528 research outputs found
Acute hypocalcemia and metabolic alkalosis in children on cation-exchange resin therapy
Background. Sodium polystyrene sulfonate (SPS) is a chelating agent used for the treatment of hyperkalemia. SPS has a wide range of exchange capacity requiring close monitoring of serum electrolytes. We observed two patients who developed acute hypocalcemia and increased metabolic alkalosis after initiating SPS therapy. We report these cases to draw attention to the potential risk of this medication in pediatric patients. Case Diagnosis/Treatment. Two children with chronic kidney disease on dialysis were started on SPS for hyperkalemia. Within a week after initiation of the medication, both patients developed hypocalcemia on routine labs without overt clinical manifestations. The hypocalcemia was rapidly corrected with oral supplementation and discontinuation of SPS. Conclusions. Severe hypocalcemia can develop after SPS therapy. The metabolic alkalosis in these patients associated with the hypocalcemia put them at increased risk for complications. Hence, careful attention must be paid to the state of calcium metabolism in all patients receiving SPS. Often calcium supplementation is required to maintain normal calcium levels
Competitiveness of Brazilian Sugarcane Ethanol Compared to US Corn Ethanol
Corn ethanol produced in the US and sugarcane ethanol produced in Brazil are the world’s leading sources of biofuel. Current US biofuel policies create both incentives and constraints for the import of ethanol from Brazil, and together with the competitiveness and greenhouse gas intensity of sugarcane ethanol compared to corn ethanol will determine the extent of these imports. This study analyzes the supply-side determinants of this competitiveness and compares the greenhouse gas intensity of corn ethanol and sugarcane ethanol delivered to US ports. We find that while the cost of sugarcane ethanol production in Brazil is lower than that of corn ethanol in the US, the inclusion of transportation costs for the former and co-product credits for the latter changes their relative competitiveness. We also find that the relative cost of ethanol in the US and Brazil is highly sensitive to the prevailing exchange rate and prices of feedstocks. At an exchange rate of US2.15 the cost of corn ethanol is 15% lower than the delivered cost of sugarcane ethanol at a US port. Sugarcane ethanol has lower GHG emissions than corn ethanol but a price of over $113 per ton of CO2 is needed to affect competitiveness.economic competitiveness, renewable fuel standard, ethanol trade policy, Agribusiness, Agricultural and Food Policy,
Feasibility Testing of the Alert for AFib Intervention.
Improving early detection and treatment of atrial fibrillation (AF) is critical because untreated AF is a major contributor to stroke and heart failure. We sought to generate knowledge about the feasibility of conducting a randomized controlled trial to test the effect of the Alert for AFib intervention on knowledge, attitudes, and beliefs about treatment-seeking for signs and symptoms of AF. Adults ≥65 years old (96% White) at risk for developing AF were randomized to receive the Alert for AFib intervention ( n = 40) or an attention control session ( n = 40). Feasibility goals for recruitment, participant retention, adherence, perceived satisfaction and burden, and intervention fidelity were met. From baseline to study completion, knowledge ( p = .005) and attitudes ( p < .001) about treatment-seeking improved more in the intervention group compared with the control group. Results support testing the effectiveness of the Alert for AFib intervention in a large trial
Insertion of a Bulky Rhodium Complex into a DNA Cytosine−Cytosine Mismatch: An NMR Solution Study
The bulky octahedral complex Rh(bpy)_2chrysi^(3+) (chrysi = 5,6-chrysenequinonediimine) binds single-base mismatches in a DNA duplex with micromolar binding affinities and high selectivity. Here we present an NMR solution study to characterize the binding mode of this bulky metal complex with its target CC mismatch in the oligonucleotide duplex (5‘-CGGACTCCG-3‘)_2. Both NOESY and COSY studies indicate that Rh(bpy)_2chrysi^(3+) inserts deeply in the DNA at the mismatch site via the minor groove and with ejection of both destabilized cytosines into the opposite major groove. The insertion only minimally distorts the conformation of the oligonucleotide local to the binding site. Both flanking, well-matched base pairs remain tightly hydrogen-bonded to each other, and 2D DQF-COSY experiments indicate that all sugars maintain their original C_2‘-endo conformation. Remarkably, ^(31)P NMR reveals that opening of the phosphate angles from a B_I to a B_(II) conformation is sufficient for insertion of the bulky metal complex. These results corroborate those obtained crystallographically and, importantly, provide structural evidence for this specific insertion mode in solution
Magic squares of Lie algebras.
SIGLEAvailable from British Library Document Supply Centre-DSC:DXN038665 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Seed Collection and Germination Strategies for Common Wetland and Coastal Sage Scrub Species in Southern California
There is a need for a consolidated source of information on native vegetation seed collection and germination strategies in southern California. Published literature on these methods is often experimental, species-specific, and widely scattered throughout online and print media. Planting and restoration strategies may need to be site-specific; however, similar methodological approaches are often utilized allowing for the development of general strategies for seed collection, storage, and germination methods. A better understanding of species-specific seed attributes and growth processes will help restoration ecologists collect high-quality, viable seed, thereby increasing the potential success of the restored vegetation community by reducing plant mortality, project costs, and effort. This paper synthesizes seed collection and germination strategies for native vegetation common to southern California estuarine wetland, coastal dune, and coastal sage scrub systems
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Factors influencing the life history of spring chinook salmon (Oncorhynchus tshawytscha) spawning in the Columbia River watershed from 1960 to 1977
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Prevalence of iron deficiency in 62,685 women of seven race/ethnicity groups: The HEIRS Study.
BackgroundFew cross-sectional studies report iron deficiency (ID) prevalence in women of different race/ethnicity and ages in US or Canada.Materials and methodsWe evaluated screening observations on women who participated between 2001-2003 in a cross-sectional, primary care-based sample of adults ages ≥25 y whose observations were complete: race/ethnicity; age; transferrin saturation; serum ferritin; and HFE p.C282Y and p.H63D alleles. We defined ID using a stringent criterion: combined transferrin saturation <10% and serum ferritin <33.7 pmol/L (<15 μg/L). We compared ID prevalence in women of different race/ethnicity subgrouped by age and determined associations of p.C282Y and p.H63D to ID overall, and to ID in women ages 25-44 y with or without self-reported pregnancy.ResultsThese 62,685 women included 27,079 whites, 17,272 blacks, 8,566 Hispanics, 7,615 Asians, 449 Pacific Islanders, 441 Native Americans, and 1,263 participants of other race/ethnicity. Proportions of women with ID were higher in Hispanics and blacks than whites and Asians. Prevalence of ID was significantly greater in women ages 25-54 y of all race/ethnicity groups than women ages ≥55 y of corresponding race/ethnicity. In women ages ≥55 y, ID prevalence did not differ significantly across race/ethnicity. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy.ConclusionsID prevalence was greater in Hispanic and black than white and Asian women ages 25-54 y. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy
Analysis of Chlamydia pneumoniae and AD-like Pathology in the Brains of BALB/c Mice Following Direct Intra-cranial Infection
Alzheimer’s disease (AD) is an age-related progressive neurodegenerative disorder and the most common form of dementia. The pathology in the central nervous system (CNS) impairs memory and cognition, hindering the capabilities and the quality of life of the individual. This project continues studying the role of infection and Alzheimer’s disease, as previous studies in this laboratory have done, and contributes to the overall understanding of the possible causes of this disease. In this study, BALB/c mice were infected, via direct intracranial injection, with a respiratory isolate (AR-39) of Chlamydia pneumoniae. Their brains were analyzed at 7 and 14 days post-infection, via immunohistochemistry, for the presence of C. pneumoniae, amyloid deposits and activated glial cells. The goal of this project was to measure the location and degree of C. pneumoniae burden, amyloid deposition and glial cell activation in the CNS following direct intracranial injection and to compare this data with results obtained from previous studies in this laboratory. We hypothesized that C. pneumoniae antigen and activated inflammatory cells will be observed in the infected mouse brains following direct intracranial injection and Aβ deposition will be observed in areas where inflammation occurs. C. pneumoniae, amyloid deposits and activated glial cells were detected in the brains following direct intracranial infection with C. pneumoniae. In infected mice there was an approximate 3.5-fold increase of C. pneumoniae antigen burden compared to uninfected mice at day 7 and there was an approximate 5.5-fold increase of C. pneumoniae antigen burden compared to uninfected mice at day 14. The burden of C. pneumoniae antigen, in the infected mice, increased 1.009-fold (no change) from day 7 to day 14 post-infection. The amyloid burden in infected mice increased approximately 3-fold compared to uninfected mice at day 7 and increased greater than10-fold compared to uninfected mice at day 14. The burden of amyloid, in the infected mice, increased 7-fold from day 7 to 14. From 7 to 14 days post-infection the C. pneumoniae and amyloid deposits located near the injection site spread distally from this location to other regions of the brain. Global activation of glia was observed in the CNS of infected mice at both 7 and 14 days post-infection. This data confirms that C. pneumoniae is capable of establishing an infection in the CNS. Although deposits were observed, the lack of a substantial amount of amyloid deposits suggested that the generation of deposits may require longer than 14 days following C. pneumoniae infection. As early as 7 days post-infection, inflammation is observed in response to the presence of C. pneumoniae and/or soluble amyloid in the CNS and the contribution of both infection with C. pneumoniae and the presence of soluble amyloid elicit the inflammatory response that presumably precedes and contributes to amyloid depositionhttps://digitalcommons.pcom.edu/posters/1003/thumbnail.jp
Mutants of the Base Excision Repair Glycosylase, Endonuclease III: DNA Charge Transport as a First Step in Lesion Detection
Endonuclease III (EndoIII) is a base excision repair glycosylase that targets damaged pyrimidines and contains a [4Fe-4S] cluster. We have proposed a model where BER proteins that contain redox-active [4Fe-4S] clusters utilize DNA charge transport (CT) as a first step in the detection of DNA lesions. Here, several mutants of EndoIII were prepared to probe their efficiency of DNA/protein charge transport. Cyclic voltammetry experiments on DNA-modified electrodes show that aromatic residues F30, Y55, Y75, and Y82 help mediate charge transport between DNA and the [4Fe-4S] cluster. On the basis of circular dichroism studies to measure protein stability, mutations at residues W178 and Y185 are found to destabilize the protein; these residues may function to protect the [4Fe-4S] cluster. Atomic force microscopy studies furthermore reveal a correlation in the ability of mutants to carry out protein/DNA CT and their ability to relocalize onto DNA strands containing a single base mismatch; EndoIII mutants that are defective in carrying out DNA/protein CT do not redistribute onto mismatch-containing strands, consistent with our model. These results demonstrate a link between the ability of the repair protein to carry out DNA CT and its ability to relocalize near lesions, thus pointing to DNA CT as a key first step in the detection of base damage in the genome
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