970 resultados para Celiac Disease -- immunology


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Genetic susceptibility to juvenile idiopathic arthritis (JIA) was studied in the genetically homogeneous Finnish population by collecting families with two or three patients affected by this disease from cases seen in the Rheumatism Foundation Hospital. The number of families ranged in different studies from 37 to 45 and the total number of patients with JIA, from among whom these cases were derived, was 2 000 to 2 300. Characteristics of the disease in affected siblings in Finland were compared with a population-based series and with a sibling series from the United States. A thorough clinical and ophthalmological examination was made of all affected patients belonging to sibpair series. Information on the occurrence of chronic rheumatic diseases in parents was collected by questionnaire and diagnoses were confirmed from hospital records. All patients, their parents and most of the healthy sibs were typed for human leukocyte antigen (HLA) alleles in loci A, C, B, DR and DQ. The HLA allele distribution of the cases was compared with corresponding data from Finnish bone marrow donors. The genetic component in JIA was found to be more significant than previously believed. A concordance rate of 25% for a disease with a population prevalence of 1 per 1000 implied a relative risk of 250 for a monozygotic (MZ) twin. An estimate for the sibling risk of an affected individual was about 15- to 20-fold. The disease was basically similar in familial and sporadic cases; the mean age at disease onset was however lower in familial cases, (4.8 years vs 7.4 years). Three sibpairs (3.4 expected) were concordant for the presence of asymptomatic uveitis. Uveitis would thus not appear to have any genetic component of its own, separate from the genetic basis of JIA. Four of the parents had JIA (0.2 cases expected), four had a type of rheumatoid factor-negative arthritis similar to that seen in juvenile patients but commencing in adulthood, and one had spondyloarthropathy (SPA). These findings provide additional support for the conception of a genetic predisposition to JIA and suggest the existence of a new disease entity, JIA of adult onset. Both the linkage analysis of the affected sibpairs and the association analysis of nuclear families provided overwhelming evidence of a major contribution of HLA to the genetic susceptibility to JIA. The association analysis in the Finnish population confirmed that the most significant associations prevailed for DRB1*0801, DQB1*0402, as expected from previous observations, and indicated the independent role of Cw*0401.

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Heart failure is a common and highly challenging medical disorder. The progressive increase of elderly population is expected to further reflect in heart failure incidence. Recent progress in cell transplantation therapy has provided a conceptual alternative for treatment of heart failure. Despite improved medical treatment and operative possibilities, end-stage coronary artery disease present a great medical challenge. It has been estimated that therapeutic angiogenesis would be the next major advance in the treatment of ischaemic heart disease. Gene transfer to augment neovascularization could be beneficial for such patients. We employed a porcine model to evaluate the angiogenic effect of vascular endothelial growth factor (VEGF)-C gene transfer. Ameroid-generated myocardial ischemia was produced and adenovirus encoding (ad)VEGF-C or β-galactosidase (LacZ) gene therapy was given intramyocardially during progressive coronary stenosis. Angiography, positron emission tomography (PET), single photon emission computed tomography (SPECT) and histology evidenced beneficial affects of the adVEGF-C gene transfer compared to adLacZ. The myocardial deterioration during progressive coronary stenosis seen in the control group was restrained in the treatment group. We observed an uneven occlusion rate of the coronary vessels with Ameroid constrictor. We developed a simple methodological improvement of Ameroid model by ligating of the Ameroid–stenosed coronary vessel. Improvement of the model was seen by a more reliable occlusion rate of the vessel concerned and a formation of a rather constant myocardial infarction. We assessed the spontaneous healing of the left ventricle (LV) in this new model by SPECT, PET, MRI, and angiography. Significant spontaneous improvement of myocardial perfusion and function was seen as well as diminishment of scar volume. Histologically more microvessels were seen in the border area of the lesion. Double staining of the myocytes in mitosis indicated more cardiomyocyte regeneration at the remote area of the lesion. The potential of autologous myoblast transplantation after ischaemia and infarction of porcine heart was evaluated. After ligation of stenosed coronary artery, autologous myoblast transplantation or control medium was directly injected into the myocardium at the lesion area. Assessed by MRI, improvement of diastolic function was seen in the myoblast-transplanted animals, but not in the control animals. Systolic function remained unchanged in both groups.

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Mitochondrial diseases are caused by disturbances of the energy metabolism. The disorders range from severe childhood neurological diseases to muscle diseases of adults. Recently, mitochondrial dysfunction has also been found in Parkinson s disease, diabetes, certain types of cancer and premature aging. Mitochondria are the power plants of the cell but they also participate in the regulation of cell growth, signaling and cell death. Mitochondria have their own genetic material, mtDNA, which contains the genetic instructions for cellular respiration. Single cell may host thousands of mitochondria and several mtDNA molecules may reside inside single mitochondrion. All proteins needed for mtDNA maintenance are, however, encoded by the nuclear genome, and therefore, mutations of the corresponding genes can also cause mitochondrial disease. We have here studied the function of mitochondrial helicase Twinkle. Our research group has previously identified nuclear Twinkle gene mutations underlying an inherited adult-onset disorder, progressive external ophthalmoplegia (PEO). Characteristic for the PEO disease is the accumulation of multiple mtDNA deletions in tissues such as the muscle and brain. In this study, we have shown that Twinkle helicase is essential for mtDNA maintenance and that it is capable of regulating mtDNA copy number. Our results support the role of Twinkle as the mtDNA replication helicase. No cure is available for mitochondrial disease. Good disease models are needed for studies of the cause of disease and its progression and for treatment trials. Such disease model, which replicates the key features of the PEO disease, has been generated in this study. The model allows for careful inspection of how Twinkle mutations lead to mtDNA deletions and further causes the PEO disease. This model will be utilized in a range of studies addressing the delay of the disease onset and progression and in subsequent treatment trials. In conclusion, in this thesis fundamental knowledge of the function of the mitochondrial helicase Twinkle was gained. In addition, the first model for adult-onset mitochondrial disease was generated.

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Objective: Glucocorticoid therapy is used worldwide to treat various inflammatory and immune conditions, including inflammatory bowel disease (IBD). In IBD, 80% of the patients obtain a positive response to the therapy; however the development of glucocorticoid-related side-effects is common. Our aim was therefore to study the possibility of optimizing glucocorticoid therapy in children and adolescents with IBD by measuring circulating glucocorticoid bioactivity (GBA) and serum glucocorticoid-responsive biomarkers in patients receiving steroid treatment for active disease. Methods: A total of sixty-nine paediatric IBD patients from the Paediatric Outpatient Clinics of the University Hospitals of Helsinki and Tampere participated in the studies. Control patients included 101 non-IBD patients and 41 disease controls in remission. In patients with active disease, blood samples were withdrawn before the glucocorticoid therapy was started, at 2-4 weeks after the initiation of the steroid and at 1-month intervals thereafter. Clinical response to glucocorticoid treatment and the development of steroid adverse events was carefully registered. GBA was analyzed with a COS-1 cell bioassay. The measured glucocorticoid therapy-responsive biomarkers included adipocyte-derived adiponectin and leptin, bone turnover-related collagen markers amino-terminal type I procollagen propeptide (PINP) and carboxyterminal telopeptide of type I collagen (ICTP) as well as insulin-like growth factor 1 (IGF-1) and sex hormone-binding globulin (SHBG), and inflammatory marker high-sensitivity C-reactive protein (hs-CRP). Results: The most promising marker for glucocorticoid sensitivity was serum adiponectin that associated with steroid therapy–related adverse events. Serum leptin indicated a similar trend. In contrast, circulating GBA rose in all subjects receiving glucocorticoid treatment but did not associate with the clinical response to steroids or with glucocorticoid therapy-related side-effects. Of notice, young patients (<10 years) showed similar GBA levels than older patients, despite receiving higher weight-adjusted doses of glucocorticoid. Markers of bone formation were lower in children with active IBD than in the control patients, probably reflecting the suppressive effect of the active inflammation. The onset of the glucocorticoid therapy further suppressed bone turnover. Inflammatory marker hs-CRP decreased readily after the initiation of the steroid, however the decrease did not associate with the clinical response to glucocorticoids. Conclusions: This is the first study to show that adipocyte-derived adiponectin associates with steroid therapy-induced side-effects. Further studies are needed, but it is possible that the adiponectin measurement could aid the recognition of glucocorticoid-sensitive patients in the future. GBA and the other markers reflecting glucocorticoid activity in different tissues changed during the treatment, however their change did not correlate with the therapeutic response to steroids or with the development of glucocorticoid-related side effects and therefore cannot guide the therapy in these patients. Studies such as as the present one that combine clinical data with newly developed biomolecular technology are needed to step-by-step build a general picture of the glucocorticoid actions in different tissues.

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Background The leading causes of morbidity and mortality for people in high-income countries living with HIV are now non-AIDS malignancies, cardiovascular disease and other non-communicable diseases associated with ageing. This protocol describes the trial of HealthMap, a model of care for people with HIV (PWHIV) that includes use of an interactive shared health record and self-management support. The aims of the HealthMap trial are to evaluate engagement of PWHIV and healthcare providers with the model, and its effectiveness for reducing coronary heart disease risk, enhancing self-management, and improving mental health and quality of life of PWHIV. Methods/Design The study is a two-arm cluster randomised trial involving HIV clinical sites in several states in Australia. Doctors will be randomised to the HealthMap model (immediate arm) or to proceed with usual care (deferred arm). People with HIV whose doctors are randomised to the immediate arm receive 1) new opportunities to discuss their health status and goals with their HIV doctor using a HealthMap shared health record; 2) access to their own health record from home; 3) access to health coaching delivered by telephone and online; and 4) access to a peer moderated online group chat programme. Data will be collected from participating PWHIV (n = 710) at baseline, 6 months, and 12 months and from participating doctors (n = 60) at baseline and 12 months. The control arm will be offered the HealthMap intervention at the end of the trial. The primary study outcomes, measured at 12 months, are 1) 10-year risk of non-fatal acute myocardial infarction or coronary heart disease death as estimated by a Framingham Heart Study risk equation; and 2) Positive and Active Engagement in Life Scale from the Health Education Impact Questionnaire (heiQ). Discussion The study will determine the viability and utility of a novel technology-supported model of care for maintaining the health and wellbeing of people with HIV. If shown to be effective, the HealthMap model may provide a generalisable, scalable and sustainable system for supporting the care needs of people with HIV, addressing issues of equity of access. Trial registration Universal Trial Number (UTN) U111111506489; ClinicalTrial.gov Id NCT02178930 submitted 29 June 2014

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Parkinson s disease (PD) is a neurodegenerative disorder associated with a progressive loss of dopaminergic neurons of the substantia nigra (SN). Current therapies of PD do not stop the progression of the disease and the efficacy of these treatments wanes over time. Neurotrophic factors are naturally occurring proteins promoting the survival and differentiation of neurons and the maintenance of neuronal contacts. Neurotrophic factors are attractive candidates for neuroprotective or even neurorestorative treatment of PD. Thus, searching for and characterizing trophic factors are highly important approaches to degenerative diseases. CDNF (cerebral dopamine neurotrophic factor) and MANF (mesencephalic astrocyte-derived neurotrophic factor) are secreted proteins that constitute a novel, evolutionarily conserved neurotrophic factor family expressed in vertebrates and invertebrates. The present study investigated the neuroprotective and restorative effects of human CDNF and MANF in rats with unilateral partial lesion of dopamine neurons by 6-hydroxydopamine (6-OHDA) using both behavioral (amphetamine-induced rotation) and immunohistochemical analyses. We also investigated the distribution and transportation profiles of intrastriatally injected CDNF and MANF in rats. Intrastriatal CDNF and MANF protected nigrostriatal dopaminergic neurons when administered six hours before or four weeks after the neurotoxin 6-OHDA. More importantly, the function of the lesioned nigrostriatal dopaminergic system was partially restored even when the neurotrophic factors were administered four weeks after 6-OHDA. A 14-day continuous infusion of CDNF but not of MANF restored the function of the midbrain neural circuits controlling movement when initiated two weeks after unilateral injection of 6-OHDA. Continuous infusion of CDNF also protected dopaminergic TH-positive cell bodies from toxin-induced degeneration in the substantia nigra pars compacta (SNpc) and fibers in the striatum. When injected into the striatum, CDNF and GDNF had similar transportation profiles from the striatum to the SNpc; thus CDNF may act via the same nerve tracts as GDNF. Intrastriatal MANF was transported to cortical areas which may reflect a mechanism of neurorestorative action that is different from that of CDNF and GDNF. CDNF and MANF were also shown to distribute more readily than GDNF. In conclusion, CDNF and MANF are potential therapeutic proteins for the treatment of PD.

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Part I: Parkinson’s disease is a slowly progressive neurodegenerative disorder in which particularly the dopaminergic neurons of the substantia nigra pars compacta degenerate and die. Current conventional treatment is based on restraining symptoms but it has no effect on the progression of the disease. Gene therapy research has focused on the possibility of restoring the lost brain function by at least two means: substitution of critical enzymes needed for the synthesis of dopamine and slowing down the progression of the disease by supporting the functions of the remaining nigral dopaminergic neurons by neurotrophic factors. The striatal levels of enzymes such as tyrosine hydroxylase, dopadecarboxylase and GTP-CH1 are decreased as the disease progresses. By replacing one or all of the enzymes, dopamine levels in the striatum may be restored to normal and behavioral impairments caused by the disease may be ameliorated especially in the later stages of the disease. The neurotrophic factors glial cell derived neurotrophic factor (GDNF) and neurturin have shown to protect and restore functions of dopaminergic cell somas and terminals as well as improve behavior in animal lesion models. This therapy may be best suited at the early stages of the disease when there are more dopaminergic neurons for neurotrophic factors to reach. Viral vector-mediated gene transfer provides a tool to deliver proteins with complex structures into specific brain locations and provides long-term protein over-expression. Part II: The aim of our study was to investigate the effects of two orally dosed COMT inhibitors entacapone (10 and 30 mg/kg) and tolcapone (10 and 30 mg/kg) with a subsequent administration of a peripheral dopadecarboxylase inhibitor carbidopa (30 mg/kg) and L- dopa (30 mg/kg) on dopamine and its metabolite levels in the dorsal striatum and nucleus accumbens of freely moving rats using dual-probe in vivo microdialysis. Earlier similarly designed studies have only been conducted in the dorsal striatum. We also confirmed the result of earlier ex vivo studies regarding the effects of intraperitoneally dosed tolcapone (30 mg/kg) and entacapone (30 mg/kg) on striatal and hepatic COMT activity. The results obtained from the dorsal striatum were generally in line with earlier studies, where tolcapone tended to increase dopamine and DOPAC levels and decrease HVA levels. Entacapone tended to keep striatal dopamine and HVA levels elevated longer than in controls and also tended to elevate the levels of DOPAC. Surprisingly in the nucleus accumbens, dopamine levels after either dose of entacapone or tolcapone were not elevated. Accumbal DOPAC levels, especially in the tolcapone 30 mg/kg group, were elevated nearly to the same extent as measured in the dorsal striatum. Entacapone 10 mg/kg elevated accumbal HVA levels more than the dose of 30 mg/kg and the effect was more pronounced in the nucleus accumbens than in the dorsal striatum. This suggests that entacapone 30 mg/kg has minor central effects. Also our ex vivo study results obtained from the dorsal striatum suggest that entacapone 30 mg/kg has minor and transient central effects, even though central HVA levels were not suppressed below those of the control group in either brain area in the microdialysis study. Both entacapone and tolcapone suppressed hepatic COMT activity more than striatal COMT activity. Tolcapone was more effective than entacapone in the dorsal striatum. The differences between dopamine and its metabolite levels in the dorsal striatum and nucleus accumbens may be due to different properties of the two brain areas.

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Alternative pathway (AP) of complement can be activated on any surface, self or non-self. In atypical hemolytic uremic syndrome (aHUS) the AP regulation on self surfaces is insufficient and leads to complement attack against self-cells resulting usually in end-stage renal disease. Factor H (FH) is one of the key regulators of AP activation on the self surfaces. The domains 19 and 20 (FH19-20) are critical for the ability of FH to discriminate between C3b-opsonized self and non-self surfaces and are a hot-spot for mutations that have been described from aHUS patients. FH19-20 contains binding sites for both the C3d part of C3b and self surface polyanions that are needed for efficient C3b inactivation. To study the dysfunction of FH19-20, crystallographic structures of FH19-20 and FH19-20 in complex with C3d (FH19-20:C3d) were solved and aHUS-associated and structurally interesting point mutations were induced to FH19-20. Functional defects caused by these mutations were studied by analyzing binding of the FH19-20 mutant proteins to C3d, C3b, heparin, and mouse glomerular endothelial cells (mGEnCs). The results revealed two independent binding interfaces between FH19-20 and C3d - the FH19 site and the FH20 site. Superimposition of the FH19-20:C3d complex on the previously published C3b and FH1-4:C3b structures showed that the FH20 site on C3d is partially occluded, but the FH19 site is fully available. Furthermore, binding of FH19-20 via the FH19 site to C3b did not block binding of the functionally important FH1-4 domains and kept the FH20 site free to bind heparin or an additional C3d. Binding assays were used to show that FH20 domain can bind to heparin while FH19-20 is bound to C3b via the FH19 site, and that both the FH19 site and FH20 are necessary for recognition of non-activator surfaces. Simultaneous binding of FH19 site to C3b and FH20 to anionic self structures are the key interactions in self-surface recognition by FH and thereby enhanced avidity of FH explains how AP discriminates between self and non-self. The aHUS-associated mutations on FH19-20 were found to disrupt binding of the FH19 or FH20 site to C3d/C3b, or to disrupt binding of FH20 to heparin or mGEnC. Any of these dysfunctions leads to loss of FH avidity to C3b bearing self surfaces explaining the molecular pathogenesis of the aHUS-cases where mutations are found within FH19-20.

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The complex web of interactions between the host immune system and the pathogen determines the outcome of any infection. A computational model of this interaction network, which encodes complex interplay among host and bacterial components, forms a useful basis for improving the understanding of pathogenesis, in filling knowledge gaps and consequently to identify strategies to counter the disease. We have built an extensive model of the Mycobacterium tuberculosis host-pathogen interactome, consisting of 75 nodes corresponding to host and pathogen molecules, cells, cellular states or processes. Vaccination effects, clearance efficiencies due to drugs and growth rates have also been encoded in the model. The system is modelled as a Boolean network. Virtual deletion experiments, multiple parameter scans and analysis of the system's response to perturbations, indicate that disabling processes such as phagocytosis and phagolysosome fusion or cytokines such as TNF-alpha and IFN-gamma, greatly impaired bacterial clearance, while removing cytokines such as IL-10 alongside bacterial defence proteins such as SapM greatly favour clearance. Simulations indicate a high propensity of the pathogen to persist under different conditions.