73 research outputs found

    Gene up-regulation by DNA demethylation in 35S-gshI-transgenic poplars (Populus x canescens)

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    Gene expression levels of transgene 35S-gshI (γ-glutamylcysteine synthetase) cloned from E. coli, and the endogenous gene gsh1 of poplar (Populus x canescens) were upregulated by the DNA demethylating agent DHAC (5,6-dihydro-5'-azacytidine hydrochloride) (10-4 M for 7 days) in aseptic leaf discs cultures. Two 35S-gshI-transgenic (6lgl and 11ggs) and wild type (WT) poplar clones were used. The efficiency of gene upregulation was also analyzed under herbicide paraquat stress (4 x 10-7 M). Levels of gshI-mRNA and gsh1-mRNA were determined by RT-qPCR (reverse transcriptase quantitative PCR) after cDNA synthesis. For internal control, the constitutively expressed housekeeping poplar genes α-tubulin and actin were used, and the 2−HHCt method was applied for data analysis. In long term DHAC treatment (21 days), a morphogenetic response of de novo root development was observed on leaf discs in a wide concentration range of DHAC (10-8 to 10-6 M). Adventitious shoots (11ggs clone) also emerged from leaf discs after a combined treatment with DHAC (10-4 M) and paraquat (10-7 M). Shoots were dissected, rooted and transplanted in glass houses for further analyses for phytoremediation capacity. Since DNA methylation patterns are inherited (epigenetic memory), these poplar plants with increased gene expression levels of both transgene 35S-gshI and endogenous gene gsh1 provide novel plant sources for in situ application

    Lytic and mechanical stability of clots composed of fibrin and blood vessel wall components.

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    Background Proteases expressed in atherosclerotic plaque lesions generate collagen fragments, release glycosaminoglycans (chondroitin sulfate [CS] and dermatan sulfate [DS]) and expose extracellular matrix (ECM) proteins (e.g. decorin) at sites of fibrin formation. Objective Here we address the effect of these vessel wall components on the lysis of fibrin by the tissue plasminogen activator (tPA)/plasminogen system and on the mechanical stability of clots. Methods and results MMP-8-digested collagen fragments, isolated CS, DS, glycosylated decorin and its core protein were used to prepare mixed matrices with fibrin (additives present at a 50-fold lower mass concentration than fibrinogen). Scanning electron microscopy (SEM) showed that the presence of ECM components resulted in a coarse fibrin structure, most pronounced for glycosylated decorin causing an increase in the median fiber diameter from 85 to 187 nm. Rheological measurements indicated that these structural alterations were coupled to decreased shear resistance (1.8-fold lower shear stress needed for gel/fluid transition of the clots containing glycosylated decorin) and rigidity (reduction of the storage modulus from 54.3 to 33.2 Pa). The lytic susceptibility of the modified fibrin structures was increased. The time to 50% lysis by plasmin was reduced approximately 2-fold for all investigated ECM components (apart from the core protein of decorin which produced a moderate reduction of the lysis time by 25%), whereas fibrin-dependent plasminogen activation by tPA was inhibited by up to 30%. Conclusion ECM components compromise the chemical and mechanical stability of fibrin as a result of changes in its ultrastructure

    A detailed semiologic analysis of childhood psychogenic nonepileptic seizures

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    Purpose: Psychogenic nonepileptic seizure (PNES) is an important differential diagnostic problem in patients with or without epilepsy. There are many studies that have analyzed PNES in adults; currently, however, there is no systematic assessment of purely childhood PNES semiology. Our study based on a large pediatric video-electroencephalography (EEG) monitoring (VEM) cohort, provides a detailed analysis of childhood PNES and assesses the usability of the current classification system described in adults. Methods: Medical and video-EEG records of 568 consecutive children (younger than 18 years) who underwent video-EEG monitoring (VEM) at our hospital were reviewed. Aura, type of movement, anatomic distribution, synchrony, symmetry, eye movement, responsiveness, vocalization, hyperventilation, vegetative and emotional signs, presence of eyewitness, and duration of the event were recorded among children with the diagnosis of PNES. We also compared our data with those of earlier adult studies. Key Findings: Seventy-five archived PNES of 27 children (21 girls; age 8-18 years) were reanalyzed. Nine children (33%) had the diagnosis of epilepsy currently or in the past. Mean age at the time of PNES onset was 11.6 (standard deviation 3.2) years. Mean duration of PNES was longer (269 s) compared to seizures of the epileptic group (83 s; p = 0.002). Eyewitnesses (mostly parents) were present in 89% of cases. Eighty percent of PNES had an abrupt start, with 68% also ending abruptly. In only 15% of events were the patients eyes closed at the beginning of the attack. Patients were unresponsive in 34%. The most frequent motor sign was tremor (25%) with the upper, rather than lower limbs more frequently involved. Pelvic thrusting was seen in only two attacks. Emotional-mostly negative-signs were observed during 32 PNES (43%). Based on Seneviratne et al.'s classification, 18 events (24%) were classified as rhythmic motor PNES, only half the frequency of that previously described in adults. No hypermotor PNES was found. The frequency of complex motor PNES (13%) and mixed PNES (4%) showed similar frequency in children as in adults. Dialeptic PNES was found more frequently among younger children. All PNES belonged to the same semiologic type in 23 patients (85%). Significance: Because homogeneity of PNES within a patient was high in the pediatric population, we found it useful to classify PNES into different semiologic categories. Dialeptic PNES seems to be more frequent among younger children. Tremor is the most frequent motor sign and usually accompanied by preserved responsiveness in childhood. Negative emotion is commonly seen in pediatric PNES, but pelvic thrusting is a rare phenomenon. We, therefore, suggest a modification of the present classification system in which PNES with motor activity is divided into minor and major motor PNES, and the latter group is subdivided into synchron rhythmic motor and asynchron motor PNES. We believe that our study, a detailed analysis on the semiology and classification of purely childhood PNES might assist the early and precise diagnosis of nonepileptic paroxysmal events

    FHR-1 binds to C-reactive protein and enhances rather than inhibits complement activation

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    Factor H (FH)-related protein 1 (FHR-1) is one of the five human factor H-related proteins, which share sequence and structural homology with the alternative pathway complement inhibitor FH. Genetic studies on disease associations and functional analyses indicate that FHR-1 enhances complement activation by co mpetitive inhibition of FH binding to some surfaces and immune proteins. We have recen tly shown that FHR-1 binds to pentraxin 3. Here, our aim was to investigate whether FH R-1 binds to another pentraxin, C-reactive protein (CRP), analyze the functional relevance of this interaction and study the role of FHR- 1 in complement activation and regulation. FHR- 1 did not bind to native, pentameric CRP but it bound strongly to monomeric CRP via its C-term inal domains. FHR-1 at high concentration competed with FH for CRP binding, indicating possible complement de -regulation also on this ligand. FHR-1 did not inhibi t regulation of solid phase C3 convertase by FH and did not inhibit terminal complement complex forma tion induced by zymosan. On the contrary, by binding C3b, FHR-1 allowed C3 convertase form ation and thereby enhanced complement activation. FHR-1/CRP interacti ons increased complement activ ation via the classical and alternative pathways on surfaces such as th e extracellular matrix and necrotic cells. Altogether, these results identify CRP as a lig and for FHR-1 and suggest that FHR-1 enhances rather than inhibits complement activation, wh ich may explain the protective effect of FHR-1 deficiency in age-related macular degeneration

    Prevalence, significance and predictive value of antiphospholipid antibodies in Crohn’s disease

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    AIM: To assess the prevalence and stability of different antiphospholipid antibodies (APLAs) and their association with disease phenotype and progression in inflammatory bowel diseases (IBD) patients. METHODS: About 458 consecutive patients [Crohn's disease (CD): 271 and ulcerative colitis (UC): 187] were enrolled into a follow-up cohort study in a tertiary IBD referral center in Hungary. Detailed clinical phenotypes were determined at enrollment by reviewing the patients' medical charts. Disease activity, medical treatment and data about evolvement of complications or surgical interventions were determined prospectively during the follow-up. Disease course (development f complicated disease phenotype and need for surgery), occurrence of thrombotic events, actual state of disease activity according to clinical, laboratory and endoscopic scores and accurate treatment regime were recorded during the follow-up, (median, 57.4 and 61.6 mo for CD and UC). Sera of IBD patients and 103 healthy controls (HC) were tested on individual anti-β2-Glycoprotein-I (anti-β2-GPI IgA/M/G), anti-cardiolipin (ACA IgA/M/G) and anti-phosphatidylserine/prothrombin (anti-PS/PT IgA/M/G) antibodies and also anti-Saccharomyces cerevisiae antibodies (ASCA IgA/G) by enzyme-linked immunosorbent assay (ELISA). In a subgroup of CD (n = 198) and UC patients (n = 103), obtaining consecutive samples over various arbitrary time-points during the disease course, we evaluated the intraindividual stability of the APLA status. Additionally, we provide an overview of studies, performed so far, in which significance of APLAs in IBD were assessed. RESULTS: Patients with CD had significantly higher prevalence of both ACA (23.4%) and anti-PS/PT (20.4%) antibodies than UC (4.8%, P < 0.0001 and 10.2%, P = 0.004) and HC (2.9%, P < 0.0001 and 15.5%, P = NS). No difference was found for the prevalence of anti-β2-GPI between different groups (7.2%-9.7%). In CD, no association was found between APLA and ASCA status of the patients. Occurrence of anti-β2-GPI, ACA and anti-PS/PT was not different between the group of patients with active vs inactive disease state according to appropriate clinical, laboratory and endoscopic scores in CD as well as in UC patients. All subtypes of anti-β2-GPI and ACA IgM status were found to be very stable over time, in contrast ACA IgG and even more ACA IgA status showed significant intraindividual changes. Changes in antibody status were more remarkable in CD than UC (ACA IgA: 49.9% vs 23.3% and ACA IgG: 21.2% vs 5.8%). Interestingly, 59.1% and 30.1% of CD patients who received anti-TNF therapy showed significant negative to positive changes in ACA IgA and IgG antibody status respectively. APLA status was not associated with the clinical phenotype at diagnosis or during follow-up, medical therapy, or thrombotic events and it was not associated with the probability of developing complicated disease phenotype or surgery in a Kaplan-Meier analysis. CONCLUSION: The present study demonstrated enhanced formation of APLAs in CD patients. However, presence of different APLAs were not associated with the clinical phenotype or disease course
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