act Here's How the Inflation Reduction Act Will Lower the Cost of Health Care By www.medicinenet.com Published On :: Wed, 17 Aug 2022 00:00:00 PDT Title: Here's How the Inflation Reduction Act Will Lower the Cost of Health CareCategory: Health NewsCreated: 8/17/2022 12:00:00 AMLast Editorial Review: 8/17/2022 12:00:00 AM Full Article
act Many Older Women Have Active Sex Lives, But Menopause Can Interfere By www.medicinenet.com Published On :: Thu, 19 May 2022 00:00:00 PDT Title: Many Older Women Have Active Sex Lives, But Menopause Can InterfereCategory: Health NewsCreated: 5/18/2022 12:00:00 AMLast Editorial Review: 5/19/2022 12:00:00 AM Full Article
act Vegetarian Women at Higher Odds for Hip Fracture By www.medicinenet.com Published On :: Fri, 12 Aug 2022 00:00:00 PDT Title: Vegetarian Women at Higher Odds for Hip FractureCategory: Health NewsCreated: 8/11/2022 12:00:00 AMLast Editorial Review: 8/12/2022 12:00:00 AM Full Article
act Picture of Nickel Contact Dermatitis By www.medicinenet.com Published On :: Thu, 23 Jun 2022 00:00:00 PDT Title: Picture of Nickel Contact DermatitisCategory: ImagesCreated: 2/22/2010 3:07:00 PMLast Editorial Review: 6/23/2022 12:00:00 AM Full Article
act Picture of Nickel Contact Dermatitis from Necklace By www.medicinenet.com Published On :: Tue, 28 Jun 2022 00:00:00 PDT Title: Picture of Nickel Contact Dermatitis from NecklaceCategory: ImagesCreated: 2/22/2010 3:21:00 PMLast Editorial Review: 6/28/2022 12:00:00 AM Full Article
act Prehistoric People Drank Animal Milk, Despite Lactose Intolerance By www.medicinenet.com Published On :: Thu, 28 Jul 2022 00:00:00 PDT Title: Prehistoric People Drank Animal Milk, Despite Lactose IntoleranceCategory: Health NewsCreated: 7/27/2022 12:00:00 AMLast Editorial Review: 7/28/2022 12:00:00 AM Full Article
act SIBO (Small Intestinal Bacterial Overgrowth) By www.medicinenet.com Published On :: Mon, 8 Aug 2022 00:00:00 PDT Title: SIBO (Small Intestinal Bacterial Overgrowth)Category: Diseases and ConditionsCreated: 10/28/2005 12:00:00 AMLast Editorial Review: 8/8/2022 12:00:00 AM Full Article
act Impaired lung function and associated risk factors in children born prematurely: a systematic review and meta-analysis By err.ersjournals.com Published On :: 2024-10-09T00:15:15-07:00 Background Immature lung development and respiratory morbidity place preterm-born children at high risk of long-term pulmonary sequelae. This systematic review and meta-analysis aims to quantify lung function in preterm-born children and identify risk factors for a compromised lung function. Methods We searched MEDLINE, Embase, Cochrane Library, Web of Science and Scopus for relevant studies published on preterm cohorts born since 1990. Studies comparing forced expiratory volume in 1 s (FEV1) in preterm-born children aged ≥5 years to term-born controls or normative data were included. Study quality was assessed using the Newcastle–Ottawa Scale for cohort studies. Standardised mean differences in FEV1 and secondary spirometry outcomes per study were pooled using meta-analysis. The impact of different demographic and neonatal variables on studies’ FEV1 effect sizes was investigated by meta-regression analyses. Certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations framework. Results We identified 42 studies with unique cohorts including 4743 preterm children and 9843 controls. Median gestational age in the studies was 28.0 weeks and age at assessment ranged from 6.7 to 16.7 years. Preterm children had lower FEV1 than controls (–0.58 sd, 95% CI –0.69– –0.47 sd, p<0.001) resulting in a relative risk of 2.9 (95% CI 2.4–3.4) for abnormal outcome, with high certainty of evidence. FEV1 was significantly associated with gestational age, birthweight, bronchopulmonary dysplasia and invasive mechanical ventilation in univariate meta-regression analyses (R2=36–96%). Conclusion This systematic review shows robust evidence of impaired lung function in preterm-born children with a high certainty of evidence. Full Article
act Systematic identification of interchromosomal interaction networks supports the existence of specialized RNA factories [METHODS] By genome.cshlp.org Published On :: 2024-10-29T06:46:08-07:00 Most studies of genome organization have focused on intrachromosomal (cis) contacts because they harbor key features such as DNA loops and topologically associating domains. Interchromosomal (trans) contacts have received much less attention, and tools for interrogating potential biologically relevant trans structures are lacking. Here, we develop a computational framework that uses Hi-C data to identify sets of loci that jointly interact in trans. This method, trans-C, initiates probabilistic random walks with restarts from a set of seed loci to traverse an input Hi-C contact network, thereby identifying sets of trans-contacting loci. We validate trans-C in three increasingly complex models of established trans contacts: the Plasmodium falciparum var genes, the mouse olfactory receptor "Greek islands," and the human RBM20 cardiac splicing factory. We then apply trans-C to systematically test the hypothesis that genes coregulated by the same trans-acting element (i.e., a transcription or splicing factor) colocalize in three dimensions to form "RNA factories" that maximize the efficiency and accuracy of RNA biogenesis. We find that many loci with multiple binding sites of the same DNA-binding proteins interact with one another in trans, especially those bound by factors with intrinsically disordered domains. Similarly, clustered binding of a subset of RNA-binding proteins correlates with trans interaction of the encoding loci. We observe that these trans-interacting loci are close to nuclear speckles. These findings support the existence of trans-interacting chromatin domains (TIDs) driven by RNA biogenesis. Trans-C provides an efficient computational framework for studying these and other types of trans interactions, empowering studies of a poorly understood aspect of genome architecture. Full Article
act Global characterization of somatic mutations and DNA methylation changes during vegetative propagation in strawberries [RESEARCH] By genome.cshlp.org Published On :: 2024-10-29T06:46:07-07:00 Somatic mutations arise and accumulate during tissue culture and vegetative propagation, potentially affecting various traits in horticultural crops, but their characteristics are still unclear. Here, somatic mutations in regenerated woodland strawberry derived from tissue culture of shoot tips under different conditions and 12 cultivated strawberry individuals are analyzed by whole genome sequencing. The mutation frequency of single nucleotide variants is significantly increased with increased hormone levels or prolonged culture time in the range of 3.3 x 10–8–3.0 x 10–6 mutations per site. CG methylation shows a stable reduction (0.71%–8.03%) in regenerated plants, and hypoCG-DMRs are more heritable after sexual reproduction. A high-quality haplotype-resolved genome is assembled for the strawberry cultivar "Beni hoppe." The 12 "Beni hoppe" individuals randomly selected from different locations show 4731–6005 mutations relative to the reference genome, and the mutation frequency varies among the subgenomes. Our study has systematically characterized the genetic and epigenetic variants in regenerated woodland strawberry plants and different individuals of the same strawberry cultivar, providing an accurate assessment of somatic mutations at the genomic scale and nucleotide resolution in plants. Full Article
act Chromatin interaction maps identify oncogenic targets of enhancer duplications in cancer [RESEARCH] By genome.cshlp.org Published On :: 2024-10-29T06:46:07-07:00 As a major type of structural variants, tandem duplication plays a critical role in tumorigenesis by increasing oncogene dosage. Recent work has revealed that noncoding enhancers are also affected by duplications leading to the activation of oncogenes that are inside or outside of the duplicated regions. However, the prevalence of enhancer duplication and the identity of their target genes remains largely unknown in the cancer genome. Here, by analyzing whole-genome sequencing data in a non-gene-centric manner, we identify 881 duplication hotspots in 13 major cancer types, most of which do not contain protein-coding genes. We show that the hotspots are enriched with distal enhancer elements and are highly lineage-specific. We develop a HiChIP-based methodology that navigates enhancer–promoter contact maps to prioritize the target genes for the duplication hotspots harboring enhancer elements. The methodology identifies many novel enhancer duplication events activating oncogenes such as ESR1, FOXA1, GATA3, GATA6, TP63, and VEGFA, as well as potentially novel oncogenes such as GRHL2, IRF2BP2, and CREB3L1. In particular, we identify a duplication hotspot on Chromosome 10p15 harboring a cluster of enhancers, which skips over two genes, through a long-range chromatin interaction, to activate an oncogenic isoform of the NET1 gene to promote migration of gastric cancer cells. Focusing on tandem duplications, our study substantially extends the catalog of noncoding driver alterations in multiple cancer types, revealing attractive targets for functional characterization and therapeutic intervention. Full Article
act Wonca Europe 2023 Definition of General Practice/Family Medicine: New Needs New Content By www.jabfm.org Published On :: 2024-10-25T09:26:14-07:00 Full Article
act Impact of COVID-19 on Chronic Ambulatory-Care-Sensitive Condition Emergency Department Use Among Older Adults By www.jabfm.org Published On :: 2024-10-25T09:26:14-07:00 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. Full Article
act Impact of Point of Care Hemoglobin A1c Testing on Time to Therapeutic Intervention By www.jabfm.org Published On :: 2024-10-25T09:26:14-07:00 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. Full Article
act A Comprehensive Guide to Long-Acting Injectable Antipsychotics for Primary Care Clinicians By www.jabfm.org Published On :: 2024-10-25T09:26:14-07:00 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. Full Article
act A Qualitative Analysis of a Primary Care Medical-Legal Partnership: Impact, Barriers, and Facilitators By www.jabfm.org Published On :: 2024-10-25T09:26:14-07:00 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. Full Article
act Physician Satisfaction Should Be the Measure of Electronic Health Record Quality for the Nation By www.jabfm.org Published On :: 2024-10-25T09:26:14-07:00 Full Article
act Simulation in Mechanical Ventilation Training: Integrating Best Practices for Effective Education By rc.rcjournal.com Published On :: 2024-10-25T05:44:13-07:00 Full Article
act Downstream Effects of Market Changes on Inhalers: Impacts on Individuals With Chronic Lung Disease By rc.rcjournal.com Published On :: 2024-10-25T05:44:13-07:00 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. Full Article
act Exploring the Impact of Varied Design Approaches and Materials in Respiratory Therapy Education By rc.rcjournal.com Published On :: 2024-10-25T05:44:13-07:00 Full Article
act The Impact of Opioid Prescription on the Occurrence and Outcome of Pneumonia: A Nationwide Cohort Study in South Korea By rc.rcjournal.com Published On :: 2024-10-25T05:44:12-07:00 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. Full Article
act The Impact of Increased PEEP on Hemodynamics, Respiratory Mechanics, and Oxygenation in Pediatric ARDS By rc.rcjournal.com Published On :: 2024-10-25T05:44:12-07:00 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. Full Article
act 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
act 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
act 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
act 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
act 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
act 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
act 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
act Functional Characterization of Reduced Folate Carrier and Protein-Coupled Folate Transporter for Antifolates Accumulation in Non-Small Cell Lung Cancer Cells [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Antifolates are important for chemotherapy in non–small cell lung cancer (NSCLC). They mainly rely on reduced folate carrier (RFC) and proton-coupled folate transporter (PCFT) to enter cells. PCFT is supposed to be the dominant transporter of the two in tumors, as it operates optimally at acidic pH and has limited transport activity at physiological pH, whereas RFC operates optimally at neutral pH. In this study, we found RFC showed a slightly pH-dependent uptake of antifolates, with similar affinity values at pH 7.4 and 6.5. PCFT showed a highly pH-dependent uptake of antifolates, with an optimum pH of 6.0 for pemetrexed and 5.5 for methotrexate. The Michaelis-Menten constant (Km) value of PCFT for pemetrexed at pH 7.4 was more than 10 times higher than that at pH 6.5. Interestingly, we found that antifolate accumulations mediated by PCFT at acidic pH were significantly affected by the efflux transporter, breast cancer resistance protein (BCRP). The highest pemetrexed concentration was observed at pH 7.0–7.4 after a 60-minute accumulation in PCFT-expressing cells, which was further evidenced by the cytotoxicity of pemetrexed, with the IC50 value of pemetrexed at pH 7.4 being one-third of that at pH 6.5. In addition, the in vivo study indicated that increasing PCFT and RFC expression significantly enhanced the antitumor efficacy of pemetrexed despite the high expression of BCRP. These results suggest that both RFC and PCFT are important for antifolates accumulation in NSCLC, although there is an acidic microenvironment and high BCRP expression in tumors. SIGNIFICANCE STATEMENT Evaluating the role of reduced folate carrier (RFC) and proton-coupled folate transporter (PCFT) on antifolates accumulation in non–small cell lung cancer (NSCLC) is necessary for new drug designs. By using cell models, we found both RFC and PCFT were important for antifolates accumulation in NSCLC. Breast cancer resistance protein (BCRP) significantly affected PCFT-mediated antifolates accumulation at acidic pH but not RFC-mediated pemetrexed accumulation at physiological pH. High expression of PCFT or RFC enhanced the cytotoxicity and antitumor effect of pemetrexed. Full Article
act Nonclinical Pharmacokinetics Study of OLX702A-075-16, N-Acetylgalactosamine Conjugated Asymmetric Small Interfering RNA (GalNAc-asiRNA) [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 In this study, the nonclinical pharmacokinetics of OLX702A-075-16, an RNA interference therapeutic currently in development, were investigated. OLX702A-075-16 is a novel N-acetylgalactosamine conjugated asymmetric small-interfering RNA (GalNAc-asiRNA) used for the treatment of an undisclosed liver disease. Its unique 16/21-mer asymmetric structure reduces nonspecific off-target effects without compromising efficacy. We investigated the plasma concentration, tissue distribution, metabolism, and renal excretion of OLX702A-075-16 following a subcutaneous administration in mice and rats. For bioanalysis, high-performance liquid chromatography with fluorescence detection was used. The results showed rapid clearance from plasma (0.5 to 1.5 hours of half-life) and predominant distribution to the liver and/or kidney. Less than 1% of the liver concentration of OLX702A-075-16 was detected in the other tissues. Metabolite profiling using liquid chromatography coupled with high-resolution mass spectrometry revealed that the intact duplex OLX702A-075-16 was the major compound in plasma. The GalNAc moiety was predominantly metabolized from the sense strand in the liver, with the unconjugated sense strand of OLX702A-075-16 accounting for more than 95% of the total exposure in the rat liver. Meanwhile, the antisense strand was metabolized by the sequential loss of nucleotides from the 3'-terminus by exonuclease, with the rat liver samples yielding the most diverse truncated forms of metabolites. Urinary excretion over 96 hours was less than 1% of the administered dose in rats. High plasma protein binding of OLX702A-075-16 likely inhibited its clearance through renal filtration. SIGNIFICANCE STATEMENT This study presents the first comprehensive characterization of the in vivo pharmacokinetics of GalNAc-asiRNA. The pharmacokinetic insights gained from this research will aid in understanding toxicology and efficacy, optimizing delivery platforms, and improving the predictive power of preclinical species data for human applications. Full Article
act Comparison of the CYP3A Selective Inhibitors CYP3cide, Clobetasol, and Azamulin for Their Potential to Distinguish CYP3A7 Activity in the Presence of CYP3A4/5 [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 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. Full Article
act Early Prediction and Impact Assessment of CYP3A4-Related Drug-Drug Interactions for Small-Molecule Anticancer Drugs Using Human-CYP3A4-Transgenic Mouse Models [Articles] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 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. Full Article
act Assessing Trends in Cytokine-CYP Drug Interactions and Relevance to Drug Dosing [Special Section on New and Emerging Areas and Technologies in Drug Metabolism and Disposition, Part II-Minireview] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 The regulation of drug-metabolizing enzymes and transporters by cytokines has been extensively studied in vitro and in clinic. Cytokine-mediated suppression of cytochrome P450 (CYP) or drug transporters may increase or decrease the systemic clearance of drug substrates that are primarily cleared via these pathways; neutralization of cytokines by therapeutic proteins may thereby alter systemic exposures of such drug substrates. The Food and Drug Administration recommends evaluating such clinical drug interactions during clinical development and has provided labeling recommendations for therapeutic proteins. To determine the clinical relevance of these drug interactions to dose adjustments, trends in steady-state exposures of CYP-sensitive substrates coadministered with cytokine modulators as reported in the University of Washington Drug Interaction Database were extracted and examined for each of the CYPs. Coadministration of cytochrome P450 family 3 subfamily A (CYP3A) (midazolam/simvastatin), cytochrome P450 subfamily 2C19 (omeprazole), or cytochrome P450 subfamily 1A2 (caffeine/tizanidine) substrates with anti-interleukin-6 and with anti-interleukin-23 therapeutics led to changes in systemic exposures of CYP substrates ranging from ~ –58% to ~35%; no significant trends were observed for cytochrome P450 subfamily 2D6 (dextromethorphan) and cytochrome P450 subfamily 2C9 (warfarin) substrates. Although none of these changes in systemic exposures have been reported as clinically meaningful, dose adjustment of midazolam for optimal sedation in acute care settings has been reported. Simulated concentration-time profiles of midazolam under conditions of elevated cytokine levels when coadministered with tocilizumab, suggest a ~six- to sevenfold increase in midazolam clearance, suggesting potential implications of cytokine–CYP drug interactions on dose adjustments of sensitive CYP3A substrates in acute care settings. Additionally, this article also provides a brief overview of nonclinical and clinical assessments of cytokine–CYP drug interactions in drug discovery and development. SIGNIFICANCE STATEMENT There has been significant progress in understanding cytokine-mediated drug interactions for CYP-sensitive substrates. This article provides an overview of the progress in this field, including a trend analysis of systemic exposures of CYP-sensitive substrates coadministered with anti-interleukin therapeutics. In addition, the review also provides a perspective of current methods used to assess these drug interactions during drug development and a focus on individualized medicine, particularly in acute care settings. Full Article
act Characterizing the Distribution of a Stimulator of Interferon Genes Agonist and Its Metabolites in Mouse Liver by Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry [Special Section on New and Emerging Areas and Technologies in Drug Met By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 A STING (stimulator of interferon genes) agonist GSK3996915 under investigation in early discovery for hepatitis B was orally dosed to a mouse model for understanding the parent drug distribution in liver, the target organ. Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) was used to quantify the distribution of GSK3996915 in liver collected from mice administered a single oral dose at 90 mg/kg. GSK3996915 was detected with a zonal distribution localized in the portal triad and highly concentrated in the main bile ducts, indicating clearance through biliary excretion. High spatial resolution imaging showed the distribution of the parent drug localized to the cellular populations in the sinusoids, including the Kupffer cells. Additionally, a series of drug-related metabolites were observed to be localized in the central zones of the liver. These results exemplify the potential of utilizing MALDI IMS for measuring not only quantitative drug distribution and target exposure but also drug metabolism and elimination in a single suite of experiments. SIGNIFICANCE STATEMENT An integrated imaging approach utilizing matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) complemented with immunohistochemistry (IHC) and histology was used to address the question of target exposure at the cellular level. Localized quantification of the parent drug in the target organ and identification of potential metabolites in the context of tissue histology were also achieved in one experimental suite to support characterization of pharmacokinetic properties of the drug in the early discovery stage.: Full Article
act Evaluating Drug-Drug Interaction Risk Associated with Peptide Analogs Using advanced In Vitro Systems [Special Section on New and Emerging Areas and Technologies in Drug Metabolism and Disposition, Part II] By dmd.aspetjournals.org Published On :: 2024-10-16T09:02:03-07:00 Drug–drug interaction (DDI) assessment of therapeutic peptides is an evolving area. The industry generally follows DDI guidelines for small molecules, but the translation of data generated with commonly used in vitro systems to in vivo is sparse. In the current study, we investigated the ability of advanced human hepatocyte in vitro systems, namely HepatoPac, spheroids, and Liver-on-a-chip, to assess potential changes in regulation of CYP1A2, CYP2B6, CYP3A4, SLCO1B1, and ABCC2 in the presence of selected therapeutic peptides, proteins, and small molecules. The peptide NN1177, a glucagon and GLP-1 receptor co-agonist, did not suppress mRNA expression or activity of CYP1A2, CYP2B6, and CYP3A4 in HepatoPac, spheroids, or Liver-on-a-chip; these findings were in contrast to the data obtained in sandwich cultured hepatocytes. No effect of NN1177 on SLCO1B1 and ABCC2 mRNA was observed in any of the complex systems. The induction magnitude differed across the systems (e.g., rifampicin induction of CYP3A4 mRNA ranged from 2.8-fold in spheroids to 81.2-fold in Liver-on-a-chip). Small molecules, obeticholic acid and abemaciclib, showed varying responses in HepatoPac, spheroids, and Liver-on-a-chip, indicating a need for EC50 determinations to fully assess translatability data. HepatoPac, the most extensively investigated in this study (3 donors), showed high potential to investigate DDIs associated with CYP regulation by therapeutic peptides. Spheroids and Liver-on-a-chip were only assessed in one hepatocyte donor and further evaluations are required to confirm their potential. This study establishes an excellent foundation toward the establishment of more clinically-relevant in vitro tools for evaluation of potential DDIs with therapeutic peptides. SIGNIFICANT STATEMENT At present, there are no guidelines for drug–drug interaction (DDI) assessment of therapeutic peptides. Existing in vitro methods recommended for assessing small molecule DDIs do not appear to translate well for peptide drugs, complicating drug development for these moieties. Here, we establish evidence that complex cellular systems have potential to be used as more clinically-relevant tools for the in vitro DDI evaluation of therapeutic peptides. Full Article
act Inhibitory Actions of Potentiating Neuroactive Steroids in the Human {alpha}1{beta}3{gamma}2L {gamma}-Aminobutyric Acid Type A Receptor [Article] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 The -aminobutyric acid type A (GABAA) receptor is modulated by a number of neuroactive steroids. Sulfated steroids and 3β-hydroxy steroids inhibit, while 3α-hydroxy steroids typically potentiate the receptor. Here, we have investigated inhibition of the α1β32L GABAA receptor by the endogenous neurosteroid 3α-hydroxy-5β-pregnan-20-one (3α5βP) and the synthetic neuroactive steroid 3α-hydroxy-5α-androstane-17β-carbonitrile (ACN). The receptors were expressed in Xenopus oocytes. All experiments were done using two-electrode voltage-clamp electrophysiology. In the presence of low concentrations of GABA, 3α5βP and ACN potentiate the GABAA receptor. To reveal inhibition, we conducted the experiments on receptors activated by the combination of a saturating concentration of GABA and propofol to fully activate the receptors and mask potentiation, or on mutant receptors in which potentiation is ablated. Under these conditions, both steroids inhibited the receptor with IC50s of ~13 μM and maximal inhibitory effects of 70–90%. Receptor inhibition by 3α5βP was sensitive to substitution of the α1 transmembrane domain (TM) 2-2' residue, previously shown to ablate inhibition by pregnenolone sulfate. However, results of coapplication studies and the apparent lack of state dependence suggest that pregnenolone sulfate and 3α5βP inhibit the GABAA receptor independently and through distinct mechanisms. Mutations to the neurosteroid binding sites in the α1 and β3 subunits statistically significantly, albeit weakly and incompletely, reduced inhibition by 3α5βP and ACN. SIGNIFICANCE STATEMENT The heteromeric GABAA receptor is inhibited by sulfated steroids and 3β-hydroxy steroids, while 3α-hydroxy steroids are considered to potentiate the receptor. We show here that 3α-hydroxy steroids have inhibitory effects on the α1β32L receptor, which are observed in specific experimental settings and are expected to manifest under different physiological conditions. Full Article
act Simplified Method for Kinetic and Thermodynamic Screening of Cardiotonic Steroids through the K+-Dependent Phosphatase Activity of Na+/K+-ATPase with Chromogenic pNPP Substrate [Article] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 The antitumor effect of cardiotonic steroids (CTS) has stimulated the search for new methods to evaluate both kinetic and thermodynamic aspects of their binding to Na+/K+-ATPase (IUBMB Enzyme Nomenclature). We propose a real-time assay based on a chromogenic substrate for phosphatase activity (pNPPase activity), using only two concentrations with an inhibitory progression curve, to obtain the association rate (kon), dissociation rate (koff), and equilibrium (Ki) constants of CTS for the structure-kinetics relationship in drug screening. We show that changing conditions (from ATPase to pNPPase activity) resulted in an increase of Ki of the cardenolides digitoxigenin, essentially due to a reduction of kon. In contrast, the Ki of the structurally related bufadienolide bufalin increased much less due to the reduction of its koff partially compensating the decrease of its kon. When evaluating the kinetics of 15 natural and semisynthetic CTS, we observed that both kon and koff correlated with Ki (Spearman test), suggesting that differences in potency depend on variations of both kon and koff. A rhamnose in C3 of the steroidal nucleus enhanced the inhibitory potency by a reduction of koff rather than an increase of kon. Raising the temperature did not alter the koff of digitoxin, generating a H (koff) of –10.4 ± 4.3 kJ/mol, suggesting a complex dissociation mechanism. Based on a simple and inexpensive methodology, we determined the values of kon, koff, and Ki of the CTS and provided original kinetics and thermodynamics differences between CTS that could help the design of new compounds. SIGNIFICANCE STATEMENT This study describes a fast, simple, and cost-effective method for the measurement of phosphatase pNPPase activity enabling structure-kinetics relationships of Na+/K+-ATPase inhibitors, which are important compounds due to their antitumor effect and endogenous role. Using 15 compounds, some of them original, this study was able to delineate the kinetics and/or thermodynamics differences due to the type of sugar and lactone ring present in the steroid structure. Full Article
act Arachidonic Acid Directly Activates the Human DP2 Receptor [Article] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 Aberrant type 2 inflammatory responses are the underlying cause of the pathophysiology of allergic asthma, allergic rhinitis, and other atopic diseases, with an alarming prevalence in relevant parts of the Western world. A bulk of evidence points out the important role of the DP2 receptor in these inflammation processes. A screening of different polyunsaturated fatty acids at a fluorescence resonance energy transfer–based DP2 receptor conformation sensor expressed in human embryonic kidney (HEK) cells revealed an agonistic effect of the prostaglandin (PG)-D2 precursor arachidonic acid on DP2 receptor activity of about 80% of the effect induced by PGD2. In a combination of experiments at the conformation sensor and using a bioluminescence resonance energy transfer–based G protein activation sensor expressed together with DP2 receptor wild type in HEK cells, we found that arachidonic acid acts as a direct activator of the DP2 receptor, but not the DP1 receptor, in a concentration range considered physiologically relevant. Pharmacological inhibition of cyclooxygenases and lipoxygenases as well as cytochrome P450 did not lead to a diminished arachidonic acid response on the DP2 receptor, confirming a direct action of arachidonic acid on the receptor. SIGNIFICANCE STATEMENT This study identified the prostaglandin precursor arachidonic acid to directly activate the DP2 receptor, a G protein–coupled receptor that is known to play an important role in type 2 inflammation. Full Article
act Going Rogue: Mechanisms, Regulation, and Roles of Mutationally Activated G{alpha} in Human Cancer [Minireview] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 G protein–coupled receptors (GPCRs) couple to heterotrimeric G proteins, comprised of α and β subunits, to convert extracellular signals into activation of intracellular signaling pathways. Canonically, GPCR-mediated activation results in the exchange of GDP for GTP on G protein α subunits (Gα) and the dissociation of Gα-GTP and G protein β subunits (Gβ), both of which can regulate a variety of signaling pathways. Hydrolysis of bound GTP by Gα returns the protein to Gα-GDP and allows reassociation with Gβ to reform the inactive heterotrimer. Naturally occurring mutations in Gα have been found at conserved glutamine and arginine amino acids that disrupt the canonical G protein cycle by inhibiting GTP hydrolysis, rendering these mutants constitutively active. Interestingly, these dysregulated Gα mutants are found in many different cancers due to their ability to sustain aberrant signaling without a need for activation by GPCRs. This review will highlight an increased recognition of the prevalence of such constitutively activating Gα mutations in cancers and the signaling pathways activated. In addition, we will discuss new knowledge regarding how these constitutively active Gα are regulated, how different mutations are biochemically distinct, and how mutationally activated Gα are unique compared with GPCR-activated Gα. Lastly, we will discuss recent progress in developing inhibitors directly targeting constitutively active Gα mutants. SIGNIFICANCE STATEMENT Constitutively activating mutations in G protein α subunits (Gα) widely occur in and contribute to the development of many human cancers. To develop ways to inhibit dysregulated, oncogenic signaling by these mutant Gα, it is crucial to better understand mechanisms that lead to constitutive Gα activation and unique mechanisms that regulate mutationally activated Gα in cells. The prevalence of activating mutations in Gα in various cancers makes Gα proteins compelling targets for the development of therapeutics. Full Article
act Can the International Conference on Population and Development Programme of Action and Cairo Consensus Normalize the Discourse on Population? By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 Full Article
act Sensory-Motor Neuropathy in Mfn2 T105M Knock-in Mice and Its Reversal by a Novel Piperine-Derived Mitofusin Activator [Neuropharmacology] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 Mitochondrial dysfunction is a hallmark of many genetic neurodegenerative diseases, but therapeutic options to reverse mitochondrial dysfunction are limited. While recent studies support the possibility of improving mitochondrial fusion/fission dynamics and motility to correct mitochondrial dysfunction and resulting neurodegeneration in Charcot-Marie-Tooth disease (CMT) and other neuropathies, the clinical utility of reported compounds and relevance of preclinical models are uncertain. Here, we describe motor and sensory neuron dysfunction characteristic of clinical CMT type 2 A in a CRISPR/Casp-engineered Mfn2 Thr105Met (T105M) mutant knock-in mouse. We further demonstrate that daily oral treatment with a novel mitofusin activator derived from the natural product piperine can reverse these neurologic phenotypes. Piperine derivative 8015 promoted mitochondrial fusion and motility in Mfn2-deficient cells in a mitofusin-dependent manner and reversed mitochondrial dysfunction in cultured fibroblasts and reprogrammed motor neurons from a human CMT2A patient carrying the MFN2 T105M mutation. Like previous mitofusin activators, 8015 exhibited stereospecific functionality, but the more active stereoisomer, 8015-P2, is unique in that it has subnanomolar potency and undergoes entero-hepatic recirculation which extends its in vivo half-life. Daily administration of 8015-P2 to Mfn2 T105M knock-in mice for 6 weeks normalized neuromuscular and sensory dysfunction and corrected histological/ultrastructural neurodegeneration and neurogenic myoatrophy. These studies describe a more clinically relevant mouse model of CMT2A and an improved mitofusin activator derived from piperine. We posit that 8015-P2 and other piperine derivatives may benefit CMT2A or other neurodegenerative conditions wherein mitochondrial dysdynamism plays a contributory role. SIGNIFICANCE STATEMENT Mitochondrial dysfunction is widespread and broadly contributory in neurodegeneration, but difficult to target therapeutically. Here, we describe 8015-P2, a new small molecule mitofusin activator with ~10-fold greater potency and improved in vivo pharmacokinetics versus comparators, and demonstrate its rapid reversal of sensory and motor neuron dysfunction in an Mfn2 T105M knock-in mouse model of Charcot-Marie-Tooth disease type 2 A. These findings further support the therapeutic approach of targeting mitochondrial dysdynamism in neurodegeneration. Full Article
act Factors Influencing the Central Nervous System (CNS) Distribution of the Ataxia Telangiectasia Mutated and Rad3-Related Inhibitor Elimusertib (BAY1895344): Implications for the Treatment of CNS Tumors [Metabolism, Transport, and Pharmacogenetics] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 Glioblastoma (GBM) is a disease of the whole brain, with infiltrative tumor cells protected by an intact blood-brain barrier (BBB). GBM has a poor prognosis despite aggressive treatment, in part due to the lack of adequate drug permeability at the BBB. Standard of care GBM therapies include radiation and cytotoxic chemotherapy that lead to DNA damage. Subsequent activation of DNA damage response (DDR) pathways can induce resistance. Various DDR inhibitors, targeting the key regulators of these pathways such as ataxia telangiectasia mutated and Rad3-related (ATR), are being explored as radio- and chemosensitizers. Elimusertib, a novel ATR kinase inhibitor, can prevent repair of damaged DNA, increasing efficacy of DNA-damaging cytotoxic therapies. Robust synergy was observed in vitro when elimusertib was combined with the DNA-damaging agent temozolomide; however, we did not observe improvement with this combination in in vivo efficacy studies in GBM orthotopic tumor-bearing mice. This in vitro–in vivo disconnect was explored to understand factors influencing central nervous system (CNS) distribution of elimusertib and reasons for lack of efficacy. We observed that elimusertib is rapidly cleared from systemic circulation in mice and would not maintain adequate exposure in the CNS for efficacious combination therapy with temozolomide. CNS distribution of elimusertib is partially limited by P-glycoprotein efflux at the BBB, and high binding to CNS tissues leads to low levels of pharmacologically active (unbound) drug in the brain. Acknowledging the potential for interspecies differences in pharmacokinetics, these data suggest that clinical translation of elimusertib in combination with temozolomide for treatment of GBM may be limited. SIGNIFICANCE STATEMENT This study examined the disconnect between the in vitro synergy and in vivo efficacy of elimusertib/temozolomide combination therapy by exploring systemic and central nervous system (CNS) distributional pharmacokinetics. Results indicate that the lack of improvement in in vivo efficacy in glioblastoma (GBM) patient-derived xenograft (PDX) models could be attributed to inadequate exposure of pharmacologically active drug concentrations in the CNS. These observations can guide further exploration of elimusertib for the treatment of GBM or other CNS tumors. Full Article
act Nonclinical Profile of PF-06952229 (MDV6058), a Novel TGF{beta}RI/Activin Like Kinase 5 Inhibitor Supports Clinical Evaluation in Cancer [Drug Discovery and Translational Medicine] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 The development of transforming growth factor βreceptor inhibitors (TGFβRi) as new medicines has been affected by cardiac valvulopathy and arteriopathy toxicity findings in nonclinical toxicology studies. PF-06952229 (MDV6058) selected using rational drug design is a potent and selective TGFβRI inhibitor with a relatively clean off-target selectivity profile and good pharmacokinetic properties across species. PF-06952229 inhibited clinically translatable phospho-SMAD2 biomarker (≥60%) in human and cynomolgus monkey peripheral blood mononuclear cells, as well as in mouse and rat splenocytes. Using an optimized, intermittent dosing schedule (7-day on/7-day off/cycle; 5 cycles), PF-06952229 demonstrated efficacy in a 63-day syngeneic MC38 colon carcinoma mouse model. In the pivotal repeat-dose toxicity studies (rat and cynomolgus monkey), PF-06952229 on an intermittent dosing schedule (5-day on/5-day off cycle; 5 cycles, 28 doses) showed no cardiac-related adverse findings. However, new toxicity findings related to PF-06952229 included reversible hepatocellular (hepatocyte necrosis with corresponding clinically monitorable transaminase increases) and lung (hemorrhage with mixed cell inflammation) findings at ≥ targeted projected clinical efficacious exposures. Furthermore, partially reversible cartilage hypertrophy (trachea and femur in rat; femur in monkey) and partially to fully reversible, clinically monitorable decreases in serum phosphorus and urinary phosphate at ≥ projected clinically efficacious exposures were observed. Given the integral role of TGFβ in endochondral bone formation, cartilage findings in toxicity studies have been observed with other TGFβRi classes of compounds. The favorable cumulative profile of PF-06952229 in biochemical, pharmacodynamic, pharmacokinetic, and nonclinical studies allowed for its evaluation in cancer patients using the intermittent dosing schedule (7-day on/7-day off) and careful protocol-defined monitoring. SIGNIFICANCE STATEMENT Only a few TGFβRi have progressed for clinical evaluation due to adverse cardiac findings in pivotal nonclinical toxicity studies. The potential translations of such findings in patients are of major concern. Using a carefully optimized intermittent dosing schedule, PF-06952229 has demonstrated impressive pharmacological efficacy in the syngeneic MC38 colon carcinoma mouse model. Additionally, a nonclinical toxicology package without cardiovascular liabilities and generally monitorable toxicity profile has been completed. The compound presents an acceptable International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use S9-compliant profile for the intended-to-treat cancer patients. Full Article
act Cannabinoid 2 Receptor Activation Protects against Diabetic Cardiomyopathy through Inhibition of AGE/RAGE-Induced Oxidative Stress, Fibrosis, and Inflammasome Activation [Special Section: Cannabinoid Signaling in Human Health and Disease] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 Oxidative stress, fibrosis, and inflammasome activation from advanced glycation end product (AGE)–receptor of advanced glycation end product (RAGE) interaction contribute to diabetic cardiomyopathy (DCM) formation and progression. Our study revealed the impact of β-caryophyllene (BCP) on activating cannabinoid type 2 receptors (CB2Rs) against diabetic complication, mainly cardiomyopathy and investigated the underlying cell signaling pathways in mice. The murine model of DCM was developed by feeding a high-fat diet with streptozotocin injections. After the development of diabetes, the animals received a 12-week oral BCP treatment at a dose of 50 mg/kg/body weight. BCP treatment showed significant improvement in glucose tolerance and insulin resistance and enhanced serum insulin levels in diabetic animals. BCP treatment effectively reversed the heart remodeling and restored the phosphorylated troponin I and sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a expression. Ultrastructural examination showed reduced myocardial cell injury in DCM mice treated with BCP. The preserved myocytes were found to be associated with reduced expression of AGE/RAGE in DCM mice hearts. BCP treatment mitigated oxidative stress by inhibiting expression of NADPH oxidase 4 and activating phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor erythroid 2–related factor 2 (Nrf2) signaling. Also, BCP suppressed cardiac fibrosis and endothelial-to-mesenchymal transition in DCM mice by inhibiting transforming growth factor β (TGF-β)/suppressor of mothers against decapentaplegic (Smad) signaling. Further, BCP treatment suppressed nucleotide-binding domain, leucine-rich–containing family, pyrin domain–containing-3 (NLRP3) inflammasome activation in DCM mice and alleviated cellular injury to the pancreatic tissues evidenced by significant elevation of the number of insulin-positive cells. To demonstrate a CB2R-dependent mechanism of BCP, another group of DCM mice were pretreated with AM630, a CB2R antagonist. AM630 was observed to abrogate the beneficial effects of BCP in DCM mice. Taken together, BCP demonstrated the potential to protect the myocardium and pancreas of DCM mice mediating CB2R-dependent mechanisms. SIGNIFICANCE STATEMENT BCP, a CB2R agonist, shows protection against DCM. BCP attenuates oxidative stress, inflammation, and fibrosis in DCM via activating CB2Rs. BCP mediating CB2R activation favorably modulates AGE/RAGE, PI3K/AKT/Nrf2β and TGF-β/Smad and (NLRP3) inflammasome in diabetic cardiomyopathy. Full Article
act MIRD Pamphlet No. 30: MIRDfit--A Tool for Fitting of Biodistribution Time-Activity Data for Internal Dosimetry By jnm.snmjournals.org Published On :: 2024-11-01T04:25:31-07:00 In nuclear medicine, estimating the number of radioactive decays that occur in a source organ per unit administered activity of a radiopharmaceutical (i.e., the time-integrated activity coefficient [TIAC]) is an essential task within the internal dosimetry workflow. TIAC estimation is commonly derived by least-squares fitting of various exponential models to organ time–activity data (radiopharmaceutical biodistribution). Rarely, however, are methods used to objectively determine the model that best characterizes the data. Additionally, the uncertainty associated with the resultant TIAC is generally not evaluated. As part of the MIRDsoft initiative, MIRDfit has been developed to offer a biodistribution fitting software solution that provides the following essential features and advantages for internal dose assessment: nuclear medicine–appropriate fit functions; objective metrics for guiding best-fit selection; TIAC uncertainty calculation; quality control and data archiving; integration with MIRDcalc software for dose calculation; and a user-friendly Excel-based interface. For demonstration and comparative validation of MIRDfit’s performance, TIACs were derived from serial imaging studies involving 18F-FDG and 177Lu-DOTATATE using MIRDfit. These TIACs were then compared with TIAC estimates obtained using other software. In most cases, the TIACs agreed within approximately 10% between MIRDfit and the other software. MIRDfit has been endorsed by the MIRD Committee of the Society of Nuclear Medicine and Molecular Imaging and has been integrated into the MIRDsoft suite of free dosimetry software; it is available for download at no user cost (https://mirdsoft.org/). Full Article
act Evaluation of Fibroblast Activation Protein Expression Using 68Ga-FAPI46 PET in Hypertension-Induced Tissue Changes By jnm.snmjournals.org Published On :: 2024-11-01T04:25:31-07:00 Chronic hypertension leads to injury and fibrosis in major organs. Fibroblast activation protein (FAP) is one of key molecules in tissue fibrosis, and 68Ga-labeled FAP inhibitor-46 (FAPI46) PET is a recently developed method for evaluating FAP. The aim of this study was to evaluate FAP expression and fibrosis in a hypertension model and to test the feasibility of 68Ga-FAPI46 PET in hypertension. Methods: Hypertension was induced in mice by angiotensin II infusion for 4 wk. 68Ga-FAPI46 biodistribution studies and PET scanning were conducted at 1, 2, and 4 wk after hypertension modeling, and uptake in the major organs was measured. The FAP expression and fibrosis formation of the heart and kidney tissues were analyzed and compared with 68Ga-FAPI46 uptake. Subgroups of the hypertension model underwent angiotensin receptor blocker administration and high-dose FAPI46 blocking, for comparison. As a preliminary human study, 68Ga-FAPI46 PET images of lung cancer patients were analyzed and compared between hypertension and control groups. Results: Uptake of 68Ga-FAPI46 in the heart and kidneys was significantly higher in the hypertension group than in the sham group as early as week 1 and decreased after week 2. The uptake was specifically blocked in the high-dose blocking study. Immunohistochemistry also revealed FAP expression in both heart and kidney tissues. However, overt fibrosis was observed in the heart, whereas it was absent from the kidneys. The angiotensin receptor blocker–treated group showed lower uptake in the heart and kidneys than did the hypertension group. In the pilot human study, renal uptake of 68Ga-FAPI46 significantly differed between the hypertension and control groups. Conclusion: In hypertension, FAP expression is increased in the heart and kidneys from the early phases and decreases over time. FAP expression appears to represent fibrosis activity preceding or underlying fibrotic tissue formation. 68Ga-FAPI46 PET has potential as an effective imaging method for evaluating FAP expression in progressive fibrosis by hypertension. Full Article
act Impact of 18F-FES PET/CT on Clinical Decisions in the Management of Recurrent or Metastatic Breast Cancer By jnm.snmjournals.org Published On :: 2024-11-01T04:25:31-07:00 The clinical impact of 16α-18F-fluoro-17β-estradiol (18F-FES) PET/CT on patient management has not been well investigated. The aim of this study was to assess the clinical impact of 18F-FES PET/CT on the management of patients with recurrent or metastatic breast cancer. Methods: Study subjects were identified retrospectively from a database of a prospective trial for postmarketing surveillance of 18F-FES between 2021 and 2023. Patients who were suspected or known to have recurrent or metastatic estrogen receptor–positive breast cancer based on a routine standard workup were included. Planned management before and actual management after 18F-FES PET/CT were assessed by 2 experienced medical oncologists via medical chart review. A 5-point questionnaire was provided to evaluate the value of 18F-FES PET/CT for management planning. The rate of intention-to-treat and interdisciplinary changes, and the impact of 18F-FES PET/CT according to PET/CT result or clinical indication, were examined. Results: Of the 344 included patients, 120 (35%) experienced a change in management after 18F-FES PET/CT. In 139 (40%) patients,18F-FES PET/CT supported the existing management decision without a change in management. Intention-to-treat and interdisciplinary changes accounted for 64% (77/120) and 68% (82/120) of all changes, respectively. A higher rate of change was observed when lesions were 18F-FES–negative (44% [36/81]) than 18F-FES–positive (30% [51/172]) or mixed 18F-FES–positive/negative (36% [33/91]). Regarding clinical indications, the highest rate of change was shown when evaluating the origins of metastasis of double primary cancers (64% [9/14]). Conclusion: 18F-FES PET/CT modified the management of recurrent or metastatic breast cancer, serving as an impactful imaging modality in clinical practice. Full Article
act Best Patient Care Practices for Administering PSMA-Targeted Radiopharmaceutical Therapy By jnm.snmjournals.org Published On :: 2024-11-01T04:25:31-07:00 Optimal patient management protocols for metastatic castration-resistant prostate cancer (mCRPC) are poorly defined and even further complexified with new therapy approvals, such as radiopharmaceuticals. The prostate-specific membrane antigen (PSMA)–targeted agent 177Lu vipivotide tetraxetan ([177Lu]Lu-PSMA-617), approved after the phase III VISION study, presents physicians with additional aspects of patient management, including specific adverse event (AE) monitoring and management, as well as radiation safety. Drawing on our experience as VISION study investigators, here we provide guidance on best practices for delivering PSMA-targeted radiopharmaceutical therapy (RPT) to patients with mCRPC. After a comprehensive review of published evidence and guidelines on RPT management in prostate cancer, we identified educational gaps in managing the radiation safety and AEs associated with [177Lu]Lu-PSMA-617. Our results showed that providing sufficient education on AEs (e.g., fatigue and dry mouth) and radiation safety principles is key to effective delivery and management of patient expectations. Patient counseling by health care professionals, across disciplines, is a cornerstone of optimal patient management during PSMA-targeted RPT. Multidisciplinary collaboration is crucial, and physicians must adhere to radiation safety protocols and counsel patients on radiation safety considerations. Treatment with [177Lu]Lu-PSMA-617 is generally well tolerated; however, additional interventions may be required, such as dosing modification, medications, or transfusions. Urinary incontinence can be challenging in the context of radiation safety. Multidisciplinary collaboration between medical oncologists and nuclear medicine teams ensures that patients are monitored and managed safely and efficiently. In clinical practice, the benefit-to-risk ratio should always be evaluated on a case-by-case basis. Full Article
act Drug-Drug Interactions and Synergy: From Pharmacological Models to Clinical Application [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 This review explores the concept of synergy in pharmacology, emphasizing its importance in optimizing treatment outcomes through the combination of drugs with different mechanisms of action. Synergy, defined as an effect greater than the expected additive effect elicited by individual agents according to specific predictive models, offers a promising approach to enhance therapeutic efficacy while minimizing adverse events. The historical evolution of synergy research, from ancient civilizations to modern pharmacology, highlights the ongoing quest to understand and harness synergistic interactions. Key concepts, such as concentration-response curves, additive effects, and predictive models, are discussed in detail, emphasizing the need for accurate assessment methods throughout translational drug development. Although various mathematical models exist for synergy analysis, selecting the appropriate model and software tools remains a challenge, necessitating careful consideration of experimental design and data interpretation. Furthermore, this review addresses practical considerations in synergy assessment, including preclinical and clinical approaches, mechanism of action, and statistical analysis. Optimizing synergy requires attention to concentration/dose ratios, target site localization, and timing of drug administration, ensuring that the benefits of combination therapy detected bench-side are translatable into clinical practice. Overall, the review advocates for a systematic approach to synergy assessment, incorporating robust statistical analysis, effective and simplified predictive models, and collaborative efforts across pivotal sectors, such as academic institutions, pharmaceutical companies, and regulatory agencies. By overcoming critical challenges and maximizing therapeutic potential, effective synergy assessment in drug development holds promise for advancing patient care. Significance Statement Combining drugs with different mechanisms of action for synergistic interactions optimizes treatment efficacy and safety. Accurate interpretation of synergy requires the identification of the expected additive effect. Despite innovative models to predict the additive effect, consensus in drug-drug interactions research is lacking, hindering the bench-to-bedside development of combination therapies. Collaboration among science, industry, and regulation is crucial for advancing combination therapy development, ensuring rigorous application of predictive models in clinical settings. Full Article