274 research outputs found

    The vasopressin Avprlb receptor: Molecular and pharmacological studies

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    The distribution, pharmacology and function of the arginine vasopressin (Avp) lb receptor subtype (Avprlb) has proved more challenging to investigate compared to other members of the Avp receptor family. Avp is increasingly recognised as an important modulator of the hypothalamic–pituitary–adrenal (HPA) axis, an action mediated by the Avprlb present on anterior pituitary corticotrophs. The Avprlb is also expressed in some peripheral tissues including pancreas and adrenal, and in the hippocampus (HIP), paraventricular nucleus and olfactory bulb of the rodent brain where its function is unknown. The central distribution of Avprlbs is far more restricted than that of the Avprla, the main Avp receptor subtype found in the brain. Whether Avprlb expression in rodent tissues is dependent on differences in the length of microsatellite dinucleotide repeats present in the 5′ promoter region of the Avprlb gene remains to be determined. One difficulty of functional studies on the Avprlb, especially its involvement in the HPA axis response to stress, which prompted the generation of Avprlb knockout (KO) mouse models, was the shortage of commercially available Avprlb ligands, particularly antagonists. Research on mice lacking functional Avprlbs has highlighted behavioural deficits in social memory and aggression. The Avprlb KO also appears to be an excellent model to study the contribution of the Avprlb in the HPA axis response to acute and perhaps some chronic (repeated) stressors where corticotrophin-releasing hormone and other genes involved in the HPA axis response to stress do not appear to compensate for the loss of the Avprlb

    Asymmetric triplex metallohelices with high and selective activity against cancer cells

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    Small cationic amphiphilic α-helical peptides are emerging as agents for the treatment of cancer and infection, but they are costly and display unfavourable pharmacokinetics. Helical coordination complexes may offer a three-dimensional scaffold for the synthesis of mimetic architectures. However, the high symmetry and modest functionality of current systems offer little scope to tailor the structure to interact with specific biomolecular targets, or to create libraries for phenotypic screens. Here, we report the highly stereoselective asymmetric self-assembly of very stable, functionalized metallohelices. Their anti-parallel head-to-head-to-tail ‘triplex’ strand arrangement creates an amphipathic functional topology akin to that of the active sub-units of, for example, host-defence peptides and ​p53. The metallohelices display high, structure-dependent toxicity to the human colon carcinoma cell-line HCT116 ​p53++, causing dramatic changes in the cell cycle without DNA damage. They have lower toxicity to human breast adenocarcinoma cells (MDA-MB-468) and, most remarkably, they show no significant toxicity to the bacteria methicillin-resistant Staphylococcus aureus and Escherichia coli. At a glanc

    Patient-centric trials for therapeutic development in precision oncology

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    An enhanced understanding of the molecular pathology of disease gained from genomic studies is facilitating the development of treatments that target discrete molecular subclasses of tumours. Considerable associated challenges include how to advance and implement targeted drug-development strategies. Precision medicine centres on delivering the most appropriate therapy to a patient on the basis of clinical and molecular features of their disease. The development of therapeutic agents that target molecular mechanisms is driving innovation in clinical-trial strategies. Although progress has been made, modifications to existing core paradigms in oncology drug development will be required to realize fully the promise of precision medicine

    Type 2 diabetes, socioeconomic status and life expectancy in Scotland (2012-2014):a population-based observational study

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    Aims/hypothesis: The aim of this study was to assess the role of socioeconomic status (SES) in the associations between type 2 diabetes and life expectancy in a complete national population. Methods: An observational population-based cohort study was performed using the Scottish Care Information – Diabetes database. Age-specific life expectancy (stratified by SES) was calculated for all individuals with type 2 diabetes in the age range 40–89 during the period 2012–2014, and for the remaining population of Scotland aged 40–89 without type 2 diabetes. Differences in life expectancy between the two groups were calculated. Results: Results were based on 272,597 individuals with type 2 diabetes and 2.75 million people without type 2 diabetes (total for 2013, the middle calendar year of the study period). With the exception of deprived men aged 80–89, life expectancy in people with type 2 diabetes was significantly reduced (relative to the type 2 diabetes-free population) at all ages and levels of SES. Differences in life expectancy ranged from −5.5 years (95% CI −6.2, −4.8) for women aged 40–44 in the second most-deprived quintile of SES, to 0.1 years (95% CI −0.2, 0.4) for men aged 85–89 in the most-deprived quintile of SES. Observed life-expectancy deficits in those with type 2 diabetes were generally greater in women than in men. Conclusions/interpretation: Type 2 diabetes is associated with reduced life expectancy at almost all ages and levels of SES. Elimination of life-expectancy deficits in individuals with type 2 diabetes will require prevention and management strategies targeted at all social strata (not just deprived groups)

    Degradation of metalaxyl and folpet by filamentous fungi isolated from Portuguese (Alentejo) vineyard soils

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    Degradation of xenobiotics by microbial populations is a potential method to enhance the effectiveness of ex situ or in situ bioremediation. The purpose of this study was to evaluate the impact of repeated metalaxyl and folpet treatments on soil microbial communities and to select soil fungal strains able to degrade these fungicides. Results showed enhanced degradation of metalaxyl and folpet in vineyards soils submitted to repeated treatments with these fungicides. Indeed, the greatest degradation ability was observed in vineyard soil samples submitted to greater numbers of treatments. Respiration activities, as determined in the presence of selective antibiotics in soil suspensions amended with metalaxyl and folpet, showed that the fungal population was the microbiota community most active in the degradation process. Batch cultures performed with a progressive increase of fungicide concentrations allowed the selection of five tolerant fungal strains: Penicillium sp. 1 and Penicillium sp. 2, mycelia sterila 1 and 3, and Rhizopus stolonifer. Among these strains, mycelium sterila 3 and R. stolonifer presented only in vineyard soils treated with repeated application of these fungicides and showed tolerance >1,000 mg l−1 against commercial formulations of metalaxyl (10 %) plus folpet (40 %). Using specific methods for inducing sporulation, mycelium sterila 3 was identified as Gongronella sp. Because this fungus is rare, it was compared using csM13-polymerase chain reaction (PCR) with the two known species, Gongronella butleri and G. lacrispora. The high tolerance to metalaxyl and folpet shown by Gongronella sp. and R. stolonifer might be correlated with their degradation ability. Our results point out that selected strains have potential for the bioremediation of metalaxyl and folpet in polluted soil sites

    What You See Is What You Get? Exclusion Performances in Ravens and Keas

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    BACKGROUND:Among birds, corvids and parrots are prime candidates for advanced cognitive abilities. Still, hardly anything is known about cognitive similarities and dissimilarities between them. Recently, exclusion has gained increasing interest in comparative cognition. To select the correct option in an exclusion task, one option has to be rejected (or excluded) and the correct option may be inferred, which raises the possibility that causal understanding is involved. However, little is yet known about its evolutionary history, as only few species, and mainly mammals, have been studied. METHODOLOGY/PRINCIPAL FINDINGS:We tested ravens and keas in a choice task requiring the search for food in two differently shaped tubes. We provided the birds with partial information about the content of one of the two tubes and asked whether they could use this information to infer the location of the hidden food and adjust their searching behaviour accordingly. Additionally, this setup allowed us to investigate whether the birds would appreciate the impact of the shape of the tubes on the visibility of food. The keas chose the baited tube more often than the ravens. However, the ravens applied the more efficient strategy, choosing by exclusion more frequently than the keas. An additional experiment confirmed this, indicating that ravens and keas either differ in their cognitive skills or that they apply them differently. CONCLUSION:To our knowledge, this is the first study to demonstrate that corvids and parrots may perform differently in cognitive tasks, highlighting the potential impact of different selection pressures on the cognitive evolution of these large-brained birds

    Effectiveness of PRECEDE model for health education on changes and level of control of HbA1c, blood pressure, lipids, and body mass index in patients with type 2 diabetes mellitus

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    <p>Abstract</p> <p>Background</p> <p>Individual health education is considered to be essential in the overall care of patients with type 2 diabetes (DM2), although there is some uncertainty regarding its metabolic control benefits. There have been very few randomized studies on the effects of individual education on normal care in DM2 patients with a control group, and none of these have assessed the long-term results. Therefore, this study aims to use this design to assess the effectiveness of the PRECEDE (Predisposing, Reinforcing, Enabling, Causes in Educational Diagnosis, and Evaluation) education model in the metabolic control and the reduction of cardiovascular risk factors, in patients with type 2 diabetes.</p> <p>Methods</p> <p>An open community effectiveness study was carried out in 8 urban community health centers in the North-East Madrid Urban Area (Spain). Six hundred patients with DM2 were randomized in two groups: PRECEDE or conventional model for health promotion education. The main outcome measures were glycated hemoglobin A1c, body mass index (BMI), blood pressure, lipids and control criteria during the 2-year follow-up period.</p> <p>Results</p> <p>Glycated hemoglobin A1c and systolic blood pressure (SBP) levels decreased significantly in the PRECEDE group (multivariate analysis of covariance, with baseline glycated hemoglobin A1c, SBP, and variables showing statistically significant differences between groups at baseline visits). The decrease levels in diastolic blood pressure (DBP), triglycerides and LDL cholesterol were nonsignificant. PRECEDE increased compliance in all control criteria, except for LDL cholesterol. BMI did not change during the study in either of the two models analyzed.</p> <p>Conclusions</p> <p>PRECEDE health education model is a useful method in the overall treatment in patients with type 2 diabetes, which contributes to decrease glycated hemoglobin A1c and SBP levels and increase the compliance in all the control criteria, except for LDL cholesterol.</p> <p>Trial registration number</p> <p>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01316367">NCT01316367</a></p

    Identification of pyrimethamine- and chloroquine-resistant Plasmodium falciparum in Africa between 1984 and 1998: genotyping of archive blood samples

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    <p>Abstract</p> <p>Background</p> <p>Understanding the geographical distribution of drug resistance of <it>Plasmodium falciparum </it>is important for the effective treatment of malaria. Drug resistance has previously been inferred mainly from records of clinical resistance. However, clinical resistance is not always consistent with the parasite's genetic resistance. Thus, molecular identification of the parasite's drug resistance is required. In Africa, clinical resistance to pyrimethamine (Pyr) and chloroquine (CQ) was evident before 1980 but few studies investigating the genetic resistance to these drugs were conducted before the late 1990s. In this study, genotyping of genes involved in resistance to Pyr and CQ was performed using archive blood samples from Africa between 1984 and 1998.</p> <p>Methods</p> <p>Parasite DNA was extracted from <it>P. falciparum</it>-infected blood smears collected from travellers returning to Japan from Africa between 1984 and 1998. Genotypes of the dihydrofolate reductase gene (<it>dhfr</it>) and CQ-resistance transporter gene (<it>pfcrt) </it>were determined by polymerase chain reaction amplification and sequencing.</p> <p>Results</p> <p>Genotyping of <it>dhfr </it>and <it>pfcrt </it>was successful in 59 and 80 samples, respectively. One wild-type and seven mutant <it>dhfr </it>genotypes were identified. Three <it>dhfr </it>genotypes lacking the S108N mutation (NRSI, ICSI, IRSI; amino acids at positions 51, 59, 108, and 164 with mutations underlined) were highly prevalent before 1994 but reduced after 1995, accompanied by an increase in genotypes with the S108N mutation. The <it>dhfr </it>IRNI genotype was first identified in Nigeria in 1991 in the present samples, and its frequency gradually increased. However, two double mutants (ICNI and NRNI), the latter of which was exclusively found in West Africa, were more frequent than the IRNI genotype. Only two <it>pfcrt </it>genotypes were found, the wild-type and a Southeast Asian type (CVIET; amino acids at positions 72-76 with mutations underlined). The CVIET genotype was already present as early as 1984 in Tanzania and Nigeria, and appeared throughout Africa between 1984 and 1998.</p> <p>Conclusions</p> <p>This study is the first to report the molecular identification of Pyr- and CQ-resistant genotypes of <it>P. falciparum </it>in Africa before 1990. Genotyping of <it>dhfr </it>and <it>pfcrt </it>using archive samples has revealed new aspects of the evolutionary history of Pyr- and CQ-resistant parasites in Africa.</p
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