Human serological assays designed to detect brucellosis will miss infections caused by Brucella canis, and low levels of periodic bacteremia limit diagnosis by blood culture. Recent B. canis ...outbreaks in dogs and concomitant illnesses in caretakers suggest that unapparent human infections may be occurring. With more than a quarter of a million persons in occupations involving dogs, and nearly 80 million dog owners in the United States, this pathogen is an under‐recognized human health threat. To investigate occupational exposure to B. canis, we adapted a commercial canine serological assay and present the first controlled seroepidemiological study of human B. canis infections in recent years. 306 adults with occupational exposure to dogs and 101 non‐matched, non‐canine‐exposed subjects were enrolled. Antibodies were detected using the canine D‐Tec® CB rapid slide agglutination test (RSAT) kit with a secondary 2‐mercaptoethanol (ME)‐RSAT. Results were validated on a blinded subset of sera with an additional RSAT and indirect enzyme‐linked immunoassay at the National Administration of Laboratories and Health Institutes (ANLIS) in Argentina. Seroprevalence ranged from 10.8% (RSAT) to 3.6% (ME‐RSAT) among canine‐exposed subjects. Kennel employees were more likely to test RSAT seropositive compared with other canine exposures (OR = 2.7; 95% CI, 1.3–5.8); however, low seroprevalence limited meaningful occupational risk factor analyses. Two seropositive participants reported experiencing symptoms consistent with brucellosis and having exposure to B. canis‐infected dogs; however, temporality of symptom onset with reported exposure could not be determined. D‐Tec® CB results had substantial agreement with ANLIS assays (Cohen's kappa = 0.60–0.68). These data add to a growing body of literature suggesting that people occupationally exposed to dogs may be at risk of unapparent B. canis infection. It seems prudent to consider B. canis as an occupational public health concern and encourage the development of serological assays to detect human B. canis infections.
The heterodimeric Elongin BC complex has been shown to interact in vitro and in cells with a conserved BC-box motif found in an increasing number of proteins including RNA polymerase II elongation ...factor Elongin A, suppressor of cytokine signaling (SOCS)-box proteins, and the von Hippel-Lindau tumor suppressor protein. Recently, the Elongin BC complex was found to function as an adaptor that links these BC-box proteins to a module composed of Cullin family members Cul2 or Cul5 and RING-H2 finger protein Rbx1 to reconstitute a family of E3 ubiquitin ligases that activate ubiquitylation by the E2 ubiquitin-conjugating enzyme Ubc5. As part of our effort to understand the functions of Elongin BC-based ubiquitin ligases, we exploited a modified yeast two-hybrid screen to identify a mammalian BC-box protein similar in sequence to Saccharomyces cerevisiae Mediator subunit Med8p. In this report we demonstrate (i) that mammalian MED8 is a subunit of the mammalian Mediator complex and (ii) that MED8 can assemble with Elongins B and C, Cul2, and Rbx1 to reconstitute a ubiquitin ligase. Taken together, our findings are consistent with the model that MED8 could function to recruit ubiquitin ligase activity directly to the RNA polymerase II transcriptional machinery.
Performance of 10- and 20-target MSE classifiers Novak, L.M.; Owirka, G.J.; Brower, W.S.
IEEE transactions on aerospace and electronic systems,
10/2000, Letnik:
36, Številka:
4
Journal Article
Recenzirano
Odprti dostop
MIT Lincoln Laboratory is responsible for developing the ATR (automatic target recognition) system for the DARPA-sponsored SAIP program; the baseline ATR system recognizes 10 GOB (ground order of ...battle) targets; the enhanced version of SAIP requires the ATR system to recognize 20 GOB targets. This paper presents ATR performance results for 10- and 20-target mean square error (MSE) classifiers using high-resolution SAR (synthetic aperture radar) imagery.
The Mediator is a multiprotein coactivator required for activation of RNA polymerase II transcription by DNA binding transactivators.
We recently identified a mammalian homologue of yeast Mediator ...subunit Med8 and partially purified a Med8-containing Mediator
complex from rat liver nuclei (Brower, C. S., Sato, S., Tomomori-Sato, C., Kamura, T., Pause, A., Stearman, R., Klausner,
R. D., Malik, S., Lane, W. S., Sorokina, I., Roeder, R. G., Conaway, J. W., and Conaway, R. C. (2002) Proc. Natl. Acad. Sci. U.âS.âA. 99, 10353â10358). Analysis of proteins present in the most highly purified Med8-containing fractions by tandem mass spectrometry
led to the identification of many known mammalian Mediator subunits, as well as four potential Mediator subunits exhibiting
sequence similarity to yeast Mediator subunits Srb5, Srb6, Med11, and Rox3. Here we present direct biochemical evidence that
these four proteins are bona fide mammalian Mediator subunits. In addition, we identify direct pairwise binding partners of these proteins among the known
mammalian Mediator subunits. Taken together, our findings identify a collection of novel mammalian Mediator subunits and shed
new light on the underlying architecture of the mammalian Mediator complex.
Design of Membrane Cascades Gunderson, S. S.; Brower, W. S.; O'Dell, J. L. ...
Separation science and technology,
01/2007, Letnik:
42, Številka:
10
Journal Article
Recenzirano
Suggestions are made for the practical implementation of membrane cascades using diafiltration for the fractionation of solute pairs. Experiments are described that demonstrate the desirability of ...replacing solvent during the course of each diafiltration, and a parallel modeling development suggests an attractive means for accomplishing this replacement. A batch process is described to achieve such separations by simple assemblies of existing equipment, and suggestions are made for designing continuous processors. Such cascades are attractive for a wide variety of solutes including native proteins, as well as commodity chemicals, and they can be applied to the resolution of enantiomers through simple modifications already described in the public literature. The same techniques can be applied to multicomponent systems using the concept of key components as has long been done in distillation.
The low inherent capital costs and high throughput rates of such membrane cascades strongly suggest that they should compete successfully against a significant number of presently used chromatographic processes, and their simplicity should make then formidable competitors to simulated moving beds as well.
Integrin-ligand interactions can be influenced by the sequence in a disulfide-bridged loop between the 8th and 9th β subunit cysteines. Previous experiments are consistent with C8–C9 loop residues ...being involved in direct ligand–integrin interactions and/or being important in heterodimer regulation. In βPS from
Drosophila melanogaster and three other dipterans, the C8–C9 loop consists of only two amino acids, and exists in two forms that arise by differential splicing of exon 4. In these species, the βPS4A isoform has an acidic residue in the first loop position (C8+1), with an alanine or proline in the corresponding position of βPS4B. Mutations in both isoforms (in combination with αPS2) can reduce cell spreading during normal growth, but function is generally restored under conditions that enhance integrin activation. Replacement of the βPS4A acidic residue with a basic lysine has relatively modest effects on integrin function. Spread cells bearing C8–C9 mutations tend to become less elongated, with reduced frequencies of actin stress fibers. The results indicate that even a minimal, two-residue C8–C9 loop contains structural information that can differentially regulate integrin activity and/or integrin signaling, and that this regulation does not rely on direct molecular interactions involving the variable C8+1 side chains.
The Drosophila PS1 and PS2 integrins are required to maintain the connection between the dorsal and ventral wing epithelia. If alphaPS subunits are inappropriately expressed during early pupariation, ...the epithelia separate, causing a wing blister. Two lines of evidence indicate that this apparent loss-of-function phenotype is not a dominant negative effect, but is due to inappropriate expression of functional integrins: wing blisters are not generated efficiently by misexpression of loss-of-function alphaPS2 subunits with mutations that inhibit ligand binding, and gain-of-function, hyperactivated mutant alphaPS2 proteins cause blistering at expression levels well below those required by wild-type proteins. A genetic screen for dominant suppressors of wing blisters generated null alleles of a gene named moleskin, which encodes the protein DIM-7. DIM-7, a Drosophila homolog of vertebrate importin-7, has recently been shown to bind the SHP-2 tyrosine phosphatase homolog Corkscrew and to be important in the nuclear translocation of activated D-ERK. Consistent with this latter finding, homozygous mutant clones of moleskin fail to grow in the wing. Genetic tests suggest that the moleskin suppression of wing blisters is not directly related to inhibition of D-ERK nuclear import. These data are discussed with respect to the possible regulation of integrin function by cytoplasmic ERK.
SUMMARY The identification and functional studies of DM domain‐containing proteins Doublesex, MAB‐3, and DMRT1 indicated that flies, nematodes, and humans share at least some of the molecular ...mechanisms of sex determination. We identified a gene, AmDM1, from the coral Acropora millepora that encodes a homologous DM domain‐containing protein. Molecular analyses show that the AmDM1 primary transcript is processed to generate four different messenger RNAs. Alternative use of two polyadenylation sites produces transcripts that vary only in the 3′ untranslated regions, whereas alternative splicing generates transcripts with and without the region coding for the DM domain. All the transcripts include a second motif, the DMA domain, which is found in a number of other proteins containing a DM domain. Hermaphroditic A. millepora differentiates sexual cells seasonally before the spring spawn, and Northern blot analysis shows that the AmDM1 transcripts are present at higher levels during sexual differentiation. The non‐DM domain‐containing messages are also present at significant levels in late embryos, but DM domain transcripts are extremely rare at this stage. These data suggest that the association of DM domain proteins and sexual determination or differentiation predates the separation of the Cnidaria from the rest of the Metazoa.
An intravenous infusion of 40 mg of recombinant tissue-type plasminogen activator (rt-PA) was given intravenously over 90 minutes to 123 patients with acute myocardial infarction (AMI) of less than 4 ...hours' duration. A coronary angiogram was recorded at the end of the infusion in 119 patients. Central assessment of the angiograms revealed a patent infarct-related artery in 78 patients (patency rate 66%, 95% confidence limits 57 to 74%). Patients with a patent infarct-related artery at the first angiogram were randomized in a double-blind manner to receive a subsequent 6-hour infusion of either 30 mg of rt-PA or placebo. All patients had received an initial bolus of 5,000 IU of heparin and then 1,000 IU/hour until a second angiogram was recorded 6 to 24 hours after the start of the second perfusion. At central assessment of the second coronary angiogram the reocclusion rate was 2 of 36 patients who received rt-PA at the second infusion and 3 of 37 patients not receiving this drug (or the 2 groups combined 7%, 95% confidence limits 2 to 15%). Three of 60 patients (5%, 95% confidence limits 1 to 14%) with patent arteries on both previous angiograms had a later occlusion as judged on the angiogram recorded at hospital discharge. No difference in late reocclusion rates between the 2 treatment groups was observed.
Butterflies (Papilionoidea) are perhaps the most charismatic insect lineage, yet phylogenetic relationships among them remain incompletely studied and controversial. This is especially true for ...skippers (Hesperiidae), one of the most species-rich and poorly studied butterfly families.
To infer a robust phylogenomic hypothesis for Hesperiidae, we sequenced nearly 400 loci using Anchored Hybrid Enrichment and sampled all tribes and more than 120 genera of skippers. Molecular datasets were analyzed using maximum-likelihood, parsimony and coalescent multi-species phylogenetic methods.
All analyses converged on a novel, robust phylogenetic hypothesis for skippers. Different optimality criteria and methodologies recovered almost identical phylogenetic trees with strong nodal support at nearly all nodes and all taxonomic levels. Our results support Coeliadinae as the sister group to the remaining skippers, the monotypic Euschemoninae as the sister group to all other subfamilies but Coeliadinae, and the monophyly of Eudaminae plus Pyrginae. Within Pyrginae, Celaenorrhinini and Tagiadini are sister groups, the Neotropical firetips, Pyrrhopygini, are sister to all other tribes but Celaenorrhinini and Tagiadini. Achlyodini is recovered as the sister group to Carcharodini, and Erynnini as sister group to Pyrgini. Within the grass skippers (Hesperiinae), there is strong support for the monophyly of Aeromachini plus remaining Hesperiinae. The giant skippers (Agathymus and Megathymus) once classified as a subfamily, are recovered as monophyletic with strong support, but are deeply nested within Hesperiinae.
Anchored Hybrid Enrichment sequencing resulted in a large amount of data that built the foundation for a new, robust evolutionary tree of skippers. The newly inferred phylogenetic tree resolves long-standing systematic issues and changes our understanding of the skipper tree of life. These resultsenhance understanding of the evolution of one of the most species-rich butterfly families.
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