155 research outputs found
Recurrent symptomatic aortic sac seroma after open abdominal aortic aneurysm repair
The expansion of an abdominal aortic aneurysm sac after conventional repair has been rarely described. All cases in the literature have been associated with polytetrafluoroethylene grafts and perigraft seromas. We present a patient with a recurrent, symptomatic periaortic graft seroma after conventional repair. The etiology of this problem along with its potential increasing significance in the endovascular era is reviewed
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Microencapsulation process
Nylon coated microcapsules containing hydrophilic solvent-soluble anionic, cationic or quaternary drug salts were prepared by interfacial polycondensation techniques. In a first stage, the drug substance to be encapsulated is dissolved in an aqueous phase. Examples of drugs encapsulated are morphine sulfate, diphenhydramine hydrochloride, and methantheline bromide. Next the aqueous drug solution is dispersed in an organic phase. In a second stage complementary polycondensation reactants each in an organic phase are added separately, either sequentially or simultaneously, to the dispersion prepared in the first stage. Microcapsules of nylon form around the hydrophilic solvent soluble core drug substance.Board of Regents, University of Texas Syste
The medical science DMZ: a network design pattern for data-intensive medical science
Abstract:
Objective
We describe a detailed solution for maintaining high-capacity, data-intensive network flows (eg, 10, 40, 100 Gbps+) in a scientific, medical context while still adhering to security and privacy laws and regulations.
Materials and Methods
High-end networking, packet-filter firewalls, network intrusion-detection systems.
Results
We describe a âMedical Science DMZâ concept as an option for secure, high-volume transport of large, sensitive datasets between research institutions over national research networks, and give 3 detailed descriptions of implemented Medical Science DMZs.
Discussion
The exponentially increasing amounts of âomicsâ data, high-quality imaging, and other rapidly growing clinical datasets have resulted in the rise of biomedical research âBig Data.â The storage, analysis, and network resources required to process these data and integrate them into patient diagnoses and treatments have grown to scales that strain the capabilities of academic health centers. Some data are not generated locally and cannot be sustained locally, and shared data repositories such as those provided by the National Library of Medicine, the National Cancer Institute, and international partners such as the European Bioinformatics Institute are rapidly growing. The ability to store and compute using these data must therefore be addressed by a combination of local, national, and industry resources that exchange large datasets. Maintaining data-intensive flows that comply with the Health Insurance Portability and Accountability Act (HIPAA) and other regulations presents a new challenge for biomedical research. We describe a strategy that marries performance and security by borrowing from and redefining the concept of a Science DMZ, a framework that is used in physical sciences and engineering research to manage high-capacity data flows.
Conclusion
By implementing a Medical Science DMZ architecture, biomedical researchers can leverage the scale provided by high-performance computer and cloud storage facilities and national high-speed research networks while preserving privacy and meeting regulatory requirements
High throughput DNA sequencing to detect differences in the subgingival plaque microbiome in elderly subjects with and without dementia
BACKGROUND: To investigate the potential association between oral health and cognitive function, a pilot study was conducted to evaluate high throughput DNA sequencing of the V3 region of the 16S ribosomal RNA gene for determining the relative abundance of bacterial taxa in subgingival plaque from older adults with or without dementia. METHODS: Subgingival plaque samples were obtained from ten individuals at least 70âyears old who participated in a study to assess oral health and cognitive function. DNA was isolated from the samples and a gene segment from the V3 portion of the 16S bacterial ribosomal RNA gene was amplified and sequenced using an Illumina HiSeq1000 DNA sequencer. Bacterial populations found in the subgingival plaque were identified and assessed with respect to the cognitive status and oral health of the participants who provided the samples. RESULTS: More than two million high quality DNA sequences were obtained from each sample. Individuals differed greatly in the mix of phylotypes, but different sites from different subgingival depths in the same subject were usually similar. No consistent differences were observed in this small sample between subjects separated by levels of oral health, sex, or age; however a consistently higher level of Fusobacteriaceae and a generally lower level of Prevotellaceae was seen in subjects without dementia, although the difference did not reach statistical significance, possibly because of the small sample size. CONCLUSIONS: The results from this pilot study provide suggestive evidence that alterations in the subgingival microbiome are associated with changes in cognitive function, and provide support for an expanded analysis of the role of the oral microbiome in dementia
Temporal variation in spider trophic interactions is explained by the influence of weather on prey communities, web building and prey choice
1. Generalist invertebrate predators are sensitive to weather conditions, but the relationship between their trophic interactions and weather is poorly understood. This study investigates how weather affects the identity and frequency of spider trophic interactions over time, alongside prey community structure, web characteristics and prey choice.
2. Spiders (Linyphiidae and Lycosidae) and their prey were collected from barley fields in Wales, UK from April to September 2017-2018. The gut contents of 300 spiders were screened using DNA metabarcoding, analysed via multivariate models, and compared against prey availability using null models. When linyphiids were collected from webs, the height and area of webs were recorded and compared against weather conditions.
3. Trophic interactions changed over time and with weather conditions, primarily related to concomitant changes in prey communities. Spiders did, however, appear to mitigate the effects of structural changes in prey communities through changing prey preferences according to prevailing weather conditions, possibly facilitated by adaptive web construction.
4. Using these findings, we demonstrate that prey choice data collected under different weather conditions can be used to refine inter-annual predictions of spider trophic interactions, although prey abundance was secondary to diversity in driving the diet of these spiders. By improving our understanding of the interaction between trophic interactions and weather, we can better predict how ecological networks are likely to change over time in response to variation in weather conditions and, more urgently, global climate change
Overcoming the pitfalls of merging dietary metabarcoding into ecological networks
The construction of increasingly detailed species interaction networks is extending the potential applications of network ecology, providing an opportunity to understand complex eco-evolutionary interactions, ecosystem service provision and the impacts of environmental change on ecosystem functioning. Dietary metabarcoding is a rapidly growing tool increasingly used to construct ecological networks of trophic interactions, enabling the determination of individual animal diets including difficult-to-distinguish prey taxa and even for species where traditional dietary analyses are unsuitable (e.g. fluid feeders and small invertebrates).
Several challenges, however, surround the use of dietary metabarcoding, especially when metabarcoding-based interactions are merged with observation-based species interaction data.
We describe the difficulties surrounding the quantification of species interactions, sampling perspective discrepancy (i.e. zoocentric vs. phytocentric sampling), experimental biases, reference database omissions and assumptions regarding direct and indirect consumption events.
These problems are not, however, insurmountable. Effective experimental design and data curation with appropriate attention paid to these problems renders the incorporation of dietary metabarcoding into ecological network analysis a powerful tool for the construction of highly resolved networks. Throughout, we discuss how these problems should be addressed when merging data to construct ecological networks
Effectiveness of early compared with conservative rehabilitation for patients having rotator cuff repair surgery: an overview of systematic reviews
Aim/objective
The aim is to critically analyse and discuss the current literature and determine the effectiveness of ehabilitation for patients after surgical repair of rotator cuff tears for range of motion (ROM), pain, functional status and retear rates; in addition, an update of new literature is included.
Design
Overview of systematic reviews.
Data sources
A search was performed with no restrictions to date of publication and language in the following databases: EBSCO, AMED, CINAHL, SPORTDiscus, EMBASE, Cochrane, LILACS, MEDLINE, PEDro, Scielo, SCOPUS and Web of Knowledge. The PRISMA guideline was followed to develop this review and the R-AMSTAR tool was used for critical appraisal of included reviews.
Eligibility criteria
Only systematic reviews and randomised controlled trials (RCTs) comparing the effectiveness of early with conservative rehabilitation, after surgical repair of the rotator cuff, were included. Moreover, the studies should report ROM, pain, functional status and/or retears rates before and after 3â24 months of the surgery.
Results
10 systematic reviews and 11 RCTs were included for the final analysis. Conflicting results and conclusions were presented by the systematic reviews, the use of primary studies varied; also the methodological quality of the reviews was diverse. This updated review, with new meta-analysis, showed no difference for function, pain, ROM or retears ratio between early and conservative rehabilitation.
Summary/Conclusions
Early mobilisation may be beneficial, particularly for small and medium tears; however, more studies with higher quality are required, especially for patients with large tears who have been given less attention
The predator problem and PCR primers in molecular dietary analysis: Swamped or silenced; depth or breadth?
Dietary metabarcoding has vastly improved our ability to analyse the diets of animals, but it is hampered by a plethora of technical limitations including potentially reduced data output due to the disproportionate amplification of the DNA of the focal predator, here termed âthe predator problemâ. We review the various methods commonly used to overcome this problem, from deeper sequencing to exclusion of predator DNA during PCR, and how they may interfere with increasingly common multipredatorâtaxon studies. We suggest that multiprimer approaches with an emphasis on achieving both depth and breadth of prey detections may overcome the issue to some extent, although multitaxon studies require further consideration, as highlighted by an empirical example. We also review several alternative methods for reducing the prevalence of predator DNA that are conceptually promising but require additional empirical examination. The predator problem is a key constraint on molecular dietary analyses but, through this synthesis, we hope to guide researchers in overcoming this in an effective and pragmatic way
The predator problem and PCR primers in molecular dietary analysis: Swamped or silenced; depth or breadth?
Dietary metabarcoding has vastly improved our ability to analyse the diets of animals, but it is hampered by a plethora of technical limitations including potentially reduced data output due to the disproportionate amplification of the DNA of the focal predator, here termed âthe predator problemâ. We review the various methods commonly used to overcome this problem, from deeper sequencing to exclusion of predator DNA during PCR, and how they may interfere with increasingly common multipredatorâtaxon studies. We suggest that multiprimer approaches with an emphasis on achieving both depth and breadth of prey detections may overcome the issue to some extent, although multitaxon studies require further consideration, as highlighted by an empirical example. We also review several alternative methods for reducing the prevalence of predator DNA that are conceptually promising but require additional empirical examination. The predator problem is a key constraint on molecular dietary analyses but, through this synthesis, we hope to guide researchers in overcoming this in an effective and pragmatic way
Altered gut microbiota activate and expand insulin B15-23-Reactive CD8+ T-Cells
Insulin is a major autoantigen in type 1 diabetes, targeted by both CD8 and CD4 T-cells. We studied an insulin-reactive T-cell receptor (TCR) alpha-chain transgenic non-obese diabetic (NOD) mouse on a TCRCα and proinsulin2 (PI2)-deficient background, designated as A22Cα-/-PI2-/-NOD mice. These mice develop a low incidence of autoimmune diabetes. To test the role of gut microbiota on diabetes development in this model system, we treated the A22Cα-/-PI2-/-NOD mice with enrofloxacin, a broad-spectrum antibiotic. The treatment led to male mice developing accelerated diabetes. We found that enrofloxacin increased the frequency of the insulin-reactive CD8+ T-cells and activated the cells in the Peyerâs patches (PP) and pancreatic lymph nodes (PLNs), together with induction of immunological effects on the antigen-presenting cell populations. The composition of gut microbiota differed between the enrofloxacin-treated and untreated mice and also between the enrofloxacin-treated mice that developed diabetes, compared with those that remained normoglycemic. Our results provide evidence that the composition of the gut microbiota is important for determining the expansion and activation of insulin-reactive CD8+ T-cells
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