Combinatorial hydrogel library enables identification of materials that mitigate the foreign body response in primates

The foreign body response is an immune-mediated reaction that can lead to the failure of implanted medical devices and discomfort for the recipient. There is a critical need for biomaterials that overcome this key challenge in the development of medical devices. Here we use a combinatorial approach for covalent chemical modification to generate a large library of variants of one of the most widely used hydrogel biomaterials, alginate. We evaluated the materials in vivo and identified three triazole-containing analogs that substantially reduce foreign body reactions in both rodents and, for at least 6 months, in non-human primates. The distribution of the triazole modification creates a unique hydrogel surface that inhibits recognition by macrophages and fibrous deposition. In addition to the utility of the compounds reported here, our approach may enable the discovery of other materials that mitigate the foreign body response.Leona M. and Harry B. Helmsley Charitable Trust (3-SRA-2014-285-M-R)United States. National Institutes of Health (EB000244)United States. National Institutes of Health (EB000351)United States. National Institutes of Health (DE013023)United States. National Institutes of Health (CA151884)United States. National Institutes of Health (P41EB015871-27)National Cancer Institute (U.S.) (P30-CA14051

Genome fluctuations in cyanobacteria reflect evolutionary, developmental and adaptive traits

<p>Abstract</p> <p>Background</p> <p>Cyanobacteria belong to an ancient group of photosynthetic prokaryotes with pronounced variations in their cellular differentiation strategies, physiological capacities and choice of habitat. Sequencing efforts have shown that genomes within this phylum are equally diverse in terms of size and protein-coding capacity. To increase our understanding of genomic changes in the lineage, the genomes of 58 contemporary cyanobacteria were analysed for shared and unique orthologs.</p> <p>Results</p> <p>A total of 404 protein families, present in all cyanobacterial genomes, were identified. Two of these are unique to the phylum, corresponding to an AbrB family transcriptional regulator and a gene that escapes functional annotation although its genomic neighbourhood is conserved among the organisms examined. The evolution of cyanobacterial genome sizes involves a mix of gains and losses in the clade encompassing complex cyanobacteria, while a single event of reduction is evident in a clade dominated by unicellular cyanobacteria. Genome sizes and gene family copy numbers evolve at a higher rate in the former clade, and multi-copy genes were predominant in large genomes. Orthologs unique to cyanobacteria exhibiting specific characteristics, such as filament formation, heterocyst differentiation, diazotrophy and symbiotic competence, were also identified. An ancestral character reconstruction suggests that the most recent common ancestor of cyanobacteria had a genome size of approx. 4.5 Mbp and 1678 to 3291 protein-coding genes, 4%-6% of which are unique to cyanobacteria today.</p> <p>Conclusions</p> <p>The different rates of genome-size evolution and multi-copy gene abundance suggest two routes of genome development in the history of cyanobacteria. The expansion strategy is driven by gene-family enlargment and generates a broad adaptive potential; while the genome streamlining strategy imposes adaptations to highly specific niches, also reflected in their different functional capacities. A few genomes display extreme proliferation of non-coding nucleotides which is likely to be the result of initial expansion of genomes/gene copy number to gain adaptive potential, followed by a shift to a life-style in a highly specific niche (e.g. symbiosis). This transition results in redundancy of genes and gene families, leading to an increase in junk DNA and eventually to gene loss. A few orthologs can be correlated with specific phenotypes in cyanobacteria, such as filament formation and symbiotic competence; these constitute exciting exploratory targets.</p

Provider and lay perspectives on intra-uterine contraception: a global review

BACKGROUND: Intra-uterine contraception (IUC) involves the use of an intra-uterine device (IUD), a highly effective, long-acting, reversible contraceptive method. Historically, the popularity of IUC has waxed and waned across different world regions, due to policy choices and shifts in public opinion. However, despite its advantages and cost-effectiveness for programmes, IUC's contribution to contraceptive prevalence is currently negligible in many countries. This paper presents the results of a systematic review of the global literature on provider and lay perspectives on IUC. It aims to shed light on the reasons for low use of IUC and reflect on potential opportunities for the method's promotion. METHODS: A systematic search of the literature was conducted in four peer-reviewed journals and four electronic databases (MEDLINE, EMBASE, POPLINE, and Global Health). Screening resulted in the inclusion of 68 relevant publications. RESULTS: Most included studies were conducted in areas where IUD use is moderate or low. Findings are similar across these areas. Many providers have low or uneven levels of knowledge on IUC and limited training. Many wrongly believe that IUC entails serious side effects such as pelvic inflammatory disease (PID), and are reluctant to provide it to entire eligible categories, such as HIV-positive women. There is particular resistance to providing IUC to teenagers and nulliparae. Provider opinions may be more favourable towards the hormonal IUD. Some health-care providers choose IUC for themselves. Many members of the public have low knowledge and unfounded misconceptions about IUC, such as the fear of infertility. Some are concerned about the insertion and removal processes, and about its effect on menses. However, users of IUC are generally satisfied and report a number of benefits. Peers and providers exert a strong influence on women's attitudes. CONCLUSION: Both providers and lay people have inaccurate knowledge and misconceptions about IUC, which contribute to explaining its low use. However, many reported concerns and fears could be alleviated through correct information. Concerted efforts to train providers, combined with demand creation initiatives, could therefore boost the method's popularity. Further research is needed on provider and lay perspectives on IUDs in low- and middle-income countries

Intraductal Papillary Mucinous Neoplasms of the Pancreas : A Nationwide Registry-Based Study

Background and Aims: To investigate the paraclinical and pathological features of surgically resected intraductal papillary mucinous neoplasms in Sweden. Materials and Methods: A review of prospectively collected data on patients undergoing pancreatic resection for a histopathologically verified intraductal papillary mucinous neoplasm between 2010 and 2016 was performed using the Swedish National Registry for Pancreatic and Periampullary Cancer. Results: A total of 3038 pancreatic resections were performed during the study period, of which 251 (8.3%) were due to intraductal papillary mucinous neoplasms. The intraductal papillary mucinous neoplasm cases comprised 227 noninvasive and 24 invasive lesions. There was an annual increase in the number of resected intraductal papillary mucinous neoplasms, from 13 in 2010 to 56 in 2016, and an increase in the proportion of intraductal papillary mucinous neoplasm to the total number of pancreatic resections (4.7%–11%). Biliary obstruction was the only independent predictor of invasive disease, with odds ratio 3.106 (p = 0.030). There was no difference in survival between low-, intermediate-, and high-grade dysplastic lesions (p = 0.417). However, once invasive, the prognosis was severely impacted (p < 0.001). Three-year survival was 90% for noninvasive intraductal papillary mucinous neoplasm and 39% for invasive intraductal papillary mucinous neoplasm. Survival was better in lymph node negative invasive intraductal papillary mucinous neoplasm (p = 0.021), but still dismal compared to noninvasive lesions (p < 0.001). Conclusion: The number of surgically resected intraductal papillary mucinous neoplasms is increasing in Sweden. Biliary obstruction is associated with invasive disease. Low-to-high-grade dysplastic intraductal papillary mucinous neoplasm has an excellent prognosis, while invasive intraductal papillary mucinous neoplasm has a poor survival rate

Multicentre study of multidisciplinary team assessment of pancreatic cancer resectability and treatment allocation

Background: Multidisciplinary team (MDT) meetings have been adopted widely to ensure optimal treatment for patients with cancer. Agreements in tumour staging, resectability assessments and treatment allocation between different MDTs were assessed. Methods: Of all patients referred to one hospital, 19 patients considered to have non-metastatic pancreatic cancer for evaluation were selected randomly for a multicentre study of MDT decisions in seven units across Northern Europe. Anonymized clinical information and radiological images were disseminated to theMDTs. All patients were reviewed by theMDTs for radiological T, N andMcategory, resectability assessment and treatment allocation. Each MDT was blinded to the decisions of other teams. Agreements were expressed as raw percentages and Krippendorff's.. values, both with 95 per cent confidence intervals. Results: A total of 132 evaluations in 19 patients were carried out by the seven MDTs (1 evaluation was excluded owing to technical problems). The level of agreement for T, N and M categories ranged from moderate to near perfect (46.8, 61.1 and 82.8 per cent respectively), but there was substantial variation in assessment of resectability; seven patients were considered to be resectable by one MDT but unresectable by another. The MDTs all agreed on either a curative or palliative strategy in less than half of the patients (9 of 19). Only fair agreement in treatment allocation was observed (Krippendorff's.. 0.31, 95 per cent c. i. 0.16 to 0.45). There was a high level of agreement in treatment allocation where resectability assessments were concordant. Conclusion: Considerable disparities in MDT evaluations of patients with pancreatic cancer exist, including substantial variation in resectability assessments