Pharmacology Research & Perspectives

ABSTRACT Background: Post-traumatic elbow stiffness is a recognised complication following orthopaedic trauma surgery, occurring in 10-15% of trauma patients sustaining injuries. Pain remains the primary barrier to physiotherapy compliance, with surgical arthrolysis carrying recurrence rates of up to 34%. The supraclavicular brachial plexus block, referred to as the 'spinal of the arm', provides anaesthesia and analgesia to the entire upper limb below the shoulder. A structured non-surgical approach combining continuous catheter analgesia with timed rehabilitation was identified as an unmet need in this patient group. Methods: A single-centre retrospective observational study was conducted on data of patients treated for post-surgical upper limb stiffness between January 2022 and April 2026. Of 30 patients identified, 28 with elbow involvement formed the primary analysis group following exclusion of 2 patients with isolated wrist stiffness and complex regional pain syndrome. Ultrasound- guided supraclavicular brachial plexus catheters were inserted using the Contiplex system. Patients received 0.5% Bupivacaine (10-15ml) for initial blockade, followed by daily top-up doses of 0.2% Ropivacaine(20ml) given 30 minutes prior to structured physiotherapy and CPM sessions for up to 5 days. The primary outcome was change in arc of elbow motion in degrees, measured by the attending orthopaedic consultant using standard goniometry. Results: Complete pre- and post- intervention data were available for all 28 patients. Mean pre-intervention arc of elbow motion was 39.1{degrees}(SD+/-23.2{degrees}), improving to 104.2{degrees}(SD+/- 30.0{degrees}) post-intervention. Mean improvement was 65.1{degrees}(SD+/- 30.6{degrees} ); 95% CI 53.8{degrees} to 76.4{degrees} ; range 10{degrees}-140{degrees} ; paired t-test t=-11.27, p<0.0001). Mean catheter duration was 5.2 days (SD+/- 1.3). Five patients (17.9%) experienced mechanical catheter complications- 3 dislodgements, 1 kinking and 1 block failure- with no episodes of Local Anaesthetic Systemic toxicity, infection or neurological deficit. Conclusion: Continuous supraclavicular brachial plexus catheter analgesia represents a promising, minimally invasive rehabilitation tool for post-surgical elbow stiffness - achieving statistically and clinically meaningful Range of Motion (ROM) improvement through targeted regional analgesia, without the need for surgical intervention. These findings support prospective evaluation of this protocol as a primary non-surgical rehabilitation strategy.

Effective postoperative pain control is essential following laparoscopic cholecystectomy, yet the analgesic value of a standardised 150 mg preoperative dose of pregabalin has not been clearly established. This systematic review and meta-analysis synthesised evidence from seven randomised controlled trials published between 2008 and 2025 to evaluate the efficacy and safety of pregabalin when administered before surgery. Four trials reported 24-hour postoperative pain scores, and pooled analysis demonstrated that pregabalin significantly reduced pain compared with control (SMD = 0.80 lower; 95% CI, 1.42 to 0.18 lower; p = 0.01), although statistical heterogeneity was high (I-squared = 81%). Pregabalin also produced notable reductions in opioid consumption, including fentanyl (SMD = 1.24 lower; p = 0.002) and tramadol (SMD = 4.21 lower; p = 0.002), again with considerable variability across studies. Sedation was slightly increased but did not reach statistical significance, and there were no significant differences in postoperative nausea, vomiting, or headache. Sensitivity analyses supported the stability of these findings. Overall, the results indicate that a single 150 mg preoperative dose of pregabalin meaningfully reduces postoperative pain and opioid requirements following laparoscopic cholecystectomy while maintaining an acceptable safety profile, supporting its use as part of a multimodal analgesic strategy.

Background & Aims: Activation of apoptosis signal-regulating kinase 1 (ASK1), a ubiquitous redox-sensitive kinase, results in inflammation, apoptosis, and fibrosis, key common pathways in human liver disease. SRT-015 is a novel, small molecule inhibitor of ASK1. This study evaluated the in vitro efficacy of SRT-015, compared it to other ASK1 inhibitors, and determined the in vivo efficacy of SRT-015 across multiple acute and chronic liver disease models. Methods: In vitro studies determined the kinase potency and selectivity of SRT-015, and cellular studies were used to demonstrate direct mechanisms of action. The cardiac hERG channel inhibition was assessed and PK determined in rodents and nonhuman primates. In vivo studies evaluated SRT-015 efficacy in rodent models of drug-induced hepatotoxicity (acetaminophen (APAP) overdose), alcohol-associated liver disease (ALD), metabolic-disease associated steatohepatitis (MASH) and cholestatic disease (bile duct ligation, BDL). Results: SRT-015, was demonstrated a selective ASK1 kinase, and SRT-015 treatment directly inhibited fibrosis, apoptosis and inflammation in activated human fibroblasts, hepatocytes and PBMCs, respectively without safety signals or hERG inhibition. Other ASK1 inhibitors had safety concerns or limited functional activity. Liver and kidney selective PK were observed for SRT-015 in all species evaluated. In vivo, SRT-015 treatment was efficacious in the acute mouse APAP overdose and ALD model significantly (P<0.05) decreasing serum ALT. Using a therapeutic diet-induced obesity (DIO)-MASH model with biopsy-verified fibrosis, SRT-015 treatment significantly (P<0.05) inhibited DIO-induced liver enzymes, hepatomegaly, fibrosis, inflammation, and apoptosis independent of body weight loss whereas treatment with selonsertib was ineffective. In a rat cholestatic model, SRT-015 treatment significantly (P<0.05) decreased fibrosis and stellate cell activation. Conclusions: These findings support SRT-015 as a potential therapeutic for human liver diseases of any etiology.

BACKGROUND: Caudal block is widely employed in pediatric lower abdominal surgeries and adult anorectal surgical by its simplicity of operation, reliable efficacy, and high safety. Previous studies have found that the dose of ropivacaine for Caudal block in adults exhibits gender differences. However, it remains unclear whether such differences in the median effective concentration (EC50) of ropivacaine also exist in the elderly population . METHODS: This is a double-blind, prospective study, We enrolled patients aged 60-80 years with ASA physical status I-? who were scheduled for anorectal surgery under caudal anesthesia, and allocated them to 2 study groups according to their gender. Each participant received a single injection of 20mL ropivacaine. Using Dixons up-and-down sequential allocation, the initial concentration of ropivacaine was set at 0.35% and the subsequent concentrations were determined by the analgesic response of the previous patients to the pinprick testing. The concentration change was 0.025%. The EC50 of ropivacaine in each group was determined using the the up-and-down method and probit regression. The primary outcome was the EC50 (95% confidence interval [CI]) of the 2 groups. Data on the surgical time, analgesic duration, and adverse events during surgery were also recorded. RESULTS: This study included a total of 40 elderly patients (20 male and 20 female). The EC50 of ropivacaine for caudal block in elderly male patients was 0.263% (95% CI: 0.179%-0.311%), while that in elderly female patients was 0.281% (95% CI: 0.161%-0.353%). The EC50 of ropivacaine for caudal block in elderly female patients was approximately 6.4% higher than that in elderly male patients. CONCLUSIONS: There is a significant gender difference in the EC50 of ropivacaine for caudal block among the elderly, with elderly female requiring a higher EC50 than male.

Introduction: Progressive multiple sclerosis (MS), including primary progressive MS (PPMS) and non-active secondary progressive MS (nSPMS), remains an unmet need, as few treatments target innate immune pathways. Masitinib (AB1010) is a selective tyrosine kinase inhibitor that targets c-Kit and colony-stimulating factor 1 receptor pathways. This mechanism disrupts mast cell-microglia interactions, key innate immune effectors in progressive MS pathogenesis, reducing neuroinflammation and neuronal damage. In the phase 3 AB07002 trial, masitinib (4.5 mg/kg/d) over 96 weeks met its primary endpoint. Comparable signals in PPMS and nSPMS indicated masitinib benefited both phenotypes. Secondary analyses showed that masitinib lowered the progression to wheelchair dependence (EDSS [&ge;]7, 12 weeks) and reduced the 12-week confirmed EDSS progression risk by 37% versus placebo, although the results were underpowered for these endpoints. Methods: This study aimed to confirm that oral masitinib achieves central nervous system (CNS) concentrations sufficient to modulate CSF1R and wild-type c-Kit, thereby underpinning its neuroprotective potential. Male Sprague Dawley rats (n=12, ~200 g) were administered a single oral dose (30 mg/kg). Plasma and brain samples were collected at 2, 4, 8, and 24 hours post-dose (n=3 per time point). Masitinib (AB1010) and its metabolite (AB3280) were quantified in plasma and brain homogenates using LC-MS/MS. Results: Masitinib reached a brain Cmax of 223.5 ng/mL (~450 nM), exceeding IC50 values for CSF1R and wild-type c-KIT by ~5-fold and 2-fold, respectively, indicating effective CNS target engagement. The active metabolite AB3280 also achieved brain Cmax levels with full inhibitory activity. Masitinib demonstrated consistent CNS penetration supported by a proportional plasma-to-brain exposure relationship. Conclusion: The favorable CNS penetration and safety profile of masitinib, alongside its unique mast cell inhibition, position it as a compelling candidate for progressive MS treatment, either as monotherapy or in combination with other agents. This multifaceted immunomodulatory approach addresses critical unmet needs in progressive MS and supports further clinical development.

Background: Sphingosine 1-phosphate receptor (S1PR) modulators can cause transient, dose-related negative chronotropic effects. Mocravimod is an oral S1PR modulator that is developed as a maintenance therapy in allogenic haematopoietic cell transplantation (allo-HCT). This phase I study evaluated whether two dose-titration regimens attenuate early bradycardia when initiating mocravimod while preserving pharmacokinetic (PK) and pharmacodynamic (PD) activity. Patients and methods: In this randomized, double-blind, placebo-controlled, parallel-group study, healthy adults received once-daily oral mocravimod using either dose titration (DT) regimen DT1 (0.3-2.0 mg with 4-day stepwise escalation) or regimen DT2 (0.5 mg to Day 14, 1.2 mg Days 15-18, then 2 mg), a fixed 2 mg regimen, or placebo for 21 days. The primary endpoint was the number of bradycardia episodes on treatment initiation and dose-escalation days derived from 24-hour Holter monitoring; PK of mocravimod and mocravimod-phosphate (whole blood) and PD effects (absolute lymphocyte count [ALC]) were assessed. Results: Fifty-six participants were randomized and 53 completed the study. Both titration regimens resulted in fewer bradycardia episodes than fixed initiation at 2 mg during the first week of treatment. Differences between titration and fixed dosing were no longer evident after Day 9, consistent with tolerance development. PK profiles were consistent with prior phase I data. By Day 21, DT1 achieved exposures close to the fixed 2 mg regimen, whereas DT2 yielded lower exposures, reflecting slower escalation. Peripheral lymphopenia developed in all active treatment groups and was comparable between regimens by Day 21, returning toward baseline by study end. Safety was similar between titration regimens and placebo, with similar distribution and incidence of adverse events. No serious adverse events occurred. Conclusion: Two practical titration regimens mitigated the early negative chronotropic effect observed with fixed-dose initiation of mocravimod at 2 mg once daily. Importantly, titration preserved the expected PK and PD profile, supporting dose escalation as an effective initiation strategy to improve early cardiac tolerability.

The platelet P2Y1 receptor (P2Y1R) is necessary for inflammation, signalling via Rho-GTPase pathways to elicit functions that are distinct from aggregation (PLC-dependent canonical signalling pathway). Whether these distinct platelet inflammatory functions can be selectively suppressed to preserve hemostasis through the rational design of P2Y1R antagonists has not been explored. In silico molecular docking analysis examined biased nucleotide interactions within the P2Y1R binding pocket. The identified possible key amino acid residues guided rational design to synthesize compounds for pathway selective inhibition, evolving from nucleotide to non-nucleotide structures. The nucleotide analogue KMR-82-13 was predicted to engage distinct regions of the binding pocket and selectively inhibited platelet chemotaxis while preserving aggregation. These findings informed the design of a non-nucleotide compound KSN-159-27, aiming to retain key KMR-82-13-like interactions while improving drug-like properties. Docking and molecular dynamics simulation supported a stable but dynamic binding mode for KSN-159-27 within the P2Y1R pocket, consistent with pathway-selective inhibition. KSN-159-27 displayed characteristics of a pathway selective inverse agonist at P2Y1R towards G12/13-mediated pathways, but not those associated by Gq activation in P2Y1R-transfected HEK293T cells. KSN-159-27 showed functionally selective inhibition for platelet P2Y1R-mediated functions. In vivo, KSN-159-27 suppressed inflammatory cell recruitment, whilst preserving bleeding time and ADP-induced thromboembolic responses, in contrast to the neutral P2Y1R antagonist MRS2500. This first demonstration for the rational design of a pathway selective inverse agonist at platelet P2Y1Rs has significant implications for novel therapeutic strategies developed to safely target platelet activation during inflammation, in contrast to current anti-platelet drugs used in the prevention of thrombosis. Key PointsO_LIBiased inverse platelet P2Y1R agonists selectively supress inflammation whilst preserving hemostasis and the ability of platelets to aggregate. C_LIO_LIBiased inverse agonism selectively inhibited P2Y1R G12/13 (Rho-GTPAse functions) but not Gq activities (PLC functions). C_LI

GLP-1 receptor agonists achieve weight loss but are associated with clinically significant reductions in lean mass. Activin type II receptors (ActRIIA and ActRIIB) mediate signaling of myostatin and activin A, both of which negatively regulate muscle growth, suggesting that dual blockade of these receptors may preserve or increase lean mass while promoting fat loss. In this study, we developed anti-ActRIIA/B antibodies using AI-driven platforms (AlfaDAX) and selected the lead candidate AB130-165 based on in vitro binding, functional blocking, and developability assessments. Compared with a laboratory-prepared bimagrumab analog, AB130-165 exhibited potent dual inhibition of ActRIIA/B signaling, with a 9.5-fold higher functional blocking activity against activin A-induced SMAD signaling and 1054-fold improvements in binding affinity for ActRIIA (KD = 0.204 pM), 10-fold for ActRIIB (KD = 0.243 pM), respectively. In diet-induced obese mice, combination therapy with AB130-165 and semaglutide resulted in a 33.4% body weight reduction, which was superior to semaglutide monotherapy (-24.3%) and the bimagrumab combination group (-25.5%). Moreover, the combination significantly improved body composition, reducing fat mass percentage by 77.8% (vs. 65.0% in the bimagrumab combination group) and increasing the lean-to-body weight ratio to 67.3% (vs. 62.3%), demonstrating superior fat loss with better preservation of lean mass. Collectively, these findings establish AB130-165 as a differentiated anti-ActRII antibody that enables high-quality weight loss, and its combination with semaglutide shows superior efficacy over bimagrumab-based regimens. With favorable developability and potential for long-acting subcutaneous administration, AB130-165 represents a promising next-generation therapeutic candidate for obesity and muscle-sparing weight management.

Background: Diabetes mellitus is an increasing public health challenge in Sierra Leone, where access to diagnosis, treatment, and long-term care remains limited. Traditional medicine continues to play a significant role in disease management; however, ethnobotanical knowledge related to diabetes remains insufficiently documented. Methods: A cross-sectional ethnobotanical survey was conducted among 40 informants, including traditional healers, herbalists, and knowledgeable community members in Waterloo, Pendembu, and Bo. Data were collected using structured questionnaires administered via Kobo Toolbox and paper-based tools. Information on medicinal plants, plant parts used, preparation methods, routes of administration, and knowledge transmission pathways was obtained. Quantitative ethnobotanical indices, including Frequency of Citation (FC), Relative Frequency of Citation (RFC), and Informant Consensus Factor (ICF), were calculated. Results: A total of 21 medicinal plant species were documented. The most frequently cited species were Moringa oleifera (FC = 9; RFC = 0.225), Vernonia amygdalina (FC = 7; RFC = 0.175), and both Cassia siberiana and Telfairia occidentalis (FC = 6; RFC = 0.150). Leaves were the most commonly utilized plant part (40.9%), and decoction was the predominant preparation method (76.2%), with oral administration accounting for 95.2% of use. The Informant Consensus Factor (ICF = 0.69) indicated a relatively high level of agreement among informants. Knowledge was primarily transmitted through apprenticeship and inherited family practices. Conclusion: Traditional medicinal plants remain an important component of diabetes management in Sierra Leone. The high level of consensus among informants and the repeated citation of specific plant species suggest structured and culturally validated therapeutic practices. The findings provide a foundation for future phytochemical and pharmacological investigations and highlight the need for documentation, preservation, and sustainable utilization of ethnobotanical knowledge.

1.Cancer-induced bone pain (CIBP) occurs in a majority of patients when primary or metastatic cancer develops within the bone. This pain has a significant impact on quality of life, yet there are limited effective treatment options available. Nerve sprouting is a complex mechanism that has been implicated in CIBP. Netrin-1 is a neuronal guidance molecule that is produced by numerous cell types, including cancer cells. In this study we aimed to determine whether netrin-1 inhibition (with NP137 - a humanized IGg1 monoclonal antibody) could ameliorate nerve sprouting, and nociception by extension, in three models of CIBP - osteosarcoma, metastatic breast cancer, and metastatic prostate cancer. Sustained administration of NP137 failed to produce an anti-nociceptive effect in these models, but a delayed onset was observed in the osteosarcoma model. NP137 did not produce a disease-modifying effect, as micro-computed tomography did not reveal reduced bone destruction in the NP137-treated groups. Additionally, there was no nerve fibre density reduction in any of the groups at the late-stage of the disease, suggesting that nerve sprouting occurs in early- to mid-stage CIBP development. Investigation of NP137 exposure indicated that serum levels of NP137 were comparable between the sham and cancer groups. Our study indicates that netrin-1 may play a role in early-stage CIBP development, but inhibition of this mechanism does not produce robust anti-nociception.

Background: Retrieval of adverse event reports based on coded drug-event co-occurrence enables large-scale pharmacovigilance analyses, but yields candidate reports rather than validated cases, risking misinterpretation if used alone. Aim: To develop and apply a framework for identification and characterization of clinically meaningful case series in pharmacovigilance. Methods: We conducted two case studies. The first developed and refined the framework in an information-rich setting, focusing on drug-induced impulsivity across selected drugs; the second tested its applicability in a more routine, information-poor setting, focusing on drug-induced suicidality. Results: In Case 1, non-relevant reports were frequent for drugs with uncertain evidence and negative controls ({approx}20-40%) compared to drugs with established causal roles (4%). The emerging framework assessed relevance based on exposure, event, drug-event relationship, and population. For suspected adverse drug reactions, relevant reports were further characterized by reporter suspicion and evidentiary qualifiers supporting or refuting causality; higher suspicion was associated with more supportive qualifiers. Applied to Case 2, the framework ruled out 69% of reports as non-relevant but highlighted substantial non-assessability (17%). Conclusions: In pharmacovigilance, retrieval is not equivalent to case identification. Relevance is question-specific and shaped by how reports are captured, processed, and retrieved. This can be especially critical for emerging or bias-prone safety questions. Transparent and reproducible case definition and adjudication are essential for interpretable analyses.

Introduction: Conventional substance-level disproportionality analysis may miss safety patterns specific to a dose form, route, or intended site. More granular analyses are hindered by incomplete, inconsistent reporting of product information. The Pharmaceutical Product Identifier (PhPID), representing products by substance, strength, and dose form, may support more granular analyses. Objective: To explore the use of PhPID-like dose form information for site-specific disproportionality analysis in dexamethasone. Methods: We evaluated VigiBase reports (January 1, 2001 - December 31, 2024) for completeness of dose form and route data. We standardized dexamethasone entries to PhPID Level 3 standards, representing substance and administrable dose form. Through disproportionality analysis (Information Component, IC) we compared substance-level and site-specific results. Results: Among 56.4 million suspected/interacting drugs, dose form was reported in 47.7%, route in 69.4%. Among 109,248 dexamethasone entries, 703 dose form and 80 route variations were mapped to 53 and 44 standard codes respectively; about half could be mapped unambiguously. Site-specific analyses revealed biologically plausible patterns not apparent in substance-level analyses. Ocular use showed higher ICs for glaucoma and cataract, while systemic use showed higher IC for psychiatric and endocrine events (e.g., depression, agitation, Cushing's syndrome). IC time-trends suggested that some signals (e.g., cataract with Ocular use) could emerge earlier in site-specific analyses. Conclusion: More granular product information, aligned with PhPID, may improve signal detection and characterization of site-specific safety issues. These findings support granular identifiers in pharmacovigilance while highlighting the need for better capture and standardization of dose form and route of administration data.

Background. Compounded tirzepatide is prescribed at scale as a cheaper substitute for branded Mounjaro and Zepbound, yet the cost case is almost always built by setting one compounded price against one branded list price. That framing ignores the question that actually decides the answer: cheaper than which branded price the patient can reach. Branded tirzepatide is now sold at sharply different tiers, namely insurance copay (often $25-$150/month), LillyDirect Self Pay ($299-$449/month), and retail cash price ($1,000-$1,200/month). Whether compounded saves money turns entirely on which of these a given patient faces. A second open question is whether the two formulations even produce comparable effectiveness, since observed differences may reflect selection on insurance, baseline characteristics, and adherence rather than the drug. Methods. We conducted a retrospective cohort study of tirzepatide users in the Mochi Health telehealth program, classified by formulation from their refills as branded-only (Mounjaro/Zepbound; 6,238), compounded-only (71,683), or switchers (4,996); switchers were excluded from the formulation contrast. Among single-formulation patients with a documented six-month weight observation, the analytic cohort was 7,271 (869 branded, 6,402 compounded). The primary outcome was six-month percent body weight loss; the secondary outcome was >=10% response. We used 1:1 nearest-neighbor propensity-score matching (0.25 SD caliper) on baseline covariates only - age, sex, baseline BMI, baseline weight, comorbid diabetes, hypertension, dyslipidemia, prior bariatric surgery, and self-reported insurance coverage - deliberately excluding post-treatment variables such as adherence and time in program, which are mediators of the formulation effect. We pre-specified an equivalence margin of +/-2 percentage points on mean loss and tested equivalence with two one-sided tests (TOST). A directed acyclic graph (DAG) makes the identifying assumptions explicit; metformin use could not be reliably ascertained and is treated as an unmeasured confounder. The cost comparison reports the savings or premium of compounded versus branded under five branded price scenarios: retail list, LillyDirect Self Pay (two dose tiers), and insurance copay (typical and low end). It is a cost comparison (cost-minimization under demonstrated similar effectiveness), not a formal cost-effectiveness analysis: we computed no ICER, QALY, or discounting. Results. Branded and compounded patients had similar outcomes even before adjustment (mean loss 11.7% vs 11.5%; >=10% response 60.9% vs 58.8%). The largest baseline difference between the groups was insurance coverage (branded patients far more likely insured; standardized mean difference 0.67), which matching balanced to 0.01. After 1:1 matching (718 pairs, all |SMD| < 0.04), mean loss was 11.4% vs 11.4% (difference +0.08 pp, 95% CI -0.70 to +0.80) and >=10% response 59.3% vs 57.2% (difference +2.1 pp, 95% CI -3.1 to +7.1). The two formulations were statistically equivalent within the pre-specified +/-2 pp margin (TOST p < 0.001). Cost depends on the branded scenario: compounded saves $6,000 over six months versus retail list price, $1,494 versus LillyDirect maintenance-dose (5-15 mg) Self Pay, and $594 over a low-dose (2.5 mg) LillyDirect prescription, while it costs $300 more than branded under a typical insurance copay ($150/month) and is more expensive still at lower copays (savings turn negative below $200/month). Conclusions. Branded and compounded tirzepatide were statistically equivalent in six-month effectiveness within a pre-specified +/-2 pp margin, so the choice between them is essentially a cost decision - and that cost advantage is real but conditional on the branded price the patient can access. It is large against retail list price and shrinks to zero or reverses against LillyDirect Self Pay or a low insurance copay. Whether compounded is the lower-cost choice for an individual patient is, therefore, a question about which price tier that patient faces.

Background. Polypharmacy is an important source of phenoconversion caused by drug interactions potentially modulated by genetic variability. Aims. To develop a linear phenoconversion model for TDM data and provide quantitative estimates of drug-drug-gene interactions (DDGIs) in the pharmacogenetic phenotype groups of CYP2C19. Methods. Escitalopram TDM data in a large real-world sample (n=2,852) was analysed for phenoconversion of CYP2C19 activity. Co-medication was identified by reprocessing high-resolution mass-spectra (Orbitrap). We developed a statistical model to identify inhibition from co-medication in the CYP2C19 and in alternative elimination pathways. We extended the model to estimate the inhibition ensuing from individual co-medications, using a single model for all data to account for multiple co-medications and confounders simultaneously. A Bayesian approach allowed us to stabilize the fit and provide well-calibrated credibility intervals. Results. Reprocessing of TDM analyses identified 17 co-medications, which were shown to phenoconvert CYP2C19 activity proportionally to the activity in non-medicated phenotypes. Phenoconversion decreased the original CYP2C19 activity by about one third for a co-medication that corresponded to a 100% substrate of CYP2C19. The extent of CYP2C19 phenoconversion correlated strongly with the fractional contribution of CYP2C19 to the metabolism of the specific co-medication reported in the pharmacogenetic literature (R2=0.55) so long as the mechanism was competitive inhibition. Conclusion. We provide the statistical methodology to estimate phenoconversion from co-medication in TDM data and combine TDM and pharmacogenetic datasets in future studies aiming at establishing quantitative models of DDGIs.

Hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitors are widely used for the treatment of renal anemia; however, their effects on intraocular vascular endothelial growth factor (VEGF) expression remain unclear. In this study, we examined the effects of all five HIF-PH inhibitors --roxadustat, daprodustat, vadadustat, enarodustat, and molidustat--on Vegfa expression in the retina in mice. C57BL/6J mice were orally administered each inhibitor. Six hours after administration, the kidney, retina, and liver were collected, and transcription levels were quantified by real-time quantitative reverse transcription PCR. Renal Epo transcription was significantly increased by molidustat (P < 0.01), roxadustat (P < 0.01), and enarodustat (P < 0.05). Retinal Vegfa transcription was significantly increased by four inhibitors (P < 0.01), with molidustat showing no significant effect. In the liver, Vegfa transcription was increased by daprodustat (P < 0.05) and vadadustat (P < 0.01). Furthermore, renal Epo and retinal Vegfa transcription levels showed a moderate positive correlation with a marginal trend toward statistical significance (r = 0.37, P = 0.08). These findings indicate that HIF-PH inhibitors differentially regulate hypoxia-responsive genes across tissues and suggest that retinal VEGF upregulation should be considered when evaluating the safety of these agents.

Background Thoracoscopic esophagectomy with intrathoracic carbon dioxide insufflation and lung collapse, usually performed in the prone position, can markedly alter respiratory physiology and acid-base balance. Serum potassium elevation is often observed during acute respiratory acidosis in these procedures, despite the conventional view that respiratory acidosis has little effect on potassium. We quantified the intraoperative potassium change and explored associated factors. Methods This multicenter retrospective study included adults undergoing thoracoscopic esophagectomy with carbon dioxide insufflation in the prone or lateral decubitus position during 2022-2024. Arterial blood gas variables were evaluated after anesthesia induction and at the time of the lowest arterial pH during carbon dioxide insufflation. The primary outcome was the paired difference in serum potassium. Sensitivity, subgroup, and regression analyses were performed. Results All 131 patients were included: 117 in the prone position and 14 in the lateral decubitus position. Serum potassium increased from 3.96 {+/-} 0.38 to 4.59 {+/-} 0.63 mEq/L (mean increase, 0.64 mEq/L; 95% confidence interval, 0.55-0.73; p < 0.001). During the same period, pH decreased from 7.387 to 7.247 and arterial carbon dioxide tension increased from 41.48 to 58.60 mmHg. After excluding marked metabolic acidosis, the increase remained significant and similar in magnitude (0.618 mEq/L). In the centered multivariable model, lactate change was independently associated with potassium change ({beta} = 0.303; p = 0.004), whereas arterial carbon dioxide change and preoperative renal function were not. The intercept remained significantly positive. Conclusions A clinically meaningful potassium increase was observed during thoracoscopic esophagectomy with carbon dioxide insufflation, while acute respiratory acidosis developed during the same period. The increase persisted after excluding marked metabolic acidosis and may not be explained solely by metabolic stress. Arterial blood gas assessment, including potassium measurement, is warranted during significant hypercapnia, and potential electrolyte consequences should be considered when permissive hypercapnia is accepted.

IntroductionThe quality of preclinical studies for rare diseases, such as Duchenne muscular dystrophy (DMD), relies on the availability of comprehensive natural disease history data. In addition to the classic BL10-mdx mouse, in recent years, the D2-mdx model has increasingly been used as an alternative model due to its reportedly more severely impaired phenotype. To improve our understanding of disease progression in these two DMD models, we conducted a comprehensive natural history study. Materials and MethodsThis involved a cross-sectional analysis of key in vivo and ex vivo outcome measures performed in two independent laboratories, using the same study setup in compliance with TREAT-NMD Standard Operating Procedures (SOPs), while also taking advantage of site-specific expertise. Globally, largely comparable results were obtained across the two study sites. ResultsBody composition showed pronounced differences between the strains, with BL10-mdx mice displaying a hypertrophic and D2-mdx mice displaying an atrophic phenotype. Dystrophic mice of each strain exhibited significant alterations of disease-relevant indices related to muscle functionality and integrity, mostly worsening with age, in comparison to their wildtypes. Cardiac function was affected earlier and more severely in D2-mdx mice. DiscussionNotably, for some parameters, genetic-background related differences were observed, emphasizing the need to include control groups with matching genetic backgrounds in experimental designs. ConclusionsCollectively, our natural history study provides benchmark data for these two mdx mouse strains to guide model selection for preclinical DMD studies, allowing accurate data interpretation. HighlightsO_LIDistinct body composition phenotypes: BL10-mdx mice exhibit pseudohypertrophy while D2-mdx mice display pronounced atrophy. C_LIO_LIEarlier cardiac dysfunction in D2-mdx: D2-mdx mice develop reduced ejection fraction and stroke volume from 28 weeks, while BL10-mdx only at 52 weeks. C_LIO_LIGenetic background-dependent variations: Intrinsic deficits in wildtype D2 mice demonstrate that genetic background influences outcome measures independent of dystrophic pathology. C_LIO_LIComparable ex vivo muscle physiology: Despite divergent in vivo phenotypes, isolated muscle contractile parameters show similar impairment in both dystrophic models. C_LIO_LIMulti-site standardized validation: Cross-sectional study at two independent laboratories following harmonized TREAT-NMD Standard Operating Procedures. C_LI

Neural stem cell (NSC) transplantation is a promising strategy for repairing the injured spinal cord, but transplanted cells typically require immunosuppressive therapy to prevent rejection, even for induced pluripotent stem cell (iPSC)-derived autologous grafts. However, the effects of immunosuppressive drugs on neurite outgrowth and axonal regeneration, processes critical for neural circuit reconstruction, have not been fully characterized. In this study, we tested nine clinically relevant immunosuppressants on human iPSC-derived neurons and primary human spinal cord NSCs in vitro at concentrations approximating clinical exposure levels. The drug panel included FK-506 (tacrolimus), cyclosporine A (CsA), rapamycin, belatacept (Nulojix), etanercept (Enbrel), mycophenolate mofetil (CellCept), cyclophosphamide (Cytoxan), prednisone, and azathioprine (Imuran). Neurite outgrowth was quantified via automated high-content imaging. Multiple agents, including CsA, Imuran, Nulojix, and CellCept, induced significant reductions in neurite outgrowth in a cell type- and dose-dependent manner, with CsA producing the most robust and consistent inhibition across both cell lines. In contrast, FK-506 showed no significant effect on neurite extension at clinically relevant concentrations. Consistent with the in vitro results, human neural progenitor cell grafts in a rodent spinal cord injury model exhibited significantly reduced graft-derived axon extension in the host spinal cord when hosts were treated with CsA rather than FK-506. These findings demonstrate that immunosuppressant choice can profoundly influence neural graft integration and axonal regeneration. Our study underscores the importance of preclinical evaluation of immunosuppressive regimens and suggests that selecting agents such as FK-506 over CsA may improve outcomes in future stem cell-based therapeutic trials for spinal cord injury and related disorders of the central nervous system.

BackgroundExtracellular matrix (ECM) remodeling is increasingly recognized as an important component of neuroinflammatory pathology in multiple sclerosis (MS), yet the mechanisms by which CNS cells sense and respond to alterations in their mechanical environment and the spatial across which mechanical changes can influence cellular behavior remain poorly understood. Piezo1 is a mechanosensitive ion channel that regulates cellular responses to mechanical stimuli and has recently emerged as a potential modulator of neuroinflammation. MethodsExperimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6 wildtype mice using myelin oligodendrocyte glycoprotein (MOG):35-55. Immunohistochemical analyses were performed in spinal cord gray matter (GM), normal-appearing white matter (NAWM), and white matter lesion (LES) regions to assess ECM remodeling, total Piezo1 expression, and astrocyte-specific Piezo1 expression during acute and chronic EAE stages. Correlations with clinical EAE severity were determined. In parallel, mixed primary murine glial cultures were exposed to substrates of different stiffness and analyzed by transcriptomic profiling to investigate mechanobiological responses in vitro. ResultsECM-associated proteins, including glial fibrillary acidic protein (GFAP), fibronectin-1 and matrix metalloproteinase-3 (MMP3), were regionally upregulated during EAE, indicating widespread tissue remodeling beyond focal inflammatory lesions. Total Piezo1 expression was increased within lesions and transiently elevated in GM, whereas astrocyte-specific Piezo1 remained persistently upregulated during both acute and chronic EAE. Astrocytic Piezo1 expression correlated closely with ECM remodeling and clinical EAE severity, particularly in GM and NAWM. Notably, both total and astrocyte-specific Piezo1 showed stronger associations with clinical disability than classical inflammatory markers. Transcriptomic analysis revealed pronounced stiffness-dependent responses in glial cells, including alterations in extracellular matrix organization, cytokine signaling, cell adhesion, and proliferative pathways. ConclusionsOur findings identify astrocytic Piezo1 as a prominent component of neuroinflammatory tissue remodeling during EAE. The close association of Piezo1 with ECM alterations, clinical disease severity, and stiffness-dependent glial responses supports a link between neuroinflammation and mechanosensory signaling. These results highlight mechanosensation as a potentially important contributor to CNS pathology and establish Piezo1 alteration as a candidate biomarker for neuroinflammatory disease.

Multiple sclerosis (MS), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and neuromyelitis optica spectrum disorder (NMOSD) are immune-mediated inflammatory disorders of the central nervous system (CNS). The temporal relationship between disease-specific autoantibodies and biomarkers of CNS injury before diagnosis remains unclear and is relevant for understanding early pathobiology. Here, we conducted a multicentre retrospective longitudinal case-control study using prediagnostic plasma from 362 individuals who later developed MS, 145 who developed MOGAD, and 60 who developed NMOSD. Plasma IgG levels against CNS antigens, MOG, and AQP4, as well as neurofilament light chain (pNfL), were quantified, and temporal relationships between immune activation, neuroaxonal injury, and clinical disease onset were modelled using linear mixed-effects models and survival analyses. In MS, EBNA-1-specific and CNS-cross-reactive IgG were elevated up to 77.8 months before diagnosis, preceding pNfL increases by 44.9 months. In NMOSD, AQP4-IgG seroconversion occurred 32.5 months before diagnosis and preceded pNfL elevations by 40.4 months. In MOGAD, pNfL elevations preceded MOG-IgG seroconversion by 11.2 months. Thus, in MS and NMOSD, humoral autoimmunity precedes detectable CNS injury, whereas in MOGAD, neuroaxonal injury occurs before circulating MOG-IgG. These distinct temporal patterns suggest differing early immunopathological trajectories and may provide a framework for future studies of early disease biology and biomarker-guided risk stratification.