RESUMEN
The increased fragmentation caused by harsher ionization methods used during mass spectrometry such as electron ionization can make interpreting the mass spectra of peptides difficult. Therefore, the development of tools to aid in this spectral analysis is important in utilizing these harsher ionization methods to study peptides, as these tools may be more accessible to some researchers. We have compiled fragmentation mechanisms described in the literature, confirmed them experimentally, and used them to create a Python-based fragment prediction model for peptides analyzed under direct exposure probe electron ionization mass spectrometry. This initial model has been tested using single amino acids as well as targeted libraries of short peptides. It was found that the model does well in predicting fragments of peptides composed of amino acids for which the model is well-defined, but several cases where additional mechanistic information needs to be incorporated have been identified.
Asunto(s)
Aminoácidos , Fragmentos de Péptidos , Fragmentos de Péptidos/metabolismo , Aminoácidos/química , Electrones , Espectrometría de Masas/métodos , Péptidos/química , Espectrometría de Masa por Ionización de Electrospray/métodosRESUMEN
Despite multiple available treatments for bipolar depression (BD), many patients face sub-optimal responses. Transcranial direct current stimulation (tDCS) has been advocated in the management of different conditions, including BD, especially in treatment-resistant cases. The optimal dose and timing of tDCS, the mutual influence with other concurrently administered interventions, long-term efficacy, overall safety, and biological underpinnings nonetheless deserve additional assessment. The present study appraised the existing clinical evidence about tDCS for bipolar depression, delving into the putative biological underpinnings with a special emphasis on cellular and molecular levels, with the ultimate goal of providing a translational perspective on the matter. Two separate systematic reviews across the PubMed database since inception up to August 8th 2022 were performed, with fourteen clinical and nineteen neurobiological eligible studies. The included clinical studies encompass 207 bipolar depression patients overall and consistently document the efficacy of tDCS, with a reduction in depression scores after treatment ranging from 18% to 92%. The RCT with the largest sample clearly showed a significant superiority of active stimulation over sham. Mild-to-moderate and transient adverse effects are attributed to tDCS across these studies. The review of neurobiological literature indicates that several molecular mechanisms may account for the antidepressant effect of tDCS in BD patients, including the action on calcium homeostasis in glial cells, the enhancement of LTP, the regulation of neurotrophic factors and inflammatory mediators, and the modulation of the expression of plasticity-related genes. To the best of our knowledge, this is the first study on the matter to concurrently provide a synthesis of the clinical evidence and an in-depth appraisal of the putative biological underpinnings, providing consistent support for the efficacy, safety, and tolerability of tDCS.
Asunto(s)
Trastorno Bipolar , Estimulación Transcraneal de Corriente Directa , Humanos , Trastorno Bipolar/terapia , Bases de Datos Factuales , Antagonistas de Hormonas , Mediadores de InflamaciónRESUMEN
Patients with autism spectrum disorder (ASD) display distinctive neurophysiological characteristics associated with significant cognitive, emotional, and behavioral symptoms. Transcranial direct current stimulation (tDCS) applied to the frontal or temporoparietal lobes has demonstrated potential to reduce the severity of ASD-related symptoms. Recently, the cerebellum has been identified as a brain area involved in ASD pathophysiology. In this open-label pilot study, seven ASD patients aged between 9 and 13 years underwent 20 daily sessions of 20 min cathodal stimulation of the right cerebellar lobe. At the end of the treatment, the Aberrant Behavior Checklist (ABC) scores showed a 25% mean reduction in global severity of symptoms, with a more pronounced reduction in the "social withdrawal and lethargy" (-35%), "hyperactivity and noncompliance" (-26%), and "irritability, agitation, and crying" (-25%) subscales. Minor and no improvement were observed in the "stereotypic behavior" (-18%) and "inappropriate speech" (-0%) subscales, respectively. Improvements were not detected in the two patients who were taking psychotropic drugs during the study. Clinical response showed a symptom-specific time course. Quality of sleep and mood improved earlier than hyperactivity and social withdrawal. The treatment was generally accepted by patients and well tolerated. No serious adverse events were reported. Stimulation also appeared to markedly reduce the severity of tics in a patient with comorbid tic disorder and led to the disappearance of a frontal epileptogenic focus in another patient with a history of seizures. In conclusion, cerebellar tDCS is safe, feasible, and potentially effective in the treatment of ASD symptoms among children. Strategies to improve recruitment and retention are discussed.
RESUMEN
Obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD), and anxiety disorders share the basic clinical feature of anxiety, which probably explains their common response to similar pharmacological and psychological interventions. Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has proved effective in reducing the symptoms of a number of neuropsychiatric disorders. It was also used in healthy subjects to modulate neuropsychological processes that are involved in the pathophysiology of anxiety. We review the published studies in which tDCS was administered to patients with OCD, PTSD, or anxiety disorders. Our systematic search in the major electronic databases resulted in 14 articles for OCD, 1 for an OCD-related disorder (ie, hoarding disorder), 2 for PTSD, and 2 for anxiety disorders. In the studies involving OCD patients, tDCS was targeted to either the dorsolateral prefrontal cortex or the orbitofrontal cortex or the pre-supplementary motor area and induced a clear reduction of obsessive-compulsive symptoms. However, the lack of sham control groups and the great diversity in sample selection and tDCS protocols among studies prevent us from generalizing these results. In the studies involving PTSD and anxiety disorders patients, tDCS was applied over the dorsolateral prefrontal cortex and reduced symptoms, but the number of treated patients is too little to draw any conclusion on efficacy. However, these reports highlighted the importance of combining tDCS with different procedures, including computerized tasks and behavioral paradigms. In conclusion, even in its infancy, the use of tDCS for the treatment of OCD, PTSD, and anxiety disorders does show promise and deserves extensive research effort.
Asunto(s)
Trastornos de Ansiedad/terapia , Trastorno Obsesivo Compulsivo/terapia , Trastornos por Estrés Postraumático/terapia , Estimulación Transcraneal de Corriente Directa/métodos , Trastornos de Ansiedad/psicología , Humanos , Trastorno Obsesivo Compulsivo/psicología , Trastornos por Estrés Postraumático/psicologíaRESUMEN
Aripiprazole is an atypical antipsychotic drug with a polypharmacological mechanism of action and a favorable tolerability profile. Its major indications are schizophrenia and mania in adults and adolescents. Here we present the case of a 43-year-old Caucasian man with schizophrenia who developed atrial fibrillation (AF) after starting aripiprazole treatment. Prior to this treatment, he had never received any antipsychotic drugs. On admission to our inpatient unit, he showed severe psychotic symptoms and was started on aripiprazole with a rapid titration regimen (15 mg on the first day and then 15 mg twice daily thereafter) in combination with lorazepam (2.5 mg thrice a day). On the third day, the patient exhibited vomiting and an irregular pulse. An electrocardiogram (ECG) revealed new-onset AF with rapid ventricular response. Aripiprazole was discontinued and cardioversion was obtained with intravenous amiodarone. A different antipsychotic treatment was thus started (perphenazine 12 mg/d), which led to symptom remission without any relevant adverse effects. During the 2-year follow-up observation, neither psychotic symptoms nor ECG abnormalities were detected. Besides aripiprazole, other co-occurring factors might have contributed to the onset of AF in our patient, namely hypertension, low-grade diastolic dysfunction, chronic inflammatory disease, CYP2D6 polymorphism, corticosteroid and antiulcer treatment, and a family loading for myocardial infarction. In conclusion, our case study suggests that although aripiprazole has fewer cardiovascular effects than other antipsychotic drugs, in the presence of concomitant risk factors, high dose, and rapid titration regimen, regular monitoring of clinical parameters and ECG is highly recommended. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Asunto(s)
Amiodarona/administración & dosificación , Aripiprazol , Fibrilación Atrial , Cardioversión Eléctrica/métodos , Esquizofrenia , Adulto , Antiarrítmicos/administración & dosificación , Antipsicóticos/administración & dosificación , Antipsicóticos/efectos adversos , Aripiprazol/administración & dosificación , Aripiprazol/efectos adversos , Fibrilación Atrial/inducido químicamente , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/terapia , Sustitución de Medicamentos , Electrocardiografía/métodos , Humanos , Masculino , Escalas de Valoración Psiquiátrica , Factores de Riesgo , Esquizofrenia/diagnóstico , Esquizofrenia/tratamiento farmacológico , Esquizofrenia/fisiopatología , Resultado del TratamientoRESUMEN
In this study we evaluated the role of a candidate gene for major psychosis, Sialyltransferase (ST8SIA2), in the risk to develop a schizophrenia spectrum disorders, taking into account exposure to stressful life events (SLEs). Eight polymorphisms (SNPs) were tested in 94 Schizophreniainpatients and 176 healthy controls. Schizophrenia patients were also evaluated for SLEs in different life periods. None of the SNPs showed association with schizophrenia. Nevertheless, when crossing genetic variants with childhood SLEs, we could observe trends of interaction with age of onset. Though several limitations, our results support a protective role of ST8SIA2 in individuals exposed to moderate childhood stress.
RESUMEN
The Ease of Language Understanding model (Rönnberg et al., 2013) predicts that decreasing the distinctness of language stimuli increases working memory load; in the speech domain this notion is supported by empirical evidence. Our aim was to determine whether such an over-additive interaction can be generalized to sign processing in sign-naïve individuals and whether it is modulated by experience of computer gaming. Twenty young adults with no knowledge of sign language performed an n-back working memory task based on manual gestures lexicalized in sign language; the visual resolution of the signs and working memory load were manipulated. Performance was poorer when load was high and resolution was low. These two effects interacted over-additively, demonstrating that reducing the resolution of signed stimuli increases working memory load when there is no pre-existing semantic representation. This suggests that load and distinctness are handled by a shared amodal mechanism which can be revealed empirically when stimuli are degraded and load is high, even without pre-existing semantic representation. There was some evidence that the mechanism is influenced by computer gaming experience. Future work should explore how the shared mechanism is influenced by pre-existing semantic representation and sensory factors together with computer gaming experience.
RESUMEN
Antibiotics are the therapeutic agents most often associated with hepatotoxicity. However, this is mainly due to the widespread prescription of these drugs. The relative risk of antibiotic-related hepatotoxicity is low. Causality assessment of suspected drug-induced liver injury (DILI) related to antibiotics can be difficult, particularly because some cases occur long after the drug has been stopped. Among the penicillins, amoxicillin clavulanate is the most associated with hepatotoxicity and is the most frequent cause of DILI-related hospitalisations. Flucloxacillin ranks as the second highest cause of DILI in many countries. The severity of antibiotic-induced DILI varies widely, with the hepatitis-like (hepatocellular) damage tending to be more severe that than cholestatic/mixed type. The pattern is strongly influenced by age. Recently telithromycin (a new generation macrolide) has been linked with DILI, with a typical pattern, which includes abrupt commencement of fever, abdominal pain, jaundice and, in some cases, ascites. Antibiotic-induced DILI appears, in most instances, to be idiosyncratic. Genetic-association studies have recently identified genotypes related to flucloxacillin and possibly to amoxicillin-clavulanate hepatotoxicity.
Asunto(s)
Antibacterianos/efectos adversos , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Animales , Antibacterianos/uso terapéutico , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/fisiopatología , Genotipo , Humanos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de TiempoRESUMEN
Los fármacos inmunosupresores se encuentran entre los agentes farmacológicos con mayor potencial teórico de causar reacciones adversas, aunque la inducción de toxicidad hepática es una paradoja desde el punto de vista patogénico, toda vez que la respuesta del sistema inmunitario innato y adquirido se considera un episodio clave en la secuencia de acontecimientos que dan como resultado una lesión hepática de naturaleza química. La toxicidad hepática de los fármacos inmunosupresores es difícil de evaluar, ya que a veces se usan para tratar enfermedades hepáticas o junto con otros medicamentos que también pueden producir toxicidad hepática o se emplean en el contexto del trasplante hepático, en el que el rechazo o las complicaciones biliares pueden actuar como factores de confusión. Por otra parte, el tratamiento inmunosupresor puede favorecer la aparición de infecciones, que por sí mismas pueden causar daño hepático, o bien reactivar una hepatitis crónica viral latente. Los corticoides y los agentes inhibidores de la calcineurina excepcionalmente causan toxicidad hepática. El metotrexato a dosis elevadas y en pacientes con factores de riesgo puede inducir fibrosis avanzada y cirrosis. Los agentes tiopurínicos pueden ocasionar un espectro de lesiones hepáticas, incluyendo lesión hepatocelular o colestásica y alteraciones vasculares hepáticas. La leflunomida exhibe un elevado potencial hepatotóxico, especialmente si se combina con metotrexato. Los agentes antifactor de necrosis tumoral α se han asociado a toxicidad hepática en raras ocasiones, a menudo con autoanticuerpos detectables, y la mayoría de las reacciones, algunas de ellas graves, se han vinculado con infliximab, especialmente cuando se usa en pacientes con enfermedades reumatológi (AU)
Immunosuppressants are among the pharmacological agents with the greatest potential to cause adverse reactions, although induction of hepatotoxicity is paradoxical from the pathogenic point of view, since the response of the innate and acquired immune system is a key element in the chain of events leading to chemical liver damage.Hepatotoxicity induced by immunosuppressants is difficult to evaluate since these drugs are sometimes used to treat liver diseases, or in combination with other drugs that can also cause hepatotoxicity, or in the context of liver transplantation, in which rejection or biliary complications can act as confounding factors. In addition, immunosuppressant therapy can favor the development of infections, which by themselves can cause liver damage, or reactivate latent chronic viral hepatitis. Corticosteroids and calcineurin inhibitors only exceptionally cause hepatotoxicity.Methotrexate at high doses and in patients with risk factors can induce advanced fibrosis and cirrhosis. Thiopurine agents can cause a spectrum of hepatic lesions, including hepatocellular of cholestatic lesions, and hepatic vascular alterations. Leflunomide has high hepatotoxic potential, especially when combined with methotrexate. Anti-tumor necrosis factor-alpha agents have rarely been associated with hepatotoxicity, often with detectable autoantibodies, and most of the reactions some severe have been linked to infliximab, especially when used in patients with rheumatological diseases(AU)
Asunto(s)
Humanos , Hepatitis/etiología , Inmunosupresores/efectos adversos , Azatioprina/efectos adversos , Ciclosporina/efectos adversos , Metotrexato/efectos adversos , Factor de Necrosis Tumoral alfa/antagonistas & inhibidoresRESUMEN
Immunosuppressants are among the pharmacological agents with the greatest potential to cause adverse reactions, although induction of hepatotoxicity is paradoxical from the pathogenic point of view, since the response of the innate and acquired immune system is a key element in the chain of events leading to chemical liver damage. Hepatotoxicity induced by immunosuppressants is difficult to evaluate since these drugs are sometimes used to treat liver diseases, or in combination with other drugs that can also cause hepatotoxicity, or in the context of liver transplantation, in which rejection or biliary complications can act as confounding factors. In addition, immunosuppressant therapy can favor the development of infections, which by themselves can cause liver damage, or reactivate latent chronic viral hepatitis. Corticosteroids and calcineurin inhibitors only exceptionally cause hepatotoxicity. Methotrexate at high doses and in patients with risk factors can induce advanced fibrosis and cirrhosis. Thiopurine agents can cause a spectrum of hepatic lesions, including hepatocellular of cholestatic lesions, and hepatic vascular alterations. Leflunomide has high hepatotoxic potential, especially when combined with methotrexate. Anti-tumor necrosis factor-alpha agents have rarely been associated with hepatotoxicity, often with detectable autoantibodies, and most of the reactions - some severe - have been linked to infliximab, especially when used in patients with rheumatological diseases.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Inmunosupresores/efectos adversos , Azatioprina/efectos adversos , Ciclosporina/efectos adversos , Humanos , Isoxazoles/efectos adversos , Leflunamida , Metotrexato/efectos adversos , Factor de Necrosis Tumoral alfa/antagonistas & inhibidoresRESUMEN
AIMS: Aim of this observational study is to evaluate the clinical performance of a Syncope Unit, in order to assess whether the implemented organization really improves syncope management. METHODS AND RESULTS: The study enrolled patients with unexplained syncope who were consecutively referred to our Syncope Unit, either as outpatients or during hospitalization, in a 2-month period. The design of this observational study consists in three phases: a retrospective analysis of their clinical management in the 9 months prior to the first attendance at the Syncope Unit (phase one), their subsequent clinical management in the Syncope Unit (phase two) and a 9-month follow-up (phase three). The retrospective analysis of phase one showed that 25% of patients had already been hospitalized without diagnosis. After Syncope Unit evaluation, diagnosis was obtained in 82% of patients, with 15% of patients indicated to pacing. In the follow-up, 23% of patients experienced a syncopal recurrence. Our analysis indicated an 85% reduction of hospital costs in the follow-up period. CONCLUSION: The clinical and economic analysis of the three phases of our study demonstrates that a Syncope Unit allows an improved management of patients with syncope.