200 research outputs found
Molecular characterization and analysis of the acrB gene of Aspergillus nidulans: A gene identified by genetic interaction as a component of the regulatory network that includes the CreB deubiquitination enzyme
Copyright © 2003 by the Genetics Society of AmericaMutations in the acrB gene, which were originally selected through their resistance to acriflavine, also result in reduced growth on a range of sole carbon sources, including fructose, cellobiose, raffinose, and starch, and reduced utilization of ω-amino acids, including GABA and ß-alanine, as sole carbon and nitrogen sources. The acrB2 mutation suppresses the phenotypic effects of mutations in the creB gene that encodes a regulatory deubiquitinating enzyme, and in the creC gene that encodes a WD40-repeat-containing protein. Thus AcrB interacts with a regulatory network controlling carbon source utilization that involves ubiquitination and deubiquitination. The acrB gene was cloned and physically analyzed, and it encodes a novel protein that contains three putative transmembrane domains and a coiled-coil region. AcrB may play a role in the ubiquitination aspect of this regulatory network.Natasha A. Boase, Robin A. Lockington, Julian R. J. Adams, Louise Rodbourn and Joan M. Kell
The microbiome of chronic rhinosinusitis: culture, molecular diagnostics and biofilm detection
Background: Bacteria and fungi are believed to influence mucosal inflammation in chronic rhinosinusitis (CRS). However their presence and relationship to disease is debated. This study used multiple detection methods to compare microbial diversity and microbial abundance in healthy and diseased sinonasal mucosa. The utility of contemporary detection methods is also examined. Methods: Sinonasal mucosa was analyzed from 38 CRS and 6 controls. Bacterial and fungal analysis was performed using conventional culture, molecular diagnostics (polymerase chain reaction coupled with electrospray ionization time-of-flight mass spectrometry) and fluorescence in situ hybridization. Results: Microbes were detected in all samples, including controls, and were often polymicrobial. 33 different bacterial species were detected in CRS, 5 in control patients, with frequent recovery of anaerobes. Staphylococcus aureus and Propionibacterium acnes were the most common organisms in CRS and controls, respectively. Using a model organism, FISH had a sensitivity of 78%, and a specificity of 93%. Many species were detected in both CRS and controls however, microbial abundance was associated with disease manifestation. Conclusions: This study highlights some cornerstones of microbial variations in healthy and diseased paranasal sinuses. Whilst the healthy sinus is clearly not sterile, it appears prevalence and abundance of organisms is critical in determining disease. Evidence from high-sensitivity techniques, limits the role of fungi in CRS to a small group of patients. Comparison with molecular analysis suggests that the detection threshold of FISH and culture is related to organism abundance and, furthermore, culture tends to select for rapidly growing organisms.Sam Boase, Andrew Foreman, Edward Cleland, Lorwai Tan, Rachel Melton-Kreft, Harshita Pant, Fen Z Hu, Garth D Ehrlich and Peter-John Wormal
Mass spectrometry-directed structure elucidation and total synthesis of ultra-long chain (O-acyl)-ω-hydroxy fatty acids
The (O-acyl)-ω-hydroxy FAs (OAHFAs) comprise an unusual lipid subclass present in the skin, vernix caseosa, and meibomian gland secretions. Although they are structurally related to the general class of FA esters of hydroxy FAs (FAHFAs), the ultra-long chain (30-34 carbons) and the putative -substitution of the backbone hydroxy FA suggest that OAHFAs have unique biochemistry. Complete structural elucidation of OAHFAs has been challenging because of their low abundance within complex lipid matrices. Furthermore, because these compounds occur as a mixture of closely related isomers, insufficient spectroscopic data have been obtained to guide structure confirmation by total synthesis. Here, we describe the full molecular structure of ultra-long chain OAHFAs extracted from human meibum by exploiting the gas-phase purification of lipids through multistage MS and novel multidimensional ion activation methods. The analysis elucidated sites of unsaturation, the stereochemical configuration of carbon-carbon double bonds, and ester linkage regiochemistry. Such isomer-resolved MS guided the first total synthesis of an ultra-long chain OAHFA, which, in turn, confirmed the structure of the most abundant OAHFA found in human meibum, OAHFA 50:2. The availability of a synthetic OAHFA opens new territory for future investigations into the unique biophysical and biochemical properties of these lipids
Outbreeding effects in an inbreeding insect, Cimex lectularius
In some species, populations with few founding individuals can be resilient to extreme inbreeding. Inbreeding seems to be the norm in the common bed bug, Cimex lectularius, a flightless insect that, nevertheless, can reach large deme sizes and persist successfully. However, bed bugs can also be dispersed passively by humans, exposing inbred populations to gene flow from genetically distant populations. The introduction of genetic variation through this outbreeding could lead to increased fitness (heterosis) or be costly by causing a loss of local adaptation or exposing genetic incompatibility between populations (outbreeding depression). Here, we addressed how inbreeding within demes and outbreeding between distant populations impact fitness over two generations in this re‐emerging public health pest. We compared fitness traits of families that were inbred (mimicking reproduction following a founder event) or outbred (mimicking reproduction following a gene flow event). We found that outbreeding led to increased starvation resistance compared to inbred families, but this benefit was lost after two generations of outbreeding. No other fitness benefits of outbreeding were observed in either generation, including no differences in fecundity between the two treatments. Resilience to inbreeding is likely to result from the history of small founder events in the bed bug. Outbreeding benefits may only be detectable under stress and when heterozygosity is maximized without disruption of coadaptation. We discuss the consequences of these results both in terms of inbreeding and outbreeding in populations with genetic and spatial structuring, as well as for the recent resurgence of bed bug populations
Socioeconomic drivers of urban pest prevalence
Funding: We thank the National Socio-Environmental Synthesis Center (SESYNC) under funding received from the National Science Foundation DBI-1052875, for supporting the workshop series ‘Socio-Spatial Ecology of the Bed Bug and its Control'.1. Bed bugs have re-established themselves as a common household pest in the United States and pose significant public health and economic concerns, particularly in urban areas. 2. Documenting the scale of the bed bug resurgence and identifying the underlying predictors of the spatial patterns of their incidence is challenging, largely because available data come from biased self-reporting through local government code enforcement. 3. Here, we make use of a novel source of systematically collected data from periodic inspections of multifamily housing units in Chicago to investigate neighbourhood drivers of bed bug infestation prevalence in Chicago. 4. Bed bug infestations are strongly associated with income, eviction rates and crowding at the neighbourhood level. 5. That bed bug prevalence is higher in lower-income neighbourhoods with higher levels of household crowding and eviction notices provides unique empirical evidence of the disproportionate allocation of public health burdens upon neighbourhoods facing multiple dimensions of disadvantage.Publisher PDFPeer reviewe
Comt1 genotype and expression predicts anxiety and nociceptive sensitivity in inbred strains of mice
Catechol-O-methyltransferase (COMT) is an ubiquitously expressed enzyme that maintains basic biologic functions by inactivating catechol substrates. In humans, polymorphic variance at the COMT locus has been associated with modulation of pain sensitivity (Andersen & Skorpen, 2009) and risk for developing psychiatric disorders (Harrison & Tunbridge, 2008). A functional haplotype associated with increased pain sensitivity was shown to result in decreased COMT activity by altering mRNA secondary structure-dependent protein translation (Nackley et al., 2006). However, the exact mechanisms whereby COMT modulates pain sensitivity and behavior remain unclear and can be further studied in animal models. We have assessed Comt1 gene expression levels in multiple brain regions in inbred strains of mice and have discovered that Comt1 is differentially expressed among the strains, and this differential expression is cis-regulated. A B2 Short Interspersed Element (SINE) was inserted in the 3′UTR of Comt1 in 14 strains generating a common haplotype that correlates with gene expression. Experiments using mammalian expression vectors of full-length cDNA clones with and without the SINE element demonstrate that strains with the SINE haplotype (+SINE) have greater Comt1 enzymatic activity. +SINE mice also exhibit behavioral differences in anxiety assays and decreased pain sensitivity. These results suggest that a haplotype, defined by a 3′ UTR B2 SINE element, regulates Comt1 expression and some mouse behaviors
Researchers combat resurgence of bed bug in behavioral studies and monitor trials
The worldwide resurgence of bed bugs has recently created urban pest challenges in California. Regardless of information source — newspaper, Internet, television, university or government — the message is the same: bed bugs are back, and with a vengeance. Until recently, the pest's longstanding rarity and a historical reliance on pesticide-based management have not encouraged research and public education to develop and make available current information on bed bug biology, detection and control. UC is currently directing comprehensive, collaborative programs of research and education to combat this emerging nuisance and public health threat. Laboratory and field tests were conducted by UC researchers on several commercial bed bug monitors and confirm that additional research is needed to improve the performance of existing monitors and to develop new ones
A cognitive perspective on equivalent effect: using eye tracking to measure equivalence in source text and target text cognitive effects on readers
Eye-tracking methods have long been used to explore cognitive processing in reading, but the recent burgeoning of such methods in the field of translation studies has focused almost entirely on the translation process or audiovisual translation, neglecting the effects of the translation product itself. This paper presents a proof-of-concept study using eye tracking to compare fixation data between native readers of a French literary source text and native readers of its English translation at specific, corresponding points in the texts. The preliminary data are consistent with previous findings on the relationship between the features of the fixated word and fixation durations. These findings are also consistent with stylistic analyses and indicate that this method can be used to compare the levels of cognitive effort between two readership groups in order to investigate whether their experience is similar – whether an ‘equivalent effect’ has been achieved – thus contributing to the ongoing discourse surrounding equivalence in translation studies
Communication and marketing as tools to cultivate the public's health: a proposed "people and places" framework
<p>Abstract</p> <p>Background</p> <p>Communication and marketing are rapidly becoming recognized as core functions, or core competencies, in the field of public health. Although these disciplines have fostered considerable academic inquiry, a coherent sense of precisely how these disciplines can inform the practice of public health has been slower to emerge.</p> <p>Discussion</p> <p>In this article we propose a framework – based on contemporary ecological models of health – to explain how communication and marketing can be used to advance public health objectives. The framework identifies the attributes of people (as individuals, as social networks, and as communities or populations) and places that influence health behaviors and health. Communication, i.e., the provision of information, can be used in a variety of ways to foster beneficial change among both people (e.g., activating social support for smoking cessation among peers) and places (e.g., convincing city officials to ban smoking in public venues). Similarly, marketing, i.e., the development, distribution and promotion of products and services, can be used to foster beneficial change among both people (e.g., by making nicotine replacement therapy more accessible and affordable) and places (e.g., by providing city officials with model anti-tobacco legislation that can be adapted for use in their jurisdiction).</p> <p>Summary</p> <p>Public health agencies that use their communication and marketing resources effectively to support people in making healthful decisions and to foster health-promoting environments have considerable opportunity to advance the public's health, even within the constraints of their current resource base.</p
Deletion of Nedd4-2 results in progressive kidney disease in mice
NEDD4-2 (NEDD4L), a ubiquitin protein ligase of the Nedd4 family, is a key regulator of cell surface expression and activity of the amiloride-sensitive epithelial Na⁺ channel (ENaC). While hypomorphic alleles of Nedd4-2 in mice show salt-sensitive hypertension, complete knockout results in pulmonary distress and perinatal lethality due to increased cell surface levels of ENaC. We now show that Nedd4-2 deficiency in mice also results in an unexpected progressive kidney injury phenotype associated with elevated ENaC and Na⁺Cl⁻ cotransporter expression, increased Na⁺ reabsorption, hypertension and markedly reduced levels of aldosterone. The observed nephropathy is characterized by fibrosis, tubule epithelial cell apoptosis, dilated/cystic tubules, elevated expression of kidney injury markers and immune cell infiltration, characteristics reminiscent of human chronic kidney disease. Importantly, we demonstrate that the extent of kidney injury can be partially therapeutically ameliorated in mice with nephron-specific deletions of Nedd4-2 by blocking ENaC with amiloride. These results suggest that increased Na⁺ reabsorption via ENaC causes kidney injury and establish a novel role of NEDD4-2 in preventing Na⁺-induced nephropathy. Contrary to some recent reports, our data also indicate that ENaC is the primary in vivo target of NEDD4-2 and that Nedd4-2 deletion is associated with hypertension on a normal Na⁺ diet. These findings provide further insight into the critical function of NEDD4-2 in renal pathophysiology.Tanya L Henshall, Jantina A Manning, Omri S Alfassy, Pranay Goel, Natasha A Boase, Hiroshi Kawabe and Sharad Kuma
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