Recognition and blocking of innate immunity cells by Candida albicans chitin

Peer reviewedPublisher PD

Haemoglobin, anaemia, dementia and cognitive decline in the elderly, a systematic review

<p>Abstract</p> <p>Background</p> <p>Anaemia may increase risk of dementia or cognitive decline. There is also evidence that high haemoglobin levels increase risk of stroke, and consequently possible cognitive impairment. The elderly are more at risk of developing dementia and are also more likely to suffer from anaemia, although there is relatively little longitudinal literature addressing this association.</p> <p>Methods</p> <p>To evaluate the evidence for any relationship between incident cognitive decline or dementia in the elderly and anaemia or haemoglobin level, we conducted a systematic review and meta-analyses of peer reviewed publications. Medline, Embase and PsychInfo were searched for English language publications between 1996 and 2006. Criteria for inclusion were longitudinal studies of subjects aged ≥65, with primary outcomes of incident dementia or cognitive decline. Other designs were excluded.</p> <p>Results</p> <p>Three papers were identified and only two were able to be combined into a meta-analysis. The pooled hazard ratio for these two studies was 1.94 (95 percent confidence intervals of 1.32–2.87) showing a significantly increased risk of incident dementia with anaemia. It was not possible to investigate the effect of higher levels of haemoglobin.</p> <p>Conclusion</p> <p>Anaemia is one factor to bear in mind when evaluating risk of incident dementia. However, there are few data available and the studies were methodologically varied so a cautionary note needs to be sounded and our primary recommendation is that further robust research be carried out.</p

High prevalence of chitotriosidase deficiency in Peruvian Amerindians exposed to chitin-bearing food and enteroparasites

The human genome encodes a gene for an enzymatically active chitinase (CHIT1) located in a single copy on Chromosome 1, which is highly expressed by activated macrophages and in other cells of the innate immune response. Several dysfunctional mutations are known in CHIT1, including a 24-bp duplication in Exon 10 causing catalytic deficiency. This duplication is a common variant conserved in many human populations, except in West and South Africans. Thus it has been proposed that human migration out of Africa and the consequent reduction of exposure to chitin from environmental factors may have enabled the conservation of dysfunctional mutations in human chitinases. Our data obtained from 85 indigenous Amerindians from Peru, representative of populations characterized by high prevalence of chitin-bearing enteroparasites and intense entomophagy, reveal a very high frequency of the 24-bp duplication (47.06%), and of other single nucleotide polymorphisms which are known to partially affect enzymatic activity (G102S: 42.7% and A442G/V: 25.5%). Our finding is in line with a founder effect, but appears to confute our previous hypothesis of a protective role against parasite infection and sustains the discussion on the redundancy of chitinolytic function

Effect of the ultrastructure of chitosan nanoparticles in colloidal stability, quorum quenching and antibacterial activities

We have fabricated two types of crosslinked chitosan-based nanoparticles (NPs), namely (1) ionically crosslinked with tripolyphosphate (TPP), designated as IC-NPs and (2) dually co-crosslinked (ionically and covalently with TPP and genipin, respectively) termed CC-NPs. The two types of NPs were physichochemically characterized by means of DLS-NIBS, synchrotron SAXS and M3-PALS (zeta potential). First, we found that covalent co-crosslinking of ionically pre-crosslinked nanoparticles yielded monodisperse CC-NPs in the size range of ∼200 nm, whereas the parental IC-NPs remained highly polydisperse. While both types of chitosan nanoparticles displayed a core-shell structure, as determined by synchrotron SAXS, only the structure of CC-NPs remained stable at long incubation times. This enhanced structural robustness of CC-NPs was likely responsible of their superior colloidal stability even in biological medium. Second, we explored the antimicrobial and quorum sensing inhibition activity of both types of nanoparticles. We found that CC-NPs had lower long-term toxicity than IC-NPs. In contrast, sub-lethal doses of IC-NPs consistently displayed higher levels of quorum quenching activity than CC-NPs. Thus, this work underscores the influence of the NP’s ultrastructure on their colloidal and biological properties. While the cellular and molecular mechanisms at play are yet to be fully elucidated, our results broaden the spectrum of use of chitosan-based nanobiomaterialsin the development of antibiotic-free approaches against Gram-negative pathogenic bacteria

Supercritical fluid technology as a tool to prepare gradient multifunctional architectures towards regeneration of osteochondral injuries

Platelet lysates (PLs) are a natural source of growth factors (GFs) known for its stimulatory role on stem cells which can be obtained after activation of platelets from blood plasma. The possibility to use PLs as growth factor source for tissue healing and regeneration has been pursued following different strategies. Platelet lysates are an enriched pool of growth factors which can be used as either a GFs source or as a three-dimensional (3D) hydrogel. However, most of current PLs-based hydrogels lack stability, exhibiting significant shrinking behavior. This chapter focuses on the application of supercritical fluid technology to develop three-dimensional architectures of PL constructs, crosslinked with genipin. The proposed technology allows in a single step operation the development of mechanically stable porous structures, through chemical crosslinking of the growth factors present in the PL pool, followed by supercritical drying of the samples. Furthermore gradient structures of PL-based structures with bioactive glass are also presented and are described as an interesting approach to the treatment of osteochondral defects.info:eu-repo/semantics/publishedVersio

Anemia status, hemoglobin concentration and outcome after acute stroke: a cohort study

<p>Abstract</p> <p>Background</p> <p>In the setting of an acute stroke, anemia has the potential to worsen brain ischemia, however, the relationship between the entire range of hemoglobin to long-term outcome is not well understood.</p> <p>Methods</p> <p>We examined the association between World Health Organization-defined admission anemia status (hemoglobin<13 in males, <12 g/dl in women) and hemoglobin concentration and 1-year outcome among 859 consecutive patients with acute stroke (ischemic or intracerebral hemorrhage).</p> <p>Results</p> <p>The mean baseline hemoglobin concentration was 13.8 ± 1.7 g/dl (range 8.1 - 18.7). WHO-defined anemia was present in 19% of patients among both women and men. After adjustment for differences in baseline characteristics, patients with admission anemia had an adjusted OR for all-cause death at 1-month of 1.90 (95% CI, 1.05 to 3.43) and at 1-year of 1.72 (95% CI, 1.00 to 2.93) and for the combined end-point of disability, nursing facility care or death of 2.09 (95% CI, 1.13 to 3.84) and 1.83 (95% CI, 1.02 to 3.27) respectively. The relationship between hemoglobin quartiles and all-cause death revealed a non-linear association with increased risk at extremes of both low and high concentrations. In logistic regression models developed to estimate the linear and quadratic relation between hemoglobin and outcomes of interest, each unit increment in hemoglobin squared was associated with increased adjusted odds of all-cause death [at 1-month 1.06 (1.01 to 1.12; p = 0.03); at 1-year 1.09 (1.04 to 1.15; p < 0.01)], confirming that extremes of both low and high levels of hemoglobin were associated with increased mortality.</p> <p>Conclusions</p> <p>WHO-defined anemia was common in both men and women among patients with acute stroke and predicted poor outcome. Moreover, the association between admission hemoglobin and mortality was not linear; risk for death increased at both extremes of hemoglobin.</p

Fabrication and characterization of Eri silk fibers-based sponges for biomedical application

Cocoon-derived semi-domesticated Eri silk fibers still lack exploitation for tissue engineering applications due to their poor solubility using conventional methods. The present work explores the ability to process cocoon fibers of non-mulberry Eri silk (Samia/Philosamia ricini) into sponges through a green approach using ionic liquid (IL) â 1-buthyl-imidazolium acetate as a solvent. The formation of β-sheet structures during Eri silk/IL gelation was acquired by exposing the Eri silk/IL gels to a saturated atmosphere composed of two different solvents: (i) isopropanol/ethanol (physical stabilization) and (ii) genipin, a natural crosslinker, dissolved in ethanol (chemical crosslinking). The sponges were then obtained by freeze-drying. This approach promotes the formation of both stable and ordered non-crosslinked Eri silk fibroin matrices. Moreover, genipin-crosslinked silk fibroin sponges presenting high height recovery capacity after compression, high swelling degree and suitable mechanical properties for tissue engineering applications were produced. The incorporation of a model drug â ibuprofen â and the corresponding release study from the loaded sponges demonstrated the potential of using these matrices as effective drug delivery systems. The assessment of the biological performance of ATDC5 chondrocyte-like cells in contact with the developed sponges showed the promotion of cell adhesion and proliferation, as well as extracellular matrix production within two weeks of culture. Spongesâ intrinsic properties and biological findings open up their potential use for biomedical applications.The authors SSS, DSC, MBO, NMO acknowledge financial support from Portuguese Foundation for Science and Technology – FCT (Grants SFRH/BPD/45307/2008, SFRH/BPD/85790/2012, SFRH/BD/71396/2010 and SFRH/BD/73172/2010, respectively), ‘‘Fundo Social Europeu” – FSE, and ‘‘Programa Diferencial de Potencial Humano POPH”. This work is also financially supported by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n REGPOT-CT2012-316331-POLARIS and from Fundação para a Ciência e Tecnologia (FCT) through the project ENIGMA – PTDC/EQU-EPR/121491/2010. The laboratory work of SCK is supported by Department of Biotechnology and Indian Council of Medical Research, Govt of India. SCK and RLR acknowledge their short visits either Institutes. SCK is also grateful to 3B´ s Research Group- Biomaterials, Biodegradables and Biomimetics, University of Minho, Portugal for providing facilities during his short visit

Using Administrative Mental Health Indicators in Heart Failure Outcomes Research: Comparison of Clinical Records and International Classification of Disease Coding

BackgroundUse of mental indication in health outcomes research is of growing interest to researchers. This study, as part of a larger research program, quantified agreement between administrative International Classification of Disease (ICD-9) coding for, and "gold standard" clinician documentation of, mental health issues (MHIs) in hospitalized heart failure (HF) patients to determine the validity of mental health administrative data for use in HF outcomes research.MethodsA 13% random sample (n = 504) was selected from all unique patients (n = 3,769) hospitalized with a primary HF diagnosis at 4 San Diego County community hospitals during 2009-2012. MHI was defined as ICD-9 discharge diagnostic coding 290-319. Records were audited for clinician documentation of MHI.ResultsA total of 43% (n = 216) had mental health clinician documentation; 33% (n = 164) had ICD-9 coding for MHI. ICD-9 code bundle 290-319 had 0.70 sensitivity, 0.97 specificity, and kappa 0.69 (95% confidence interval 0.61-0.79). More specific ICD-9 MHI code bundles had kappas ranging from 0.44 to 0.82 and sensitivities ranging from 42% to 82%.ConclusionsAgreement between ICD-9 coding and clinician documentation for a broadly defined MHI is substantial, and can validly "rule in" MHI for hospitalized patients with heart failure. More specific MHI code bundles had fair to almost perfect agreement, with a wide range of sensitivities for identifying patients with an MHI

Toward osteogenic differentiation of marrow stromal cells and in vitro production of mineralized extracellular matrix onto natural scaffolds

Uncorrected proofTissue engineering has emerged as a new interdisciplinary field for the repair of various tissues, restoring their functions by using scaffolds, cells, and/or bioactive factors. A temporary scaffold acts as an extracellular matrix analog to culture cells and guide the development of new tissue. In this chapter, we discuss the preparation of naturally derived scaffolds of polysaccharide origin, the osteogenic differentiation of mesenchymal stem cells cultured on biomimetic calcium phosphate coatings, and the delivery of biomolecules associated with extracellular matrix mineralization