408 research outputs found

    Vernix caseosa as a multi-component defence system based on polypeptides, lipids and their interactions

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldVernix caseosa is a white cream-like substance that covers the skin of the foetus and the newborn baby. Recently, we discovered antimicrobial peptides/proteins such as LL-37 in vernix, suggesting host defence functions of vernix. In a proteomic approach, we have continued to characterize proteins in vernix and have identified 20 proteins, plus additional variant forms. The novel proteins identified, considered to be involved in host defence, are cystatin A, UGRP-1, and calgranulin A, B and C. These proteins add protective functions to vernix such as antifungal activity, opsonizing capacity, protease inhibition and parasite inactivation. The composition of the lipids in vernix has also been characterized and among these compounds the free fatty acids were found to exhibit antimicrobial activity. Interestingly, the vernix lipids enhance the antimicrobial activity of LL-37 in vitro, indicating interactions between lipids and antimicrobial peptides in vernix. In conclusion, vernix is a balanced cream of compounds involved in host defence, protecting the foetus and newborn against infection

    Bile acid biosynthesis in Smith-Lemli-Opitz syndrome bypassing cholesterol: Potential importance of pathway intermediates

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    Bile acids are the end products of cholesterol metabolism secreted into bile. They are essential for the absorption of lipids and lipid soluble compounds from the intestine. Here we have identified a series of unusual Δ5-unsaturated bile acids in plasma and urine of patients with Smith-Lemli-Opitz syndrome (SLOS), a defect in cholesterol biosynthesis resulting in elevated levels of 7-dehydrocholesterol (7-DHC), an immediate precursor of cholesterol. Using liquid chromatography – mass spectrometry (LC-MS) we have uncovered a pathway of bile acid biosynthesis in SLOS avoiding cholesterol starting with 7-DHC and proceeding through 7-oxo and 7β-hydroxy intermediates. This pathway also occurs to a minor extent in healthy humans, but elevated levels of pathway intermediates could be responsible for some of the features SLOS. The pathway is also active in SLOS affected pregnancies as revealed by analysis of amniotic fluid. Importantly, intermediates in the pathway, 25-hydroxy-7-oxocholesterol, (25R)26-hydroxy-7-oxocholesterol, 3β-hydroxy-7-oxocholest-5-en-(25R)26-oic acid and the analogous 7β-hydroxysterols are modulators of the activity of Smoothened (Smo), an oncoprotein that mediates Hedgehog (Hh) signalling across membranes during embryogenesis and in the regeneration of postembryonic tissue. Computational docking of the 7-oxo and 7β-hydroxy compounds to the extracellular cysteine rich domain of Smo reveals that they bind in the same groove as both 20S-hydroxycholesterol and cholesterol, known activators of the Hh pathway

    Surviving rectal cancer at the cost of a colostomy: global survey of long-term health-related quality of life in 10 countries

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    Background Colorectal cancer management may require an ostomy formation; however, a stoma may negatively impact health-related quality of life (HRQoL). This study aimed to compare generic and stoma-specific HRQoL in patients with a permanent colostomy after rectal cancer across different countries. Method A cross-sectional cohorts of patients with a colostomy after rectal cancer in Denmark, Sweden, Spain, the Netherlands, China, Portugal, Australia, Lithuania, Egypt, and Israel were invited to complete questionnaires regarding demographic and socioeconomic factors along with the Colostomy Impact (CI) score, European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) and five anchor questions assessing colostomy impact on HRQoL. The background characteristics of the cohorts from each country were compared and generic HRQoL was measured with the EORTC QLQ-C30 presented for the total cohort. Results were compared with normative data of reference European populations. The predictors of reduced HRQoL were investigated by multivariable logistic regression, including demographic and socioeconomic factors and stoma-related problems. Results A total of 2557 patients were included. Response rates varied between 51-93 per cent. Mean time from stoma creation was 2.5-6.2 (range 1.1-39.2) years. A total of 25.8 per cent of patients reported that their colostomy impairs their HRQoL 'some'/'a lot'. This group had significantly unfavourable scores across all EORTC subscales compared with patients reporting 'no'/'a little' impaired HRQoL. Generic HRQoL differed significantly between countries, but resembled the HRQoL of reference populations. Multivariable logistic regression showed that stoma dysfunction, including high CI score (OR 3.32), financial burden from the stoma (OR 1.98), unemployment (OR 2.74), being single/widowed (OR 1.35) and young age (OR 1.01 per year) predicted reduced stoma-related HRQoL. Conclusion Overall HRQoL is preserved in patients with a colostomy after rectal cancer, but a quarter of the patients interviewed reported impaired HRQoL. Differences among several countries were reported and socioeconomic factors correlated with reduced quality of life. In this global survey among 2557 individuals with a colostomy after rectal cancer, generic and stoma-specific HRQoL differed significantly between countries; however, it resembled that of country-specific population norms. The most important predictors of stoma-related reduced HRQoL were stoma dysfunction and being financially burdened by the colostomy

    Macrophage and dendritic cell subsets in IBD: ALDH<sup>+</sup> cells are reduced in colon tissue of patients with ulcerative colitis regardless of inflammation

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    Disruption of the homeostatic balance of intestinal dendritic cells (DCs) and macrophages (MQs) may contribute to inflammatory bowel disease. We characterized DC and MQ populations, including their ability to produce retinoic acid, in clinical material encompassing Crohn's ileitis, Crohn's colitis and ulcerative colitis (UC) as well as mesenteric lymph nodes (MLNs) draining these sites. Increased CD14(+)DR(int) MQs characterized inflamed intestinal mucosa while total CD141(+) or CD1c(+) DCs numbers were unchanged. However, CD103(+) DCs, including CD141(+)CD103(+) and CD1c(+)CD103(+) DCs, were reduced in inflamed intestine. In MLNs, two CD14(-) DC populations were identified: CD11c(int)HLADR(hi) and CD11c(hi)HLADR(int) cells. A marked increase of CD11c(hi)HLADR(int) DC, particularly DR(int)CD1c(+) DCs, characterized MLNs draining inflamed intestine. The fraction of DC and MQ populations expressing aldehyde dehydrogenase (ALDH) activity, reflecting retinoic acid synthesis, in UC colon, both in active disease and remission, were reduced compared to controls and inflamed Crohn's colon. In contrast, no difference in the frequency of ALDH(+) cells among blood precursors was detected between UC patients and non-inflamed controls. This suggests that ALDH activity in myeloid cells in the colon of UC patients, regardless of whether the disease is active or in remission, is influenced by the intestinal environment.Mucosal Immunology advance online publication, 17 June 2015; doi:10.1038/mi.2015.48

    Metabolic Effects of n-3 PUFA as Phospholipids Are Superior to Triglycerides in Mice Fed a High-Fat Diet: Possible Role of Endocannabinoids

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    Background n-3 polyunsaturated fatty acids, namely docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), reduce the risk of cardiovascular disease and can ameliorate many of obesity-associated disorders. We hypothesised that the latter effect will be more pronounced when DHA/EPA is supplemented as phospholipids rather than as triglycerides. Methodology/Principal Findings In a ‘prevention study’, C57BL/6J mice were fed for 9 weeks on either a corn oil-based high-fat obesogenic diet (cHF; lipids ~35% wt/wt), or cHF-based diets in which corn oil was partially replaced by DHA/EPA, admixed either as phospholipids or triglycerides from marine fish. The reversal of obesity was studied in mice subjected to the preceding cHF-feeding for 4 months. DHA/EPA administered as phospholipids prevented glucose intolerance and tended to reduce obesity better than triglycerides. Lipemia and hepatosteatosis were suppressed more in response to dietary phospholipids, in correlation with better bioavailability of DHA and EPA, and a higher DHA accumulation in the liver, white adipose tissue (WAT), and muscle phospholipids. In dietary obese mice, both DHA/EPA concentrates prevented a further weight gain, reduced plasma lipid levels to a similar extent, and tended to improve glucose tolerance. Importantly, only the phospholipid form reduced plasma insulin and adipocyte hypertrophy, while being more effective in reducing hepatic steatosis and low-grade inflammation of WAT. These beneficial effects were correlated with changes of endocannabinoid metabolome in WAT, where phospholipids reduced 2-arachidonoylglycerol, and were more effective in increasing anti-inflammatory lipids such as N-docosahexaenoylethanolamine. Conclusions/Significance Compared with triglycerides, dietary DHA/EPA administered as phospholipids are superior in preserving a healthy metabolic profile under obesogenic conditions, possibly reflecting better bioavalability and improved modulation of the endocannabinoid system activity in WA

    New methods for analysis of oxysterols and related compounds by LC–MS

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    Oxysterols are oxygenated forms of cholesterol or its precursors. They are formed enzymatically and via reactive oxygen species. Oxysterols are intermediates in bile acid and steroid hormone biosynthetic pathways and are also bioactive molecules in their own right, being ligands to nuclear receptors and also regulators of the processing of steroid regulatory element-binding proteins (SREBPs) to their active forms as transcription factors regulating cholesterol and fatty acid biosynthesis. Oxysterols are implicated in the pathogenesis of multiple disease states ranging from atherosclerosis and cancer to multiple sclerosis and other neurodegenerative diseases including Alzheimer’s and Parkinson’s disease. Analysis of oxysterols is challenging on account of their low abundance in biological systems in comparison to cholesterol, and due to the propensity of cholesterol to undergo oxidation in air to generate oxysterols with the same structures as those present endogenously. In this article we review the mass spectrometry-based methods for oxysterol analysis paying particular attention to analysis by liquid chromatography – mass spectrometry (LC-MS)

    A new tool to assess Clinical Diversity In Meta‐analyses (CDIM) of interventions

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    OBJECTIVE: To develop and validate Clinical Diversity In Meta-analyses (CDIM), a new tool for assessing clinical diversity between trials in meta-analyses of interventions.STUDY DESIGN AND SETTING: The development of CDIM was based on consensus work informed by empirical literature and expertise. We drafted the CDIM tool, refined it, and validated CDIM for interrater scale reliability and agreement in three groups.RESULTS: CDIM measures clinical diversity on a scale that includes four domains with 11 items overall: setting (time of conduct/country development status/units type); population (age, sex, patient inclusion criteria/baseline disease severity, comorbidities); interventions (intervention intensity/strength/duration of intervention, timing, control intervention, cointerventions); and outcome (definition of outcome, timing of outcome assessment). The CDIM is completed in two steps: first two authors independently assess clinical diversity in the four domains. Second, after agreeing upon scores of individual items a consensus score is achieved. Interrater scale reliability and agreement ranged from moderate to almost perfect depending on the type of raters.CONCLUSION: CDIM is the first tool developed for assessing clinical diversity in meta-analyses of interventions. We found CDIM to be a reliable tool for assessing clinical diversity among trials in meta-analysis.</p
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