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1.
Gesundheitswesen ; 85(3): 158-164, 2023 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-35016252

RESUMEN

OBJECTIVE: Germany's new medical licensure act has increased the importance of general practice in academic medical education. This study gives an overview of complementary and alternative medicine in general teaching practices in Germany and their adherence to evidence-based criteria which is required in order to qualify as a teaching practice. METHODS: After a systematic search for German teaching practices, we assessed their diagnostic and therapeutic offers via their websites. We calculated the various frequencies of treatments and differentiated between evidence-based complementary medicine and alternative medicine with little to no evidence. RESULTS: Of 4102 practices, more than half offered complementary and/or alternative treatment. Most of those were treatments approved of by the German medical association. Alternative medicine was offered by 18.2% of the practices. CONCLUSION: Collective terms and conflicting evidence complicate the classification of treatments. Teaching practices offering non-evidence-based treatment raise the question whether recruitment of additional teaching practices stands at odds with the quality of medical education. Explicit offers of alternative treatment should disqualify a teaching practice as such. Controversial treatment may be taught academically and during residency with a focus on evidence-based guidelines and communication skills in order to prepare young medical practitioners for talks with their patients about the subject.


Asunto(s)
Terapias Complementarias , Educación Médica , Medicina General , Humanos , Terapias Complementarias/educación , Educación Médica/legislación & jurisprudencia , Medicina Basada en la Evidencia/educación , Medicina General/educación , Medicina General/legislación & jurisprudencia , Alemania , Enseñanza
2.
J Colloid Interface Sci ; 628(Pt A): 943-954, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-35964442

RESUMEN

HYPOTHESIS: Understanding the microscopic driving force of water wetting is challenging and important for design of materials. The relations between structure, dynamics and hydrogen bonds of interfacial water can be investigated using molecular dynamics simulations. EXPERIMENTS AND SIMULATIONS: Contact angles at the alumina (0001) and (112‾0) surfaces are studied using both classical molecular dynamics simulations and experiments. To test the superhydrophilicity, the free energy cost of removing waters near the interfaces are calculated using the density fluctuations method. The strength of hydrogen bonds is determined by their lifetime and geometry. FINDINGS: Both surfaces are superhydrophilic and the (0001) surface is more hydrophilic. Interactions between surfaces and interfacial waters promote a templating effect whereby the latter are aligned in a pattern that follows the underlying lattice of the surfaces. Translational and rotational dynamics of interfacial water molecules are slower than in bulk water. Hydrogen bonds between water and both surfaces are asymmetric, water-to-aluminol ones are stronger than aluminol-to-water ones. Molecular dynamics simulations eliminate the impacts of surface contamination when measuring contact angles and the results reveal the microscopic origin of the macroscopic superhydrophilicity of alumina surfaces: strong water-to-aluminol hydrogen bonds.


Asunto(s)
Óxido de Aluminio , Simulación de Dinámica Molecular , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Agua/química
3.
Oncologist ; 27(6): 476-486, 2022 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-35298662

RESUMEN

INTRODUCTION: Historically, high rates of actionable driver mutations have been reported in never-smokers with lung adenocarcinoma (ADC). In the era of modern, comprehensive cancer mutation sequencing, this relationship necessitates a more detailed analysis. METHODS: All Mount Sinai patients between January 1, 2015, and June 1, 2020, with a diagnosis of ADC of any stage with known smoking status who received genomic testing were included. Most patients were analyzed using the Sema4 hotspot panel or the Oncomine Comprehensive Assay version 3 next-generation sequencing (NGS) panel conducted at Sema4. Patients were considered fully genotyped if they were comprehensively analyzed for alterations in EGFR, KRAS, MET, ALK, RET, ROS1, BRAF, NTRK1-3, and ERBB2, otherwise they were considered partially genotyped. RESULTS: Two hundred and thirty-six never-smokers and 671 smokers met the above criteria. Of the never-smokers, 201 (85%) had a driver mutation with 167 (71%) considered actionable (ie, those with US Food and Drug Administration-approved agents). Among smokers, 439 (65%) had an identified driver mutation with 258 (38%) actionable (P < .0001). When comprehensively sequenced, 95% (70/74) of never-smokers had a driver mutation with 78% (58/74) actionable; whereas, for smokers, 75% (135/180) had a driver with only 47% (74/180) actionable (P < .0001). Within mutations groups, EGFR G719X and KRAS G12Cs were more common to smokers. For stage IV patients harboring EGFR-mutant tumors treated with EGFR-directed therapies, never-smokers had significantly improved OS compared to smokers (hazard ratio = 2.71; P = .025). In multivariable analysis, Asian ancestry and female sex remained significant predictors of (1) OS in stage IV patients and (2) likelihood of harboring a receptor of fusion-based driver. CONCLUSION: Comprehensive NGS revealed driver alterations in 95% of never-smokers, with the majority having an associated therapy available. All efforts should be exhausted to identify or rule out the presence of an actionable driver mutation in all metastatic lung ADC.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/patología , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Mutación , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Fumadores
4.
Prax Kinderpsychol Kinderpsychiatr ; 69(4): 353-374, 2020 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-32615894

RESUMEN

Mindfulness in Development-oriented Approaches to Substance Use Prevention and Therapy: Rationale, Design and Objectives of the Research Consortium IMAC-Mind Substance use disorders (SUD) are a major contributor to morbidity and mortality. They are typically initiated during adolescence and can have fatal implications for healthy development. Despite substantial scientific advances, there remains a need to prioritize research directed at reducing risks for SUD, particularly in vulnerable periods and populations from a developmental perspective. Research indicates that reward sensitivity, impulsivity, deficient self-regulation, and stress reactivity develop markedly in childhood and adolescence and play an important role in the initiation and maintenance of SUD. A growing number of research results suggest that these factors can be favorably influenced by mindfulness-based interventions and that mindfulness-based exercises can be successfully integrated into established prevention and treatment programs. In this paper we summarize the conceptual relationships between the development and maintenance of addiction disorders and mindfulness, discuss existing empirical findings with regard to childhood and adolescence, and present the aims, study designs and intervention models of the subprojects from the ongoing research network "IMAC-Mind: Improving Mental Health and Reducing Addiction in Childhood and Adolescence through Mindfulness: Mechanisms, Prevention and Treatment".


Asunto(s)
Salud Mental , Atención Plena , Trastornos Relacionados con Sustancias/prevención & control , Trastornos Relacionados con Sustancias/terapia , Adolescente , Conducta Adictiva/prevención & control , Conducta Adictiva/terapia , Niño , Humanos , Imidazoles
5.
J Cancer Res Clin Oncol ; 146(10): 2713-2715, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32415341

RESUMEN

OBJECTIVE: Public discussion and health-care systems worldwide have been focusing on the COVID-19 pandemic. Does it have an impact on cancer care today? MATERIALS AND METHODS: The PRIO ("Prevention and Integrative Oncology") Working Group (German Cancer Society) has initiated an online survey for physicians, medical staff and patients on April 16, 2020. Between April 16 and April 19, 47 doctors and 146 patients filled in the questionnaires. The survey is ongoing. We present the first data. RESULTS: A majority of German patients (76%) and physicians (71%) report moderate or high restriction in their daily life. A minority (patients 25%, physicians 13%) was not worried that necessary treatments or diagnostics were restricted. Organizing cancer care needs more time and efforts for 56% of all reporting doctors. 98% of all oncologists think that restriction of family visits has a negative impact on the mental health of cancer patients. Half of all participants (patients 43%, physicians 47%) expect negative consequences on the physical status of our patients. Patients feel the existing emotional stress in 34% of their physicians. 52% of physicians fear mental and/or physical longtime consequences for themselves. CONCLUSION: There is a high level of mental and physical stress triggered by the present COVID-19 management. After only a few weeks, human resources are limited. They will be the most important key for further health-care services for patients with cancer and other chronic diseases.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/epidemiología , Intervención en la Crisis (Psiquiatría) , Atención a la Salud , Brotes de Enfermedades , Neoplasias/epidemiología , Neumonía Viral/epidemiología , COVID-19 , Infecciones por Coronavirus/virología , Intervención en la Crisis (Psiquiatría)/métodos , Alemania , Humanos , Salud Mental , Servicios de Salud Mental , Neoplasias/diagnóstico , Neoplasias/psicología , Neoplasias/terapia , Pandemias , Médicos , Neumonía Viral/virología , SARS-CoV-2 , Encuestas y Cuestionarios
7.
Ophthalmology ; 127(6): 784-792, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31899035

RESUMEN

PURPOSE: To report the natural history of untreated neovascular age-related macular degeneration (nAMD) regarding subsequent macular atrophy. DESIGN: Prospective cohort within a randomized, controlled trial of oral micronutrient supplements. PARTICIPANTS: Age-Related Eye Disease Study (AREDS) participants (55-80 years) who demonstrated nAMD during follow-up (1992-2005), prior to anti-vascular endothelial growth factor (VEGF) therapy. METHODS: Color fundus photographs were collected at annual study visits and graded centrally for late age-related macular degeneration (AMD). Incident macular atrophy after nAMD was examined by Kaplan-Meier analysis and proportional hazards regression. MAIN OUTCOME MEASURES: Incident macular atrophy after nAMD. RESULTS: Of the 4757 AREDS participants, 708 eyes (627 participants) demonstrated nAMD during follow-up and were eligible. The cumulative risks of incident macular atrophy after untreated nAMD were 9.6% (standard error, 1.2%), 31.4% (standard error, 2.2%), 43.1% (standard error, 2.6%), and 61.5% (standard error, 4.3%) at 2, 5, 7, and 10 years, respectively. This corresponded to a linear risk of 6.5% per year. The cumulative risk of central involvement was 30.4% (standard error, 3.2%), 43.4% (standard error, 3.8%), and 57.0% (standard error, 4.8%) at first appearance of atrophy, 2 years, and 5 years, respectively. Geographic atrophy (GA) in the fellow eye was associated with increased risk of macular atrophy (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.17-2.49; P = 0.006). However, higher 52-single nucleotide polymorphism AMD genetic risk score was not associated with increased risk of macular atrophy (HR, 1.03; 95% CI, 0.90-1.17; P = 0.67). Similarly, no significant differences were observed according to SNPs at CFH, ARMS2, or C3. CONCLUSIONS: The rate of incident macular atrophy after untreated nAMD is relatively high, increasing linearly over time and affecting half of eyes by 8 years. Hence, factors other than anti-VEGF therapy are involved in atrophy development, including natural progression to GA. Comparison with studies of treated nAMD suggests it may not be necessary to invoke a large effect of anti-VEGF therapy on inciting macular atrophy, although a contribution remains possible. Central involvement is present in one third of eyes at the outset (similar to pure GA) and increases linearly to half at 3 years.


Asunto(s)
Neovascularización Coroidal/complicaciones , Atrofia Geográfica/epidemiología , Degeneración Macular Húmeda/complicaciones , Anciano , Anciano de 80 o más Años , Antioxidantes/administración & dosificación , Neovascularización Coroidal/diagnóstico , Neovascularización Coroidal/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Atrofia Geográfica/fisiopatología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Medición de Riesgo , Encuestas y Cuestionarios , Agudeza Visual/fisiología , Degeneración Macular Húmeda/diagnóstico , Degeneración Macular Húmeda/tratamiento farmacológico , Compuestos de Zinc/administración & dosificación
8.
Q J Exp Psychol (Hove) ; 73(2): 199-210, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31342856

RESUMEN

Drawing, as an encoding strategy for to-be-remembered words, has previously been shown to provide robust memory benefits. In the current study, we investigated the effect of drawing on false memory endorsements during a recognition test. We found that while drawing led to higher hit rates relative to writing (Experiment 1) and creating visual mental imagery (Experiment 2), it also led to higher false alarm (FA) rates to critical lures in a variant of the Deese-Roediger-McDermott (DRM) paradigm. When compared with an encoding strategy requiring listing of object features (Experiment 3), drawing led to a lower FA rate. We suggest that drawing enhances memory by promoting recollection of rich visual contextual information during retrieval, and this leads to the unintended side effect of increasing FA rates to related information.


Asunto(s)
Recuerdo Mental/fisiología , Actividad Motora/fisiología , Reconocimiento Visual de Modelos/fisiología , Desempeño Psicomotor/fisiología , Reconocimiento en Psicología/fisiología , Escritura , Adulto , Femenino , Humanos , Masculino , Adulto Joven
9.
Ophthalmology ; 126(11): 1541-1548, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31358387

RESUMEN

PURPOSE: To assess whether genotypes at 2 major loci associated with age-related macular degeneration (AMD), complement factor H (CFH), or age-related maculopathy susceptibility 2 (ARMS2), modify the response to oral nutrients for the treatment of AMD in the Age-Related Eye Disease Study 2 (AREDS2). DESIGN: Post hoc analysis of a randomized trial. PARTICIPANTS: White AREDS2 participants. METHODS: AREDS2 participants (n = 4203) with bilateral large drusen or late AMD in 1 eye were assigned randomly to lutein and zeaxanthin, omega-3 fatty acids, both, or placebo, and most also received the AREDS supplements. A secondary randomization assessed modified AREDS supplements in 4 treatment arms: lower zinc dosage, omission of ß-carotene, both, or no modification. To evaluate the progression to late AMD, fundus photographs were obtained at baseline and annual study visits, and history of treatment for late AMD was obtained at study visits and 6-month interim telephone calls. Participants were genotyped for the single-nucleotide polymorphisms rs1061170 in CFH and rs10490924 in ARMS2. Bivariate frailty models using both eyes were conducted, including a gene-supplement interaction term and adjusting for age, gender, level of education, and smoking status. The main treatment effects, as well as the direct comparison between lutein plus zeaxanthin and ß-carotene, were assessed for genotype interaction. MAIN OUTCOME MEASURES: The interaction between genotype and the response to AREDS2 supplements regarding progression to late AMD, any geographic atrophy (GA), and neovascular AMD. RESULTS: Complete data were available for 2775 eyes without baseline late AMD (1684 participants). The participants (mean age ± standard deviation, 72.1±7.7 years; 58.5% female) were followed up for a median of 5 years. The ARMS2 risk allele was associated significantly with progression to late AMD and neovascular AMD (P = 2.40 × 10-5 and P = 0.002, respectively), but not any GA (P = 0.097). The CFH risk allele was not associated with AMD progression. Genotype did not modify significantly the response to any of the AREDS2 supplements. CONCLUSIONS: CFH and ARMS2 risk alleles do not modify the response to the AREDS2 nutrient supplements with respect to the progression to late AMD (GA and neovascular AMD).


Asunto(s)
Carotenoides/administración & dosificación , Ácidos Grasos Omega-3/administración & dosificación , Degeneración Macular/tratamiento farmacológico , Degeneración Macular/genética , Proteínas/genética , Compuestos de Zinc/administración & dosificación , Anciano , Anciano de 80 o más Años , Factor H de Complemento/genética , Suplementos Dietéticos , Progresión de la Enfermedad , Método Doble Ciego , Combinación de Medicamentos , Femenino , Estudios de Asociación Genética , Estudio de Asociación del Genoma Completo , Técnicas de Genotipaje , Humanos , Luteína/administración & dosificación , Degeneración Macular/diagnóstico , Masculino , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple , Agudeza Visual/fisiología , Zeaxantinas/administración & dosificación , beta Caroteno/administración & dosificación
10.
BMC Public Health ; 19(1): 571, 2019 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-31088421

RESUMEN

BACKGROUND: Children of substance-abusing parents are at a substantial risk of developing substance-use and other mental disorders. Children involved in substance abuse - not diagnosed with substance-use problems but integrated in psychiatric treatment or youth welfare services - constitute a particular high-risk group that is in need of substance use prevention. Emerging evidence indicates that self-regulatory determinants of substance use and other mental disorders, particularly stress reactivity, are modifiable by mindfulness-based interventions, such as mindfulness-based stress reduction. METHODS: In this ongoing cluster randomised-controlled trial, a mindfulness-augmented version of the modularised evidence-based "Trampoline" programme for children affected by parental substance use problems is evaluated in a sample of 420 children who are from substance-involved families, aged from 8 to 12 and receiving non-substance-specific care in psychiatric or youth welfare services. Larger effects on adaptive stress-coping strategies (primary outcome), internalising and externalising problem behaviours and distress due to parental substance use are expected compared to the standard "Trampoline"-programme version. Mindfulness components will be added and regularly practiced for 30 min in each validated "Trampoline" module. Moreover, the feasibility of mindfulness-based interventions in psychiatric care and youth welfare services for children suffering from emotional and behavioural problems will be investigated in this study. DISCUSSION: Despite recruitment challenges, this study provides a unique opportunity to develop and test a promising addiction-specific, mindfulness-based intervention for a target group at risk, i.e. children from substance-involved families. TRIAL REGISTRATION: The trial was registered in the German Clinical Trials Register on July 16th 2018 (trial registration number (TRN): DRKS00013533 ). Any important protocol modifications are to be reported immediately. Protocol version v.2.1, 15th April 2019.


Asunto(s)
Hijo de Padres Discapacitados/psicología , Atención Plena/métodos , Trastornos Relacionados con Sustancias/prevención & control , Adolescente , Niño , Análisis por Conglomerados , Femenino , Alemania , Humanos , Masculino , Padres/psicología , Resultado del Tratamiento
11.
BMJ Case Rep ; 12(3)2019 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-30898964

RESUMEN

We describe the initial presentation, diagnostic work-up and treatment of three adult immunocompetent men who presented within a short time frame of each other to an academic medical centre with acute respiratory distress syndrome. Their presentation was found to be secondary to a large inoculum of histoplasmosis from remodelling a building with bat droppings infestation. We discuss the pathophysiology of histoplasmosis and highlight the importance of exposure history in patients with acute respiratory failure and why patients with the occupational risk of exposure to fungal inoculum should wear protective respirator gear.


Asunto(s)
Histoplasmosis/diagnóstico , Insuficiencia Respiratoria/diagnóstico por imagen , Adulto , Anciano , Antifúngicos/uso terapéutico , Histoplasma/inmunología , Histoplasmosis/complicaciones , Histoplasmosis/terapia , Humanos , Itraconazol/uso terapéutico , Masculino , Exposición Profesional/efectos adversos , Terapia por Inhalación de Oxígeno , Insuficiencia Respiratoria/etiología , Tomografía Computarizada por Rayos X , Adulto Joven
12.
J Nat Prod ; 81(5): 1154-1161, 2018 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-29676912

RESUMEN

The in vitro antidiabetic and antihyperlipidemic activities of an alcoholic extract of Trigonella stellata were evaluated in terms of the activation of PPARα and PPARγ in human hepatoma (HepG2) cells. The extract was investigated phytochemically, aiming at the isolation of the most active compounds to be used as a platform for drug discovery. Three new isoflavans, (3 S,4 R)-4,2',4'-trihydroxy)-7-methoxyisoflavan (1), (3 R,4 S)-4,2',4'-trihydroxy-7-methoxy-4'- O-ß-d-glucopyranosylisoflavan (2), and (2 S,3 R,4 R)-4,2',4'-trihydroxy-2,7-dimethoxyisoflavan (3), were isolated and characterized along with the five known compounds p-hydroxybenzoic acid (4), 7,4'-dihydroxyflavone (5), dihydromelilotoside (6), quercetin-3,7- O-α-l-dirhamnoside (7), and soyasaponin I (8). The structures of 1-3 were elucidated using various spectroscopic techniques including HRESIMS and 1D and 2D NMR. The absolute stereochemistry of the new isoflavans (1-3) was determined using both experimental and calculated electronic circular dichroism as well as DP4 calculations. The isolated compounds were tested for their PPARα and PPARγ activation effects in HepG2 cells.


Asunto(s)
Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Hipolipemiantes/química , Hipolipemiantes/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Trigonella/química , Línea Celular Tumoral , Células Hep G2 , Humanos , Espectroscopía de Resonancia Magnética/métodos , Quercetina/química , Quercetina/farmacología
13.
J Med Chem ; 60(12): 5209-5215, 2017 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-28564542

RESUMEN

Serine hydrolases are susceptible to potent reversible inhibition by boronic acids. Large collections of chemically diverse boronic acid fragments are commercially available because of their utility in coupling chemistry. We repurposed the approximately 650 boronic acid reagents in our collection as a directed fragment library targeting serine hydrolases and related enzymes. Highly efficient hits (LE > 0.6) often result. The utility of the approach is illustrated with the results against autotaxin, a phospholipase implicated in cardiovascular disease.


Asunto(s)
Ácidos Borónicos/química , Hidrolasas Diéster Fosfóricas/metabolismo , Inhibidores de Serina Proteinasa/farmacología , Bibliotecas de Moléculas Pequeñas/farmacología , Relación Estructura-Actividad , Cristalografía por Rayos X , Evaluación Preclínica de Medicamentos/métodos , Humanos , Nitrilos/química , Hidrolasas Diéster Fosfóricas/química , Hidrolasas Diéster Fosfóricas/genética , Serina Endopeptidasas/metabolismo , Inhibidores de Serina Proteinasa/química , Bibliotecas de Moléculas Pequeñas/química , Resonancia por Plasmón de Superficie
14.
Hemodial Int ; 21(4): 575-584, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-27860119

RESUMEN

Introduction The aim of this paper is to describe and demonstrate how a new bioimpedance analytical procedure can be used to monitor cellular hydration of End Stage Renal Disease (ESRD) patients during hemodialysis (HD). Methods A tetra-polar bioimpedance spectroscope (BIS), (UFI Inc., Morro Bay, CA), was used to measure the tissue resistance and reactance of the calf of 17 ESRD patients at 40 discrete frequencies once a minute during dialysis treatment. These measurements were then used to derive intracellular, interstitial, and intravascular compartment volume changes during dialysis. Findings The mean (± SD) extracellular resistance increased during dialysis from 92.4 ± 3.5 to 117.7 ± 5.8 Ohms. While the mean intracellular resistance decreased from 413.5 ± 11.7 to 348.5 ± 8.2 Ohms. It was calculated from these data that the mean intravascular volume fell 9.5%; interstitial volume fell 33.4%; and intracellular volume gained 20.3%. Discussion These results suggest that an extensive fluid shift into the cells may take place during HD. The present research may contribute to a better understanding of how factors that influence fluid redistribution may affect an ESRD patient during dialysis. In light of this finding, it is concluded that the rate of vascular refill is jointly determined with the rate of "cellular refill" and the transfer of fluid from the intertitial compartment into the intravascular space.


Asunto(s)
Impedancia Eléctrica/uso terapéutico , Hipotensión/prevención & control , Fallo Renal Crónico/terapia , Diálisis Renal/métodos , Anciano , Animales , Bovinos , Femenino , Humanos , Hipotensión/terapia , Masculino
15.
J Nat Prod ; 79(10): 2538-2544, 2016 10 28.
Artículo en Inglés | MEDLINE | ID: mdl-27754693

RESUMEN

Calea urticifolia (Asteraceae: Asteroideae) has long been used as a traditional medicine in El Salvador to treat arthritis and fever, among other illnesses. The chloroform extract of the leaves of C. urticifolia showed potent inhibition of recombinant human monoamine oxidases (MAO-A and -B). Further bioassay-guided fractionation led to the isolation of a flavonoid, acacetin, as the most prominent MAO inhibitory constituent, with IC50 values of 121 and 49 nM for MAO-A and -B, respectively. The potency of MAO inhibition by acacetin was >5-fold higher for MAO-A (0.121 µM vs 0.640 µM) and >22-fold higher for MAO-B (0.049 µM vs 1.12 µM) as compared to apigenin, the closest flavone structural analogue. Interaction and binding characteristics of acacetin with MAO-A and -B were determined by enzyme-kinetic assays, enzyme-inhibitor complex binding, equilibrium-dialysis dissociation analyses, and computation analysis. Follow-up studies showed reversible binding of acacetin with human MAO-A and -B, resulting in competitive inhibition. Acacetin showed more preference toward MAO-B than to MAO-A, suggesting its potential for eliciting selective pharmacological effects that might be useful in the treatment of neurological and psychiatric disorders. In addition, the binding modes of acacetin at the enzymatic site of MAO-A and -B were predicted through molecular modeling algorithms, illustrating the high importance of ligand interaction with negative and positive free energy regions of the enzyme active site.


Asunto(s)
Asteraceae/química , Flavonas/aislamiento & purificación , Flavonas/farmacología , Inhibidores de la Monoaminooxidasa/aislamiento & purificación , Inhibidores de la Monoaminooxidasa/farmacología , Dominio Catalítico , Relación Dosis-Respuesta a Droga , El Salvador , Flavonas/química , Humanos , Concentración 50 Inhibidora , Modelos Moleculares , Estructura Molecular , Inhibidores de la Monoaminooxidasa/química , Relación Estructura-Actividad , Factores de Tiempo
16.
JACC Clin Electrophysiol ; 2(7): 784-789, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-29759761

RESUMEN

OBJECTIVES: The aim of this study was to determine the in vitro electrophysiological properties of loperamide. The authors' hypothesis was that loperamide is a potent blocker of the current carried by the human ether-à-go-go-related gene (hERG) potassium channel. BACKGROUND: Loperamide is a peripherally-acting µ-opioid agonist available worldwide as an over-the-counter treatment for diarrhea. Like most opioids, it is not currently known to be proarrhythmic. Recent cases of torsade de pointes in association with high-dose loperamide raise concern given its structural similarity to methadone, another synthetic opioid with an established arrhythmia risk. METHODS: Effects of loperamide on blockade of the hERG potassium channel ion current were assessed in Chinese Hamster Ovary (CHO) cells stably expressing hERG to elucidate current amplitude and kinetics. The concentration required to produce 50% inhibition of hERG current was assessed from the amplitude of tail currents and the impact on action potential duration was assessed in isolated swine ventricular cardiomyocytes. RESULTS: The 50% inhibitory concentration for loperamide inhibition of hERG ionic tail currents was approximately 40 nmol/l. In current-voltage measurements, loperamide reduced steady and tail currents and shifted the current activation to more negative potentials. Loperamide (10 nmol/l) also increased the action potential duration, assessed at 90% of repolarization, in ventricular myocytes by 16.4 ± 1.7% (n = 6; p < 0.004). The maximum rate of rise of phase 0 of the action potential, however, was not significantly altered at any tested concentration of loperamide. CONCLUSIONS: Loperamide is a potent hERG channel blocker. It significantly prolongs the action potential duration and suggests a causal association between loperamide and recent clinical cases of torsade de pointes.


Asunto(s)
Antidiarreicos/farmacología , Canales de Potasio Éter-A-Go-Go/antagonistas & inhibidores , Canales de Potasio Éter-A-Go-Go/efectos de los fármacos , Loperamida/farmacología , Animales , Células CHO , Células Cultivadas , Cricetinae , Cricetulus , Ventrículos Cardíacos/citología , Humanos , Miocitos Cardíacos/citología , Miocitos Cardíacos/efectos de los fármacos , Porcinos
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