UV-Induced Spectral and Morphological Changes in Bacterial Spores for Inactivation Assessment.

The ability to detect and inactivate spore-forming bacteria is of significance within, for example, industrial, healthcare, and defense sectors. Not only are stringent protocols necessary for the inactivation of spores but robust procedures are also required to detect viable spores after an inactivation assay to evaluate the procedure's success. UV radiation is a standard procedure to inactivate spores. However, there is limited understanding regarding its impact on spores' spectral and morphological characteristics. A further insight into these UV-induced changes can significantly improve the design of spore decontamination procedures and verification assays. This work investigates the spectral and morphological changes to Bacillus thuringiensis spores after UV exposure. Using absorbance and fluorescence spectroscopy, we observe an exponential decay in the spectral intensity of amino acids and protein structures, as well as a logistic increase in dimerized DPA with increased UV exposure on bulk spore suspensions. Additionally, using micro-Raman spectroscopy, we observe DPA release and protein degradation with increased UV exposure. More specifically, the protein backbone's 1600-1700 cm-1 amide I band decays slower than other amino acid-based structures. Last, using electron microscopy and light scattering measurements, we observe shriveling of the spore bodies with increased UV radiation, alongside the leaking of core content and disruption of proteinaceous coat and exosporium layers. Overall, this work utilized spectroscopy and electron microscopy techniques to gain new understanding of UV-induced spore inactivation relating to spore degradation and CaDPA release. The study also identified spectroscopic indicators that can be used to determine spore viability after inactivation. These findings have practical applications in the development of new spore decontamination and inactivation validation methods.

Enolase represents a metabolic checkpoint controlling the differential exhaustion programmes of hepatitis virus-specific CD8+ T cells.

OBJECTIVE: Exhausted T cells with limited effector function are enriched in chronic hepatitis B and C virus (HBV and HCV) infection. Metabolic regulation contributes to exhaustion, but it remains unclear how metabolism relates to different exhaustion states, is impacted by antiviral therapy, and if metabolic checkpoints regulate dysfunction. DESIGN: Metabolic state, exhaustion and transcriptome of virus-specific CD8+ T cells from chronic HBV-infected (n=31) and HCV-infected patients (n=52) were determined ex vivo and during direct-acting antiviral (DAA) therapy. Metabolic flux and metabolic checkpoints were tested in vitro. Intrahepatic virus-specific CD8+ T cells were analysed by scRNA-Seq in a HBV-replicating murine in vivo model of acute and chronic infection. RESULTS: HBV-specific (core18-27, polymerase455-463) and HCV-specific (NS31073-1081, NS31406-1415, NS5B2594-2602) CD8+ T cell responses exhibit heterogeneous metabolic profiles connected to their exhaustion states. The metabolic state was connected to the exhaustion profile rather than the aetiology of infection. Mitochondrial impairment despite intact glucose uptake was prominent in severely exhausted T cells linked to elevated liver inflammation in chronic HCV infection and in HBV polymerase455-463 -specific CD8+ T cell responses. In contrast, relative metabolic fitness was observed in HBeAg-negative HBV infection in HBV core18-27-specific responses. DAA therapy partially improved mitochondrial programmes in severely exhausted HCV-specific T cells and enriched metabolically fit precursors. We identified enolase as a metabolic checkpoint in exhausted T cells. Metabolic bypassing improved glycolysis and T cell effector function. Similarly, enolase deficiency was observed in intrahepatic HBV-specific CD8+ T cells in a murine model of chronic infection. CONCLUSION: Metabolism of HBV-specific and HCV-specific T cells is strongly connected to their exhaustion severity. Our results highlight enolase as metabolic regulator of severely exhausted T cells. They connect differential bioenergetic fitness with distinct exhaustion subtypes and varying liver disease, with implications for therapeutic strategies.

Mass Balance and Absorption, Distribution, Metabolism, and Excretion Properties of Balcinrenone following Oral Administration in Combination with Intravenous Microtracer in Healthy Subjects.

An absorption, distribution, metabolism, and excretion study was performed to determine the basic pharmacokinetic parameters, mass balance, and metabolite profiles of balcinrenone, a mineralocorticoid receptor modulator, in humans. This open-label, single-center, nonrandomized study had a two-period design. In period 1, eight healthy male subjects were dosed with a microtracer intravenous infusion of [14C]balcinrenone shortly after receiving an oral dose of unlabeled balcinrenone in a capsule. Following a 7-day washout, the same group of subjects subsequently received an oral dose of [14C]balcinrenone as a suspension in period 2. Clearance and absolute bioavailability of balcinrenone were determined to be 14.2 l/h and 52%, respectively. Renal clearance was determined to be 5.4 l/h (>fu • glomerular filtration rate), indicating elimination via active tubular secretion, which was potentially mediated by P-glycoprotein 1 and/or organic anion transporter 3, according to in vitro transporter data. In total, 94.1% of the oral dose was recovered: 45.2% in the urine and 48.9% in the feces. Balcinrenone was primarily metabolized via oxidation, and in vitro data suggest that cytochrome P450 3A4 was the main enzyme responsible. Intact [14C]balcinrenone accounted for 55% of drug-related material in the plasma; four metabolites were identified, each representing <6% of the total plasma radioactivity. In conclusion, this two-period study has determined the basic pharmacokinetic parameters of balcinrenone in humans, including absolute bioavailability and disposition. No metabolites warranted further evaluation on account of their low representation, and any contribution to the pharmacodynamic response or potential drug-drug interactions was deemed negligible. SIGNIFICANCE STATEMENT: This study provides a detailed understanding of the pharmacokinetics, disposition, and metabolism of balcinrenone following oral and microtracer intravenous administration in humans. In vitro phenotyping and transporter data granted mechanistic insights into the absorption, distribution, metabolism, and excretion properties of balcinrenone. This knowledge will guide future nonclinical and clinical studies evaluating drug-drug interactions, organ dysfunction, and safety of metabolites.

A population study of textile fibres on the seats at three public venues.

A population study was carried out by collecting textile fibres present on the seats in a church, a cinema and a conference centre in Linköping, Sweden. The collection was carried out in such a way as to avoid inadvertent fibre collectives and to enable comparison of the frequency data between venues. In total 4220 fibres were examined and details of their characteristics were recorded and entered into a searchable database. Only coloured fibres over 0.5 mm in length were included in the study. 70% of the fibres were classified as cotton, 18% were man-made, 8% wool, 3% other plant and 2% other animal. Polyester and regenerated cellulose were the most abundant man-made fibres. The most frequently occurring combinations were blue and grey/black cotton, making up approximately 50% of all fibres. All other combinations were made up of less than 8% of the fibres, with red cotton being the next most prevalent. The results regarding the most frequently occurring fibre types, colours and colour/fibre type combinations are comparable to those of other population studies that have been carried out in different countries over the last 20-30 years. Additional observations regarding the frequency occurrence of certain characteristics are presented, such as differences in thickness, cross-sectional shape and presence of pigment or delustrant for the man-made fibre types.

Verinurad does not prolong QTc interval: a thorough QT study using concentration-QTc modelling.

AIM: This thorough QT/QTc (TQT) study was conducted to evaluate the risk of QT prolongation for verinurad when combined with allopurinol. Verinurad is a novel, urate anion exchanger 1 inhibitor that reduces serum urate levels by promoting urinary excretion of uric acid. It is co-administered with a xanthine oxidase inhibitor. METHODS: The TQT study (NCT04256629) was a randomized, placebo-controlled, double-blind, three-period, crossover study, conducted in healthy volunteers. A total of 24 participants received single doses of verinurad 24 mg extended release, 40 mg immediate release formulation (both co-administered with allopurinol 300 mg), and matching placebos. The primary endpoint was baseline- and placebo-adjusted Fridericia-corrected QTcF interval (ΔΔQTcF) at the concentration of interest. A prespecified linear mixed-effects concentration-QTc model was used to estimate the primary endpoint. Time-matched 12-lead digital electrocardiograms and plasma concentrations were measured at baseline and up to 48 h after dose in each participant. RESULTS: Estimated ΔΔQTcF at the highest clinically relevant scenario (76 ng/mL) was -2.7 msec (90% confidence interval [CI]: -4.6, -0.8). Furthermore, the upper 90% ΔΔQTcF CI was estimated to be below 10 msec at all observed verinurad concentrations. Supratherapeutic verinurad dose was used to achieve exposures eightfold higher than the highest clinically relevant exposure, thus waiving the need for positive control. CONCLUSIONS: As the effect on ΔΔQTcF was below the threshold for regulatory concern (10 msec) at the supratherapeutic exposure, it can be concluded that verinurad and allopurinol treatment does not induce QTcF prolongation at the highest clinically relevant exposures.

Effect of AZD9977 and spironolactone on serum potassium in heart failure with preserved or mildly reduced ejection fraction, and renal impairment: A randomized trial.

This phase Ib study compared the effects of AZD9977, a selective mineralocorticoid receptor modulator with predicted low hyperkalemia risk, with spironolactone on serum potassium (sK+ ) in patients with heart failure (HF) with preserved or mildly reduced ejection fraction (EF; ≥40%), and renal impairment. Patients with HF with EF greater than or equal to 40% and estimated glomerular filtration rate of 40-70 ml/min/1.73 m2 were randomized to once-daily AZD9977 100 mg or spironolactone 25 mg for 14 days, up-titrated to AZD9977 200 mg or spironolactone 50 mg for another 14 days. The primary end point was relative change (%) in sK+ for AZD9977 versus spironolactone (baseline to day 28). Serum/urinary electrolytes, fractional excretion (FE) of Na+ /K+ , plasma aldosterone, cortisol, and renin, and safety were also assessed. Sixty-eight patients were randomized (AZD9977, n = 33; spironolactone, n = 35). Mean (SD) age was 73.0 (8.5) years, 51.5% men. Mean sK+ change from baseline to day 28 was 5.7% (AZD9977) and 4.2% (spironolactone), and 1.5% and 4.2% at day 14. Relative change (95% confidence interval) in sK+ with AZD9977 versus spironolactone was -0.3% (-5.3% to 4.4%; day 28), and 3.4% (-0.8% to 7.5%; day 14). Median increase from baseline in plasma aldosterone at day 28 was 89.8 pmol/L for AZD9977 and 67.4 pmol/L for spironolactone. Median FE of K+ was 12.9% (AZD9977) and 10.1% (spironolactone). AZD9977 was well-tolerated. No discontinuations due to hyperkalemia occurred with either treatment. Evidence of target engagement for AZD9977 with a favorable safety profile, supports further evaluation of AZD9977 in patients with HF and renal impairment.

Pharmacokinetics, pharmacodynamics, and safety of verinurad with and without allopurinol in healthy Asian, Chinese, and non-Asian participants.

Verinurad is a selective inhibitor of uric acid transporter 1 (URAT1). Here, we assessed the safety, pharmacokinetics, and pharmacodynamics of verinurad + allopurinol and verinurad monotherapy in healthy participants. Studies 1 (NCT03836599) and 2 (NCT02608710) were randomized Phase 1 studies. In Study 1, 12 healthy Asian participants received 24 mg verinurad + 300 mg allopurinol or placebo, and 9 healthy Chinese participants received 12 mg verinurad + 300 mg allopurinol. In Study 2, 24 healthy non-Asian male participants received 12 mg verinurad. Safety analyses included assessment of adverse events (AEs). Pharmacokinetic parameters included maximum concentration (Cmax ) and area under plasma concentration-time curve (AUC) over 24 h (AUCτ ). Pharmacodynamic parameters included percentage change from baseline (day -1) in serum uric acid (sUA) and urinary uric acid (uUA). There were no serious AEs or deaths in either study. In Study 1, steady-state geometric mean (gCV%) Cmax and AUCτ values of verinurad after 7 days' dosing were 73.6 (29.0) ng/mL and 478 (18.4) ng·h/mL, respectively, in healthy Asian participants, and 42.0 (40.1) ng/mL and 264 (36.1) ng·h/mL, respectively, in healthy Chinese participants; in Study 2, gCV% values were 36.3 (36.5) ng/mL and 271 (31.0) ng·h/mL, respectively. sUA decreased and uUA excretion increased compared with baseline following verinurad + allopurinol (Study 1) or verinurad (Study 2). When accounting for dose, the steady-state pharmacokinetics of verinurad following multiple dosing were comparable between healthy Asian and Chinese participants and healthy non-Asian participants. Verinurad treatments were well tolerated, including at higher verinurad exposures than previously evaluated after repeated dosing.

From Policy to Practice: Measures Against Sexual Abuse by Swedish Sports Federations.

The sport movement must protect children and young athletes from all forms of abuse. However, research points to a disconnect between policy and implementation of policy against sexual abuse. No studies have investigated measures against sexual abuse in Swedish sport. The purpose of this study was to explore measures against sexual abuse in the 10 largest sports federations (SFs) for child and youth sport in Sweden. The study draws on interviews with representatives (n = 18) of the SFs and on a review of SFs' website content regarding sexual abuse and safe sport. Results show that the SFs have taken few or no measures against sexual abuse. Measures for safe sports vary in existence, development, and organization between the SFs, and many SFs are in the early stages of safe sport measures and practice. Although the SF representatives emphasize that sexual abuse is unacceptable, a conflict between making it visible or invisible emerges and creates a gap between policy and practice. Reproducing a culture of silence around sexual abuse in sports seems advantageously for SFs. Social and organizational factors that can debilitate safe sport measures and facilitate sexual abuse in sport are discussed.

In Vitro Assessment of the Drug-Drug Interaction Potential of Verinurad and Its Metabolites as Substrates and Inhibitors of Metabolizing Enzymes and Drug Transporters.

Verinurad is a selective uric acid transporter 1 (URAT1) inhibitor in development for the treatment of chronic kidney disease and heart failure. In humans, two major acyl glucuronide metabolites have been identified: direct glucuronide M1 and N-oxide glucuronide M8. Using in vitro systems recommended by regulatory agencies, we evaluated the interactions of verinurad, M1, and M8 with major drug-metabolizing enzymes and transporters and the potential for clinically relevant drug-drug interactions (DDIs). The IC50 for inhibition of CYP2C8, CYP2C9, and CYP3A4/5 for verinurad was ≥14.5 µM, and maximum free plasma concentration (Iu,max)/IC50 was <0.02 at the anticipated therapeutic Cmax and therefore not considered a DDI risk. Verinurad was not an inducer of CYP1A2, CYP2B6, or CYP3A4/5. Verinurad was identified as a substrate of the hepatic uptake transporter organic anion-transporting polypeptide (OATP) 1B3. Since verinurad hepatic uptake involved both active and passive transport, there is a low risk of clinically relevant DDIs with OATP, and further study is warranted. Verinurad was a substrate of the efflux transporters P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), and renal transporter organic anion transporter 1 (OAT1), although it is not considered a DDI risk in vivo because of dose-proportional pharmacokinetics (P-gp and BCRP) and limited renal excretion of verinurad (OAT1). M1 and M8 were substrates of multidrug resistance-associated protein (MRP) 2 and MRP4 and inhibitors of MRP2. Apart from verinurad being a substrate of OATP1B3 in vitro, the potential for clinically relevant DDIs involving verinurad and its metabolites as victims or perpetrators of metabolizing enzymes or drug transporters is considered low. SIGNIFICANCE STATEMENT: Drug transporters and metabolizing enzymes have an important role in the absorption and disposition of a drug and its metabolites. Using in vitro systems recommended by regulatory agencies, we determined that, apart from verinurad being a substrate of organic anion-transporting polypeptide 1B3, the potential for clinically relevant drug-drug interactions involving verinurad and its metabolites M1 and M8 as victims or perpetrators of metabolizing enzymes or drug transporters is considered low.

A semi-mechanistic exposure-response model to assess the effects of verinurad, a potent URAT1 inhibitor, on serum and urine uric acid in patients with hyperuricemia-associated diseases.

Verinurad, a uric acid transporter 1 (URAT1) inhibitor, lowers serum uric acid by promoting its urinary excretion. Co-administration with a xanthine oxidase inhibitor (XOI) to simultaneously reduce uric acid production rate reduces the potential for renal tubular precipitation of uric acid, which can lead to acute kidney injury. The combination is currently in development for chronic kidney disease and heart failure. The aim of this work was to apply and extend a previously developed semi-mechanistic exposure-response model for uric acid kinetics to include between-subject variability to verinurad and its combinations with XOIs, and to provide predictions to support future treatment strategies. The model was developed using data from 12 clinical studies from a total of 434 individuals, including healthy volunteers, patients with hyperuricemia, and renally impaired subjects. The model described the data well, taking into account the impact of various patient characteristics such as renal function, baseline fractional excretion of uric acid, and race. The potencies (EC50s) of verinurad (reducing uric acid reuptake), febuxostat (reducing uric acid production), and oxypurinol (reducing uric acid production) were: 29, 128, and 13,030 ng/mL, respectively. For verinurad, symptomatic hyperuricemic (gout) subjects showed a higher EC50 compared with healthy volunteers (37 ng/mL versus 29 ng/mL); while no significant difference was found for asymptomatic hyperuricemic patients. Simulations based on the uric acid model were performed to assess dose-response of verinurad in combination with XOI, and to investigate the impact of covariates. The simulations demonstrated application of the model to support dose selection for verinurad.

Dapagliflozin Added to Verinurad Plus Febuxostat Further Reduces Serum Uric Acid in Hyperuricemia: The QUARTZ Study.

CONTEXT: Combining a sodium-glucose cotransporter 2 inhibitor with a xanthine oxidase inhibitor (XOI) and a urate transporter 1 (URAT1) inhibitor may enhance serum uric acid (sUA) lowering. However, concerns exist regarding high urinary UA (uUA) excretion rates and subsequent crystallization in renal tubules. OBJECTIVE: To assess whether dapagliflozin added to verinurad, a selective URAT1 inhibitor, and febuxostat, an XOI, increases uUA excretion. DESIGN: Randomized, placebo-controlled, 2-way crossover study (NCT03316131). PATIENTS: Adults with asymptomatic hyperuricemia. INTERVENTIONS: Subjects (N = 36) were randomized to oral once-daily 9 mg verinurad plus 80 mg febuxostat plus 10 mg dapagliflozin for 7 days and 7 days of oral once-daily 9 mg verinurad plus 80 mg febuxostat plus placebo with an intervening 7- to 21-day washout period. MAIN OUTCOME MEASURE: Difference in peak uUA excretion between groups from baseline to day 7. Secondary outcomes included changes in sUA levels and 24-h uUA excretion. RESULTS: Both regimens lowered mean peak uUA excretion (least squares mean changes from baseline: -12.9 mg/h [95% confidence interval (CI): -21.0 to -4.7], dapagliflozin; -13.2 mg/h [95% CI -21.3 to -5.0], placebo). sUA concentrations were lower with dapagliflozin (mean treatment difference -62.3 µmol/L [95% CI -82.8 to -41.8]). Dapagliflozin did not impact verinurad pharmacokinetics, its main metabolites, or febuxostat or fasting plasma glucose levels vs verinurad plus febuxostat. There were no clinically relevant changes in safety parameters. CONCLUSIONS: Dapagliflozin further reduced sUA without influencing uUA excretion, suggesting that its combination with verinurad and febuxostat at the doses tested does not adversely affect kidney function. CLINICAL TRIAL REGISTRATION NUMBER: NCT03316131.

Higher Febuxostat Exposure Observed in Asian Compared with Caucasian Subjects Independent of Bodyweight.

BACKGROUND AND OBJECTIVE: Febuxostat is a xanthine oxidase inhibitor indicated for gout and hyperuricemia. This work investigates potential clinically relevant covariates for febuxostat pharmacokinetics with a special focus on Asian race and bodyweight. METHODS: Febuxostat plasma concentrations from 141 male subjects were obtained from two phase II studies in patients with hyperuricemia/gout (NCT02246673, NCT02317861) and one study in healthy volunteers (NCT01883167). Subjects were administered febuxostat oral doses from 10 to 80 mg. The pharmacokinetics of febuxostat was analyzed using non-linear mixed-effects modeling as implemented in NONMEM 7.3.0. The dataset consisted of racially diverse subjects, 40% being Japanese, 10% of unknown Asian origin, 39% Caucasian, and 10% Black. Most subjects (n = 92, 63%) had normal creatinine clearance (90 mL/min), while 52 subjects (36%) had mild renal impairment (creatinine clearance > 60 to < 90) at baseline. The effect of disease state, body weight, and creatinine clearance on febuxostat pharmacokinetics was investigated using stepwise covariate modeling. RESULTS: Febuxostat pharmacokinetics was well described by a two-compartment disposition model. Asian race was the only covariate resulting in a potentially clinically important increase in febuxostat area under the curve (1.64-fold, 90% confidence interval 1.48-1.79) compared with Caucasian individuals. The difference in body weight between Asian and Caucasian subjects did not explain the difference in febuxostat exposure. Absorption was modeled as a sequential zero- to first-order process with lag-time. CONCLUSIONS: In this pooled analysis of three studies, we show that Asian individuals have a 1.64-fold higher febuxostat exposure than Caucasians, independent of bodyweight or other investigated covariates. These findings may be of importance when selecting starting febuxostat doses in Asian patients.

In vitro human skin decontamination efficacy of MOF-808 in decontamination lotion following exposure to the nerve agent VX.

Metal-organic frameworks (MOFs) have shown promising properties for removal of chemical warfare agents, in particular for material decontamination and functionalized fabrics. The MOF-properties could also be beneficial for skin decontamination, especially when exposed to highly toxic and low volatile nerve agents. In such exposures, efficient decontamination is crucial for adequate medical management. In the present study, seven zirconium-based MOFs were evaluated for their ability to degrade VX and subsequently tested in vitro for decontamination of VX on human dermatomed skin. Of the MOFs evaluated, MOF-808 showed the greatest ability to degrade VX in an alkaline buffer with complete degradation of VX within 5 min. PCN-777, Zr-NDC and NU-1000 displayed degradation half-lives of approximately 10 min. When including MOF-808 in a skin friendly carrier with slightly acidic pH, a decreased agent degradation rate was observed, requiring over 24 h to reach complete degradation. In skin decontamination experiments, MOF-808 enhanced the efficacy compared to the carrier alone, essentially by improved agent absorption. Adding MOF-808 to Reactive Skin Decontamination Lotion (RSDL) did not improve the high effectiveness of RSDL alone. The present study showed that including MOF in skin decontamination lotions could be beneficial. Further studies should include optimizing the particulates and formulations.

Effect of Intensive Urate Lowering With Combined Verinurad and Febuxostat on Albuminuria in Patients With Type 2 Diabetes: A Randomized Trial.

RATIONALE & OBJECTIVE: Hyperuricemia has been implicated in the development and progression of chronic kidney disease. Verinurad is a novel, potent, specific urate reabsorption inhibitor. We evaluated the effects on albuminuria of intensive urate-lowering therapy with verinurad combined with the xanthine oxidase inhibitor febuxostat in patients with hyperuricemia and type 2 diabetes mellitus (T2DM). STUDY DESIGN: Phase 2, multicenter, prospective, randomized, double-blind, parallel-group, placebo-controlled trial. SETTING & PARTICIPANTS: Patients 18 years or older with hyperuricemia, albuminuria, and T2DM. INTERVENTION: Patients randomly assigned 1:1 to verinurad (9mg) plus febuxostat (80mg) or matched placebo once daily for 24 weeks. OUTCOMES: The primary end point was change in urinary albumin-creatinine ratio (UACR) from baseline after 12 weeks' treatment. Secondary end points included safety and tolerability and effect on glomerular filtration. RESULTS: 60 patients were enrolled (n=32, verinurad and febuxostat; n=28, placebo). UACRs after treatment with verinurad plus febuxostat were lower than after placebo at 1, 12, and 24 weeks: -38.6% (90% CI, -60.9% to-3.6%), -39.4% (90% CI, -61.8% to-3.8%), and-49.3% (90% CI, -68.2% to-19.0%), respectively. Serum urate levels after treatment with verinurad plus febuxostat were 59.6% and 63.7% lower than after placebo at 12 and 24 weeks, respectively. No clinically meaningful changes were observed in estimated glomerular filtration rate or serum creatinine or serum cystatin C concentrations. Verinurad plus febuxostat was well tolerated. LIMITATIONS: Sample size and study duration were insufficient to evaluate definitive effects of verinurad plus febuxostat on UACR and glomerular filtration. Generalizability was limited by exclusion of patients with stages 4 and 5 chronic kidney disease. CONCLUSIONS: Verinurad plus febuxostat reduced albuminuria and lowered serum urate concentrations in patients with T2DM, albuminuria, and hyperuricemia. Definitive assessment of their combined impact on preservation of kidney function awaits larger clinical studies. FUNDING: This study was supported by AstraZeneca. TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT03118739.

Differentiating the Sodium-Glucose Cotransporter 1 Inhibition Capacity of Canagliflozin vs. Dapagliflozin and Empagliflozin Using Quantitative Systems Pharmacology Modeling.

The aim of this research was to differentiate dapagliflozin, empagliflozin, and canagliflozin based on their capacity to inhibit sodium-glucose cotransporter (SGLT) 1 and 2 in patients with type 2 diabetes using a previously developed quantitative systems pharmacology model of renal glucose filtration, reabsorption, and excretion. The analysis was based on pooled, mean study-level data on 24-hour urinary glucose excretion, average daily plasma glucose, and estimated glomerular filtration rate collected from phase I and II clinical trials of SGLT2 inhibitors. Variations in filtered glucose across clinical studies were shown to drive the apparent differences in the glucosuria dose-response relationships among the gliflozins. A normalized dose-response analysis demonstrated similarity of dapagliflozin and empagliflozin, but not canagliflozin. At approved doses, SGLT1 inhibition by canagliflozin but not dapagliflozin or empagliflozin contributed to ~ 10% of daily urinary glucose excretion.

Evaluation of the ResistancePlus MG FleXible Assay for Detection of Wild-Type and 23S rRNA-Mutated Mycoplasma genitalium Strains.

Antibiotic resistance in Mycoplasma genitalium is rising globally, and resistance-guided diagnostics can facilitate targeted and timely treatment. The ResistancePlus MG FleXible (RPMG Flex) assay for the detection of M. genitalium and macrolide resistance-mediating mutations (MRMM) was evaluated for analytical sensitivity, specificity, reproducibility, and inhibition in the presence of interfering substances by simulating M. genitalium-negative pooled urine and swab matrices with M. genitalium cultures. Furthermore, the clinical sensitivity of the assay was evaluated and compared with a reference real-time PCR assay. The analytical sensitivity of the RPMG Flex assay was 157 genomes/ml for wild-type (WT) and 387 genomes/ml for MRMM strains in both matrices. For clinical specimens, the RPMG assay had an overall sensitivity of 96.1% (95% urine: 10/10 WT, 9/10 MRMM; 96.5% swab: 25/26 WT, 26/29 MRMM) compared to 85.7% for the MgPa/MagNAPure24 assay (95% urine: 19/20; 87% swab: 48/57). Clinical specificity was 100% for urine and 98.5% for swab specimens, respectively. No inhibition due to the presence of any of the tested interfering substances was observed. The RPMG Flex assay was more sensitive than the reference MgPa assay, in particular, for swab specimens. The implementation of this assay may increase ease of use and considerably decrease hands-on time for sample preparation compared to a standard block-based assay. The RPMG Flex assay for the GeneXpert Dx system provides a much-needed platform for the simultaneous detection of MG and MRMM and may thereby facilitate resistance-guided therapy for M. genitalium infections.

Development and Validation of the Ambulance Nurse Competence Scale.

INTRODUCTION: In recent decades, major competency shifts have taken place in prehospital care in Sweden because staffing ambulances with registered/specialized nurses has become a priority. The aim of this study was to develop and validate a new instrument to measure the self-reported professional competency of specialist ambulance nursing students and registered/specialist nurses working in prehospital care. METHODS: This study used a quantitative cross-sectional design to evaluate psychometric properties of a new instrument. The sample included 179 registered/specialist ambulance nurses and 34 specialist ambulance nursing students. RESULTS: The analyses resulted in the Ambulance Nurse Competence (ANC) scale, consisting of 43 items and covering 8 factors: Nursing Care (n = 8), Value-based Nursing Care (n = 5), Medical Technical Care (n = 5), Care Environment's Community (n = 4), Care Environment's Serious Events (n = 8), Leadership Management (n = 3), Supervision and Professional Conduct (n = 4), and Research and Development (n = 6). All factors except Leadership Management achieved a Cronbach's alpha value greater than 0.71, explaining 59.62% of the total variance. DISCUSSION: The ANC scale was systematically tested and showed satisfactory psychometrical properties. The ANC scale can be used in the education programs of future registered/specialist ambulance nurses as a tool for self-reflected learning and could also be of potential use in identifying competence gaps in registered/specialist ambulance nurses, which could direct the design of introductory programs. The scale could also be used as an outcome measure together with other instruments.

Comparison of the urinary glucose excretion contributions of SGLT2 and SGLT1: A quantitative systems pharmacology analysis in healthy individuals and patients with type 2 diabetes treated with SGLT2 inhibitors.

AIM: To develop a quantitative drug-disease systems model to investigate the paradox that sodium-glucose co-transporter (SGLT)2 is responsible for >80% of proximal tubule glucose reabsorption, yet SGLT2 inhibitor treatment results in only 30% to 50% less reabsorption in patients with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: A physiologically based four-compartment model of renal glucose filtration, reabsorption and excretion via SGLT1 and SGLT2 was developed as a system of ordinary differential equations using R/IQRtools. SGLT2 inhibitor pharmacokinetics and pharmacodynamics were estimated from published concentration-time profiles in plasma and urine and from urinary glucose excretion (UGE) in healthy people and people with T2DM. RESULTS: The final model showed that higher renal glucose reabsorption in people with T2DM versus healthy people was associated with 54% and 28% greater transporter capacity for SGLT1 and SGLT2, respectively. Additionally, the analysis showed that UGE is highly dependent on mean plasma glucose and estimated glomerular filtration rate (eGFR) and that their consideration is critical for interpreting clinical UGE findings. CONCLUSIONS: Quantitative drug-disease system modelling revealed mechanistic differences in renal glucose reabsorption and UGE between healthy people and those with T2DM, and clearly showed that SGLT2 inhibition significantly increased glucose available to SGLT1 downstream in the tubule. Importantly, we found that the findings of lower than expected UGE with SGLT2 inhibition are explained by the shift to SGLT1, which recovered additional glucose (~30% of total).

Tenapanor administration and the activity of the H+ -coupled transporter PepT1 in healthy volunteers.

AIM: Tenapanor (RDX5791/AZD1722), an inhibitor of gastrointestinal Na+ /H+ exchanger NHE3, is being evaluated for the treatment of patients with constipation-predominant irritable bowel syndrome and the treatment of hyperphosphataemia in patients with chronic kidney disease on dialysis. By reducing intestinal H+ secretion, inhibition of NHE3 by tenapanor could indirectly affect H+ -coupled transporter activity, leading to drug-drug interactions. We investigated the effect of tenapanor on the activity of the H+ -coupled peptide transporter PepT1 via assessment of the pharmacokinetics of cefadroxil - a compound transported by PepT1 - in healthy volunteers. METHODS: In this open-label, two-period crossover, phase 1 study (NCT02140281), 28 volunteers received in random order: a single dose of cefadroxil 500 mg for 1 day; and tenapanor 15 mg twice daily over 4 days followed by single doses of both cefadroxil 500 mg and tenapanor 15 mg on day 5. There was a 4-day washout between treatment periods. RESULTS: Cefadroxil exposure was similar when administered alone or in combination with tenapanor {geometric least-squares mean ratios [(cefadroxil + tenapanor)/cefadroxil] (90% confidence interval): area under the concentration-time curve 93.3 (90.6-96.0)%; maximum concentration in plasma 95.9 (89.8-103)%}. Tenapanor treatment caused a softening of stool consistency and an increase in stool frequency, consistent with its expected pharmacodynamic effect. No safety concerns were identified and tenapanor was not detected in plasma. CONCLUSIONS: These results suggest that tenapanor 15 mg twice daily does not have a clinically relevant impact on the activity of the H+ -coupled transporter PepT1 in humans. This may guide future research on drug-drug interactions involving NHE3 inhibitors.

Effect of Food Intake on the Pharmacodynamics of Tenapanor: A Phase 1 Study.

Tenapanor (RDX5791/AZD1722) is a minimally systemic small-molecule inhibitor of the sodium/hydrogen exchanger NHE3. Tenapanor acts in the gut to reduce absorption of sodium and phosphate. This phase 1 open-label, 3-way crossover study (NCT02226783) evaluated the effect of food on the pharmacodynamics of tenapanor. Eighteen volunteers completed a randomized sequence of three 4-day treatments with tenapanor hydrochloride 15 mg twice daily: before food, after food, and while fasting. Participants received a diet standardized for sodium content. Stool sodium was significantly higher with tenapanor administration before versus after food (difference, +8.8 mmol/day, P = .006) or while fasting (+11.8 mmol/day, P = .0004). Differences in urinary sodium were not significant. Stool phosphorus was not significantly different with tenapanor before versus after food and significantly higher before food versus while fasting (+4.9 mmol/day, P = .006). Urinary phosphorus was significantly lower when tenapanor was administered before (-3.9 mmol/day, P = .0005) or after food (-3.7 mmol/day, P = .0009) versus while fasting. No serious adverse events were reported. These data suggest the effect of tenapanor on sodium absorption is most pronounced when administered before meals, whereas the effect on phosphate is similar whether administered before or after meals. This may support different timings of tenapanor administration with respect to food for sodium- and phosphate-related indications.