's clinical stability criteria in community-acquired pneumonia management By erj.ersjournals.com Published On :: 2024-11-07T00:35:55-08:00 Background Halm's clinical stability criteria have long guided antibiotic treatment and hospital discharge decisions for patients hospitalised with community-acquired pneumonia (CAP). Originally introduced in 1998, these criteria were established based on a relatively small and select patient population. Consequently, our study aims to reassess their applicability in the management of CAP in a contemporary real-world setting. Methods This cohort study included 2918 immunocompetent patients hospitalised with CAP from three hospitals in Denmark between 2017 and 2020. The primary outcome was time to achieve clinical stability as defined by Halm's criteria. Additionally, we examined recurrence of clinical instability and severe complications. Cumulative incidence function or Kaplan–Meier survival curves were used to analyse these outcomes, considering competing risks. Results The study population primarily comprised elderly individuals (median age 75 years) with significant comorbidities. The median time to clinical stability according to Halm's criteria was 4 days, with one-fifth experiencing recurrence of instability after early clinical response (stability within 3 days). Severe complications within 30 days mainly comprised mortality, with rates of 5.1% (64/1257) overall in those with early clinical response, 1.7% (18/1045) in the subgroup without do-not-resuscitate orders and 17.3% (276/1595) among the rest. Conclusion Halm's clinical stability criteria effectively classify CAP patients with different disease courses, yet achieving stability required more time in this ageing population with substantial comorbidities and more severe disease. Early clinical response indicates reduced risk of complications, especially in those without do-not-resuscitate orders. Full Article
b Treatment of latent tuberculosis infection in migrants in primary care versus secondary care By erj.ersjournals.com Published On :: 2024-11-07T00:35:55-08:00 Background Control of latent tuberculosis infection (LTBI) is a priority in the World Health Organization strategy to eliminate TB. Many high-income, low TB incidence countries have prioritised LTBI screening and treatment in recent migrants. We tested whether a novel model of care, based entirely within primary care, was effective and safe compared to secondary care. Methods This was a pragmatic cluster-randomised, parallel group, superiority trial (ClinicalTrials.gov: NCT03069807) conducted in 34 general practices in London, UK, comparing LTBI treatment in recent migrants in primary care to secondary care. The primary outcome was treatment completion, defined as taking ≥90% of antibiotic doses. Secondary outcomes included treatment acceptance, adherence, adverse effects, patient satisfaction, TB incidence and a cost-effectiveness analysis. Analyses were performed on an intention-to-treat basis. Results Between September 2016 and May 2019, 362 recent migrants with LTBI were offered treatment and 276 accepted. Treatment completion was similar in primary and secondary care (82.6% versus 86.0%; adjusted OR (aOR) 0.64, 95% CI 0.31–1.29). There was no difference in drug-induced liver injury between primary and secondary care (0.7% versus 2.3%; aOR 0.29, 95% CI 0.03–2.84). Treatment acceptance was lower in primary care (65.2% (146/224) versus 94.2% (130/138); aOR 0.10, 95% CI 0.03–0.30). The estimated cost per patient completing treatment was lower in primary care, with an incremental saving of GBP 315.27 (95% CI 313.47–317.07). Conclusions The treatment of LTBI in recent migrants within primary care does not result in higher rates of treatment completion but is safe and costs less when compared to secondary care. Full Article
b Characterization and Prediction of Organic Anion Transporting Polypeptide 1B Activity in Prostate Cancer Patients on Abiraterone Acetate Using Endogenous Biomarker Coproporphyrin I [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 are important hepatic transporters. We previously identified OATP1B3 being critically implicated in the disposition of abiraterone. We aimed to further investigate the effects of abiraterone on the activities of OATP1B1 and OATP1B3 utilizing a validated endogenous biomarker coproporphyrin I (CP-I). We used OATP1B-transfected cells to characterize the inhibitory potential of abiraterone against OATP1B-mediated uptake of CP-I. Inhibition constant (Ki) was incorporated into our physiologically based pharmacokinetic (PBPK) modeling to simulate the systemic exposures of CP-I among cancer populations receiving either our model-informed 500 mg or clinically approved 1000 mg abiraterone acetate (AA) dosage. Simulated data were compared with clinical CP-I concentrations determined among our nine metastatic prostate cancer patients receiving 500 mg AA treatment. Abiraterone inhibited OATP1B3-mediated, but not OATP1B1-mediated, uptake of CP-I in vitro, with an estimated Ki of 3.93 μM. Baseline CP-I concentrations were simulated to be 0.81 ± 0.26 ng/ml and determined to be 0.72 ± 0.16 ng/ml among metastatic prostate cancer patients, both of which were higher than those observed for healthy subjects. PBPK simulations revealed an absence of OATP1B3-mediated interaction between abiraterone and CP-I. Our clinical observations confirmed that CP-I concentrations remained comparable to baseline levels up to 12 weeks post 500 mg AA treatment. Using CP-I as an endogenous biomarker, we identified the inhibition of abiraterone on OATP1B3 but not OATP1B1 in vitro, which was predicted and observed to be clinically insignificant. We concluded that the interaction risk between AA and substrates of OATP1Bs is low. SIGNIFICANCE STATEMENT The authors used the endogenous biomarker coproporphyrin I (CP-I) and identified abiraterone as a moderate inhibitor of organic anion transporting polypeptide (OATP) 1B3 in vitro. Subsequent physiologically based pharmacokinetic (PBPK) simulations and clinical observations suggested an absence of OATP1B-mediated interaction between abiraterone and CP-I among prostate cancer patients. This multipronged study concluded that the interaction risk between abiraterone acetate and substrates of OATP1Bs is low, demonstrating the application of PBPK-CP-I modeling in predicting OATP1B-mediated interaction implicating abiraterone. Full Article
b Correlations of Long Noncoding RNA HNF4A-AS1 Alternative Transcripts with Liver Diseases and Drug Metabolism [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Hepatocyte nuclear factor 4 alpha antisense 1 (HNF4A-AS1) is a long noncoding RNA (lncRNA) gene physically located next to the transcription factor HNF4A gene in the human genome. Its transcription products have been reported to inhibit the progression of hepatocellular carcinoma (HCC) and negatively regulate the expression of cytochrome P450s (CYPs), including CYP1A2, 2B6, 2C9, 2C19, 2E1, and 3A4. By altering CYP expression, lncRNA HNF4A-AS1 also contributes to the susceptibility of drug-induced liver injury. Thus, HNF4A-AS1 lncRNA is a promising target for controlling HCC and modulating drug metabolism. However, HNF4A-AS1 has four annotated alternative transcripts in the human genome browsers, and it is unclear which transcripts the small interfering RNAs or small hairpin RNAs used in the previous studies are silenced and which transcripts should be used as the target. In this study, four annotated and two newly identified transcripts were confirmed. These six transcripts showed different expression levels in different liver disease conditions, including metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, and obesity. The expression patterns of all HNF4A-AS1 transcripts were further investigated in liver cell growth from human embryonic stem cells to matured hepatocyte-like cells, HepaRG differentiation, and exposure to rifampicin treatment. Several HNF4A-AS1 transcripts highly displayed correlations with these situations. In addition, some of the HNF4A-AS1 transcripts also showed a strong correlation with CYP3A4 during HepaRG maturation and rifampicin exposure. Our findings provide valuable insights into the specific roles of HNF4A-AS1 transcripts, paving the way for more targeted therapeutic strategies for liver diseases and drug metabolism. SIGNIFICANCE STATEMENT This study explores the alternative transcripts of HNF4A-AS1, showing how their expression changes in different biological conditions, from various liver diseases to the growth and differentiation of hepatocytes and drug metabolism. The generated knowledge is essential for understanding the independent roles of different transcripts from the same lncRNA in different liver diseases and drug metabolism situations. Full Article
b Molecular Mechanisms for the Selective Transport of Dichlorofluorescein by Human Organic Anion Transporting Polypeptide 1B1 [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Human organic anion transporting polypeptide (OATP) 1B1 and 1B3 are two highly homologous liver-specific uptake transporters. However, 2’,7’-dichlorofluorescein (DCF) is preferably transported by OATP1B1. In the present study, the molecular mechanisms for the selective transport of DCF by OATP1B1 were investigated by constructing and characterizing an array of OATP1B1/1B3 chimeras and site-directed mutagenesis. Our results show that transmembrane domain (TM) 10 is crucial for the surface expression and function of OATP1B1, in which Q541 and L545 play the most important roles in DCF transport. Replacement of TM10 in OATP1B1 with its OATP1B3 counterpart led to OATP1B1’s complete intracellular retention. Q541 and L545 may interact with DCF directly via hydrogen bonding and hydrophobic interactions. The decrease of DCF uptake by Q541A and L545S was due to their reduced binding affinity for DCF as compared with OATP1B1. In addition, Q541 and L545 are also crucial for the transport of estradiol-17β-glucuronide (E17βG) but not for the transport of estrone-3-sulfate (E3S), indicating different interaction modes between DCF/E17βG and E3S in OATP1B1. Taken together, Q541 and L545 in TM10 are critical for OATP1B1-mediated DCF uptake, but their effect is substrate-dependent. SIGNIFICANCE STATEMENT The key TMs and amino acid residues for the selective transport of DCF by OATP1B1 were identified. TM10 is crucial for the surface expression and function of OATP1B1. Within TM10, Q541 and L545 played the most significant roles and affected the function of OATP1B1 in a substrate-dependent manner. This information is crucial for a better understanding of the mechanism of the multispecificity of OATP1B1 and as a consequence the mechanism of OATP1B1-mediated drug–drug interactions. Full Article
b Investigations into the Concentrations and Metabolite Profiles of Doping Agents and Antidepressants in Human Seminal Fluid Using Liquid Chromatography-Mass Spectrometry [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Exogenous substances, including drugs and chemicals, can transfer into human seminal fluid and influence male fertility and reproduction. In addition, substances relevant in the context of sports drug testing programs, can be transferred into the urine of a female athlete (after unprotected sexual intercourse) and trigger a so-called adverse analytical finding. Here, the question arises as to whether it is possible to distinguish analytically between intentional doping offenses and unintentional contamination of urine by seminal fluid. To this end, 480 seminal fluids from nonathletes were analyzed to identify concentration ranges and metabolite profiles of therapeutic drugs that are also classified as doping agents. Therefore, a screening procedure was developed using liquid chromatography connected to a triple quadrupole mass spectrometer, and suspect samples (i.e., samples indicating the presence of relevant compounds) were further subjected to liquid chromatography-high-resolution accurate mass (tandem) mass spectrometry. The screening method yielded 90 findings (including aromatase inhibitors, selective estrogen receptor modulators, diuretics, stimulants, glucocorticoids, beta-blockers, antidepressants, and the nonapproved proliferator-activated receptor delta agonist GW1516) in a total of 81 samples, with 91% of these suspected cases being verified by the confirmation method. In addition to the intact drug, phase-I and -II metabolites were also occasionally observed in the seminal fluid. This study demonstrated that various drugs including those categorized as doping agents partition into seminal fluid. Monitoring substances and metabolites may contribute to a better understanding of the distribution and metabolism of exogenous substances in seminal fluid that may be responsible for the impairment of male fertility. SIGNIFICANCE STATEMENT This study demonstrates that doping agents as well as clinically relevant substances are transferred/eliminated into seminal fluid to a substantial extent and that knowledge about drug levels (and potential consequences for the male fertility and female exposure) is limited. The herein generated new dataset provides new insights into an important and yet little explored area of drug deposition and elimination, and hereby a basis for the assessment of contamination cases by seminal fluid in sports drug testing. Full Article
b Effects of Compound Probiotics on Pharmacokinetics of Cytochrome 450 Probe Drugs in Rats [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Compound probiotics have been widely used and commonly coadministered with other drugs for treating various chronic illnesses, yet their effects on drug pharmacokinetics remain underexplored. This study elucidated the impact of VSL#3 on the metabolism of probe drugs for cytochrome P450 enzymes (P450s), specifically omeprazole, tolbutamide, midazolam, metoprolol, phenacetin, and chlorzoxazone. Male Wistar rats were administered drinking water containing VSL#3 or not for 14 days and then intragastrically administered a P450 probe cocktail; this was done to investigate the host P450’s metabolic phenotype. Stool, liver/jejunum, and serum samples were collected for 16S ribosomal RNA sequencing, RNA sequencing, and bile acid profiling. The results indicated significant differences in both α and β diversity of intestinal microbial composition between the probiotic and vehicle groups in rats. In the probiotic group, the bioavailability of omeprazole increased by 269.9%, whereas those of tolbutamide and chlorpropamide decreased by 28.1% and 27.4%, respectively. The liver and jejunum exhibited 1417 and 4004 differentially expressed genes, respectively, between the two groups. In the probiotic group, most of P450 genes were upregulated in the liver but downregulated in the jejunum. The expression of genes encoding metabolic enzymes and drug transporters also changed. The serum-conjugated bile acids in the probiotic group were significantly reduced. Shorter duodenal villi and longer ileal villi were found in the probiotic group. In summary, VSL#3 administration altered the gut microbiota, host drug–processing gene expression, and intestinal structure in rats, which could be reasons for pharmacokinetic changes. SIGNIFICANCE STATEMENT This study focused on the effects of the probiotic VSL#3 on the pharmacokinetic profile of cytochrome P450 probe drugs and the expression of host drug metabolism genes. Compared with previous studies, the present study provides a comprehensive explanation for the host drug metabolism profile modified by probiotics, combined here with the bile acid profile and histopathological analysis. Full Article
b The Simultaneous Inhibition of Solute Carrier Family 6 Member 19 and Breast Cancer Resistance Protein Transporters Leads to an Increase of Indoxyl Sulfate (a Uremic Toxin) in Plasma and Kidney [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Solute carrier family 6 member 19 (SLC6A19) inhibitors are being studied as therapeutic agents for phenylketonuria. In this work, a potent SLC6A19 inhibitor (RA836) elevated rat kidney uremic toxin indoxyl sulfate (IDS) levels by intensity (arbitrary unit) of 13.7 ± 7.7 compared with vehicle 0.3 ± 0.1 (P = 0.01) as determined by tissue mass spectrometry imaging analysis. We hypothesized that increased plasma and kidney levels of IDS could be caused by the simultaneous inhibition of both Slc6a19 and a kidney IDS transporter responsible for excretion of IDS into urine. To test this, we first confirmed the formation of IDS through tryptophan metabolism by feeding rats a Trp-free diet. Inhibiting Slc6a19 with RA836 led to increased IDS in these rats. Next, RA836 and its key metabolites were evaluated in vitro for inhibiting kidney transporters such as organic anion transporter (OAT)1, OAT3, and breast cancer resistance protein (BCRP). RA836 inhibits BCRP with an IC50 of 0.045 μM but shows no significant inhibition of OAT1 or OAT3. Finally, RA836 analogs with either potent or no inhibition of SLC6A19 and/or BCRP were synthesized and administered to rats fed a normal diet. Plasma and kidney samples were collected to quantify IDS using liquid chromatography–mass spectrometry. Neither a SLC6A19 inactive but potent BCRP inhibitor nor a SLC6A19 active but weak BCRP inhibitor raised IDS levels, whereas compounds inhibiting both transporters caused IDS accumulation in rat plasma and kidney, supporting the hypothesis that rat Bcrp contributes to the excretion of IDS. In summary, we identified that inhibiting Slc6a19 increases IDS formation, while simultaneously inhibiting Bcrp results in IDS accumulation in the kidney and plasma. SIGNIFICANCE STATEMENT This is the first publication to decipher the mechanism for accumulation of indoxyl sulfate (IDS) (a uremic toxin) in rats via inhibition of both Slc6a19 and Bcrp. Specifically, inhibition of Slc6a19 in the gastrointestinal track increases IDS formation, and inhibition of Bcrp in the kidney blocks IDS excretion. Therefore, we should avoid inhibiting both solute carrier family 6 member 19 and breast cancer resistance protein simultaneously in humans to prevent accumulation of IDS, a known risk factor for cardiovascular disease, psychic anxiety, and mortality in chronic kidney disease patients. Full Article
b Quantitatively Predicting Effects of Exercise on Pharmacokinetics of Drugs Using a Physiologically Based Pharmacokinetic Model [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Exercise significantly alters human physiological functions, such as increasing cardiac output and muscle blood flow and decreasing glomerular filtration rate (GFR) and liver blood flow, thereby altering the absorption, distribution, metabolism, and excretion of drugs. In this study, we aimed to establish a database of human physiological parameters during exercise and to construct equations for the relationship between changes in each physiological parameter and exercise intensity, including cardiac output, organ blood flow (e.g., muscle blood flow and kidney blood flow), oxygen uptake, plasma pH and GFR, etc. The polynomial equation P = aiHRi was used for illustrating the relationship between the physiological parameters (P) and heart rate (HR), which served as an index of exercise intensity. The pharmacokinetics of midazolam, quinidine, digoxin, and lidocaine during exercise were predicted by a whole-body physiologically based pharmacokinetic (WB-PBPK) model and the developed database of physiological parameters following administration to 100 virtual subjects. The WB-PBPK model simulation results showed that most of the observed plasma drug concentrations fell within the 5th–95th percentiles of the simulations, and the estimated peak concentrations (Cmax) and area under the curve (AUC) of drugs were also within 0.5–2.0 folds of observations. Sensitivity analysis showed that exercise intensity, exercise duration, medication time, and alterations in physiological parameters significantly affected drug pharmacokinetics and the net effect depending on drug characteristics and exercise conditions. In conclusion, the pharmacokinetics of drugs during exercise could be quantitatively predicted using the developed WB-PBPK model and database of physiological parameters. SIGNIFICANCE STATEMENT This study simulated real-time changes of human physiological parameters during exercise in the WB-PBPK model and comprehensively investigated pharmacokinetic changes during exercise following oral and intravenous administration. Furthermore, the factors affecting pharmacokinetics during exercise were also revealed. Full Article