727 research outputs found
Dose-dependent effects of Allopurinol on human foreskin fibroblast cell and human umbilical vein endothelial cell under hypoxia
Allopurinol, an inhibitor of xanthine oxidase, has been used in clinical trials of patients with cardiovascular and chronic kidney disease. These are two pathologies with extensive links to hypoxia and activation of the transcription factor hypoxia inducible factor (HIF) family. Here we analysed the effects of allopurinol treatment in two different cellular models, and their response to hypoxia. We explored the dose-dependent effect of allopurinol on Human Foreskin Fibroblasts (HFF) and Human Umbilical Vein Endothelial Cells (HUVEC) under hypoxia and normoxia. Under normoxia and hypoxia, high dose allopurinol reduced the accumulation of HIF-1α protein in HFF and HUVEC cells. Allopurinol had only marginal effects on HIF-1α mRNA level in both cellular systems. Interestingly, allopurinol effects over the HIF system were independent of prolyl-hydroxylase activity. Finally, allopurinol treatment reduced angiogenesis traits in HUVEC cells in an in vitro model. Taken together these results indicate that high doses of allopurinol inhibits the HIF system and pro-angiogenic traits in cells
Visual ecology of aphids – a critical review on the role of colours in host finding
We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms.
Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region.
We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours
that are not likely to hold. Finally we also discuss the
implications for developing and optimising strategies
of aphid control and monitoring
COPD diagnosis related to different guidelines and spirometry techniques
The aim was to compare the diagnosis of COPD among smokers according to different international guidelines and to compare the outcome when using slow (SVC) and forced vital capacity (FVC)
The LKB1-salt-inducible kinase pathway functions as a key gluconeogenic suppressor in the liver
LKB1 is a master kinase that regulates metabolism and growth through adenosine monophosphate-activated protein kinase (AMPK) and 12 other closely related kinases. Liver-specific ablation of LKB1 causes increased glucose production in hepatocytes in vitro and hyperglycaemia in fasting mice in vivo. Here we report that the salt-inducible kinases (SIK1, 2 and 3), members of the AMPK-related kinase family, play a key role as gluconeogenic suppressors downstream of LKB1 in the liver. The selective SIK inhibitor HG-9-91-01 promotes dephosphorylation of transcriptional co-activators CRTC2/3 resulting in enhanced gluconeogenic gene expression and glucose production in hepatocytes, an effect that is abolished when an HG-9-91-01-insensitive mutant SIK is introduced or LKB1 is ablated. Although SIK2 was proposed as a key regulator of insulin-mediated suppression of gluconeogenesis, we provide genetic evidence that liver-specific ablation of SIK2 alone has no effect on gluconeogenesis and insulin does not modulate SIK2 phosphorylation or activity. Collectively, we demonstrate that the LKB1-SIK pathway functions as a key gluconeogenic gatekeeper in the liver
Metformin mitigates the impaired development of skeletal muscle in the offspring of obese mice
Background: Maternal obesity is linked with offspring obesity and type 2 diabetes. Skeletal muscle (SM) insulin resistance is central to the development of diabetes. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is inhibited in SM of fetuses born to obese mothers
Infochemical-tritrophic Interactions of Soybean Aphids-host Plants-natural Enemies and Their Practical Applications in Pest Management
The soybean aphid, Aphis glycines Matsumura, is a newly invasive insect species that seriously threatens U.S. soybean production. This aphid pest has kept haunting many soybean growers by developing large colonies on soybeans in North America since 2000. Since its first appearance inWisconsin, it has spread to over half of US states and southern provinces in Canada. The heavy infestation of this pest whittles soybean growers’ profits and causes hundreds of million dollar losses. The present chapter will mainly describe efforts in studying aphid chemical ecology and sensory physiology for understanding how male aphids find their mates and host plants. It will also cover research efforts to understand host plant associated volatiles being used as cues for overwintering host plant location. In addition, findings on how soybean plant defensive system works against aphid infestation, as well as how those induced plant volatiles are used by aphid’s natural enemies for prey location will be presented. Finally, the use the basic understandings for developing useful tools for soybean aphid practical control will be discussed
Characterization of voltage-gated ionic currents in a peripheral sensory neuron in larval Drosophila.
BACKGROUND: The development, morphology and genetics of sensory neurons have been extensively studied in Drosophila. Sensory neurons in the body wall of larval Drosophila in particular have been the subject of numerous anatomical studies, however, little is known about the intrinsic electrical properties of larval sensory cells. FINDINGS: We performed whole cell patch recordings from an identified peripheral sensory cell, the dorsal bipolar sensory neuron (dbd) and measured voltage-gated ionic currents in 1st instar larvae. Voltage clamp analysis revealed that dbds have a TEA sensitive, non-inactivating IK type potassium current as well as a 4-AP sensitive, inactivating IA type potassium current. dbds also show a voltage-gated calcium current (ICa) and a voltage-gated sodium current (INa). CONCLUSIONS: This work provides a first characterization of voltage-activated ionic currents in an identified body-wall sensory neuron in larval Drosophila. Overall, we establish baseline physiology data for future studies aimed at understanding the ionic and genetic basis of sensory neuron function in fruit flies and other model organisms.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Cardiac biomarkers of prognostic importance in chronic obstructive pulmonary disease
Background: Ischemic heart disease is common in COPD and associated with worse prognosis. This study aimed to investigate the presence and prognostic impact of biomarkers of myocardial injury and ischemia among individuals with COPD and normal lung function, respectively. Methods: In 2002–04, all individuals with airway obstruction (FEV1/VC < 0.70, n = 993) were identified from population-based cohorts, together with age and sex-matched non-obstructive referents. At re-examination in 2005, spirometry, Minnesota-coded ECG and analyses of high-sensitivity cardiac troponin I (hs-cTnI) were performed in individuals with COPD (n = 601) and those with normal lung function (n = 755). Deaths were recorded until December 31st, 2010. Results: Hs-cTnI concentrations were above the risk stratification threshold of ≥5 ng/L in 31.1 and 24.9% of those with COPD and normal lung function, respectively. Ischemic ECG abnormalities were present in 14.8 and 13.4%, while 7.7 and 6.6% had both elevated hs-cTnI concentrations and ischemic ECG abnormalities. The 5-year cumulative mortality was higher in those with COPD than those with normal lung function (13.6% vs. 7.7%, p < 0.001). Among individuals with COPD, elevated hs-cTnI both independently and in combination with ischemic ECG abnormalities were associated with an increased risk for death (adjusted hazard ratio [HR]; 95% confidence interval [CI] 2.72; 1.46–5.07 and 4.54; 2.25–9.13, respectively). Similar associations were observed also among individuals with COPD without reported ischemic heart disease. Conclusions: In this study, elevated hs-cTnI concentrations in combination with myocardial ischemia on the electrocardiogram were associated with a more than four-fold increased risk for death in a population-based COPD-cohort, independent of disease severity
Resident interest and factors involved in entering a pediatric pulmonary fellowship
BACKGROUND: Relatively little is known about interest in pediatric pulmonology among pediatric residents. The purpose of this study, therefore, was to determine at this institution: 1) the level of pediatric resident interest in pursuing a pulmonary fellowship, 2) potential factors involved in development of such interest, 3) whether the presence of a pulmonary fellowship program affects such interest. METHODS: A questionnaire was distributed to all 52 pediatric residents at this institution in 1992 and to all 59 pediatric residents and 14 combined internal medicine/pediatrics residents in 2002, following development of a pulmonary fellowship program. RESULTS: Response rates were 79% in 1992 and 86% in 2002. Eight of the 43 responders in 1992 (19%) had considered doing a pulmonary fellowship compared to 7 of 63 (11%) in 2002. The highest ranked factors given by the residents who had considered a fellowship included wanting to continue one's education after residency, enjoying caring for pulmonary patients, and liking pulmonary physiology and the pulmonary faculty. Major factors listed by residents who had not considered a pulmonary fellowship included not enjoying the tracheostomy/ventilator population and chronic pulmonary patients in general, and a desire to enter general pediatrics or another fellowship. Most residents during both survey periods believed that they would be in non-academic or academic general pediatrics in 5 years. Only 1 of the 106 responding residents (~1%) anticipated becoming a pediatric pulmonologist. CONCLUSIONS: Although many pediatric residents consider enrolling in a pulmonary fellowship (~10–20% here), few (~1% here) will actually pursue a career in pediatric pulmonology. The presence of a pulmonary fellowship program did not significantly alter resident interest, though other confounding factors may be involved
- …