Short-term Air Pollution Levels and Blood Pressure in Older Women.

BACKGROUND: Evidence of associations between daily variation in air pollution and blood pressure (BP) is varied and few prior longitudinal studies adjusted for calendar time. METHODS: We studied 143,658 postmenopausal women 50 to 79 years of age from the Women's Health Initiative (1993-2005). We estimated daily atmospheric particulate matter (PM) (in three size fractions: PM2.5, PM2.5-10, and PM10) and nitrogen dioxide (NO2) concentrations at participants' residential addresses using validated lognormal kriging models. We used linear mixed-effects models to estimate the association between air pollution concentrations and repeated measures of systolic and diastolic BP (SBP, DBP) adjusting for confounders and calendar time. RESULTS: Short-term PM2.5 and NO2 were each positively associated with DBP {0.10 mmHg [95% confidence interval (CI): 0.04, 0.15]; 0.13 mmHg (95% CI: 0.09, 0.18), respectively} for interquartile range changes in lag 3-5 day PM2.5 and NO2. Short-term NO2 was negatively associated with SBP [-0.21 mmHg (95%CI: -0.30, -0.13)]. In two-pollutant models, the NO2-DBP association was slightly stronger, but for PM2.5 was attenuated to null, compared with single-pollutant models. Associations between short-term NO2 and DBP were more pronounced among those with higher body mass index, lower neighborhood socioeconomic position, and diabetes. When long-term (annual) and lag 3-5 day PM2.5 were in the same model, associations with long-term PM2.5 were stronger than for lag 3-5 day. CONCLUSIONS: We observed that short-term PM2.5 and NO2 levels were associated with increased DBP, although two-pollutant model results suggest NO2 was more likely responsible for observed associations. Long-term PM2.5 effects were larger than short-term.

Novel placental structure in the Mexican gerrhonotine lizard, Mesaspis viridiflava (Lacertilia; Anguidae).

The evolution of viviparity alters the physical relationship between mothers and offspring and the prevalence of viviparity among squamate reptiles presents an opportunity to uncover patterns in the evolution of placental structure. Understanding the breadth of this diversity is limited because studies of placental structure and function have emphasized a limited number of lineages. We studied placental ontogeny using light microscopy for an embryological series of the Mexican gerrhonotine lizard, Mesaspis viridiflava. This species develops an elaborate yolk sac placenta, an omphaloplacenta, which receives vascular support arising in a structure known only from other gerrhonotine lizards. A prominent feature of the omphaloplacenta is a zone of uterine and embryonic epithelial cell hyperplasia located at the upper shoulder of the yolk mass, often extending above the yolk mass. The omphaloplacenta covers more than one-half of the surface area of maternal-embryonic contact. The chorioallantoic placenta has a more restricted distribution because the allantois remains in the embryonic hemisphere of the egg throughout development and lies internal to the vascular support for the omphaloplacenta in areas where they overlap. The structural profile of the chorioallantoic placenta indicates a potential for respiratory exchange and/or hemotrophic nutritive transport, while that of the omphaloplacenta suggests that nutritive transfer is primarily via histotrophy. An eggshell is present in the earliest embryonic stages examined but regresses relatively early in development. Placental specializations of this species are consistent with a pattern of matrotrophic embryonic nutrition and have evolved in a unique lineage specific developmental pattern.

A Next-Generation Bioresorbable CoronaryScaffold System: From Bench toFirst Clinical Evaluation

This study sought to perform clinical and imaging assessments of the DESolveBioresorbable Coronary Scaffold (BCS).Background BCS, which is drug eluting, may have potential advantages compared with conventionalmetallic drug-eluting stents. The DESolve system, designed to provide vessel support and neointimalsuppression, combines a poly-L-lactic acid–based scaffold with the antiproliferative myolimus.Methods The DESolve First-in-Man (A NON-RANDOMIZED, CONSECUTIVE ENROLLMENT EVALUATIONOF THE DESolve MYOLIMUS ELUTING BIORESORBABLE CORONARY STENT IN THE TREATMENT OFPATIENTS WITH DE NOVO NATIVE CORONARY ARTERY LESIONS) trial was a prospective multicenterstudy enrolling 16 patients eligible for treatment. The principal safety endpoint was a composite ofcardiac death, myocardial infarction, and clinically indicated target lesion revascularization. Theprincipal imaging endpoint was in-scaffold late lumen loss (LLL) assessed by quantitative coronaryangiography (QCA) at 6 months. Intravascular ultrasound (IVUS) and optical coherence tomography(OCT) imaging was performed at baseline and 6 months; multislice computed tomography (MSCT) wasperformed at 12 months.Results Acute procedural success was achieved in 15 of 15 patients receiving a study scaffold. At12 months, there was no scaffold thrombosis and no major adverse cardiac events directly attributableto the scaffold. At 6 months, in-scaffold LLL (by QCA) was 0.19 0.19 mm; neointimal volume (by IVUS)was 7.19 3.56%, with no evidence of scaffold recoil or late malapposition. Findings were confirmedwith OCT and showed uniform, thin neointimal coverage (0.12 0.04 mm). At 12 months, MSCTdemonstrated excellent vessel patency.

Sparkle/PM7 Lanthanide Parameters for the Modeling of Complexes and Materials.

The recently published Parametric Method number 7, PM7, is the first semiempirical method to be successfully tested by modeling crystal structures and heats of formation of solids. PM7 is thus also capable of producing results of useful accuracy for materials science, and constitutes a great improvement over its predecessor, PM6. In this article, we present Sparkle Model parameters to be used with PM7 that allow the prediction of geometries of metal complexes and materials which contain lanthanide trications. Accordingly, we considered the geometries of 224 high-quality crystallographic structures of complexes for the parameterization set and 395 more for the validation of the parameterization for the whole lanthanide series, from La(III) to Lu(III). The average unsigned error for Sparkle/PM7 for the distances between the metal ion and its coordinating atoms is 0.063Å for all lanthanides, ranging from a minimum of 0.052Å for Tb(III) to 0.088Å for Ce(III), comparable to the equivalent errors in the distances predicted by PM7 for other metals. These distance deviations follow a gamma distribution within a 95% level of confidence, signifying that they appear to be random around a mean, confirming that Sparkle/PM7 is a well-tempered method. We conclude by carrying out a Sparkle/PM7 full geometry optimization of two spatial groups of the same thulium-containing metal organic framework, with unit cells accommodating 376 atoms, of which 16 are Tm(III) cations; the optimized geometries were in good agreement with the crystallographic ones. These results emphasize the capability of the use of the Sparkle Model for the prediction of geometries of compounds containing lanthanide trications within the PM7 semiempirical model, as well as the usefulness of such semiempirical calculations for materials modeling. Sparkle/PM7 is available in the software package MOPAC2012, at no cost for academics and can be obtained from http://openmopac.net.

RM1: a reparameterization of AM1 for H, C, N, O, P, S, F, Cl, Br, and I.

Twenty years ago, the landmark AM1 was introduced, and has since had an increasingly wide following among chemists due to its consistently good results and time-tested reliability--being presently available in countless computational quantum chemistry programs. However, semiempirical molecular orbital models still are of limited accuracy and need to be improved if the full potential of new linear scaling techniques, such as MOZYME and LocalSCF, is to be realized. Accordingly, in this article we present RM1 (Recife Model 1): a reparameterization of AM1. As before, the properties used in the parameterization procedure were: heats of formation, dipole moments, ionization potentials and geometric variables (bond lengths and angles). Considering that the vast majority of molecules of importance to life can be assembled by using only six elements: C, H, N, O, P, and S, and that by adding the halogens we can now build most molecules of importance to pharmaceutical research, our training set consisted of 1736 molecules, representative of organic and biochemistry, containing C, H, N, O, P, S, F, Cl, Br, and I atoms. Unlike AM1, and similar to PM3, all RM1 parameters have been optimized. For enthalpies of formation, dipole moments, ionization potentials, and interatomic distances, the average errors in RM1, for the 1736 molecules, are less than those for AM1, PM3, and PM5. Indeed, the average errors in kcal x mol(-1) of the enthalpies of formation for AM1, PM3, and PM5 are 11.15, 7.98, and 6.03, whereas for RM1 this value is 5.77. The errors, in Debye, of the dipole moments for AM1, PM3, PM5, and RM1 are, respectively, 0.37, 0.38, 0.50, and 0.34. Likewise, the respective errors for the ionization potentials, in eV, are 0.60, 0.55, 0.48, and 0.45, and the respective errors, in angstroms, for the interatomic distances are 0.036, 0.029, 0.037, and 0.027. The RM1 average error in bond angles of 6.82 degrees is only slightly higher than the AM1 figure of 5.88 degrees, and both are much smaller than the PM3 and PM5 figures of 6.98 degrees and 9.83 degrees, respectively. Moreover, a known error in PM3 nitrogen charges is corrected in RM1. Therefore, RM1 represents an improvement over AM1 and its similar successor PM3, and is probably very competitive with PM5, which is a somewhat different model, and not fully disclosed. RM1 possesses the same analytical construct and the same number of parameters for each atom as AM1, and, therefore, can be easily implemented in any software that already has AM1, not requiring any change in any line of code, with the sole exception of the values of the parameters themselves.

Characterisation of a Leishmania mexicana knockout lacking guanosine diphosphate-mannose pyrophosphorylase.

In eukaryotes, the enzyme GDP-mannose pyrophosphorylase (GDP-MP) is essential for the formation of GDP-mannose, the donor of activated mannose for all glycosylation reactions. Unlike other eukaryotes, where deletion of GDP-mannose pyrophosphorylase is lethal, deletion of this gene in Leishmania mexicana has no effect on viability, but leads to the generation of avirulent parasites. In this study, we show that the null mutants have a perturbed morphology and cytokinesis, retarded growth and increased adherence to the substratum where they form large colonies. The null mutants attach avidly to mouse macrophages, but unlike the wild type organisms, they do not bind to the complement receptor 3 and are slow to induce phagocytosis. Once internalised, they localise to the phagolysosome, but in contrast to wild type organisms which transform into the intracellular amastigote and establish in the macrophage, they are cleared by 24 h in culture and by 5 h in vivo. The null mutants are hypersensitive to human but not mouse complement and to temperature and acidic pH. Surprisingly, in view of the lack of several known host-protective antigens, injection of the mutant parasites into BALB/c mice confers significant and long lasting protection against infection, suggesting that these temperature sensitive mutants are an attractive candidate for a live attenuated vaccine.

Placentation in the Mexican lizard Sceloporus mucronatus (Squamata: Phrynosomatidae).

We used light microscopy to study placental structure of the lizard Sceloporus mucronatus throughout 6 months of embryonic development. Three stages of placental development could be assigned to embryos based on the arrangement of the extraembryonic membranes. A highly vascular choriovitelline placenta was present in the embryonic hemisphere and a nonvascular bilaminar omphalopleure covered most of the abembryonic hemisphere of the egg during embryonic Stages 10-28. A chorioallantoic placenta replaced the choriovitelline placenta by embryonic Stage 29 and an omphaloplacenta covered the abembryonic hemisphere at this stage. The combination of these two placental types occurred in Stage 29-36 embryos. The final stage of placentation, embryonic Stages 37-40, was characterized by an omphalallantoic placenta in the abembryonic hemisphere and a chorioallantoic placenta in the embryonic hemisphere of the egg. The choriovitelline and chorioallantoic placentae are well vascularized, with closely apposed maternal and embryonic blood vessels. These structures are the most likely sites of respiratory exchange. In contrast, the omphaloplacenta and omphalallantoic placentae contain cuboidal or columnar epithelia and these structures may function in histotrophic exchange. Placentation of S. mucronatus is similar to that of predominantly lecithotrophic species in other squamate lineages suggesting that the evolution of this placental morphology is a response to similar factors and is independent of phylogeny.

Properties of GDP-mannose pyrophosphorylase, a critical enzyme and drug target in Leishmania mexicana.

Leishmania parasites synthesize a range of mannose-containing glycoconjugates thought to be essential for virulence in the mammalian host and sandfly vector. A prerequisite for the synthesis of these molecules is the availability of the activated mannose donor, GDP-Man, the product of the catalysis of mannose-1-phosphate and GTP by GDP-mannose pyrophosphorylase (GDP-MP). In contrast to the lethal phenotype in fungi, the deletion of the gene in Leishmania mexicana did not affect parasite viability but led to a total loss of virulence, making GDP-MP an ideal target for anti-Leishmania drug development. We show by immunofluorescence and subcellular fractionation that GDP-MP is a cytoplasmic protein, and we describe a colorimetric activity assay suitable for the high throughput screening of small molecule inhibitors. We expressed recombinant GDP-MP as a fusion with maltose-binding protein and separated the enzyme from maltose-binding protein by thrombin cleavage, ion-exchange, and size exclusion chromatography. Size exclusion chromatography and analytical ultracentrifugation studies demonstrate that GDP-MP self-associates to form an enzymatically active and stable hexamer. However, sedimentation studies show that the GDP-MP hexamer dissociates to trimers and monomers in a time-dependent manner, at low protein concentrations, at low ionic strength, and at alkaline pH. Circular dichroism spectroscopy reveals that GDP-MP is comprised of mixed alpha/beta structure, similar to its closest related homologue, N-acetyl-glucoseamine-1-phosphate uridyltransferase (Glmu) from Streptococcus pneumoniae. Our studies provide insight into the structure of a novel target for the development of anti-Leishmania drugs.