Valve ultrastructure of some confusing Fragilariacease

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24545/1/0000825.pd

Complete genome sequence of microcystis aeruginosa FD4, isolated from a subtropical river in Southwest Florida

We report the first complete genome of Microcystis aeruginosa from North America. A harmful bloom that occurred in the Caloosahatchee River in 2018 led to a state of emergency declaration in Florida. Although strain FD4 was isolated from this toxic bloom, the genome did not have a microcystin biosynthetic gene cluster

The BAF chromatin remodelling complex is an epigenetic regulator of lineage specification in the early mouse embryo.

Dynamic control of gene expression is essential for the development of a totipotent zygote into an embryo with defined cell lineages. The accessibility of genes responsible for cell specification to transcriptional machinery is dependent on chromatin remodelling complexes such as the SWI\SNF (BAF) complex. However, the role of the BAF complex in early mouse development has remained unclear. Here, we demonstrate that BAF155, a major BAF complex subunit, regulates the assembly of the BAF complex in vivo and regulates lineage specification of the mouse blastocyst. We find that associations of BAF155 with other BAF complex subunits become enriched in extra-embryonic lineages just prior to implantation. This enrichment is attributed to decreased mobility of BAF155 in extra-embryonic compared with embryonic lineages. Downregulation of BAF155 leads to increased expression of the pluripotency marker Nanog and its ectopic expression in extra-embryonic lineages, whereas upregulation of BAF155 leads to the upregulation of differentiation markers. Finally, we show that the arginine methyltransferase CARM1 methylates BAF155, which differentially influences assembly of the BAF complex between the lineages and the expression of pluripotency markers. Together, our results indicate a novel role of BAF-dependent chromatin remodelling in mouse development via regulation of lineage specification.We are grateful to: W. Xu for an antibody against methylated BAF155; R. Kemler for an antibody against Troma1, A. Surani for TS cells, P. Almeida Coelho, S. Vuoristo and A. Hupalowska for technical assistance; M. Bredford for the CARM1 -/- line; D. Glover, M-E Torres-Padilla, P. P. Amaral, K. Miyamoto, A. Bruce, I. Bedzhov and J. Gurdon for helpful suggestions. This work was supported by The Wellcome Trust Senior Fellowship to MZG; M.P. is supported by the Darwin Trust of Edinburgh.This is the final version of the article. It first appeared from The Company of Biologists via https://doi.org/10.1242/dev.13196

Chemical synthesis of the organoarsenical antibiotic arsinothricin

We report two routes of chemical synthesis of arsinothricin (AST), the novel organoarsenical antibiotic. One is by condensation of the 2-chloroethyl(methyl)arsinic acid with acetamidomalonate, and the second involves reduction of the N-acetyl protected derivative of hydroxyarsinothricin (AST-OH) and subsequent methylation of a trivalent arsenic intermediate with methyl iodide. The enzyme AST N-acetyltransferase (ArsN1) was utilized to purify l-AST from racemic AST. This chemical synthesis provides a source of this novel antibiotic for future drug development

Anharmonic effects in the A15 compounds induced by sublattice distortions

We demonstrate that elastic anomalies and lattice instabilities in the the A15 compounds are describable in terms of first-principles LDA electronic structure calculations. We show that at T=0 V_3Si, V_3Ge, and Nb_3Sn are intrinsically unstable against shears with elastic moduli C_11-C_12 and C_44, and that the zone center phonons, Gamma_2 and Gamma_12, are either unstable or extremely soft. We demonstrate that sublattice relaxation (internal strain) effects are key to understanding the behavior of the A15 materials.Comment: 5 pages, RevTex, 3 postscript figures, Submitted to Phys. Rev. Lett. Apr. 23, 1997 July 7, 1997: minor corrections, final accepted versio

The Epidemiology of Lead Toxicity in Adults: Measuring Dose and Consideration of Other Methodologic Issues

We review several issues of broad relevance to the interpretation of epidemiologic evidence concerning the toxicity of lead in adults, particularly regarding cognitive function and the cardiovascular system, which are the subjects of two systematic reviews that are also part of this mini-monograph. Chief among the recent developments in methodologic advances has been the refinement of concepts and methods for measuring individual lead dose in terms of appreciating distinctions between recent versus cumulative doses and the use of biological markers to measure these parameters in epidemiologic studies of chronic disease. Attention is focused particularly on bone lead levels measured by K-shell X-ray fluorescence as a relatively new biological marker of cumulative dose that has been used in many recent epidemiologic studies to generate insights into lead’s impact on cognition and risk of hypertension, as well as the alternative method of estimating cumulative dose using available repeated measures of blood lead to calculate an individual’s cumulative blood lead index. We review the relevance and interpretation of these lead biomarkers in the context of the toxico-kinetics of lead. In addition, we also discuss methodologic challenges that arise in studies of occupationally and environmentally exposed subjects and those concerning race/ethnicity and socioeconomic status and other important covariates

Skeletal concentrations of lead, cadmium, zinc, and silver in ancient North American Pecos Indians.

Bone samples of 14 prehistoric North American Pecos Indians from circa 1400 A.D. were analyzed for lead, cadmium, zinc, and silver by graphite furnace atomic absorption spectrometry to establish the baseline levels of these elements in an ancient North American population. Measurements of outer and inner bone fractions indicate the former were contaminated postmortem for lead, zinc, and cadmium. The contamination-adjusted average (mean +/- SD) level of lead (expressed as the ratio of atomic lead to atomic calcium) in bones of the Indians was 8.4 +/- 4.4 x 10(-7)), which was similar to ratios in bones of ancient Peruvians (0.9 to 7.7 x 10(-7)) and significantly lower than ratios in bones of modern adults in England and the United States (210 to 350 x 10(-7]. The adjusted average concentrations (microgram per gram dry weight) of biologic cadmium, silver, and zinc in the Pecos Indian bones were 0.032 +/- 0.013, 0.094 +/- 0.044, and 130 +/- 66, as compared to concentrations of 1.8, 0.01 to 0.44, and 75 to 170 in the bones of modern people, respectively. Therefore, cadmium concentrations in Pecos Indian bones are also approximately 50-fold lower than those of contemporary humans. These data support earlier findings that most previously reported natural concentrations of lead in human tissues are erroneously high and indicate that natural concentrations of cadmium are also between one and two orders of magnitude lower than contemporary concentrations

Hormone replacement therapy and the risk of ovarian cancer in BRCA1 and BRCA2 mutation carriers

Abstract Objective. Hormone replacement therapy (HRT) is commonly prescribed to alleviate the climacteric symptoms of menopause. Recent findings from the Women's Health Initiative has raised questions about the routine use of HRT due to the increased observed incidence of cardiovascular disease and of breast and ovarian cancers in the treatment arm of the trial. In the general population, the association between HRT use and risk of ovarian cancer has not yet been resolved. This association has not been evaluated in BRCA1 or BRCA2 mutation carriers who face very high lifetime risks of both breast and ovarian cancers. Methods. We conducted a matched case-control study on 162 matched sets of women who carry a deleterious mutation in either the BRCA1 or BRCA2 gene. Women who had been diagnosed with ovarian cancer were matched to control subjects by mutation, year of birth, and age at menopause. Information on HRT use was derived from a questionnaire routinely administered to women who were found to be carriers of a mutation in either gene. Conditional logistic regression was used to estimate the association between HRT use and the risk of ovarian cancer, stratified by mutation status and type of HRT. Results. Compared with those who had never used HRT, the odds ratio associated with ever use of HRT was 0.93 (95% CI = 0.56 -1.56). There was no significant relationship with increasing duration of HRT use. There was a suggestion that progestinbased HRT regimens might protect against ovarian cancer (odds ratio = 0.57) but this association was not statistically significant ( P = 0.20). Conclusion. HRT use does not appear to adversely influence the risk of ovarian cancer in BRCA mutation carriers.

Computational and Serologic Analysis of Novel and Known Viruses in Species Human Adenovirus D in Which Serology and Genomics Do Not Correlate

In November of 2007 a human adenovirus (HAdV) was isolated from a bronchoalveolar lavage (BAL) sample recovered from a biopsy of an AIDS patient who presented with fever, cough, tachycardia, and expiratory wheezes. To better understand the isolated virus, the genome was sequenced and analyzed using bioinformatic and phylogenomic analysis. The results suggest that this novel virus, which is provisionally named HAdV-D59, may have been created from multiple recombination events. Specifically, the penton, hexon, and fiber genes have high nucleotide identity to HAdV-D19C, HAdV-D25, and HAdV-D56, respectively. Serological results demonstrated that HAdV-D59 has a neutralization profile that is similar yet not identical to that of HAdV-D25. Furthermore, we observed a two-fold difference between the ability of HAdV-D15 and HAdV-D25 to be neutralized by reciprocal antiserum indicating that the two hexon proteins may be more similar in epitopic conformation than previously assumed. In contrast, hexon loops 1 and 2 of HAdV-D15 and HAdV-D25 share 79.13 and 92.56 percent nucleotide identity, respectively. These data suggest that serology and genomics do not always correlate