206 research outputs found
Implementation and evaluation of a fall risk screening strategy among frail older adults for the primary care setting:A study protocol
Background: Falls are an increasing problem among older people. There are several evidence-based interventions available to prevent falls. However, these are not always well implemented in the primary care setting. General practitioners (GPs) are often the first point of contact for health issues, making them the designated professionals for providing falls prevention. Because GPs are often unaware which patients have a high fall risk and patients themselves do not always know they have a high fall risk, this study aims to evaluate the implementation of a targeted fall risk screening strategy among independently living, frail older people in the primary care setting. Materials and methods: The targeted fall risk screening strategy used in this study consists of tools for screening high fall risk and for identifying the underlying cause(s) of the high fall risk, an accredited training course in falls prevention for professionals, and service provision by certified physio- and exercise therapists who are able to offer evidence-based falls prevention interventions. This targeted fall risk screening strategy will be implemented in the primary care setting and evaluated at the level of the GP practice and at the level of the patient by using the RE-AIM model of Glasgow et al. In a pre-posttest design, data will be collected of the total number of frail older people who are screened, referred and enrolled for fall-preventive care. Furthermore, barriers and facilitators of the implementation of the fall risk screening strategy will be identified by conducting focus groups and interviews with the care providers and frail older patients. Additionally, the influence of the falls prevention interventions on frail older patients will be evaluated by using a pre-posttest design with a 12-month follow-up period during which data are collected regarding patients' stability, mobility, strength, balance, self-efficacy, health status, and daily activities. Study Registration: This study is approved by the Medical Ethics Committee Brabant, the Netherlands (NL61582.028.17/ P1732) and registered at the Netherlands Trial Register, NL7917
Topical rapamycin as a treatment for fibrofolliculomas in Birt-Hogg-Dubé syndrome:a double-blind placebo-controlled randomized split-face trial
Background: Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant disorder characterised by the occurrence of benign, mostly facial, skin tumours called fibrofolliculomas, multiple lung cysts, spontaneous pneumothorax and an increased renal cancer risk. Current treatments for fibrofolliculomas have high rates of recurrence and carry a risk of complications. It would be desirable to have a treatment that could prevent fibrofolliculomas from growing. Animal models of BHD have previously shown deregulation of mammalian target of rapamycin (mTOR). Topical use of the mTOR inhibitor rapamycin is an effective treatment for the skin tumours (angiofibromas) in tuberous sclerosis complex, which is also characterised by mTOR deregulation. In this study we aimed to determine if topical rapamycin is also an effective treatment for fibrofolliculomas in BHD. Methods: We performed a double blinded, randomised, facial left-right controlled trial of topical rapamycin 0.1% versus placebo in 19 BHD patients. Trial duration was 6 months. The primary outcome was cosmetic improvement as measured by doctors and patients. Changes in fibrofolliculoma number and size were also measured, as was occurrence of side effects. Results: No change in cosmetic status of fibrofolliculomas was reported in the majority of cases for the rapamycin treated (79% by doctors, 53% by patients) as well as the placebo treated facial sides (both 74%). No significant differences between rapamycin and placebo treated facial halves were observed (p = 1.000 for doctors opinion, p = 0.344 for patients opinion). No significant difference in fibrofolliculoma number or change in size of the fibrofolliculomas was seen after 6 months. Side effects occurred more often after rapamycin treatment (68% of patients) than after placebo (58% of patients; p = 0.625). A burning sensation, erythema, itching and dryness were most frequently reported. Conclusions: This study provides no evidence that treatment of fibrofolliculomas with topical rapamycin in BHD results in cosmetic improvement. Trial Registration: ClinicalTrials.gov NCT00928798</p
Analysis of congenital disorder of glycosylation-Id in a yeast model system shows diverse site-specific under-glycosylation of glycoproteins
Asparagine-linked glycosylation is a common post translational modification of proteins in eukaryotes. Mutations in the human ALG3 gene cause changed levels and altered glycan structures on mature glycoproteins and are the cause of a severe congenital disorder of glycosylation (CDG-Id). Diverse glycoproteins are also under-glycosylated in Saccharomyces cerevisae alg3 mutants. Here we analyzed site-specific glycosylation occupancy in this yeast model system using peptide-N-glycosidase F to label glycosylation sites with an asparagine-aspartate conversion that creates a new endoproteinase AspN cleavage site, followed by proteolytic digestion, and detection of peptides and glycopeptides by LC-ESI-MS/MS. We used this analytical method to identify and measure site specific glycosylation occupancy in alg3 mutant and wild type yeast strains. We found decreased site specific N-glycosylation occupancy in the alg3 knockout strain preferentially at Asn-Xaa-Ser sequences located in secondary structural elements, features previously associated with poor glycosylation efficiency. Furthermore, we identified 26 previously experimentally unverified glycosylation sites. Our results provide insights into the underlying mechanisms of disease in CDG-Id, and our methodology will be useful in site specific glycosylation analysis in many model systems and clinical applications
Treatment seeking for alcohol and drug use disorders by immigrants to the Netherlands: Retrospective, population-based, cohort study
Background We compared risks of first contact with services for an alcohol use disorder (AUD) or drug use disorder (DUD) between the largest immigrant groups to the Netherlands and Dutch nationals. We tested the hypothesis that the ethnic pattern for DUD is similar to the previously demonstrated pattern for schizophrenia. Methods Retrospective, population-based cohort study of First Admissions to Dutch psychiatric hospitals during the period 1990-1996 (national data) and First Contacts with inpatient or outpatient centres in Rotterdam for treatment of AUD or DUD during the period 1992-2001 (Rotterdam data). Results In both datasets the risk of service contact for AUD was significantly lower in immigrants from Surinam, Turkey and Morocco than in Dutch nationals. The risk was lower or moderately higher in immigrants from western countries. Analysis of the national data showed that, compared with Dutch males, the risk of first hospital admission for DUD was higher for male immigrants from the Dutch Antilles (RR = 4.6; 95% CI: 4.0-5.3), Surinam (RR = 4.3; 3.94.7) and Morocco (RR = 23; 2.0-2.6), but not for male immigrants from Turkey (RR = 0.9; 0.7-1.1). A similar pattern was found with the Rotterdam data. Female immigrants from Surinam and the Dutch Antilles had a higher risk for DUD according to the national data, but a lower risk according to the Rotterdam data. Female immigrants from Turkey and Morocco had a lower risk (both datasets). Immigrants from western countries had a higher risk for DUD, but many had developed the disorder before emigrating. Conclusion Those immigrant groups in the Netherlands that are at increased risk of schizophrenia appear also at increased risk of developing DUD, but not AUD
Design paper: The CapOpus trial: A randomized, parallel-group, observer-blinded clinical trial of specialized addiction treatment versus treatment as usual for young patients with cannabis abuse and psychosis
Differential effects of human and plant N-acetylglucosaminyltransferase I (GnTI) in plants
In plants and animals, the first step in complex type N-glycan formation on glycoproteins is catalyzed by N-acetylglucosaminyltransferase I (GnTI). We show that the cgl1-1 mutant of Arabidopsis, which lacks GnTI activity, is fully complemented by YFP-labeled plant AtGnTI, but only partially complemented by YFP-labeled human HuGnTI and that this is due to post-transcriptional events. In contrast to AtGnTI-YFP, only low levels of HuGnTI-YFP protein was detected in transgenic plants. In protoplast co-transfection experiments all GnTI-YFP fusion proteins co-localized with a Golgi marker protein, but only limited co-localization of AtGnTI and HuGnTI in the same plant protoplast. The partial alternative targeting of HuGnTI in plant protoplasts was alleviated by exchanging the membrane-anchor domain with that of AtGnTI, but in stably transformed cgl1-1 plants this chimeric GnTI still did not lead to full complementation of the cgl1-1 phenotype. Combined, the results indicate that activity of HuGnTI in plants is limited by a combination of reduced protein stability, alternative protein targeting and possibly to some extend to lower enzymatic performance of the catalytic domain in the plant biochemical environment
Delta-9-tetrahydrocannabinol, neural oscillations above 20 Hz and induced acute psychosis
Rationale: An acute challenge with delta-9-tetrahydrocannabinol (THC) can induce psychotic symptoms including delusions. High electroencephalography (EEG) frequencies, above 20 Hz, have previously been implicated in psychosis and schizophrenia. Objectives: The objective of this study is to determine the effect of intravenous THC compared to placebo on high-frequency EEG. Methods: A double-blind cross-over study design was used. In the resting state, the high-beta to low-gamma magnitude (21–45 Hz) was investigated (n=13 pairs+4 THC only). Also, the event-related synchronisation (ERS) of motor-associated high gamma was studied using a self-paced button press task (n=15). Results: In the resting state, there was a significant condition × frequency interaction (p=0.00017), consisting of a shift towards higher frequencies under THC conditions (reduced high beta [21–27 Hz] and increased low gamma [27–45 Hz]). There was also a condition × frequency × location interaction (p=0.006), such that the reduction in 21–27-Hz magnitude tended to be more prominent in anterior regions, whilst posterior areas tended to show greater 27–45-Hz increases. This effect was correlated with positive symptoms, as assessed on the Positive and Negative Syndrome Scale (PANSS) (r=0.429, p=0.042). In the motor task, there was a main effect of THC to increase 65–130-Hz ERS (p=0.035) over contra-lateral sensorimotor areas, which was driven by increased magnitude in the higher, 85–130-Hz band (p=0.02) and not the 65–85-Hz band. Conclusions: The THC-induced shift to faster gamma oscillations may represent an over-activation of the cortex, possibly related to saliency misattribution in the delusional state
Engineering Yarrowia lipolytica to Produce Glycoproteins Homogeneously Modified with the Universal Man3GlcNAc2 N-Glycan Core
Yarrowia lipolytica is a dimorphic yeast that efficiently secretes various heterologous proteins and is classified as “generally recognized as safe.” Therefore, it is an attractive protein production host. However, yeasts modify glycoproteins with non-human high mannose-type N-glycans. These structures reduce the protein half-life in vivo and can be immunogenic in man. Here, we describe how we genetically engineered N-glycan biosynthesis in Yarrowia lipolytica so that it produces Man3GlcNAc2 structures on its glycoproteins. We obtained unprecedented levels of homogeneity of this glycanstructure. This is the ideal starting point for building human-like sugars. Disruption of the ALG3 gene resulted in modification of proteins mainly with Man5GlcNAc2 and GlcMan5GlcNAc2 glycans, and to a lesser extent with Glc2Man5GlcNAc2 glycans. To avoid underoccupancy of glycosylation sites, we concomitantly overexpressed ALG6. We also explored several approaches to remove the terminal glucose residues, which hamper further humanization of N-glycosylation; overexpression of the heterodimeric Apergillus niger glucosidase II proved to be the most effective approach. Finally, we overexpressed an α-1,2-mannosidase to obtain Man3GlcNAc2 structures, which are substrates for the synthesis of complex-type glycans. The final Yarrowia lipolytica strain produces proteins glycosylated with the trimannosyl core N-glycan (Man3GlcNAc2), which is the common core of all complex-type N-glycans. All these glycans can be constructed on the obtained trimannosyl N-glycan using either in vivo or in vitro modification with the appropriate glycosyltransferases. The results demonstrate the high potential of Yarrowia lipolytica to be developed as an efficient expression system for the production of glycoproteins with humanized glycans
Psychosis risk as a function of age at onset: A comparison between early- and late-onset psychosis in a general population sample
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