Discovery and cross-amplification of microsatellite polymorphisms in asterinid sea stars

Variation in tandem repeats of two- to six-base nucleotide motifs (microsatellites) can be used to obtain inexpensive and highly informative multi-locus data on population genetics.We developed and tested a large set of cross-amplifiable sea star (Asterinidae) microsatellite markers from a mixed pool of genomic DNA from eight species. We describe cloned sequences, primers, and PCR conditions, and characterize population-level variation for some species and markers. A few clones containing microsatellites showed considerable similarity to sequences (including genes of known function) in other sea stars and in sea urchins (from the Strongylocentrotus purpuratus complete genome). The pooled genomic DNA method was an efficient way to sample microsatellites from many species: we cloned 2-10 microsatellites from each of eight species, and most could be cross-amplified in 1-7 other species. At 12 loci in two species, we found 1-10 alleles per microsatellite, with a broad range of inbreeding coefficients. Measures of polymorphism were negatively correlated with the extent of cross-amplification.     

Cy5 labeled antimicrobial peptides for enhanced detection of Escherichia coli O157:H7

Fluorescently labeled antimicrobial peptides were evaluated as a potential replacement of labeled antibodies in a sandwich assay for the detection of Escherichia coli O157:H7. Antimicrobial peptides naturally bind to the lipopolysaccharide component of bacterial cell walls as part of their mode of action. Because of their small size relative to antibodies peptides can bind to cell surfaces with greater density, thereby increasing the optical signal and improving sensitivity. This method combines the specificity of a capture antibody with the increased sensitivity provided by using a labeled peptide as a detection molecule. The antimicrobial peptides cecropin P1, SMAP29, and PGQ were labeled with the fluorescent dye Cy5 via maleimide linker chemistry. Preliminary screening using a whole-cell solution binding assay revealed that Cy5 cecropin P1 enhanced the detection of E. coli O157:H7 relative to a Cy5 labeled anti-E. coli O157:H7 antibody 10-fold. Detection sensitivity of antibody and peptide were also compared with a prototype immuno-magnetic bead biosensor. Detection using Cy5 cecropin P1 resulted in a 10-fold improvement in sensitivity. Correlation of peptide antimicrobial activity with detection of E. coli O157:H7 indicated that activity was not predictive of the sensitivity of the fluorescent assay.     

Expression of Umbelopsis ramanniana DGAT2A in seed increases oil in soybean

Oilseeds are the main source of lipids used in both food and biofuels. The growing demand for vegetable oil has focused research toward increasing the amount of this valuable component in oilseed crops. Globally, soybean (Glycine max) is one of the most important oilseed crops grown, contributing about 30% of the vegetable oil used for food, feed, and industrial applications. Breeding efforts in soy have shown that multiple loci contribute to the final content of oil and protein stored in seeds. Genetically, the levels of these two storage products appear to be inversely correlated with an increase in oil coming at the expense of protein and vice versa. One way to overcome the linkage between oil and protein is to introduce a transgene that can specifically modulate one pathway without disrupting the other. We describe the first, to our knowledge, transgenic soy crop with increased oil that shows no major impact on protein content or yield. This was achieved by expressing a codon-optimized version of a diacylglycerol acyltransferase 2A from the soil fungus Umbelopsis (formerly Mortierella) ramanniana in soybean seed during development, resulting in an absolute increase in oil of 1.5% (by weight) in the mature seed.     

Effects of Tylosin Use on Erythromycin Resistance in Enterococci Isolated from Swine

The effect of tylosin on erythromycin-resistant enterococci was examined on three farms; farm A used tylosin for growth promotion, farm B used tylosin for treatment of disease, and farm C did not use tylosin for either growth promotion or disease treatment. A total of 1,187 enterococci were isolated from gestation, farrowing, suckling, nursery, and finishing swine from the farms. From a subset of those isolates (n = 662), 59% (124 out of 208), 28% (80 out of 281), and 2% (4 out of 170) were resistant to erythromycin (MIC ≥ 8 μg/ml) from farms A, B, and C, respectively. PCR analysis and Southern blotting revealed that 95% (65 out of 68) of isolates chosen from all three farms for further study were positive for ermB, but all were negative for ermA and ermC. By using Southern blotting, ermB was localized to the chromosome in 56 of the isolates while 9 isolates from farms A and B contained ermB on two similar-sized plasmid bands (12 to 16 kb). Pulsed-field gel electrophoresis revealed that the isolates were genetically diverse and represented a heterogeneous population of enterococci. This study suggests that although there was resistance to a greater number of enterococcal isolates on a farm where tylosin was used as a growth promotant, resistant enterococci also existed on a farm where no antimicrobial agents were used.     

Effects of calcium on the permeability of isolated adult rat heart cells to sodium

The permeability of rat heart myocytes to Na increases when extracellular Ca (Ca₀) is decreased. This increased permeability is reflected in elevated $\text{Na}\text{K}$ ratios in nonenergized myocytes and in increased ouabain-sensitive lactate production in anaerobic myocytes supplemented with glucose. Myocytes treated with ethylene glycol bis(β-aminoethyl ether)N,N′-tetraacetic acid (1 mm) maintain low $\text{Na}\text{K}$ ratios, but expend considerable glycolytic ATP in ouabain-sensitive cation cycling. The data suggest that Ca₀ bound to the sarcolemma can restrict transmembrane movement of Na via pathways that are not yet defined. The lack of significant net accumulation of Ca argues against the explanation that Ca₀ maintains low internal Na levels as a result of NaCa exchange. Both the increased uptake of Na and increased utilization of ATP in the absence of Ca₀ may be relevant to the phenomenon of “Ca-paradox” in situ.     

Efficacy and safety of cognitive enhancers for patients with mild cognitive impairment: a systematic review and meta-analysis

Background:

Cognitive enhancers, including cholinesterase inhibitors and memantine, are used to treat dementia, but their effectiveness for mild cognitive impairment is unclear. We conducted a systematic review to examine the efficacy and safety of cognitive enhancers for mild cognitive impairment.

Methods:

Our eligibility criteria were studies of the effects of donepezil, rivastigmine, galantamine or memantine on mild cognitive impairment reporting cognition, function, behaviour, global status, and mortality or harms. We identified relevant material by searching electronic databases (e.g., MEDLINE, Embase), the references of included studies, trial registries and conference proceedings, and by contacting experts. Two reviewers independently screened the results of the literature search, abstracted data and appraised risk of bias using the Cochrane risk-of-bias tool.

Results:

We screened 15 554 titles and abstracts and 1384 full-text articles. Eight randomized clinical trials and 3 companion reports met our inclusion criteria. We found no significant effects of cognitive enhancers on cognition (Mini–Mental State Examination: 3 randomized clinical trials [RCTs], mean difference [MD] 0.14, 95% confidence interval [CI] −0.22 to 0.50; Alzheimer’s Disease Assessment Scale — cognition subscale: 3 RCTs, standardized MD −0.07, 95% CI−0.16 to 0.01]) or function (Alzheimer’s Disease Cooperative Study activities of daily living inventory: 2 RCTs, MD 0.30, 95% CI −0.26 to 0.86). Cognitive enhancers were associated with higher risks of nausea, diarrhea and vomiting than placebo.

Interpretation:

Cognitive enhancers did not improve cognition or function among patients with mild cognitive impairment and were associated with a greater risk of gastrointestinal harms. Our findings do not support the use of cognitive enhancers for mild cognitive impairment. Older adults experiencing memory and cognition deficits without substantial limitations in activities of daily living may be given a diagnosis of mild cognitive impairment. ¹ These patients often present with subjective memory loss, impairment of cognitive function and no change in their basic daily functioning. Mild cognitive impairment has recently been recognized as a distinct condition, with a prevalence that ranges from 3% to 42% and increases with age. ² Because of the growing proportion of older adults worldwide, the prevalence of this condition will only increase in the future. ³ Each year, 3%–17% of people with mild cognitive impairment experience progression to dementia, ^{4 – 6} a rate that increases to between 11% and 33% by 2 years after the initial diagnosis. ⁷ More than 4.6 million new cases of dementia are diagnosed each year, ³ and efforts to reduce this public health burden are essential. Strategies to delay the progression of mild cognitive impairment are being sought to meet this challenge. One strategy that has been hypothesized to delay the progression from mild cognitive impairment to dementia is the use of cognitive enhancers, agents that are often used to treat dementia. These medications include cholinesterase inhibitors (e.g., donepezil, rivastigmine and galantamine) and the N -methyl- d -aspartic acid receptor antagonist memantine. ⁸ Donepezil, rivastigmine and galantamine increase the concentration of acetylcholine at neurotransmitter sites, ⁹ enhancing the brain’s cholinergic function. Galantamine also influences activity at nicotinic receptors, ⁹ whereas memantine modulates the neurotransmitter glutamate. ⁹ In many countries, cognitive enhancers are not widely available for patients with mild cognitive impairment. However, in some countries, including Canada, these drugs can be obtained through special authorization, ¹⁰ and patients and their families are increasingly requesting their use. Although a Cochrane review on this topic exists, ¹¹ it does not provide information on the use of memantine for mild cognitive impairment or provide data on function or global status, nor does it distinguish between overall harms and treatment-related harms. We sought to examine the efficacy and safety of cognitive enhancers for mild cognitive impairment.     

Ecological Analysis of Early Adolescents' Stress Responses to 9/11 in the Washington,DC, Area

This study uses an ecological perspective to explore the unique associations of maternal personal characteristics, parenting behaviors, and adolescents' own characteristics to posttraumatic distress and symptoms of arousal, avoidance, and intrusions, in 97 early adolescents and mothers from the Washington, DC, area to the events of September 11, 2001. Maternal characteristics and/or adolescents' perceptions of parenting behaviors were uniquely related to adolescents' responses, controlling for adolescents' own characteristics. Maternal responses and parenting behaviors play key roles in adolescents' continuing responses to the traumatic events of September 11.     

Discovery and synthesis of novel benzofurazan derivatives as inhibitors of influenza A virus

The identification of a novel hit compound inhibitor of the protein–protein interaction between the influenza RNA-polymerase PA and PB1 subunits has been accomplished by means of high-throughput screening. A small family of structurally related molecules has been synthesized and biologically evaluated with most of the compounds showing micromolar potency of inhibition against viral replication.