Aseptic precautions for inserting an epidural catheter.
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Analgesia, Epidural↗
Biomedical subjects
S Cohen
Publications and source records attributed to S Cohen.
Increased growth of young citrus trees under reduced radiation load in a semi-arid climate.
This study investigated the effects of radiation heat-load reduction by shading on the growth and development of citrus trees in a warm subtropical region. The experiment was conducted from mid-June until late October when daily maximal air temperature averaged 29.3 degrees C. Two-year-old de-fruited Murcott tangor (Citrus reticulata BlancoxCitrus sinensis (L.) Osb.) trees were grown under 30% or 60% shade tunnels, or 60% flat shade (providing midday shade only), using highly reflective aluminized nets. Non-shaded trees were used as the control. Shading reduced direct more than diffuse radiation. Daily radiation was reduced by 35% for the 30% Tunnel and 60% Flat treatments, and by 55% for the 60% Tunnel. Two days of intensive measurement showed that shading increased average sunlit leaf conductance by 44% and photosynthesis by 29%. Shading did not significantly influence root and stem dry weight growth, but it increased the increment in leaf dry weight during the three month period by an average of 28% relative to the control, while final tree height in the 30% Tunnel treatment exceeded the control by 35%. Shoot to root and shoot mass ratios increased and root mass ratio decreased due to shading because of the increase in leaf dry weight. Shading increased starch concentration in leaves while the shadiest treatment, 60% Tunnel, decreased starch concentration in the roots. Carbon isotope ratio (delta(13)C) of exposed leaves that developed under shading was significantly reduced by 1.9 per thousand in the 60% Tunnel, indicating that shading increased CO(2) concentrations at the chloroplasts (C(c)), as would be expected from increased conductance. Substomatal CO(2) concentrations, C(i), computed from leaf net CO(2) assimilation rate and conductance values, also indicate that shading increases internal CO(2) concentrations. Based on tree dry mass, tree height, and total carbohydrates fractions, the 30% Tunnel and the 60% Flat were the optimal shade treatments.
Citrus↗
Use of a promoter trap system in Bacillus anthracis and Bacillus subtilis for the development of recombinant protective antigen-based vaccines.
We have recently reported Bacillus anthracis attenuated live vaccine strains efficiently expressing recombinant protective antigen (rPA) and have shown a direct correlation between the level of rPA secreted by these cells and efficacy (S. Cohen, I. Mendelson, Z. Altboum, D. Kobiler, E. Elhanany, T. Bino, M. Leitner, I. Inbar, H. Rosenberg, Y. Gozes, R. Barak, M. Fisher, C. Kronman, B. Velan, and A. Shafferman, Infect. Immun. 68:4549-4558, 2000). To isolate more potent Bacillus promoters for a further increase in the production of rPA, we developed a promoter trap system based on various gfp reporter genes adapted for use in both Bacillus subtilis and B. anthracis backgrounds. Accordingly, a B. anthracis library of 6,000 clones harboring plasmids with chromosomal B. anthracis DNA fragments inserted upstream from gfpuv was constructed. Based on fluorescence intensity, 57 clones carrying potentially strong promoters were identified, some of which were DNA sequenced. The most potent B. anthracis promoter identified (Pntr; 271 bp) was 500 times more potent than the native pagA promoter and 70 times more potent than the alpha-amylase promoter (Pamy). This very potent promoter was tested along with the other promoters (which are three, six, and eight times more potent than Pamy) for the ability to drive expression of rPA in either B. subtilis or B. anthracis. The number of cell-associated pre-PA molecules in B. anthracis was found to correlate well with the strength of the promoter. However, there appeared to be an upper limit to the amount of mature PA secreted into the medium, which did not exceed that driven by Pamy. Furthermore, the rPA constructs fused to the very potent promoters proved to be deleterious to the bacterial hosts and consequently led to genetic instability of the PA expression plasmid. Immunization with attenuated B. anthracis expressing rPA under the control of promoters more potent than Pamy was less efficient in eliciting anti-PA antibodies than that attained with Pamy. The results are consistent with the notion that overexpression of PA leads to severe secretion stress and have practical implications for the design of second-generation rPA-based vaccines.
Animals↗
Genome-based bioinformatic selection of chromosomal Bacillus anthracis putative vaccine candidates coupled with proteomic identification of surface-associated antigens.
Bacillus anthracis (Ames strain) chromosome-derived open reading frames (ORFs), predicted to code for surface exposed or virulence related proteins, were selected as B. anthracis-specific vaccine candidates by a multistep computational screen of the entire draft chromosome sequence (February 2001 version, 460 contigs, The Institute for Genomic Research, Rockville, Md.). The selection procedure combined preliminary annotation (sequence similarity searches and domain assignments), prediction of cellular localization, taxonomical and functional screen and additional filtering criteria (size, number of paralogs). The reductive strategy, combined with manual curation, resulted in selection of 240 candidate ORFs encoding proteins with putative known function, as well as 280 proteins of unknown function. Proteomic analysis of two-dimensional gels of a B. anthracis membrane fraction, verified the expression of some gene products. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analyses allowed identification of 38 spots cross-reacting with sera from B. anthracis immunized animals. These spots were found to represent eight in vivo immunogens, comprising of EA1, Sap, and 6 proteins whose expression and immunogenicity was not reported before. Five of these 8 immunogens were preselected by the bioinformatic analysis (EA1, Sap, 2 novel SLH proteins and peroxiredoxin/AhpC), as vaccine candidates. This study demonstrates that a combination of the bioinformatic and proteomic strategies may be useful in promoting the development of next generation anthrax vaccine.
Adhesins, Bacterial↗
Alveolar soft part sarcoma--reciprocal translocation between chromosome 17q25 and Xp11. Report of a case with metastases at presentation and review of the literature.
The molecular pathogenesis of alveolar soft part sarcoma, a rare tumor with uncertain histogenesis, was elucidated recently and was shown to be due to a translocation between chromosome 17q25 and Xp11 resulting in a fusion product between TFE3 (a transcription factor gene) at chromosome Xp11 and a novel gene designated as ASPL at chromosome 17q25. This results in the transcriptional dysregulation in the pathogenesis of this neoplasm. Of the 12 cases reported so far, the translocation was due to non-reciprocal translocation in 11 cases with only one case demonstrating a reciprocal translocation with respective fusion products. We report yet another case with reciprocal translocation between chromosomes 17q25 and Xp11 with TFE3/ASPL fusion product who presented with metastatic disease. A standard cytogenetic analysis of primary tumor cells with G-banding revealed an abnormal karyotype: 46, X, t(X;17)(p11;q25)[15]/46,XX[5]. PCR analysis of the frozen tumor tissue revealed a type 1 fusion product as described in the literature. We demonstrate a rare cytogenetic abnormality in ASPS, namely reciprocal translocation between chromosomes 17q25 and Xp11 with demonstration of molecular fusion product between TFE3 and ASPL in a patient who initially presented with pulmonary metastases.
Adult↗
Biophoton emission of human body.
For the first time systematic measurements of the "ultraweak" photon emission of the human body (biophotons) have been performed by means of a photon detector device set up in darkness. About 200 persons have been investigated. In a particular case one person has been examined daily over several months. It turned out that this biophoton emission reflects, (i) the left-right symmetry of the human body; (ii) biological rhythms such as 14 days, 1 month, 3 months and 9 months; (iii) disease in terms of broken symmetry between left and right side; and (iv) light channels in the body, which regulate energy and information transfer between different parts. The results show that besides a deeper understanding of health, disease and body field, this method provides a new powerful tool of non-invasive medical diagnosis in terms of basic regulatory functions of the body.
Humans↗
Organ donors > or = 60 years: harvesting disparities in French regional areas.
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Adult↗
The role of anti-endothelial cell antibodies in Kawasaki disease - in vitro and in vivo studies.
Kawasaki disease (KD) is a systemic vasculitis with cardiac and noncardiac complications. Anti--endothelial cell antibodies (AECA) are found among many patients with KD. The aim of this study was to investigate the pathogenic role of AECA in KD using in vitro and in vivo experimental models. F(ab)2 fragments of IgG-AECA and IgM-AECA were affinity purified from a patient with active KD. Their endothelial binding and ability to induce a pro-adhesive and a pro-inflammatory phenotype were evaluated in vitro. Twenty Balb/C mice were immunized with KD-AECA or with control Ig (N-Ig) to induce AECA in a murine model by the idiotypic manipulation method. Both KD-AECA isotypes bind significantly to human umbilical vein endothelial cell (HUVEC) compared to N-Ig. The in vitro activity was demonstrated by the antibodies ability to activate endothelial cells resulting in increased IL-6 secretion, adhesion molecule expression and monocytic cell line (U937) adherence to HUVEC. Five of the mice that received KD-AECA developed murine AECA after 3 months. None of the mice that received N-Ig produced AECA. The murine AECA increased monocyte adhesion to EC in vitro, similarly to the AECA used for immunization. Furthermore, all the mice that developed AECA had proteinuria and IgG deposition in the renal mesangium. No histological or immunofluorescence evidence of cardiac vasculitis could be detected. AECA might play a role in the emergence of some of KD manifestations.
Animals↗
A simple technique to reduce the incidence of accidental dural puncture.
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Analgesia, Epidural↗
Search for potential vaccine candidate open reading frames in the Bacillus anthracis virulence plasmid pXO1: in silico and in vitro screening.
A genomic analysis of the Bacillus anthracis virulence plasmid pXO1, aimed at identifying potential vaccine candidates and virulence-related genes, was carried out. The 143 previously defined open reading frames (ORFs) (R. T. Okinaka, K. Cloud, O. Hampton, A. R. Hoffmaster, K. K. Hill, P. Keim, T. M. Koehler, G. Lamke, S. Kumano, J. Mahillon, D. Manter, Y. Martinez, D. Ricke, R. Svensson, and P. J. Jackson, J. Bacteriol. 181:6509-6515, 1999) were subjected to extensive sequence similarity searches (with the nonredundant and unfinished microbial genome databases), as well as motif, cellular location, and domain analyses. A comparative genomics analysis was conducted with the related genomes of Bacillus subtilis, Bacillus halodurans, and Bacillus cereus and the pBtoxis plasmid of Bacillus thuringiensis var. israeliensis. As a result, the percentage of ORFs with clues about their functions increased from approximately 30% (as previously reported) to more than 60%. The bioinformatics analysis permitted identification of novel genes with putative relevance for pathogenesis and virulence. Based on our analyses, 11 putative proteins were chosen as targets for functional genomics studies. A rapid and efficient functional screening method was developed, in which PCR-amplified full-length linear DNA products of the selected ORFs were transcribed and directly translated in vitro and their immunogenicities were assessed on the basis of their reactivities with hyperimmune anti-B. anthracis antisera. Of the 11 ORFs selected for analysis, 9 were successfully expressed as full-length polypeptides, and 3 of these were found to be antigenic and to have immunogenic potential. The latter ORFs are currently being evaluated to determine their vaccine potential.
Animals↗
[Geographic variations in access to heart transplantation in France].
This study was undertaken to determine whether there were regional variations in the access to the national waiting list for cardiac transplantation and in access to cardiac transplantation itself in France. The incidence of inscription on the waiting list for transplantation was calculated for new candidates living in each region between 1998 and 2000, indicating the level of access to the waiting list. The average interval before transplantation between 1995 and 2000 was calculated by the Kaplan-Meier method. The regional lack of transplant organs was estimated by the ratio of the difference between patients inscribed on the waiting list and those operated, over the number of patients operated. The overall national incidence of inscription of the waiting list for cardiac transplantation was 8 new patients per year per million inhabitants with a range of 1.7 in Corsica to 12.1 in Lorraine. The regional incidence was lower than the national reference in 5 regions in higher in 4 regions. There was a strong attraction of patients to the Ile-de-France, Pays de la Loire and Rhone-Alpes regions. The average waiting time for transplantation in France was 3.7 months and ranged from 1.2 months in Brittany to 15.4 months in Aquitaine (p < 0.001). The degree of regional lack of transplant organs was significantly and positively correlated with the average waiting time for transplantation. The results of this study show that there are regional differences in the incidence of inscription on the waiting list for cardiac transplantation in France and a significant variation in waiting times for cardiac transplantation, and therefore, in access to cardiac transplantation.
France↗
The experimentally elusive oxidant of cytochrome P450: a theoretical "trapping" defining more closely the "real" species.
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Cytochrome P-450 Enzyme System↗
Polyethylated aromatic rings: conformation and rotational barriers of 1,2,3,4,5,6,7,8-octaethylanthracene, 1,2,3,4,6,7,8-heptaethylfluorene, and 1,2,3,4,5,6,7,8-octaethylfluorene.
1,2,3,4,5,6,7,8-Octaethylanthracene (5), 1,2,3,4,6,7,8-heptaethylfluorene (7), and 1,2,3,4,5,6,7,8-octaethylfluorene (8) were synthesized by Friedel-Crafts ethylations of 9,10-dihydroanthracene and fluorene. MM3 calculations indicate that the two ethylated six-membered rings of 5 and 7 are conformationally independent. According to the calculations, two low-energy conformers of each compound are possible with the ethyl groups attached to the external aryl rings arranged in an alternated "up-down" orientation. MM3 calculations indicate that in the lowest energy conformation the central fluorene core of 8 adopts a twisted conformation to avoid repulsive steric interactions between the ethyls at the bay region. Two fully alternated up-down conformations are possible for 8, differing in the orientation ("in" or "out") of the ethyls in the bay region. MM3 calculations predict that the lowest energy conformer is the fully alternated "out" form of C(2)() symmetry. The rotational barriers of 5, 7, and 8 are in the 8.7-11.3 kcal mol(-1) range, the largest barrier corresponding to the more crowded octaethylfluorene 8. Anthracene 5 adopts in the crystal a conformation of approximate C(2)(h) symmetry with pairs of peri groups on the same edge of the molecule oriented syn. The conformations adopted in the crystal by 7 and 8 do not correspond to the calculated lowest energy form. In the conformation of 7 in the crystal the ethyl groups on the trisubstituted ring adopt the unusual all syn arrangement. Octaethylfluorene 8 adopts a conformation with a twisted central fluorene core but with a syn arrangement of a pair of vicinal ethyl groups.
Journal Article↗
Annexin-1 is abnormally expressed in fragile X syndrome: two-dimensional electrophoresis study in lymphocytes.
The search for targets of FMRP (the product of FMR1, the mutated gene in Fragile X syndrome) has predominantly focused on identifying transcripts that are regulated by this RNA-binding protein. This study introduces the use of two-dimensional gel electrophoresis (2D PAGE) as a novel approach for demonstrating changes in protein synthesis secondary to FMRP deficit. By a standardized 2D PAGE protocol, we studied leukocyte homogenates from 30 males with different patterns of FMR1 mutation and different levels of FMRP. Samples from these subjects were compared to those of 12 normal control males and eight subjects with other mental retardation-associated conditions (i.e., Rett and Down syndromes). We found an abnormal pattern of a major leukocytic protein, identified by 2D PAGE datasets and immunoblotting as annexin-1 (Anx-1). Anx-1 appeared in subjects with Fragile X as multiple rather than 1-2 spots, at approximately 37 kd, in the pI 5-7 range. The presence and intensity of this Anx-1 pattern was relatively independent of Anx-1 levels and inversely related to total and high MW FMRP immunoreactivities. Based on the 2D PAGE pattern, without obvious MW change, and on dephosphorylation assays, we concluded that Anx-1's abnormality represents an aberrant posttranslational modification other than phosphorylation. Comparisons of our data with published cytoskeletal protein 2D profiles suggest that Anx-1 may be abnormally acetylated and, consequently, incapable of establishing appropriate N-terminal protein-protein interactions. In addition to its peripheral anti-inflammatory function, Anx-1 mediates glucocorticoid inhibition of the hypothalamo-pituitary-adrenal axis. As the latter seems to be disrupted in Fragile X syndrome, the reported Anx-1 abnormality could be responsible for some aspects of the Fragile X neurobehavioral phenotype. Our data also emphasize the feasibility of using 2D PAGE for disclosing molecular abnormalities in Fragile X and other genetic disorders.
Adolescent↗
Interactions between adaptor protein-1 of the clathrin coat and microtubules via type 1a microtubule-associated proteins.
The classical view suggests that adaptor proteins of the clathrin coat mediate the sorting of cargo protein passengers into clathrin-coated pits and the recruitment of clathrin into budding areas in the donor membrane. In the present study, we provide biochemical and morphological evidence that the adaptor protein 1 (AP-1) adaptor of the trans-Golgi network clathrin interacts with microtubules. AP-1 in cytosolic extracts interacted with in vitro assembled microtubules, and these interactions were inhibited by ATP depletion of the extracts or in the presence of 5'-adenylylimidodiphosphate. An overexpressed gamma-subunit of the AP-1 complex associated with microtubules, suggesting that this subunit may mediate the interaction of AP-1 with the cytoskeleton. Purified AP-1 did not interact with purified microtubules, but interaction occurred when an isolated microtubule-associated protein fraction was added to the reaction mix. The gamma-adaptin subunit of AP-1 specifically co-immunoprecipitated with a microtubule-associated protein of type 1a from rat brain cytosol. This suggests that type 1a microtubule-associated protein may mediate the association of AP-1 with microtubules in the cytoplasm. The microtubule binding activity of AP-1 was markedly inhibited in cytosol of mitotic cells. By means of its interaction with microtubule-associated proteins, we propose novel roles for AP-1 adaptors in modulating the dynamics of the cytoskeleton, the stability and shape of coated organelles, and the loading of nascent AP-1-coated vesicles onto appropriate microtubular tracks.
Adaptor Protein Complex gamma Subunits↗
A novel cell-free system reveals a mechanism of circular DNA formation from tandem repeats.
One characteristic of genomic plasticity is the presence of extrachromosomal circular DNA (eccDNA). High levels of eccDNA are associated with genomic instability, exposure to carcinogens and aging. We have recently reported developmentally regulated formation of eccDNA that occurs preferentially in pre-blastula Xenopus laevis embryos. Multimers of tandemly repeated sequences were over-represented in the circle population while dispersed sequences were not detected, indicating that circles were not formed at random from any chromosomal sequence. Here we present detailed mechanistic studies of eccDNA formation in a cell-free system derived from Xenopus egg extracts. We show that naked chromosomal DNA from sperm or somatic tissues serves as a substrate for direct tandem repeat circle formation. Moreover, a recombinant bacterial tandem repeat can generate eccDNA in the extract through a de novo mechanism which is independent of DNA replication. These data suggest that the presence of a high level of any direct tandem repeat can confer on DNA the ability to be converted into circular multimers in the early embryo irrespective of its sequence and that homologous recombination is involved in this process.
Animals↗
Processing of p105 is inhibited by docking of p50 active subunits to the ankyrin repeat domain, and inhibition is alleviated by signaling via the carboxyl-terminal phosphorylation/ ubiquitin-ligase binding domain.
Processing of the p105 precursor to generate the p50 subunit of the nuclear factor kappaB transcription factor is an exceptional case in which the ubiquitin system is involved in limited processing rather than in complete destruction of the target substrate. A Gly-rich region "stop" signal in the middle of the molecule along with a neighboring downstream ubiquitination, and probably an E3 anchoring domain, have been demonstrated to be important for processing. In addition, we have shown that IkappaB kinase-mediated phosphorylation of the C-terminal domain leads to recruitment of the SCF(beta)-TrCP ubiquitin ligase with subsequent accelerated ubiquitination and processing/degradation of the precursor (Orian, A., Gonen, H., Bercovich, B., Fajerman, I., Eytan, E., Israël, A., Mercurio, F., Iwai, K., Schwartz, A. L., and Ciechanover, A. (2000) EMBO J. 19, 2580-2591). Here we show that processing of p105 molecules that contain more then four ankyrin repeats, but lack the C-terminal phosphorylation/ubiquitin ligase binding domain, is strongly inhibited by docked p50 subunits. Inhibition is caused by interference with the function of the proteasome, as conjugation is not affected. Inhibition is alleviated after IkappaB kinase phosphorylation of the C-terminal domain leads to accelerated, beta-TrCP-mediated ubiquitination and processing/degradation of p105. We suggest that under basal conditions, slow generation of p50 probably involves the mid-molecule ubiquitination/E3 recognition motif. Following stimulation, the C-terminal domain is involved in rapid processing/degradation of p105 with release of a large amount of the stored subunits that now become transcriptionally active.
Animals↗
Stereochemistry of a spherand-type calixarene.
The stereochemistry of the spherand-type calixarene 2a is analyzed in terms of the configuration of the three 2,2'-dihydroxybiphenyl subunits (R or S) and the disposition of the methylene groups (crown or twist). X-ray crystallography indicates that the neutral 2a and its mono- or dianion (in form of the salts 2a(-) x C(5)H(5)NH(+) and 2a(2)(-) x 2Et(3)NH(+)) exist essentially in the same conformation (RRS/SSR-twist). This asymmetric RRS/SSR-twist form is the lowest energy conformer according to molecular mechanics calculations. Low-temperature (1)H NMR data indicate the presence of a major conformer of C(1) symmetry, in agreement with a RRS/SSR-twist form. The lowest energy topomerization pathway mutually exchanges two pairs of methylene protons and is ascribed to an enantiomerization process involving rotation around an Ar-Ar bond.
Journal Article↗