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High-quality evidence indicated that both neoadjuvant carboplatin/paclitaxel (CROSS) and cisplatin/5-fluorouracil (PF) regimens in combination with radiotherapy improve survival outcomes compared to surgery alone in patients with esophageal cancer. It is not yet known whether they may differ in terms of treatment burden and healthcare costs. A total of 232 Taiwanese patients with esophageal squamous cell carcinoma who had undergone neoadjuvant chemoradiotherapy (nCRT) with either the CROSS (n = 153) or the PF (n = 79) regimens were included. Hospital encounters and adverse events were assessed for determining treatment burden. Cost-effectiveness analysis was undertaken using the total costs incurred over 3 years in relation to overall survival (OS) and progression-free survival (PFS). Compared with PF, the CROSS regimen was associated with a lower treatment burden: shorter inpatient days on average (4.65 ± 10.05 vs. 15.14 ± 17.63 days; P < 0.001) and fewer admission requirements (70% of the patients were never admitted vs. 20% in the PF group; P < 0.001). Patients in the CROSS group experienced significantly less nausea, vomiting, and diarrhea. While the benefits observed in the CROSS group were associated with additional nCRT-related expenditures (1388 United States dollars [USD] of added cost per patient), this regimen remained cost-effective. At a willingness-to-pay threshold of 50,000 USD per life-year, the probability of the CROSS regimen to be more cost-effective than PF was 94.1% for PFS but decreased to 68.9% for OS. The use of the CROSS regimen for nCRT in patients with ESCC was associated with a lower treatment burden and was more cost-effective than PF.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Humanos , Carcinoma de Células Escamosas de Esófago/terapia , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/patología , Terapia Neoadyuvante , Análisis de Costo-Efectividad , Estudios Retrospectivos , Fluorouracilo , Cisplatino , Paclitaxel , Quimioradioterapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéuticoRESUMEN
Controlling the molecular architecture of well-organized organic building blocks and linking their functionalities with the impact of solar-light converting systems constitutes a grand challenge in materials science. Strong absorption cross-sections across the visible range of the solar spectrum as well as a finely balanced energy- and redox-gradient are all important features that pave the way for either funneling excited state energy or transducing charges. In light of this, we used thiopyridyl-phthalocyanines (PcSPy) and ruthenium (tert-butyl)-phthalocyanines (RuPc) as versatile building blocks and demonstrated the realization of a family of multi-functional PcSPy-RuPc 1-4 by means of axial coordination. Sizeable electronic couplings between the electron donors and acceptors in PcSPy-RuPc 1-4 govern ground-state as well as excited-state reactivity. Time-resolved techniques, in general, and fluorescence and transient absorption spectroscopy, in particular, helped to corroborate a rapid charge separation next to a slow charge recombination. Key to these charge transfer characteristics are higher lying, vibrationally hot states of the singlet excited states in parallel with a charge transfer state and the presence of several heavy atom effects that are provided by ruthenium and sulfur. As such, our advanced investigations confirm that rapid charge separation evolves from both higher lying, vibrationally hot states as well as from a charge transfer state, populating charge separated states, whose energies exceed those of the singlet excited states. Charge recombination involves triplet rather than singlet charge separated states, which delays the charge recombination by one order of magnitude.
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The investigation of molecular model systems is fundamental towards a deeper understanding of key photochemical steps in natural photosynthesis. Herein, we report an entirely non-covalent triad consisting of boron dipyrromethene (BDP), porphyrin (ZnP), and fullerene (C60). Non-covalent binding motifs such as an amidinium-carboxylate salt bridge as well as axial pyridyl-metal coordination offer substantial electronic coupling and establish efficient pathways for photoactivated energy and electron transfer processes along a well-tuned gradient. Experimental findings from steady-state and time-resolved spectroscopic assays, as well as (spectro-)electrochemical measurements corroborate the formation of BDP|ZnP|C60 in solution, on one hand, and significant communication in the excited states, on the other hand. BDP acts as an energy harvesting antenna towards ZnP, which eventually undergoes charge separation with C60 by electron transfer from ZnP to C60. Notably, full spectral deconvolution of the transient species was achieved, supporting the successful self-assembly as well as giving a clear view onto the occurring photophysical processes and their spectral footprints upon photoexcitation.
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BACKGROUND: The most beneficial neoadjuvant chemoradiotherapy (nCRT) combination for esophageal squamous cell carcinoma (ESCC) in Asia remains uncertain. Herein, we compared the neoadjuvant carboplatin/paclitaxel (CROSS) regimen versus the cisplatin/5-fluorouracil (PF) regimen in combination with 41.4-50.4 Gy of radiotherapy. METHODS: Patients were stratified according to their nCRT regimen: CROSS + 41.4-45.0 Gy (CROSS), PF + 45.0 Gy (PF4500) or PF + 50.4 Gy (PF5040). Propensity score matching by inverse probability of treatment weighting (IPTW) was used to balance the baseline variables. RESULTS: Before IPTW, a total of 334 patients were included. The lowest chemotherapy completion rate was observed in the PF5040 group (76.2% versus 89.4% and 92.0% in the remaining two groups, respectively). Compared with CROSS, both PF groups showed more severe weight loss during nCRT and a higher frequency of post-esophagectomy anastomotic leaks. The use of PF5040 was associated with the highest rate of pathological complete response (45.3%). While CROSS conferred a significant overall survival benefit over PF4500 (hazard ratio [HR] = 1.30, 95% CI = 1.05 to 1.62, p = 0.018), similar survival figures were observed when compared with PF5040 (HR = 1.17, 95% CI = 0.94 to 1.45, p = 0.166). CONCLUSIONS: The CROSS regimen conferred a significant survival benefit over PF4500, although the similar survival figures were similar to those observed with PF5040. Considering the lower incidences of severe weight loss and post-esophagectomy anastomotic leaks, CROSS represents a safe and effective neoadjuvant treatment for Taiwanese patients with ESCC.
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AIMS: No consensus exists on the clinical value of tumour regression grading (TRG) systems for therapy effects of neoadjuvant chemoradiotherapy (nCRT) in oesophageal adenocarcinoma. Existing TRG systems lack standardization and reproducibility, and do not consider the morphological heterogeneity of tumour response. Therefore, we aim to identify morphological tumour regression patterns of oesophageal adenocarcinoma after nCRT and their association with survival. METHODS AND RESULTS: Patients with oesophageal adenocarcinoma, who underwent nCRT followed by surgery and achieved a partial response to nCRT, were identified from two Dutch upper-gastrointestinal (GI) centres (2005-18; test cohort). Resection specimens were scored for regression patterns by two independent observers according to a pre-defined three-step flowchart. The results were validated in an external cohort (2001-17). In total, 110 patients were included in the test cohort and 115 in the validation cohort. In the test cohort, two major regression patterns were identified: fragmentation (60%) and shrinkage (40%), with an excellent interobserver agreement (κ = 0.87). Here, patients with a fragmented pattern had a significantly higher pathological stage (stages III/IV: 52 versus 16%; P < 0.001), less downstaging (48 versus 91%; P < 0.001), a higher risk of recurrence [risk ratio (RR) = 2.9, 95% confidence interval (CI) = 1.5-5.6] and poorer 5-year overall survival (30 versus 80% respectively, P = 0.001). CONCLUSIONS: The validation cohort confirmed these findings, although had more advanced cases (case-stages = III/IV 91 versus 73%, P = 0.005) and a higher prevalence of fragmented-pattern cases (80 versus 60%, P = 0.002). When combining the cohorts in multivariate analysis, the pattern of response was an independent prognostic factor [hazard ratio (HR) = 1.76, 95% CI = 1.0-3.0]. In conclusion, we established an externally validated, reproducible and clinically relevant classification of tumour response.
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Adenocarcinoma , Neoplasias Esofágicas , Adenocarcinoma/patología , Quimioradioterapia , Neoplasias Esofágicas/patología , Humanos , Terapia Neoadyuvante , Estadificación de Neoplasias , Pronóstico , Reproducibilidad de los Resultados , Resultado del TratamientoRESUMEN
Voriconazole (VRC) pharmacokinetics, in particular its complex metabolism, is still not fully understood which challenges its optimal therapeutic use. To increase knowledge on the pharmacokinetics of this antifungal drug, it is essential to broaden the perspective and expand in vitro and clinical in vivo investigations in particular to aspects such as unbound plasma, target-site and metabolite concentrations. Innovative sampling approaches such as microdialysis, a minimally-invasive technique for the analysis of compound concentrations in target-site human tissue fluids, are associated with bioanalytical challenges, i.e. small sample volumes and low concentrations. Thus, a bioanalytical LC-MS/MS assay for the simultaneous quantification of VRC and its main N-oxide (NO) metabolite in human plasma, ultrafiltrate and microdialysate was developed and validated according to the European Medicines Agency guideline. Quantification was rapid, simple and feasible for clinically relevant concentrations from 5 to 5000 ng/mL in plasma and ultrafiltrate as well as from 4 to 4000 ng/mL in microdialysate. Due to the high sensitivity of the assay, only 20 µL of plasma or ultrafiltrate and 5 µL of microdialysate were required. For VRC and NO in all matrices, between-run accuracy was high with a maximum mean deviation of 7.0% from the nominal value and between-run precision was demonstrated by ≤ 11.8% coefficient of variation. Both compounds proved stable under various conditions. The assay suitability was demonstrated by the application to a clinical study quantifying simultaneously VRC and NO concentrations in plasma, ultrafiltrate and microdialysate. Additionally, the assay was successfully adapted for pharmacokinetic analyses in human tissue-derived in vitro experiments. Overall, by reducing the required sample volume, the bioanalytical method allows for an increased number of plasma samples in vulnerable populations, e.g. infants, and enables the generation of concentration-time profiles with a higher temporal resolution in microdialysis studies. Consequently, the developed assay is apt to elucidate the complex pharmacokinetics of VRC in clinical settings as prerequisite for therapy optimisation.
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Óxidos , Espectrometría de Masas en Tándem , Cromatografía Liquida , Humanos , Microdiálisis , Reproducibilidad de los Resultados , VoriconazolRESUMEN
BACKGROUND: Although neoadjuvant therapy followed by surgery (NT) is the standard of care for esophageal cancer in Western countries, upfront surgery (US) followed by adjuvant therapy (when indicated) still is commonly used in Asia to minimize overtreatment. This study investigated the cost-effectiveness of NT versus US for patients with esophageal squamous cell carcinoma (ESCC). METHODS: Patients with a diagnosis of ESCC between 2010 and 2015 were divided into NT or US according to the intention to treat. Two propensity score-matched groups of patients with clinical stage 2 (135 pairs) or stage 3 (194 pairs) disease were identified and compared in terms of overall survival (OS) and direct costs incurred within 3 years after diagnosis. RESULTS: The esophagectomy rates after NT were 82% for stage 2 and 88% for stage 3 disease. Compared with US, surgery after NT was associated with higher R0 resection rates, a lower number of dissected lymph nodes, and similar postoperative mortality. On an intention-to-treat analysis, stage 3 patients who received NT had a significantly better 3-year OS rate (45%) than those treated with US (37%) (p = 0.029) without significant cost increases (p = 0.89). However, NT for clinical stage 2 disease neither increased costs nor improved 3-year OS rates (47% vs 47%; p = 0.88). At a willingness-to-pay level of US$50,000 per life-year, the probability of NT being cost-effective was 92% for stage 3 versus 59% for stage 2 ESCC. CONCLUSION: Because of its higher cost-effectiveness, NT is preferable to US for patients with clinical stage 3 ESCC, but US remains a viable option for stage 2 disease.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Análisis Costo-Beneficio , Neoplasias Esofágicas/cirugía , Carcinoma de Células Escamosas de Esófago/cirugía , Esofagectomía , Humanos , Terapia Neoadyuvante , Estadificación de Neoplasias , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
Modern supercritical fluid chromatography (SFC) is now a well-established technique, especially in the field of pharmaceutical analysis. We recently demonstrated the transferability and the reproducibility of a SFC-UV method for pharmaceutical impurities by means of an inter-laboratory study. However, as this study involved only one brand of SFC instrumentation (Waters®), the present study extends the purpose to multi-instrumentation evaluation. Specifically, three instrument types, namely Agilent®, Shimadzu®, and Waters®, were included through 21 laboratories (n = 7 for each instrument). First, method transfer was performed to assess the separation quality and to set up the specific instrument parameters of Agilent® and Shimadzu® instruments. Second, the inter-laboratory study was performed following a protocol defined by the sending lab. Analytical results were examined regarding consistencies within- and between-laboratories criteria. Afterwards, the method reproducibility was estimated taking into account variances in replicates, between-days and between-laboratories. Reproducibility variance was larger than that observed during the first study involving only one single type of instrumentation. Indeed, we clearly observed an 'instrument type' effect. Moreover, the reproducibility variance was larger when considering all instruments than each type separately which can be attributed to the variability induced by the instrument configuration. Nevertheless, repeatability and reproducibility variances were found to be similar than those described for LC methods; i.e. reproducibility as %RSD was around 15 %. These results highlighted the robustness and the power of modern analytical SFC technologies to deliver accurate results for pharmaceutical quality control analysis.
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Cromatografía con Fluido Supercrítico , Preparaciones Farmacéuticas , Control de Calidad , Reproducibilidad de los ResultadosRESUMEN
The objective of this work was to develop a high-performance liquid chromatographic method coupled with a mass spectrometer (LC-MS) for the simultaneous analysis of artemisinin-based drugs (e.g. artemisinin, dihydroartemisinin, artesunate, artemether) and piperaquine in formulations. Simultaneous separation of the investigated drugs was achieved in 14 min on a C18 column (2.1 mm x 100 mm, particle size 1.8 µm) using a gradient elution of 0.05 % v/v formic acid in water and acetonitrile. MS detection was done in a positive ionization mode using electrospray ionization with acquisition in a single ion monitoring mode. Proper diluent and storage time in an autosampler played significant roles on the quantitation accuracy since the target analytes possessed varied solubility and stability in aqueous and organic solvents. The method was fully validated according to ICH guideline and data showed good linearity (R > 0.999, precision (RSD < 3.89 %) and accuracy (%recovery between 98.5 and 103.7) with low limits of detection (LOD < 24.7 ng/mL) and quantitation (LOQ < 82.40 ng/mL). Validation data indicated that the developed LC-MS method is fit for the intended purpose and was successfully applied to evaluate the drug contents in formulations. Among the tested samples, the percent labeled amounts found were between 93.1 and 105.0 % and one supplement capsule contained 0.039 %w/w of artemisinin. The newly developed method could benefit both the quality control departments in pharmaceutical industries and the authorities working on falsified drug problems since official methods for the analysis of these drugs are not available in pharmacopoeias. The method is fast and environmentally friendly due to the requirement of less chemicals and production of less wastes.
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Antimaláricos , Medicamentos Falsificados , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Composición de Medicamentos , Reproducibilidad de los Resultados , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en TándemRESUMEN
In this study, a highly efficient photocatalytic H2 production system is developed by employing porphyrins as photocatalysts. Palladium and platinum tetracarboxyporphyrins (PdTCP and PtTCP) are adsorbed or coadsorbed onto TiO2 nanoparticles (NPs), which act as the electron transport medium and as a scaffold that promotes the self-organization of the porphyrinoids. The self-organization of PdTCP and PtTCP, forming H- and J-aggregates, respectively, is the key element for H2 evolution, as in the absence of TiO2 NPs no catalytic activity is detected. Notably, J-aggregated PtTCPs are more efficient for H2 production than H-aggregated PdTCPs. In this approach, a single porphyrin, which self-organizes onto TiO2 NPs, acts as the light harvester and simultaneously as the catalyst, whereas TiO2 serves as the electron transport medium. Importantly, the concurrent adsorption of PdTCP and PtTCP onto TiO2 NPs results in the most efficient catalytic system, giving a turnover number of 22,733 and 30.2 mmol(H2 ) g(cat)-1 .
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In the scientific race to build up photoactive electron donor-acceptor systems with increasing efficiencies, little is known about the interplay of their building blocks when integrated into supramolecular nanoscale arrays, particularly in aqueous environments. Here, we describe an aqueous donor-acceptor ensemble whose emergence as a nanoscale material renders it remarkably stable and efficient. We have focused on a tetracationic zinc phthalocyanine (ZnPc) featuring pyrenes, which shows an unprecedented mode of aggregation, driven by subtle cooperation between electrostatic and π-π interactions. Our studies demonstrate monocrystalline growth in solution and a symmetry-breaking intermolecular charge transfer between adjacent ZnPcs upon photoexcitation. Immobilizing a negatively charged fullerene (C60 ) as electron acceptor onto the monocrystalline ZnPc assemblies was found to enhance the overall stability, and to suppress the energy-wasting charge recombination found in the absence of C60 . Overall, the resulting artificial photosynthetic model system exhibits a high degree of preorganization, which facilitates efficient charge separation and subsequent charge transport.
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Epidemics have traditionally been viewed as the widespread occurrence of infectious disease within a community, or a sudden increase above what is typical. But modern epidemics are both more and less than the diffusion of viral entities. We argue that epidemics are 'fire objects', using a term coined by Law and Singleton: They generate locative fears through encounters that focus attention on entities that are unknown or imprecisely known, transforming spaces and humans into indeterminate dangers, alternating appearance and absence. The Ebola epidemic of 2014 had more complex impacts than the number of infections would suggest. We employ multi-sited qualitative interviews to argue that locative fear is the essence of modern global epidemics. In the discussion we contrast Ebola with both the Zika epidemic that followed and the ongoing coronavirus (COVID-19) pandemic.
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Epidemias , Miedo , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/psicología , COVID-19 , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/psicología , Salud Global , Humanos , Tecnología de la Información , Pandemias , Neumonía Viral/epidemiología , Neumonía Viral/psicología , Investigación Cualitativa , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/psicologíaRESUMEN
Cancer treatment often lacks individual dose adaptation, contributing to insufficient efficacy and severe side effects. Thus, personalized approaches are highly desired. Although various analytical techniques are established to determine drug levels in preclinical models, they are limited in the automated real-time acquisition of pharmacokinetic profiles. Therefore, an online UHPLC-MS/MS system for quantitation of drug concentrations within 3D tumor oral mucosa models was generated. The integration of sampling ports into the 3D tumor models and their culture inside the autosampler allowed for real-time pharmacokinetic profiling without additional sample preparation. Docetaxel quantitation was validated according to EMA guidelines. The tumor models recapitulated the morphology of head-and-neck cancer and the dose-dependent tumor reduction following docetaxel treatment. The administration of four different docetaxel concentrations resulted in comparable courses of concentration versus time curves for 96 h. In conclusion, this proof-of-concept study demonstrated the feasibility of real-time monitoring of drug levels in 3D tumor models without any sample preparation. The inclusion of patient-derived tumor cells into our models may further optimize the pharmacotherapy of cancer patients by efficiently delivering personalized data of the target tissue.
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The polyhydroxylated phytosteroid ecdysterone is present in various plants (e.g. spinach). It is widely marketed as the active component of dietary supplements, due to its reported health and performance promoting effects. For evaluation of its actual bioavailability, a fast and sensitive method was developed, optimized and validated for human serum. Instrumental analysis was performed utilizing liquid chromatography-tandem mass spectrometry with positive electrospray ionization and acquisition in multiple reaction mode. Solid phase extraction and dilute-and-inject (following protein precipitation) were tested to isolate ecdysterone from human serum. Both methods were compared in the light of the preset analytical target profile. The limit of detection (LOD) and quantitation (LOQ) for ecdysterone in human serum after SPE extraction corresponded to 0.06 ng/mL and 0.14 ng/mL, respectively, meeting the requested sensitivity of the method. The assay was linear over the range of 0.10 ng/mL to 20.83 ng/mL. As expected, the sensitivity of the SPE method was better than that of the dilute-and-inject procedure, which did not allow for quantitation of all post administration serum samples. Accuracy (relative error; %) and precision (coefficient of variation; %), were both within acceptance criteria (<15%). The developed method was successfully applied to a ten week intervention study conducted in young men performing regular resistance training. Different doses of supplements containing ecdysterone from spinach extract have been administered during the study and the quantitation of ecdysterone in serum samples has been successfully conducted. Ecdysterone could be quantified in all post-administration samples using solid phase extraction (SPE) for sample pretreatment.
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Ecdisterona/sangre , Extractos Vegetales/sangre , Cromatografía Liquida , Suplementos Dietéticos , Ecdisterona/administración & dosificación , Ecdisterona/química , Voluntarios Sanos , Humanos , Masculino , Conformación Molecular , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Extracción en Fase Sólida , Spinacia oleracea/química , Espectrometría de Masas en TándemRESUMEN
Here, the ability of a novel near-infrared dye to noncovalently self-assemble onto the surface of single-walled carbon nanotubes (SWCNTs) driven by charge-transfer interactions is demonstrated. Steady-state, Raman, and transient absorption spectroscopies corroborate the electron donating character of the near-infrared dye when combined with SWCNTs, in the form of fluorescence quenching of the excited state of the dye, n-doping of SWCNTs, and reversible charge transfer, respectively. Formation of the one-electron oxidized dye as a result of interactions with SWCNTs is supported by spectroelectrochemical measurements. The ultrafast electronic process in the near-infrared dye, once immobilized onto SWCNTs, starts with the formation of excited states, which decay to the ground state via the intermediate population of a fully charge-separated state, with characteristic time constants for the charge separation of 1.5 ps and charge recombination of 25 ps, as derived from the multiwavelength global analysis. Of great relevance is the fact that charge-transfer occurs from the hot excited state of the near-infrared dye to SWCNTs.
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The present study aimed to design, develop, and optimize an analytical procedure to perform the quantitative determination of ecdysterone in commercially available dietary supplements. The newly developed procedure is based on the extraction of ecdysterone from the supplements and the subsequent analysis by an optimized UHPLC-MS/MS method. Chromatographic separation was performed on an Agilent Eclipse Plus C18 column (2.1â¯mmâ¯xâ¯100â¯mm, particle size 1.8⯵m). The mass spectrometer was operated in positive ionization mode (ESI+) with acquisition in dynamic multiple reaction monitoring (dMRM) mode. Using the protonated molecular ion [M+H]+ ecdysterone (target) and cortisol (internal reference) were detected at m/z 481 and 363, respectively. The assay was fully validated according to ICH guidelines and the method resulted to be fit for purpose in terms of accuracy and precision (CV% and RE% <15). Time-different intermediate precision was found within the reported range according to AOAC guideline for dietary supplements and botanicals. Quantitation has been performed using an external calibration considering the minimal matrix influences, preliminarily assessed following a cross comparison with an elaborate and time consuming standard addition method. The method was successfully applied to 12 different dietary supplements labelled to contain ecdysterone, showing an actual content generally much lower than the labelled one.
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Suplementos Dietéticos/análisis , Etiquetado de Medicamentos/normas , Ecdisterona/análisis , Control de Calidad , Cromatografía Líquida de Alta Presión/métodos , Suplementos Dietéticos/normas , Reproducibilidad de los Resultados , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masas en Tándem/métodosRESUMEN
Cytochrome P450 enzymes (CYPs) are capable of catalyzing regio- and stereo-specific oxy functionalization reactions, which otherwise are major challenges in organic chemistry. In order to make the best possible use of these biocatalysts it is imperative to understand their specificities. Human CYP21A2 (steroid 21-hydroxylase) acts on the side-chain attached to C-17 in ring D of a steroid substrate, but the configuration of ring A also plays a prominent role in substrate cognition. Here, we comprehensively investigated this relationship using sixteen 17,17-dimethyl-18-nor-13-ene steroids with different arrangements of hydroxy-, oxo-, fluoro- and chloro-groups and in the presence or absence of double bonds (Δ1 and/or Δ4) and heteroatoms in ring A. The results show that presence of a 3-oxo group is a strict requirement for a CYP21A2 substrate, while the other configurations tested were all tolerated. This was also confirmed by control experiments using endogenous steroids. While progesterone and 17-hydroxyprogesterone were hydroxylated at C-21, (17-hydroxy-) pregnenolone did not react. Molecular docking experiments indicate that the interaction of the carbonyl group at C-3 to the side-chain Arg234 of the enzyme is indispensable.
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Modelos Moleculares , Esteroide 21-Hidroxilasa/metabolismo , Esteroides/metabolismo , Humanos , Dinámicas Mitocondriales/genética , Esteroide 21-Hidroxilasa/genética , Especificidad por SustratoRESUMEN
Oxidation of monoclonal antibodies (mAbs) can impact their efficacy and may therefore represent critical quality attributes (CQA) that require evaluation. To complement classical CQA, bevacizumab and infliximab were subjected to oxidative stress by H2O2 for 24, 48, or 72 h to probe their oxidation susceptibility. For investigation, a middle-up approach was used utilizing liquid chromatography hyphenated with mass spectrometry (LC-QTOF-MS). In both mAbs, the Fc/2 subunit was completely oxidized. Additional oxidations were found in the light chain (LC) and in the Fd' subunit of infliximab, but not in bevacizumab. By direct comparison of methionine positions, the oxidized residues in infliximab were assigned to M55 in LC and M18 in Fd'. The forced oxidation approach was further exploited for comparison of respective biosimilar products. Both for bevacizumab and infliximab, comparison of posttranslational modification profiles demonstrated high similarity of the unstressed reference product (RP) and the biosimilar (BS). However, for bevacizumab, comparison after forced oxidation revealed a higher susceptibility of the BS compared to the RP. It may thus be considered a useful tool for biopharmaceutical engineering, biosimilarity assessment, as well as for quality control of protein drugs.
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Recent studies suggest that the anabolic effect of ecdysterone, a naturally occurring steroid hormone claimed to enhance physical performance, is mediated by estrogen receptor (ER) binding. In comparison with the prohibited anabolic agents (e.g., metandienone and others), ecdysterone revealed to be even more effective in a recent study performed in rats. However, scientific studies in humans are very rarely accessible. Thus, our project aimed at investigating the effects of ecdysterone-containing products on human sport exercise. A 10-week intervention study of strength training of young men (n = 46) was carried out. Different doses of ecdysterone-containing supplements have been administered during the study to evaluate the performance-enhancing effect. Analysis of blood and urine samples for ecdysterone and potential biomarkers of performance enhancement has been conducted. To ensure the specificity of the effects measured, a comprehensive screening for prohibited performance-enhancing substances was also carried out. Furthermore, the administered supplement has been tested for the absence of anabolic steroid contaminations prior to administration. Significantly higher increases in muscle mass were observed in those participants that were dosed with ecdysterone. The same hypertrophic effects were also detected in vitro in C2C12 myotubes. Even more relevant with respect to sports performance, significantly more pronounced increases in one-repetition bench press performance were observed. No increase in biomarkers for liver or kidney toxicity was noticed. These data underline the effectivity of an ecdysterone supplementation with respect to sports performance. Our results strongly suggest the inclusion of ecdysterone in the list of prohibited substances and methods in sports in class S1.2 "other anabolic agents".