1,807 research outputs found
Antimicrobial properties of mucus from the brown garden snail Helix aspersa
Research into naturally occurring antimicrobial substances has yielded effective treatments. One area of interest is peptides and proteins produced by invertebrates as part of their defence system, including the contents of mollusc mucus. Mucus produced by the African giant land snail, Achatina fulica has been reported to contain two proteins with broad-spectrum antibacterial activity. Mucus from the brown garden snail, Helix aspersa, appears to have skin regeneration properties. This study sought to investigate the antimicrobial properties of H. aspersa mucus. Mucus was collected from H. aspersa snails, diluted in phosphatebuffered saline (PBS), with the supernatant tested against a wide range of organisms in a disc-diffusion antimicrobial assay. This was followed with comparative experiments involving A. fulica, including bacteriophage assays. Mucus from both species of snail was passed through a series of protein size separation columns in order to determine the approximate size of the antimicrobial substance. Electrophoresis was also carried out on the H. aspersa mucus. Results indicated that H. aspersa mucus had a strong antibacterial effect against several strains of Pseudomonas aeruginosa and a weak effect against Staphylococcus aureus. Mucus from A. fulica also inhibited the growth of S. aureus, but the broad spectrum of activity reported by other workers was not observed. Antimicrobial activity was not caused by bacteriophage. Size separation experiments indicated that the antimicrobial substance(s) in H. aspersa were between 30 and 100 kDa. Electrophoresis revealed two proteins in this region (30–40 kDa and 50–60 kDa). These do not correspond with antimicrobial proteins previously reported in A. fulica. This study found one or more novel antimicrobial agents in H. aspersa mucus, with a strong effect against P. aeruginosa
Heterologously-expressed and Liposome-reconstituted Human Transient Receptor Potential Melastatin 4 Channel (TRPM4) is a Functional Tetramer
Mutation, irregular expression and sustained activation of the Transient Receptor Potential Channel, type Melastatin 4 (TRPM4), have been linked to various cardiovascular diseases. However, much remains unknown about the structure of this important ion channel. Here, we have purified a heterologously expressed TRPM4-eGFP fusion protein and investigated the oligomeric state of TRPM4-eGFP in detergent micelles using crosslinking, native gel electrophoresis, multi-angle laser light scattering and electron microscopy. Our data indicate that TRPM4 is tetrameric, like other TRP channels studied to date. Furthermore, the functionality of liposome reconstituted TRPM4-eGFP was examined using electrophysiology. Single-channel recordings from TRPM4-eGFP proteoliposomes showed inhibition of the channel using Flufenamic acid, a well-established inhibitor of TRPM4, suggesting that the channels are functional upon reconstitution. Our characterisation of the oligomeric structure of TRPM4 and the ability to reconstitute functional channels in liposomes should facilitate future studies into the structure, function and pharmacology of this therapeutically relevant channel
Social deprivation and exposure to health promotion. A study of the distribution of health promotion resources to schools in England
This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright @ 2010 Chivu and ReidpathBACKGROUND: Area deprivation is a known determinant of health. It is also known that area deprivation is associated with lower impact health promotion. It is less well known, however, whether deprived areas are less responsive to health promotion, or whether they are less exposed. Using data from a national, school-based campaign to promote vaccination against the human papilloma virus (HPV), the relationship between area deprivation and exposure was examined.
METHODS: Taking advantage of a health promotion campaign to provide information to schools about HPV vaccination, a cross sectional study was conducted to examine the relationship between area level, social deprivation, and take-up of (i.e., exposure to) available health promotion material. The sample was 4,750 schools across England, including government maintained and independent schools. The relationship between area deprivation and exposure was examined using bi- and multivariate logistic regression.
RESULTS: It was found that schools in the least deprived quintile had 1.32 times the odds of requesting health promotion materials than schools in the most deprived areas (p = .01). This effect was independent of the school size, the type of school, and the geographic region.
Conclusion
The relationship between area deprivation and the impact of health promotion may be due, at least in part, to differential levels of exposure. The study was limited in scope, pointing to the need for more research, but also points to potentially important policy implications
Identification and validation of oncologic miRNA biomarkers for Luminal A-like breast cancer
Introduction: Breast cancer is a common disease with distinct tumor subtypes phenotypically characterized by ER and HER2/neu receptor status. MiRNAs play regulatory roles in tumor initiation and progression, and altered miRNA expression has been demonstrated in a variety of cancer states presenting the potential for exploitation as cancer biomarkers. Blood provides an excellent medium for biomarker discovery. This study investigated systemic miRNAs differentially expressed in Luminal A-like (ER+PR+HER2/neu-) breast cancer and their effectiveness as oncologic biomarkers in the clinical setting. Methods: Blood samples were prospectively collected from patients with Luminal A-like breast cancer (n=54) and controls (n=56). RNA was extracted, reverse transcribed and subjected to microarray analysis (n=10 Luminal A-like; n=10 Control). Differentially expressed miRNAs were identified by artificial neural network (ANN) data-mining algorithms. Expression of specific miRNAs was validated by RQ-PCR (n=44 Luminal A; n=46 Control) and potential relationships between circulating miRNA levels and clinicopathological features of breast cancer were investigated. Results: Microarray analysis identified 76 differentially expressed miRNAs. ANN revealed 10 miRNAs for further analysis ( miR-19b, miR-29a, miR-93, miR-181a, miR-182, miR-223, miR-301a, miR-423-5p, miR-486-5 and miR-652 ). The biomarker potential of 4 miRNAs ( miR-29a, miR-181a , miR-223 and miR-652 ) was confirmed by RQ-PCR, with significantly reduced expression in blood of women with Luminal A-like breast tumors compared to healthy controls (p=0.001, 0.004, 0.009 and 0.004 respectively). Binary logistic regression confirmed that combination of 3 of these miRNAs ( miR-29a, miR-181a and miR-652 ) could reliably differentiate between cancers and controls with an AUC of 0.80. Conclusion: This study provides insight into the underlying molecular portrait of Luminal A-like breast cancer subtype. From an initial 76 miRNAs, 4 were validated with altered expression in the blood of women with Luminal A-like breast cancer. The expression profiles of these 3 miRNAs, in combination with mammography, has potential to facilitate accurate subtype- specific breast tumor detection
Is there a role for publication consultants and how should their contribution be recognized?
When a scientific paper, dissertation or thesis is published the author(s) have a duty to report who has contributed to the work. This recognition can take several forms such as authorship, relevant acknowledgments and by citing previous work. There is a growing industry where publication consultants will work with authors, research groups or even institutions to help get their work published, or help submit their dissertation/thesis. This help can range from proof reading, data collection, analysis (including statistics), helping with the literature review and identifying suitable journals/conferences. In this opinion article we question whether these external services are required, given that institutions should provide this support and that experienced researchers should be qualified to carry out these activities. If these services are used, we argue that their use should at least be made transparent either by the consultant being an author on the paper, or by being acknowledged on the paper, dissertation or thesis. We also argue that publication consultants should provide an annual return that details the papers, dissertations and thesis that they have consulted on
Which circulating antioxidant vitamins are confounded by socioeconomic deprivation? The MIDSPAN family study
<p><b>Background:</b> Antioxidant vitamins are often described as having “independent” associations with risk of cancer, cardiovascular disease (CVD) and mortality. We aimed to compare to what extent a range of antioxidant vitamins and carotenoids are associated with adulthood and childhood markers of socioeconomic deprivation and to adverse lifestyle factors.</p>
<p><b>Methods and Findings:</b> Socioeconomic and lifestyle measures were available in 1040 men and 1298 women from the MIDSPAN Family Study (30–59 years at baseline) together with circulating levels of vitamins A, C, E, and carotenoids (α-carotene, β-carotene, lutein and lycopene). Markers of socioeconomic deprivation in adulthood were consistently as strongly associated with lower vitamin C and carotenoid levels as markers of adverse lifestyle; the inverse association with overcrowding was particularly consistent (vitamin C and carotenoids range from 19.1% [95% CI 30.3–6.0] to 38.8% [49.9–25.3] lower among those in overcrowded residencies). These associations were consistent after adjusting for month, classical CVD risk factors, body mass index, physical activity, vitamin supplements, dietary fat and fibre intake. Similar, but weaker, associations were seen for childhood markers of deprivation. The association of vitamin A or E were strikingly different; several adult adverse lifestyle factors associated with higher levels of vitamin A and E, including high alcohol intake for vitamin A (9.5% [5.7–13.5]) and waist hip ratio for vitamin E (9.5% [4.8–14.4]), with the latter associations partially explained by classical risk factors, particularly cholesterol levels.</p>
<p><b>Conclusions:</b> Plasma vitamin C and carotenoids have strong inverse associations with adulthood markers of social deprivation, whereas vitamin A and E appear positively related to specific adverse lifestyle factors. These findings should help researchers better contextualize blood antioxidant vitamin levels by illustrating the potential limitations associated with making causal inferences without consideration of social deprivation.</p>
Associations between Serum Vitamin D and Genetic Variants in Vitamin D Pathways and Age-Related Macular Degeneration in the European Eye Study.
PURPOSE: To study associations between early and late age-related macular degeneration (AMD) and neovascular AMD (nvAMD) with serum 25-hydroxy vitamin D (25(OH)D) and genetic variants in vitamin D pathway genes. DESIGN: Population-based, cross-sectional study in a random sample aged 65 years or older from 7 European countries. PARTICIPANTS: Of 4753 participants, 4496 (2028 men and 2468 women), with a mean age of 73 years, provided a blood sample; 2137 had no signs of AMD, 2209 had early AMD, and 150 had late AMD, of whom 104 had nvAMD. METHODS: Participants were interviewed to determine smoking and alcohol use, sunlight exposure, and diet; underwent fundus photography. Fundus images were graded using the International Classification System for Age-Related Maculopathy. The 25(OH)D was measured by liquid chromatography-tandem mass spectrometry and categorized as deficient (<30 nmol/l), insufficient (30-50 nmol/l), or adequate (≥50 nmol/l). Genotyping was performed on a subsample of 1284 AMD cases and controls for 93 single nucleotide polymorphisms (SNPs) from 7 genes. Associations were investigated by linear or logistic regression adjusted for potential confounders. MAIN OUTCOME MEASURES: Adjusted odds ratio (OR) for 3 outcomes (early AMD, late AMD, nvAMD). RESULTS: No linear association was found with 25(OH)D and early or late AMD or nvAMD. There was no association between insufficient or deficient status with early or late AMD. Deficient status was associated with nvAMD (adjusted OR, 1.27; 95% confidence interval, 1.1-1.45; P < 0.0001). Significant (P < 0.05) associations with 25(OH)D were found for SNPs in genes GC, VDR, CYP2R1, and CYP27B1. Two SNPs (VDR) were associated with early AMD, 4 SNPs (RXRA) and 1 SNP (VDR) were associated with nvAMD, and 1 SNP (RXRA), 2 SNPs (VDR), and 1 SNP (CYP2R1) were associated with late AMD. After Bonferroni correction, no SNPs were associated with early AMD, late AMD, or nvAMD. CONCLUSIONS: Deficiency in 25(OH)D was associated with nvAMD, but the adjusted OR was small, and we cannot exclude residual confounding. The hypothesis of a causal association of vitamin D with AMD is not supported by clear evidence for an association of vitamin D SNPs with early AMD, late AMD, or nvAMD
Bio-psychosocial determinants of cardiovascular disease in a rural population on Crete, Greece: formulating a hypothesis and designing the SPILI-III study
Background: In 1988, the SPILI project was established in order to evaluate the cardiovascular disease (CVD) risk
profile of the inhabitants of Spili, in rural Crete, Greece. The first reports from this project revealed that against the unfavourable risk factors’ profile observed, only a few men with a previous myocardial infarction were encountered. A follow-up study (SPILI II) was performed twelve years after the initial examination, and the unfavourable cardiovascular risk profile was re-confirmed.
Presentation of the Hypothesis: This paper presents a hypothesis formulated on the basis of previous research to
investigate if dynamic psycho-social determinants, including social coherence of the local community, religiosity and spirituality, are protective against the development of coronary heart disease in a well-defined population. Testing the Hypothesis: A follow-up examination of this Cretan cohort is currently being performed to assess the link between psychosocial factors and CVD. Psychosocial factors including sense of control, religiosity and spirituality are assessed in together with conventional CVD risk factors. Smoking and alcohol consumption, as well as dietary habits and activity levels are recorded. Oxidative stress and inflammatory markers, as well as ultrasound measurement of carotid intima media thickness, a preclinical marker of atherosclerosis, will also be measured. Implications of the hypothesis tested: The issue of the cardio-protective effect of psycho-social factors would be revisited based on the results of this Cretan cohort; nevertheless, further research is needed across different subpopulations in order to establish a definite relationship. A comprehensive approach based on the aspects of biosocial life may result in more accurate CVD risk management
Association Between Myopia, Ultraviolet B Radiation Exposure, Serum Vitamin D Concentrations, and Genetic Polymorphisms in Vitamin D Metabolic Pathways in a Multicountry European Study.
IMPORTANCE: Myopia is becoming increasingly common globally and is associated with potentially sight-threatening complications. Spending time outdoors is protective, but the mechanism underlying this association is poorly understood. OBJECTIVE: To examine the association of myopia with ultraviolet B radiation (UVB; directly associated with time outdoors and sunlight exposure), serum vitamin D concentrations, and vitamin D pathway genetic variants, adjusting for years in education. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional, population-based random sample of participants 65 years and older was chosen from 6 study centers from the European Eye Study between November 6, 2000, to November 15, 2002. Of 4187 participants, 4166 attended an eye examination including refraction, gave a blood sample, and were interviewed by trained fieldworkers using a structured questionnaire. Myopia was defined as a mean spherical equivalent of -0.75 diopters or less. Exclusion criteria included aphakia, pseudophakia, late age-related macular degeneration, and vision impairment due to cataract, resulting in 371 participants with myopia and 2797 without. EXPOSURES: Exposure to UVB estimated by combining meteorological and questionnaire data at different ages, single-nucleotide polymorphisms in vitamin D metabolic pathway genes, serum vitamin D3 concentrations, and years of education. MAIN OUTCOMES AND MEASURES: Odds ratios (ORs) of UVB, serum vitamin D3 concentrations, vitamin D single-nucleotide polymorphisms, and myopia estimated from logistic regression. RESULT: Of the included 3168 participants, the mean (SD) age was 72.4 (5) years, and 1456 (46.0%) were male. An SD increase in UVB exposure at age 14 to 19 years (OR, 0.81; 95% CI, 0.71-0.92) and 20 to 39 years (OR, 0.7; 95% CI, 0.62-0.93) was associated with a reduced adjusted OR of myopia; those in the highest tertile of years of education had twice the OR of myopia (OR, 2.08; 95% CI, 1.41-3.06). No independent associations between myopia and serum vitamin D3 concentrations nor variants in genes associated with vitamin D metabolism were found. An unexpected finding was that the highest quintile of plasma lutein concentrations was associated with a reduced OR of myopia (OR, 0.57; 95% CI, 0.46-0.72). CONCLUSIONS AND RELEVANCE: Increased UVB exposure was associated with reduced myopia, particularly in adolescence and young adulthood. The association was not altered by adjusting for education. We found no convincing evidence for a direct role of vitamin D in myopia risk. The relationship between high plasma lutein concentrations and a lower risk of myopia requires replication
New insights into the phylogeny of Entamoeba species provided by analysis of four new small-subunit rRNA genes.
Sequences of small-subunit rRNA genes have been obtained for four new isolates of Entamoeba. Phylogenetic analyses give new insights into the evolution of these organisms. A novel Entamoeba from pigs in Vietnam that produces uninucleate cysts proved to be unrelated to other uninucleated cyst-producing species. Revival of the name Entamoeba suis for this organism is proposed. Instead of being related to Entamoeba polecki, it shares a recent common ancestor with the non-encysting Entamoeba gingivalis in a lineage that is basal to the tetranucleate cyst-producing clade. This suggests that species producing cysts with four nuclei are descended from an ancestor that produced cysts with a single nucleus. An Entamoeba from a horse was isolated in culture. No cysts were observed in the original stool sample but the sequence is placed unequivocally within the clade of tetranucleate cyst-producing species with no other sequences being specifically related. Revival of the name Entamoeba equi for this organism is proposed. The Entamoeba ecuadoriensis sequence was found to be the most closely related to Entamoeba histolytica and Entamoeba dispar, as predicted, despite the organism having been an environmental isolate originally assigned to Entamoeba moshkovskii. Finally, a partial E. polecki gene sequence from a pig proved to be virtually identical to that of Entamoeba struthionis from an ostrich, suggesting that the latter name is a synonym
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