Search

Over the last decade, video-enabled mobile devices have become almost ubiquitous, while advances in markerless pose estimation allow an individual's body position to be tracked across the frames of a video. Previous work by this and other groups has shown that pose-extracted kinematic features can be used to reliably measure motor impairment in Parkinson's disease (PD). This presents the prospect of developing an asynchronous and scalable, video-based assessment of motor dysfunction. Crucial to this endeavour is the ability to automatically recognise the class of an action being performed, without which manual labelling is required. Representing the evolution of body joint locations as a spatio-temporal graph, we implement a deep-learning model for frame-level classification of activities performed according to part 3 of the Movement Disorder Society Unified PD Rating Scale (MDS-UPDRS). We train and validate this system using a dataset of n=7220 video clips, recorded at 5 independent sites. This approach achieves human-level performance in classifying and labelling periods of activity within monocular video clips. Our framework could support clinical workflows and patient care at scale through applications such as quality monitoring of clinical data collection, automated labelling of video streams, or a module within a remote self-assessment system.

Recent advances in molecular biology have led to the CRISPR revolution, but the lack of an efficient and safe delivery system into cells and tissues continues to hinder clinical translation of CRISPR approaches. Polymeric vectors offer an attractive alternative to viruses as delivery vectors due to their large packaging capacity and safety profile. In this paper, we have demonstrated the potential use of a highly branched poly(β-amino ester) polymer, HPAE-EB, to enable genomic editing via CRISPRCas9-targeted genomic excision of exon 80 in the COL7A1 gene, through a dual-guide RNA sequence system. The biophysical properties of HPAE-EB were screened in a human embryonic 293 cell line (HEK293), to elucidate optimal conditions for efficient and cytocompatible delivery of a DNA construct encoding Cas9 along with two RNA guides, obtaining 15–20% target genomic excision. When translated to human recessive dystrophic epidermolysis bullosa (RDEB) keratinocytes, transfection efficiency and targeted genomic excision dropped. However, upon delivery of CRISPR–Cas9 as a ribonucleoprotein complex, targeted genomic deletion of exon 80 was increased to over 40%. Our study provides renewed perspective for the further development of polymer delivery systems for application in the gene editing field in general, and specifically for the treatment of RDEB.

Human vision is attuned to the subtle differences between individual faces. Yet we lack a quantitative way of predicting how similar two face images look and whether they appear to show the same person. Principal component–based three-dimensional (3D) morphable models are widely used to generate stimuli in face perception research. These models capture the distribution of real human faces in terms of dimensions of physical shape and texture. How well does a “face space” based on these dimensions capture the similarity relationships humans perceive among faces? To answer this, we designed a behavioral task to collect dissimilarity and same/different identity judgments for 232 pairs of realistic faces. Stimuli sampled geometric relationships in a face space derived from principal components of 3D shape and texture (Basel face model [BFM]). We then compared a wide range of models in their ability to predict the data, including the BFM from which faces were generated, an active appearance model derived from face photographs, and image-computable models of visual perception. Euclidean distance in the BFM explained both dissimilarity and identity judgments surprisingly well. In a comparison against 16 diverse models, BFM distance was competitive with representational distances in state-of-the-art deep neural networks (DNNs), including novel DNNs trained on BFM synthetic identities or BFM latents. Models capturing the distribution of face shape and texture across individuals are not only useful tools for stimulus generation. They also capture important information about how faces are perceived, suggesting that human face representations are tuned to the statistical distribution of faces.

Composed of a three-dimensional structure with a central core and multiple radiating linear “arms”, star polymers represent a significant type of branched macromolecular architectures. Due to the spatially defined core–shell-periphery architecture, star polymers have demonstrated their superiority in a variety of biomedical applications such as drug/gene delivery, molecular imaging, antibacterial agents, and so on. In this paper, we report the successful synthesis of a new type of star-shape poly(β-amino esters) with low molecular weight PEI as core and linear PAE (LPAE) as arms. This new star-PAE exhibits low cytotoxicity and high gene transfection efficacy. Star-PAE achieved between 264-fold and 14781-fold higher gene transfection efficiency of primary rat adipose derived mesenchymal stem cells in comparison with studies performed with the individual PEI and LPAE, respectively. The results suggest that star-PAE is a promising nonviral gene delivery vector.

Gait is a core motor function and is impaired in numerous neurological diseases, including Parkinson’s disease (PD). Treatment changes in PD are frequently driven by gait assessments in the clinic, commonly rated as part of the Movement Disorder Society (MDS) Unified PD Rating Scale (UPDRS) assessment (item 3.10). We proposed and evaluated a novel approach for estimating severity of gait impairment in Parkinson’s disease using a computer vision-based methodology. The system we developed can be used to obtain an estimate for a rating to catch potential errors, or to gain an initial rating in the absence of a trained clinician—for example, during remote home assessments. Videos (n=729) were collected as part of routine MDS-UPDRS gait assessments of Parkinson’s patients, and a deep learning library was used to extract body key-point coordinates for each frame. Data were recorded at five clinical sites using commercially available mobile phones or tablets, and had an associated severity rating from a trained clinician. Six features were calculated from time-series signals of the extracted key-points. These features characterized key aspects of the movement including speed (step frequency, estimated using a novel Gamma-Poisson Bayesian model), arm swing, postural control and smoothness (or roughness) of movement. An ordinal random forest classification model (with one class for each of the possible ratings) was trained and evaluated using 10-fold cross validation. Step frequency point estimates from the Bayesian model were highly correlated with manually labelled step frequencies of 606 video clips showing patients walking towards or away from the camera (Pearson’s r=0.80, p&lt, 0.001). Our classifier achieved a balanced accuracy of 50% (chance = 25%). Estimated UPDRS ratings were within one of the clinicians’ ratings in 95% of cases. There was a significant correlation between clinician labels and model estimates (Spearman’s ρ=0.52, p&lt, 0.001). We show how the interpretability of the feature values could be used by clinicians to support their decision-making and provide insight into the model’s objective UPDRS rating estimation. The severity of gait impairment in Parkinson’s disease can be estimated using a single patient video, recorded using a consumer mobile device and within standard clinical settings, i.e., videos were recorded in various hospital hallways and offices rather than gait laboratories. This approach can support clinicians during routine assessments by providing an objective rating (or second opinion), and has the potential to be used for remote home assessments, which would allow for more frequent monitoring.

Background Older people living in nursing homes (NHs) are among the most frail and vulnerable in our community. Over the last 5 years, a review of our local NH admission database revealed a 7% increase in the number of unscheduled hospital attendances from NHs (1015 in 2012/13 vs 1435 in 2016/17). Additionally we have seen an increase in the number of NH residents experiencing ≥2 unscheduled re-admissions within one year (21.1% in 2012/13 vs 30.45% in 2016/17). Our aim was to examine the proportion of patients from NHs who died within 24 hours of presentation, prompting a review of methods that could prevent inappropriate hospital transfers and promoting dignified and comfortable end of life care. Methods A prospective database was collected between 01/01/2016 - 31/12/2017. This recorded all emergency admissions of older people from NHs recording length of stay, readmission rates and mortality. The data was retrospectively analysed, looking specifically at patients who died in hospital ≤ 24 hours Results Of 1435 ED admissions, 49 patients (3.4%) died in hospital ≤ 24 hours after presentation. Of these, 31 patients (61%) died in palliative care suites. 8 patients (16.3%) died in the ED. Conclusion A small number of NH residents presenting to our hospital died within 24 hours. A large proportion of these patients died in a palliative care suite, suggesting poor prognosis was identified rapidly after presentation. We wonder if some of these hospital transfers were avoidable and could certain patients have experienced less disruptive deaths in their NHs? Advanced Care Planning can be difficult for all involved. However, it plays an essential role in ensuring people receive the right care, at the right time, in the right place, from the right team. We support the collaborative roles of a palliative care CNS or Geriatric ANP, and integration with NH Outreach services, to facilitate early decision-making and promote better end of life care.

Background There is an increasing number of older persons experiencing transfer episodes between residential and acute care facilities (Griffiths et al. 2014). Current transfer documentation is diverse; often only containing basic information and very little person centred patient information. The objective of this HSE National Clinical Programme for Older People funded study was to develop a national person centred transfer tool, for use during patient transfer between residential and acute services. Following an extensive literature review, focus group interviews with stakeholders and input from an expert panel, a pilot transfer document was developed. This paper reports on the pilot study of this document. Methods Researchers, in consultation with the expert panel, developed questionnaires. Questionnaires were quantitative, with three open-ended questions. Of the 28 residential settings and 3 acute settings that were contacted, 26 residential and 3 acute settings (93%) participated in the study. The pre-pilot questionnaire asked staff in residential settings their perceptions on current transfer documentation (n=875). The post-pilot questionnaire asked staff in residential and acute care settings their thoughts on the new transfer document which was used for the pilot (n=1085). Results Findings suggest that staff agree that the new transfer tool is person centred, contains relevant patient information and could help communication between healthcare professionals in these settings. Findings also indicate that the length of time to complete the document is of concern, particularly in an emergency and there were suggestions from staff in residential care services that some sections could be prepopulated. Conclusion In order to have a transfer document that is efficient, and person centred, there is a need for it to be available electronically and easy for staff to fully complete particularly in an emergency transfer.

Background Older people living in Nursing Homes (NHs) represent a frail and vulnerable group. With multiple co-morbidities they are at increased risk of acute health deterioration prompting urgent hospital transfer. Our aim was to examine the outcomes for nursing home residents following unscheduled hospital attendances. Methods A prospective database was collected between 1 January 2016 and 31 December 2017. This recorded all emergency admissions of older people from NHs. The data was retrospectively analysed. Outcomes assessed included: length of stay (LOS), 30-day readmission rates, number of readmissions within one year and mortality. We compared these results to similar data collected in 2012-13. Results Over a two-year period, there were 1435 hospital admissions; a 7% increase from 1015 in 2012. 60% were female and 40% male with a mean age of 84.7 years. The average LOS was 9.58 days (vs 11.2 days in 2012-13). The 30-day readmission rate was 9.8% (vs 14% in 2012-13). 30.45% of all patients went on to have 2 or more readmissions within one year, an increase from 21.1% in 2012-13. The total in-hospital mortality was 14%. Conclusion An increase in the number of NH residents presenting to an acute hospital over the past 5 years was observed. Despite this, we have seen reductions in average LOS and 30 day readmission rates. There is, however, an increasing number of recurrent admissions (≥ 2) to the hospital within one year. These results highlight the importance of an integrated approach to patient care; from the primary care team, hospital team, palliative and community care services. We believe the continued development of Nursing Home Outreach Programmes and community liaison services, combined with the evolving role of the in-hospital Geriatric ANP and liaison palliative care team, will help reduce inappropriate ED referrals and encourage advanced care planning.

Using a combined synthesis approach comprising reversible addition-fragmentation transfer polymerization and ring opening reaction, a series of poly glycidyl methacrylate (polyGMA) polymers were designed and synthesized for gene delivery. These polymers characterized by low cationic charge respective to established gene delivery vectors such as PEI were studied to further elucidate the key structure-activity parameters that mediate efficient and biocompatible gene delivery. Compared to PEI, these brushlike polymers facilitated markedly improved safety and gene delivery efficiency.

We report a new type of thermo- and pH-responsive, coacervate-forming highly degradable polymer-hyperbranched poly(β-amino esters) (HPAEs) and its selective cell binding behaviors. The HPAEs were synthesized from 5-amino-1-pentanol (S5) and trimethylolpropane ethoxylate triacrylate (TMPETA) via an A2+B3 type Michael addition. The existence of multiple hydrogen bond pairs as well as tertiary amines makes the S5-TMPETA polymers manifest temperature- and pH-dependent phase transition. By varying the length of the ethylene glycol (EG) spacers in the TMPETA, polymer molecular weight, concentration, and pH value, the phase transition of the S5-TMPETA can be easily tuned in aqueous and buffer solutions, as evidenced by UV-vis spectroscopy and DLS measurements. Especially, the S5-TMPETA prepared from S5 and trimethylolpropane ethoxylate triacrylate 692 (S5-TMPETA692) shows a lower critical solution temperature (LCST) around 33 °C, above which the S5-TMPTEA can form coacervate particles able to encapsulate functional molecules effectively. Importantly, when incubation with HeLa cells, the S5-TMPTETA692 exhibits a temperature- and pH-responsive selective cell binding behaviors. In addition, the S5-TMPETA are highly hydrolyzable and elicit negligible cytotoxicity. This new type of "smart" polymer should find use in a variety of biomedical applications.

Gene therapy has long been held as having the potential to become a front line treatment for various genetic disorders. However, the direct delivery of nucleic acids to correct a genetic disorder has numerous limitations owing to the inability of naked nucleic acids (DNA and RNA) to traverse the cell membrane. Recently, messenger RNA (mRNA) based delivery has become a more attractive alternative to DNA due to the relatively easier transfection process, higher efficiency and safety profile. As with all gene therapies, the central challenge that remains is the efficient delivery of nucleic acids intracellularly. This review presents the recent progress in mRNA delivery, focusing on comparing the advantages and limitations of non-viral based delivery vectors.

Current therapies for most neurodegenerative disorders are only symptomatic in nature and do not change the course of the disease. Gene therapy plays an important role in disease modifying therapeutic strategies. Herein, we have designed and optimized a series of highly branched poly(β-amino ester)s (HPAEs) containing biodegradable disulfide units in the HPAE backbone (HPAESS) and guanidine moieties (HPAESG) at the extremities. The optimized polymers are used to deliver minicircle DNA to multipotent adipose derived stem cells (ADSCs) and astrocytes, and high transfection efficiency is achieved (77% in human ADSCs and 52% in primary astrocytes) whilst preserving over 90% cell viability. Furthermore, the top-performing candidate mediates high levels of nerve growth factor (NGF) secretion from astrocytes, causing neurite outgrowth from a model neuron cell line. This synergistic gene delivery system provides a viable method for highly efficient non-viral transfection of ADSCs and astrocytes., Therapeutics delivery by using non-viral vectors presents several challenges in the design of an appropriate polymeric structure. Here, the authors report a series of highly branched, biodegradable polymers which show high transfection efficiency in human multipotent adipose derived stem cells and primary astrocytes.

Polymerization of multifunctional monomers could produce polymers with different functionalities and novel macromolecular architectures. However, the ability to control the homopolymerization of multivinyl monomers (MVMs) has always been a challenge. Here we demonstrate that the homopolymerization of acrylate based MVMs can be kinetically controlled via Cu0-mediated controlled/living radical polymerization in the presence of additional CuII, which enables the efficient promotion of intramolecular cyclization and suppression of intermolecular cross-linking. The gelation is effectively delayed over ca. 40% monomer conversion in the concentrated polymerization system ([M] = 40.9 wt %), which is far higher than the Flory–Stockmayer theory predicts. Moreover, closer inspection of the synthesized polymers reveals that single-chain cyclized/knotted polymeric nanoparticles (SCKNPs) are formed due to the nature of one-pot in situ intramolecular reaction and self-cyclization of the propagating polymer chains. This ...

Highly branched poly(β-amino ester)s (HPAEs) were designed and synthesised for safe and efficient gene delivery to human keratinocytes. HPAEs outperformed commercial transfection reagents: PEI and SuperFect®, for both transfection efficiency and biocompatibility. A 22 and 3.4 fold enhancement of gene transfection was seen coupled with superior biocompatibility.

The top-performing linear poly(β-amino ester) (LPAE), poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) (C32), has demonstrated gene transfection efficiency comparable to viral-mediated gene delivery. Herein, we report the synthesis of a series of highly branched poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) (HC32) and explore how the branching structure influences the performance of C32 in gene transfection. HC32 were synthesized by an “A2 + B3 + C2” Michal addition strategy. Gaussia luciferase (Gluciferase) and green fluorescent protein (GFP) coding plasmid DNA were used as reporter genes and the gene transfection efficiency was evaluated in human cervical cancer cell line (HeLa) and human recessive dystrophic epidermolysis bullosa keratinocyte (RDEBK) cells. We found that the optimal branching structure led to a much higher gene transfection efficiency in comparison to its linear counterpart and commercial reagents, while preserving high cell viability in both cell types. The branching strategy affected DNA binding, proton buffering capacity and degradation of polymers as well as size, zeta potential, stability, and DNA release rate of polyplexes significantly. Polymer degradation and DNA release rate played pivotal parts in achieving the high gene transfection efficiency of HC32-103 polymers, providing new insights for the development of poly(β-amino ester)s-based gene delivery vectors.

One of the most significant challenges in the development of polymer materials for gene delivery is to understand how topological structure influences their transfection properties. Poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) (C32) has proven to be the top-performing gene delivery vector developed to date. Here, we report the development of branched poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) (HC32) as a novel gene vector and elucidate how the topological structure affects gene delivery properties. We found that the branched structure has a big impact on gene transfection efficiency resulting in a superior transfection efficiency of HC32 in comparison to C32 with a linear structure. Mechanistic investigations illustrated that the branched structure enhanced DNA binding, leading to the formation of toroidal polyplexes with smaller size and higher cationic charge. Importantly, the branched structure offers HC32 a larger chemical space for terminal functionalization (e.g., guanidinylation) to further enhance the transfection. Moreover, the optimized HC32 is capable of transfecting a diverse range of cell types including cells that are known to be difficult to transfect such as stem cells and astrocytes with high efficiency. Our study provides a new insight into the rational design of poly(β-amino ester) (PAE) based polymers for gene delivery.

A successful polymeric gene delivery vector is denoted by both transfection efficiency and biocompatibility. However, the existing vectors with combined high efficacy and minimal toxicity still fall short. The most widely used polyethylene imine (PEI), polyamidoamine (PAMAM) and poly(dimethylaminoethyl methacrylate) (PDMAEMA) suffer from the correlation: either too toxic or little effective. Here, we demonstrate that with highly branched poly(β-amino esters) (HPAEs), a type of recently developed gene delivery vector, the high gene transfection efficiency and low cytotoxicity can be achieved simultaneously at high molecular weight (MW). The interactions of HPAE/DNA polyplexes with cell membrane account for the favorable correlation between molecular weight and biocompatibility. In addition to the effect of molecular weight, the molecular configuration of linear and branched segments in HPAEs is also pivotal to endow high transfection efficiency and low cytotoxicity. These findings provide renewed perspective for the further development of clinically viable gene delivery vectors.

Natural polycations, such as poly(L-lysine) (PLL) and chitosan (CS), have inherent superiority as non-viral vectors due to their unparalleled biocompatibility and biodegradability. However, the application was constrained by poor transfection efficiency and safety concerns. Since previous modification strategies greatly weakened the inherent advantages of natural polycations, developing a strategy for functional group introduction with broad applicability to enhance the transfection efficiency of natural polycations without compromising their cationic properties is imperative. Herein, two uncharged functional diblock oligomers P(DMAEL-b-NIPAM) and P(DMAEL-b-Vlm) were prepared from a lactose derivative, N-iso-propyl acrylamide (NIPAM) as well as 1-vinylimidazole (Vlm) and further functionalized with four small ligands folate, glutathione, cysteine and arginine, respectively, aiming to enhance the interactions of complexes with cells, which were quantified utilizing a quartz crystal microbalance (QCM) biosensor, circumventing the tedious material screening process of cell transfection. Upon incorporation with PLL and DNA, the multifunctional oligomers endow the formulated ternary complexes with great properties suitable for transfection, such as anti-aggregation in serum, destabilized endosome membrane, numerous functional sites for promoted endocytosis and therefore robust transfection activity. Furthermore, different from the conventional strategy of decreasing cytotoxicity by reducing the charge density, the multifunctional oligomer incorporation strategy maintains the highly positive charge density, which is essential for efficient cellular uptake. This system develops a new platform to modify natural polycations towards clinical gene therapy.

Highly branched poly(β-amino ester) polymers are developed to carry a gene and to enter cells for the production of protein., Nonviral gene therapy holds great promise but has not delivered treatments for clinical application to date. Lack of safe and efficient gene delivery vectors is the major hurdle. Among nonviral gene delivery vectors, poly(β-amino ester)s are one of the most versatile candidates because of their wide monomer availability, high polymer flexibility, and superior gene transfection performance both in vitro and in vivo. However, to date, all research has been focused on vectors with a linear structure. A well-accepted view is that dendritic or branched polymers have greater potential as gene delivery vectors because of their three-dimensional structure and multiple terminal groups. Nevertheless, to date, the synthesis of dendritic or branched polymers has been proven to be a well-known challenge. We report the design and synthesis of highly branched poly(β-amino ester)s (HPAEs) via a one-pot “A2 + B3 + C2”–type Michael addition approach and evaluate their potential as gene delivery vectors. We find that the branched structure can significantly enhance the transfection efficiency of poly(β-amino ester)s: Up to an 8521-fold enhancement in transfection efficiency was observed across 12 cell types ranging from cell lines, primary cells, to stem cells, over their corresponding linear poly(β-amino ester)s (LPAEs) and the commercial transfection reagents polyethyleneimine, SuperFect, and Lipofectamine 2000. Moreover, we further demonstrate that HPAEs can correct genetic defects in vivo using a recessive dystrophic epidermolysis bullosa graft mouse model. Our findings prove that the A2 + B3 + C2 approach is highly generalizable and flexible for the design and synthesis of HPAEs, which cannot be achieved by the conventional polymerization approach; HPAEs are more efficient vectors in gene transfection than the corresponding LPAEs. This provides valuable insight into the development and applications of nonviral gene delivery and demonstrates great prospect for their translation to a clinical environment.

Psychiatry differs from other clinical specialties in several important respects. At a basic level, physical examination of the body is conspicuously absent in psychiatry. The diagnostic process employs almost no physical laboratory-based tests such as blood, urine, or CSF (cerebrospinal fluid) analysis. Nor are the various imaging modalities instrumental in diagnosing a psychiatric condition. Such investigations are almost ubiquitous elsewhere in medicine, yet insofar as they are utilized in psychiatry they are overwhelmingly aimed at excluding non-psychiatric conditions. Moreover, modern-day psychiatry is, more than any medical specialty, a minefield of controversy. Psychoanalysis, for example, still widely practised, is viewed by many psychiatrists in the field as little more than quackery (Webster 1996), and even within the disciplined ranks of those committed to neurobiological models of disease disagreement exists as to whether schizophrenia and bipolar disorder represent distinct pathologies (Maier, Zobel and Wagner 2006). As if the unusual nature and degree of internal debate regarding psychiatric theories and therapies were not enough, controversy extends so far as to question the very existence of psychiatric conditions. As Thomas Szasz, Professor of Psychiatry at Syracuse University, famously opined, '“mental illness” is not the name of a biological condition' (Szasz 1973).