Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 29
Filter
1.
J Clin Med ; 12(21)2023 Nov 06.
Article in English | MEDLINE | ID: mdl-37959410

ABSTRACT

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system (CNS) caused by reactivation of the polyomavirus JC (JCV) typically in immunocompromised individuals. The risk of PML among rheumatic diseases may be higher for systemic lupus erythematosus (SLE), without, however, a clear association with the type and intensity of background therapy. We present the development and outcome of PML in a 32-year-old female lupus patient under mild immunosuppressive treatment, yet with marked B-cell lymphopenia in the peripheral blood and bone marrow (<1% of total lymphocytes). Despite treatment with the immune checkpoint inhibitor pembrolizumab, the patient showed progressive neurological and brain imaging deterioration and eventually died 15 months after PML diagnosis. To unveil possible underlying genetic liabilities, whole exome sequencing was performed which identified deleterious variants in GATA2 and CDH7 genes, which both have been linked to defective T- and/or B-lymphocyte production. These findings reiterate the possible role of disease-/patient-intrinsic factors, rather than that of drug-induced immunosuppression, in driving immune dysregulation and susceptibility to PML in certain patients with SLE.

2.
Neuroradiology ; 65(8): 1287-1300, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37301785

ABSTRACT

PURPOSE: This study aims to identify common and distinct hemodynamic and functional connectivity (FC) features for self-rated fatigue and depression symptoms in patients with clinically isolated syndrome (CIS) and relapsing-remitting multiple sclerosis (RR-MS). METHODS: Twenty-four CIS, 29 RR-MS patients, and 39 healthy volunteers were examined using resting-state fMRI (rs-fMRI) to obtain whole-brain maps of (i) hemodynamic response patterns (through time shift analysis), (ii) FC (via intrinsic connectivity contrast maps), and (iii) coupling between hemodynamic response patterns and FC. Each regional map was correlated with fatigue scores, controlling for depression, and with depression scores, controlling for fatigue. RESULTS: In CIS patients, the severity of fatigue was associated with accelerated hemodynamic response in the insula, hyperconnectivity of the superior frontal gyrus, and evidence of reduced hemodynamics-FC coupling in the left amygdala. In contrast, depression severity was associated with accelerated hemodynamic response in the right limbic temporal pole, hypoconnectivity of the anterior cingulate gyrus, and increased hemodynamics-FC coupling in the left amygdala. In RR-MS patients, fatigue was associated with accelerated hemodynamic response in the insula and medial superior frontal cortex, increased functional role of the left amygdala, and hypoconnectivity of the dorsal orbitofrontal cortex, while depression symptom severity was linked to delayed hemodynamic response in the medial superior frontal gyrus; hypoconnectivity of the insula, ventromedial thalamus, dorsolateral prefrontal cortex, and posterior cingulate; and decreased hemodynamics-FC coupling of the medial orbitofrontal cortex. CONCLUSION: There are distinct FC and hemodynamic responses, as well as different magnitude and topography of hemodynamic connectivity coupling, associated with fatigue and depression in early and later stages of MS.


Subject(s)
Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , Humans , Multiple Sclerosis/complications , Multiple Sclerosis/diagnostic imaging , Depression/diagnostic imaging , Brain/diagnostic imaging , Fatigue , Magnetic Resonance Imaging
3.
Article in English | MEDLINE | ID: mdl-35351814

ABSTRACT

BACKGROUND AND OBJECTIVES: Autoantibodies against α3-subunit-containing nicotinic acetylcholine receptors (α3-nAChRs), usually measured by radioimmunoprecipitation assay (RIPA), are detected in patients with autoimmune autonomic ganglionopathy (AAG). However, low α3-nAChR antibody levels are frequently detected in other neurologic diseases with questionable significance. Our objective was to develop a method for the selective detection of the potentially pathogenic α3-nAChR antibodies, seemingly present only in patients with AAG. METHODS: The study involved sera from 55 patients from Greece, suspected for autonomic failure, and 13 patients from Italy diagnosed with autonomic failure, positive for α3-nAChR antibodies by RIPA. In addition, sera from 52 patients with Ca2+ channel or Hu antibodies and from 2,628 controls with various neuroimmune diseases were included. A sensitive live cell-based assay (CBA) with α3-nAChR-transfected cells was developed to detect antibodies against the cell-exposed α3-nAChR domain. RESULTS: Twenty-five patients were found α3-nAChR antibody positive by RIPA. Fifteen of 25 patients were also CBA positive. Of interest, all 15 CBA-positive patients had AAG, whereas all 10 CBA-negative patients had other neurologic diseases. RIPA antibody levels of the CBA-negative sera were low, although our CBA could detect dilutions of AAG sera corresponding to equally low RIPA antibody levels. No serum bound to control-transfected cells, and none of the 2,628 controls was α3-CBA positive. DISCUSSION: This study showed that in contrast to the established RIPA for α3-nAChR antibodies, which at low levels is of moderate disease specificity, our CBA seems AAG specific, while at least equally sensitive with the RIPA. This study provides Class II evidence that α3-nAChR CBA is a specific assay for AAG. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that an α3-nAChR cell-based assay is a more specific assay for AAG than the standard RIPA.


Subject(s)
Autoimmune Diseases of the Nervous System , Autoimmune Diseases , Peripheral Nervous System Diseases , Receptors, Nicotinic , Ganglia, Autonomic/metabolism , Ganglia, Autonomic/pathology , Humans , Receptors, Nicotinic/metabolism
4.
Mult Scler J Exp Transl Clin ; 7(3): 20552173211035803, 2021.
Article in English | MEDLINE | ID: mdl-34377528

ABSTRACT

BACKGROUND: Natalizumab is a highly efficacious treatment for relapsing-remitting multiple sclerosis (RRMS). OBJECTIVE: To assess the real-world long-term safety of natalizumab in RRMS. METHODS: This multicenter, 5-year prospective observational study, included adults with RRMS newly initiated on natalizumab as per the approved product label in the routine care in Greece. Safety was evaluated by collecting serious adverse events (SAEs) following study enrollment. RESULTS: Between 19-Apr-2012 and 18-Dec-2014, 304 eligible patients (median age at natalizumab initiation: 38.0 years; median disease duration: 6.2 years) were enrolled by 20 hospital-based neurologists. Over a median treatment duration period of 58.7 months, 50.7% of the patients discontinued natalizumab, mainly due to anti-JCV antibody detection (59.1%). The adverse event treatment discontinuation rate was 5.2%. The SAE incidence rate during the safety data collection period (median: 48.7 months) was 4.6%. The most common SAEs were infections (1.0%), including 2 cases (0.7%) of progressive multifocal leukoencephalopathy (PML), and no other opportunistic infections. PML diagnoses occurred 6.2-6.7 years after natalizumab initiation, and approximately 2 years after first detection of anti-JCV antibody for both patients. The incidence rate of malignancies was 0.7%. CONCLUSION: In real-world settings in Greece, natalizumab displayed an acceptable safety profile, with no new safety signals emerging.

5.
Mult Scler Relat Disord ; 54: 103108, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34198031

ABSTRACT

BACKGROUND: Cognitive disturbances occur in patients with Relapsing Remitting Multiple Sclerosis (RR-MS) and Clinically Isolated Syndrome (CIS). The Multi-Echo-Spin-Echo (MESE) T2-weighted sequence quantifies demyelination, the pathological hallmark of MS, but has not been used for the documentation of the potential relationship between anatomically specific demyelinating changes and cognitive impairment in MS. PURPOSE: To identify markers of regional demyelination in patients with RR-MS and CIS in relation to clinical variables and severity of cognitive impairment. METHODS AND MATERIALS: 37 RR-MS patients, 39 CIS patients and 52 healthy controls (HC) were examined using the MESE sequence. Long T2 and myelin water fraction (MWF) values were measured, serving as indices of intra/extracellular water content and myelin content, respectively, in focal white matter lesions and 12 normal appearing white matter (NAWM) areas of the patients and HC. A comprehensive neuropsychological assessment was administered to all patients. RESULTS: RR-MS patients showed widespread long T2 increases and MWF reductions in NAWM, compared to the respective values of HC (p < 0.001), which correlated with total lesion volume. Among RR-MS patients illness duration correlated negatively with MWF in right hemisphere frontal and periventricular NAWM areas (and positively with corresponding long T2 values). MWF values were lower in the CIS, as compared to the HC group, in the temporal, frontal and periventricular NAWM areas. Focal demyelinating lesions displayed variable higher T2 and lower MWF values, compared to NAWM, closely corresponding to their intensity on T1 sequences. Reduced MWF values and increased long T2 values in right periventricular NAWM were significantly associated with poor visuomotor performance. CONCLUSION: The MESE sequence affords accurate estimation of myelin and water content in NAWM and focal lesions in RR-MS and CIS patients, by means of the MWF and long T2 values, respectively, providing a sensitive index of demyelination associated with visuomotor deficits.


Subject(s)
Demyelinating Diseases , Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , White Matter , Brain/diagnostic imaging , Demyelinating Diseases/complications , Demyelinating Diseases/diagnostic imaging , Humans , Magnetic Resonance Imaging , Multiple Sclerosis, Relapsing-Remitting/complications , Multiple Sclerosis, Relapsing-Remitting/diagnostic imaging , Myelin Sheath , White Matter/diagnostic imaging
6.
J Magn Reson Imaging ; 54(4): 1077-1087, 2021 10.
Article in English | MEDLINE | ID: mdl-33960066

ABSTRACT

BACKGROUND: Although diffusely abnormal white matter (DAWM) is commonly seen in multiple sclerosis (MS), it is rarely considered in clinical/imaging studies. PURPOSE: To evaluate quantitative markers of microstructural changes in DAWM of patients with clinically isolated syndrome (CIS) and relapsing-remitting MS (RR-MS) in relation to MS lesions and degree of neurocognitive impairment, by using a multi-echo spin echo (MESE) Proton Density PD-to-T2 sequence. STUDY TYPE: Prospective, cross-sectional. POPULATION: Thirty-seven RR-MS patients, 33 CIS patients, and 52 healthy controls. FIELD STRENGTH/SEQUENCE: 1.5 T/T1-, T2-weighted, fluid-attenuated inversion recovery, and MESE sequences. ASSESSMENT: Long T2, short T2, and myelin water fraction (MWF) values were estimated as indices of intra/extracellular water content and myelin content, respectively, in DAWM, posterior periventricular normal appearing white matter (NAWM), and focal MS lesions, classified according to their signal intensity on T1 sequences. Patients were, also, administered a battery of neuropsychological tests. STATISTICAL TESTS: Comparisons of T2 and MWF values in DAWM, NAWM, and MS lesions were examined, using two-way mixed analyses of variance. Associations of Grooved Pegboard performance with T2 and MWF values in DAWM and NAWM were assessed using Pearson correlation coefficients. RESULTS: T2 and MWF values of DAWM were intermediate between the respective values of NAWM and T1 hypointense focal lesions, while there was no difference between the respective values of DAWM and T1-isointense lesions. T2 values in DAWM were strongly associated with visuomotor performance in CIS patients. DATA CONCLUSION: Intra/extracellular water and myelin water content of DAWM are similar to those of T1-isointense lesions and predict visuomotor performance in CIS patients. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.


Subject(s)
Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , White Matter , Brain/diagnostic imaging , Cross-Sectional Studies , Humans , Magnetic Resonance Imaging , Multiple Sclerosis, Relapsing-Remitting/diagnostic imaging , Prospective Studies , White Matter/diagnostic imaging
8.
Open Med (Wars) ; 15(1): 520-530, 2020.
Article in English | MEDLINE | ID: mdl-33336007

ABSTRACT

This study aims to examine a time-extended dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) protocol and report a comparative study with three different pharmacokinetic (PK) models, for accurate determination of subtle blood-brain barrier (BBB) disruption in patients with multiple sclerosis (MS). This time-extended DCE-MRI perfusion protocol, called Snaps, was applied on 24 active demyelinating lesions of 12 MS patients. Statistical analysis was performed for both protocols through three different PK models. The Snaps protocol achieved triple the window time of perfusion observation by extending the magnetic resonance acquisition time by less than 2 min on average for all patients. In addition, the statistical analysis in terms of adj-R 2 goodness of fit demonstrated that the Snaps protocol outperformed the conventional DCE-MRI protocol by detecting 49% more pixels on average. The exclusive pixels identified from the Snaps protocol lie in the low k trans range, potentially reflecting areas with subtle BBB disruption. Finally, the extended Tofts model was found to have the highest fitting accuracy for both analyzed protocols. The previously proposed time-extended DCE protocol, called Snaps, provides additional temporal perfusion information at the expense of a minimal extension of the conventional DCE acquisition time.

9.
Mult Scler Relat Disord ; 45: 102356, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32659736

ABSTRACT

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) has only rarely been reported in patients with multiple sclerosis (MS). METHODS: Case report of a patient with relapsing remitting (RR) MS patient on interferon (INF) treatment, who developed posterior fossa PRES. RESULTS: A 46-year-old male diagnosed with RR MS in 2010 was placed on INF beta-1a therapy. He remained in clinical remission for seven years. He then presented with headache of one month duration and worsening upper extremity ataxia. Cranial MRI revealed two new enhancing cerebellar lesions (one with tumefactive features). Within the next 10 days the patient developed severe holocephalic headache, vomiting, altered consciousness and gait instability. Urgent brain MRI revealed diffuse hyperintense lesions in T2WI and FLAIR sequences in bilateral cerebellar hemispheres and the right thalamus, with marked swelling, increased diffusivity indicative of vasogenic edema and patchy-nodular enhancement, while smaller lesions were also found in posterior temporal, parietal and occipital lobes. Severely elevated blood pressure was noted. Treatment with hypertonic agents, esmolol drip and IV steroids was instituted, resulting in remarkable improvement within the next several days. Repeat MRI showed almost complete resolution of the cerebellar lesions. Interferon beta was discontinued and blood pressure remained well controlled. CONCLUSIONS: Patients with RR MS on IFN beta therapy can develop PRES via the combination of hypertension and endothelial dysfunction by IFN, even when stable on this treatment. Neurologists should be keen to differentiate the appearance of PRES lesions from those of fulminant MS relapse, opportunistic infections or malignancy.


Subject(s)
Multiple Sclerosis , Posterior Leukoencephalopathy Syndrome , Humans , Immunotherapy , Incidence , Interferons , Male , Middle Aged , Posterior Leukoencephalopathy Syndrome/diagnostic imaging
10.
J Health Psychol ; 25(13-14): 2096-2105, 2020.
Article in English | MEDLINE | ID: mdl-29992828

ABSTRACT

This prospective study aimed to examine whether illness-related negative emotions mediate the relationship of cognitive reappraisal and expressive suppression to the well-being of 99 patients with rheumatoid arthritis or multiple sclerosis. After adjusting for disease and patient-related parameters, only cognitive reappraisal was associated with physical and psychological well-being through emotions. Expressive suppression was associated with psychological well-being only for patients reporting less use of cognitive reappraisal. These results underscore the need for prospective studies that will investigate the long-term impact of emotion regulation on adaptation to chronic illness and the conditions under which this impact takes place.


Subject(s)
Autoimmune Diseases , Emotional Regulation , Autoimmune Diseases/psychology , Chronic Disease , Cognition , Emotions , Humans , Prospective Studies
11.
J Health Psychol ; 22(13): 1691-1700, 2017 11.
Article in English | MEDLINE | ID: mdl-26962131

ABSTRACT

We examined whether the dispositional optimism of patients suffering from an autoimmune disease as well as of their partners can predict, at a dyadic level, their representations of illness consequences, and personal and treatment control, assessed 1 year later. Patient optimism predicted several patient and partner illness representations. Partner optimism was unrelated to own or patient illness representations. Results highlight the strong long-term predictive power of patient optimism and underline the importance of the interpersonal function of personality traits. At the same time, study findings indicate that the dyadic effects of optimism are complex and probably conditional on several factors.


Subject(s)
Autoimmune Diseases/psychology , Family Characteristics , Optimism , Personality , Sexual Partners/psychology , Attitude to Health , Autoimmune Diseases/diagnosis , Female , Humans , Male , Marriage/psychology , Marriage/statistics & numerical data , Middle Aged , Prognosis
12.
J Neurochem ; 133(1): 73-82, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25620628

ABSTRACT

Glutamate Dehydrogenase (GDH) is central to the metabolism of glutamate, a major excitatory transmitter in mammalian central nervous system (CNS). hGDH1 is activated by ADP and L-leucine and powerfully inhibited by GTP. Besides this housekeeping hGDH1, duplication led to an hGDH2 isoform that is expressed in the human brain dissociating its function from GTP control. The novel enzyme has reduced basal activity (4-6% of capacity) while remaining remarkably responsive to ADP/L-leucine activation. While the molecular basis of this evolutionary adaptation remains unclear, substitution of Ser for Arg443 in hGDH1 is shown to diminish basal activity (< 2% of capacity) and abrogate L-leucine activation. To explore whether the Arg443Ser mutation disrupts hydrogen bonding between Arg443 and Ser409 of adjacent monomers in the regulatory domain ('antenna'), we replaced Ser409 by Arg or Asp in hGDH1. The Ser409Arg-1 change essentially replicated the Arg443Ser-1 mutation effects. Molecular dynamics simulation predicted that Ser409 and Arg443 of neighboring monomers come in close proximity in the open conformation and that introduction of Ser443-1 or Arg409-1 causes them to separate with the swap mutation (Arg409/Ser443) reinstating their proximity. A swapped Ser409Arg/Arg443Ser-1 mutant protein, obtained in recombinant form, regained most of the wild-type hGDH1 properties. Also, when Ser443 was replaced by Arg443 in hGDH2 (as occurs in hGDH1), the Ser443Arg-2 mutant acquired most of the hGDH1 properties. Hence, side-chain interactions between 409 and 443 positions in the 'antenna' region of hGDHs are crucial for basal catalytic activity, allosteric regulation, and relative resistance to thermal inactivation.


Subject(s)
Glutamate Dehydrogenase/metabolism , Allosteric Regulation/genetics , Amino Acid Substitution , Computer Simulation , Glutamate Dehydrogenase/chemistry , Glutamate Dehydrogenase/genetics , Hot Temperature , Humans , Isoenzymes/genetics , Isoenzymes/metabolism , Kinetics , Models, Molecular , Mutagenesis, Site-Directed , Mutation/physiology , Protein Denaturation
13.
Neuroimmunomodulation ; 22(3): 181-95, 2015.
Article in English | MEDLINE | ID: mdl-24852748

ABSTRACT

Multiple sclerosis (MS) is a prototypic autoimmune inflammatory disorder of the central nervous system (CNS). MS pathogenesis is a complex phenomenon that is influenced by genetic and environmental factors that lead to the dysregulation of immune homeostasis and tolerance. It has been shown that pathogenic T lymphocyte subsets, such as T helper 1 (Th1) and Th17 cells, play a crucial role in the autoimmune cascade influencing disease initiation, progression and subsequent tissue damage during MS. On the other hand, several mechanisms have been described in both patients and animal models of MS with the potential to modulate myelin-specific autoimmune responses and to facilitate amelioration of disease pathology. To this end, regulatory T cells (Tregs) are considered to be a powerful cell subset not only in the maintenance of homeostasis but also in the re-establishment of tolerance. Along these lines, other cell subsets such as dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs), γδ T cells and natural killer (NK) cells have been shown to regulate the autoimmune response in the CNS under certain circumstances. This review will attempt to summarize the relevant knowledge of the regulatory mechanisms exerted by immune cells in MS that could hold the promise for the design of novel therapeutic strategies.


Subject(s)
Autoimmunity , Encephalomyelitis, Autoimmune, Experimental/immunology , Encephalomyelitis, Autoimmune, Experimental/therapy , Multiple Sclerosis/immunology , Multiple Sclerosis/therapy , Animals , Humans , T-Lymphocyte Subsets/physiology
14.
Behav Neurol ; 2014: 252419, 2014.
Article in English | MEDLINE | ID: mdl-24825950

ABSTRACT

BACKGROUND: Patients with clinically isolated syndrome (CIS) demonstrate brain hemodynamic changes and also suffer from difficulties in processing speed, memory, and executive functions. OBJECTIVE: To explore whether brain hemodynamic disturbances in CIS patients correlate with executive functions. METHODS: Thirty CIS patients and forty-three healthy subjects, matched for age, gender, education level, and FSIQ, were administered tests of visuomotor learning and set shifting ability. Cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) values were estimated in normal-appearing white matter (NAWM) and normal-appearing deep gray Matter (NADGM) structures, using a perfusion MRI technique. RESULTS: CIS patients showed significantly elevated reaction time (RT) on both tasks, while their CBV and MTT values were globally increased, probably due to inflammatory vasodilation. Significantly, positive correlation coefficients were found between error rates on the inhibition condition of the visuomotor learning task and CBV values in occipital, periventricular NAWM and both thalami. On the set shifting condition of the respective task significant, positive associations were found between error rates and CBV values in the semioval center and periventricular NAWM bilaterally. CONCLUSION: Impaired executive function in CIS patients correlated positively with elevated regional CBV values thought to reflect inflammatory processes.


Subject(s)
Brain/physiopathology , Cerebrovascular Circulation/physiology , Demyelinating Diseases/physiopathology , Executive Function/physiology , Motor Skills/physiology , Adolescent , Adult , Demyelinating Diseases/psychology , Female , Hemodynamics/physiology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests , Reaction Time/physiology , Young Adult
15.
Neurochem Res ; 39(3): 471-86, 2014.
Article in English | MEDLINE | ID: mdl-24515454

ABSTRACT

Mammalian glutamate dehydrogenase (GDH) catalyzes the reversible inter-conversion of glutamate to α-ketoglutarate and ammonia, interconnecting carbon skeleton and nitrogen metabolism. In addition, it functions as an energy switch by its ability to fuel the Krebs cycle depending on the energy status of the cell. As GDH lies at the intersection of several metabolic pathways, its activity is tightly regulated by several allosteric compounds that are metabolic intermediates. In contrast to other mammals that have a single GDH-encoding gene, humans and great apes possess two isoforms of GDH (hGDH1 and hGDH2, encoded by the GLUD1 and GLUD2 genes, respectively) with distinct regulation pattern, but remarkable sequence similarity (they differ, in their mature form, in only 15 of their 505 amino-acids). The GLUD2 gene is considered a very young gene, emerging from the GLUD1 gene through retro-position only recently (<23 million years ago). The new hGDH2 iso-enzyme, through random mutations and natural selection, is thought to have conferred an evolutionary advantage that helped its persistence through primate evolution. The properties of the two highly homologous human GDHs have been studied using purified recombinant hGDH1 and hGDH2 proteins obtained by expression of the corresponding cDNAs in Sf21 cells. According to these studies, in contrast to hGDH1 that maintains basal activity at 35-40 % of its maximal, hGDH2 displays low basal activity that is highly responsive to activation by rising levels of ADP and/or L-leucine which can also act synergistically. While hGDH1 is inhibited potently by GTP, hGDH2 shows remarkable GTP resistance. Furthermore, the two iso-enzymes are differentially inhibited by estrogens, polyamines and neuroleptics, and also differ in heat-lability. To elucidate the molecular mechanisms that underlie these different regulation patterns of the two iso-enzymes (and consequently the evolutionary adaptation of hGDH2 to a new functional role), we have performed mutagenesis at sites of difference in their amino acid sequence. Results showed that the low basal activity, heat-lability and estrogen sensitivity of hGDH2 could be, at least partially, ascribed to the Arg443Ser evolutionary change, whereas resistance to GTP inhibition has been attributed to the Gly456Ala change. Other amino acid substitutions studied thus far cannot explain all the remaining functional differences between the two iso-enzymes. Also, the Arg443Ser/Gly456Ala double mutation in hGDH1 approached the properties of wild-type hGDH2, without being identical to it. The insights into the structural mechanism of enzymatic regulation and the implications in cell biology provided by these findings are discussed.


Subject(s)
Biological Evolution , Glutamate Dehydrogenase/metabolism , Mutation/genetics , Allosteric Regulation/genetics , Allosteric Regulation/physiology , Animals , Glutamate Dehydrogenase/genetics , Humans , Isoenzymes/genetics , Isoenzymes/metabolism , Protein Binding
16.
Semin Arthritis Rheum ; 43(6): 751-8, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24332007

ABSTRACT

OBJECTIVES: The coexistence of systemic lupus erythematosus (SLE) and multiple sclerosis (MS) in the same individual has rarely been described. Our objective was to report on the prevalence, clinical characteristics, and prognosis of cases fulfilling the criteria for both SLE and MS. METHODS: We utilized existing patient cohorts from the Departments of Rheumatology and Neurology, University of Crete, and screened patients diagnosed with either SLE (n = 728) or MS (n = 819) for features of both diseases. The clinical, laboratory, and neuroimaging findings were assessed. RESULTS: We identified nine patients who fulfilled the diagnostic criteria for both SLE and MS, corresponding to a prevalence rate of 1.0-1.2% in each cohort. All patients were women, with an average age at SLE diagnosis of 42.1 years (range: 34-56 years). The diagnosis of SLE preceded the development of MS in five patients, with a time lag ≤ 5 years in four of them. Initial presentation of MS included spinal symptoms in seven patients. All patients had features of mild SLE with predominantly cutaneous, mucosal, and musculoskeletal manifestations. Accordingly, therapeutic decisions were mainly guided by the severity of the neurological syndrome. During the median follow-up of 4 years (range: 1-10 years), three patients remained stable and the remaining experienced gradual deterioration in their neurological status. SLE remained quiescent in all patients while on standard immunomodulatory MS therapy. CONCLUSIONS: Occurrence of both diseases in the same individual is rare, corroborating data that suggest distinct molecular signatures. SLE and MS coexistence was not associated with a severe phenotype for either entity.


Subject(s)
Antirheumatic Agents/therapeutic use , Immunologic Factors/therapeutic use , Immunosuppressive Agents/therapeutic use , Lupus Erythematosus, Systemic/epidemiology , Multiple Sclerosis/epidemiology , Adrenal Cortex Hormones/therapeutic use , Adult , Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Monoclonal, Murine-Derived/therapeutic use , Azathioprine/therapeutic use , Comorbidity , Female , Glatiramer Acetate , Greece/epidemiology , Humans , Hydroxychloroquine/therapeutic use , Interferon-beta/therapeutic use , Lupus Erythematosus, Systemic/drug therapy , Male , Methotrexate/therapeutic use , Middle Aged , Multiple Sclerosis/drug therapy , Natalizumab , Peptides/therapeutic use , Prevalence , Rituximab
17.
Mult Scler Relat Disord ; 3(2): 203-10, 2014 Mar.
Article in English | MEDLINE | ID: mdl-25878008

ABSTRACT

BACKGROUND & OBJECTIVES: Progressive multifocal leukoencephalopathy (PML) may complicate natalizumab treatment in multiple sclerosis patients. We sought to characterize the clinical and laboratory features of natalizumab-related PML (NR-PML) cases from Greece. METHODS: Pharmaceutical industry, national drug authorities and all neurology departments within the Greek territory were asked to provide data for cases of NR-PML until October 2012. Collected cases were classified according to their level of diagnostic certainty using the five-level system introduced by Mentzer et al. (2012). RESULTS: Thirteen NR-PML cases were identified by the neurology departments. Data were provided for only 9 cases. PML manifestations appeared after a median number of 40 (21-52) natalizumab infusions. All but two patients were treated with plasma exchange and some were treated adjunctively with mirtazapine while the others were treated with mefloquine. IRIS developed in 6 cases after a median time of 6 (2-10) weeks from PML presentation and were treated with different regimens of corticosteroids. PML was fatal in 3 cases. The median EDSS after a median follow-up time of 12 (8-23) months in the surviving cases was 4.75 (2-8.5). CONCLUSIONS: Outcomes for collected NR-PML cases varied from death to returning to baseline. Close surveillance is essential for early diagnosis and treatment of NR-PML patients.

18.
Sleep Breath ; 17(4): 1129-35, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23389837

ABSTRACT

PURPOSE: The multi-organ involvement of mitochondrial diseases means that patients are likely to be more vulnerable to sleep disturbances. We aimed to assess if early recognition and treatment of obstructive sleep apnea (OSA) in patients with Leigh disease may influence primary disease outcome. METHODS: We describe a case of adult-onset Leigh disease presenting as severe brainstem encephalopathy of subacute onset. Based on the clinical symptoms that developed after the appearance of the neurological disease, an attended overnight polysomnography examination was performed. RESULTS: A marked clinical recovery was seen after administration of high doses of thiamine, coenzyme Q, L-carnitine, and vitamins C and E, combined with effective treatment with continuous positive airway pressure for the underlying severe obstructive sleep apnea (OSA). The latter condition was diagnosed on the basis of suggestive symptoms that appeared a few weeks before the establishment of the neurological disease. The improvement in the neurological disease (based on clinical and brain MRI features) with the appropriate medical treatment also resulted in a significant improvement in the OSA. CONCLUSIONS: Early recognition and treatment of sleep apnea may not only improve sleep and overall quality of life but also ameliorate the deleterious effects of nocturnal desaturations on the neurological features. This may be crucial for disease outcome when added to the generally advised pharmacological therapy.


Subject(s)
Carnitine/administration & dosage , Leigh Disease/drug therapy , Sleep Apnea, Obstructive/drug therapy , Thiamine/administration & dosage , Ubiquinone/administration & dosage , Vitamin D/administration & dosage , Vitamin E/administration & dosage , Adult , Brain/drug effects , Brain/pathology , Dose-Response Relationship, Drug , Drug Therapy, Combination , Humans , Leigh Disease/diagnosis , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Male , Neurologic Examination/drug effects , Polysomnography/drug effects , Sleep Apnea, Obstructive/diagnosis
19.
Behav Neurol ; 25(4): 311-26, 2012.
Article in English | MEDLINE | ID: mdl-22713377

ABSTRACT

The study investigates primary and secondary verbal memory and motor/executive functions (response inhibition and strategy shifting ability) in multiple sclerosis (MS) patients with clinically isolated syndrome (CIS). We studied 44 CIS patients and compared them to 49 patients with relapsing remitting MS (RR-MS) displaying mild disability and to a large cohort of age- and education level-matched healthy volunteers(n=230). Results showed that both CIS and RR-MS patients evidenced a disproportionate impairment in the immediate and delayed recall of the second (as compared to the first) of two short narratives of the Logical Memory WMS-III subtest, and reduced performance on the Memory for Digits-Forward. Performance of either group on the executive tasks was not impaired, showing evidence of a reversed speed-accuracy trade-off. Illness duration emerged as a significant predictor of memory and executive task performance. Clinical, psychoemotional, and brain imaging findings were also examined as potential correlates of memory deficits and disease progression among CIS patients. These findings may signify early-onset decline of specific cognitive functions in CIS, which merits regular follow-up assessments and monitoring of psychoemotional adaptation and everyday functioning.


Subject(s)
Memory Disorders/complications , Memory Disorders/psychology , Multiple Sclerosis/complications , Multiple Sclerosis/psychology , Adolescent , Brain/pathology , Child , Cognition Disorders/complications , Cognition Disorders/epidemiology , Disability Evaluation , Disease Progression , Emotions/physiology , Executive Function/physiology , Female , Humans , Image Processing, Computer-Assisted , Intelligence Tests , Magnetic Resonance Imaging , Male , Memory Disorders/pathology , Memory, Episodic , Mental Recall/physiology , Multiple Sclerosis/pathology , Multiple Sclerosis, Relapsing-Remitting/complications , Multiple Sclerosis, Relapsing-Remitting/psychology , Neuropsychological Tests , Reaction Time/physiology , Young Adult
20.
Magn Reson Med ; 68(6): 1932-42, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22367604

ABSTRACT

The dynamic susceptibility contrast magnetic resonance imaging perfusion technique was used to investigate possible hemodynamic changes in normal appearing white matter and deep gray matter (DGM) of 30 patients with clinically isolated syndrome (CIS) and 30 patients with relapsing-remitting multiple sclerosis. Thirty normal volunteers were studied as controls. Cerebral blood volume, cerebral blood flow (CBF), and mean transit time values were estimated. Normalization was achieved for each subject with respect to average values of CBF and mean transit time of the hippocampi's dentate gyrus. Measurements concerned three regions of normal white matter of normal volunteers, normal appearing white matter of CIS and patients with relapsing-remitting multiple sclerosis, and DGM regions, bilaterally. All measured normal appearing white matter and DGM regions of the patients with CIS had significantly higher cerebral blood volume and mean transit time values, while averaged DGM regions had significantly lower CBF values, compared to those of normal volunteers (P < 0.001). Regarding patients with relapsing-remitting multiple sclerosis, all measured normal appearing white matter and DGM regions showed lower CBF values than those of normal volunteers and lower cerebral blood volume and CBF values compared to patients with CIS (P < 0.001). These data provide strong evidence that hemodynamic changes--affecting both white and DGM--may occur even at the earliest stage of multiple sclerosis, with CIS patients being significantly different than relapsing-remitting multiple sclerosis patients.


Subject(s)
Cerebrovascular Circulation , Demyelinating Diseases/physiopathology , Magnetic Resonance Imaging/methods , Multiple Sclerosis/physiopathology , Nerve Fibers, Myelinated , Neurons , Adult , Blood Flow Velocity , Demyelinating Diseases/complications , Female , Humans , Male , Multiple Sclerosis/complications , Reproducibility of Results , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...