Inhibiting the inflammasome with MCC950 counteracts muscle pyroptosis and improves Duchenne muscular dystrophy.

Background: Duchenne muscular dystrophy (DMD) is the most common inherited human myopathy. Typically, the secondary process involving severe inflammation and necrosis exacerbate disease progression. Previously, we reported that the NLRP3 inflammasome complex plays a crucial role in this disorder. Moreover, pyroptosis, a form of programmed necrotic cell death, is triggered by NLRP3 via gasdermin D (GSDMD). So far, pyroptosis has never been described either in healthy muscle or in dystrophic muscle. The aim of this study was to unravel the role of NLRP3 inflammasome in DMD and explore a potentially promising treatment with MCC950 that selectively inhibits NLRP3. Methods: Four-week-old mdx mice (n=6 per group) were orally treated for 2 months with MCC950 (mdx-T), a highly potent, specific, small-molecule inhibitor of NLRP3, and compared with untreated (mdx) and wild-type (WT) mice. In vivo functional tests were carried out to measure the global force and endurance of mice. Ex vivo biochemical and molecular analyses were performed to evaluate the pathophysiology of the skeletal muscle. Finally, in vitro tests were conducted on primary cultures of DMD human myotubes. Results: After MCC950 treatment, mdx mice exhibited a significant reduction of inflammation, macrophage infiltration and oxidative stress (-20 to -65%, P<0.05 vs untreated mdx). Mdx-T mice displayed considerably less myonecrosis (-54%, P<0.05 vs mdx) and fibrosis (-75%, P<0.01 vs mdx). Moreover, a more mature myofibre phenotype, characterized by larger-sized fibres and higher expression of mature myosin heavy chains 1 and 7 was observed. Mdx-T also exhibited enhanced force and resistance to fatigue (+20 to 60%, P<0.05 or less). These beneficial effects resulted from MCC950 inhibition of both active caspase-1 (-46%, P=0.075) and cleaved gasdermin D (N-GSDMD) (-42% in medium-sized-fibres, P<0.001). Finally, the anti-inflammatory action and the anti-pyroptotic effect of MCC950 were also recapitulated in DMD human myotubes. Conclusion: Specific inhibition of the NLRP3 inflammasome can significantly attenuate the dystrophic phenotype. A novel finding of this study is the overactivation of GSDMD, which is hampered by MCC950. This ultimately leads to less inflammation and pyroptosis and to a better muscle maturation and function. Targeting NLRP3 might lead to an effective therapeutic approach for a better management of DMD.

Single-longitudinal-mode pumped pulsed-dye amplifier for high-resolution laser spectroscopy.

The In-Gas-jet Laser Ionization and Spectroscopy (IGLIS) technique relies on narrow-bandwidth, high-peak-power, short-pulse-length (≈10 ns), and high-repetition-rate laser pulses to probe, precisely and efficiently, the hyperfine structure of medium-heavy and heavy isotopes, embedded in a supersonic jet. The power and repetition rate requirements of the laser system are met by combining ≈100 W, 8 ns pulse width, 10 kHz commercial Nd:YAG pump lasers with a single-mode continuous wave seeded Pulsed Dye Amplifier (PDA). The common multi-longitudinal-mode operation of these Nd:YAG pump lasers causes, however, undesirable frequency sidebands in the output spectrum of the PDA system, hindering the attainable spectral resolution, a correct interpretation, and an accurate analysis of the hyperfine spectra. In this article, a new prototype Nd:YAG laser is presented, which combined with the PDA system is capable of providing quasi-transform-limited laser pulses at 10 kHz, with only limited losses in laser power. This system reduces any spectral sideband amplitude below a proven upper limit of 0.2% with one order of magnitude extra reduction expected based on simulations. A full characterization of both the Nd:YAG and PDA laser systems is done by studying the temporal and frequency behavior in detail. This study is finalized by a performance benchmark of this combined laser system in the hyperfine spectroscopy of copper isotopes, showcasing its applicability for future IGLIS studies.

Late-onset Pompe disease (LOPD) in Belgium: clinical characteristics and outcome measures.

BACKGROUND: Late-onset Pompe disease (LOPD) is a rare, hereditary, progressive disorder that is usually characterized by limb-girdle muscle weakness and/or respiratory insufficiency. LOPD is caused by mutations in the acid alpha-glucosidase (GAA) gene and treated with enzyme replacement therapy (ERT). METHODS: We studied the clinical, brain imaging, and genetic features of the Belgian cohort of late-onset Pompe disease patients (N = 52), and explored the sensitivity of different outcome measures, during a longitudinal period of 7 years (2010-2017), including the activity limitations ActivLim score, 6 min walking distance (6MWD), 10 m walk test (10MWT), MRC sum score, and forced vital capacity (FVC) sitting/supine. RESULTS: In Belgium, we calculated an LOPD prevalence of 3.9 per million. Mean age at onset of 52 LOPD patients was 28.9 years (SD: 15.8 y), ranging from 7 months to 68 years. Seventy-five percent (N = 39) of the patients initially presented with limb-girdle weakness, whereas in 13% (N = 7) respiratory symptoms were the only initial symptom. Non-invasive ventilation (NIV) was started in 37% (N = 19), at a mean age of 49.5 years (SD: 11.9 y), with a mean duration of 15 years (SD: 10.2 y) after symptom onset. Brain imaging revealed abnormalities in 25% (N = 8) of the patients, with the presence of small cerebral aneurysm(s) in two patients and a vertebrobasilar dolichoectasia in another two. Mean diagnostic delay was 12.9 years. All patients were compound heterozygotes with the most prevalent mutation being c.-32-13 T > G in 96%. We identified two novel mutations in GAA: c.1610_1611delA and c.186dup11. For the 6MWD, MRC sum score, FVC sitting and FVC supine, we measured a significant decrease over time (p = 0.0002, p = 0.0001, p = 0.0077, p = 0.0151), which was not revealed with the ActivLim score and 10MWT (p > 0.05). CONCLUSIONS: Awareness on LOPD should even be further increased because of the long diagnostic delay. The 6MWD, but not the ActivLim score, is a sensitive outcome measure to follow up LOPD patients.

Serial electrophysiology in Guillain-Barré syndrome: A retrospective cohort and case-by-case multicentre analysis.

OBJECTIVES: To assess the usefulness of serial electrophysiology in Guillain-Barré syndrome (GBS) in a multicenter setting and the reasons for change in electrodiagnostic subtypes with serial studies. METHODS: We retrospectively analysed serial electrophysiology of 51 patients with GBS from 4 European centres. Proportions of subtypes were determined at each timing. Individual case analyses were also performed where diagnostic changes occurred with either criteria, to ascertain if changes were due to disease progression or criteria inadequacy. RESULTS: At first study, comparing old vs new criteria, acute inflammatory demyelinating polyneuropathy (AIDP) was diagnosed in 70.6% vs 51%, axonal GBS in 15.7% vs 39.2%, equivocal forms in 11.8% vs 7.8%. At second study, AIDP was diagnosed in 72.5% vs 52.9%, axonal GBS in 9.8% vs 33.3%, equivocal forms in 15.7% vs 11.7%. Subtype proportions were unchanged, indicating serial studies did not, in the cohort, alter diagnostic rates for each subtype irrespective of criteria used. Individual review of cases where subtype electrodiagnosis changed indicated suboptimal specificity for AIDP/sensitivity for axonal GBS as main cause of diagnostic shifts with old criteria, whereas disease progression explained most changes with new criteria (55.6% vs 81.8%; P = .039). CONCLUSIONS: Serial electrophysiology is unhelpful in GBS. Repeat studies cannot represent the gold standard as electrodiagnosis may alter due to disease progression. Changes in electrodiagnosis relate more often to disease progression with new criteria but are more frequently due to suboptimal sensitivity/specificity with old criteria. A single electrophysiological study using the most accurate available criteria appears sufficient in GBS.

A homozygous DPM3 mutation in a patient with alpha-dystroglycan-related limb girdle muscular dystrophy.

Defects of O-linked glycosylation of alpha-dystroglycan cause a wide spectrum of muscular dystrophies ranging from severe congenital muscular dystrophy associated with abnormal brain and eye development to mild limb girdle muscular dystrophy. We report a female patient who developed isolated pelvic girdle muscle weakness and wasting, which became symptomatic at age 42. Exome sequencing uncovered a homozygous c.131T > G (p.Leu44Pro) substitution in DPM3, encoding dolichol-P-mannose (DPM) synthase subunit 3, leading to a 50% reduction of enzymatic activity. Decreased availability of DPM as an essential donor substrate for protein O-mannosyltransferase (POMT) 1 and 2 explains defective skeletal muscle alpha-dystroglycan O-glycosylation. Our findings show that DPM3 mutations may lead to an isolated and mild limb girdle muscular dystrophy phenotype without cardiomyopathy.

European consensus for starting and stopping enzyme replacement therapy in adult patients with Pompe disease: a 10-year experience.

BACKGROUND AND PURPOSE: Pompe disease is a rare inheritable muscle disorder for which enzyme replacement therapy (ERT) has been available since 2006. Uniform criteria for starting and stopping ERT in adult patients were developed and reported here. METHODS: Three consensus meetings were organized through the European Pompe Consortium, a network of experts from 11 European countries in the field of Pompe disease. A systematic review of the literature was undertaken to determine the effectiveness of ERT in adult patients on a range of clinical outcome measures and quality of life. A narrative synthesis is presented. RESULTS: Consensus was reached on how the diagnosis of Pompe disease should be confirmed, when treatment should be started, reasons for stopping treatment and the use of ERT during pregnancy. This was based on expert opinion and supported by the literature. One clinical trial and 43 observational studies, covering a total of 586 individual adult patients, provided evidence of a beneficial effect of ERT at group level. At individual patient level, the response to treatment varied, but factors associated with a patient's response to ERT were not described in many studies. Eleven observational studies focused on more severely affected patients, suggesting that ERT can also be beneficial in these patients. There are no studies on the effects of ERT in pre-symptomatic patients. CONCLUSIONS: This is the first European consensus recommendation for starting and stopping ERT in adult patients with Pompe disease, based on the extensive experience of experts from different countries.

Towards high-resolution laser ionization spectroscopy of the heaviest elements in supersonic gas jet expansion.

Resonant laser ionization and spectroscopy are widely used techniques at radioactive ion beam facilities to produce pure beams of exotic nuclei and measure the shape, size, spin and electromagnetic multipole moments of these nuclei. However, in such measurements it is difficult to combine a high efficiency with a high spectral resolution. Here we demonstrate the on-line application of atomic laser ionization spectroscopy in a supersonic gas jet, a technique suited for high-precision studies of the ground- and isomeric-state properties of nuclei located at the extremes of stability. The technique is characterized in a measurement on actinium isotopes around the N=126 neutron shell closure. A significant improvement in the spectral resolution by more than one order of magnitude is achieved in these experiments without loss in efficiency.

Laing early-onset distal myopathy in a Belgian family.

We report the first Belgian family with Laing early-onset distal myopathy (MPD1). The proposita started limping at age 7. Later, there was severe weakness of proximal and distal muscles, including neck flexors. Her daughter developed foot drop at age 4. Progressive weakness of distal limb extensor muscles and mild weakness of the neck flexor and proximal muscles were noted. In both patients, CK and nerve conductions were normal, but EMG showed a brief, small amplitude, abundant, polyphasic potential pattern. Heart and respiration were normal. Several muscle biopsies have been performed in each with various diagnoses, including aspecific myopathic changes, congenital fibre type disproportion, and denervation-reinnervation. Analysis of MYH7 revealed a c.4522_4524del mutation (p.Glu1508del). This appears to be a de novo mutation, which has been reported in French, Norwegian, and Finnish patients.

Two-step laser ionization schemes for in-gas laser ionization and spectroscopy of radioactive isotopes.

The in-gas laser ionization and spectroscopy technique has been developed at the Leuven isotope separator on-line facility for the production and in-source laser spectroscopy studies of short-lived radioactive isotopes. In this article, results from a study to identify efficient optical schemes for the two-step resonance laser ionization of 18 elements are presented.

Measurement of the first ionization potential of astatine by laser ionization spectroscopy.

The radioactive element astatine exists only in trace amounts in nature. Its properties can therefore only be explored by study of the minute quantities of artificially produced isotopes or by performing theoretical calculations. One of the most important properties influencing the chemical behaviour is the energy required to remove one electron from the valence shell, referred to as the ionization potential. Here we use laser spectroscopy to probe the optical spectrum of astatine near the ionization threshold. The observed series of Rydberg states enabled the first determination of the ionization potential of the astatine atom, 9.31751(8) eV. New ab initio calculations are performed to support the experimental result. The measured value serves as a benchmark for quantum chemistry calculations of the properties of astatine as well as for the theoretical prediction of the ionization potential of superheavy element 117, the heaviest homologue of astatine.

Mutations in SACS cause atypical and late-onset forms of ARSACS.

BACKGROUND: Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a complex neurodegenerative disorder caused by mutations in SACS. The phenotype consists of a childhood-onset triad of cerebellar ataxia, peripheral neuropathy, and pyramidal tract signs. OBJECTIVE: To provide more insight into the prevalence of SACS mutations and the variability of the associated phenotype. METHODS: Mutation screening of SACS by direct sequencing and multiplex amplicon quantification for detection of intragenic copy number variations in a cohort of 85 index patients with phenotypes suggestive for ARSACS. Additional short tandem repeat (STR) marker analysis was performed for haplotype sharing. RESULTS: In 11 families,18 new SACS mutations were found (12.9% of total cohort). Five patients displayed onset ages in adulthood, a feature not known to be associated with ARSACS. The remaining index patients displayed a classic early onset phenotype. Initial phenotypic presentation was atypical in several patients, obscuring the clinical diagnosis. A founder mutation in SACS was identified in 3 Belgian families. In one isolated patient, an intragenic SACS deletion of exons 3-5 was detected. Partial SACS deletions were not previously described. CONCLUSIONS: In this study, we enlarge the ARSACS phenotype and the underlying genetic spectrum of SACS mutations. Patients with ARSACS are more common than previously known and risk underdiagnosis due to late onset age and unusual presentation.

European Federation of Neurological Societies/Peripheral Nerve Society guideline on management of chronic inflammatory demyelinating polyradiculoneuropathy: report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society - first revision.

BACKGROUND: Consensus guidelines on the definition, investigation, and treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) have been previously published in European Journal of Neurology and Journal of the Peripheral Nervous System. OBJECTIVES: To revise these guidelines. METHODS: Disease experts, including a representative of patients, considered references retrieved from MEDLINE and Cochrane Systematic Reviews published between August 2004 and July 2009 and prepared statements that were agreed in an iterative fashion. RECOMMENDATIONS: The Task Force agreed on Good Practice Points to define clinical and electrophysiological diagnostic criteria for CIDP with or without concomitant diseases and investigations to be considered. The principal treatment recommendations were: (i) intravenous immunoglobulin (IVIg) (Recommendation Level A) or corticosteroids (Recommendation Level C) should be considered in sensory and motor CIDP; (ii) IVIg should be considered as the initial treatment in pure motor CIDP (Good Practice Point); (iii) if IVIg and corticosteroids are ineffective, plasma exchange (PE) should be considered (Recommendation Level A); (iv) if the response is inadequate or the maintenance doses of the initial treatment are high, combination treatments or adding an immunosuppressant or immunomodulatory drug should be considered (Good Practice Point); (v) symptomatic treatment and multidisciplinary management should be considered (Good Practice Point).

New type of asymmetric fission in proton-rich nuclei.

A very exotic process of ß-delayed fission of 180Tl is studied in detail by using resonant laser ionization with subsequent mass separation at ISOLDE (CERN). In contrast to common expectations, the fission-fragment mass distribution of the post-ß-decay daughter nucleus 180Hg (N/Z=1.25) is asymmetric. This asymmetry is more surprising since a mass-symmetric split of this extremely neutron-deficient nucleus would lead to two 90Zr fragments, with magic N=50 and semimagic Z=40. This is a new type of asymmetric fission, not caused by large shell effects related to fragment magic proton and neutron numbers, as observed in the actinide region. The newly measured branching ratio for ß-delayed fission of 180Tl is 3.6(7) × 10(-3)%, approximately 2 orders of magnitude larger than in an earlier study.

Physiologic variables for videofluoromanometric assessment of dysphagia: an exploratory study.

STUDY AIM: To assess the physiological variables among Upper Esophageal Sphincter Nadir (UESN), Hypopharyngeal Peak Pressure (HPP) and Pharyngo-Esophageal Pressure Gradient (PEPG) for Videofluoromanometry (VFM). PATIENTS & METHOD: Exploratory non-randomised prospective study comparing UESN, HPP and PEPG of three cohorts of individuals presumably presenting very distinctive "manometric signatures" based on McConnel's Piston Model of swallowing: 11 non-dysphagic volunteers called the Control Group (CG), 10 dysphagic patients presenting a Myotonic Dystrophy (MD), at various stages of evolution, and 10 patients presenting a CricoPharyngeal Barr (CPB), with no post-swallow pharyngeal residue at a previous Modified Barium Swallow (MBS). VFM tests are performed using solid-state three unidirectional transducers produced by Gaeltec Inc. The simultaneous display storage of the standard fluoroscopic swallow of 10 ml liquid barium with UESN and HPP measurements, continuously recorded on a 3-channel polygraph, is performed using a Kay-Pentax Swallowing Work Station. PEPG calculations are subsequently made. RESULTS: Significant different HPP and PEPG values were observed between the three cohorts. MD patients presented HPP and PEPG below 100 mmHg while CPB patients presented HPP and PEPG above 200 mmHg. The CG presented HPP and PEPG between 100 and 200 mmHg. UESN values revealed no significant difference between the three cohorts. A reading scale is proposed. The aim of the scale is to make a link between HPP or PEPG values and physiopathological (not diagnostic) conditions. Patients presenting an HPP or PEPG below 100 mmHg indicate a High probability of Pharyngeal Propulsion Impairment while patients presenting an HPP or PEPG above 200 mmHg are more likely to have an Increased Flow Resistance with appropriate Propulsion Response. Pros and cons for calculation of the PEPG, representing a possibly unnecessary step, are discussed. CONCLUSIONS: In our study, the use of HPP or PEPG as physiological variables provides quantitative data that allow VFM to discriminate three very distinctive swallowing conditions. Further studies are needed to assess the HPP and PEPG obtained with other manometic devices within the same specific populations for them to be considered as universal physiological variables. Eventually, further investigations should answer the question as to whether the calculation of the PEPG represents any value in comparison with HPP measurement alone.

Magnetic dipole moment of (57,59)Cu measured by in-gas-cell laser spectroscopy.

For the first time, in-gas-cell laser spectroscopy study of the (57,59,63,65)Cu isotopes has been performed using the 244.164 nm optical transition from the atomic ground state of copper. The nuclear magnetic dipole moments for (57,59,65)Cu relative to that of (63)Cu have been extracted. The new value for (57)Cu of mu((57)Cu) = +2.582(7)mu(N) is in strong disagreement with the previous literature value but in good agreement with recent theoretical and systematic predictions.

Validity of diagnostic criteria for chronic inflammatory demyelinating polyneuropathy: a multicentre European study.

BACKGROUND: Diagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP) have variable sensitivity and specificity. Newly published criteria by Koski et al combine clinical and electrophysiological components, either of which suffices to establish the diagnosis. European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria require mandatory electrophysiology, as do other sets of criteria. METHODS: The value of the two above-mentioned sets of criteria, on 151 patients with CIDP, and 162 controls with axonal neuropathy, from four European centres was assessed. Results were compared with Van den Bergh and Piéret's criteria and those of the American Academy of Neurology (AAN). The utility of more extensive nerve-conduction studies was ascertained. RESULTS: Koski et al's criteria had a sensitivity of 63% and specificity of 99.3%. With unilateral, right-sided, forearm/foreleg, four-nerve studies, EFNS/PNS criteria offered a sensitivity of 81.3% and specificity of 96.2% for "definite/probable" CIDP. Van den Bergh and Piéret's criteria had a sensitivity of 79.5% and specificity of 96.9%. AAN criteria were poorly sensitive (45.7%) but highly specific (100%). "Possible" electrophysiological CIDP as per EFNS/PNS criteria were poorly specific (69.2%). More extensive studies increased the diagnostic sensitivity of EFNS/PNS criteria (96.7%) but reduced the specificity (79.3%). CONCLUSIONS: In our patient populations, the EFNS/PNS criteria were the most sensitive and allowed identification of a highly significantly greater number of patients than Koski et al's criteria. The latter were comparable in specificity with the "definite/probable" EFNS/PNS electrodiagnostic subcategories. More extensive nerve-conduction studies improved diagnostic yield but resulted in loss of specificity.