What is known and Objective: Methotrexate (MTX) is widely used in the management of paediatric cancer with a generally favourable benefit/risk profile. We report an unusual adverse drug reaction with the first course of high-dose MTX in a paediatric patient and review the literature for similar cases. Case summary: An 11-year-old boy with small-cell osteoblastic osteosarcoma in the lower limb experienced a case of life-threatening anaphylaxis during the first course of high-dose MTX. The adverse event occurred during the first course, likely due to an immune-mediated mechanism. We postulate that prior antineoplastic treatment might have contributed to the immune response to MTX. What is new and Conclusion: Given that this reaction has rarely been reported, we discuss the present case with a review of other similar cases. Further studies are needed to substantiate this ‘signal alarm’ for serious MTX-related hypersensitivity reactions.
Traumatic brain injury (mTBI) is a major public health concern, with mild TBI (mTBI) constituting the vast majority of the injuries. Post-traumatic headache (PTH) is one of the most frequent symptoms that follow a mTBI, occurring in isolation with a tension-type or migraine phenotype, or more often as part of a complex neurobehavioural array of symptoms. The existence of PTH as a separate entity from the primary headaches is still a matter of debate. Classification issues and a lack of methodologically robust epidemiological and clinical studies have made it difficult to elucidate the mechanisms underlying acute and even more persistent PTH (PPTH). Furthermore, psychiatric comorbidities such as post-traumatic stress disorder (PTSD), previous history of migraine, and legal issues often reported by PPTH patients have complicated the understanding of this condition, hence treatment approaches for PTH remain problematic. Recent findings from structural and functional neuroimaging studies have attempted to describe the brain architecture of PPTH, suggesting the involvement of different networks compared to migraine. It also seems that calcitonin gene-related peptide (CGRP) levels are not particularly raised in PPTH, although CGRP monoclonal antibodies have obtained positive initial open-label evidence of efficacy in PPTH, and more trials assessing the efficacy of this class of treatments are underway. The broad overlap between PTH, migraine, and PTSD suggests that research in this field should start with a re-appraisal of the diagnostic criteria, followed by methodologically sound epidemiological and clinical studies. Preclinical research should strive to create more reliable PTH models to support human neuroimaging, neurochemical, and neurogenetic studies, aiming to underpin new pathophysiological hypotheses that may expand treatment targets and improve the management of PTH patients.
Insufficient mesenteric perfusion is a dramatic complication in critically ill patients. Hydrogen sulfide, a newly recognized endogenous gaseous mediator, acts as an intestinal vasoactive agent and seems to protect against mesenteric ischemic damage. We investigated whether sodium hydrogen sulfide, a hydrogen sulfide donor, can improve mesenteric perfusion in an experimental model of pigs, both in physiological and ischemic conditions.The study was conducted at Careggi University Hospital (Florence, IT). Fourteen male domestic pigs (≈10 Kg) were anesthetized and mechanically ventilated. Animals were randomized in control and ischemia groups. Mesenteric ischemia was induced with a positive end-expiratory pressure of 15 cmH2O. After mini-laparotomy, each animal received incremental doses of sodium hydrogen sulfide every 20 minutes. Perfusion of both the jejunal mucosa and sternal skin were measured by laser Doppler flowmeter, and systemic hemodynamic parameters were monitored.In the control group, sodium hydrogen sulfide was able to significantly improve the mesenteric perfusion, showing a 50% increase from the baseline blood flow. In the ischemia group, NaHS-induced a two-fold increase of the mesenteric post-ischemic perfusion with a recovery up to 70% of pre- positive end-expiratory pressure mesenteric blood flow. Sodium hydrogen sulfide did not directly or indirectly (by blood flow redistribution) affect the sternal skin microcirculation, heart rates, or mean arterial pressure, suggesting a tissue-specific micro-vascular action.In a porcine model, we observed a mesenteric perfusion recovery mediated by administration of hydrogen sulfide donor without affecting general hemodynamic.
European medical students should have acquired adequate prescribing competencies before graduation, but it is not known whether this is the case. In this international multicenter study, we evaluated the essential knowledge, skills, and attitudes in clinical pharmacology and therapeutics (CPT) of final-year medical students across Europe. In a cross-sectional design, 26 medical schools from 17 European countries were asked to administer a standardized assessment and questionnaire to 50 final-year students. Although there were differences between schools, our results show an overall lack of essential prescribing competencies among final-year students in Europe. Students had a poor knowledge of drug interactions and contraindications, and chose inappropriate therapies for common diseases or made prescribing errors. Our results suggest that undergraduate teaching in CPT is inadequate in many European schools, leading to incompetent prescribers and potentially unsafe patient care. A European core curriculum with clear learning outcomes and assessments should be urgently developed.
Glyceryl trinitrate is administered as a provocative test for migraine pain. Glyceryl trinitrate causes prolonged mechanical allodynia in rodents, which temporally correlates with delayed glyceryl trinitrate-evoked migraine attacks in patients. However, the underlying mechanism of the allodynia evoked by glyceryl trinitrate is unknown. The proalgesic transient receptor potential ankyrin 1 (TRPA1) channel, expressed by trigeminal nociceptors, is sensitive to oxidative stress and is targeted by nitric oxide or its by-products. Herein, we explored the role of TRPA1 in glyceryl trinitrate-evoked allodynia. Systemic administration of glyceryl trinitrate elicited in the mouse periorbital area an early and transient vasodilatation and a delayed and prolonged mechanical allodynia. The systemic, intrathecal or local administration of selective enzyme inhibitors revealed that nitric oxide, liberated from the parent drug by aldehyde dehydrogenase 2 (ALDH2), initiates but does not maintain allodynia. The central and the final phases of allodynia were respectively associated with generation of reactive oxygen and carbonyl species within the trigeminal ganglion. Allodynia was absent in TRPA1-deficient mice and was reversed by TRPA1 antagonists. Knockdown of neuronal TRPA1 by intrathecally administered antisense oligonucleotide and selective deletion of TRPA1 from sensory neurons in Advillin-Cre; Trpa1fl/fl mice revealed that nitric oxide-dependent oxidative and carbonylic stress generation is due to TRPA1 stimulation, and resultant NADPH oxidase 1 (NOX1) and NOX2 activation in the soma of trigeminal ganglion neurons. Early periorbital vasodilatation evoked by glyceryl trinitrate was attenuated by ALDH2 inhibition but was unaffected by TRPA1 blockade. Antagonists of the calcitonin gene-related peptide receptor did not affect the vasodilatation but partially inhibited allodynia. Thus, although both periorbital allodynia and vasodilatation evoked by glyceryl trinitrate are initiated by nitric oxide, they are temporally and mechanistically distinct. While vasodilatation is due to a direct nitric oxide action in the vascular smooth muscle, allodynia is a neuronal phenomenon mediated by TRPA1 activation and ensuing oxidative stress. The autocrine pathway, sustained by TRPA1 and NOX1/2 within neuronal cell bodies of trigeminal ganglia, may sensitize meningeal nociceptors and second order trigeminal neurons to elicit periorbital allodynia, and could be of relevance for migraine-like headaches evoked by glyceryl trinitrate in humans.
