Development of a Nanodroplet Formulation for Triggered Release of BIO for Bone Fracture Healing

Impaired fracture healing impacts patients’ quality of life and imposes a financial burden on healthcare services. Up to 10% of bone fractures result in delayed/non-union fractures, for which new treatments are urgently required. However, systemic delivery of bone anabolic molecules is often sub-optimal and can lead to significant side effects. In this study, we developed ultrasound (US) responsive nano-sized vehicles in the form of perfluorocarbon nanodroplets (NDs), as a means of targeting delivery of drugs to localised tissues. We tested the hypothesis that NDs could stably encapsulate BIO (GSK-3β inhibitor), which could then be released upon US stimulation to activate Wnt signalling and induce ossification. NDs (~280 nm) were prepared from phospholipids and liquid perfluorocarbon and their stability and drug loading was studied by NTA (Nano Tracking Analysis) and HPLC. ND cytotoxicity was assessed in patient-derived bone marrow stromal cells (BMSCs) with Alamar Blue (24 h), and in vitro bioactivity of BIO-NDs was evaluated in a 3T3 Wnt-pathway reporter cell line with luciferase readout. To investigate the acoustic behaviour of NDs, 2% agarose (LM) containing NDs was injected into a bespoke bone fracture model (Sawbones) of various geometries and stimulated by US (1 MHz, 5% duty cycle, 1 MPa, 30 s), allowing the simultaneous capture of optical images and acoustic emissions. Femoral bone hole defects (1–2 mm) were made in WT-MF1 mice (age: 8–12 wks) and DiR-labelled NDs (100 µL, 109 NDs/mL, i.v.) were injected post-fracture to determine biodistribution by IVIS imaging. NDs were stable (4 and 37 °C) and retained >90% BIO until US was applied, which caused ~100% release. ND exposure up to a concentration of 109 NDs/mL showed no cytotoxicity (24 h). BIO-loaded NDs induced Wnt pathway activation in a dose dependent manner. Biodistribution of DiR-NDs in a femoral bone hole defect model in mice demonstrated increased localisation at the fracture site (~2-fold relative to that found in healthy mice or contralateral femurs at 48 h)

Rethinking the patient: using Burden of Treatment Theory to understand the changing dynamics of illness

<b>Background</b> In this article we outline Burden of Treatment Theory, a new model of the relationship between sick people, their social networks, and healthcare services. Health services face the challenge of growing populations with long-term and life-limiting conditions, they have responded to this by delegating to sick people and their networks routine work aimed at managing symptoms, and at retarding - and sometimes preventing - disease progression. This is the new proactive work of patient-hood for which patients are increasingly accountable: founded on ideas about self-care, self-empowerment, and self-actualization, and on new technologies and treatment modalities which can be shifted from the clinic into the community. These place new demands on sick people, which they may experience as burdens of treatment.<p></p> <b>Discussion</b> As the burdens accumulate some patients are overwhelmed, and the consequences are likely to be poor healthcare outcomes for individual patients, increasing strain on caregivers, and rising demand and costs of healthcare services. In the face of these challenges we need to better understand the resources that patients draw upon as they respond to the demands of both burdens of illness and burdens of treatment, and the ways that resources interact with healthcare utilization.<p></p> <b>Summary</b> Burden of Treatment Theory is oriented to understanding how capacity for action interacts with the work that stems from healthcare. Burden of Treatment Theory is a structural model that focuses on the work that patients and their networks do. It thus helps us understand variations in healthcare utilization and adherence in different healthcare settings and clinical contexts

Tailoring the size of ultrasound responsive lipid-shelled nanodroplets by varying production parameters and environmental conditions

Liquid perfluorocarbon nanodroplets (NDs) are an attractive alternative to microbubbles (MBs) for ultrasound-mediated therapeutic and diagnostic applications. ND size and size distribution have a strong influence on their behaviour in vivo, including extravasation efficiency, circulation time, and response upon ultrasound stimulation. Thus, it is desirable to identify ways to tailor the ND size and size distribution during manufacturing. In this study phospholipid-coated NDs, comprising a perfluoro-n-pentane (PFP) core stabilised by a DSPC/PEG40s (1,2-distearoyl-sn-glycero-3-phosphocholine and polyoxyethylene(40)stearate, 9:1 molar ratio) shell, were produced in phosphate-buffered saline (PBS) by sonication. The effect of the following production-related parameters on ND size was investigated: PFP concentration, power and duration of sonication, and incorporation of a lipophilic fluorescent dye. ND stability was also assessed at both 4°C and 37°C. When a sonication pulse of 6 s and 15% duty cycle was employed, increasing the volumetric concentration of PFP from 5% to 15% v/v in PBS resulted in an increase in ND diameter from 215.8 ± 16.8 nm to 408.9 ± 171.2 nm. An increase in the intensity of sonication from 48 to 72 W (with 10% PFP v/v in PBS) led to a decrease in ND size from 354.6 ± 127.2 nm to 315.0 ± 100.5 nm. Increasing the sonication time from 20 s to 40 s (using a pulsed sonication with 30% duty cycle) did not result in a significant change in ND size (in the range 278 - 314 nm); however, when it was increased to 60 s, the average ND diameter reduced to 249.7 ± 9.7 nm, which also presented a significantly lower standard deviation compared to the other experimental conditions investigated (i.e., 9.7 nm vs. > 49.4 nm). The addition of the fluorescent dye DiI at different molar ratios did not affect the ND size distribution. NDs were stable at 4°C for up to 6 days and at 37°C for up to 110 min; however, some evidence of ND-to-MB phase transition was observed after 40 min at 37°C. Finally, phase transition of NDs into MBs was demonstrated using a tissue-mimicking flow phantom under therapeutic ultrasound exposure conditions (ultrasound frequency: 0.5 MHz, acoustic pressure: 2-4 MPa, and pulse repetition frequency: 100 Hz)

Retrospective survey for sialidase activity in Mycoplasma pneumoniae isolates from cases of community-acquired pneumonia

<p>Abstract</p> <p>Background</p> <p>Sialidase is a well-known virulence factor of other respiratory pathogens, but was only recently documented to occur in some species of <it>Mycoplasma</it>. The sialidase activity expressed can vary quantitatively among strains within a species of mycoplasma, from undetectable to amounts that correlate positively with strain virulence. Very few isolates of <it>Mycoplasma pneumoniae </it>had ever been examined for sialidase activity, so it was unknown whether sialidase may contribute to diseases involving this species.</p> <p>Findings</p> <p>No sialidase activity was detected by spectrofluorometric assay of 15 laboratory strains and 91 clinical isolates of <it>M. pneumoniae </it>banked over many years from patients having radiologically-confirmed, uncomplicated community-acquired pneumonia.</p> <p>Conclusions</p> <p>The annotated genome of strain M129 (GenBank <ext-link ext-link-id="NC_000912" ext-link-type="gen">NC_000912</ext-link>, <ext-link ext-link-id="ATCC29342" ext-link-type="gen">ATCC 29342</ext-link>), also isolated from a patient with pneumonia, accurately represents the absence of sialidase genes from strains of <it>M. pneumoniae </it>typically associated with uncomplicated community-acquired pneumonia. A possible involvement of sialidase in neurologic or other extra-respiratory manifestations of <it>M. pneumoniae </it>mycoplasmosis remains to be investigated.</p

Uncovering treatment burden as a key concept for stroke care: a systematic review of qualitative research

&lt;b&gt;Background&lt;/b&gt; Patients with chronic disease may experience complicated management plans requiring significant personal investment. This has been termed ‘treatment burden’ and has been associated with unfavourable outcomes. The aim of this systematic review is to examine the qualitative literature on treatment burden in stroke from the patient perspective.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods and findings&lt;/b&gt; The search strategy centred on: stroke, treatment burden, patient experience, and qualitative methods. We searched: Scopus, CINAHL, Embase, Medline, and PsycINFO. We tracked references, footnotes, and citations. Restrictions included: English language, date of publication January 2000 until February 2013. Two reviewers independently carried out the following: paper screening, data extraction, and data analysis. Data were analysed using framework synthesis, as informed by Normalization Process Theory. Sixty-nine papers were included. Treatment burden includes: (1) making sense of stroke management and planning care, (2) interacting with others, (3) enacting management strategies, and (4) reflecting on management. Health care is fragmented, with poor communication between patient and health care providers. Patients report inadequate information provision. Inpatient care is unsatisfactory, with a perceived lack of empathy from professionals and a shortage of stimulating activities on the ward. Discharge services are poorly coordinated, and accessing health and social care in the community is difficult. The study has potential limitations because it was restricted to studies published in English only and data from low-income countries were scarce.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt; Stroke management is extremely demanding for patients, and treatment burden is influenced by micro and macro organisation of health services. Knowledge deficits mean patients are ill equipped to organise their care and develop coping strategies, making adherence less likely. There is a need to transform the approach to care provision so that services are configured to prioritise patient needs rather than those of health care systems

What traits are carried on mobile genetic elements, and why?

Although similar to any other organism, prokaryotes can transfer genes vertically from mother cell to daughter cell, they can also exchange certain genes horizontally. Genes can move within and between genomes at fast rates because of mobile genetic elements (MGEs). Although mobile elements are fundamentally self-interested entities, and thus replicate for their own gain, they frequently carry genes beneficial for their hosts and/or the neighbours of their hosts. Many genes that are carried by mobile elements code for traits that are expressed outside of the cell. Such traits are involved in bacterial sociality, such as the production of public goods, which benefit a cell's neighbours, or the production of bacteriocins, which harm a cell's neighbours. In this study we review the patterns that are emerging in the types of genes carried by mobile elements, and discuss the evolutionary and ecological conditions under which mobile elements evolve to carry their peculiar mix of parasitic, beneficial and cooperative genes

Age, Disease Severity and Ethnicity Influence Humoral Responses in a Multi-Ethnic COVID-19 Cohort

The COVID-19 pandemic has affected all individuals across the globe in some way. Despite large numbers of reported seroprevalence studies, there remains a limited understanding of how the magnitude and epitope utilization of the humoral immune response to SARS-CoV-2 viral anti-gens varies within populations following natural infection. Here, we designed a quantitative, multi-epitope protein microarray comprising various nucleocapsid protein structural motifs, including two structural domains and three intrinsically disordered regions. Quantitative data from the microarray provided complete differentiation between cases and pre-pandemic controls (100% sensitivity and specificity) in a case-control cohort (n = 100). We then assessed the influence of disease severity, age, and ethnicity on the strength and breadth of the humoral response in a multi-ethnic cohort (n = 138). As expected, patients with severe disease showed significantly higher antibody titers and interestingly also had significantly broader epitope coverage. A significant increase in antibody titer and epitope coverage was observed with increasing age, in both mild and severe disease, which is promising for vaccine efficacy in older individuals. Additionally, we observed significant differences in the breadth and strength of the humoral immune response in relation to ethnicity, which may reflect differences in genetic and lifestyle factors. Furthermore, our data enabled localization of the immuno-dominant epitope to the C-terminal structural domain of the viral nucleocapsid protein in two independent cohorts. Overall, we have designed, validated, and tested an advanced serological assay that enables accurate quantitation of the humoral response post natural infection and that has revealed unexpected differences in the magnitude and epitope utilization within a population

(Re)Storying Obama: An Examination of Recently Published Informational Texts

American publishers have published numerous children’s books about Barack Obama over the past several years; most take the form of informational biographies. This article reports on a research project aimed at how these books incorporate sociohistorical narratives, particularly those related to the civil rights movement. Though the features of the books might cause the reader to presume political neutrality, the books link readers to distinct Discourses (Gee, 1996), suggesting particular ideologies. In this article, we identified the following differences: (1) specific happenings from Obama’s life were included in some texts while omitted in others; (2) when the events were included, how they were framed differed; and (3) the narrative constructions of the events varied. We use the differences amongst these texts to argue for the importance of critical literacy in elementary classrooms

Compartments revealed in food-web structure

Compartments(1) in food webs are subgroups of taxa in which many strong interactions occur within the subgroups and few weak interactions occur between the subgroups(2). Theoretically, compartments increase the stability in networks(1-5), such as food webs. Compartments have been difficult to detect in empirical food webs because of incompatible approaches(6-9) or insufficient methodological rigour(8,10,11). Here we show that a method for detecting compartments from the social networking science(12-14) identified significant compartments in three of five complex, empirical food webs. Detection of compartments was influenced by food web resolution, such as interactions with weights. Because the method identifies compartmental boundaries in which interactions are concentrated, it is compatible with the definition of compartments. The method is rigorous because it maximizes an explicit function, identifies the number of non-overlapping compartments, assigns membership to compartments, and tests the statistical significance of the results(12-14). A graphical presentation(14) reveals systemic relationships and taxa-specific positions as structured by compartments. From this graphic, we explore two scenarios of disturbance to develop a hypothesis for testing how compartmentalized interactions increase stability in food webs(15-17).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62960/1/nature02115.pd

Altered expression of a putative progenitor cell marker DCAMKL1 in the rat gastric mucosa in regeneration, metaplasia and dysplasia

<p>Abstract</p> <p>Background</p> <p>Doublecortin and calcium/calmodulin-dependent protein kinase-like-1 (DCAMKL1) is a candidate marker for progenitor cells in the gastrointestinal mucosa. Lineage cells in the gastric mucosa are derived from progenitor cells, but this process can be altered after injury. Therefore, we explored DCAMKL1 expression under pathological conditions.</p> <p>Methods</p> <p>An immunohistochemical analysis was performed in rat stomach with acute superficial injury, chronic ulcer, intestinal metaplasia and dysplasia.</p> <p>Results</p> <p>DCAMKL1 was exclusively expressed in immature quiescent cells in the isthmus of normal fundic glands, where putative progenitor cells are thought to reside. DCAMKL1-positive cells and proliferating cells shed into the lumen after superficial injury and re-appeared during the regenerative process, mainly in the superficial mucosa. In the marginal mucosa around the active ulcer, parietal and chief cells diminished, foveolar hyperplasia was evident, and trefoil factor family 2 (TFF2)/spasmolytic polypeptide-expressing metaplasia (SPEM) emerged at the gland base. DCAMKL1 cells re-emerged in the deep mucosa juxtaposed with SPEM and proliferating cells. In the healing ulcer, the TFF2 cell population expanded and seemed to redifferentiate to chief cells, while proliferating cells and DCAMKL1 cells appeared above and below the TFF2 cells to promote healing. SPEM appeared and PCNA cells increased in the intestinalized mucosa, and DCAMKL1 was expressed in the proximity of the PCNA cells in the deep mucosa. DCAMKL1, PCNA and TFF2 were expressed in different dysplastic cells lining dilated glands near SPEM.</p> <p>Conclusion</p> <p>The ultrastructural appearance of DCAMKL1-positive cells and the expression patterns of DCAMKL1 in normal and pathological states indicate that the cells belong to a progenitor cell population. DCAMKL1 expression is closely associated with TFF2/SPEM cells after injury. DCAMKL1 cells repopulate close to proliferating, hyperplastic, metaplastic and dysplastic cells, and the progenitor zone shifts according to the pathological circumstances.</p