Molecular epidemiology of Bacillus anthracis: determining the correct origin

We analyzed and compared strains of Bacillus anthracis isolated from husbandry and industrial anthrax cases in Switzerland between 1952 and 1981 with published data using multiple-locus variable-number tandem repeat analysis. Strains isolated from autochthonous cases of anthrax in cattle belong to genotype B2, together with strains from continental Europe, while human B. anthracis strains clustered with genotype A4. These strains could be traced back to outbreaks of human anthrax that occurred between 1978 and 1981 in a factory processing cashmere wool from the Indian subcontinent. We interpret the worldwide occurrence of B. anthracis strains of cluster A4 to be due to the extensive global trade of untreated cashmere wool during the last century.

End-tidal CO2 pressure: an important parameter for a correct interpretation of changes in cerebral hemodynamics and oxygenation measured with functional near infrared spectrophotometry (fNIRS)

The aim of the present study was to investigate the effects of different speech tasks (recitation of prose (PR), alliteration (AR) and hexameter (HR) verses) and a control task (mental arithmetic (MA) with voicing of the result) on endtidal CO2 (ET-CO2), cerebral hemodynamics; i.e. total hemoglobin (tHb) and tissue oxygen saturation (StO2). tHb and StO2 were measured with a frequency domain near infrared spectrophotometer (ISS Inc., USA) and ET-CO2 with a gas analyzer (Nellcor N1000). Measurements were performed in 24 adult volunteers (11 female, 13 male; age range 22 to 64 years) during task performance in a randomized order on 4 different days to avoid potential carry over effects. Statistical analysis was applied to test differences between baseline, 2 recitation and 5 recovery periods. The two brain hemispheres and 4 tasks were tested separately. Data analysis revealed that during the recitation tasks (PR, AR and HR) StO2 decreased statistically significant (p < 0.05) during PR and AR in the right prefrontal cortex (PFC) and during AR and HR in the left PFC. tHb showed a significant decrease during HR in the right PFC and during PR, AR and HR in the left PFC. During the MA task, StO2 increased significantly. A significant decrease in ET-CO2 was found during all 4 tasks with the smallest decrease during the MA task. In conclusion, we hypothesize that the observed changes in tHb and StO2 are mainly caused by an altered breathing during the tasks that led a lowering of the CO2 content in the blood provoked a cerebral CO2 reaction, i.e. a vasoconstriction of blood vessels due to decreased CO2 pressure and thereby decrease in cerebral blood volume. Therefore, breathing changes should be monitored during brain studies involving speech when using functional near infrared spectroscopy (fNIRS) to ensure a correct interpretation of changes in hemodynamics and oxygenation.

The auxin influx carrier is essential for correct leaf positioning

Auxin is of vital importance in virtually every aspect of plant growth and development, yet, even after almost a century of intense study, major gaps in our knowledge of its synthesis, distribution, perception, and signal transduction remain. One unique property of auxin is its polar transport, which in many well-documented cases is a critical part of its mode of action. Auxin is actively transported through the action of both influx and efflux carriers. Inhibition of polar transport by the efflux inhibitor N-1-naphthylphthalamic acid (NPA) causes a complete cessation of leaf initiation, a defect that can be reversed by local application of the auxin, indole-3-acetic acid (IAA), to the responsive zone of the shoot apical meristem. In this study, we address the role of the auxin influx carrier in the positioning and outgrowth of leaf primordia at the shoot apical meristem of tomato. By using a combination of transport inhibitors and synthetic auxins, we demonstrate that interference with auxin influx has little effect on organ formation as such, but prevents proper localization of leaf primordia. These results suggest the existence of functional auxin concentration gradients in the shoot apical meristem that are actively set up and maintained by the action of efflux and influx carriers. We propose a model in which efflux carriers control auxin delivery to the shoot apical meristem, whereas influx and efflux carriers regulate auxin distribution within the meristem.

Ist es dem Israeliten, nach jüdischen Gesetzen, wohl erlaubt, einen falschen Eid zu leisten, wenn die Gesetzrolle, die er in seiner Hand hält, nicht correct ist?

Hrsg. von Jehuda

Record linkage to correct under-ascertainment of cancers in HIV cohorts: the Sinikithemba HIV clinic linkage project.

The surveillance of HIV-related cancers in South Africa is hampered by the lack of systematic collection of cancer diagnoses in HIV cohorts and the absence of HIV status in cancer registries. To improve cancer ascertainment and estimate cancer incidence, we linked records of adults (aged ≥ 16 years) on antiretroviral treatment (ART) enrolled at Sinikithemba HIV clinic, McCord Hospital in KwaZulu-Natal (KZN) with the cancer records of public laboratories in KZN province using probabilistic record linkage methods. We calculated incidence rates for all cancers, Kaposi sarcoma (KS), cervix, non-Hodgkin's lymphoma and non-AIDS defining cancers (NADCs) before and after inclusion of linkage-identified cancers with 95% confidence intervals (CI). A total of 8,721 records of HIV-positive patients were linked with 35,536 cancer records. Between 2004 and 2010 we identified 448 cancers, 82% (n=367) were recorded in the cancer registry only, 10% (n=43) in the HIV cohort only and 8% (n=38) both in the HIV cohort and the cancer registry. The overall cancer incidence rate in patients starting ART increased from 134 (95% CI 91-212) to 877 (95% CI 744-1,041) after inclusion of linkage-identified cancers. Incidence rates were highest for KS (432, 95% CI 341-555), followed by cervix (259, 95% CI 179-390) and NADCs (294, 95% CI 223-395) per 100,000 person-years. Ascertainment of cancer in HIV cohorts is incomplete, probabilistic record linkage is both feasible and essential for cancer ascertainment. This article is protected by copyright. All rights reserved.

Why do oil importers diversify their import sources politically? : evidence from U.S. firm-level data

International politics affects oil trade. But why? We construct a firm-level dataset for all U.S. oil-importing companies over 1986-2008 to examine what kinds of firms are more responsive to change in "political distance" between the U.S. and her trading partners, measured by divergence in their UN General Assembly voting patterns. Consistent with previous macro evidence, we first show that individual firms diversify their oil imports politically, even after controlling for unobserved firm heterogeneity. We conjecture that the political pattern of oil imports from these individual firms is driven by hold-up risks, because oil trade is often associated with backward vertical FDI. To test this hold-up risk hypothesis, we investigate heterogeneity in responses by matching transaction-level import data with firm-level worldwide reserves. Our results show that long-run oil import decisions are indeed more elastic for firms with oil reserves overseas than those without, although the reverse is true in the short run. We interpret this empirical regularity as that while firms trade in the spot market can adjust their imports immediately, vertically-integrated firms with investment overseas tend to commit to term contracts in the short run even though they are more responsive to changes in international politics in the long run.

Directives for a Correct Diagnosis

A special Working Group, to study and develop standars related to Building Restoration, Rehabilitation and Maintenance, was formed in January 2001 in AENOR (Spanish Association for Codes and Standars) under the management of the Department of Building Construction of the School of Architecture of Madrid (DCTA-UPM). Three groups were organized to deal with different topics: Diagnosis, Techiques and Materials, and Maintenance. In this paper the differents topics in which the Diagnosis Subgroup is working are described: historical studies, constructive description of the building and building pathology. These will be basic to carry out a correct diagnosis of any type of building, whether it is historic or not. In the development of such topics, the recognizable architectural values are justified as they are prior to the diagnosis stage. As an example of the subgroup work, several pathology cards are shown which include: longitudinal cracks of mechanical origin in beams of concrete structures, façade closings and claddings, and general symptoms of installation services.

Glu-tRNAGln amidotransferase: A novel heterotrimeric enzyme required for correct decoding of glutamine codons during translation

The three genes, gatC, gatA, and gatB, which constitute the transcriptional unit of the Bacillus subtilis glutamyl-tRNAGln amidotransferase have been cloned. Expression of this transcriptional unit results in the production of a heterotrimeric protein that has been purified to homogeneity. The enzyme furnishes a means for formation of correctly charged Gln-tRNAGln through the transamidation of misacylated Glu-tRNAGln, functionally replacing the lack of glutaminyl-tRNA synthetase activity in Gram-positive eubacteria, cyanobacteria, Archaea, and organelles. Disruption of this operon is lethal. This demonstrates that transamidation is the only pathway to Gln-tRNAGln in B. subtilis and that glutamyl-tRNAGln amidotransferase is a novel and essential component of the translational apparatus.

Sla1p Is a Functionally Modular Component of the Yeast Cortical Actin Cytoskeleton Required for Correct Localization of Both Rho1p-GTPase and Sla2p, a Protein with Talin Homology

SLA1 was identified previously in budding yeast in a genetic screen for mutations that caused a requirement for the actin-binding protein Abp1p and was shown to be required for normal cortical actin patch structure and organization. Here, we show that Sla1p, like Abp1p, localizes to cortical actin patches. Furthermore, Sla1p is required for the correct localization of Sla2p, an actin-binding protein with homology to talin implicated in endocytosis, and the Rho1p-GTPase, which is associated with the cell wall biosynthesis enzyme β-1,3-glucan synthase. Mislocalization of Rho1p in sla1 null cells is consistent with our observation that these cells possess aberrantly thick cell walls.  Expression of mutant forms of Sla1p in which specific domains were deleted showed that the phenotypes associated with the full deletion are functionally separable. In particular, a region of Sla1p encompassing the third SH3 domain is important for growth at high temperatures, for the organization of cortical actin patches, and for nucleated actin assembly in a permeabilized yeast cell assay. The apparent redundancy between Sla1p and Abp1p resides in the C-terminal repeat region of Sla1p. A homologue of SLA1 was identified in Schizosaccharomyces pombe. Despite relatively low overall sequence homology, this gene was able to rescue the temperature sensitivity associated with a deletion of SLA1 in Saccharomyces cerevisiae.

Nup93, a Vertebrate Homologue of Yeast Nic96p, Forms a Complex with a Novel 205-kDa Protein and Is Required for Correct Nuclear Pore Assembly

Yeast and vertebrate nuclear pores display significant morphological similarity by electron microscopy, but sequence similarity between the respective proteins has been more difficult to observe. Herein we have identified a vertebrate nucleoporin, Nup93, in both human and Xenopus that has proved to be an evolutionarily related homologue of the yeast nucleoporin Nic96p. Polyclonal antiserum to human Nup93 detects corresponding proteins in human, rat, and Xenopus cells. Immunofluorescence and immunoelectron microscopy localize vertebrate Nup93 at the nuclear basket and at or near the nuclear entry to the gated channel of the pore. Immunoprecipitation from both mammalian and Xenopus cell extracts indicates that a small fraction of Nup93 physically interacts with the nucleoporin p62, just as yeast Nic96p interacts with the yeast p62 homologue. However, a large fraction of vertebrate Nup93 is extracted from pores and is also present in Xenopus egg extracts in complex with a newly discovered 205-kDa protein. Mass spectrometric sequencing of the human 205-kDa protein reveals that this protein is encoded by an open reading frame, KIAAO225, present in the human database. The putative human nucleoporin of 205 kDa has related sequence homologues in Caenorhabditis elegans and Saccharomyces cerevisiae. To analyze the role of the Nup93 complex in the pore, nuclei were assembled that lack the Nup93 complex after immunodepletion of a Xenopus nuclear reconstitution extract. The Nup93-complex–depleted nuclei are clearly defective for correct nuclear pore assembly. From these experiments, we conclude that the vertebrate and yeast pore have significant homology in their functionally important cores and that, with the identification of Nup93 and the 205-kDa protein, we have extended the knowledge of the nearest-neighbor interactions of this core in both yeast and vertebrates.

Correct protein folding in glycerol

Water is the natural medium for protein folding, which is also used in all in vitro studies. In the present work, we posed, and answered affirmatively, a question of whether it is possible to fold correctly a typical protein in a nonaqueous solvent. To this end, unfolded and reduced hen egg-white lysozyme was refolded and reoxidized in glycerol containing varying amounts of water. The unfolded/reduced enzyme was found to regain spontaneously substantial catalytic activity even in the nearly anhydrous solvent; for example, the refolding yield in 99% glycerol was still some one-third of that in pure water, and one-half of that was regained even in 99.8% glycerol. The less than full recovery of the enzymatic activity in glycerol is, as in water, because of competing protein aggregation during the refolding. Lysozyme reoxidation in glycerol was successfully mediated by two dissimilar oxidizing systems, and the refolding yield was markedly affected by the pH of the last aqueous solution before the transfer into glycerol. No recovery of the lysozyme activity was observed when the refolding/reoxidation reaction was carried out in the denaturing solvent dimethyl sulfoxide. This study paves the way for a systematic investigation of the solvent effect on protein folding and demonstrates that water is not a unique milieu for this process.

On a psychophysical transformed-rule up and down method converging on a 75% level of correct responses

Tranformed-rule up and down psychophysical methods have gained great popularity, mainly because they combine criterion-free responses with an adaptive procedure allowing rapid determination of an average stimulus threshold at various criterion levels of correct responses. The statistical theory underlying the methods now in routine use is based on sets of consecutive responses with assumed constant probabilities of occurrence. The response rules requiring consecutive responses prevent the possibility of using the most desirable response criterion, that of 75% correct responses. The earliest transformed-rule up and down method, whose rules included nonconsecutive responses, did not contain this limitation but failed to become generally accepted, lacking a published theoretical foundation. Such a foundation is provided in this article and is validated empirically with the help of experiments on human subjects and a computer simulation. In addition to allowing the criterion of 75% correct responses, the method is more efficient than the methods excluding nonconsecutive responses in their rules.

Structure and function in rhodopsin: correct folding and misfolding in two point mutants in the intradiscal domain of rhodopsin identified in retinitis pigmentosa.

The rhodopsin mutants P23H and G188R, identified in autosomal dominant retinitis pigmentosa (ADRP), and the site-specific mutants D190A and DeltaY191-Y192 were expressed in COS cells from synthetic mutant opsin genes containing these mutations. The proteins expressed from P23H and D190A partially regenerated the rhodopsin chromophore with 11-cis-retinal and were mixtures of the correctly folded (retinal-binding) and misfolded (non-retinal-binding) opsins. The mixtures were separated into pure, correctly folded mutant rhodopsins and misfolded opsins. The proteins expressed from the ADRP mutant G188R and the mutant DeltaY191-Y192 were composed of totally misfolded non-retinal-binding opsins. Far-UV CD spectra showed that the correctly folded mutant rhodopsins had helical content similar to that of the wild-type rhodopsin, whereas the misfolded opsins had helical content 50-70% of the wild type. The near-UV CD spectra of the misfolded mutant proteins lack the characteristic band pattern seen in the wild-type opsin, indicative of a different tertiary structure. Further, whereas the folded mutant rhodopsins were essentially resistant to trypsin digestion, the misfolded opsins were degraded to small fragments under the same conditions. Therefore, the misfolded opsins appear to be less compact in their structures than the correctly folded forms. We suggest that most, if not all, of the point mutations in the intradiscal domain identified in ADRP cause partial or complete misfolding of rhodopsin.

Structure and function in rhodopsin: correct folding and misfolding in point mutants at and in proximity to the site of the retinitis pigmentosa mutation Leu-125-->Arg in the transmembrane helix C.

L125R is a mutation in the transmembrane helix C of rhodopsin that is associated with autosomal dominant retinitis pigmentosa. To probe the orientation of the helix and its packing in the transmembrane domain, we have prepared and studied the mutations E122R, I123R, A124R, S127R, L125F, and L125A at, and in proximity to, the above mutation site. Like L125R, the opsin expressed in COS-1 cells from E122R did not bind 11-cis-retinal, whereas those from I123R and S127R formed the rhodopsin chromophore partially. A124R opsin formed the rhodopsin chromophore (lambda max 495 nm) in the dark, but the metarhodopsin II formed on illumination decayed about 6.5 times faster than that of the wild type and was defective in transducin activation. The mutant opsins from L125F and L125A bound 11-cis-retinal only partially, and in both cases, the mixtures of the proteins produced were separated into retinal-binding and non-retinal-binding (misfolded) fractions. The purified mutant rhodopsin from L125F showed lambda max at 500 nm, whereas that from L125A showed lambda max at 503 nm. The mutant rhodopsin L125F showed abnormal bleaching behavior and both mutants on illumination showed destabilized metarhodopsin II species and reduced transducin activation. Because previous results have indicated that misfolding in rhodopsin is due to the formation of a disulfide bond other than the normal disulfide bond between Cys-110 and Cys-187 in the intradiscal domain, we conclude from the misfolding in mutants L125F and L125A that the folding in vivo in the transmembrane domain is coupled to that in the intradiscal domain.