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- Caramori, G, et al.
(författare)
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Mucin expression in peripheral airways of patients with chronic obstructive pulmonary disease
- 2004
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Ingår i: Histopathology. - : Wiley. - 0309-0167 .- 1365-2559. ; 45:5, s. 477-484
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To study the expression of mucins in peripheral airways in patients with chronic obstructive pulmonary disease (COPD). Methods and results: Peripheral lung sections from smokers with COPD (n = 9) and age-matched controls including smokers (n = 11) and lifelong non-smokers with normal lung function (n = 6) were stained with alcian blue, periodic acid-Schiff (PAS) and by immunohistochemistry of mucins (MUC): MUC2, MUC4, MUC5AC, MUC5B and MUC6. Histochemical staining and immunoreactivity of bronchiolar epithelium were graded and the presence or absence of stained mucus in the bronchiolar lumen was evaluated. There were no differences in alcian blue and PAS epithelial staining between the three groups. Intraluminal PAS staining was significantly more frequent among COPD subjects (P < 0.05). The expression of MUC5AC was significantly higher in the bronchiolar epithelium of patients with COPD (P < 0.05). Within the bronchiolar lumen, the predominant mucin was MUC5B. Intraluminal MUC5B was significantly more frequent among COPD patients (P < 0.05). Conclusions: COPD is specifically associated with increased expression of MUC5B in the bronchiolar lumen and of the mucin MUC5AC in the bronchiolar epithelium. These changes in mucin production in the peripheral airways may contribute to the pathophysiology of COPD.
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- Carlstedt, I, et al.
(författare)
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Characterization of two different glycosylated domains from the insoluble mucin complex of rat small intestine.
- 1993
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Ingår i: The Journal of biological chemistry. - 0021-9258. ; 268:25, s. 18771-81
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Tidskriftsartikel (refereegranskat)abstract
- The highly glycosylated domains of rat small intestinal mucins were isolated after reduction and trypsin digestion and separated into two populations (A and B) by gel chromatography. The molecular mass values were 650 and 335 kDa, respectively, and the relative yields suggest that the two glycopeptides occur in equimolar proportions. Electron microscopy revealed linear structures with weight average lengths of 230 nm (A) and 110 nm (B) corresponding to a mass/unit length of about 3 kDa/nm. The protein cores (17-19%) contain large amounts of threonine (over 40%), serine (17-24%), and proline (18-19%). Carbohydrate and sulfate account for approximately 80 and 0.5%, respectively, and gas chromatography-mass spectrometry showed that the patterns of neutral and sialic acid-containing glycans are very similar in the two glycopeptides. Both contain a significant amount (7-10 mol %) of single GalNAc residues, the average oligosaccharide is about 4 sugar residues long, and the largest species observed are heptasaccharides. The major neutral and sialic acid-containing oligosaccharides are Fuc1-2Gal1-3GalNAcol and GlcNAc1-6(NeuGc2-Gal1-3)GalNAcol, respectively. Sialic acid is present as both N-acetyl- and N-glycoloyl-neuraminic acid. Repeated extractions of the tissue with guanidinium chloride left approximately 80% of the mucus glycoproteins as an insoluble glycoprotein complex whereas exposure to dithiothreitol or high speed homogenization accomplished complete solubilization. The "subunits" obtained after reduction with dithiothreitol are larger than glycopeptides A and B, and fragments corresponding in size to the latter are obtained after cleavage with trypsin. Most of the mucins from rat small intestine thus occurs as an insoluble glycoprotein complex composed of subunits joined with disulfide bonds. The subunits contain two highly glycosylated regions with different lengths substituted with very similar oligosaccharides.
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- Kononowicz, Andrzej A., et al.
(författare)
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Virtual Patient Simulations in Health Professions Education : Systematic Review and Meta-Analysis by the Digital Health Education Collaboration
- 2019
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Ingår i: Journal of Medical Internet Research. - : JMIR Publications. - 1438-8871. ; 21:7
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Forskningsöversikt (refereegranskat)abstract
- Background: Virtual patients are interactive digital simulations of clinical scenarios for the purpose of health professions education. There is no current collated evidence on the effectiveness of this form of education.Objective: The goal of this study was to evaluate the effectiveness of virtual patients compared with traditional education, blended with traditional education, compared with other types of digital education, and design variants of virtual patients in health professions education. The outcomes of interest were knowledge, skills, attitudes, and satisfaction.Methods: We performed a systematic review on the effectiveness of virtual patient simulations in pre- and postregistration health professions education following Cochrane methodology. We searched 7 databases from the year 1990 up to September 2018. No language restrictions were applied. We included randomized controlled trials and cluster randomized trials. We independently selected studies, extracted data, and assessed risk of bias and then compared the information in pairs. We contacted study authors for additional information if necessary. All pooled analyses were based on random-effects models.Results: A total of 51 trials involving 4696 participants met our inclusion criteria. Furthermore, 25 studies compared virtual patients with traditional education, 11 studies investigated virtual patients as blended learning, 5 studies compared virtual patients with different forms of digital education, and 10 studies compared different design variants. The pooled analysis of studies comparing the effect of virtual patients to traditional education showed similar results for knowledge (standardized mean difference [SMD]=0.11, 95% CI -0.17 to 0.39, I-2=74%, n=927) and favored virtual patients for skills (SMD=0.90, 95% CI 0.49 to 1.32, I-2=88%, n=897). Studies measuring attitudes and satisfaction predominantly used surveys with item-by-item comparison. Trials comparing virtual patients with different forms of digital education and design variants were not numerous enough to give clear recommendations. Several methodological limitations in the included studies and heterogeneity contributed to a generally low quality of evidence.Conclusions: Low to modest and mixed evidence suggests that when compared with traditional education, virtual patients can more effectively improve skills, and at least as effectively improve knowledge. The skills that improved were clinical reasoning, procedural skills, and a mix of procedural and team skills. We found evidence of effectiveness in both high-income and low-and middle-income countries, demonstrating the global applicability of virtual patients. Further research should explore the utility of different design variants of virtual patients.
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- Semino-Mora, C, et al.
(författare)
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Intracellular and interstitial expression of Helicobacter pylori virulence genes in gastric precancerous intestinal metaplasia and adenocarcinoma
- 2003
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Ingår i: Journal of Infectious Diseases. - 1537-6613. ; 187:8, s. 1165-1177
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Tidskriftsartikel (refereegranskat)abstract
- Gastric intestinal metaplasia (IM) and gastric cancer are associated with Helicobacter pylori, but the bacterium often is undetectable in these lesions. To unravel this apparent paradox, IM, H. pylori presence, and the expression of H. pylori virulence genes were quantified concurrently using histologic testing, in situ hybridization, and immunohistochemistry. H. pylori was detected inside metaplastic, dysplastic, and neoplastic epithelial cells, and cagA and babA2 expression was colocalized. Importantly, expression of cagA was significantly higher in patients with IM and adenocarcinoma than in control subjects. The preneoplastic "acidic" MUC2 mucin was detected only in the presence of H. pylori, and MUC2 expression was higher in patients with IM, dysplasia, and cancer. These novel findings are compatible with the hypothesis that all stages of gastric carcinogenesis are fostered by persistent intracellular expression of H. pylori virulence genes, especially cagA inside MUC2-producing precancerous gastric cells and pleomorphic cancer cells.
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- Asker, Noomi, 1968, et al.
(författare)
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The human MUC2 mucin apoprotein appears to dimerize before O-glycosylation and shares epitopes with the 'insoluble' mucin of rat small intestine.
- 1995
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Ingår i: The Biochemical journal. - 0264-6021. ; 308:3, s. 873-80
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Tidskriftsartikel (refereegranskat)abstract
- Rabbit antiserum against a synthetic peptide corresponding to a tandemly repeated amino acid sequence in the human intestinal mucin apoprotein MUC2 was used in immunoprecipitation to study the biosynthesis of MUC2 in the colon-carcinoma cell line LS 174T. Under non-reducing conditions, two bands were precipitated, the smaller with an apparent size of about 700 kDa on SDS/PAGE. When analysed by two-dimensional electrophoresis after reduction, the larger band migrated to the same position as the smaller band and was interpreted as a putative disulphide-bond-stabilized dimer. Pulse-chase experiments showed only the monomer after 5 min and the appearance of the putative dimer after 30 min. The MUC2 apoprotein was also precipitated by antisera against the HF-deglycosylated peptides of the two highly glycosylated domains of the 'insoluble' mucin complex of rat small intestine [Carlstedt, Herrmann, Karlsson, Sheehan, Fransson and Hansson (1993) J. Biol. Chem. 268, [18771-18781]. Endoprotease Lys-C cleavage of the immunopurified apoprotein gave a large fragment of about 250 kDa that was detected by both the antiserum against the MUC2 tandem repeat and one of the glycopeptide antisera. This supports the view that the 'insoluble' mucin of rat small intestine is encoded by the Muc2 gene, as recently indicated by a partial cDNA sequence [Hansson, Baeckström, Carlstedt and Klinga-Levan (1994) Biochem. Biophys. Res. Commun. 198, 181-190] and that parts of the apoprotein are conserved between the species. A lectin from the snail Helix pomatia that detects terminal alpha-GalNAc residues did not bind to the monomer or putative dimer, suggesting that O-glycosylation starts after dimerization. The results indicate that the biosynthetic pathway of the MUC2 mucin may be similar to that of the von Willebrand factor with which MUC2 shares sequence similarities at its C- and N-termini.
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- Bornehag, Carl-Gustaf, 1957-, et al.
(författare)
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Prenatal Phthalate Exposures and Anogenital Distance in Swedish Boys
- 2015
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 123:1, s. 101-107
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Phthalates are used as plasticizers in soft polyvinyl chloride (PVC) and in a large number of consumer products. Because of reported health risks, diisononyl phthalate (DiNP) has been introduced as a replacement for di(2-ethylhexyl) phthalate (DEHP) in soft PVC. This raises concerns because animal data suggest that DiNP may have antiandrogenic properties similar to those of DEHP. The anogenital distance (AGD)-the distance from the anus to the genitals-has been used to assess reproductive toxicity. OBJECTIVE: The objective of this study was to examine the associations between prenatal phthalate exposure and AGD in Swedish infants. METHODS: AGD was measured in 196 boys at 21 months of age, and first-trimester urine was analyzed for 10 phthalate metabolites of DEP (diethyl phthalate), DBP (dibutyl phthalate), DEHP, BBzP (benzylbutyl phthalate), as well as DiNP and creatinine. Data on covariates were collected by questionnaires. RESULTS: The most significant associations were found between the shorter of two AGD measures (anoscrotal distance; AGDas) and DiNP metabolites and strongest for oh-MMeOP [mono(4-methyl-7-hydroxyloctyl) phthalate] and oxo-MMeOP [mono-(2-ethyl-5-oxohexyl) phthalate]. However, the AGDas reduction was small (4%) in relation to more than an interquartile range increase in DiNP exposure. CONCLUSIONS: These findings call into question the safety of substituting DiNP for DEHP in soft PVC, particularly because a shorter male AGD has been shown to relate to male genital birth defects in children and impaired reproductive function in adult males and the fact that human levels of DiNP are increasing globally.
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- Bornehag, Carl-Gustaf, et al.
(författare)
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Response to Risotto et al.
- 2013
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Ingår i: Indoor Air. ; 23, s. 87-88
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Tidskriftsartikel (refereegranskat)
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