DISPEL: A Python Framework for Developing Measures From Digital Health Technologies.

Goal: This paper introduces DISPEL, a Python framework to facilitate development of sensor-derived measures (SDMs) from data collected with digital health technologies in the context of therapeutic development for neurodegenerative diseases. Methods: Modularity, integrability and flexibility were achieved adopting an object-oriented architecture for data modelling and SDM extraction, which also allowed standardizing SDM generation, naming, storage, and documentation. Additionally, a functionality was designed to implement systematic flagging of missing data and unexpected user behaviors, both frequent in unsupervised monitoring. Results: DISPEL is available under MIT license. It already supports formats from different data providers and allows traceable end-to-end processing from raw data collected with wearables and smartphones to structured SDM datasets. Novel and literature-based signal processing approaches currently allow to extract SDMs from 16 structured tests (including six questionnaires), assessing overall disability and quality of life, and measuring performance outcomes of cognition, manual dexterity, and mobility. Conclusion: DISPEL supports SDM development for clinical trials by providing a production-grade Python framework and a large set of already implemented SDMs. While the framework has already been refined based on clinical trials' data, ad-hoc validation of the provided algorithms in their specific context of use is recommended to the users.

Natalizumab induces a rapid improvement of disability status and ambulation after failure of previous therapy in relapsing-remitting multiple sclerosis.

BACKGROUND: Natalizumab (Tysabri) is a monoclonal antibody that was recently approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). Our primary objective was to analyse the efficacy of natalizumab on disability status and ambulation after switching patients with RRMS from other disease-modifying treatments (DMTs). METHODS: A retrospective, observational study was carried out. All patients (n=45) initiated natalizumab after experiencing at least 1 relapse in the previous year under interferon-beta (IFNB) or glatiramer acetate (GA) treatments. The patients also had at least 1 gadolinium-enhancing (Gd+) lesion on their baseline brain MRI. Expanded Disability Status Scale (EDSS) scores, and performance on the Timed 25-Foot Walk Test and on the Timed 100-Metre Walk Test were prospectively collected every 4 weeks during 44 weeks of natalizumab treatment. Brain MRI scans were performed after 20 and 44 weeks of treatment. RESULTS: Sixty-two per cent of patients showed no clinical and no radiological signs of disease activity, and 29% showed a rapid and confirmed EDSS improvement over 44 weeks of natalizumab therapy. Patients with improvement on the EDSS showed similar levels of baseline EDSS and active T1 lesions, but had a significantly higher number of relapses, and 92% of them had experienced relapse-mediated sustained EDSS worsening in the previous year. A clinically meaningful improvement in ambulation speed was observed in approximately 30% of patients. CONCLUSIONS: These results indicate that natalizumab silences disease activity and rapidly improves disability status and walking performance, possibly through delayed relapse recovery in patients with RRMS who had shown a high level of disease activity under other DMTs.

Could visual neglect induce amblyopia?

Oculomotor nerve disease is a common cause of diplopia. When strabismus is present, absence of diplopia has to induce the research of either uncovering of visual fields or monocular suppression, amblyopia or blindness. We describe the case of a 41-year-old woman presenting with right oculomotor paresis and left object-centred visual neglect due to a right fronto-parietal haemorrhage expanding to the right peri-mesencephalic cisterna caused by the rupture of a right middle cerebral artery aneurysm. She never complained of diplopia despite binocular vision and progressive recovery of strabismus, excluding uncovering of visual fields. Since all other causes were excluded in this case, we hypothesise that the absence of diplopia was due to the object-centred visual neglect. Partial internal right oculomotor paresis causes an ocular deviation in abduction; the image being perceived deviated contralaterally to the left. Thus, in our case, the neglect of the left image is equivalent to a right monocular functional blindness. However, bell cancellation test clearly worsened when assessed in left monocular vision confirming that eye patching can worsen attentional visual neglect. In conclusion, our case argues for the possibility of a functional monocular blindness induced by visual neglect. We think that in presence of strabismus, absence of diplopia should induce the search for hemispatial visual neglect when supratentorial lesions are suspected.

Antiphospholipid antibodies and ischemic neuropathy following cardiac surgery.

Sciatic nerve palsy is an uncommon complication of cardiac surgery and is thought to be induced by a combination of reduced femoral artery blood flow, small vessel vascular disease or prolonged hypoxia. We here describe a new case which is the first described with transient elevation of antiphospholipid antibodies. Although transient elevation of lupus coagulation inhibitor is known to occur frequently in patients treated in an intensive care unit, there are very few data about the possible role of antiphospholipid antibodies in the generation of ischemic neuropathies. We can not prove that the ischemic neuropathy in our case has been favored by the presence of lupus coagulation inhibitor and antiphospholipid antibodies as the occurrence of the symptoms seemed to precede the transient elevation of lupus coagulation inhibitor. This case suggests that antiphospholipid antibodies and lupus coagulation inhibitor should be included in the work up of patients who present nerve damage after cardiac surgery but further studies are needed to ascertain this association.

The cerebellum may be directly involved in cognitive functions.

Neuropsychological deficits may occur in infratentorial strokes. Only minor cognitive disturbances are reported in unilateral anterior cerebellar lesions. Here, the authors describe a patient with bilateral anterior ponto-cerebellar ischemic lesions associated with major neuropsychological deficits. Cerebral PET and SPECT demonstrated no metabolic defect in supratentorial areas.

[Anti-tumor immunotherapy based on dendritic cells]. / L'immunothérapie anti-tumorale à base de cellules dendritiques.

In cancer immunotherapy, the use of dendritic cells (DC) loaded with tumor-associated antigens (TAA) emerged as a promising strategy. We initiated 3 pilot clinical trials with immunological endpoints using TAA loaded autologous DC. These trials showed that this approach was safe and associated with the induction of potent TAA specific IFN-gamma responses, which were transient despite the providing a further help through KLH presentation. Subcutaneous (s.c.) IL-2 administration was associated with long-lasting TAA specific IL-5 production. Clinical responses were observed in about 1/3 of the patients. Further improvements will take advantage of the use of a new type of DC cells (IL-3/IFN-beta DC) and of tumor cell-DC hybrids.

Human monocyte-derived dendritic cells produce bioactive gelatinase B: inhibition by IFN-beta.

We studied the secretion of gelatinase B by dendritic cells (DC) generated by culturing human peripheral blood monocytes in granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). First, we found the intracellular expression of gelatinase B on sections of fixed DC pellets. Zymography analysis of the supernatants of DC cultured for 72 h demonstrated the presence of gelatinase B. To determine if DC produce net enzymatic activity, bioactive gelatinase, a novel sensitive fluorescent-activated substrate conversion (FASC) assay was used to complement the zymography data. Culture media of unstimulated DC demonstrated reproducible net gelatinolytic activity. Tumor necrosis factor-alpha (TNF-alpha) IL-1beta but not lipopolysaccharide (LPS) stimulation caused a significant increase in gelatinase B production in zymography analysis. Both types of stimulation failed to increase net gelatinase activity in FASC assay. Interestingly, interferon-beta (IFN-beta) significantly diminished both the total zymolytic production and the net bioactive gelatinase produced by DC in a dose-dependent manner. We conclude that human monocyte-derived DC secrete bioactive gelatinase B and that IFN-beta inhibits this production.

IFN-beta interferes with the differentiation of dendritic cells from peripheral blood mononuclear cells: selective inhibition of CD40-dependent interleukin-12 secretion.

We studied the effects of interferon-beta (IFN-beta) on the differentiation of dendritic cells (DC) obtained by culturing plastic-adherent peripheral blood mononuclear cells (PBMC) from a total of 30 healthy volunteers in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). First, we found that the addition of IFN-beta at the initiation of the culture did not modify DC morphology but caused a reproducible and statistically significant upregulation of HLA-DR, CD86, and CD80 surface expression. CD1a expression was significantly reduced, and CD40 expression was unchanged. We then determined the influence of IFN-beta on the production of cytokines by DC. DC differentiated in the presence of IFN-beta secreted significantly less IL-12 (p40 and p70) both spontaneously and on activation by fibroblasts transfected with the CD40L gene. This effect of IFN-beta was dose dependent and selective, as it was not observed for IL-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha). As a consequence, DC differentiated in the presence of IFN-beta induced significantly less IFN-gamma secretion by alloreactive T cells, whereas they were more efficient than control DC in eliciting IL-5 secretion. We conclude that the direct action of IFN-beta on DC causes inhibition of their ability to secrete IL-12 in response to CD40 ligation and to elicit Th1 type responses.

Interferon-beta inhibits Th1 responses at the dendritic cell level. Relevance to multiple sclerosis.

Clinical studies have demonstrated beneficial effects of interferon-beta (IFN-beta) therapy in multiple sclerosis (MS) patients. However, the mechanism of action of IFN-beta in MS remains unknown. IFN-beta has even been demonstrated to enhance isolated T cell secretion of IFN-gamma, a cytokine proven to be deleterious in MS. However, IFN-beta inhibits IFN-gamma secretion of T cells, when they are stimulated by antigen presenting cells (APC). We therefore decided to study the effects of IFN-beta on the in vitro differentiation of dendritic cells (DC), a major class of APC. First, we found that the addition of IFN-beta at the initiation of the differentiation did not modify DC morphology, but enhanced the expression of molecules involved in antigen presentation (HLA-DR, B7/1 and B7/2). However, DC, differentiated in the presence of IFN-beta, secreted less interleukin-12 (IL-12) both spontaneously and upon activation by CD40-ligand bearing cells. As a consequence, DC differentiated in the presence of IFN-beta induced less IFN-gamma secretion by alloreactive T cells. We conclude that the direct action of IFN-beta on DC results in inhibition of their ability to secrete IL-12 and to elicit Thelper-1 (Th-1) type responses. These results are of particular interest in MS, in which a critical role for IL-12 has recently been suggested by a number of clinical and experimental observations.

The idiopathic hypereosinophilic syndrome: clinical presentation, pathogenesis and therapeutic strategies.

The idiopathic hypereosinophilic syndrome (HES) is a heterogenous disease entity characterized by persistent unexplained hypereosinophilia generally complicated by end-organ damage. Correct diagnosis and management are important in order to prevent long-term complications. Furthermore, it appears that HES represents a premalignant state in some patients, and close follow-up is necessary to detect early signs of malignant transformation. Previous studies of patient cohorts have led to the identification of a subgroup of patients with various clinical and biological features of primitive myeloproliferative disease. Patients in this subgroup have a clinically more aggressive disease in terms of organ damage and eventually develop acute myeloid leukemia. Among the remaining patients, it appears that some present an underlying T-cell disorder characterized by overproduction of Th2-type cytokines in vivo. Indeed, lymphocytes belonging to the Th2 subset are implicated in the maturation, activation and recruitment of eosinophils, essentially through the production of IL-5. Such patients appear to present a more benign disease at short term; however, they may develop T-cell lymphoma years after initial diagnosis. Therapy of HES includes glucocorticoids, hydroxyurea and more recently, interferon-alpha. Prednisone is generally recommended initially, followed by hydroxyurea in case of treatment failure. Until now, interferon-alpha has been reserved for refractory cases of HES. Our proposal for a new treatment strategy, based on current understanding of the pathogenesis of different subgroups of HES and on the mechanisms of action of the proposed therapeutic agents, which will be discussed in detail. Moreover, prevention of malignant transformation has become a new subject of concern when considering the beneficial effects of drugs.

Analysis of ballistic movements in ataxic hemiparesis following a pontine stroke.

Although cerebellar-like ataxia is a well known component of the ataxic hemiparesis (AH), the mechanism of hypermetria in AH has not been established. We describe a patient presenting a left AH following a right pontine infarction. We investigated the ballistic flexion movements of both wrists and the associated agonist and antagonist electromyographic (EMG) activities, before and after addition of inertial loads. At the time of motion analysis, neurological examination showed cerebellar-like dysmetria of the left side but the patient had recovered a normal strength. In the basal state (without addition of loads), movements of the left wrist were hypermetric. The duration of the agonist EMG activity was prolonged and the onset latency of the antagonist EMG activity was not delayed. Moreover, when a mass was added, the hypermetria was unchanged because the patient was unable to adapt appropriately neither the agonist, nor the antagonist EMG activity. We suggest that the hypermetria was due to an imbalance between the duration of the agonist EMG activity (the launching force) and the duration of the antagonist EMG activity (the braking force).