13 research outputs found
Evaluating the causality of novel sequence variants in the prion protein gene by example
The estimation of pathogenicity and penetrance of novel prion protein gene (PRNP) variants presents significant challenges, particularly in the absence of family history, which precludes the application of Mendelian segregation. Moreover, the ambiguities of prion disease pathophysiology renders conventional in silico predictions inconclusive. Here, we describe 2 patients with rapid cognitive decline progressing to akinetic mutism and death within 10Â weeks of symptom onset, both of whom possessed the novel T201S variant in PRNP. Clinically, both satisfied diagnostic criteria for probable sporadic Creutzfeldt-Jakob disease and in one, the diagnosis was confirmed by neuropathology. While computational analyses predicted that T201S was possibly deleterious, molecular strain typing, prion protein structural considerations, and calculations leveraging large-scale population data (gnomAD) indicate that T201S is at best either of low penetrance or nonpathogenic. Thus, we illustrate the utility of harnessing multiple lines of prion disease-specific evidence in the evaluation of the T201S variant, which may be similarly applied to assess other novel variants in PRNP
Predictors of survival in progressive supranuclear palsy and multiple system atrophy: a systematic review and meta-analysis
Objective To undertake a systematic review and meta-analysis of studies that investigated prognostic factors and survival in patients with progressive supranuclear palsy (PSP) and multiple system atrophy (MSA).
Methods Publications of at least 10 patients with a likely or confirmed diagnosis of PSP or MSA were eligible for inclusion. Methodological quality was rated using a modified version of the Quality in Prognostic Studies tool. For frequently examined prognostic factors, HRs derived by univariate and multivariate analysis were pooled in separate subgroups; other results were synthesised narratively and HRs could not be reported here.
Results Thirty-seven studies presenting findings on 6193 patients (1911 PSP, 4282 MSA) fulfilled the inclusion criteria. We identified the following variables as unfavourable predictors of survival. In PSP, PSP-Richardson’s phenotype (univariate HR 2.53; 95% CI 1.69 to 3.78), early dysphagia and early cognitive symptoms. In MSA, severe dysautonomia and early development of combined autonomic and motor features but not MSA phenotype (multivariate HR 1.22; 95% CI 0.83 to 1.80).
In PSP and MSA, survival was predicted by early falls (multivariate HR 2.32; 95% CI 1.94 to 2.77), the Neuroprotection and Natural History in Parkinson Plus Syndromes Parkinson Plus Score and the Clinical Global Impression Disease Severity Score but not sex (multivariate HR 0.93; 95% CI 0.67 to 1.28). There was conflicting evidence regarding the prognostic effect of age at onset and stridor.
Conclusion Several clinical variables were strongly associated with shorter survival in PSP and MSA. Results on most prognostic factors were consistent across methodologically diverse studies; however, the lack of commonality of prognostic factors investigated is a significant limitation
From Escherichia coli heat-stable enterotoxin to mammalian endogenous guanylin hormones
ENHANCED SOLUBILITY AND DISSOLUTION BY SURFACE-MODIFIED SOLID DISPERSION OF ALECTINIB HYDROCHLORIDE
Objective: Alectinib hydrochloride (AH), a poorly soluble drug, exhibits low solubility thereby very low bioavailability. The present study aims to develop and optimize surface-modified solid dispersion of AH (AH-SMSD) with enhanced solubility and dissolution using Soluplus® (SOL) and Gelucire 44/14 (GEL) as a polymer and surfactant respectively.
Methods: Design of Experiments (DoE) was implemented to optimize the weight ratio of SOL (X1), and GEL (X2), keeping the drug weight constant, to maximize the solubility (Y1) and dissolution (Y2). The optimized solid dispersion was subjected to solubility & dissolution in bio-relevant media and characterized using differential scanning calorimetry (DSC), Powder X-ray diffraction (pXRD), Fourier-transform infrared (FTIR), and scanning electron microscopy (SEM).
Results: A statistically significant model is obtained for solubility and dissolution through DoE. Formulation (F9) containing AH:SOL:GEL in weight ratios 1:5:5 showed a 547-fold increase in solubility. This solubility enhancement further translated into dissolution improvement with drug release of >80% in 15 min. The optimized formulation also showed improved solubility and dissolution in fasted-state bio-relevant media. DSC and pXRD showed a change in the crystallinity pattern of the drug. FTIR showed the existence of weak intermolecular interactions. Morphological evaluation through SEM demonstrated that the drug particles were dispersed to a hydrophilic carrier matrix, thus, transforming the hydrophobic drug into a hydrophilic form.
Conclusion: AH-SMSD with enhanced solubility and dissolution was successfully developed. The optimized formulation also showed improvement in the bio-relevant media and therefore has the potential to improve in-vivo oral bioavailability (however, needs to be experimentally explored)
Symptom dimensions in people affected by long-term neurological conditions:a factor analysis of a patient-centred palliative care outcome symptom scale
Abstract Long-term neurological conditions (LTNCs) often cause debilitating symptoms. Better understanding of symptom dimensions in LTNCs is needed to support health professionals and improve care. This can be achieved by exploring the factor structure of a standardised measure of symptoms in LTNC patients. The symptom subscale of the Integrated Palliative Outcome Scale for LTNCs (IPOS Neuro-S24) comprises 24 items measuring symptom severity. Descriptive statistics and psychometric properties of the scale were assessed, followed by differential item functioning (DIF), exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Data from N = 238 patients were analysed. The mean IPOS Neuro S-24 score was 27.0 (possible range 0–96) and floor effects were found for 21 items. The scale had good internal consistency (Cronbach’s alpha = 0.77). Weak evidence of DIF was found for nine items. All but one item (falls) loaded onto four factors with loadings > 0.3. The factors represented four clinically meaningful symptom dimensions: fatigue, motor symptoms, oral problems and non-motor symptoms. We identified a reliable four-factor structure of symptom experience in LTNC patients. The results suggest that symptom dimensions are common across LTNCs. The IPOS Neuro S-24 is an appropriate tool to measure symptoms in LTNC patients, which may improve care
Factors Influencing Driving following DBS Surgery in Parkinson’s Disease: A Single UK Centre Experience and Review of the Literature
Parkinson’s disease (PD) is a complex neurodegenerative disorder, leading to impairment of various neurological faculties, including motor, planning, cognitivity, and executive functions. Motor- and non-motor symptoms of the disease may intensify a patient’s restrictions to performing usual tasks of daily living, including driving. Deep Brain Stimulation (DBS) associated with optimized clinical treatment has been shown to improve quality of life, motor, and non-motor symptoms in PD. In most countries, there are no specific guidelines concerning minimum safety requirements and the timing of return to driving following DBS, leaving to the medical staff of individual DBS centres the responsibility to draw recommendations individually regarding patients’ ability to drive after surgery. The aim of this study was to evaluate factors that might influence the ability to drive following DBS in the management of PD. A total of 125 patients were included. Clinical, epidemiological, neuropsychological, and surgical factors were evaluated. The mean follow-up time was 129.9 months. DBS improved motor and non-motor symptoms of PD. However, in general, patients were 2.8-fold less likely to drive in the postoperative period than prior to surgery. Among the PD characteristics, patients with the akinetic subtype presented a higher risk to lose their driving licence postoperatively. Furthermore, the presence of an abnormal postoperative neuropsychological evaluation was also associated with driving restriction following surgery. Our data indicate that restriction to drive following surgery seems to be multifactorial rather than a direct consequence of DBS itself. Our study sheds light on the urgent need for a standardised multidisciplinary postoperative evaluation to assess patients’ ability to drive following DBS
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Management approach including pembrolizumab for fingolimod-associated progressive multifocal leukoencephalopathy in a patient with relapsing-remitting multiple sclerosis
A 62-year-old man with relapsing-remitting multiple sclerosis developed progressive multifocal leukencephalopathy (PML) after 6 years on fingolimod. The fingolimod was immediately discontinued and preexisting mirtazepine increased. Three weeks later, with brain magnetic resonance imaging (MRI) appearances worsening and cerebrospinal fluid (CSF) JC virus (JCV) titres increasing, maraviroc was introduced. At 6 weeks, subtle punctate contrast enhancement raised the possibility of immune reconstitution inflammatory syndrome (IRIS), followed by a single focal-to-generalised tonic clonic seizure and a further deterioration in clinical disability. Mefloquine was commenced alongside three doses of pembrolizumab administered a month apart. Serial CSF examinations and several imaging modalities including spectroscopy and fused FDG-PET-MRI (18F-fluoro-deoxy-glucose-positron emission tomography-magnetic resonance imaging) were used to help distinguish between PML, PML-IRIS and rebound MS activity and guide optimal management at each stage. A handful of small, enhancing ovoid lesions developed between the first two doses of pembrolizumab, probably representative of a mild rebound phenomenon. A sustained improvement became obvious thereafter with CSF JCV-DNA undetectable 16 weeks following fingolimod withdrawal. To our knowledge, this is the first case of combined therapy and use of pembrolizumab in a fingolimod-associated PML
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The Tangible Benefits of Living Donation: Results of a Qualitative Study of Living Kidney Donors.
UNLABELLED: The framework currently used for living kidney donor selection is based on estimation of acceptable donor risk, under the premise that benefits are only experienced by the recipient. However, some interdependent donors might experience tangible benefits from donation that cannot be considered in the current framework (ie, benefits experienced directly by the donor that improve their daily life, well-being, or livelihood). METHODS: We conducted semistructured interviews with 56 living kidney donors regarding benefits experienced from donation. Using a qualitative descriptive and constant comparative approach, themes were derived inductively from interview transcripts by 2 independent coders; differences in coding were reconciled by consensus. RESULTS: Of 56 participants, 30 were in interdependent relationships with their recipients (shared household and/or significant caregiving responsibilities). Tangible benefits identified by participants fell into 3 major categories: health and wellness benefits, time and financial benefits, and interpersonal benefits. Participants described motivations to donate a kidney based on a more nuanced understanding of the benefits of donation than accounted for by the current acceptable risk paradigm. DISCUSSION: Tangible benefits for interdependent donors may shift the acceptable risk paradigm (where no benefit is assumed) of kidney donor evaluation to a risk/benefit paradigm more consistent with other surgical decision-making