132 research outputs found
Identification of an Antimicrobial Peptide from the Venom of the Trinidad Thick-Tailed Scorpion Tityus trinitatis with Potent Activity against ESKAPE Pathogens and Clostridioides difficile
Envenomation by the Trinidad thick-tailed scorpion Tityus trinitatis may result in fatal myocarditis and there is a high incidence of acute pancreatitis among survivors. Peptidomic analysis (reversed-phase HPLC followed by MALDI-TOF mass spectrometry and automated Edman degradation) of T. trinitatis venom led to the isolation and characterization of three peptides with antimicrobial activity. Their primary structures were established asTtAP-1 (FLGSLFSIGSKLLPGVFKLFSRKKQ.NH2), TtAP-2 (IFGMIPGLIGGLISAFK.NH2) and TtAP-3 (FFSLIPSLIGGLVSAIK.NH2). In addition, potassium channel and sodium channel toxins, present in the venom in high abundance, were identified by CID-MS/MS sequence analysis. TtAP-1 was the most potent against a range of clinically relevant Gram-positive and Gram-negative aerobes and against the anaerobe Clostridioides difficile (MIC = 3.1–12.5 µg/mL). At a concentration of 1× MIC, TtAP-1 produced rapid cell death (Acinetobacter baumannii and Staphylococcus aureus). The therapeutic potential of TtAP-1 as an anti-infective agent is limited by its high hemolytic activity (LC50 = 18 µg/mL against mouse erythrocytes) but the peptide constitutes a template for the design of analogs that maintain the high bactericidal activity against ESKAPE pathogens but are less toxic to human cells. It is suggested that the antimicrobial peptides in the scorpion venom facilitate the action of the neurotoxins by increasing the membrane permeability of cells from either prey or predator
Saturated fat in the diet of Spanish children: relationship with anthropometric, alimentary, nutritional and lipid profiles
OBJECTIVE: To compare the anthropometric, alimentary, nutritional and lipid profiles and global diet quality of Spanish children according to saturated fat intake. DESIGN: This was a cross-sectional study. Food data were collected using a food-frequency questionnaire. SUBJECTS AND METHODS: The sample included 1112 children of both sexes, aged between 6 and 7 years, selected by means of random cluster sampling in schools. The plasma lipid profile included measurements of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, apolipoprotein A1 (apoA1) and apolipoprotein B (apoB). Global diet quality was evaluated by the Dietary Variety Index (DVI) and the Healthy Eating Index (HEI). RESULTS: Energy intake, DVI and HEI of children from the lower quartile of saturated fat intake (LL) were higher (P<001) than in the remaining children (UL). However, there were no significant differences in average height or weight between groups. The UL children had lower intakes of meat, fish, vegetables, fruits and olive oil and a higher intake of dairy products (P<0.001). The intakes of fibre, vitamins C, D, B6, E and folic acid were higher in the LL children, who had lower intakes of vitamin A and calcium. The ratios LDL-C/HDL-C and apoB/apoA1 were lower (P=0.04) in the LL children (1.87 and 0.52, respectively) than in the UL children (2.02 and 0.54, respectively). CONCLUSIONS: The growth rate of children does not seem to be affected by the level of saturated fat intake. Furthermore, at the levels of intake observed in this study, diets with less saturated fat are associated with better alimentary, nutritional and plasma lipid profiles.This study was partly funded by grants from the Fondo deInvestigacio ́n Sanitaria (FIS 020994, FIS02/3104) and theMinisterio Agricultura Pesca y Alimentacio ́n. We thankAlexander G Borun for manuscript revisionS
Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)
This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and
Technology (CICYT), the
Spanish National Parks agency, the European Commission, the
Spanish Ministry of Science, and the European
Social Fund
Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)
This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and
Technology (CICYT), the
Spanish National Parks agency, the European Commission, the
Spanish Ministry of Science, and the European
Social Fund
Assessment of osteoarthritis candidate genes in a meta-analysis of nine genome-wide association studies
OBJECTIVE:
To assess candidate genes for association with osteoarthritis (OA) and identify promising genetic factors and, secondarily, to assess the candidate gene approach in OA.
METHODS:
A total of 199 candidate genes for association with OA were identified using Human Genome Epidemiology (HuGE) Navigator. All of their single-nucleotide polymorphisms (SNPs) with an allele frequency of >5% were assessed by fixed-effects meta-analysis of 9 genome-wide association studies (GWAS) that included 5,636 patients with knee OA and 16,972 control subjects and 4,349 patients with hip OA and 17,836 control subjects of European ancestry. An additional 5,921 individuals were genotyped for significantly associated SNPs in the meta-analysis. After correction for the number of independent tests, P values less than 1.58 × 10(-5) were considered significant.
RESULTS:
SNPs at only 2 of the 199 candidate genes (COL11A1 and VEGF) were associated with OA in the meta-analysis. Two SNPs in COL11A1 showed association with hip OA in the combined analysis: rs4907986 (P = 1.29 × 10(-5) , odds ratio [OR] 1.12, 95% confidence interval [95% CI] 1.06-1.17) and rs1241164 (P = 1.47 × 10(-5) , OR 0.82, 95% CI 0.74-0.89). The sex-stratified analysis also showed association of COL11A1 SNP rs4908291 in women (P = 1.29 × 10(-5) , OR 0.87, 95% CI 0.82-0.92); this SNP showed linkage disequilibrium with rs4907986. A single SNP of VEGF, rs833058, showed association with hip OA in men (P = 1.35 × 10(-5) , OR 0.85, 95% CI 0.79-0.91). After additional samples were genotyped, association at one of the COL11A1 signals was reinforced, whereas association at VEGF was slightly weakened.
CONCLUSION:
Two candidate genes, COL11A1 and VEGF, were significantly associated with OA in this focused meta-analysis. The remaining candidate genes were not associated
Investigation on the competing effects of clay dispersion and matrix plasticisation for polypropylene/clay nanocomposites. Part II: Crystalline structure and thermo-mechanical behaviour
In view of the structure–property relationship, the mechanical property enhancement of polypropylene (PP)/clay nanocomposites can also be associated with the alterations of their crystalline structures and behaviour in addition to the general interpretation of intercalation/exfoliation level and uniform dispersion of more rigid clay platelets with higher aspect ratios in the PP matrix. Wide-angle X-ray diffraction (WAXD) was utilised to evaluate the effects of clay content, maleated PP (MAPP) content (MAPP as the compatibiliser) on PP crystalline structures of nanocomposites. Furthermore, the melting and crystallisation behaviour of PP/clay nanocomposites was also investigated by conducting differential scanning calorimetry (DSC). The thermo-mechanical properties were characterised via dynamic mechanical thermal analysis (DMTA). It is observed that enhancement of mechanical properties are mainly affected by the preferred orientation of PP crystals, the growth of α-PP phase and effective nucleating agent role of additional clay while the excessive amount of MAPP becomes detrimental to these crucial aspects, which is also evidently revealed in DMTA measurements
Occurrence of Corynebacterium striatum as an emerging antibiotic-resistant nosocomial pathogen in a Tunisian hospital
Corynebacterium striatum is a nosocomial opportunistic pathogen increasingly associated with a wide range of human infections and is often resistant to several antibiotics. We investigated the susceptibility of 63 C. striatum isolated at the Farhat-Hached hospital, Sousse (Tunisia), during the period 2011?2014, to a panel of 16 compounds belonging to the main clinically relevant classes of antimicrobial agents. All strains were susceptible to vancomycin, linezolid, and daptomycin. Amikacin and gentamicin also showed good activity (MICs90 = 1 and 2 mg/L, respectively). High rates of resistance to penicillin (82.5%), clindamycin (79.4%), cefotaxime (60.3%), erythromycin (47.6%), ciprofloxacin (36.5%), moxifloxacin (34.9%), and rifampicin (25.4%) were observed. Fifty-nine (93.7%) out of the 63 isolates showed resistance to at least one compound and 31 (49.2%) were multidrug-resistant. Twenty-nine resistance profiles were distinguished among the 59 resistant C. striatum. Most of the strains resistant to fluoroquinolones showed a double mutation leading to an amino acid change in positions 87 and 91 in the quinolone resistance-determining region of the gyrA gene. The 52 strains resistant to penicillin were positive for the gene bla, encoding a class A ?-lactamase. Twenty-two PFGE patterns were identified among the 63 C. striatum, indicating that some clones have spread within the hospital
Effects of mannoprotein E1 in liquid diet on inflammatory response and TLR5 expression in the gut of rats infected by Salmonella typhimurium
<p>Abstract</p> <p>Background</p> <p>Mannoproteins are yeast cell wall componend, and rich in mannose. The use of foods rich in mannose as carbohydrate, could have a bioprotective effect against entrobacteria intestinal infection. Nothing is known about mannoproteins' activity in inflammatory bowel processes induced by entrobacteria.</p> <p>This study investigates the effects of mannoprotein administration via a liquid diet on inflammatory response and TLR5 expression during intestinal tissue injury in a rat model of infection with <it>Salmonella typhimurium</it>.</p> <p>Methods</p> <p>Adult Wistar male rats were divided into three groups: control, and mannoprotein E<sub>1 </sub>at 10 or 15%. Animals were fed with a liquid diet supplemented or not with mannoprotein E<sub>1</sub>. Groups were infected by intragastrical administration of <it>S. typhimurium</it>. 24 h post-inoculation samples of spleen, ileum and liver were collected for microbiological studies. Gut samples were processed to determine levels of proinflammatory cytokines (mRNA) and TLR5 (mRNA and protein) by quantitative PCR and Western-blot, and the number of proliferative and apoptotic cells determined by immunohistochemistry.</p> <p>Results</p> <p>Ininfected levels of proinflammatory cytokines and TLR5 were higher in untreated controls than in the animals receiving mannoprotein. Proliferation was similar in both groups, whereas apoptosis was higher in controls. Curiosly, the mannoprotein effect was dose dependent.</p> <p>Conclusions</p> <p>Mannoprotein administration in a liquid diet seems to protect intestinal tissue against <it>S. typhimurium </it>infection. This protection seems to expressed as a lower pro-inflammatory response and TLR5 downregulation in gut epithelium, as well as by an inhibition of apoptosis. Nevertheless, the molecular mechanism by which mannoprotein is able to regulate these responses remain unclear. These results could open up new avenues in the use of mannoproteins as prebiotics in the therapeutic strategy for treatment of inflammatory gut processes induced by microbia.</p
- …