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H Kwiecinski

Publications and source records attributed to H Kwiecinski.

15 recordsLinked to original sources
PubMed2006

APOE epsilon variation in multiple sclerosis susceptibility and disease severity: some answers.

BACKGROUND: Previous studies have examined the role of APOE variation in multiple sclerosis (MS), but have lacked the statistical power to detect modest genetic influences on risk and disease severity. The meta- and pooled analyses presented here utilize the largest collection, to date, of MS cases, controls, and families genotyped for the APOE epsilon polymorphism. METHODS: Studies of MS and APOE were identified by searches of PubMed, Biosis, Web of Science, Cochrane Review, and Embase. When possible, authors were contacted for individual genotype data. Meta-analyses of MS case-control data and family-based analyses were performed to assess the association of APOE epsilon genotype with disease risk. Pooled analyses of MS cases were also performed to assess the influence of APOE epsilon genotype on disease severity. RESULTS: A total of 22 studies (3,299 MS cases and 2,532 controls) were available for meta-analysis. No effect of epsilon2 or epsilon4 status on MS risk was observed (summary OR 1.14, 95% CI 0.96-1.34 and OR 0.89, 95% CI 0.78-1.01). Results obtained from analyses of APOE genotypes in 1,279 MS families were also negative (p = 0.61). Finally, results from pooled analyses of 4,048 MS cases also argue strongly that APOE epsilon status does not distinguish a relapsing-remitting from primary progressive disease course, or influence disease severity, as measured by the Expanded Disability Status Scale and disease duration. CONCLUSION: Overall, these findings do not support a role for APOE in multiple sclerosis, and underscore the importance of using large sample sizes to detect modest genetic effects, particularly in studies of genotype-phenotype relationships.

Alleles↗
PubMed2004

Correlating phenotype and genotype in the periodic paralyses.

BACKGROUND: Periodic paralyses and paramyotonia congenita are rare disorders causing disabling weakness and myotonia. Mutations in sodium, calcium, and potassium channels have been recognized as causing disease. OBJECTIVE: To analyze the clinical phenotype of patients with and without discernible genotype and to identify other mutations in ion channel genes associated with disease. METHODS: The authors have reviewed clinical data in patients with a diagnosis of hypokalemic periodic paralysis (56 kindreds, 71 patients), hyperkalemic periodic paralysis (47 kindreds, 99 patients), and paramyotonia congenita (24 kindreds, 56 patients). For those patients without one of the classically known mutations, the authors analyzed the entire coding region of the SCN4A, KCNE3, and KCNJ2 genes and portions of the coding region of the CACNA1S gene in order to identify new mutations. RESULTS: Mutations were identified in approximately two thirds of kindreds with periodic paralysis or paramyotonia congenita. The authors found differences between the disorders and between those with and without identified mutations in terms of age at onset, frequency of attacks, duration of attacks, fixed proximal weakness, precipitants of attacks, myotonia, electrophysiologic studies, serum potassium levels, muscle biopsy, response to potassium administration, and response to treatment with acetazolamide. CONCLUSIONS: Hypokalemic periodic paralysis, hyperkalemic periodic paralysis, and paramyotonia congenita may be distinguished based on clinical data. This series of 226 patients (127 kindreds) confirms some clinical features of this disorder with notable exceptions: In this series, patients without mutations had a less typical clinical presentation including an older age at onset, no changes in diet as a precipitant, and absence of vacuolar myopathy on muscle biopsy.

Adolescent↗
PubMed2004

Mutations and polymorphisms of the CLCN2 gene in idiopathic epilepsy.

The authors analyzed the CLCN2 chloride channel gene in 112 probands with familial epilepsy, detecting 18 common polymorphisms. Two brothers with generalized epilepsy and their asymptomatic father, and a father and son with focal epilepsy carried variants of possible functional significance that were not found in 192 controls. The authors conclude that CLCN2 mutations may be a rare cause of familial epilepsy. Further studies are needed to test if polymorphisms in this gene are associated with epilepsy.

Adult↗
PubMed2004

Improvement of motor function in early Parkinson disease by safinamide.

A median safinamide (SAF) dose of 70 mg/day (range 40 to 90 mg/day) increased the percentage of parkinsonian patients improving their motor scores by > or =30% from baseline (responders) after 3 months from 21.4% (placebo) to 37.5% (p < 0.05, calculated by logistic regression analysis). In a subgroup of 101 patients under stable treatment with a single dopamine agonist, addition of SAF magnified the response (47.1% responders, mean 4.7-point motor score decrease; p > or = 0.05). These results suggest that doses of SAF exerting ion channel block and glutamate release inhibition add to its symptomatic effect and warrant exploration of higher doses.

Adult↗
PubMed2004

Association of apolipoprotein E and myeloperoxidase genotypes to clinical course of familial and sporadic multiple sclerosis.

The importance of apolipoprotein E (ApoE) and myeloperoxidase (MPO) genotypes in the clinical characteristics of multiple sclerosis (MS) has been recently emphasized. In a large group of Polish patients we have tested the hypothesis that polymorphism in ApoE and MPO genes may influence the course of the disease. Genotypes were determined in 117 MS patients (74 females and 43 males; 99 sporadic and 18 familial cases) with mean EDSS of 3.6, mean age of 44. 1 years, mean duration of the disease 12.8 years and mean onset of MS at 31.2 years, and in 100 healthy controls. The relationship between ApoE and MPO genes' polymorphism and the MS activity as well as the defect of remyelination (diffuse demyelination) and brain atrophy on MRI were analysed. The ApoE epsilon4 allele was not related to the disease course or the ApoE epsilon2 to the intensity of demyelination on MRI. The genotype MPO G/G was found in all familial MS and in 57% (56/99) of sporadic cases. This genotype was also related to more pronounced brain atrophy on MRI. The MPO G/G subpopulation was characterized by a significantly higher proportion of patients with secondary progressive MS (P < 0.05) and by a higher value of EDSS. According to our results the MPO G allele is frequently found (in 96% of cases) among Polish patients with MS. More severe nervous tissue damage in the MPO G/G form can be explained by the mechanism of accelerated oxidative stress. It seems that MPO G/G genotype may be one of the genetic factors influencing the progression rate of disability in MS patients.

Adolescent↗
PubMed2001

Factor V Leiden, prothrombin gene G20210A variant, and methylenetetrahydrofolate reductase C677T genotype in young adults with ischemic stroke.

Ischemic stroke in young adults is a well-known disease, but despite extensive clinical and laboratory investigations, its etiology remains unclear in approximately half of the cases. We examined the prevalence of factor V Leiden, the prothrombin G20210A genotype, and the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene in 100 patients (51 males and 49 females) who survived an ischemic stroke without a cardiac embolic source at an age < or = 45 years, and in 238 healthy control subjects from the same geographic area. The patients were selected for study only if the diagnosis of stroke was documented by computed tomography scan or nuclear magnetic resonance (NMR) of the brain, or both. Heterozygosity for the FV Leiden mutation was found in 3 patients (3.0%) and in 10 control subjects (4.2%). Two patients (2.0%) and five control subjects (2.1%) were heterozygous for the prothrombin G20210A mutation. The frequencies of the MTHFR 677TT, CT, and CC genotypes in the patient group were 12%, 37%, and 51%, respectively, and were not significantly different from those in control subjects (11%, 40%, and 49%, respectively). In conclusion, our results indicate that FV Leiden mutation, prothrombin G20210A genotype, and homozygosity for the C677T mutation in the MTHFR gene are not associated with an increased risk for ischemic stroke in young adults.

Adolescent↗
PubMed2000

Mechanism of inverted activation of ClC-1 channels caused by a novel myotonia congenita mutation.

The voltage-gated chloride channel ClC-1 is the major contributor of membrane conductance in skeletal muscle and has been associated with the inherited muscular disorder myotonia congenita. Here, we report a novel mutation identified in a recessive myotonia congenita family. This mutation, Gly-499 to Arg (G499R) is located in the putative transmembrane domain 10 of the ClC-1 protein. In contrast to normal ClC-1 channels that deactivate upon hyperpolarization, functional expression of G499R ClC-1 yielded a hyperpolarization-activated chloride current when measured in the presence of a high (134 mM) intracellular chloride concentration. Current was abolished when measured with a physiological chloride transmembrane gradient. Electrophysiological analysis of other Gly-499 mutants (G499K, G499Q, and G499E) suggests that the positive charge introduced by the G499R mutation may be responsible for this unique gating behavior. To further explore the function of domain 10, we mutated two charged residues near Gly-499 of ClC-1. Functional analyses of R496Q, R496Q/G499R, R496K, and E500Q mutant channels suggest that the charged residues in domain 10 are important for normal channel function. Study of these mutants may shed further light on the structure and voltage-gating of this channel.

Cell Line↗
PubMed1999

Characterization of a new sodium channel mutation at arginine 1448 associated with moderate Paramyotonia congenita in humans.

1. Paramyotonia congenita is a temperature-sensitive skeletal muscle disorder caused by missense mutations that occur in the adult skeletal muscle voltage-gated sodium channel. We report here the identification of a new genetic mutation in a family with the paramyotonia congenita phenotype. 2. Single-strand conformation polymorphism analysis and DNA sequencing showed that the defect was linked to a single nucleotide substitution causing an amino acid change from an arginine to a serine at position 1448 in the human sodium channel alpha-subunit. 3. Expression of the altered protein in human embryonic kidney (HEK) 293 cells revealed several defects in channel function: (i) the rate of fast inactivation was slower in the mutant channel compared with wild-type, (ii) steady-state fast inactivation was shifted towards hyperpolarizing potentials, (iii) the R1448S channels deactivated much more slowly, and (iv) the mutant channels recovered from the fast inactivated state more rapidly. 4. By contrast, the activation curve, steady-state slow inactivation and the rate of onset and recovery from slow inactivation were not altered by the R1448S mutation. 5. These data show that the defects observed in the sodium channel function could well explain the onset of the paramyotonia congenita in this family and emphasize the role of segment S4 of domain IV in sodium channel inactivation.

Amino Acid Substitution↗
PubMed1999

Dissections after childbirth.

The occurrence of spontaneous internal carotid or vertebral artery dissection after childbirth remains rare. To our knowledge, seven cases of arterial dissection in the postpartum period have been described in the literature as single case reports. We report four additional cases of internal carotid and vertebral artery dissection in the puerperal period, documented by angiography. Physicians should consider the possibility of arterial dissection in any young patient presenting with acute ischemic stroke, including women in the postpartum period. The availability of modern noninvasive ultrasound and imaging techniques may result in earlier diagnosis and facilitate identification of this condition.

Adult↗
PubMed1999

Immunochemical quantification of glycoconjugates in serum and cerebrospinal fluid of amyotrophic lateral sclerosis patients.

Glycoconjugates in the serum of 73 patients with amyotrophic lateral sclerosis (ALS), 21 cases of other motor neuron diseases and 20 healthy controls were determined. Cerebrospinal fluid (CSF) was studied in 64, 7 and 10 of these subjects, respectively. The level of sialic acid containing glycoconjugates, detected by Maakia amurensis agglutinin (MAA), was decreased in the serum of 61.6% of the ALS patients, while in the CSF it was decreased, on average, in 75% of these cases. Only in single ALS cases was the concentration of these glycoconjugates increased. There was no correlation between the content of MAA-labelled glycoconjugates both in serum and CSF and the titre of sialic acid containing anti-GM1 gangliosides. The glycoconjugates, detected by peanut agglutinin (PNA) which recognizes the disaccharide galactose beta(1-3)N- acetylgalactosamine (GGN), were decreased in the serum of 78.1% of ALS patients, while in CSF they were increased in 54.7% of these cases. There was no correlation between the concentration of PNA-labelled glycoconjugates both in serum and CSF as well as the titre of antibodies against GGN-containing anti-GM1 and anti- AGM1 gangliosides. Changes in the level of the MAA- and PNA- labelled glycoconjugates, as well as the titre of anti-GM1 and anti-AGM1 gangliosides antibodies were not specific for ALS. They were also observed in some cases of other motor neuron diseases. The low level of the lectin-labelled glycoconjugates in serum and partly in CSF of the majority of ALS patients is possibly the consequence of their accelerated clearance and/or specific inactivation by the formation of immune complexes or epitope binding. Degeneration of neurons and muscle cells could also be responsible. The relatively low incidence of high anti- glycolipids antibodies titre may be, at least partly, connected with the low concentration of the appropriate antigens. The increased content of PNA-labelled glycoconjugates in the CSF of the majority of ALS patients, together with the low incidence of high titre of antibodies against the appropriate glycolipids, could indicate that in CSF this lectin binds to the GGN epitope of glycoproteins rather than to the GGN epitope of glycolipids.

Adult↗
PubMed1995

Creutzfeldt-Jakob disease with Alzheimer-type A beta-reactive amyloid plaques.

Creutzfeldt-Jakob disease and Gerstmann-Sträussler-Scheinker syndrome are classified as transmissible cerebral amyloidoses, in contrast to the non-transmissible amyloidoses of Alzheimer's disease type. While the aetiologies of Creutzfeldt-Jakob disease and Alzheimer's disease and the molecular composition of their amyloids are different, similar basic pathogenetic mechanisms operate in both diseases through synthesis and processing of amyloid precursor proteins, to produce an accumulation of amyloid deposits. We report here a case of Creutzfeldt-Jakob disease exhibiting numerous diffuse A beta immunoreactive plaques, thus presenting features of both Creutzfeldt-Jakob disease and Alzheimer's disease. The existence of such cases underlines the existence of a 'grey' area between the two types of amyloidoses.

Adult↗
PubMed1992

Tubulovesicular structures in Creutzfeldt-Jakob disease.

By electron microscopy tubulovesicular structures (TVS) have been consistently observed in brain tissue of transmissible spongiform encephalopathies such as natural and experimental scrapie, bovine spongiform encephalopathy and experimentally induced, but not naturally occurring, Creutzfeldt-Jakob disease (CJD). For the first time we report here the presence of TVS in human brains with CJD as detected by transmission electron microscopy. TVS were observed in all three CJD specimens (two biopsies, one autopsy), but they were rare and were found only in one or two location(s) per grid. TVS were seen in distended pre- and postsynaptic terminals and measured approximately 35 nm in diameter; they were smaller and of higher electron density than synaptic vesicles. Their occurrence in all types of transmissible spongiform encephalopathies irrespective of the affected host and the strain of the infectious agent suggests their biological significance.

Aged↗
PubMed1992

Modeling ion permeation through batrachotoxin-modified Na+ channels from rat skeletal muscle with a multi-ion pore.

The mechanism of ion permeation through Na+ channels that have been modified by batrachotoxin (BTX) and inserted into planar bilayers has been generally described by models based on single-ion occupancy, with or without an influence of negative surface charge, depending on the tissue source. For native Na+ channels there is evidence suggestive of a multi-ion conduction mechanism. To explore the question of ion occupancy, we have reexamined permeation of Na+, Li+, and K+ through BTX-modified Na+ channels from rat skeletal muscle. Single-channel current-voltage (I-V) behavior was studied in neutral lipid bilayers in the presence of symmetrical Na+ concentrations ranging from 0.5 to 3,000 mM. The dependence of unitary current on the mole fraction of Na+ was also examined in symmetrical mixtures of Na(+)-Li+ and Na(+)-K+ at a constant total ionic strength of 206 and 2,006 mM. The dependence of unitary conductance on symmetrical Na+ concentration does not exhibit Michaelis-Menten behavior characteristic of single-ion occupancy but can be simulated by an Eyring-type model with three barriers and two sites (3B2S) that includes double occupancy and ion-ion repulsion. Best-fit energy barrier profiles for Na+, Li+, and K+ were obtained by nonlinear curve fitting of I-V data using the 3B2S model. The Na(+)-Li+ and Na(+)-K+ mole-fraction experiments do not exhibit an anomalous mole-fraction effect. However, the 3B2S model is able to account for the biphasic dependence of unitary conductance on symmetrical [Na+] that is suggestive of multiple occupancy and the monotonic dependence of unitary current on the mole fraction of Na+ that is compatible with single or multiple occupancy. The best-fit 3B2S barrier profiles also successfully predict bi-ionic reversal potentials for Na(+)-Li+ and Na(+)-K+ in both orientations across the channel. Our experimental and modeling results reconcile the dual personality of ion permeation through Na+ channels, which can display features of single or multiple occupancy under various conditions. To a first approximation, the 3B2S model developed for this channel does not require corrections for vestibule surface charge. However, if negative surface charges of the protein do influence conduction, the conductance behavior in the limit of low [Na+] does not correspond to a Gouy-Chapman model of planar surface charge.

Animals↗
PubMed1991

Tubulovesicular structures in human and experimental Creutzfeldt-Jakob disease.

Tubulovesicular structures (TVS) have been consistently observed in brain tissue of animals with transmissible spongiform encephalopathies such as natural and experimental scrapie, bovine spongiform encephalopathy, and experimental Creutzfeldt-Jakob disease (CJD). In this communication we demonstrate for the first time the presence of TVS in natural CJD. TVS were detected in all 3 CJD specimens. However, they were rare and were found only in one or two locations per grid. They were seen in distended pre- and postsynaptic terminals and measured approximately 35 nm in diameter, and they were smaller and of higher electron density than synaptic vesicles. Their occurrence in all types of spongiform encephalopathies irrespective of the affected host and the strain of infectious agent emphasizes their biological significance.

Animals↗