276 research outputs found
The impact of mycorrhizal symbiosis on tomato fruit quality
The project investigates the potential impact of mycorrhizal fungi, which have been acknowledged as a new class of bio-fertilizers, on the quality of vegetables. To verify such a hypothesis, we selected tomato (Solanum lycopersicum) as a model plant to examine whether the beneficial effects of mycorrhizal fungi on plant development may be extended to some qualitative fruit features. As a second step, five genes related to carotenoid biosynthesis and volatile compounds were selected. Their expression was investigated through a real-time RT-PCR comparison of mycorrhized and non-mycorrhized plants
Examining the Bacterial Methionine Transporter Utilizing Soluble Lipid Bilayer Systems
ATP-binding cassette (ABC) transporters are ubiquitous across all kingdoms of life. These highly specific pumps translocate substrates across cell membranes through the energy from ATP binding and hydrolysis. A detailed understanding of ABC transporter mechanism could aid in the treatment of a variety of human disorders in which ABC transporters are defective such as cystic fibrosis. While the structural determinations of ABC transporters have provided critical insights, a detailed molecular understanding of how these proteins work has been precluded by difficulties in the functional study of transporters such as unstable âsubstituteâ mimetic environments. To address this issue, we have turned to a system called nanodiscs, which is a discoidal lipid bilayer encircled by a protein helical belt. Unlike liposomes, nanodiscs have been shown to be a viable system for fluorescent spectroscopic analysis. In preparation for, and as subject to, these kind of analyses, this system has been experimentally proven to be durable in a wide range of experimental conditions, including pH, temperature, and salt concentration
DiversitÀt in der F5 von dynamisch evolvierenden Weizen Composite Cross Populationen
Three winter wheat composite cross (CC) populations were created in 2001 in the UK
consisting either of 20 modern wheat parents (called A Population), a subset of 12
high quality parents (Q), or a subset of 9 high yielding parents (Y). Seed of the F4 was
transferred to the University of Kassel in 2005 and the populations were grown since
then under organic and conventional conditions in well separated large (>100m2) plots
in two parallel sets (12 populations total) without conscious selection applied. In the
conventional system fungicides and insecticides were not applied to expose the
populations to natural pest and disease pressure. Morphological diversity, diseases,
and yield were assessed in the field every season. The parents and a total of 1379
single plants of 23 single seed progenies of the F5 were tested in the laboratory for
their combined resistance to three brown rust isolates. Only one progeny was
homogenous in reaction, all others were mixtures of two to eight three-locus
genotypes. Despite the supposed inbreeding structure of wheat one association in the
Q progenies was random suggesting recent out-crossing. Thus, diversity and
heterogeneity was still high in the F6 with evidence that out-crossing still played a role
and contributed to this heterogeneity
Assessing Communities of Practice in health policy : A conceptual framework as a first step towards empirical research
Peer reviewe
WNT signaling regulates self-renewal and differentiation of prostate cancer cells with stem cell characteristics
Prostate cancer cells with stem cell characteristics were identified in human prostate cancer cell lines by their ability to form from single cells self-renewing prostaspheres in non-adherent cultures. Prostaspheres exhibited heterogeneous expression of proliferation, differentiation and stem cell-associated makers CD44, ABCG2 and CD133. Treatment with WNT inhibitors reduced both prostasphere size and self-renewal. In contrast, addition of Wnt3a caused increased prostasphere size and self-renewal, which was associated with a significant increase in nuclear Î-catenin, keratin 18, CD133 and CD44 expression. As a high proportion of LNCaP and C4-2B cancer cells express androgen receptor we determined the effect of the androgen receptor antagonist bicalutamide. Androgen receptor inhibition reduced prostasphere size and expression of PSA, but did not inhibit prostasphere formation. These effects are consistent with the androgen-independent self-renewal of cells with stem cell characteristics and the androgen-dependent proliferation of transit amplifying cells. As the canonical WNT signaling effector Î-catenin can also associate with the androgen receptor, we propose a model for tumour propagation involving a balance between WNT and androgen receptor activity. That would affect the self-renewal of a cancer cell with stem cell characteristics and drive transit amplifying cell proliferation and differentiation. In conclusion, we provide evidence that WNT activity regulates the self-renewal of prostate cancer cells with stem cell characteristics independently of androgen receptor activity. Inhibition of WNT signaling therefore has the potential to reduce the self-renewal of prostate cancer cells with stem cell characteristics and improve the therapeutic outcome.Peer reviewe
On the avoidability of breast cancer in industrialized societies: older mean age at first birth as an indicator of excess breast cancer risk
Background Breast cancer incidence continuous to increase. We examined at population level the association between the relative excess risk of breast cancer and previous age of mother at first birth. Method Incidence of breast cancer in 34 industrialized countries was obtained from the GLOBOCAN 2002 and SEER databases. Data on age of mother at first birth was collected through national statistics offices. National relative excess risk (RER) was calculated by subtracting the lowest age-specific incidence rate from the rate in each population, and dividing the difference by the latter. Results The national RER in 2002 correlated closely with a higher average age at first birth in 1972, 1982, 1992 and also 2002, Pearson correlation [r] being 0.83, 0.79, 0.72 and 0.61, respectively; PÂ <Â 0.0001. RER of breast cancer in 2002 for those aged 15â44Â years correlated closely with the mean age at first birth in 1982 and 1992 (r: 0.81 and 0.75; PÂ <Â 0.0001), whereas RER for those aged 45â54Â years correlated strongly with age at first birth in 1972 and 1982 (r: 0.81 and 0.76; PÂ <Â 0.0001), and for those aged 55â64Â years with age at first birth in 1972 (r: 0.77; PÂ <Â 0.0001). Conclusions The rising age at first childbirth of mothers has been followed by marked increases in breast cancer incidence. Later age at first birth seems to characterize secular diffusion of âmodernâ lifestyles with a potentially large impact on increased breast cancer risk, and hence should be accompanied by greater opportunities for prevention through modifiable risk factors
Sodium/myo-Inositol Transporters: Substrate Transport Requirements and Regional Brain Expression in the TgCRND8 Mouse Model of Amyloid Pathology
Inositol stereoisomers, myo- and scyllo-inositol, are known to enter the brain and are significantly elevated following oral administration. Elevations in brain inositol levels occur across a concentration gradient as a result of active transport from the periphery. There are two sodium/myo-inositol transporters (SMIT1, SMIT2) that may be responsible for regulating brain inositol levels. The goals of this study were to determine the effects of aging and Alzheimer's disease (AD)-like amyloid pathology on transporter expression, to compare regional expression and to analyze substrate requirements of the inositol transporters. QPCR was used to examine expression of the two transporters in the cortex, hippocampus and cerebellum of TgCRND8 mice, a mouse model of amyloid pathology, in comparison to non-transgenic littermates. In addition, we examined the structural features of inositol required for active transport, utilizing a cell-based competitive uptake assay. Disease pathology did not alter transporter expression in the cortex or hippocampus (p>0.005), with only minimal effects of aging observed in the cerebellum (SMIT1: F2,26â=â12.62; pâ=â0.0002; SMIT2: F2,26â=â8.71; pâ=â0.0015). Overall, brain SMIT1 levels were higher than SMIT2, however, regional differences were observed. For SMIT1, at 4 and 6 months cerebellar SMIT1 levels were significantly higher than cortical and hippocampal levels (p<0.05). For SMIT2, at all three ages both cortical and cerebellar SMIT2 levels were significantly higher than hippocampal levels (p<0.05) and at 4 and 6 months of age, cerebellar SMIT2 levels were also significantly higher than cortical levels (p<0.05). Inositol transporter levels are stably expressed as a function of age, and expression is unaltered with disease pathology in the TgCRND8 mouse. Given the fact that scyllo-inositol is currently in clinical trials for the treatment of AD, the stable expression of inositol transporters regardless of disease pathology is an important finding
Understanding the prescription of antidepressants: a Qualitative study among French GPs
<p>Abstract</p> <p>Background</p> <p>One-tenth of France's population is prescribed at least one antidepressant, primarily by General Practitioners. The reasons for this high prescription rate remain unclear. One-third of these prescriptions may not comply with clinical practice guidelines, and 20% are potentially unrelated to any psychiatric condition. Our aim was to explore how GPs declare they use antidepressants in daily practice and understand their reasons for prescribing them.</p> <p>Method</p> <p>Six focus groups including a total of 56 rural and urban GPs, with four interviews were performed. The topic guide focused on reasons for prescribing antidepressants in various primary care situations. Phenomenological analysis was performed by four researchers.</p> <p>Results</p> <p>Antidepressants were seen as useful and not harmful. Personal assessment based on experience and feeling determined the GPs' decisions rather than the use of scales. Twenty-four "non-psychiatric" conditions possibly leading to prescription of antidepressants in primary care were found.</p> <p>Conclusions</p> <p>The GPs reported prescribing antidepressants for a wide range of conditions other than depression. The GPs' decision making process is difficult and complex. They seemed to prefer to focus on their difficulties in diagnosing depression rather than on useless overtreatment. Instead of using the guidelines criteria to detect potential cases of useful prescription, physicians tend to use their own tools based on gut feelings, knowledge of the patient and contextual issues.</p
French Pregnancy Physical Activity Questionnaire Compared with an Accelerometer Cut Point to Classify Physical Activity among Pregnant Obese Women
Given the high risk for inactivity during pregnancy in obese women, validated questionnaires for physical activity (PA) assessment in this specific population is required before evaluating the effect of PA on perinatal outcomes. No questionnaire was validated in pregnant obese women. The Pregnancy Physical Activity Questionnaire (PPAQ) has been designed based on activities reported during pregnancy and validated in pregnant women. We translated the PPAQ to French and assessed reliability and accuracy of this French version among pregnant obese women. In this cross-sectional study, pregnant obese women were evenly recruited at the end of each trimester of pregnancy. They completed the PPAQ twice, with an interval of 7 days in-between, to recall PA of the last three months. Between PPAQ assessments, participants wore an accelerometer (Actigraph GT1M) during 7 consecutive days. Fourty-nine (49) pregnant obese women (29.8±4.2 yrs, 34.7±5.1 kg.mâ2) participated to the study. The intraclass correlation coefficients (ICCs) between the two PPAQ assessments were 0.90 for total activity, 0.86 for light and for moderate intensity, and 0.81 for vigorous intensity activities. It ranged from 0.59 for âTransportationâ to 0.89 for âHousehold and Caregivingâ activities. Spearman correlation coefficients (SCCs) between the PPAQ and the Matthewsâ cut point used to classify an activity of moderate and above intensity were 0.50 for total activity, 0.25 for vigorous intensity and 0.40 for moderate intensity. The correlations between the PPAQ and the accelerometer counts were 0.58 for total activity, 0.39 for vigorous intensity and 0.49 for moderate intensity. The highest SCCs were for âOccupationâ and âHousehold and Caregivingâ activities. Comparisons with other standard cutpoints were presented in files S1, S2, S3, S4, S5, S6, S7. The PPAQ is reliable and moderately accurate for the measure of PA of various intensities and types among pregnant obese women
Antibodies Targeted to the Brain with Image-Guided Focused Ultrasound Reduces Amyloid-ÎČ Plaque Load in the TgCRND8 Mouse Model of Alzheimer's Disease
Immunotherapy for Alzheimer's disease (AD) relies on antibodies directed against toxic amyloid-beta peptide (AÎČ), which circulate in the bloodstream and remove AÎČ from the brain [1], [2]. In mouse models of AD, the administration of anti-AÎČ antibodies directly into the brain, in comparison to the bloodstream, was shown to be more efficient at reducing AÎČ plaque pathology [3], [4]. Therefore, delivering anti-AÎČ antibodies to the brain of AD patients may also improve treatment efficiency. Transcranial focused ultrasound (FUS) is known to transiently-enhance the permeability of the blood-brain barrier (BBB) [5], allowing intravenously administered therapeutics to enter the brain [6]â[8]. Our goal was to establish that anti-AÎČ antibodies delivered to the brain using magnetic resonance imaging-guided FUS (MRIgFUS) [9] can reduce plaque pathology. To test this, TgCRND8 mice [10] received intravenous injections of MRI and FUS contrast agents, as well as anti-AÎČ antibody, BAM-10. MRIgFUS was then applied transcranially. Within minutes, the MRI contrast agent entered the brain, and BAM-10 was later found bound to AÎČ plaques in targeted cortical areas. Four days post-treatment, AÎČ pathology was significantly reduced in TgCRND8 mice. In conclusion, this is the first report to demonstrate that MRIgFUS delivery of anti-AÎČ antibodies provides the combined advantages of using a low dose of antibody and rapidly reducing plaque pathology
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