32 research outputs found

    Anomalous Hypothalamic Responses to Humor in Cataplexy

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    Cataplexy is observed in a subset of patients with narcolepsy and affects approximately 1 in 2,000 persons. Cataplexy is most often triggered by strong emotions such as laughter, which can result in transient, yet debilitating, muscle atonia. The objective of this study was to examine the neural systems underlying humor processing in individuals with cataplexy.While undergoing functional Magnetic Resonance Imaging (fMRI), we showed ten narcolepsy-cataplexy patients and ten healthy controls humorous cartoons. In addition, we examined the brain activity of one subject while in a full-blown cataplectic attack. Behavioral results showed that participants with cataplexy rated significantly fewer humorous cartoons as funny compared to controls. Concurrent fMRI showed that patients, when compared to controls and in the absence of overt cataplexy symptoms, showed pronounced activity in the emotional network including the ventral striatum and hypothalamus while viewing humorous versus non-humorous cartoons. Increased activity was also observed in the right inferior frontal gyri--a core component of the inhibitory circuitry. In comparison, the one subject who experienced a cataplectic attack showed dramatic reductions in hypothalamic activity.These findings suggest an overdrive of the emotional circuitry and possible compensatory suppression by cortical inhibitory regions in cataplexy. Moreover, during cataplectic attacks, the hypothalamus is characterized by a marked decrease in activity similar to that observed during sleep. One possible explanation for these findings is an initial overdrive and compensatory shutdown of the hypothalamus resulting in full cataplectic symptoms

    Early over expression of messenger RNA for multiple genes, including insulin, in the Pancreatic Lymph Nodes of NOD mice is associated with Islet Autoimmunity

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    <p>Abstract</p> <p>Background</p> <p>Autoimmune diabetes (T1D) onset is preceded by a long inflammatory process directed against the insulin-secreting β cells of the pancreas. Deciphering the early autoimmune mechanisms represents a challenge due to the absence of clinical signs at early disease stages. The aim of this study was to identify genes implicated in the early steps of the autoimmune process, prior to inflammation, in T1D. We have previously established that insulin autoantibodies (E-IAA) predict early diabetes onset delineating an early phenotypic check point (window 1) in disease pathogenesis. We used this sub-phenotype and applied differential gene expression analysis in the pancreatic lymph nodes (PLN) of 5 weeks old Non Obese Diabetic (NOD) mice differing solely upon the presence or absence of E-IAA. Analysis of gene expression profiles has the potential to provide a global understanding of the disease and to generate novel hypothesis concerning the initiation of the autoimmune process.</p> <p>Methods</p> <p>Animals have been screened weekly for the presence of E-IAA between 3 and 5 weeks of age. E-IAA positive or negative NOD mice at least twice were selected and RNAs isolated from the PLN were used for microarray analysis. Comparison of transcriptional profiles between positive and negative animals and functional annotations of the resulting differentially expressed genes, using software together with manual literature data mining, have been performed.</p> <p>Results</p> <p>The expression of 165 genes was modulated between E-IAA positive and negative PLN. In particular, genes coding for insulin and for proteins known to be implicated in tissue remodelling and Th1 immunity have been found to be highly differentially expressed. Forty one genes showed over 5 fold differences between the two sets of samples and 30 code for extracellular proteins. This class of proteins represents potential diagnostic markers and drug targets for T1D.</p> <p>Conclusion</p> <p>Our data strongly suggest that the immune related mechanisms taking place at this early age in the PLN, correlate with homeostatic changes influencing tissue integrity of the adjacent pancreatic tissue. Functional analysis of the identified genes suggested that similar mechanisms might be operating during pre-inflammatory processes deployed in tissues i) hosting parasitic microorganisms and ii) experiencing unrestricted invasion by tumour cells.</p

    Methods of probing the interactions between small molecules and disordered proteins

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    It is generally recognized that a large fraction of the human proteome is made up of proteins that remain disordered in their native states. Despite the fact that such proteins play key biological roles and are involved in many major human diseases, they still represent challenging targets for drug discovery. A major bottleneck for the identification of compounds capable of interacting with these proteins and modulating their disease-promoting behaviour is the development of effective techniques to probe such interactions. The difficulties in carrying out binding measurements have resulted in a poor understanding of the mechanisms underlying these interactions. In order to facilitate further methodological advances, here we review the most commonly used techniques to probe three types of interactions involving small molecules: (1) those that disrupt functional interactions between disordered proteins; (2) those that inhibit the aberrant aggregation of disordered proteins, and (3) those that lead to binding disordered proteins in their monomeric states. In discussing these techniques, we also point out directions for future developments.Gabriella T. Heller is supported by the Gates Cambridge Trust Scholarship. Francesco A. Aprile is supported by a Senior Research Fellowship award from the Alzheimer’s Society, UK (grant number 317, AS-SF-16-003)

    Methods of probing the interactions between small molecules and disordered proteins

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    Pediatric multiple sclerosis: analysis of clinical and epidemiological aspects according to National MS Society Consensus 2007 Esclerose múltipla pediátrica: análise de aspectos clínicos e epidemiológicos de acordo com o Consenso de 2007 da Sociedade Americana de Esclerose Múltipla

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    OBJECTIVE: To describe the epidemiological and clinical characteristics of child/adolescence multiple sclerosis (MS). METHOD: According to a descriptive, cohort study, with comparison of groups, data of 31 cases of child/adolescent MS, diagnosed at State Reference Center for Demyelinating Diseases - Hospital da Restauração, Recife, Pernambuco, Brazil, from 1987 to July 2007, were analyzed. The variables were: sex, initial symptoms, time for diagnosis, time of disease onset (early childhood, later childhood and adolescence), time of follow-up, number of relapses, relapses index and disability. Using SPSS software, version 13.0, t Student and Mann-Whitney tests were performed, with significance level of 0.05. RESULTS: There were 3 (9.7%) cases of early childhood MS, 9 (29%), of late childhood MS, and 19 (61.3%), of adolescence MS. The general sex rate female: male was 1.8:1, varying according to age of onset. The predominant deficits were motor (12; 38.7%) and brainstem/cerebellum (7; 22.5%) especially on subsequent relapses of relapsing/remitting form. Time for diagnosis and average relapses index were higher in early childhood than in adolescence class (p=0.049 and p=0.028, respectively). Disability was higher for primary and secondary MS, as well as for early childhood. CONCLUSION: Early childhood MS presents proper and different characteristics from adults, consisting in a difficult diagnosis that demands aid of expert neurologist on MS.<br>OBJETIVO: Descrever características epidemiológicas e clínicas de casos de esclerose múltipla (EM) de início precoce. MÉTODO: Em estudo descritivo, prospectivo, tipo coorte, com comparação de grupos, foram analisados 31 portadores de EM de início precoce, diagnosticados no Centro Estadual de Referência para Atenção a Pacientes Portadores de Doenças Desmielinizantes do Hospital da Restauração, Recife, Pernambuco, entre 1987 e julho de 2007. As classes ao primeiro surto foram: infantil precoce, infantil tardia e juvenil, e as variáveis: sexo; sintomas iniciais; tempo para diagnóstico, de doença e de seguimento; número de surtos, índice de recidivas e EDSS. Com o programa SPSS, versão 13.0, foram utilizados os testes t de Student e Mann-Whitney com nível de significância de 0,05. RESULTADOS: Foram observados 3 (9,7%) casos de EM infantil precoce, 9 (29%), infantil tardia, e 19 (61,3%), juvenil. A razão geral de sexo feminino:masculino igualou-se a 1,8:1, variando segundo idade de início. Predominou comprometimento motor (12; 38,7%) e de tronco encefálico ou cerebelo (7; 22,5%), especialmente nos surtos subseqüentes da forma surto-remissão. O tempo para diagnóstico e o índice médio de recidivas foram maiores na infantil precoce que na juvenil (p=0,049 e p=0,028, respectivamente. O grau de incapacidade foi maior nas formas primária e secundária progressiva, assim como na infantil precoce. CONCLUSÃO: A EM na infância e adolescência apresenta características próprias, diferentes daquelas do adulto, constituindo-se em diagnóstico difícil, que exige auxílio de especialista em EM

    Brain leukocyte infiltration initiated by peripheral inflammation or experimental autoimmune encephalomyelitis occurs through pathways connected to the CSF-filled compartments of the forebrain and midbrain.

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    International audienceUNLABELLED: ABSTRACT: BACKGROUND: Cerebrospinal fluid (CSF) has been considered as a preferential pathway of circulation for immune cells during neuroimmune surveillance. In order to evaluate the involvement of CSF-filled spaces in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis, we performed a time-course analysis of immune cell association with the CSF-containing ventricles, velae, and cisterns in two active models of this disease. METHODS: Guinea-pig spinal cord homogenate-induced EAE in rat and myelin oligodendrocyte glycoprotein-induced EAE in mouse were used. Leukocyte distribution and phenotypes were investigated by immunohistochemistry in serial sections of brain areas of interest, as well as in CSF withdrawn from rat. Immune cells associated with the choroid plexuses were quantified. RESULTS: Freund's adjuvant-induced peripheral inflammation in the absence of brain antigen led to a subtle but definite increase in the number of myeloid cells in the extraventricular CSF spaces. In both rats and mice, EAE was characterized by a sustained and initial infiltration of lymphocytes and monocytes within forebrain/midbrain fluid-filled compartments such as the velum interpositum and ambient cisterns, and certain basal cisterns. Leukocytes further infiltrated periventricular and pericisternal parenchymal areas, along perivascular spaces or following a downward CSF-to-tissue gradient. Cells quantified in CSF sampled from rats included lymphocytes and neutrophils. The distinctive pattern of cell distribution suggests that both the choroid plexus and the vessels lying in the velae and cisterns are gates for early leukocyte entry in the central nervous system. B-cell infiltration observed in the mouse model was restricted to CSF-filled extraventricular compartments. CONCLUSION: These results identified distinctive velae and cisterns of the forebrain and midbrain as preferential sites of immune cell homing following peripheral and early central inflammation and point to a role of CSF in directing brain invasion by immune cells during EAE
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