Intravenous Versus Subcutaneous Infliximab in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Subcutaneous (SC) infliximab may provide multiple benefits over intravenous (IV) formulations. However, studies for efficacy and safety in inflammatory bowel disease (IBD) have been constrained by small sizes that limit the interpretation of outcomes, especially for subgroups potentially at high-risk of disease relapse. METHODS: We conducted a systematic review and random-effects meta-analysis up to January 2023 to evaluate the change in clinical remission after transitioning from IV to SC infliximab in patients with IBD in clinical remission. The primary outcome was measured using the relative risk for meta-analysis. RESULTS: 15 studies of patients established ≥3 months on IV infliximab were identified, consisting of 1371 patients and 840 patient-years of follow-up. There was no loss of clinical remission in the IBD cohort overall, Crohn's disease (CD), and perianal CD p=0.55 & p=0.11 at 9-12 months, and p=0.50 at 6 months respectively). Neither prior IV dose (≤10mg/kg 6-weekly) (p=0.48) nor IBD disease subtype was associated with an increased clinical relapse rate at 6 months (p=0.48 and p=0.45 (UC vs CD), respectively). CONCLUSION: Changing patients established on IV infliximab to an SC formulation is associated with a high ongoing clinical remission and low adverse event rate. Furthermore, there are no signals for adverse outcomes among different IBD disease subtypes, nor in those on escalated IV infliximab dosing schedules up to 10mg/kg 6-weekly. This data should provide patients and clinicians alike with confidence in SC infliximab use in IBD.

Comparative efficacy and safety of subcutaneous infliximab and vedolizumab in patients with Crohn's disease and ulcerative colitis included in randomised controlled trials.

BACKGROUND: While indirect comparison of infliximab (IFX) and vedolizumab (VDZ) in adults with Crohn's disease (CD) or ulcerative colitis (UC) shows that IFX has better effectiveness during induction, and comparable efficacy during maintenance treatment, comparative data specific to subcutaneous (SC) IFX (i.e., CT-P13 SC) versus VDZ are limited. AIM: Pooled analysis of randomised studies to compare efficacy and safety with IFX SC and VDZ in moderate-to-severe inflammatory bowel disease. METHODS: Parallel-group, randomised studies evaluating IFX SC and VDZ in patients with moderate-to-severe CD or UC were identified. Eligible studies reported ≥ 1 prespecified outcome of interest at Week 6 (reflecting treatment during the induction phase) and/or at 1 year (Weeks 50-54; reflecting treatment during the maintenance phase). Prespecified efficacy and safety outcomes considered in this pooled analysis included the proportions of patients achieving disease-specific clinical responses, clinical remission, or discontinuing due to lack of efficacy, and the proportions of patients experiencing adverse events (AEs), serious AEs, infections, serious infections, or discontinuing due to AEs. Data from multiple studies or study arms were extracted and pooled using a random-effect model; comparative analyses were performed separately for patients with CD and UC. RESULTS: We identified three eligible CD trials and four eligible UC trials that assigned over 1200 participants per disease cohort to either IFX SC or VDZ. In patients with CD, intravenous induction therapy with IFX demonstrated better efficacy (non-overlapping 95% confidence intervals [CIs]) compared with VDZ; during the maintenance phase, IFX SC showed numerically better efficacy (overlapping 95% CIs) than VDZ. A lower proportion of IFX SC-treated patients discontinued therapy due to lack of efficacy over 1 year. In patients with UC, efficacy profiles were similar with IFX SC and VDZ during the induction and maintenance phases, and a lower proportion of IFX SC-treated patients discontinued therapy due to lack of efficacy over 1 year. In both cohorts, safety profiles for IFX SC and VDZ were generally comparable during 1 year. CONCLUSION: IFX SC demonstrated better efficacy than VDZ in patients with CD, and similar efficacy to VDZ in patients with UC; 1-year safety was comparable with IFX SC and VDZ.

Top 10 research priorities for digital technology for adolescents and young persons with inflammatory bowel disease: Results of a James Lind Alliance Priority Setting Partnership.

OBJECTIVES: Priority Setting Partnerships (PSP's) using the James Lind Alliance (JLA) methodology, bring together health professionals, patients and parents/carers to identify and prioritise unanswered questions that can be addressed by future research projects. To identify and prioritise the top 10 unanswered research priorities in digital technology for adolescents and young people (AYP) with inflammatory bowel disease (IBD). METHODS: A steering group (SG) consisting of AYP with IBD, their parents/carers, representatives from two charities (Crohn's & Colitis UK, Crohn's in Childhood Research Association), patient information forum and paediatric and adult and primary care healthcare professionals was established in 2021. The SG agreed the protocol, and scope of the PSP and oversaw all aspects. SG meetings were chaired by a JLA advisor and followed the established JLA methodology. RESULTS: The initial survey generated 414 in-scope questions from 156 respondents, thematically categorised into 10 themes and consolidated into 92 summary questions by the SG. A comprehensive literature review followed by SG deliberation narrowed the unanswered summary questions to 45, for the interim prioritising survey. One hundred and two respondents ranked their top 10 research questions. Outputs generated top 18 research priorities presented at a final virtual prioritisation workshop, facilitated by JLA advisors and attended by key stakeholders, ranked into top 10 research priorities. DISCUSSION: The top 10 research priorities will encourage researchers to undertake research that addresses these areas of unmet need for AYP living with IBD, their parents/carers and their healthcare professionals, thereby facilitating improved patient care.

Nurse-led approach to standardising the management of iron-deficiency anaemia, achieving the 2-week cancer pathway targets and reducing hospital admissions: practicalities and learnings from a success story.

The most significant and common cause of anaemia is iron deficiency, which occurs when iron absorption cannot meet the body's demands due to growth, pregnancy, poor nutrition, malabsorption or blood loss. It is estimated that in the UK 11% of the adult population have iron-deficiency anaemia (IDA) and investigation is essential to exclude significant pathology as the underlying cause. It has been shown that IDA is responsible for 57 000 hospital admissions in the UK, and at least 10% of gastroenterology referrals per annum. IDA is a major red flag symptom for gastrointestinal cancer. At the Royal Liverpool University Hospital, a dedicated nurse-led IDA service was developed in 2005 to help alleviate the clinical pressures created by the two week suspected cancer referral pathway. With the success of this service, investigation and management of IDA has been extended to referrals from accident and emergency, with the aim of reducing hospital admissions and to investigating and optimising iron replacement therapy in preoperative patients. Delivering this as a nurse consultant-led service was proposed by the gastroenterology medical team who felt that, as a clinical problem with well established, published investigative algorithms, IDA would be suitable for management in a dedicated nurse-led clinic. This article will focus on the strategies employed to achieve sufficient resources and clinic capacity to run this service effectively, develop strong nurse education and training, and the development of agreed investigation pathways. A robust results review process, with rapid management of abnormal results, was established with timely discharge for those patients with normal results. Optimisation of iron replacement therapy and verification of sustained haematological response was prioritised as this was identified as being poorly managed across all specialties. A process for ongoing audit of results was included to show the success of the service and highlight areas for redesign. Here, we demonstrate the effectiveness of our nurse-led IDA service and suggest it as the basis for other IDA services in the UK and beyond.

Laparoscopic surgery for adrenocortical carcinoma: Estimating the risk of margin-positive resection.

BACKGROUND: Over recent years, there has been increasing adoption of minimally invasive surgery (MIS) in the treatment of adrenocortical carcinoma (ACC). However, MIS has been associated with noncurative resection and locoregional recurrence. We aimed to identify risk factors for margin-positivity among patients who undergo MIS resection for ACC. We hypothesized that a simple nomogram can accurately identify patients most suitable for curative MIS resection. METHODS: Curative-intent resections for ACC were identified through the National Cancer Database spanning 2010-2018. Trends in MIS utilization were reported using Pearson correlation coefficients. Factors associated with margin-positive resection were identified among preoperatively available variables using multivariable logistic regression, then incorporated into a predictive model. Model quality was cross validated using an 80% training data set and 20% test data set. RESULTS: Among 1260 ACC cases, 38.6% (486) underwent MIS resection. MIS utilization increased over time at nonacademic centers (R = 0.818, p = 0.007), but not at academic centers (R = 0.009, p = 0.982). Factors associated with margin-positive MIS resection were increasing age, nonacademic center (odds ratio [OR]: 1.8, p = 0.006), cT3 (OR: 4.7, p < 0.001) or cT4 tumors (OR: 14.6, p < 0.001), and right-sided tumors (OR: 2.0, p = 0.006). A predictive model incorporating these four factors produced favorable c-statistics of 0.75 in the training data set and 0.72 in the test data set. A pragmatic nomogram was created to enable bedside risk stratification. CONCLUSIONS: An increasing proportion of ACC are resected via minimally invasive operations, particularly at nonacademic centers. Patient selection based on a few key factors can minimize the risk of noncurative surgery.

Omics Analysis and Quality Control Pipelines in a High-Performance Computing Environment.

Data quality is often an overlooked feature in the analysis of omics data. This is particularly relevant in studies of chemical and pathogen exposures that can modify an individual's epigenome and transcriptome with persistence over time. Portable, quality control (QC) pipelines for multiple different omics datasets are therefore needed. To meet these goals, portable quality assurance (QA) metrics, metric acceptability criterion, and pipelines to compute these metrics were developed and consolidated into one framework for 12 different omics assays. Performance of these QA metrics and pipelines were evaluated on human data generated by the Defense Advanced Research Projects Agency (DARPA) Epigenetic CHaracterization and Observation (ECHO) program. Twelve analytical pipelines were developed leveraging standard tools when possible. These QC pipelines were containerized using Singularity to ensure portability and scalability. Datasets for these 12 omics assays were analyzed and results were summarized. The quality thresholds and metrics used were described. We found that these pipelines enabled early identification of lower quality datasets, datasets with insufficient reads for additional sequencing, and experimental protocols needing refinements. These omics data analysis and QC pipelines are available as open-source resources as reported and discussed in this article for the omics and life sciences communities.

Molecular landscape and functional characterization of centrosome amplification in ovarian cancer.

High-grade serous ovarian carcinoma (HGSOC) is characterised by poor outcome and extreme chromosome instability (CIN). Therapies targeting centrosome amplification (CA), a key mediator of chromosome missegregation, may have significant clinical utility in HGSOC. However, the prevalence of CA in HGSOC, its relationship to genomic biomarkers of CIN and its potential impact on therapeutic response have not been defined. Using high-throughput multi-regional microscopy on 287 clinical HGSOC tissues and 73 cell lines models, here we show that CA through centriole overduplication is a highly recurrent and heterogeneous feature of HGSOC and strongly associated with CIN and genome subclonality. Cell-based studies showed that high-prevalence CA is phenocopied in ovarian cancer cell lines, and that high CA is associated with increased multi-treatment resistance; most notably to paclitaxel, the commonest treatment used in HGSOC. CA in HGSOC may therefore present a potential driver of tumour evolution and a powerful biomarker for response to standard-of-care treatment.

Young persons and healthcare professionals experience of virtual gastroenterology consultations: a multicentre survey conducted during the COVID-19 pandemic.

Objective: To explore Young Persons (YP) and healthcare professionals (HCP) experiences of virtual consultations (VC) and establish whether developmentally appropriate healthcare can be delivered virtually. Method: YP and HCP questionnaire surveys were designed and piloted. Electronic questionnaire links were sent by post, email or text message January-April 2021 to YP aged 13-25 years old, with predefined chronic gastrointestinal conditions, attending a gastroenterology/hepatology VC. HCP undertaking VC were invited to complete staff questionnaire. Results were anonymous and collated using Excel version 2302. Results: Five UK hospital trusts participated, with 35 HCP responses. Of the 100 YP completing the survey 66% were female and 34% male aged between 13 years and 25 years (median: 18 years). 13% were new appointments and 87% follow ups, 29% were by video, 69% by phone and 2% gave no response. 80% of HCP spoke to YP directly but not privately (69%). 87% of YP and 88% HCP found VC useful. 83% of YP want VC again, although 20% preferred face to face. 43% of HCP required improved phone/internet connection. 77% of YP required hospital appointments for tests following VC. Conclusions: Overall respondents were satisfied with VC, finding them useful, convenient and time saving. Successful VC rely on appropriate patient selection and availability of reliable technology. Patient preference is key which may alter with time.

Advancing Proficiencies for Health Professionals in the Treatment of Tobacco Use Among Marginalized Communities: Development of a Competency-Based Curriculum and Virtual Workshop.

BACKGROUND: Tobacco-related disparities are a leading contributor to health inequities among marginalized communities. Lack of support from health professionals is one of the most cited barriers to tobacco cessation reported by these communities. Improving the proficiencies with which health professionals incorporate social and cultural influences into therapeutic interactions has the potential to address this critical barrier. In general, training to improve these proficiencies has shown promise, but the specific proficiencies required for treating tobacco use among marginalized communities are unknown. This project aimed to develop a competency-based curriculum to improve these proficiencies among health professionals with experience and training in the evidence-based treatment of tobacco use, and then pilot test the content delivered via an expert review of a virtual, self-paced workshop. METHODS: We used the Delphi Technique to systematically identify the specific competencies and corresponding knowledge and skill sets required to achieve these proficiencies. Educational content was developed to teach these competencies in a virtual workshop. The workshop was evaluated by 11 experts in the field by examining pre- and post-training changes in perceived knowledge, skill, and confidence levels and other quantitative and qualitative feedback. Repeated measures analysis of variance and paired sample t-tests were used to examine pre-post training differences. RESULTS: Six competencies and corresponding skill sets were identified. After exposure to the virtual workshop, the experts reported significant increases in the overall proficiency for each competency as well as increases in nearly all levels of knowledge, skill, and confidence within the competency skill sets. Qualitative and quantitative findings indicate that content was relevant to practice. CONCLUSIONS: These findings provide preliminary support for 6 competencies and skills sets needed to improve therapeutic interpersonal interactions that recognize the importance of social and cultural influences in the treatment of tobacco use.

Aldehyde oxidase 1 activity and protein expression in human, rabbit, and pig ocular tissues.

Aldehyde oxidase (AOX) is a cytosolic drug-metabolizing enzyme which has attracted increasing attention in drug development due to its high hepatic expression, broad substrate profile and species differences. In contrast, there is limited information on the presence and activity of AOX in extrahepatic tissues including ocular tissues. Because several ocular drugs are potential substrates for AOX, we performed a comprehensive analysis of the AOX1 expression and activity profile in seven ocular tissues from humans, rabbits, and pigs. AOX activities were determined using optimized assays for the established human AOX1 probe substrates 4-dimethylamino-cinnamaldehyde (DMAC) and phthalazine. Inhibition studies were undertaken in conjunctival and retinal homogenates using well-established human AOX1 inhibitors menadione and chlorpromazine. AOX1 protein contents were quantitated with targeted proteomics and confirmed by immunoblotting. Overall, DMAC oxidation rates varied over 10-fold between species (human ˃˃ rabbit ˃ pig) and showed 2- to 6-fold differences between tissues from the same species. Menadione seemed a more potent inhibitor of DMAC oxidation across species than chlorpromazine. Human AOX1 protein levels were highest in the conjunctiva, followed by most posterior tissues, whereas anterior tissues showed low levels. The rabbit AOX1 expression was high in the conjunctiva, retinal pigment epithelial (RPE), and choroid while lower in the anterior tissues. Quantification of pig AOX1 was not successful but immunoblotting confirmed the presence of AOX1 in all species. DMAC oxidation rates and AOX1 contents correlated quite well in humans and rabbits. This study provides, for the first time, insights into the ocular expression and activity of AOX1 among multiple species.

Gold-Catalyzed Cyclization of Yndiamides with Isoxazoles via α-Imino Gold Fischer Carbenes.

Gold catalysis is an important method for alkyne functionalization. Here we report the gold-catalyzed formal [3+2] aminative cyclization of yndiamides and isoxazoles in a direct synthesis of polysubstituted diaminopyrroles, which are important motifs in drug discovery. Key to this process is the formation, and subsequent cyclization, of an α-imino gold Fischer carbene, which represents a new type of gold carbene intermediate. The reaction proceeds rapidly under mild conditions, with high regioselectivity being achieved by introducing a subtle steric bias between the nitrogen substituents on the yndiamide. DFT calculations revealed that the key to this regioselectivity was the interconversion of isomeric gold keteniminiun ions via a low-barrier π-complex transition state, which establishes a Curtin-Hammett scenario for isoxazole addition. By using benzisoxazoles as substrates, the reaction outcome could be switched to a formal [5+2] cyclization, leading to 1,4-oxazepines.

Bee Pollinator Mortality Due to Pesticide-Laden Particulate Matter from Beef Cattle Feedyards.

Wild and managed bees are critical for the stability of trophic webs, angiosperm reproduction, and agricultural productivity. Unfortunately, as many as 40% of crop pollinators are in a steep decline due to habitat loss and exposure to agrochemicals. Pyrethroids, neonicotinoids, and macrocyclic lactones are among the many agrochemicals toxic to pollinating insects that are used extensively in industrial beef cattle feeding operations throughout the world. Fugitive feedyard particulate matter (PM) transports agrochemicals into the surrounding environs. To determine the impact of agrochemical-laden feedyard particulate matter on bee pollinators, we conducted in situ experiments wherein honeybees and mason bees were placed downwind and upwind of feedyards (N = 40). Concurrent, colocated total suspended particulate matter samples contained multiple insecticides and parasiticides including pyrethroids, neonicotinoids, and macrocyclic lactones, in significantly higher concentrations downwind of feedyards (bifenthrin, 8.45 ± 4.92; permethrin, 1032.34 ± 740.76; clothianidin, 3.61 ± 1.48; imidacloprid, 73.32 ± 47.52; thiamethoxam, 5.81 ± 3.16; abamectin, 0.45 ± 0.29; ivermectin, 8.88 ± 5.06 ng/g). Honeybees and mason bees sited downwind of feedyards always experienced higher mortality than those correspondingly sited upwind, and male mason bees experienced significantly higher mortality compared to females when both were sited downwind. Bees occurring downwind of beef cattle feedyards for 1 h are 232-260% more likely to die than those occurring upwind. Thus, agrochemicals used on and emitted from beef cattle feedyards are significant threats to bee pollinators.

Laboratory Determination of Particulate-Matter-Bound Agrochemical Toxicity among Honeybees, Mason Bees, and Painted Lady Butterflies.

Pollinator population declines are global phenomena with severe consequences for native flora and agriculture. Many factors have contributed to pollinator declines including habitat loss, climate change, disease and parasitism, reductions in abundance and diversity of foraging resources, and agrochemical exposure. Particulate matter (PM) serves as a carrier of toxic agrochemicals, and pollinator mortality can occur following exposure to agrochemical-contaminated PM. Therefore, laboratory-controlled experiments were conducted to evaluate impacts of individual PM-bound agrochemicals. Honeybees (Apis mellifera), blue orchard mason bees (Osmia lignaria), and painted lady butterfly (Vanessa cardui) larvae were exposed to bifenthrin, permethrin, clothianidin, imidacloprid, abamectin, and ivermectin via suspended, airborne PM. Agrochemical concentrations in PM to which pollinators were exposed were based on concentrations observed in fugitive beef cattle feedyard PM including a "mean" treatment and a "max" treatment reflective of reported mean and maximum PM-bound agrochemical concentrations, respectively. In general, pollinators in the mean and max treatments experienced significantly higher mortality compared with controls. Honeybees were most sensitive to pyrethroids, mason bees were most sensitive to neonicotinoids, and painted lady butterfly larvae were most sensitive to macrocyclic lactones. Overall, pollinator mortality was quite low relative to established toxic effect levels derived from traditional pollinator contact toxicity tests. Furthermore, pollinator mortality resulting from exposure to individual agrochemicals via PM was less than that reported to occur at beef cattle feedyards, highlighting the importance of mixture toxicity to native and managed pollinator survival and conservation. Environ Toxicol Chem 2023;42:2642-2650. © 2023 SETAC.

Comparing different pneumoperitoneum (12 vs. 15 mmHg) pressures with cytokine analysis to evaluate clinical outcomes in patients undergoing robotic-assisted laparoscopic radical cystectomy and intracorporeal robotic urinary diversion.

Background: Robotic cystectomy is the mainstay surgical intervention for treatment-refractory nonmuscle-invasive and muscle-invasive bladder cancer. However, paralytic ileus may complicate the postoperative recovery and may be a consequence of an inflammatory response associated with transient gut ischaemia. We have therefore investigated clinical, operative and inflammatory biomarker associations between paralytic ileus in the context of robotic cystectomy and intracorporeal ileal conduit urinary diversion. Methods: Prospective consective patients referred for robotic cystectomy were consented and included in the study, while patients >75 years old and converted to open procedure were excluded. The pneumoperitoneum pressure (PP) for carbon dioxide insufflation required to perform the procedure efficiently and safely was recorded (12 or 15 mmHg). We also recorded the postoperative days patients passed flatus and stools, whether they developed ileus, as well as other standard clinical and demographic data. The expression of select proinflammatory and anti-inflammatory cytokines was determined by multiplex analysis using a cytometric bead array with changes in profiles correlated with the pressures applied and with the existence of an ileus. Results: Twenty-seven patients were recruited, but only 20 were used in the study with 10 patients in each PP group. Seven patients were excluded all of whom had an extracorporeal ileal conduit formation. There were differences in the 40-min shorter operative time and 1 day shorter length of stay, as well as passing flatus 1 day and stools 1.5 days earlier in the 12 mmHg compared with the 15 mmHg group. More patients had ileus in the 15 mmHg group vs 12 mmHg group (30% vs. 10.0%). These were not statistically significant. Similarly, there were no statistical differences in the expression of proinflammatory cytokines at the two different pressures or between patient groups, but there were outliers, with the median indicating nonsymmetrical distribution. By comparison, anti-inflammatory cytokines showed some significant differences between groups, with IL-6 and IL-10 showing elevated levels postsurgery. No statistical difference was observed between pressures or the existence of an ileus, but the maximum levels of IL-6 and IL-10 detected in some patients reflect a pressure difference. Conclusions: The initial findings of this novel scientific study indicated a higher risk of paralytic ileus postrobotic cystectomy and robotic intracorporeal urinary diversion when a higher pressure of 15 mmHg is used compared with 12 mmHg. Although further studies are required to establish the linkage between cytokine profile expression, pressure and ileus, our initial data reinforces the advantages of lower pressure robotic cystectomy and intracorporeal urinary diversion in patient outcomes.

The copy number and mutational landscape of recurrent ovarian high-grade serous carcinoma.

The drivers of recurrence and resistance in ovarian high grade serous carcinoma remain unclear. We investigate the acquisition of resistance by collecting tumour biopsies from a cohort of 276 women with relapsed ovarian high grade serous carcinoma in the BriTROC-1 study. Panel sequencing shows close concordance between diagnosis and relapse, with only four discordant cases. There is also very strong concordance in copy number between diagnosis and relapse, with no significant difference in purity, ploidy or focal somatic copy number alterations, even when stratified by platinum sensitivity or prior chemotherapy lines. Copy number signatures are strongly correlated with immune cell infiltration, whilst diagnosis samples from patients with primary platinum resistance have increased rates of CCNE1 and KRAS amplification and copy number signature 1 exposure. Our data show that the ovarian high grade serous carcinoma genome is remarkably stable between diagnosis and relapse and acquired chemotherapy resistance does not select for common copy number drivers.

Pregnancy related hormones increase CYP3A mediated buprenorphine metabolism in human hepatocytes: a comparison to CYP3A substrates nifedipine and midazolam.

Introduction: Pregnancy increases the clearance of CYP3A4 substrate drugs and pregnancy-related hormones (PRHs) induce hepatic CYP3A4 expression and metabolism. However, it remains unclear to what extent the magnitude of PRH-evoked changes in hepatic CYP3A metabolism varies across multiple substrates. This study quantified the impact of PRHs on CYP3A protein concentrations and buprenorphine metabolism in human hepatocytes, and compared the magnitude of these effects to nifedipine and midazolam metabolism. Methods: Sandwich-cultured human hepatocytes (SCHH) from female donors were exposed to PRHs, administered in combination across a range of physiologically relevant concentrations, for 72 h. Absolute protein concentrations of CYP3A4, CYP3A5, and CYP3A7 in SCHH membrane fractions were quantified by nanoLC-MS/MS, and norbuprenorphine (nor-BUP), dehydro-nifedipine (dehydro-NIF), and 1-hydroxy-midazolam (1-OH-MDZ) formation was evaluated. Results: Compared to control, PRH exposure increased CYP3A4, CYP3A7, and total CYP3A protein concentrations, but not CYP3A5 concentrations, and increased nor-BUP, dehydro-NIF, and 1-OH-MDZ formation in a concentration-dependent manner. The formation of nor-BUP, dehydro-NIF, and 1-OH-MDZ each positively correlated with PRH-mediated changes in total CYP3A protein concentrations. The PRH-evoked increase in nor-BUP formation was evident in all donors; however, the PRH induction of dehydro-NIF and 1-OH-MDZ formation was diminished in a hepatocyte donor with high basal CYP3A5 expression. Discussion: These findings demonstrate that PRHs increase buprenorphine, nifedipine, and midazolam metabolism in SCHH via induction of CYP3A4 and total CYP3A protein concentrations, and the magnitude of these effects vary across hepatocyte donors in a substrate-specific manner. These data provide insight into the contribution of PRH induction of CYP3A4 metabolism to increased buprenorphine clearance during pregnancy.