117 research outputs found

    Feasibility of a multidimensional home-based exercise programme for the elderly with structured support given by the general practitioner's surgery: Study protocol of a single arm trial preparing an RCT [ISRCTN58562962]

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    <p>Abstract</p> <p>Background</p> <p>Physical activity programmes can help to prevent functional decline in the elderly. Until now, such programmes use to target either on healthy community-dwelling seniors or on elderly living in special residences or care institutions. Sedentary or frail people, however, are difficult to reach when they live in their own homes. The general practitioner's (GP) practice offers a unique opportunity to acquire these people for participation in activity programmes. We conceptualised a multidimensional home-based exercise programme that shall be delivered to the target group through cooperation between GPs and exercise therapists. In order to prepare a randomised controlled trial (RCT), a feasibility study is being conducted.</p> <p>Methods</p> <p>The study is designed as a single arm interventional trial. We plan to recruit 90 patients aged 70 years and above through their GPs. The intervention lasts 12 weeks and consists of physical activity counselling, a home-exercise programme, and exercise consultations provided by an exercise therapist in the GP's practice and via telephone. The exercise programme consists of two main components: 1. a combination of home-exercises to improve strength, flexibility and balance, 2. walking for exercise to improve aerobic capacity. Primary outcome measures are: appraisal by GP, undesirable events, drop-outs, adherence. Secondary outcome measures are: effects (a. motor tests: timed-up-and-go, chair rising, grip strength, tandem stand, tandem walk, sit-and-reach; b. telephone interview: PRISCUS-Physical Activity Questionnaire, Short Form-8 Health Survey, three month recall of frequency of falls, Falls Efficacy Scale), appraisal by participant, exercise performance, focus group discussion. Data analyses will focus on: 1. decision-making concerning the conduction of a RCT, 2. estimation of the effects of the programme, detection of shortcomings and identification of subgroups with contrary results, 3. feedback to participants and to GPs.</p> <p>Conclusion</p> <p>A new cooperation between GPs and exercise therapists to approach community-dwelling seniors and to deliver a home-exercise programme is object of research with regard to feasibility and acceptance. In case of success, an RCT should examine the effects of the programme. A future implementation within primary medical care may take advantage from the flexibility of the programme.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN58562962.</p

    Formation of the Food Vacuole in Plasmodium falciparum: A Potential Role for the 19 kDa Fragment of Merozoite Surface Protein 1 (MSP119)

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    Plasmodium falciparum Merozoite Surface Protein 1 (MSP1) is synthesized during schizogony as a 195-kDa precursor that is processed into four fragments on the parasite surface. Following a second proteolytic cleavage during merozoite invasion of the red blood cell, most of the protein is shed from the surface except for the C-terminal 19-kDa fragment (MSP119), which is still attached to the merozoite via its GPI-anchor. We have examined the fate of MSP119 during the parasite's subsequent intracellular development using immunochemical analysis of metabolically labeled MSP119, fluorescence imaging, and immuno-electronmicroscopy. Our data show that MSP119 remains intact and persists to the end of the intracellular cycle. This protein is the first marker for the biogenesis of the food vacuole; it is rapidly endocytosed into small vacuoles in the ring stage, which coalesce to form the single food vacuole containing hemozoin, and persists into the discarded residual body. The food vacuole is marked by the presence of both MSP119 and the chloroquine resistance transporter (CRT) as components of the vacuolar membrane. Newly synthesized MSP1 is excluded from the vacuole. This behavior indicates that MSP119 does not simply follow a classical lysosome-like clearance pathway, instead, it may play a significant role in the biogenesis and function of the food vacuole throughout the intra-erythrocytic phase

    A principal target of human immunity to malaria identified by molecular population genetic and immunological analyses

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    New strategies are required to identify the most important targets of protective immunity in complex eukaryotic pathogens. Natural selection maintains allelic variation in some antigens of the malaria parasite Plasmodium falciparum (1–3). Analysis of allele frequency distributions could identify the loci under most intense selection (4–7). The merozoite surface protein 1 (Msp1) is the most-abundant surface component on the erythrocyte-invading stage of P. falciparum (8–10). Immunization with whole Msp1 has protected monkeys completely against homologous (11) and partially against non-homologous (12) parasite strains. The singlecopy msp1 gene, of about 5 kilobases, has highly divergent alleles (13) with stable frequencies in endemic populations (14,15). To identify the region of msp1 under strongest selection to maintain alleles within populations, we studied multiple intragenic sequence loci in populations in different regions of Africa and Southeast Asia. On both continents, the locus with the lowest inter-population variance in allele frequencies was block 2, indicating selection in this part of the gene. To test the hypothesis of immune selection, we undertook a large prospective longitudinal cohort study. This demonstrated that serum IgG antibodies against each of the two most frequent allelic types of block 2 of the protein were strongly associated with protection from P. falciparum malaria

    Short and long term outcome of bilateral pallidal stimulation in chorea-acanthocytosis

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    BACKGROUND: Chorea-acanthocytosis (ChAc) is a neuroacanthocytosis syndrome presenting with severe movement disorders poorly responsive to drug therapy. Case reports suggest that bilateral deep brain stimulation (DBS) of the ventro-postero-lateral internal globus pallidus (GPi) may benefit these patients. To explore this issue, the present multicentre (n=12) retrospective study collected the short and long term outcome of 15 patients who underwent DBS. METHODS: Data were collected in a standardized way 2-6 months preoperatively, 1-5 months (early) and 6 months or more (late) after surgery at the last follow-up visit (mean follow-up: 29.5 months). RESULTS: Motor severity, assessed by the Unified Huntington's Disease Rating Scale-Motor Score, UHDRS-MS), was significantly reduced at both early and late post-surgery time points (mean improvement 54.3% and 44.1%, respectively). Functional capacity (UHDRS-Functional Capacity Score) was also significantly improved at both post-surgery time points (mean 75.5% and 73.3%, respectively), whereas incapacity (UHDRS-Independence Score) improvement reached significance at early post-surgery only (mean 37.3%). Long term significant improvement of motor symptom severity (≥ 20 % from baseline) was observed in 61.5 % of the patients. Chorea and dystonia improved, whereas effects on dysarthria and swallowing were variable. Parkinsonism did not improve. Linear regression analysis showed that preoperative motor severity predicted motor improvement at both post-surgery time points. The most serious adverse event was device infection and cerebral abscess, and one patient died suddenly of unclear cause, 4 years after surgery. CONCLUSION: This study shows that bilateral DBS of the GPi effectively reduces the severity of drug-resistant hyperkinetic movement disorders such as present in ChAc

    Identification of novel pathways involved in the pathogenesis of human adamantinomatous craniopharyngioma

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    Activating mutations in the gene encoding β-catenin have been identified in the paediatric form of human craniopharyngioma (adamantinomatous craniopharyngioma, ACP), a histologically benign but aggressive pituitary tumour accounting for up to 10% of paediatric intracranial tumours. Recently, we generated an ACP mouse model and revealed that, as in human ACP, nucleocytoplasmic accumulation of β-catenin (β-catnc) and over-activation of the Wnt/β-catenin pathway occurs only in a very small proportion of cells, which form clusters. Here, combining mouse genetics, fluorescence labelling and flow-sorting techniques, we have isolated these cells from tumorigenic mouse pituitaries and shown that the β-catnc cells are enriched for colony-forming cells when cultured in stem cell-promoting media, and have longer telomeres, indicating shared properties with normal pituitary progenitors/stem cells (PSCs). Global gene profiling analysis has revealed that these β-catnc cells express high levels of secreted mitogenic signals, such as members of the SHH, BMP and FGF family, in addition to several chemokines and their receptors, suggesting an important autocrine/paracrine role of these cells in the pathogenesis of ACP and a reciprocal communication with their environment. Finally, we highlight the clinical relevance of these findings by showing that these pathways are also up-regulated in the β-catnc cell clusters identified in human ACP. As well as providing further support to the concept that pituitary stem cells may play an important role in the oncogenesis of human ACP, our data reveal novel disease biomarkers and potential pharmacological targets for the treatment of these devastating childhood tumours.Electronic supplementary materialThe online version of this article (doi:10.1007/s00401-012-0957-9) contains supplementary material, which is available to authorized users

    Antibody Responses to a Novel Plasmodium falciparum Merozoite Surface Protein Vaccine Correlate with Protection against Experimental Malaria Infection in Aotus Monkeys

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    The Block 2 region of the merozoite surface protein-1 (MSP-1) of Plasmodium falciparum has been identified as a target of protective immunity by a combination of seroepidemiology and parasite population genetics. Immunogenicity studies in small animals and Aotus monkeys were used to determine the efficacy of recombinant antigens derived from this region of MSP-1 as a potential vaccine antigen. Aotus lemurinus griseimembra monkeys were immunized three times with a recombinant antigen derived from the Block 2 region of MSP-1 of the monkey-adapted challenge strain, FVO of Plasmodium falciparum, using an adjuvant suitable for use in humans. Immunofluorescent antibody assays (IFA) against erythrocytes infected with P. falciparum using sera from the immunized monkeys showed that the MSP-1 Block 2 antigen induced significant antibody responses to whole malaria parasites. MSP-1 Block 2 antigen-specific enzyme-linked immunosorbent assays (ELISA) showed no significant differences in antibody titers between immunized animals. Immunized animals were challenged with the virulent P. falciparum FVO isolate and monitored for 21 days. Two out of four immunized animals were able to control their parasitaemia during the follow-up period, whereas two out of two controls developed fulminating parasitemia. Parasite-specific serum antibody titers measured by IFA were four-fold higher in protected animals than in unprotected animals. In addition, peptide-based epitope mapping of serum antibodies from immunized Aotus showed distinct differences in epitope specificities between protected and unprotected animals
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