[A Narrative Review on Shock in the Emergency Room]. / Revisão Narrativa sobre Choque na Sala de Emergência.

The patient in shock represents a common clinical challenge in the emergency room, and potentially represents an immediate lifethreatening situation that requires the intervention of different medical specialties in order for hemodynamic stabilization to be achieved. This paper reports a non-systematic review of the initial approach to the patient in shock, highlighting the adaptation of the instituted measures to the particularities of the emergency room environment. This review is structured according to a proposed protocol of action based on the early diagnosis of shock, the identification of the type of shock and the most likely cause, and the institution of supportive therapy. The initial stabilization of the patient should be guided by the identification of failing physiological mechanisms, having in mind that strategies with little meaning in other contexts may be of interest in the emergency room - as they are practical and can be rapidly implemented - as is the case with the administration of vasoactive drugs in bolus or by peripheral access.

O doente em choque representa um desafio clínico comum na sala de emergência, e representa uma potencial situação de risco de vida imediato que requer a intervenção de diferentes especialidades médicas na sua estabilização. Neste trabalho realiza-se uma revisão não sistemática de recomendações internacionais e de literatura adicional sobre este tema, sob a perspectiva da abordagem ao doente na sala de emergência e das particularidades deste contexto. Esta revisão é estruturada segundo uma proposta de protocolo de actuação baseada no diagnóstico precoce do quadro de choque, na identificação do tipo de choque e da etiologia mais provável, bem como na instituição de terapêutica de suporte. É destacada a importância da estabilização inicial do doente ser orientada pela identificação dos mecanismos fisiológicos em falência, e identificadas estratégias que, fazendo pouco sentido noutros contextos, podem ter interesse na sala de emergência - dado serem práticas e de rápida implementação - como é o caso da administração defármacos vasoactivos por via periférica ou em bólus.

Identification of antiparkinsonian drugs in the 6-hydroxydopamine zebrafish model.

Parkinson's disease (PD) is known as a movement disorder due to characteristic motor features. Existing therapies for PD are only symptomatic, and their efficacy decreases as disease progresses. Zebrafish, a vertebrate in which parkinsonism has been modelled, offers unique features for the identification of molecules with antiparkinsonian properties. Here, we developed a screening assay for the selection of neuroactive agents with antiparkinsonian potential. First, we performed a pharmacological validation of the phenotypes exhibited by the 6-hydroxydopamine zebrafish model, by testing the effects of known antiparkinsonian agents. These drugs were also tested for disease-modifying properties by whole mount immunohistochemistry to TH+ neurons and confocal microscopy in the dopaminergic diencephalic cluster of zebrafish. Next, we optimized a phenotypic screening using the 6-hydroxydopamine zebrafish model and tested 1600 FDA-approved bioactive drugs. We found that 6-hydroxydopamine-lesioned zebrafish larvae exhibit bradykinetic and dyskinetic-like behaviours that are rescued by the administration of levodopa, rasagiline, isradipine or amantadine. The rescue of dopaminergic cell loss by isradipine was also verified, through the observation of a higher number of TH+ neurons in 6-OHDA-lesioned zebrafish larvae treated with this compound as compared to untreated lesioned larvae. The phenotypic screening enabled us to identify several compounds previously positioned for PD, as well as, new molecules with potential antiparkinsonian properties. Among these, we selected stavudine, tapentadol and nabumetone as the most promising candidates. Our results demonstrate the functional similarities of the motor impairments exhibited by 6-hydroxydopamine-lesioned zebrafish with mammalian models of PD and with PD patients, and highlights novel molecules with antiparkinsonian potential.

Tapentadol Prevents Motor Impairments in a Mouse Model of Dyskinesia.

The motor features in Parkinson's disease (PD) are associated with the degeneration of dopaminergic cells in the substantia nigra in the brain. Thus, the gold-standard in PD therapeutics still consists of dopamine replacement with levodopa. However, as the disease progresses, this therapeutic option becomes less effective and can be accompanied by levodopa-induced complications. On the other hand, several other neuronal pathways have been implicated in the pathological mechanisms of PD. In this context, the development of alternative therapeutic options that modulate non-dopaminergic targets is emerging as a major goal in the field. In a phenotypic-based screen in a zebrafish model of PD, we identified tapentadol as a candidate molecule for PD. The therapeutic potential of an agent that modulates the opioid and noradrenergic systems has not been explored, despite the implication of both neuronal pathways in parkinsonism. Therefore, we assessed the therapeutic properties of this µ-opioid receptor agonist and norepinephrine reuptake inhibitor in the 6-hydroxydopamine mouse model of parkinsonism. We further submitted 6-hydroxydopamine-lesioned mice to chronic treatment with levodopa and evaluated the effects of tapentadol during levodopa OFF states and on levodopa-induced dyskinesia. Importantly, we found that tapentadol halted the aggravation of dyskinesia and improved the motor impairments during levodopa OFF states. Altogether, our findings raise the hypothesis that concomitant modulation of µ-opioid receptor and norepinephrine transporter might constitute relevant intervention strategies in PD and that tapentadol holds therapeutic potential that may be translated into the clinical practice.

Metallosis: A New Form of Autoimmune/Autoinflammatory Syndrome Induced by Adjuvants Syndrome (ASIA)?

Autoimmune/autoinflammatory syndrome induced by adjuvants (ASIA) is a new entity in which exposure to an adjuvant triggers an aberrant autoimmune response. Metallosis is a rare condition characterized by the deposition and build-up of metal debris in the soft tissues of the body associated with metal-on-metal (MOM) prosthetic devices. It can present with local/systemic symptoms and signs due to a chronic inflammatory host response. The authors present the case of a 51-year-old woman with a 6-month history of systemic complaints due to intoxication with metal ions from hip metallosis. This case highlights the importance of follow-up and continuous monitoring of patients with a hip prosthesis. As this is a rare condition, a patient presenting with unspecific symptoms such as ASIA syndrome induced by metallosis requires a high level of clinical suspicion as the removal of the adjuvant can resolve the condition. LEARNING POINTS: Asia syndrome is a new entity in which exposure to an adjuvant triggers an aberrant autoimmune response.Metallosis is an uncommon condition with local and systemic presentation.A high level of suspicion and close monitoring is needed in patients with vague systemic complaints.

Zebrafish as an Animal Model for Drug Discovery in Parkinson's Disease and Other Movement Disorders: A Systematic Review.

Movement disorders can be primarily divided into hypokinetic and hyperkinetic. Most of the hypokinetic syndromes are associated with the neurodegenerative disorder Parkinson's disease (PD). By contrast, hyperkinetic syndromes encompass a broader array of diseases, including dystonia, essential tremor, or Huntington's disease. The discovery of effective therapies for these disorders has been challenging and has also involved the development and characterization of accurate animal models for the screening of new drugs. Zebrafish constitutes an alternative vertebrate model for the study of movement disorders. The neuronal circuitries involved in movement in zebrafish are well characterized, and most of the associated molecular mechanisms are highly conserved. Particularly, zebrafish models of PD have contributed to a better understanding of the role of several genes implicated in the disease. Furthermore, zebrafish is a vertebrate model particularly suited for large-scale drug screenings. The relatively small size of zebrafish, optical transparency, and lifecycle, are key characteristics that facilitate the study of multiple compounds at the same time. Several transgenic, knockdown, and mutant zebrafish lines have been generated and characterized. Therefore, it is central to critically analyze these zebrafish lines and understand their suitability as models of movement disorders. Here, we revise the pathogenic mechanisms, phenotypes, and responsiveness to pharmacotherapies of zebrafish lines of the most common movement disorders. A systematic review of the literature was conducted by including all studies reporting the characterization of zebrafish models of the movement disorders selected from five bibliographic databases. A total of 63 studies were analyzed, and the most relevant data within the scope of this review were gathered. The majority (62%) of the studies were focused in the characterization of zebrafish models of PD. Overall, the zebrafish models included display conserved biochemical and neurobehavioral features of the phenomenology in humans. Nevertheless, in light of what is known for all animal models available, the use of zebrafish as a model for drug discovery requires further optimization. Future technological developments alongside with a deeper understanding of the molecular bases of these disorders should enable the development of novel zebrafish lines that can prove useful for drug discovery for movement disorders.

IgG4-related disease presenting with an epidural inflammatory pseudotumor: a case report.

BACKGROUND: Inflammatory pseudotumor is a rare clinical condition that can be related to immunoglobulin G4 disease. Only a few cases of spinal inflammatory pseudotumors have been reported in the literature and an association with immunoglobulin G4 disease was not conclusive in any of them. We describe what we believe to be the first biopsy-proven case of an epidural inflammatory pseudotumor related to immunoglobulin G4 disease. CASE PRESENTATION: A 57-year-old Caucasian woman presented to our hospital with severe paraparesis, gait disturbance, and sensory loss secondary to a relapsing epidural mass. Examination of a biopsy specimen revealed a lymphoplasmacytic infiltration with fibrosis and an immunoglobulin G4-positive plasma cell ratio of over 50 %, which are compatible with a diagnosis of immunoglobulin G4-related inflammatory pseudotumor. Our patient was successfully treated with systemic and epidural administration of glucocorticoids. CONCLUSION: Immunoglobulin G4-related disease is an emerging clinical condition in which central nervous system involvement is still uncommon. We describe the case of a patient with an epidural mass with medullar compression, which was proved to be an immunoglobulin G4-related epidural inflammatory pseudotumor. Our findings suggest a new manifestation of immunoglobulin G4-related disease. This disorder should be considered in the differential diagnosis of spinal tumors as a potentially treatable condition with glucocorticoids.

Synaptic Failure: Focus in an Integrative View of ALS.

From early description by Charcot, the classification of the Amyotrophic Lateral Sclerosis (ALS) is evolving from a subtype of Motor Neuron (MN) Disease to be considered rather a multi-systemic, non-cell autonomous and complex neurodegenerative disease. In the last decade, the huge amount of knowledge acquired has shed new insights on the pathological mechanisms underlying ALS from different perspectives. However, a whole vision on the multiple dysfunctional pathways is needed with the inclusion of information often excluded in other published revisions. We propose an integrative view of ALS pathology, although centered on the synaptic failure as a converging and crucial player to the etiology of the disease. Homeostasis of input and output synaptic activity of MNs has been proved to be severely and early disrupted and to definitively contribute to microcircuitry alterations at the spinal cord. Several cells play roles in synaptic communication across the MNs network system such as interneurons, astrocytes, microglia, Schwann and skeletal muscle cells. Microglia are described as highly dynamic surveying cells of the nervous system but also as determinant contributors to the synaptic plasticity linked to neuronal activity. Several signaling axis such as TNFα/TNFR1 and CX3CR1/CX3CL1 that characterize MN-microglia cross talk contribute to synaptic scaling and maintenance, have been found altered in ALS. The presence of dystrophic and atypical microglia in late stages of ALS, with a decline in their dynamic motility and phagocytic ability, together with less synaptic and neuronal contacts disrupts the MN-microglia dialogue, decreases homeostatic regulation of neuronal activity, perturbs "on/off" signals and accelerates disease progression associated to impaired synaptic function and regeneration. Other hotspot in the ALS affected network system is the unstable neuromuscular junction (NMJ) leading to distal axonal degeneration. Reduced neuromuscular spontaneous synaptic activity in ALS mice models was also suggested to account for the selective vulnerability of MNs and decreased regenerative capability. Synaptic destabilization may as well derive from increased release of molecules by muscle cells (e.g. NogoA) and by terminal Schwann cells (e.g. semaphorin 3A) conceivably causing nerve terminal retraction and denervation, as well as inhibition of re-connection to muscle fibers. Indeed, we have overviewed the alterations on the metabolic pathways and self-regenerative capacity presented in skeletal muscle cells that contribute to muscle wasting in ALS. Finally, a detailed footpath of pathologic changes on MNs and associated dysfunctional and synaptic alterations is provided. The oriented motivation in future ALS studies as outlined in the present article will help in fruitful novel achievements on the mechanisms involved and in developing more target-driven therapies that will bring new hope in halting or delaying disease progression in ALS patients.