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Targeted and complete genomic sequencing of the major histocompatibility complex in haplotypic form of individual heterozygous samples [RESEARCH]

The human major histocompatibility complex (MHC) is a ~4 Mb genomic segment on Chromosome 6 that plays a pivotal role in the immune response. Despite its importance in various traits and diseases, its complex nature makes it challenging to accurately characterize on a routine basis. We present a novel approach allowing targeted sequencing and de novo haplotypic assembly of the MHC region in heterozygous samples, using long-read sequencing technologies. Our approach is validated using two reference samples, two family trios, and an African-American sample. We achieved excellent coverage (96.6%–99.9% with at least 30x depth) and high accuracy (99.89%–99.99%) for the different haplotypes. This methodology offers a reliable and cost-effective method for sequencing and fully characterizing the MHC without the need for whole-genome sequencing, facilitating broader studies on this important genomic segment and having significant implications in immunology, genetics, and medicine.




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Impact of COVID-19 on Chronic Ambulatory-Care-Sensitive Condition Emergency Department Use Among Older Adults

Background:

The COVID-19 pandemic social distancing requirements encouraged patients to avoid public spaces including in-office health care visits. Ambulatory-care-sensitive conditions (ACSCs) represent conditions that can be managed with quality primary care and when access is limited, these conditions can lead to avoidable emergency department (ED) visits.

Methods:

Using national data on ED visits from 2019 to 2021 in the National Hospital Ambulatory Care Survey, we examined the impact of COVID-19 pandemic on ACSC ED visits among older adults (aged ≥65).

Results:

The proportion of ED visits among older adults that were for ACSCs increased between 2019 (17.4%) and 2021 (18.5%). The trend in both rural (26.4%–28.6%) and urban areas (15.4%–16.8%) shows a significant jump from 2019 to 2021 (P < .001).

Conclusions:

This rise in ACSC ED use is consistent with a delay in normal primary care during the pandemic.




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Impact of Point of Care Hemoglobin A1c Testing on Time to Therapeutic Intervention

Without compromising accuracy, point of care testing (POCT) provides immediate results at the time of in person patient consultation. The purpose of this study was to evaluate time until therapeutic intervention with POCT HbA1c versus venipuncture, where venipuncture was considered standard of care.

The primary outcome was time (hours) to implementation of a therapeutic intervention based on POCT HbA1c result, as compared with most recent venipuncture HbA1c before the study and its associated therapeutic intervention. A total of 94 POCT HbA1c tests were included in the primary analysis.

For the POCT HbA1c, the mean time to therapeutic intervention was 1.6 ± 3.14 hours. For the previous venipuncture HbA1c, the mean time to therapeutic intervention was 1376.66 ± 3356.6 hours (P < .001). Overall, this trial showed that POCT HbA1c results in a significantly faster time to therapeutic intervention than venipuncture in a primary care clinic that serves a rural population.




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A Comprehensive Guide to Long-Acting Injectable Antipsychotics for Primary Care Clinicians

We propose a paper that provides education on commonly used long-acting injectable antipsychotics (LAIs) to improve primary care based mental health interventions in patients with severe mental illnesses (SMIs) such as schizophrenia, schizoaffective disorder, and bipolar disorders. With the expanding interface of primary care and psychiatry across all healthcare settings, it has become increasingly important for primary care clinicians to have a broader understanding of common psychiatric treatments, including LAIs. Long-acting injectable antipsychotics have been shown to be helpful in significantly improving treatment adherence, preventing disease progression, improving treatment response, decreasing readmission rates, and reducing social impairment. We discuss evidence-based indications and guidelines for use of long-acting injectable antipsychotics. We provide an overview of the treatment of SMI with LAIs, mainly focusing on the most commonly used long-acting injectable antipsychotics, advantages and disadvantages of each, along with outlining important clinical pearls for ease of practical application. Equipped with increased familiarity and understanding of these essential therapies, primary care clinicians can better facilitate early engagement with psychiatric care, promote more widespread use, and thus significantly improve the wellbeing and quality of life of patients with severe mental illness.




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Clinician-Reported Barriers and Needs for Implementation of Continuous Glucose Monitoring

Background:

Continuous glucose monitoring (CGM) for patients with type 1 and type 2 diabetes is associated with improved clinical, behavioral, and psychosocial patient health outcomes and is part of the American Diabetes Association’s Standards of Medical Care. CGM prescription often takes place in endocrinology practices, yet 50% of adults with type 1 diabetes and 90% of all people with type 2 diabetes receive their diabetes care in primary care settings. This study examined primary care clinicians’ perceptions of barriers and resources needed to support CGM use in primary care.

Methods:

This qualitative study used semistructured interviews with primary care clinicians to understand barriers to CGM and resources needed to prescribe. Participants were recruited through practice-based research networks. Rapid qualitative analysis was used to summarize themes from interview findings.

Results:

We conducted interviews with 55 primary care clinicians across 21 states. Participants described CGM benefits for patients with varying levels of diabetes self-management and engagement. Major barriers to prescribing included lack of insurance coverage for CGM costs to patients, and time constraints. Participants identified resources needed to foster CGM prescribing, for example, clinician education, support staff, and EHR compatibility.

Conclusion:

Primary care clinicians face several challenges to prescribing CGM, but they are interested in learning more to help them offer it to their patients. This study reinforces the ongoing need for improved clinician education on CGM technology and continued expansion of insurance coverage for people with both type 1 and type 2 diabetes.




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Colorectal Cancer Screening: A Multicomponent Intervention to Increase Uptake in Patients Aged 45-49

Purpose:

Colorectal cancer (CRC) screening is recommended starting at age 45, but there has been little research on strategies to promote screening among patients younger than 50. This study assessed the effect of a multicomponent intervention on screening completion in this age group.

Methods:

The intervention consisted of outreach to patients aged 45 to 49 (n = 3,873) via mailed fecal immunochemical test (FIT) (sent to 46%), text (84%), e-mail (53%), and the extension to this age group of an existing standing order protocol allowing primary care nurses and medical assistants to order FIT at primary care clinics in an urban safety-net system. We used segmented linear regression to assess changes in CRC screening completion trends. Patients aged 51 to 55 were included as a comparison group (n = 3,943). Data were extracted from the EHR.

Results:

The percentage of patients aged 45 to 49 who were up-to-date with CRC screening (colonoscopy in 10 years or FIT in last year) increased an average of 0.4% (95% CI 0.3, 0.6)) every 30 days before intervention rollout and 2.8% (95% CI 2.5, 3.1) after (slope difference 2.3% [95% CI 2.0, 2.7]). This difference persisted after accounting for small changes in the outcome observed in the comparison group (slope difference 1.7% [95% CI 1.2, 2.2]).

Conclusions:

These results suggest that the intervention increased CRC screening completion among patients 45 to 49. Health care systems seeking to improve CRC screening participation among patients aged 45 to 49 should consider implementing similar interventions.




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Implementation of an Opt-Out Outpatient HIV Screening Program

Background:

Screening rates for Human Immunodeficiency Virus (HIV) remain low despite guidelines by both the CDC and USPSTF recommending that all adolescents and adults be screened at least once. The aim of this quality improvement study was to increase HIV screening among eligible patients.

Methods:

This quality improvement study assessed the impact of interventions to increase HIV screening in an outpatient population at a large urban safety-net hospital. Outcomes were compared from the preintervention (December 2020 to November 2021) to postintervention years (December 2021 to November 2022). Stepwise electronic alerts to prompt HIV screening paired with provider financial incentives were implemented. The proportion of eligible individuals screened for HIV were compared after intervention implementation.

Results:

Average monthly HIV screening increased from 506 ± 97 to 2484 ± 663 between the pre- and postintervention periods, correlating to a 5.1-fold increase in screening (7.8% to 39.8%, P < .01). Increases were seen across all ages, and those aged 55 to 64 and 65+ had the highest relative increase in screening at 7.5 and 9.3-fold, respectively (P < .01). Screening rates increased for Hispanics (7.9% preintervention vs 43.6% postintervention, P < .01). In the pre- and postintervention periods, 41 patients with new HIV diagnoses were identified (13 preintervention and 28 postintervention) and 85.4% were linked to care within 30 days.

Conclusions:

Stepwise interventions targeted at primary care clinicians are an effective way to increase HIV screening rates, particularly in older demographics. Earlier HIV diagnosis coupled with linkage to care is an important strategy in ending the HIV epidemic.




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A Qualitative Analysis of a Primary Care Medical-Legal Partnership: Impact, Barriers, and Facilitators

Background:

Certain health-related risk factors require legal interventions. Medical-legal partnerships (MLPs) are collaborations between clinics and lawyers that address these health-harming legal needs (HHLNs) and have been shown to improve health and reduce utilization.

Objective:

The objective of this study is to explore the impact, barriers, and facilitators of MLP implementation in primary care clinics.

Methods:

A qualitative design using a semistructured interview assessed the perceived impact, barriers, and facilitators of an MLP, among clinicians, clinic and MLP staff, and clinic patients. Open AI software (otter.ai) was used to transcribe interviews, and NVivo was used to code the data. Braun & Clarke’s framework was used to identify themes and subthemes.

Results:

Sixteen (n = 16) participants were included in this study. Most respondents were women (81%) and white (56%). Four respondents were clinic staff, and 4 were MLP staff while 8 were clinic patients. Several primary themes emerged including: Patients experienced legal issues that were pernicious, pervasive, and complex; through trusting relationships, the MLP was able to improve health and resolve legal issues, for some; mistrust, communication gaps, and inconsistent staffing limited the impact of the MLP; and, the MLP identified coordination and communication strategies to enhance trust and amplify its impact.

Conclusion:

HHLNs can have a significant, negative impact on the physical and mental health of patients. Respondents perceived that MLPs improved health and resolved these needs, for some. Despite perceived successes, integration between the clinical and legal organizations was elusive.




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Reply to Letter to Editor Concerning &#x201C;Nocturnal Pressure Controlled Ventilation Improves Sleep Efficiency in Patients Receiving Mechanical Ventilation&#x201D;




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The Evolution of Intermittent Mandatory Ventilation: Update and Implications for Home Care




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Comparing Highs and Flows in Patients With COPD With Chronic Hypercapnic Respiratory Failure




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The Challenge of Implementing Race-Neutral PFT Reference Equations




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Downstream Effects of Market Changes on Inhalers: Impacts on Individuals With Chronic Lung Disease

COPD and asthma are two of the most common chronic lung diseases, affecting over 545 million people globally and 34 million in the United States. Annual health care costs related to chronic lung disease are estimated at €380 billion in the European Union, and $24–$50 billion in the United States averaging to $4,000 in out-of-pocket costs per person in the U.S. A full-text literature search was conducted for English publications between January 1, 2005–March 18, 2024. It returned over 5,000 publications that were further narrowed using key search words, resulting in 172 peer-reviewed articles. Using their experience and subject expertise, the authors further narrowed the peer-reviewed articles to 55 that were in their opinion relevant. Also, 38 recently published industry reports and news articles specific to downstream effects of inhaler market changes and the future impact were included. The literature suggests that individuals with chronic lung disease face increased challenges with access to inhaled medication due to rising medication costs, discontinuation of branded medications, introduction of generic medications not covered by insurance, exclusionary preferred drug list tactics that force health care providers into non-medical switching of medication or devices, and ongoing medication shortages. Providers experience ongoing hurdles in prescribing appropriate inhaled medications for individuals with chronic lung disease, including increased time and costs spent on administrative tasks due to inhaler denials, a loss of patient trust, and limits on their ability to prescribe appropriate inhaled medication for individuals with chronic lung disease.




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Exploring the Impact of Varied Design Approaches and Materials in Respiratory Therapy Education




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The Impact of Opioid Prescription on the Occurrence and Outcome of Pneumonia: A Nationwide Cohort Study in South Korea

BACKGROUND:Opioids are known to cause respiratory depression, aspiration, and to suppress the immune system. This study aimed to investigate the relationship between short- and long-term opioid use and the occurrence and clinical outcomes of pneumonia in South Korea.METHODS:The data for this population-based retrospective cohort analysis were obtained from the South Korean National Health Insurance Service. The opioid user group consisted of those prescribed opioids in 2016, while the non-user group, who did not receive opioid prescriptions that year, was selected using a 1:1 stratified random sampling method. The opioid users were categorized into short-term (1–89 d) and long-term (≥90 d) users. The primary end point was pneumonia incidence from January 1, 2017–December 31, 2021, with secondary end points including pneumonia-related hospitalizations and mortality rates during the study period.RESULTS:In total, 4,556,606 adults were enrolled (opioid group, 2,070,039). Opioid users had a 3% higher risk of pneumonia and an 11% higher risk of pneumonia requiring hospitalization compared to non-users. Short-term users had a 3% higher risk of pneumonia, and long-term users had a 4% higher risk compared to non-users (P < .001). Additionally, short-term users had an 8% higher risk of hospital-treated pneumonia, and long-term users had a 17% higher risk compared to non-users (P < .001).CONCLUSIONS:Both short- and long-term opioid prescriptions were associated with higher incidences of pneumonia and hospital-treated pneumonia. In addition, long-term opioid prescriptions were linked to higher mortality rates due to pneumonia.




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Effect of Fasting Prior to Extubation on Prevalence of Empty Stomach in Enterally Fed and Mechanically Ventilated Patients

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%.




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The Impact of Increased PEEP on Hemodynamics, Respiratory Mechanics, and Oxygenation in Pediatric ARDS

BACKGROUND:PEEP is a cornerstone treatment for children with pediatric ARDS. Unfortunately, its titration is often performed solely by evaluating oxygen saturation, which can lead to inadequate PEEP level settings and consequent adverse effects. This study aimed to assess the impact of increasing PEEP on hemodynamics, respiratory system mechanics, and oxygenation in children with ARDS.METHODS:Children receiving mechanical ventilation and on pressure-controlled volume-guaranteed mode were prospectively assessed for inclusion. PEEP was sequentially changed to 5, 12, 10, 8 cm H2O, and again to 5 cm H2O. After 10 min at each PEEP level, hemodynamic, ventilatory, and oxygenation variables were collected.RESULTS:A total of 31 subjects were included, with median age and weight of 6 months and 6.3 kg, respectively. The main reasons for pediatric ICU admission were respiratory failure caused by acute viral bronchiolitis (45%) and community-acquired pneumonia (32%). Most subjects had mild or moderate ARDS (45% and 42%, respectively), with a median (interquartile range) oxygenation index of 8.4 (5.8–12.7). Oxygen saturation improved significantly when PEEP was increased. However, although no significant changes in blood pressure were observed, the median cardiac index at PEEP of 12 cm H2O was significantly lower than that observed at any other PEEP level (P = .001). Fourteen participants (45%) experienced a reduction in cardiac index of > 10% when PEEP was increased to 12 cm H2O. Also, the estimated oxygen delivery was significantly lower, at 12 cm H2O PEEP. Finally, respiratory system compliance significantly reduced when PEEP was increased. At a PEEP of 12 cm H2O, static compliance had a median reduction of 25% in relation to the initial assessment (PEEP of 5 cm H2O).CONCLUSIONS:Although it may improve arterial oxygen saturation, inappropriately high PEEP levels may reduce cardiac output, oxygen delivery, and respiratory system compliance in pediatric subjects with ARDS with low potential for lung recruitability.




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Quantitative Computed Tomography and Response to Pronation in COVID-19 ARDS

BACKGROUND:The use of prone position (PP) has been widespread during the COVID-19 pandemic. Whereas it has demonstrated benefits, including improved oxygenation and lung aeration, the factors influencing the response in terms of gas exchange to PP remain unclear. In particular, the association between baseline quantitative computed tomography (CT) scan results and gas exchange response to PP in invasively ventilated subjects with COVID-19 ARDS is unknown. The present study aimed to compare baseline quantitative CT results between subjects responding to PP in terms of oxygenation or CO2 clearance and those who did not.METHODS:This was a single-center, retrospective observational study including critically ill, invasively ventilated subjects with COVID-19–related ARDS admitted to the ICUs of Niguarda Hospital between March 2020–November 2021. Blood gas samples were collected before and after PP. Subjects in whom the PaO2/FIO2 increase was ≥ 20 mm Hg after PP were defined as oxygen responders. CO2 responders were defined when the ventilatory ratio (VR) decreased during PP. Automated quantitative CT analyses were performed to obtain tissue mass and density of the lungs.RESULTS:One hundred twenty-five subjects were enrolled, of which 116 (93%) were O2 responders and 51 (41%) CO2 responders. No difference in quantitative CT characteristics and oxygen were observed between responders and non-responders (tissue mass 1,532 ± 396 g vs 1,654 ± 304 g, P = .28; density −544 ± 109 HU vs −562 ± 58 HU P = .42). Similar findings were observed when dividing the population according to CO2 response (tissue mass 1,551 ± 412 g vs 1,534 ± 377 g, P = .89; density −545 ± 123 HU vs −546 ± 94 HU, P = .99).CONCLUSIONS:Most subjects with COVID-19–related ARDS improved their oxygenation at the first pronation cycle. The study suggests that baseline quantitative CT scan data were not associated with the response to PP in oxygenation or CO2 in mechanically ventilated subjects with COVID-19–related ARDS.




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Rehabilitation Is Associated With Improvements in Post-COVID-19 Sequelae

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.




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Comparison of Web-Based and On-Site Lung Simulators for Education in Mechanical Ventilation

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.




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Editor&#x2019;s Commentary




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Intraprofessional Education Experiences in Dentistry: Dental hygienists&#x2019; perceptions of collaboration with dentists

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.




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Comparison of Needle Depth Techniques for the Posterior Superior Alveolar Block

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.




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Improving Patient Outcomes through the Diagnostic and Care Planning Process




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A Strategic Guide to Improve and De-Risk Vaccine Development: CEPIs CMC Framework

The Coalition for Epidemic Preparedness Innovations (CEPI) has developed a robust CMC (Chemistry, Manufacturing, and Controls) Framework to enhance the likelihood of successful vaccine development. This Framework serves as a comprehensive guide, aiding developers in building effective strategies to overcome the challenges posed by the different phases of vaccine development, including the ones often referred to as the "valleys of death". The Framework lists stage-appropriate deliverables, categorized and refined, spanning five key areas: manufacturing process, formulation and stability, analytics, supply chain, and compliance. By emphasizing the critical aspects of CMC development, CEPI's objective is to expedite the progression of vaccine candidates from research to deployment, reducing delays, mitigating risks, and optimizing the overall development process, all while upholding uncompromising quality standards, ultimately increasing the probability of success.




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Impact of Dimensional Variability of Primary Packaging Materials on the Break-Loose and Gliding Forces of Prefilled Syringes

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.




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Comparison of Binary Alcohol/Water Solvent Systems to Blood for Extractions of Blood-Contacting Medical Devices

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.




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Development and Validation of a Customized Amplex UltraRed Assay for Sensitive Hydrogen Peroxide Detection in Pharmaceutical Water

For clean-room technologies such as isolators and restricted access barrier systems (RABS), decontamination using hydrogen peroxide (H2O2) is increasingly attractive to fulfill regulatory requirements. Several approaches are currently used, ranging from manual wipe disinfection to vapor phase hydrogen peroxide (VPHP) or automated nebulization sanitization. Although the residual airborne H2O2 concentration can be easily monitored, detection of trace H2O2 residues in filled products is rather challenging. To simulate the filling process in a specific clean room, technical runs with water for injection (WfI) are popular. Thus, the ability to detect traces of H2O2 in water is an important prerequisite to ensure a safe and reliable use of H2O2 for isolator or clean room decontamination. The objective of this study was to provide a validated quantitative, fluorometric Amplex UltraRed assay, which satisfies the analytical target profile of quantifying H2O2 in WfI at low nanomolar to low micromolar concentrations (ppb range) with high accuracy and high precision. The Amplex UltraRed technology provides a solid basis for this purpose; however, no commercial assay kit that fulfills these requirements is available. Therefore, a customized Amplex UltraRed assay was developed, optimized, and validated. This approach resulted in an assay that is capable of quantifying H2O2 in WfI selectively, sensitively, accurately, precisely, and robustly. This assay is used in process development and qualification approaches using WfI in H2O2-decontaminated clean rooms and isolators.




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YY1 knockout in pro-B cells impairs lineage commitment, enabling unusual hematopoietic lineage plasticity [Research Papers]

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.




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A germline PAF1 paralog complex ensures cell type-specific gene expression [Research Papers]

Animal germline development and fertility rely on paralogs of general transcription factors that recruit RNA polymerase II to ensure cell type-specific gene expression. It remains unclear whether gene expression processes downstream from such paralog-based transcription is distinct from that of canonical RNA polymerase II genes. In Drosophila, the testis-specific TBP-associated factors (tTAFs) activate over a thousand spermatocyte-specific gene promoters to enable meiosis and germ cell differentiation. Here, we show that efficient termination of tTAF-activated transcription relies on testis-specific paralogs of canonical polymerase-associated factor 1 complex (PAF1C) proteins, which form a testis-specific PAF1C (tPAF). Consequently, tPAF mutants show aberrant expression of hundreds of downstream genes due to read-in transcription. Furthermore, tPAF facilitates expression of Y-linked male fertility factor genes and thus serves to maintain spermatocyte-specific gene expression. Consistently, tPAF is required for the segregation of meiotic chromosomes and male fertility. Supported by comparative in vivo protein interaction assays, we provide a mechanistic model for the functional divergence of tPAF and the PAF1C and identify transcription termination as a developmentally regulated process required for germline-specific gene expression.




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Harnessing brain-body communication to understand cancer [Special Section: Symposium Outlook]

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.




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Temperature matters: the potential impact of thermoregulatory mechanisms in brain-body physiology [Special Section: Symposium Outlook]

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.




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Bridging brain and body in cancer [Special Section: Symposium Outlook]

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.




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Interoceptive inference and prediction in food-related disorders [Special Section: Symposium Outlook]

The brain's capacity to predict and anticipate changes in internal and external environments is fundamental to initiating efficient adaptive responses, behaviors, and reflexes that minimize disruptions to physiology. In the context of feeding control, the brain predicts and anticipates responses to the consumption of dietary substances, thus driving adaptive behaviors in the form of food choices, physiological preparation for meals, and engagement of defensive mechanisms. Here, we provide an integrative perspective on the multisensory computation between exteroceptive and interoceptive cues that guides feeding strategy and may result in food-related disorders.




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Consolidating roles of neuroimmune reflexes: specificity of afferent, central, and efferent signals in homeostatic immune networks [Special Section: Symposium Outlook]

Neural reflexes occupy a central role in physiological homeostasis. The vagus nerve is a major conduit for transmitting afferent and efferent signals in homeostatic reflex arcs between the body and the brain. Recent advances in neuroscience, immunology, and physiology have revealed important vagus nerve mechanisms in suppressing inflammation and treating rheumatoid arthritis and other autoimmune conditions. Numerous clinical trials indicate that there is significant benefit to vagus nerve stimulation therapy. Although many questions are still unanswered, it will be important, even necessary, to pursue answers that will be useful in guiding interventions to modulate immunological and physiological homeostasis.




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What a wonderful world! [Special Section: Symposium Outlook]

The world of cancer science is moving toward a paradigm shift in making connections with neuroscience. After decades of research on genetic instability and mutations or on the tumor microenvironment, emerging evidence suggests that a malignant tumor is able to hijack and use the brain and its network of peripheral and central neurons as disrupters of homeostasis in the body. Whole-body homeostasis requires brain–body circuits to maintain survival and health via the processes of interoception, immunoception, and nociception. It is now likely that cancer disturbs physiological brain–body communication in making bidirectional brain tumor connections.




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Deciphering visceral instincts: a scientific quest to unravel food choices from molecules to mind [Special Section: Symposium Outlook]

The study of biological mechanisms, while crucial, cannot fully explain complex phenomena like the instinct to eat. The mind–body connection, as exemplified by the concept of "voodoo death," highlights the profound influence of belief and cultural context on physiology. Indigenous knowledge systems further emphasize the interconnectedness of humans with their environment. Recent discoveries in gut–brain communication reveal the intricate neural circuits that drive our visceral desires, but a holistic approach that integrates both physiological mechanisms and the subjective experience of life, informed by diverse cultural perspectives, will be essential to truly understand what it means to be alive.




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The area postrema: a critical mediator of brain-body interactions [Special Section: Symposium Outlook]

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.




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Cancer neuroscience at the brain-body interface [Special Section: Symposium Outlook]

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.




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Dysregulating mTORC1-4E-BP2 signaling in GABAergic interneurons impairs hippocampus-dependent learning and memory [RESEARCH PAPERS]

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.




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Characterization and implementation of the MarathonRT template-switching reaction to expand the capabilities of RNA-seq [ARTICLE]

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.




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The antivirulent Staphylococcal sRNA SprC regulates CzrB efflux pump to adapt its response to zinc toxicity [ARTICLE]

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.




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Abolished frameshifting for predicted structure-stabilizing SARS-CoV-2 mutants: implications to alternative conformations and their statistical structural analyses [ARTICLE]

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.




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Improved functions for nonlinear sequence comparison using SEEKR [ARTICLE]

SEquence Evaluation through k-mer Representation (SEEKR) is a method of sequence comparison that uses sequence substrings called k-mers to quantify the nonlinear similarity between nucleic acid species. We describe the development of new functions within SEEKR that enable end-users to estimate P-values that ascribe statistical significance to SEEKR-derived similarities, as well as visualize different aspects of k-mer similarity. We apply the new functions to identify chromatin-enriched lncRNAs that contain XIST-like sequence features, and we demonstrate the utility of applying SEEKR on lncRNA fragments to identify potential RNA-protein interaction domains. We also highlight ways in which SEEKR can be applied to augment studies of lncRNA conservation, and we outline the best practice of visualizing RNA-seq read density to evaluate support for lncRNA annotations before their in-depth study in cell types of interest.




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Could cough hypersensitivity symptom profile differentiate phenotypes of chronic cough?

Background

Recently, cough reflex hypersensitivity has been proposed as a common underlying feature of chronic cough in adults. However, symptoms and clinical characteristics of cough hypersensitivity have not been studied amongst phenotypes of chronic cough. This study aimed to compare symptom features, such as cough triggers and associated throat sensations, of cough hypersensitivity in patients with asthmatic chronic cough and those with refractory chronic cough (RCC).

Methods

Patients with chronic cough from the Korean Chronic Cough Registry were prospectively evaluated over 6 months. Physicians determined the aetiological diagnosis based on clinical evaluations and responses to treatment at the 6-month follow-up visit. Symptoms of cough hypersensitivity and cough-specific quality of life were assessed using the Cough Hypersensitivity Questionnaire (CHQ) and the Leicester Cough Questionnaire (LCQ), respectively.

Results

The analysis included 280 patients who completed the follow-up: 79 with asthmatic cough (cough variant asthma or eosinophilic bronchitis) and 201 with RCC. Baseline CHQ scores were similar between the groups (8.3±3.7 in asthmatic cough versus 8.9±3.9 in RCC; p=0.215, adjusted for age, sex and LCQ score). There were no significant between-group differences in the LCQ and cough severity Visual Analog Scale scores. Both groups showed a similar negative correlation with LCQ scores (asthmatic cough: r=–0.427, p<0.001; RCC: r=–0.306, p<0.001).

Conclusions

The symptoms of cough hypersensitivity may not distinguish between asthmatic cough and RCC. This suggests that chronic cough is the primary diagnosis in both phenotypes. It indicates a shared mechanism in their cough pathogenesis, despite having potentially different treatable traits.




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Accuracy of CAD4TB (Computer-Aided Detection for Tuberculosis) on paediatric chest radiographs

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.




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Effects of Compound Probiotics on Pharmacokinetics of Cytochrome 450 Probe Drugs in Rats [Articles]

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.




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Comparison of the CYP3A Selective Inhibitors CYP3cide, Clobetasol, and Azamulin for Their Potential to Distinguish CYP3A7 Activity in the Presence of CYP3A4/5 [Articles]

The CYP3A7 enzyme accounts for ~50% of the total cytochrome P450 (P450) content in fetal and neonatal livers and is the predominant P450 involved in neonatal xenobiotic metabolism. Additionally, it is a key player in healthy birth outcomes through the oxidation of dehydroepiandrosterone (DHEA) and DHEA-sulfate. The amount of the other hepatic CYP3A isoforms, CYP3A4 and CYP3A5, expressed in neonates is low but highly variable, and therefore the activity of individual CYP3A isoforms is difficult to differentiate due to their functional similarities. Consequently, a better understanding of the contribution of CYP3A7 to drug metabolism is essential to identify the risk that drugs may pose to neonates and developing infants. To distinguish CYP3A7 activity from CYP3A4/5, we sought to further characterize the selectivity of the specific CYP3A inhibitors CYP3cide, clobetasol, and azamulin. We used three substrate probes, dibenzylfluorescein, luciferin-PPXE, and midazolam, to determine the IC50 and metabolism-dependent inhibition (MDI) properties of the CYP3A inhibitors. Probe selection had a significant effect on the IC50 values and P450 inactivation across all inhibitory compounds and enzymes. CYP3cide and azamulin were both identified as MDIs and were most specific for CYP3A4. Contrary to previous reports, we found that clobetasol propionate (CP) was not an MDI of CYP3A5 but was more selective for CYP3A5 over CYP3A4/7. We further investigated CYP3cide and CP’s ability to differentiate CYP3A7 activity in an equal mixture of recombinant CYP3A4, CYP3A5, and CYP3A7, and our results provide confidence of CYP3cide’s and CP’s ability to distinguish CYP3A7 activity in the presence of the other CYP3A isoforms.

SIGNIFICANCE STATEMENT

These findings provide valuable insight regarding in vitro testing conditions to investigate the metabolism of new drug candidates and help determine drug safety in neonates. The results presented here also clearly demonstrate the effect that probe selection may have on CYP3A cytochrome P450 inhibition studies.




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Early Prediction and Impact Assessment of CYP3A4-Related Drug-Drug Interactions for Small-Molecule Anticancer Drugs Using Human-CYP3A4-Transgenic Mouse Models [Articles]

Early detection of drug-drug interactions (DDIs) can facilitate timely drug development decisions, prevent unnecessary restrictions on patient enrollment, resulting in clinical study populations that are not representative of the indicated study population, and allow for appropriate dose adjustments to ensure safety in clinical trials. All of these factors contribute to a streamlined drug approval process and enhanced patient safety. Here we describe a new approach for early prediction of the magnitude of change in exposure for cytochrome P450 (P450) CYP3A4-related DDIs of small-molecule anticancer drugs based on the model-based extrapolation of human-CYP3A4-transgenic mice pharmacokinetics to humans. Victim drugs brigatinib and lorlatinib were evaluated with the new approach in combination with the perpetrator drugs itraconazole and rifampicin. Predictions of the magnitude of change in exposure deviated at most 0.99- to 1.31-fold from clinical trial results for inhibition with itraconazole, whereas exposure predictions for the induction with rifampicin were less accurate, with deviations of 0.22- to 0.48-fold. Results for the early prediction of DDIs and their clinical impact appear promising for CYP3A4 inhibition, but validation with more victim and perpetrator drugs is essential to evaluate the performance of the new method.

SIGNIFICANCE STATEMENT

The described method offers an alternative for the early detection and assessment of potential clinical impact of CYP3A4-related drug-drug interactions. The model was able to adequately describe the inhibition of CYP3A4 metabolism and the subsequent magnitude of change in exposure. However, it was unable to accurately predict the magnitude of change in exposure of victim drugs in combination with an inducer.




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Regulation of Human Hydrolases and Its Implications in Pharmacokinetics and Pharmacodynamics [Special Section on New and Emerging Areas and Technologies in Drug Metabolism and Disposition, Part II]

Hydrolases represent an essential class of enzymes indispensable for the metabolism of various clinically essential medications. Individuals exhibit marked differences in the expression and activation of hydrolases, resulting in significant variability in the pharmacokinetics (PK) and pharmacodynamics (PD) of drugs metabolized by these enzymes. The regulation of hydrolase expression and activity involves both genetic polymorphisms and nongenetic factors. This review examines the current understanding of genetic and nongenetic regulators of six clinically significant hydrolases, including carboxylesterase (CES)-1 CES2, arylacetamide deacetylase (AADAC), paraoxonase (PON)-1 PON3, and cathepsin A (CTSA). We explore genetic variants linked to the expression and activity of the hydrolases and their effects on the PK and PD of their substrate drugs. Regarding nongenetic regulators, we focus on the inhibitors and inducers of these enzymes. Additionally, we examine the developmental expression patterns and gender differences in the hydrolases when pertinent information was available. Many genetic and nongenetic regulators were found to be associated with the expression and activity of the hydrolases and PK and PD. However, hydrolases remain generally understudied compared with other drug-metabolizing enzymes, such as cytochrome P450s. The clinical significance of genetic and nongenetic regulators has not yet been firmly established for the majority of hydrolases. Comprehending the mechanisms that underpin the regulation of these enzymes holds the potential to refine therapeutic regimens, thereby enhancing the efficacy and safety of drugs metabolized by the hydrolases.

SIGNIFICANCE STATEMENT

Hydrolases play a crucial role in the metabolism of numerous clinically important medications. Genetic polymorphisms and nongenetic regulators can affect hydrolases’ expression and activity, consequently influencing the exposure and clinical outcomes of hydrolase substrate drugs. A comprehensive understanding of hydrolase regulation can refine therapeutic regimens, ultimately enhancing the efficacy and safety of drugs metabolized by the enzymes.