3,032 research outputs found
Glutathione transferases in soybean glycine max (L.) Merr
Glutathione transferases, also known as Glutathione S-transferases (GSTs), are a diverse group of enzymes that catalyse the conjugation of the tri-peptide glutathione to a wide range of electrophilic substrates. Their biological function in endogenous metabolism in plants is not well characterised, although their role in herbicide metabolism and herbicide selectivity is well documented. Many herbicides used in soybean. Glycine max (L.) Merr., are selective against weeds due to their rapid detoxification in the crop through conjugation with homoglutathione (γ-glu-cys-β-ala), the predominant free thiol in many legumes. However, an in depth characterisation of the GSTs which can potentially catalyse these reactions in soybean has never been performed. This work describes the biochemical and molecular characterisation of GSTs in soybean with emphasis on the identification of specific isoenzymes involved in herbicide metabolism. GST activity toward the chloroacetanilide herbicides acetochlor and metolachlor, the diphenyl ethers acifluorfen and fomesafen and the sulphonyl urea chlorimuron-ethyl were all detected in crude protein extracts from five-day-old suspension cultured soybean cells. GST activity was also determined in five-day-old soybean seedlings, though this activity was significantly lower than that observed with the cell suspension cultures. Treatment of soybean plants with herbicides and herbicide safeners resulted in increased GST activity toward the model substrate l-chloro-2,4-dinitrobenzene (CDNB), but no change in activity toward herbicide substrates. In both plant and cell cultures GST-catalysed conjugation of the diphenyl ethers acifluorfen and fomesafen was over five-fold greater in the presence of homoglutathione as compared with glutathione. The preferential detoxification of these herbicides in the presence of homoglutathione appeared to be an important determinant of their rapid detoxification in soybean and an important factor in herbicide selectivity. GSTs were purified from five-day-old soybean cell cultures using S-hexylglutathione affinity chromatography and anion-exchange chromatography. A combination of reversed-phase HPLC, SDS-PAGE and MALDI-TOF mass spectrometry of the purified fractions indicated the presence of nine putative GST subunits, each with a molecular mass between 25 and 29 kDa. Soybean GST cDNA clones were obtained using a combination of RT-PCR, utilising degenerate oligonucleotides designed to conserved regions within plant GSTs, and screening of cDNA libraries prepared from soybean plants and cell cultures. This process failed to identify any theta-type GSTs, the class associated with herbicide detoxification in maize. In contrast, seven distinct tau-type GSTs were isolated together with a number of clones showing minor variations in individual sequences. Expression of these cDNAs in Escherichia coli showed the purified recombinant GSTs were active toward a diverse range of substrates, and possessed additional glutathione peroxidase activity. GST activities for each recombinant enzyme varied with substrate and thiol type, with a marked preference for homoglutathione with selected substrates. From the work reported in this study it would appear that the tau-type GSTs of soybean are at least as complex as those previously reported in cereals and have an important role in determining herbicide metabolism and selectivity in this major crop
Porcine Neonatal Coccidiosis: A Clinical Review
Coccidiosis in neonatal swine is a clinical disease syndrome, associated with infection of the obligate intracellular parasite Isospora suis. Isospora suis infection, with or without concurrent infection of other porcine enteropathogens, is responsible for a significant portion of enteric disease in neonatal swine
Palliative care services in families of males with muscular dystrophy: Data from MD STARnet
Introduction: Information on use of palliative care services among individuals with Duchenne and Becker muscular dystrophy is scant despite the clearly documented need. Methods: We examined associations between uptake of palliative care services by 233 males with Duchenne and Becker muscular dystrophy aged 12 and older for both caregiver and affected male characteristics using the Muscular Dystrophy Surveillance Tracking and Research Network baseline interview. Results: Ninety-one percent of caregivers (213/233) used at least one palliative care service. Case management had the highest frequency of use (59%). Use of palliative care was more frequently associated with the characteristics of affected males, as were some individual palliative care services. Utilization of six individual services differed among Muscular Dystrophy Surveillance Tracking and Research Network sites. While research suggests that pain is a frequent problem in Duchenne and Becker muscular dystrophy, only 12.5% reported use of pain management services. Discussion: Although palliative care use among families of males with Duchenne and Becker muscular dystrophy is high overall, there is much variability in use of individual services. Use of palliative care is driven by disease experience in the affected male. Many of the care recommendations for these individuals highlight the importance for early involvement of palliative care professionals.Centers for Disease Control and Prevention [DD000187, DD000189, DD000190, DD000191]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Methadone-induced mortality in the treatment of chronic pain: Role of QT prolongation
Methadone is increasingly prescribed for chronic pain, yet the associated mortality appears to be
rising disproportionately relative to other opioid analgesics. We review the available evidence on
methadone-associated mortality, and explore potential pharmacokinetic and pharmacodynamic
explanations for its greater apparent lethality. While methadone shares properties of central
nervous system and respiratory depression with other opioids, methadone is unique as a potent
blocker of the delayed rectifier potassium ion channel (IKr). This results in QT-prolongation
and torsade de pointes (TdP) in susceptible individuals. In some individuals with low serum
protein binding of methadone, the extent of blockade is roughly comparable to that of sotalol,
a potent QT-prolonging drug. Predicting an individual’s propensity for methadone-induced
TdP is difficult at present given the inherent limitations of the QT interval as a risk-stratifier
combined with the multifactorial nature of the arrhythmia. Consensus recommendations have
recently been published to mitigate the risk of TdP until further studies better define the
arrhythmia risk factors for methadone. Studies are needed to provide insights into the clinical
covariates most likely to result in methadone-associated arrhythmia and to assess the feasibility
of current risk mitigation strategies
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Aberrant Lymphatic Endothelial Progenitors in Lymphatic Malformation Development
Lymphatic malformations (LMs) are vascular anomalies thought to arise from dysregulated lymphangiogenesis. These lesions impose a significant burden of disease on affected individuals. LM pathobiology is poorly understood, hindering the development of effective treatments. In the present studies, immunostaining of LM tissues revealed that endothelial cells lining aberrant lymphatic vessels and cells in the surrounding stroma expressed the stem cell marker, CD133, and the lymphatic endothelial protein, podoplanin. Isolated patient-derived CD133+ LM cells expressed stem cell genes (NANOG, Oct4), circulating endothelial cell precursor proteins (CD90, CD146, c-Kit, VEGFR-2), and lymphatic endothelial proteins (podoplanin, VEGFR-3). Consistent with a progenitor cell identity, CD133+ LM cells were multipotent and could be differentiated into fat, bone, smooth muscle, and lymphatic endothelial cells in vitro. CD133+ cells were compared to CD133− cells isolated from LM fluids. CD133− LM cells had lower expression of stem cell genes, but expressed circulating endothelial precursor proteins and high levels of lymphatic endothelial proteins, VE-cadherin, CD31, podoplanin, VEGFR-3 and Prox1. CD133− LM cells were not multipotent, consistent with a differentiated lymphatic endothelial cell phenotype. In a mouse xenograft model, CD133+ LM cells differentiated into lymphatic endothelial cells that formed irregularly dilated lymphatic channels, phenocopying human LMs. In vivo, CD133+ LM cells acquired expression of differentiated lymphatic endothelial cell proteins, podoplanin, LYVE1, Prox1, and VEGFR-3, comparable to expression found in LM patient tissues. Taken together, these data identify a novel LM progenitor cell population that differentiates to form the abnormal lymphatic structures characteristic of these lesions, recapitulating the human LM phenotype. This LM progenitor cell population may contribute to the clinically refractory behavior of LMs
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Aberrant Lymphatic Endothelial Progenitors in Lymphatic Malformation Development
Lymphatic malformations (LMs) are vascular anomalies thought to arise from dysregulated lymphangiogenesis. These lesions impose a significant burden of disease on affected individuals. LM pathobiology is poorly understood, hindering the development of effective treatments. In the present studies, immunostaining of LM tissues revealed that endothelial cells lining aberrant lymphatic vessels and cells in the surrounding stroma expressed the stem cell marker, CD133, and the lymphatic endothelial protein, podoplanin. Isolated patient-derived CD133+ LM cells expressed stem cell genes (NANOG, Oct4), circulating endothelial cell precursor proteins (CD90, CD146, c-Kit, VEGFR-2), and lymphatic endothelial proteins (podoplanin, VEGFR-3). Consistent with a progenitor cell identity, CD133+ LM cells were multipotent and could be differentiated into fat, bone, smooth muscle, and lymphatic endothelial cells in vitro. CD133+ cells were compared to CD133− cells isolated from LM fluids. CD133− LM cells had lower expression of stem cell genes, but expressed circulating endothelial precursor proteins and high levels of lymphatic endothelial proteins, VE-cadherin, CD31, podoplanin, VEGFR-3 and Prox1. CD133− LM cells were not multipotent, consistent with a differentiated lymphatic endothelial cell phenotype. In a mouse xenograft model, CD133+ LM cells differentiated into lymphatic endothelial cells that formed irregularly dilated lymphatic channels, phenocopying human LMs. In vivo, CD133+ LM cells acquired expression of differentiated lymphatic endothelial cell proteins, podoplanin, LYVE1, Prox1, and VEGFR-3, comparable to expression found in LM patient tissues. Taken together, these data identify a novel LM progenitor cell population that differentiates to form the abnormal lymphatic structures characteristic of these lesions, recapitulating the human LM phenotype. This LM progenitor cell population may contribute to the clinically refractory behavior of LMs.</p
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The onset of neoglaciation in Iceland and the 4.2 ka event
Publisher's version (útgefin grein)Strong similarities in Holocene climate reconstructions derived from multiple proxies (BSi, TOC – total organic carbon, δ13C, C∕N, MS – magnetic susceptibility, δ15N) preserved in sediments from both glacial and non-glacial lakes across Iceland indicate a relatively warm early to mid Holocene from 10 to 6 ka, overprinted with cold excursions presumably related to meltwater impact on North Atlantic circulation until 7.9 ka. Sediment in lakes from glacial catchments indicates their catchments were ice-free during this interval. Statistical treatment of the high-resolution multi-proxy paleoclimate lake records shows that despite great variability in catchment characteristics, the sediment records document more or less synchronous abrupt, cold departures as opposed to the smoothly decreasing trend in Northern Hemisphere summer insolation. Although all lake records document a decline in summer temperature through the Holocene consistent with the regular decline in summer insolation, the onset of significant summer cooling occurs ∼5 ka at high-elevation interior sites but is variably later at sites closer to the coast, suggesting that proximity to the sea may modulate the impact from decreasing summer insolation. The timing of glacier inception during the mid Holocene is determined by the descent of the equilibrium line altitude (ELA), which is dominated by the evolution of summer temperature as summer insolation declined as well as changes in sea surface temperature for coastal glacial systems. The glacial response to the ELA decline is also highly dependent on the local topography. The initial ∼5 ka nucleation of Langjökull in the highlands of Iceland defines the onset of neoglaciation in Iceland. Subsequently, a stepwise expansion of both Langjökull and northeast Vatnajökull occurred between 4.5 and 4.0 ka, with a second abrupt expansion ∼3 ka. Due to its coastal setting and lower topographic threshold, the initial appearance of Drangajökull in the NW of Iceland was delayed until ∼2.3 ka. All lake records reflect abrupt summer temperature and catchment disturbance at ∼4.5 ka, statistically indistinguishable from the global 4.2 ka event, and a second widespread abrupt disturbance at 3.0 ka, similar to the stepwise expansion of Langjökull and northeast Vatnajökull. Both are intervals characterized by large explosive volcanism and tephra distribution in Iceland resulting in intensified local soil erosion. The most widespread increase in glacier advance, landscape instability, and soil erosion occurred shortly after 2 ka, likely due to a complex combination of increased impact from volcanic tephra deposition, cooling climate, and increased sea ice off the coast of Iceland. All lake records indicate a strong decline in temperature ∼1.5 ka, which culminated during the Little Ice Age (1250–1850 CE) when the glaciers reached their maximum Holocene dimensions.This work was supported primarily by the Icelandic Center for Research through grants awarded to Áslaug Geirsdóttir and Gifford H. Miller (no. 130775051 and Grant of Excellence no. 141573052) and several grants awarded to Áslaug Geirsdóttir from the UI Research Fund. We thank Sædís Ólafsdóttir, Celene Blair, Sydney Gunnarson, Sarah Crump, Thorsteinn Jónsson, and Sveinbjörn Steinthorsson, who all contributed to this work by taking part in field work, laboratory analyses, and/or discussion. Thorough and constructive reviews from two anonymous reviewers have substantially improved the paper.Peer Reviewe
Diagnostic importance of pulmonary interleukin-1beta and interleukin-8 in ventilator-associated pneumonia.
BACKGROUND: Ventilator-associated pneumonia (VAP) is the most commonly fatal nosocomial infection. Clinical diagnosis of VAP remains notoriously inaccurate. The hypothesis was tested that significantly augmented inflammatory markers distinguish VAP from conditions closely mimicking VAP. METHODS: A prospective, observational cohort study was carried out in two university hospital intensive care units recruiting 73 patients with clinically suspected VAP, and a semi-urban primary care practice recruiting a reference group of 21 age- and sex-matched volunteers. Growth of pathogens at >10(4) colony-forming units (cfu)/ml of bronchoalveolar lavage fluid (BALF) distinguished VAP from "non-VAP". Inflammatory mediators were quantified in BALF and serum. Mediators showing significant differences between patients with and without VAP were analysed for diagnostic utility by receiver operator characteristic (ROC) curves. RESULTS: Seventy-two patients had recoverable lavage-24% had VAP. BALF interleukin-1beta (IL-1beta), IL-8, granulocyte colony-stimulating factor and macrophage inflammatory protein-1alpha were significantly higher in the VAP group (all p<0.005). Using a cut-off of 10 pg/ml, BALF IL-1beta generated negative likelihood ratios for VAP of 0.09. In patients with BALF IL-1beta <10 pg/ml the post-test probability of VAP was 2.8%. Using a cut-off value for IL-8 of 2 ng/ml, the positive likelihood ratio was 5.03. There was no difference in cytokine levels between patients with sterile BALF and those with growth of <10(4) cfu/ml. CONCLUSIONS: BALF IL-1beta and IL-8 are amongst the strongest markers yet identified for accurately demarcating VAP within the larger population of patients with suspected VAP. These findings have potential implications for reduction in unnecessary antibiotic use but require further validation in larger populations
'To live and die [for] Dixie': Irish civilians and the Confederate States of America
Around 20,000 Irishmen served in the Confederate army in the Civil War. As a result, they left behind, in various Southern towns and cities, large numbers of friends, family, and community leaders. As with native-born Confederates, Irish civilian support was crucial to Irish participation in the Confederate military effort. Also, Irish civilians served in various supporting roles: in factories and hospitals, on railroads and diplomatic missions, and as boosters for the cause. They also, however, suffered in bombardments, sieges, and the blockade. Usually poorer than their native neighbours, they could not afford to become 'refugees' and move away from the centres of conflict. This essay, based on research from manuscript collections, contemporary newspapers, British Consular records, and Federal military records, will examine the role of Irish civilians in the Confederacy, and assess the role this activity had on their integration into Southern communities. It will also look at Irish civilians in the defeat of the Confederacy, particularly when they came under Union occupation. Initial research shows that Irish civilians were not as upset as other whites in the South about Union victory. They welcomed a return to normalcy, and often 'collaborated' with Union authorities. Also, Irish desertion rates in the Confederate army were particularly high, and I will attempt to gauge whether Irish civilians played a role in this. All of the research in this paper will thus be put in the context of the Drew Gilpin Faust/Gary Gallagher debate on the influence of the Confederate homefront on military performance. By studying the Irish civilian experience one can assess how strong the Confederate national experiment was. Was it a nation without a nationalism
The Impact of Climate Change on Virginia\u27s Coastal Areas
As part of HJ47/SJ47 (2020), the Virginia General Assembly directed the Joint Commission on Technology and Science (JCOTS) to study the “safety, quality of life, and economic consequences of weather and climate-related events on coastal areas in Virginia.” In pursuit of this goal, the commission was to “accept any scientific and technical assistance provided by the nonpartisan, volunteer Virginia Academy of Science, Engineering, and Medicine (VASEM). VASEM convened an expert study board with representation from the Office of the Governor, planning district commissions in coastal Virginia, The Port of Virginia, the Virginia Economic Development Partnership, state universities, private industry, and law firms. In producing the report, the board followed methods similar to those used by the National Academies of Science, Engineering, and Medicine by convening an expert committee tasked with studying and reporting on the topic. As a result, the report represents the views and perspectives of the study board members but was not submitted for public review or comment.
This report is the product of those efforts. It finds that climate change will have an increasingly disruptive effect on people living in Virginia’s coastal areas during the 21st century — and that these disruptions will have repercussions across the Commonwealth. It includes an explanation of the physical forces driving climate change, an analysis of the current and projected effects of climate change on the Commonwealth, perspectives that legislators might consider as they face these challenges, and recommendations that could help Virginia implement more productive and effective strategies to address them
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