925 resultados para association, development, activity
Resumo:
Tabanid females are better known as hematophagous on man and other mammals, and linked to mechanical transmission of parasites. The association between tabanids and reptiles is poorly known, but has been gaining more corroboration through experiments and occasional observation in the tropics. The present study was conducted at a military base (CIGS/BI-2), situated 54 km from Manaus, Amazonas, in a small stream in a clearing (02°45'33"S; 59°51'03"W). Observations were made monthly, from April 1997 to March 1998, during two consecutive days. At the same time, other vertebrate animals were offered, including humans. However in this paper only data obtained on a common caiman, Caiman crocodilus (Linn.), and an anaconda, Eunectes murinus (Linn.), in diurnal observations from 05:30 a.m. to 18:30 p.m., will be discussed. A total of 254 tabanid specimens were collected, 40 from the anaconda and 214 from the caiman. Four tabanid species were recorded on these two reptiles: Stenotabanus cretatus Fairchild, S. bequaerti Rafael et al., Phaeotabanus nigriflavus (Kröber) and Tabanus occidentalis Linn. Diurnal activities showed species-specific patterns. The first three species occurred only in the dry season. T. occidentalis occurred during the whole observation period, and with increased frequency at the end of the dry season. We observed preferences for body area and related behavior of the host. Observations on the attack of tabanids on one dead caiman are also presented.
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The mechanical behaviour of ectodermal cells in the area opaca and the supracellular organization of fibronectin in the adjacent extracellular matrix were studied in whole chick blastoderms developing in vitro. The pattern of spontaneous mechanical activity and its modification by immunoglobulins against fibronectin were determined using a real-time image-analysis system. The pattern of fibronectin was studied using immunocytochemical techniques. It was found that the ectodermal cells in the area opaca actively develop a radially oriented contraction, which leads to a distension of the area pellucida from which the embryo develops. Abnormally increased tension resulted in perturbations of gastrulation and neurulation. An optimized mechanical equilibrium within the blastoderm seems to be necessary for normal development. Anti-fibronectin antibodies applied to the basal side of the blastoderm led rapidly and reversibly to an increase of tension in the contracted cells. This observation indicates that modifications of the extracellular matrix can be transmitted to cytoskeletal elements within adjacent cells. The extracellular matrix of the area opaca contains fibronectin arranged in radially oriented fibrils. This orientation corresponds to the direction of migration of the mesodermal cells. Interestingly, the radial pattern of fibronectin is found in the regions where the ectodermal cells are contracted and develop radially oriented forces. This observation suggests that the supracellular assembly of the extracellular materials could be influenced by the mechanical activity of adjacent cells. Possible modulations of the supracellular organization of extracellular matrix by other factors, e.g. diffusible metabolites, is also discussed. The presence of characteristically organized extracellular matrix components, of spatially differentiated cell activities and of reciprocal interactions between them makes the young chick blastoderm an excellent system for physiological studies of the coordinated cellular activities that lead to changes in form, complexity and function.
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OBJECTIVEIncrease in adipose cAMP response binding protein (CREB) activity promotes adipocyte dysfunction and systemic insulin resistance in obese mice. This is achieved by increasing the expression of activating transcription factor 3 (ATF3). In this study we investigated whether impaired expression of the inducible cAMP early repressor (ICER), a transcriptional antagonist of CREB, is responsible for the increased CREB activity in adipocytes of obese mice and humans.RESEARCH DESIGN AND METHODSTotal RNA and nuclear proteins were prepared from visceral adipose tissue (VAT) of human nonobese or obese subjects, and white adipose tissue (WAT) of C57Bl6-Rj mice that were fed with normal or high-fat diet for 16 weeks. The expression of genes was monitored by real-time PCR, Western blotting, and electromobility shift assays. RNA interference was used to silence the expression of Icer.RESULTSThe expression of Icer/ICER was reduced in VAT and WAT of obese humans and mice, respectively. Diminution of Icer/ICER was restricted to adipocytes and was accompanied by a rise of Atf3/ATF3 and diminution of Adipoq/ADIPOQ and Glut4/GLUT4. Silencing the expression of Icer in 3T3-L1 adipocytes mimicked the results observed in human and mice cells and hampered glucose uptake, thus confirming the requirement of Icer for appropriate adipocyte function.CONCLUSIONSImpaired expression of ICER contributes to elevation in CREB target genes and, therefore, to the development of insulin resistance in obesity.
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In the whole animal, metabolic regulations are set by reciprocal interactions between various organs, via the blood circulation. At present, analyses of such interactions require numerous and uneasily controlled in vivo experiments. In a search for an alternative to in vivo experiments, our work aims at developing a coculture system in which different cell types are isolated in polymer capsules and grown in a common environment. The signals exchanged between cells from various origins are, thus, reproducing the in vivo intertissular communications. With this perspective, we evaluated a new encapsulation system as an artificial housing for liver cells on the one hand and adipocytes on the other hand. Murine hepatocytes were encapsulated with specially designed multicomponent capsules formed by polyelectrolyte complexation between sodium alginate, cellulose sulphate and poly(methylene-coguanidine) hydrochloride, of which the permeability has been characterized. We demonstrated the absence of cytotoxicity and the excellent biocompatibility of these capsules towards primary culture of murine hepatocytes. Encapsulated hepatocytes retain their specific functions--transaminase activity, urea synthesis, and protein secretion--during the first four days of culture in minimum medium. Mature adipocytes, isolated from mouse epidydimal fat, were embedded in alginate beads. Measurement of protein secretion shows an identical profile between free and embedded adipocytes. We finally assessed the properties of encapsulated hepatocytes, cryopreserved over a periods of up to four months. The perspective of using encapsulated cells in coculture are discussed, since this system may represent a promising tool for fundamental research, such as analyses of drug metabolism, intercellular regulations, and metabolic pathways, as well as for the establishment of a tissue bank for storage and supply of murine hepatocytes.
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The development of targeted treatment strategies adapted to individual patients requires identification of the different tumor classes according to their biology and prognosis. We focus here on the molecular aspects underlying these differences, in terms of sets of genes that control pathogenesis of the different subtypes of astrocytic glioma. By performing cDNA-array analysis of 53 patient biopsies, comprising low-grade astrocytoma, secondary glioblastoma (respective recurrent high-grade tumors), and newly diagnosed primary glioblastoma, we demonstrate that human gliomas can be differentiated according to their gene expression. We found that low-grade astrocytoma have the most specific and similar expression profiles, whereas primary glioblastoma exhibit much larger variation between tumors. Secondary glioblastoma display features of both other groups. We identified several sets of genes with relatively highly correlated expression within groups that: (a). can be associated with specific biological functions; and (b). effectively differentiate tumor class. One prominent gene cluster discriminating primary versus nonprimary glioblastoma comprises mostly genes involved in angiogenesis, including VEGF fms-related tyrosine kinase 1 but also IGFBP2, that has not yet been directly linked to angiogenesis. In situ hybridization demonstrating coexpression of IGFBP2 and VEGF in pseudopalisading cells surrounding tumor necrosis provided further evidence for a possible involvement of IGFBP2 in angiogenesis. The separating groups of genes were found by the unsupervised coupled two-way clustering method, and their classification power was validated by a supervised construction of a nearly perfect glioma classifier.
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Synthesis of polyhydroxyalkanoates (PHAs) from intermediates of fatty acid beta-oxidation was used as a tool to study fatty acid degradation in developing seeds of Arabidopsis. Transgenic plants expressing a peroxisomal PHA synthase under the control of a napin promoter accumulated PHA in developing seeds to a final level of 0. 06 mg g(-1) dry weight. In plants co-expressing a plastidial acyl-acyl carrier protein thioesterase from Cuphea lanceolata and a peroxisomal PHA synthase, approximately 18-fold more PHA accumulated in developing seeds. The proportion of 3-hydroxydecanoic acid monomer in the PHA was strongly increased, indicating a large flow of capric acid toward beta-oxidation. Furthermore, expression of the peroxisomal PHA synthase in an Arabidopsis mutant deficient in the enzyme diacylglycerol acyltransferase resulted in a 10-fold increase in PHA accumulation in developing seeds. These data indicate that plants can respond to the inadequate incorporation of fatty acids into triacylglycerides by recycling the fatty acids via beta-oxidation and that a considerable flow toward beta-oxidation can occur even in a plant tissue primarily devoted to the accumulation of storage lipids.
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Background: Inadequate intraoperative cerebral perfusion and increased serum anticholinergic activity (SAA) have been suggested as possible causes of postoperative cognitive dysfunction (POCD). Methods: 53 patients aged >65 yrs undergoing elective major surgical procedures under standardized general anaesthesia. Cerebral perfusion was monitored with transcranial Doppler and near-infrared spectroscopy. Mx, an index of cerebral autoregulation was calculated based on the correlation of spontaneous changes inmean arterial blood pressure (MAP) and cerebral blood flow velocity. Cognitive function was measured preoperatively and 7 days postoperatively using the CERAD-Neuropsychological Battery. A postoperative decline >1 z-score in at least 2 cognitive variables was defined as POCD. SAA was measured preoperatively and 7 days postoperatively (data available for 38 patients). CRP was measured at the same time points and 2 days postoperatively. Results: Age was 75_7 yrs (mean_SD). 23 patients (43%) developed POCD. There were no statistical significant differences between patients with POCD and without POCD in age (77_7 vs 73_6 yrs), MAP (74_12 vs 78_11 mmHg), cerebral tissue oxygenation indices (67_6 vs 69_4 %) SAA preoperatively (1.74_1.52 vs 1.74_1.21) and 7 days postoperatively (1.90_1.63 vs 1.84_1.39) and CRP preoperatively (32_72 vs 7_9), 2 days postoperatively (176_129 vs 111_69) and 7days postoperatively (53_43 vs 48_25). Patients with POCD had less efficient autoregulation than patients without POCD (Mx 0.55_0.15 vs 0.45_0.20, p = 0.046). However, the percentage of patients with clearly impaired autoregulation (ie, Mx>0.5) was statistically not different between groups (with POCD: 65%; without POCD: 38%; p = 0.06) but there seems to be a trend. Conclusions: Our data on the association between cerebral perfusion and POCD in elderly patients are inconclusive and more patients need to be investigated. In this small group of patients SAA seems not to be associated with POCD.
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We aimed to compare physical activity level and cardiorespiratory fitness in children with different chronic diseases, such as type 1 diabetes mellitus (T1DM), obesity (OB) and juvenile idiopathic arthritis (JIA), with healthy controls (HC). We performed a cross-sectional study including 209 children: OB: n = 45, T1DM: n = 48, JIA: n = 31, and HC: n = 85. Physical activity level was assessed by accelerometer and cardiorespiratory fitness by a treadmill test. ANOVA, linear regressions and Pearson correlations were used. Children with chronic diseases had reduced total daily physical activity counts (T1DM 497 +/- 54 cpm, p = 0.003; JIA 518 +/- 28, p < 0.001, OB 590 +/- 25, p = 0.003) and cardiorespiratory fitness (JIA 39.3 +/- 1.7, p = 0.001, OB 41.7 +/- 1.2, p = 0.020) compared to HC (668 +/- 35 cpm; 45.3 +/- 0.9 ml kg(-1) min(-1), respectively). Only 60.4% of HC, 51.6% of OB, 38.1% of JIA and 38.5% of T1DM children met the recommended daily 60 min of moderate-to-vigorous physical activity. Low cardiorespiratory fitness was associated with female gender and low daily PA. Children with chronic diseases had reduced physical activity and cardiorespiratory fitness. As the benefits of PA on health have been well demonstrated during growth, it should be encouraged in those children to prevent a reduction of cardiorespiratory fitness and the development of comorbidities.
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Laurencetown, Lenaderg & Tullylish Community Association (LLT) manage a community centre which serves the surrounding rural areas. Programmes include: parent & toddler, youth group, older peopleï¿_s group (offering 1-1 support) and supports other outlying rural groups. LLT has completed 3 Level 2 projects in the past.The first 3 projects have helped develop better understanding and promoted better access to pharmacy services etc (3 miles away), have raised the profile of LLT and put health on the agenda and has worked well with a range of specific groups including men, older people, pre schoolers etc and is currently seeking to target teenagers and parents. A good working relationship has developed between the pharmacist and LLT. They want to continue a similar approach developed through their Level 2 applications but with an increased focus on pre-school children and young people (teenagers) with their parents. Year 1 includes a health fair, 6 talks to local groups, 10 consultations for older people, 4 sessions for mothers, 4 sessions for fathers and 3 sessions with young people. Most of these, apart from the Health Fair, will be repeated in Year 2 & 3.
Resumo:
The project will develop a relationship with the pharmacist in Bessbrook and Kilkeel. 3 sessions will be held in each area allowing time for 1-1 support for clients and carers.
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BACKGROUND: Vitamin D insufficiency has been associated with the occurrence of various types of cancer, but causal relationships remain elusive. We therefore aimed to determine the relationship between genetic determinants of vitamin D serum levels and the risk of developing hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). METHODOLOGYPRINCIPAL FINDINGS: Associations between CYP2R1, GC, and DHCR7 genotypes that are determinants of reduced 25-hydroxyvitamin D (25[OH]D3) serum levels and the risk of HCV-related HCC development were investigated for 1279 chronic hepatitis C patients with HCC and 4325 without HCC, respectively. The well-known associations between CYP2R1 (rs1993116, rs10741657), GC (rs2282679), and DHCR7 (rs7944926, rs12785878) genotypes and 25(OH)D3 serum levels were also apparent in patients with chronic hepatitis C. The same genotypes of these single nucleotide polymorphisms (SNPs) that are associated with reduced 25(OH)D3 serum levels were found to be associated with HCV-related HCC (P = 0.07 [OR = 1.13, 95% CI = 0.99-1.28] for CYP2R1, P = 0.007 [OR = 1.56, 95% CI = 1.12-2.15] for GC, P = 0.003 [OR = 1.42, 95% CI = 1.13-1.78] for DHCR7; ORs for risk genotypes). In contrast, no association between these genetic variations and liver fibrosis progression rate (P>0.2 for each SNP) or outcome of standard therapy with pegylated interferon-α and ribavirin (P>0.2 for each SNP) was observed, suggesting a specific influence of the genetic determinants of 25(OH)D3 serum levels on hepatocarcinogenesis. CONCLUSIONSSIGNIFICANCE: Our data suggest a relatively weak but functionally relevant role for vitamin D in the prevention of HCV-related hepatocarcinogenesis.
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This briefing has been written in conjunction with the Local Government Association (LGA). It is aimed at those who work in or represent local authorities. It addresses the issue of taking action to create environments where people are more likely to walk or cycle for short journeys. It summarises the importance of action on obesity and a specific focus on active travel, and outlines the regulatory and policy approaches that can be taken.
Resumo:
The aims of the REACH programme were to: - Provide a quality whole-family healthy lifestyle programme that is accessible and equitable to support children aged 4-7 and 8-11years who are above the healthy weight range in maintaining or achieving a healthy weight; - Target areas of poor health and high prevalence of childhood obesity; Contribute towards the prevention and reduction of obesity prevalence in South Gloucestershire; - Be a resource for other health professionals and services in South Gloucestershire. As this was a pilot of a child weight management programme being developed from scratch the objectives of REACH were to: Provide a high quality service which meets the needs of the local health community; - Improve childrens diet and nutritional intake and promote a healthy weight; Encourage exercise and physical activity participation; - Develop a range of skills with participants in order to increase their confidence and self esteem; - Be participant centred but also use a whole family approach to deliver healthy lifestyle messages; - Develop appropriate referral protocols, resources and course plans; - Advertise and promote the programme locally liaising with communications and the Public Health Team in NHS South Gloucestershire, GPs and staff working in the community such as School Health Nurses (SHNs); - Successfully recruit families on to the programme; Enable eligible new participants referred to the service to take part; - Encourage participants to complete the programme; - Deliver a service that helps to address health inequalities; - Monitor participants weight and lifestyle changes as part of a follow up programme; - Provide continuous professional development of service staff; - Ensure individuals and families are signposted and supported to access other services such as after school clubs, local sports clubs and leisure centres; - Provide equitable access to the service and ensure equitable outcomes are achieved by the service; Ensure continuous quality improvement;
Functional Characterization of a n NTPase Activity of the Hepatitis C Virus Nonstructural Protein 4B
Resumo:
Background: Nonstructural p rotein 4 B (NS4B) i s the m asterorganizer of hepatitis C virus (HCV) replication complexformation. It is a multispanning membrane protein that has beenreported to p ossess NTPase activity. This enzymatic functionhas been poorly studied so far and its role in the HCV life cycleis u nknown. T he present w ork-in-progress a ims at validatingand functionally c haracterizing this a ctivity a nd its r ole in t heviral life cycle.Methods: B ioinformatic analyses were performed to i dentifykey residues for site-directed mutagenesis, both in t he contextof s ubgenomic r eplicons a s well as recombinant v iruses.Mutants were investigated with respect to R NA replication andinfectious particle p roduction. In p arallel, expression andpurification of recombinant wild-type and mutant NS4B proteinsare being pursued to characterize enzymatic activity in vitro.Results: B ioinformatic a nalyses revealed t hat p redictedNTPase features are conserved only in H CV NS4B b ut n ot i nNS4B from other Flaviviridae f amily m embers. A laninesubstitutions were designed to target predicted key Walker A, Band C motifs. These substitutions affected RNA replication andinfectious virus production to v arying degrees. Optimization ofrecombinant protein production is i n progress both in b acterialas well as mammalian expression systems.Conclusions: These studies should yield new insights into thefunctions of this hitherto poorly characterized viral nonstructuralprotein and may reveal novel targets for antiviral intervention inthe future.
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This study aimed to analyze the final fermentation culture of Bacillus sphaericus 2362, standardize it and develop an active tablet formulation for use in urban mosquito breeding sites. It was performed in three phases: analysis and standardization of a B. sphaericus fermented culture; physical, chemical, and biological analysis of the active powder (solubility, residual humidity, particle size, resting angle, flowing off time, compacted density, and biological activity against Culex quinquefasciatus larvae); and the development of fast-disintegrating tablets. Five formulations with differing compositions were developed and a UV protector was added to the selected formulation. The formulation products with or without UV protector, as well as the active powder caused 100% larval mortality from 1 day to 2 months after a single treatment under simulated field conditions. These results show that the UV protector does not affect the initial larvicide activity of B. sphaericus, nor its persistence over a period of two months.