The putative proton-coupled organic cation antiporter is involved in uptake of triptans into human brain capillary endothelial cells.

BACKGROUND: Triptans are anti-migraine drugs with a potential central site of action. However, it is not known to what extent triptans cross the blood-brain barrier (BBB). The aim of this study was therefore to determine if triptans pass the brain capillary endothelium and investigate the possible underlying mechanisms with focus on the involvement of the putative proton-coupled organic cation (H+/OC) antiporter. Additionally, we evaluated whether triptans interacted with the efflux transporter, P-glycoprotein (P-gp). METHODS: We investigated the cellular uptake characteristics of the prototypical H+/OC antiporter substrates, pyrilamine and oxycodone, and seven different triptans in the human brain microvascular endothelial cell line, hCMEC/D3. Triptan interactions with P-gp were studied using the IPEC-J2 MDR1 cell line. Lastly, in vivo neuropharmacokinetic assessment of the unbound brain-to-plasma disposition of eletriptan was conducted in wild type and mdr1a/1b knockout mice. RESULTS: We demonstrated that most triptans were able to inhibit uptake of the H+/OC antiporter substrate, pyrilamine, with eletriptan emerging as the strongest inhibitor. Eletriptan, almotriptan, and sumatriptan exhibited a pH-dependent uptake into hCMEC/D3 cells. Eletriptan demonstrated saturable uptake kinetics with an apparent Km of 89 ± 38 µM and a Jmax of 2.2 ± 0.7 nmol·min-1·mg protein-1 (n = 3). Bidirectional transport experiments across IPEC-J2 MDR1 monolayers showed that eletriptan is transported by P-gp, thus indicating that eletriptan is both a substrate of the H+/OC antiporter and P-gp. This was further confirmed in vivo, where the unbound brain-to-unbound plasma concentration ratio (Kp,uu) was 0.04 in wild type mice while the ratio rose to 1.32 in mdr1a/1b knockout mice. CONCLUSIONS: We have demonstrated that the triptan family of compounds possesses affinity for the H+/OC antiporter proposing that the putative H+/OC antiporter plays a role in the BBB transport of triptans, particularly eletriptan. Our in vivo studies indicate that eletriptan is subjected to simultaneous brain uptake and efflux, possibly facilitated by the putative H+/OC antiporter and P-gp, respectively. Our findings offer novel insights into the potential central site of action involved in migraine treatment with triptans and highlight the significance of potential transporter related drug-drug interactions.

Outcomes of Kidneys Transplanted From Hepatitis C Viremic Donors to Naive Recipients From an Appalachian Rural Kidney Transplant Program.

OBJECTIVES: Before the advent of direct-acting antiviral therapy for hepatitis C virus, a large proportion of kidneys from donors with hepatitis C viremia were discarded. Hepatitis C virus is now amenable to effective treatment with excellent seronegativity rates. In this study, we review the outcomes of hepatitis C viremic kidneys transplanted into hepatitis C-naive recipients. MATERIALS AND METHODS: In this retrospective observational study, we examined 6 deceased donor kidneys with hepatitis C viremia that were transplanted into hepatitis C-naive recipients between March 2020 and April 2021 at a single center. Because of health insurance constraints, patients were treated for hepatitis C virus with glecaprevir/pibrentasvir for 8 weeks following seroconversion posttransplant. Primary outcome measured was viral seroconversion; secondary outcomes included graft function, posttransplant complications, and all-cause mortality. RESULTS: On average, patients seroconverted 6 days (range, 4-10 d) after transplant and began treatment 26 days (range, 15-37 d) after seroconversion. An 8-week course of antiviral treatment was successful in preventing acute hepatitis C virus infection in all patients. Posttransplant median creatinine was 1.96 mg/dL (range, 1-4.55 mg/dL), whereas median estimated glomerular filtration rate was 41.33 mL/min/1.73 m2 (range, 17-85 mL/min/1.73 m2). Patient survival rate was 66.7%, and death-censored graft survival rate was 100%. Two patients died from unrelated reasons: 1 from acute respiratory failure secondary to SARS-CoV-2 infection and 1 from posttransplant lymphoproliferative disorder. Two patients developed allograft rejection posttransplant (1 developed antibody mediated rejection, 1 developed borderline T-cell-mediated cellular rejection). Other major complications included neutropenia, fungal rash, SARS-CoV-2 infection, cytomegalovirus, BK virus, and Epstein-Barr virus reactivation. CONCLUSIONS: Use of hepatitis C-viremic donor kidneys for transplant is a safe option and has great potential to increase the kidney donor pool, as long as high index of suspicion is maintained for allograft rejection and opportunistic infections.

Sequencing considerations in the third-line treatment of metastatic colorectal cancer.

Numerous advances in the standard of care for metastatic colorectal cancer (mCRC), including the approval of several new treatments indicated for treatment in the third line or later (3L+), have been made, yet data and appropriate guidance on the optimal sequencing and treatment strategies for these lines of therapy are lacking. Four treatments-regorafenib, trifluridine/tipiracil alone or with bevacizumab, and fruquintinib-are FDA-approved and recommended by the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for the treatment of mCRC in the 3L+. When considering sequencing of treatment options for patients in the 3L+, the goal of treatment is to improve survival, but also maintain quality of life, a goal that requires consideration of relative efficacy and cumulative toxicity such as persistent myelosuppression.

Recovery of chronic motor neuropathy due to acute intermittent porphyria after givosiran treatment in a young boy: a case report.

BACKGROUND: We describe the first case of a pediatric patient with acute intermittent porphyria and severe chronic porphyric neuropathy treated with givosiran, a small-interfering RNA that drastically decreases delta-aminolevulinic acid production and reduces porphyric attacks' recurrence. CASE REPORT: A 12-year-old male patient with refractory acute intermittent porphyria and severe porphyric neuropathy was followed prospectively for 12 months after givosiran initiation (subcutaneous, 2.5 mg/kg monthly). Serial neurological, structural, and resting-state functional magnetic resonance imaging (MRI) evaluations were performed, including clinical scales and neurophysiological tests. Delta-aminolevulinic acid urinary levels dropped drastically during treatment. In parallel, all the administered neurological rating scales and neurophysiological assessments showed improvement in all domains. Moreover, an improvement in central motor conduction parameters and resting-state functional connectivity in the sensory-motor network was noticed. At the end of the follow-up, the patient could walk unaided after using a wheelchair for 5 years. CONCLUSIONS: A clear beneficial effect of givosiran was demonstrated in our patient with both clinical and peripheral nerve neurophysiologic outcome measures. Moreover, we first reported a potential role of givosiran in recovering central motor network impairment in acute intermittent porphyria (AIP), which was previously unknown. This study provides Class IV evidence that givosiran improves chronic porphyric neuropathy.

Exploring a Lux® i-Amylose-3 column in normal phase and polar-organic mode for chiral separation of cathinone derivatives and pyrovalerones using high-performance liquid chromatography.

Each year, new psychoactive substances appear on the global drug market leading to constant changes. Most of these compounds with stimulating effect possess a chiral center, thus leading to two enantiomers with presumably different pharmacological properties. Among them, synthetic cathinones, often misleadingly traded as "bath salts," play an important role. There is little knowledge about the distinct effect of the enantiomers. The aim of this study was to test a commercially available Lux® i-Amylose-3 column by HPLC-UV for enantiorecognition of cathinone derivatives. Overall, 80 compounds were tested in normal phase mode, where 75 substances were separated under initial conditions. After method optimization, at least partial separation was achieved for the remaining compounds. The same set of substances was measured in polar-organic mode, where 63 analytes were resolved into their enantiomers under initial conditions with very short retention times. Both modes showed complementary results for the individual compounds. Furthermore, the tested methods proved to be suitable for differentiation of positional isomers, which can be useful for drug checking programs. All measurements were carried out under isocratic conditions, and intraday and interday repeatability tests were performed.

Efficacy of Regorafenib and Trifluridine/Tipiracil According to Extended RAS Evaluation in Advanced Metastatic Colorectal Cancer Patients: A Multicenter Retrospective Analysis.

BACKGROUND: There are few molecular markers driving treatment selection in later lines of treatment for advanced colorectal cancer patients. The vast majority of patients who progress after first- and second-line therapy undergo chemotherapy regardless of molecular data. OBJECTIVE: We aimed to assess the prognostic and predictive effects of specific RAS mutations on overall survival of patients receiving regorafenib (rego), trifluridine/tipiracil (TFD/TPI), or both. PATIENTS AND METHODS: This was a retrospective observational study based on data from a previous study of our research network, involving nine Italian institutions over a 10-year timeframe (2012-2022). Extended RAS analysis, involving KRAS exon 2-4 and NRAS exon 2-4, and BRAF were the main criteria for inclusion in this retrospective evaluation. Patients with BRAF mutation were excluded. Patients were classified according to treatment (rego- or TFD/TPI-treated) and RAS mutational status (wild-type [WT], KRAS codon 12 mutations, KRAS codon 13 mutations, KRAS rare mutations and NRAS mutations, KRAS G12C mutation and KRAS G12D mutation). RESULTS: Overall, 582 patients were included in the present analysis. Overall survival did not significantly differ in rego-treated patients according to RAS extended analysis, although a trend toward a better median survival in patients carrying G12D mutation (12.0 months), Codon 13 mutation (8.0 months), and Codon 12 mutation (7.0 months) has been observed, when compared with WT patients (6.0 months). Overall survival did not significantly differ in TFD/TPI-treated patients according to RAS extended analysis, although a trend toward a better median survival in WT patients had been observed (9.0 months) in comparison with the entire population (7.0 months). Patients receiving both drugs displayed a longer survival when compared with the population of patients receiving rego alone (p = 0.005) as well as the population receiving TFD/TPI alone (p < 0.001), suggesting a group enriched for favorable prognostic factors. However, when each group was analyzed separately, the addition of TFD/TPI therapy to the rego-treated group improved survival only in all-RAS WT patients (p = 0.003). Differently, the addition of rego therapy to TFD/TPI-treated patients significantly improved OS in the Codon 12 group (p = 0.0004), G12D group (p = 0.003), and the rare mutations group (p = 0.02), in addition to all-RAS WT patients (p = 0.002). The rego-TFD/TPI sequence, compared with the reverse sequence, significantly improved OS only in the KRAS codon 12 group (p = 0.003). CONCLUSIONS: Our data demonstrate that RAS mutations do not affect outcome in rego-treated patients as well as TFD/TPI-treated patients. Nevertheless, a trend toward a higher efficacy of rego in RAS-mutated (in particular codon 12, rare RAS mutations, and G12D) patients has been recorded. The rego-TFD/TPI sequence seems to be superior to the reverse sequence in patients carrying an RAS codon 12 mutation, although the impact of other factors as disease burden or performance status cannot be excluded.

Design, Synthesis, and Pharmacological Evaluation of Spiro[carbazole-3,3'-pyrrolidine] Derivatives as cGAS Inhibitors for Treatment of Acute Lung Injury.

Overactivation of cyclic GMP-AMP synthase (cGAS) is implicated in the occurrence of many inflammatory and autoimmune diseases, and inhibition of cGAS with a specific inhibitor has been proposed as a potential therapeutic strategy. However, only a few low-potency cGAS inhibitors have been reported, and few are suitable for clinical investigation. As a continuation of our structural optimization on the reported cGAS inhibitor 6 (G140), we developed a series of spiro[carbazole-3,3'-pyrrolidine] derivatives bearing a unique 2-azaspiro[4.5]decane structural motif, among which compound 30d-S was identified with high cellular effects against cGAS. This compound showed improved plasma exposure, lower clearance, and an oral bioavailability of 35% in rats. Moreover, in the LPS-induced acute lung injury (ALI) mice model, oral administration of compound 30d-S at 30 mg/kg markedly reduced lung inflammation and alleviated histopathological changes. These results confirm that 30d-S is a new efficacious cGAS inhibitor and is worthy of further investigation.

Elexacaftor/tezacaftor/ivacaftor influences body composition in adults with cystic fibrosis: a fully automated CT-based analysis.

A poor nutritional status is associated with worse pulmonary function and survival in people with cystic fibrosis (pwCF). CF transmembrane conductance regulator modulators can improve pulmonary function and body weight, but more data is needed to evaluate its effects on body composition. In this retrospective study, a pre-trained deep-learning network was used to perform a fully automated body composition analysis on chest CTs from 66 adult pwCF before and after receiving elexacaftor/tezacaftor/ivacaftor (ETI) therapy. Muscle and adipose tissues were quantified and divided by bone volume to obtain body size-adjusted ratios. After receiving ETI therapy, marked increases were observed in all adipose tissue ratios among pwCF, including the total adipose tissue ratio (+ 46.21%, p < 0.001). In contrast, only small, but statistically significant increases of the muscle ratio were measured in the overall study population (+ 1.63%, p = 0.008). Study participants who were initially categorized as underweight experienced more pronounced effects on total adipose tissue ratio (p = 0.002), while gains in muscle ratio were equally distributed across BMI categories (p = 0.832). Our findings suggest that ETI therapy primarily affects adipose tissues, not muscle tissue, in adults with CF. These effects are primarily observed among pwCF who were initially underweight. Our findings may have implications for the future nutritional management of pwCF.

Predictive significance of FGFR4 p.G388R polymorphism in metastatic colorectal cancer patients receiving trifluridine/tipiracil (TAS-102) treatment.

BACKGROUND: TAS-102 (Lonsurf®) is an oral fluoropyrimidine consisting of a combination of trifluridine (a thymidine analog) and tipiracil (a thymidine phosphorylation inhibitor). The drug is effective in metastatic colorectal cancer (mCRC) patients refractory to fluorouracil, irinotecan and oxaliplatin. This study is a real-world analysis, investigating the interplay of genotype/phenotype in relation to TAS-102 sensitivity. METHODS: Forty-seven consecutive mCRC patients were treated with TAS-102 at the National Cancer Institute of Naples from March 2019 to March 2021, at a dosage of 35 mg/m2, twice a day, in cycles of 28 days (from day 1 to 5 and from day 8 to 12). Clinical-pathological parameters were described. Activity was evaluated with RECIST criteria (v1.1) and toxicity with NCI-CTC (v5.0). Survival was depicted through the Kaplan-Meyer curves. Genetic features of patients were evaluated with Next Generation Sequencing (NGS) through the Illumina NovaSeq 6000 platform and TruSigt™Oncology 500 kit. RESULTS: Median age of patients was 65 years (range: 46-77). Forty-one patients had 2 or more metastatic sites and 38 patients underwent to more than 2 previous lines of therapies. ECOG (Eastern Cooperative Oncology Group) Performance Status (PS) was 2 in 19 patients. The median number of TAS-102 cycles was 4 (range: 2-12). The most frequent toxic event was neutropenia (G3/G4 in 16 patients). There were no severe (> 3) non-haematological toxicities or treatment-related deaths. Twenty-six patients experienced progressive disease (PD), 21 stable disease (SD). Three patients with long-lasting disease control (DC: complete, partial responses or stable disease) shared an FGFR4 (p.Gly388Arg) mutation. Patients experiencing DC had more frequently a low tumour growth rate (P = 0.0306) and an FGFR4 p.G388R variant (P < 0.0001). The FGFR4 Arg388 genotype was associated with better survival (median: 6.4 months) compared to the Gly388 genotype (median: 4 months); the HR was 0.25 (95% CI 0.12- 0.51; P = 0.0001 at Log-Rank test). CONCLUSIONS: This phenotype/genotype investigation suggests that the FGFR4 p.G388R variant may serve as a new marker for identifying patients who are responsive to TAS-102. A mechanistic hypothesis is proposed to interpret these findings.

PREFUL MRI for Monitoring Perfusion and Ventilation Changes after Elexacaftor-Tezacaftor-Ivacaftor Therapy for Cystic Fibrosis: A Feasibility Study.

Purpose To assess the feasibility of monitoring the effects of elexacaftor-tezacaftor-ivacaftor (ETI) therapy on lung ventilation and perfusion in people with cystic fibrosis (CF), using phase-resolved functional lung (PREFUL) MRI. Materials and Methods This secondary analysis of a multicenter prospective study was carried out between August 2020 and March 2021 and included participants 12 years or older with CF who underwent PREFUL MRI, spirometry, sweat chloride test, and lung clearance index assessment before and 8-16 weeks after ETI therapy. For PREFUL-derived ventilation and perfusion parameter extraction, two-dimensional coronal dynamic gradient-echo MR images were evaluated with an automated quantitative pipeline. T1- and T2-weighted MR images and PREFUL perfusion maps were visually assessed for semiquantitative Eichinger scores. Wilcoxon signed rank test compared clinical parameters and PREFUL values before and after ETI therapy. Correlation of parameters was calculated as Spearman ρ correlation coefficient. Results Twenty-three participants (median age, 18 years [IQR: 14-24.5 years]; 13 female) were included. Quantitative PREFUL parameters, Eichinger score, and clinical parameters (lung clearance index = 21) showed significant improvement after ETI therapy. Ventilation defect percentage of regional ventilation decreased from 18% (IQR: 14%-25%) to 9% (IQR: 6%-17%) (P = .003) and perfusion defect percentage from 26% (IQR: 18%-36%) to 19% (IQR: 13%-24%) (P = .002). Areas of matching normal (healthy) ventilation and perfusion increased from 52% (IQR: 47%-68%) to 73% (IQR: 61%-83%). Visually assessed perfusion scores did not correlate with PREFUL perfusion (P = .11) nor with ventilation-perfusion match values (P = .38). Conclusion The study demonstrates the feasibility of PREFUL MRI for semiautomated quantitative assessment of perfusion and ventilation changes in response to ETI therapy in people with CF. Keywords: Pediatrics, MR-Functional Imaging, Pulmonary, Lung, Comparative Studies, Cystic Fibrosis, Elexacaftor-Tezacaftor-Ivacaftor Therapy, Fourier Decomposition, PREFUL, Free-Breathing Proton MRI, Pulmonary MRI, Perfusion, Functional MRI, CFTR, Modulator Therapy, Kaftrio Clinical trial registration no. NCT04732910 Supplemental material is available for this article. © RSNA, 2024.

Synchronous spectrofluorimetry and chemometric modeling: A synergistic approach for analyzing simeprevir and daclatasvir, with application to pharmacokinetics evaluation.

Simeprevir and daclatasvir represent a cornerstone in the management of Hepatitis C Virus infection, a global health concern that affects millions of people worldwide. In this study, we propose a synergistic approach combining synchronous spectrofluorimetry and chemometric modeling i.e. Partial Least Squares (PLS-1) for the analysis of simeprevir and daclatasvir in different matrices. Moreover, the study employs firefly algorithms to further optimize the chemometric models via selecting the most informative features thus improving the accuracy and robustness of the calibration models. The firefly algorithm was able to reduce the number of selected wavelengths to 47-44% for simeprevir and daclatasvir, respectively offering a fast and sensitive technique for the determination of simeprevir and daclatasvir. Validation results underscore the models' effectiveness, as evidenced by recovery rates close to 100% with relative root mean square error of prediction (RRMSEP) of 2.253 and 2.1381 for simeprevir and daclatasvir, respectively. Moreover, the proposed models have been applied to determine the pharmacokinetics of simeprevir and daclatasvir, providing valuable insights into their distribution and elimination patterns. Overall, the study demonstrates the effectiveness of synchronous spectrofluorimetry coupled with multivariate calibration optimized by firefly algorithms in accurately determining and quantifying simeprevir and daclatasvir in HCV antiviral treatment, offering potential applications in pharmaceutical formulation analysis and pharmacokinetic studies for these drugs.

The emerging emetogenicity of trifluridine/tipiracil (TAS­102) from patient self-reporting: a multicenter, prospective, observational study.

BACKGROUND: Trifluridine/tipiracil (TAS-102) is an oral anticancer drug with adequate efficacy in unresectable colorectal cancer, but frequently also induces chemotherapy-induced nausea and vomiting (CINV). To investigate the occurrence of CINV and antiemetic therapy in patients with colorectal cancer treated with TAS-102 (JASCC-CINV 2001). METHODS: We conducted a multicenter, prospective, observational study in patients with colorectal cancer who received TAS-102 without dose reduction for the first time. Primary endpoint was the incidence of vomiting during the overall period. Secondary endpoints were the incidence of nausea, significant nausea, anorexia, other adverse events (constipation, diarrhea, insomnia, fatigue, dysgeusia) and patient satisfaction. Patient diaries were used for primary and secondary endpoints. All adverse events were subjectively assessed using PRO-CTCAE ver 1.0. and CTCAE ver 5.0. RESULTS: Data from 100 of the 119 enrolled patients were analyzed. The incidence of vomiting, nausea, and significant nausea was 13%, 67%, and 36%, respectively. The incidence of vomiting in patients with and without prophylactic antiemetic therapy were 20.8% and 10.5%, respectively. Prophylactic antiemetics were given to 24% of patients, of whom 70% received D2 antagonists. Multivariate Cox proportional hazards analysis showed that experience of CINV in previous treatment tended to be associated with vomiting (hazard ratio [HR]: 7.13, 95% confidence interval [CI]: 0.87-58.5, P = 0.07), whereas prophylactic antiemetic administration was not (HR: 1.61, 95 CI: 0.50-5.21, P = 0.43). With regard to patient satisfaction, the proportion of patients who were "very satisfied," "satisfied," "slightly satisfied" or "somewhat satisfied" was 81.8%. CONCLUSIONS: The low incidence of vomiting and high patient satisfaction suggest that TAS-102 does not require the use of uniform prophylactic antiemetic treatments. However, patients with the experience of CINV in previous treatment might require prophylactic antiemetic treatment.

CSF1R inhibitor PLX3397 depletes microglia in Mongolian gerbil Meriones unguiculatus, but not in syrian hamster Mesocricetus auratus.

Microglia are the residential immune cells in the central nervous system. Their roles as innate immune cells and regulators of synaptic remodeling are critical to the development and the maintenance of the brain. Numerous studies have depleted microglia to elucidate their involvement in healthy and pathological conditions. PLX3397, a blocker of colony stimulating factor 1 receptor (CSF1R), is widely used to deplete mouse microglia due to its non-invasiveness and convenience. Recently, other small rodents, including Syrian hamsters (Mesocricetus auratus) and Mongolian gerbils (Meriones unguiculatus), have been recognized as valuable animal models for studying brain functions and diseases. However, whether microglia depletion via PLX3397 is feasible in these species remains unclear. Here, we administered PLX3397 orally via food pellets to hamsters and gerbils. PLX3397 successfully depleted gerbil microglia but had no effect on microglial density in hamsters. Comparative analysis of the CSF1R amino acid sequence in different species hints that amino acid substitutions in the juxtamembrane domain may potentially contribute to the inefficacy of PLX3397 in hamsters.

Pharmacokinetics, Pharmacodynamics, and Safety of Evocalcet (KHK7580), a Novel Calcimimetic Agent: An Open-Label, Single- and Multiple-Dose, Phase I Trial in Healthy Chinese Subjects.

Purpose: This study explored the pharmacokinetics (PK), pharmacodynamics (PD), and safety of evocalcet (KHK7580), a new calcimimetic agent, in healthy Chinese subjects following single and multiple doses. Methods: This was a single-center, open-label phase I trial conducted in China. The study started from the single-dose cohorts (1, 3, 6, 12 mg evocalcet, step-by-step administration) and proceeded to the multiple-dose cohort (6 mg evocalcet once daily for eight days). Blood and urine samples were collected at the designated time points for pharmacokinetic and pharmacodynamic analysis. Safety was evaluated by treatment-emergent adverse events (TEAEs), clinical laboratory tests, vital signs, electrocardiograms (ECGs), and ophthalmological examination. Results: Among 42 enrolled subjects, eight in each single-dose cohort and 10 in multiple-dose cohort, 40 subjects completed the study. In single-dose cohorts, tmax was 1.00-2.00 h and declined biphasically. The mean t1/2 was 15.99-20.84 h. Evocalcet exposure in AUC0-inf, AUC0-t, and Cmax showed a dose-proportional increase. In the multiple-dose cohort, tmax was 2.00 h and declined biphasically after multiple administrations. The accumulation was negligible. Ctrough levels were similar across days and steady from 24 hours after the first administration. The mean t1/2 was 15.59 h. PD analysis showed that evocalcet decreased intact parathyroid hormone and corrected calcium levels in a dose-dependent manner. Seventeen (40.5%) subjects reported TEAEs. No serious or severe TEAE occurred. Conclusion: In healthy Chinese subjects, evocalcet demonstrated dose-dependent PK and PD properties and was well-tolerated.

Structural and functional perspectives on interactions between synthetic cathinones and monoamine transporters.

Synthetic cathinone derivatives comprise a family of psychoactive compounds structurally related to amphetamine. Over the last decade, clandestine chemists have synthesized a consistent stream of innovative cathinone derivatives to outpace governmental regulatory restrictions. Many of these unregulated substances are produced and distributed as designer drugs. Two of the principal chemical scaffolds exploited to expand the synthetic cathinone family are methcathinone and α-pyrrolidinopentiophenone (or α-pyrrolidinovalerophenone, α-PVP). These compounds' main physiological targets are monoamine transporters, where they promote addiction by potentiating dopaminergic neurotransmission. This chapter describes techniques used to study the pharmacodynamic properties of cathinones at monoamine transporters in vitro. Biochemical techniques described include uptake inhibition and release assays in rat brain synaptosomes and in mammalian expression systems. Electrophysiological techniques include current measurements using the voltage clamp technique. We describe a Ca2+ mobilization assay wherein voltage-gated Ca2+ channels function as reporters to study the action of synthetic cathinones at monoamine transporters. We discuss results from systematic structure-activity relationship studies on simple and complex cathinones at monoamine transporters with an emphasis on identifying structural moieties that modulate potency and selectivity at these transporters. Moreover, different profiles of selectivity at monoamine transporters directly predict compounds associated with behavioral and subjective effects within animals and humans. In conclusion, clarification of the structural aspects of compounds which modulate potency and selectivity at monoamine transporters is critical to identify and predict potential addictive drugs. This knowledge may allow prompt allocation of resources toward drugs that represent the greatest threats after drugs are identified by forensic laboratories.

Efficacy of Chemotherapy Rechallenge Versus Regorafenib or Trifluridine/Tipiracil in Third-Line Setting of Metastatic Colorectal Cancer: A Multicenter Retrospective Comparative Study.

PURPOSE: Metastatic colorectal cancer (mCRC) is a significant global health burden. This retrospective study compared the effectiveness of trifluridine/tipiracil (FTD/TPI), regorafenib, and chemotherapy rechallenge for third-line mCRC treatment. MATERIALS AND METHODS: We reviewed the medical records of 132 patients with mCRC treated with regorafenib, FTD/TPI, or a rechallenge with the initial chemotherapy regimen in a third-line setting from four different institutions. The primary end point was progression-free survival (PFS). Secondary end points were objective response rate and overall survival (OS) across the three treatment approaches. RESULTS: Twenty-nine patients received chemotherapy rechallenge, and 103 received FTD/TPI or regorafenib. Patients' characteristics were comparable, except for a lower number of left-sided primaries and KRAS wild-type tumors in the FTD/TPI-regorafenib group. The median PFS for the entire group was 3.0 months, and the median OS was 13.7 months. Chemotherapy rechallenge has resulted in a median PFS of 3.1 months and a median OS of 21.2 months, compared with 2.9 months (PFS) and 12.6 months (OS) for the FTD/TPI-regorafenib group. Multivariate analyses identified male sex and an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-1 as independent prognostic factors for better PFS, whereas chemotherapy rechallenge, localized stage at diagnosis, and an ECOG PS of 0-1 were significant prognostic factors for better OS. CONCLUSION: This study suggests that chemotherapy rechallenge may provide a survival benefit in the third-line treatment of mCRC. However, patient characteristics, such as sex and ECOG PS, should also be considered in treatment decisions. Further prospective studies are required to confirm our findings.

Perceived burden of respiratory physiotherapy in people with cystic fibrosis taking elexacaftor-tezacaftor-ivacaftor combination: a 1-year observational study.

BACKGROUND: To limit the progression of disease, people with cystic fibrosis (pwCF) perform daily respiratory physiotherapy, which is perceived as the most burdensome routine in managing their condition. The elexacaftor-tezacaftor-ivacaftor (ETI) combination has changed respiratory management. OBJECTIVE: To investigate how the perceived treatment burden changed in 1 year of treatment with ETI. DESIGN: Prospective observational study. METHODS: Ad hoc questionnaires for the pwCF and for the caregivers of pwCF < 18 years were administered before the initiation of ETI therapy and then at 6-12 months. The Cystic Fibrosis Questionnaire-Revised (CFQ-R) and the Sinonasal Outcome Test (SNOT-22) were administered to explore disease-related symptoms and social limitations. The International Physical Activity Questionnaire was used to determine levels of physical activity. Mixed-effect models were fitted to explore whether the time engaged in respiratory physiotherapy changed during 1 year. RESULTS: The study included 47/184 pwCF aged 21.4 (5.7) years, who completed 1 year of ETI therapy. At 6 months, time on aerosol therapy was decreased by 2.5 (95% CI -32.9 to 27.8) min/day, time on airway clearance therapies (ACTs) was decreased by 8.8 (95% CI -25.9 to 8.3) min/day, and time for cleaning and disinfecting respiratory equipment was decreased by 10.6 (95% CI -26.5 to 5.3) min/day. At 1 year, gains in time saved were nearly 15 min/day on average. At 1 year, 5/47 (10.6%) pwCF reported that they had discontinued positive expiratory pressure mask. CONCLUSION: PwCF on ETI may note less time engaged in their daily respiratory physiotherapy routine. Nonetheless, aerosol therapy, ACTs and maintaining respiratory equipment were still perceived as time-consuming daily activities.

Understanding the challenges of respiratory physiotherapy in individuals with cystic fibrosis using triple therapy: a one-year study.In order to slow down the progression of their disease, people with cystic fibrosis typically do daily respiratory physiotherapy, which they find to be the most challenging part of managing their condition. The elexacaftor-tezacaftor-ivacaftor combination has changed how they manage their respiratory health. We wanted to see how the perceived difficulty of the treatment changed over one year of using elexacaftor-tezacaftor-ivacaftor. We gave questionnaires to people with cystic fibrosis and to their caregivers before they started the triple therapy and again at 6-12 months. We also used two international questionnaires to learn about symptoms and social limitations related to the disease. The International Physical Activity Questionnaire helped us understand their physical activity levels. We used statistical models to see if the time spent on respiratory physiotherapy changed over the year. Our study involved 47 individuals with cystic fibrosis, with an average age of 21 years, who completed one year of elexacaftor-tezacaftor-ivacaftor therapy. After 6 months, time spent on aerosol therapy decreased by 2.5 minutes per day, time on airway clearance therapies decreased by 8.8 minutes per day, and time for cleaning respiratory equipment decreased by 10.6 minutes per day. By the end of the year, they were saving almost 15 minutes per day on average. At one year, 5 out of 47 said they had stopped using the positive expiratory pressure mask. People with cystic fibrosis using elexacaftor-tezacaftor-ivacaftor may find that they spend less time on their daily respiratory physiotherapy routine. However, activities like aerosol therapy, airway clearance therapies, and maintaining respiratory equipment were still seen as time-consuming.