bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Epidemiology of
Serratia marcescens
in Two Hospitals in Danzig, Poland, over a 5-Year Period
Authors: Naumiuk Łukasz , Baraniak Anna , Gniadkowski Marek , Krawczyk Beata , Rybak Bartosz , Sadowy Ewa , Samet Alfred , Kur Józef
Published: July 2004

The history of the
Serratia marcescens
population in two hospitals in Danzig, Poland, over a 5-year period was analyzed in a study that combined MIC evaluation, typing by randomly amplified polymorphic DNA (RAPD) analysis and pulsed-field gel electrophoresis, and analysis of extended-spectrum β-lactamases (ESBLs). We analyzed 354 isolates collected from 341 patients in two teaching hospitals in Danzig, Poland, from 1996 to 2000. The antimicrobial susceptibility profiles varied greatly, and for resistance to newer β-lactams, probable AmpC cephalosporinase derepression and ESBL production occurred in about 23 and 19% of the isolates, respectively. RAPD typing, by which 69 types were discerned altogether, revealed a high degree of clonal diversity among the populations. However, the four most prevalent types were highly predominant, grouping approximately 71% of the isolates studied. These clones were observed in the two hospitals and were strong contributors to both outbreaks and the background of endemicity of the
S. marcescens
infections. Some of the strains that were not so widely spread (12 RAPD types; ∼14% of the isolates) were responsible for several smaller outbreaks, and the remaining isolates represented unique RAPD types (53 types; ∼15% of the isolates) and were probably sporadic introductions from other environments. ESBLs were identified in several different clones, and some of these had most likely already been introduced into the hospitals as ESBL producers, whereas the others acquired the ESBL-encoding genes from other enterobacterial strains in these environments. The CTX-M-3 enzyme, which is widely observed in Poland, was the most common ESBL type among the
S. marcescens
isolates, followed by TEM-47 and SHV-5. The complex epidemiology of ESBLs, especially in 1999 and 2000, must have arisen from the introduction of ESBL producers from other centers, their clonal dissemination, and the constant penetration of the
S. marcescens
populations with plasmids with ESBL genes. Multiple
S. marcescens
isolates were obtained from 11 patients, who probably represented both patients with recolonizations and reinfections and patients with recurrences of infections with the evolution of the strain's susceptibility.
Geographic Variation in the Susceptibilities of Invasive Isolates of
Candida glabrata
to Seven Systemically Active Antifungal Agents: a Global Assessment from the ARTEMIS Antifungal Surveillance Program Conducted in 2001 and 2002
Authors: Pfaller M. A. , Messer S. A. , Boyken L. , Tendolkar S. , Hollis R. J. , Diekema D. J.
Published: July 2004

We examined the susceptibilities to amphotericin B, flucytosine, fluconazole, posaconazole, ravuconazole, voriconazole, and caspofungin of 601 invasive isolates of
Candida glabrata
and grouped the isolates by geographic location: North America (331 isolates), Latin America (58 isolates), Europe (135 isolates), and Asia-Pacific (77 isolates). Caspofungin (MIC at which 90% of isolates tested are susceptible [MIC
90
], 0.12 μg/ml; 100% of strains are susceptible [S] at a MIC of ≤1 μg/ml) and flucytosine (MIC
90
, 0.12 μg/ml; 99.2% S) were the most active agents in all geographic regions. Fluconazole susceptibility was highest in the Asia-Pacific region (80.5% S, 3.9% resistant [R]) and lowest in North America (64% S, 10.3% R) and Latin America (62.1% S, 3.4% R). The extended-spectrum triazoles were most active in the Asia-Pacific region (90 to 96.1% S) and least active in North America (82.5 to 90.3% S). All 46 isolates that were resistant to fluconazole were susceptible to caspofungin (MIC
90
, 0.06 μg/ml) and flucytosine (MIC
90
, 0.12 μg/ml) and exhibited variable cross-resistance to posaconazole, ravuconazole, and voriconazole.
Detection and Typing of Human Papillomavirus by E6 Nested Multiplex PCR
Authors: Sotlar K. , Diemer D. , Dethleffs A. , Hack Y. , Stubner A. , Vollmer N. , Menton S. , Menton M. , Dietz K. , Wallwiener D. , Kandolf R. , Bültmann B.
Published: July 2004

A nested multiplex PCR (NMPCR) assay that combines degenerate E6/E7 consensus primers and type-specific primers was evaluated for the detection and typing of human papillomavirus (HPV) genotypes 6/11, 16, 18, 31, 33, 35, 39, 42, 43, 44, 45, 51, 52, 56, 58, 59, 66, and 68 using HPV DNA-containing plasmids and cervical scrapes (
n
= 1,525). The performance of the NMPCR assay relative to that of conventional PCR with MY09-MY11 and GP5+-GP6+ primers, and nested PCR with these two primer sets (MY/GP) was evaluated in 495 cervical scrapes with corresponding histologic and cytologic findings. HPV prevalence rates determined with the NMPCR assay were 34.7% (102 of 294) in the absence of cervical intraepithelial neoplasia (CIN 0), 94.2% (113 of 120) in the presence of mild or moderate dysplasia (CIN I/II), and 97.8% (44 of 45) in the presence of severe dysplasia (CIN III). The combination of all four HPV detection methods applied in the study was taken as “gold standard”: in all three morphological subgroups the NMPCR assay had significantly (
P
< 0.0001) higher sensitivities than the MY09-MY11 and GP5+-GP6+ assays and sensitivities comparable or equal to those of the MY/GP assay. All 18 HPV genotypes investigated were detected among the clinical samples. The ratio of high- to low-risk HPV genotypes increased from 4:1 (80 of 103) in CIN 0 to 19:1 (149 of 157) in CIN I to III. Multiple infections were detected in 47.9% (124 of 259) of the patients. In conclusion, the novel NMPCR method is a sensitive and useful tool for HPV DNA detection, especially when exact HPV genotyping and the identification of multiple HPV infections are required.
Discovery of Novel Human and Animal Cells Infected by the Severe Acute Respiratory Syndrome Coronavirus by Replication-Specific Multiplex Reverse Transcription-PCR
Authors: Gillim-Ross Laura , Taylor Jill , Scholl David R. , Ridenour Jared , Masters Paul S. , Wentworth David E.
Published: July 2004

The severe acute respiratory syndrome coronavirus (SARS-CoV) is the causative agent of the recent outbreak of severe acute respiratory syndrome. VeroE6 cells, fetal rhesus monkey kidney cells, and human peripheral blood mononuclear cells were the only cells known to be susceptible to SARS-CoV. We developed a multiplex reverse transcription-PCR assay to analyze the susceptibility of cells derived from a variety of tissues and species to SARS-CoV. Additionally, productive infection was determined by titration of cellular supernatants. Cells derived from three species of monkey were susceptible to SARS-CoV. However, the levels of SARS-CoV produced differed by 4 log
10
. Mink lung epithelial cells (Mv1Lu) and R-Mix, a mixed monolayer of human lung-derived cells (A549) and mink lung-derived cells (Mv1Lu), are used by diagnostic laboratories to detect respiratory viruses (e.g., influenza virus); they were also infected with SARS-CoV, indicating that the practices of diagnostic laboratories should be examined to ensure appropriate biosafety precautions. Mv1Lu cells produce little SARS-CoV compared to that produced by VeroE6 cells, which indicates that they are a safer alternative for SARS-CoV diagnostics. Evaluation of cells permissive to other coronaviruses indicated that these cell types are not infected by SARS-CoV, providing additional evidence that SARS-CoV binds an alternative receptor. Analysis of human cells derived from lung, kidney, liver, and intestine led to the discovery that human cell lines were productively infected by SARS-CoV. This study identifies new cell lines that may be used for SARS-CoV diagnostics and/or basic research. Our data and other in vivo studies indicate that SARS-CoV has a wide host range, suggesting that the cellular receptor(s) utilized by SARS-CoV is highly conserved and is expressed by a variety of tissues.
Performance of the MagNA Pure LC Robot for Extraction of
Chlamydia trachomatis
and
Neisseria gonorrhoeae
DNA from Urine and Swab Specimens
Authors: Dalesio Nicholas , Marsiglia Vince , Quinn Andrew , Quinn Thomas C. , Gaydos Charlotte A.
Published: July 2004

DNA from uncentrifuged urines (
n
= 195 and
n
= 202) and cervical swabs (
n
= 221 and
n
= 601) was extracted by the MagNA Pure LC robot and the Amplicor method to validate the robot's extraction for
Chlamydia trachomatis
and
Neisseria gonorrhoeae
testing by Roche PCR. The robot provided a highly sensitive and specific method of DNA extraction.
Detection of
Pneumocystis jiroveci
in Respiratory Specimens by Four Staining Methods
Authors: Procop G. W. , Haddad S. , Quinn J. , Wilson M. L. , Henshaw N. G. , Reller L. B. , Artymyshyn R. L. , Katanik M. T. , Weinstein M. P.
Published: July 2004

We examined four staining methods on replicate smears of 313 respiratory specimens submitted for
Pneumocystis jiroveci
examination. The sensitivity and specificity of Calcofluor white stain (CW) were 73.8 and 99.6%, respectively. The sensitivity and specificity of Grocott-Gomori methenamine silver stain (GMS) were 79.4 and 99.2%, respectively. The sensitivity and specificity of Diff-Quik stain were 49.2 and 99.6%, respectively. The sensitivity and specificity of Merifluor Pneumocystis stain were 90.8 and 81.9%, respectively. Only CW and GMS had positive and negative predictive values of >90%.
Clinical and Microbiological Analysis of Bloodstream Infections Caused by
Chryseobacterium meningosepticum
in Nonneonatal Patients
Authors: Lin Pen-Yi , Chu Chishih , Su Lin-Hui , Huang Chung-Tsui , Chang Wen-Ya , Chiu Cheng-Hsun
Published: July 2004

Chryseobacterium meningosepticum
bloodstream infections in 11 nonneonatal patients were reported. More than half of the infections were community acquired. PCR assays indicated that the organisms produced extended-spectrum β-lactamases as well as metallo-β-lactamases. Genotyping showed diverse fingerprints among the isolates. Six patients survived without appropriate antibiotic treatment. Host factors are the major determinant of the outcomes of
C. meningosepticum
infections.
Prosthetic Mitral Valve Endocarditis Due to
Ochrobactrum anthropi
: Case Report
Authors: Romero Gómez M. P. , Peinado Esteban A. M. , Sobrino Daza J. A. , Sáez Nieto J. A. , Alvarez D. , Peña García P.
Published: July 2004

We describe a case of infective endocarditis in a prosthetic mitral valve due to
Ochrobactrum anthropi
. Although
O. anthropi
is an emerging pathogen in immunocompromised patients, infections with the bacterium have very rarely been documented in healthy hosts, and endocarditis is rare. To our knowledge, only two cases of
O. anthropi
endocarditis have been reported in the medical literature.
Processing of Composites: Simulations of the Draping of Fabrics with Updated Material Behaviour Law
Authors: Dong L. , Lekakou C. , Bader M. G.
Published: July 2004

In the processing of composites, fibre reinforcement is draped over complex three dimensional geometries, yielding local variations in the fibre volume fraction and fibre orientation with subsequent effects on the permeability of the reinforcement during resin infiltration and on the properties of the composite product. This study presents computer simulations of the draping of fabrics by following a mechanical, finite element approach. The fabric is considered as a solid continuum with mechanical properties and friction properties at interfaces. The problem is solved by applying an explicit dynamic finite element analysis. In order to incorporate the large shear deformation of fabric during draping, an updated material behaviour law was formulated on the basis of changing fibre directions. The model was implemented in a user computer subroutine and tested first in case-studies of simple in-plane shear where the predictions were also compared with experimental data from a picture frame type of shear test. Thereafter, numerical simulations focused on the draping of a fabric in a “hat” shaped mould, comprising a hemispherical cup with a wide flat rim. The predictions were compared with predictions from similar simulations without the updated material behaviour law, experimental data and predictions from a “fishnet” algorithm.
Impregnation of Compressible Fiber Mats with a Thermoplastic Resin. Part II: Experiments
Authors: Michaud V. , Törnqvist R. , Månson J. -A. E.
Published: July 2004

The impregnation of compressible glass fiber mats by a thermoplastic resin in the transverse direction is investigated with application to the Glass Mat reinforced Thermoplastics (GMT) lamination process in a double belt press. Amodel proposed in Part I to simulate the kinetics of impregnation and the evolution of the fiber volume fraction profile as the resin front progresses across the fiber mat, as well as after macro-impregnation is complete, is further developed to include micro-impregnation effects. The predictions are compared with experimental results obtained using model systems such as polyethylene glycol and glass fiber mats, as well as an industrially relevant system consisting of polypropylene and glass fiber mats used in the production of GMT blanks. It is shown that significant compression of the fiber mat may occur during impregnation, with subsequent relaxation on a much longer time-scale. Also, fiber bundle impregnation generally occurs after macro-impregnation is complete, the driving force being the local pressure in the resin around the bundles, dictated by the local state of compression of the mat. The model is then used to provide guidelines for optimization of the preform impregnation conditions for a given material configuration.
On the Margins of Beau Travail
Authors: Grant Ben
Published: July 2004

Placing myself on the margins ofBeau Travail and inspired by the montage technique used by Claire Denis, in this article I juxtapose scenes from the film with extracts from other texts to suggest an intertextual reading which explores the manner in which power and desire are articulated within a complex network of gazes. Beginning with the character of Bruno Forestier, whose gaze holds together the 13th Division of the French Foreign Legion, I move progressively outwards to consider in turn the structure of this division, the Africans observing it from its periphery, Galoup recalling his past, and finally the spectator on the margins of the film.
Women’s Preferences for Doctor’s Involvement in Decisions about Mammography Screening
Authors: Chamot Eric , Charvet Agathe , Perneger Thomas V.
Published: July 2004

Objectives. To assess women’s preferences for doctor’s involvement in mammography screening decisions. Methods. Mail survey of 50-to 69-year-old women residing in Geneva, Switzerland (N = 2216). Results. Women considered that the decision to undergo mammography screening should be made by thedoctor alone (5.6%), doctor primarily (42.6%),shared equally between woman and doctor (45.0%),woman primarily (4.2%), andwoman alone (2.4%). These subgroups differed considerably. Compared to women in theshared equally group,doctor alone respondents were more likely to be older, to be born outside Switzerland, and to wish to know as late as possible about having cancer. In contrast, woman alone respondents were more likely to report no previous mammogram, to expect bad news frommammograms, and to feel nervous about screening. Conclusions. Most women wished to see their doctor involved in the decision to undergo a screening mammogram. Nevertheless, notable minorities held other opinions.
Mechanical Properties of Date Palm Leaves
Authors: Al-Sulaiman Faleh
Published: July 2004

The basic mechanical properties of date palm leaves are investigated. This abundant and cheap fibrous material exhibits very favorable characteristics that can make it an excellent building block in composite structures. The tensile strength (210 MPa) and the specific strength (180 MPa cm3/g) of this fiber are higher than many common building materials (i.e., wood, aluminum and steel). The mechanical properties are dependent on the moisture content of the leaves and the temperature exposure.
Constant Amplitude Fatigue of Short Glass and Carbon Fiber Reinforced Thermoplastics
Authors: Zago Alessandro , Springer George S.
Published: July 2004

The fatigue lives (i.e., the number of cycles to failure) of short fiber reinforced thermoplastic matrix composites were investigated. First, S-N curves were generated at stress ratios of R = 0 and R = -1 for short glass fiber reinforced Copolyamide coupons with 0° (30% or 50% fiber content by weight), 45° (50% fiber content) and 90° (30% or 50% fiber content) fiber orientations. Second, these S-N curves were compared to data reported in the literature for a wide range of short glass and short carbon fiber reinforced thermoplastics materials. On the basis of these comparisons, all available data were “collapsed” on two S-N curves, one for R = 0 and one for R = -1.
Characterization of acute lymphoblastic leukemia progenitor cells
Authors: Cox Charlotte V. , Evely Roger S. , Oakhill Anthony , Pamphilon Derwood H. , Goulden Nicholas J. , Blair Allison
Published: July 2004

Only some acute lymphoblastic leukemia (ALL) cells are thought to be capable of proliferating to maintain the leukemic clone, and these cells may be the most relevant to target with treatment regimens. We have developed a serum-free suspension culture (SC) system that supported growth of B-ALL cells from 33 patients for up to 6 weeks. ALL cells from 28 cases (85%) were expanded in this system, and growth was superior in SC than in long-term bone marrow culture. To characterize ALL progenitors, cells were sorted for expression of CD34 and CD10 or CD19 and the subfractions assayed in SC and in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. Cells capable of long-term proliferation in vitro and NOD/SCID repopulation were derived only from the CD34+/CD10- and CD34+/CD19- subfractions, and these cells could engraft secondary recipients. The engrafted cells had the same immunophenotype and karyotype as was seen at diagnosis, suggesting they had differentiated in vivo. These results demonstrate that ALL cells capable of long-term proliferation in vitro and in vivo are CD34+/CD10-/CD19-. This suggests that cells with a more immature phenotype, rather than committed B-lymphoid cells, may be the targets for transformation in B-ALL.
The absence of Grb2-associated binder 2 (Gab2) does not disrupt NK cell development and functions
Authors: Zompi Simona , Gu Hahiua , Colucci Francesco
Published: July 2004

Scaffolding molecules bind simultaneously and link together various components of signal-transduction pathways. Grb2-associated binder 2 (Gab2) is a scaffolding protein required for FcγR-initiated allergic responses in mast cells and FcγR-mediated phagocytosis in macrophages, where it links IgE and IgG receptors to the phosphatidylinositol-3 kinase (PI-3K) pathway. The FcγR expressed by natural killer (NK) cells triggers antibody-dependent cellular cytotoxicity (ADCC). We show here that mouse NK cells express Gab2 and that although PI-3K was required for ADCC, this FcγR-mediated function was normal in Gab2−/− NK cells. Moreover, NK cell development, spontaneous cytotoxicity, and responses to and production of cytokines were not perturbed in Gab2−/− mice. Considering the striking differences between the signaling requirements of FcγR in macrophages and NK cells, our findings suggest that the organization of signal transduction downstream of the same FcR can be cell type-specific. Conversely, Gab family members Gab1, Gab2, and Gab3 may play specific roles in different leukocytes. As pharmacological targeting of Gab2 in mast cells is a potential strategy to treat allergy, our results suggest prudence, as NK cells may participate in IgE-mediated anaphylaxis in a Gab2-independent manner.
Development of intestinal inflammation in double IL-10- and leptin-deficient mice
Authors: Siegmund Britta , Sennello Joseph A , Lehr Hans A , Batra Arvind , Fedke Inka , Zeitz Martin , Fantuzzi Giamila
Published: July 2004

Leptin-deficient (ob/ob) mice are resistant in different models of autoimmunity and inflammation, suggesting that leptin regulates immunity and inflammation. To investigate whether leptin deficiency modulates the spontaneous intestinal inflammation observed in interleukin (IL)-10-deficient mice, double IL-10- and leptin-deficient [IL-10 knockout (KO) ob/ob] mice were generated and compared with single IL-10 KO mice for colitis severity. Body weight in IL-10 KO ob/ob mice was significantly reduced compared with that of ob/ob mice. However, when compared with wild-type or IL-10 KO mice, IL-10 KO ob/ob mice were still markedly obese. IL-10 KO and IL-10 KO ob/ob mice developed colitis with a comparable time-course and severity in terms of macroscopic and histologic scores. Likewise, production of inter feron-γ, IL-6, and IL-13 from colon cultures and splenocytes did not differ among these two groups. Conversely, rates of apoptosis were higher in lamina propria lymphocytes obtained from the colon of IL-10 KO ob/ob compared with IL-10 KO mice. In conclusion, although leptin deficiency has been associated with resistance in models of autoimmunity and inflammation induced by exogenous stimuli, leptin appears not to play a significant role in the spontaneous colitis of IL-10 KO mice, although it modulates survival of intestinal lymphocytes.
Dendritic cells derived from BCG-infected precursors induce Th2-like immune response
Authors: Martino Angelo , Sacchi Alessandra , Sanarico Nunzia , Spadaro Francesca , Ramoni Carlo , Ciaramella Antonio , Pucillo Leopoldo Paolo , Colizzi Vittorio , Vendetti Silvia
Published: July 2004

Human monocytes can differentiate into dendritic cells (DCs) according to the nature of environmental signals. We tested here whether the infection with the live tuberculosis vaccine bacillus Calmette-Guerin (BCG), which is known to be limited in preventing pulmonary tuberculosis, modulates monocyte and DC differentiation. We found that monocytes infected with BCG differentiate into CD1a– DCs (BCG-DCs) in the presence of granulocyte macrophage-colony stimulating factor and interleukin (IL)-4 and acquired a mature phenotype in the absence of maturation stimuli. In addition, BCG-DCs produced proinflammatory cytokines (tumor necrosis factor α, IL-1β, IL-6) and IL-10 but not IL-12. BCG-DCs were able to stimulate allogeneic T lymphocytes to a similar degree as DCs generated in the absence of infection. However, BCG-DCs induced IL-4 production when cocultured with human cord-blood mononuclear cells. The induction of IL-4 production by DCs generated by BCG-infected monocytes could explain the failure of the BCG vaccine to prevent pulmonary tuberculosis.
Chemokine expression during the development and resolution of a pulmonary leukocyte response to influenza A virus infection in mice
Authors: Wareing Mark D , Lyon Ashley B , Lu Bao , Gerard Craig , Sarawar Sally R
Published: July 2004

Influenza A virus replicates in the respiratory epithelium and induces an inflammatory infiltrate comprised of mononuclear cells and neutrophils. To understand the development of the cell-mediated immune response to influenza and how leukocyte trafficking to sites of inflammation is regulated, we examined the chemokine expression pattern in lung tissue from A/PR/8/34-infected C57BL/6 mice using an RNase protection assay. Monocyte chemoattractant protein 1, macrophage inflammatory protein 1α (MIP-1α), MIP-1β, MIP-3α, regulated on activation, normal T expressed and secreted (RANTES), MIP-2, and interferon-inducible protein 10 (IP-10) mRNA expression was up-regulated between days 5 and 15 after infection, consistent with a role for these chemokines in leukocyte recruitment to the lung. Low levels of expression were detected for the CC chemokine receptors (CCR)2 and CCR5, whereas CXC chemokine receptor (CXCR)3 was significantly up-regulated by day 10 after infection, coinciding with peak inflammatory cell infiltration in the airways. As RANTES, IP-10, and their receptors were up-regulated during influenza virus infection, we investigated leukocyte recruitment and viral clearance in mice deficient in RANTES or CXCR3, the receptor for IP-10. Leukocyte recruitment and viral replication in influenza-infected RANTES knockout(−/−) mice were similar to that in control mice, showing that RANTES is not essential for the immune response to influenza infection. Similarly, leukocyte recruitment and viral replication in CXCR3−/− mice were identical to control mice, except at day 8 postinfection, where fewer lymphocytes, neutrophils, and eosinophils were detected in the bronchoalveolar lavage of CXCR3−/− mice. These studies suggest that although the chemokines detected may play a role in regulating leukocyte trafficking to the lung during influenza infection, some may be functionally redundant.
KNUCKLES(KNU) encodes a C2H2 zinc-finger protein that regulates development of basal pattern elements of the Arabidopsis gynoecium
Authors: Payne Thomas , Johnson Susan D. , Koltunow Anna M.
Published: July 2004

Flowers of the parthenocarpic knuckles mutant are conditionally male sterile and contain ectopic stamens and carpels that originate from placental tissue within developing gynoecia. The mutation was mapped to a 123 Kb interval on chromosome 5 using molecular markers. All aspects of the knuckles phenotype could be complemented by a genomic fragment from the region which contained the annotated MAC12.2 gene. A guanine to adenine transition within a predicted C2H2 zinc finger-encoding region of MAC12.2 causes the second of two critical zinc-binding cysteine residues to be replaced by a tyrosine. Transgenic plants in which translational fusions of the GUS reporter to KNUCKLES were driven by the presumptive KNUCKLES promoter indicate that the gene is expressed first in developing carpel primordia, and later in stamens and ovules of flower buds. In situ hybridization experiments showed a broader pattern of transcript localization, suggesting that post-transcriptional regulatory mechanisms may limit KNUCKLES protein accumulation and localization. Based on genetic evidence and the presence of a carboxy-terminal motif demonstrated by others to function as an active repression domain, we propose that KNUCKLES might function as a transcriptional repressor of cellular proliferation that regulates floral determinacy and relative size of basal pattern elements along the proximo-distal axis of the developing Arabidopsis gynoecium.
Combinatorial gene regulation by Bmp and Wnt in zebrafish posterior mesoderm formation
Authors: Szeto Daniel P. , Kimelman David
Published: July 2004

Combinatorial signaling is an important mechanism that allows the embryo to utilize overlapping signaling pathways to specify different territories. In zebrafish, the Wnt and Bmp pathways interact to regulate the formation of the posterior body. In order to understand how this works mechanistically, we have identified tbx6 as a posterior mesodermal gene activated by both of these signaling pathways. We isolated a genomic fragment from the tbx6 gene that recapitulates the endogenous tbx6 expression,and used this to ask how the Bmp and Wnt signaling pathways combine to regulate gene expression. We find that the tbx6 promoter utilizes distinct domains to integrate the signaling inputs from each pathway,including multiple Tcf/LEF sites and a novel Bmp-response element. Surprisingly, we found that overexpression of either signaling pathway can activate the tbx6 promoter and the endogenous gene, whereas inputs from both pathways are required for the normal pattern of expression. These results demonstrate that both Bmp and Wnt are present at submaximal levels,which allows the pathways to function combinatorially. We present a model in which overlapping Wnt and Bmp signals in the ventrolateral region activate the expression of tbx6 and other posterior mesodermal genes, leading to the formation of posterior structures.
The oxidation of uranium(IV) ions by nitrous acid in 30% tri-butyl phosphate
Authors: Koltunov V. S. , Taylor Robin J. , Marchenko V. I. , Savilova O. A. , Dvoeglazov K. N.
Published: July 2004

The kinetics of the oxidation of U(IV) ions by nitrous acid in a 30% TBP solution have been determined. The rate equation was found to be:

-d[U(IV)]/dt=k2a([U(IV)][HNO2][HNO3][H2O])/([HNO3]2+β3[HNO3][H2O]+β4[H2O]2),

where,k2a=0.405±0.055 M-1min-1at 55 °C (β3≈0.08;β4≈0.007) and the activation energy wasE=112±17 kJ mol-1. The reaction mechanism appeared to involve interaction with the 1sthydrolysis product of U(IV)–UOH3+. The data is compared with a previous study of the nitric acid oxidation of U(IV) in 30% TBP. This reaction is autocatalytic due to the formation of nitrous acid during the reaction. The kinetics of the decomposition of HNO2in 30% TBP (in the absence of U(IV)) have also been reported.
Anion-exchange behavior of Mo and W as homologs of Sg (element 106) in HCl and HNO3 as well as in mixed HCl-HF and HNO3-HF solutions
Authors: Kronenberg A. , Mohapatra P. K. , Kratz Jens Volker , Pfrepper G. , Pfrepper R.
Published: July 2004

We have determined K
d values for Mo and W in batch experiments on various anion-exchange resins in HCl and HNO3 as well as in mixed HCl-HF and HNO3-HF solutions in order to create a data base and to select optimum conditions for the determination of K
d values of Sg (element 106) in a future on-line experiment using continuous chromatography with the multi-column technique (MCT). Their influence by hydrolysis and fluoride complexation is discussed and the average charge of the complexes is determined from slope analyses. It is shown that the selectivity of anion exchangers for the Mo- and W complexes and, thus, the separation factors between them, depend strongly on the choice of the functional group of the anion-exchange resin.
Determination of trace element concentration in infant head hair of Rawalpindi/Islamabad area using INAA technique
Authors: Zaidi Jamshed H. , Gill K. P.
Published: July 2004

The concentration of 18 minor and trace elements (essential, toxic and nonessential) in infant head hair was determined. The data provide the base-line values of these elements in head hair of infants of low- and medium-income group subjects. The statistical results show that there are significant correlations between some elements such as: Ca-Zn, Ca-Fe, Mg-Ca, Mg-Mn and Mg-Fe. The results obtained have been compared with the data reported in the literature. Our data show compatibility of elemental contents of infant head hair with those from some of the other geological regions but also deviate in some cases.
Habitat Use by Middle Mississippi River Pallid Sturgeon
Authors: Hurley Keith L. , Sheehan Robert J. , Heidinger Roy C. , Wills Paul S. , Clevenstine Bob
Published: July 2004

Little is known about the habitat preferences and needs of pallid sturgeon Scaphirhynchus albus, which was federally listed as endangered in 1990. To learn more about habitat use and selection by pallid sturgeon, sonic transmitters were surgically implanted in 27 individuals from the middle Mississippi River. Study fish were located 184 times (1–23 times/individual) from November 1995 to December 1999. Of the seven macrohabitats identified, pallid sturgeon were found most often in main‐channel habitats (39% of all relocations) and main‐channel border habitats (26%); the between‐wing‐dam habitats were used less often (14%). Strauss's linear selectivity index (Li) values indicated that study fish exhibited positive selection for the main‐channel border, downstream island tips, between‐wing‐dam, and wing‐dam‐tip habitats; they showed negative selection for main‐channel, downstream of wing dams, and upstream of wing dam habitats. Comparison of Li values for four temperature ranges and three daily mean discharge ranges revealed little change in habitat selection due to temperature or discharge. Habitat use patterns also were similar across seasons and discharge regimes, except during spring months when between‐wing‐dam habitats saw greater use and main‐channel and main‐channel border habitat use declined. These changes may have been a response to high river stages associated with spring flooding, which may create favorable feeding areas in the between‐wing‐dam habitats. Enhancement and restoration of habitat diversity, particularly downstream island tip and between‐wing‐dam habitats, may be necessary for the recovery of pallid sturgeon in the middle Mississippi River.
Fundamentgestaltung und Sohlspannungsberechnung mit Optimierungsmethoden und Tabellenkalkulation
Authors: Mark Peter
Published: July 2004

Es werden Optimierungsaufgaben aus den Gleichgewichtsbeziehungen zwischen einwirkenden Schnittgrößen und widerstehenden Sohlspannungen sowie Geometrie‐ und Spannungsrandbedingungen formuliert, um Fundamentflächen in Abhängigkeit von gegebenen Einwirkungen und veränderbaren Geometriefreiwerten bestmöglich in Form, Größe und Lage einzustellen. Die Optimierungsaufgaben werden mit praxisüblichen Tabellenkalkulationsprogrammen unter Verwendung numerischer Optimierungsverfahren und numerischer Integration der innerhalb der Gleichgewichtsbeziehungen enthaltenen Flächenintegrale gelöst. Ein Beispiel zeigt die praktische Anwendung.
Comparison of Fixed and Fluidized Activated Carbon Beds for Removal of Organic Vapors
Authors: Agranovski I.E. , Moustafa S. , Braddock R.D.
Published: July 2004

Activated carbons are commonly used for removal of organic vapors from exhaust air streams. Two configurations, including fixed and fluidized carbon beds are usually employed in industry to meet various requirements of the industrial process which is being used. This paper investigates the performance of such configurations and provides a comparative analysis. It was found that for thin carbon layers, the fixed bed performs more efficiently with the difference exceeding 15 % for the layers with the thickness less than 15 mm. This difference is decreasing with increase of the layer thickness and becomes less than 5 % for the beds thicker than 100 mm. Considering various advantages of the fluidized beds over fixed beds, including lower resistance to the gas flow, excellent gas distribution and minimal possibility of clogging in case of existence of alien particles in the gas, they are recommended for use with the minimal thickness of the layer to be larger than 100 mm.
Determination of Crystal Growth Kinetics Using Ultrasonic Technique
Authors: Glade H. , Ilyaskarov A.M. , Ulrich J.
Published: July 2004

The ultrasonic measurement technique was proven to be an accurate, reproducible, fast, and easy to use technique for the determination of crystal growth kinetics. Desupersaturation curves of various solutions of inorganic and organic substances, e.g., copper sulphate pentahydrate (CuSO4 · 5 H2O) and potash alum (KAl(SO4)2 · 12 H2O), were measured in seeded isothermal batch crystallization experiments.
Mixing of Fine Grained Particles with Electrostatic Support
Authors: Wirth K.‐E. , Linsenbühler M.
Published: July 2004

When handling of finest grained particles van der Waals adhesion force and electrostatic force control the behavior of the particles, which leads to caking, agglomeration and a reduced flowability. Coating with nano‐particles helps reducing their mutual attraction forces, because they act as spacer. In the present work it is shown that the electrostatically supported mixing can be carried out in liquid media, which decreases the affinity for agglomeration and simplifies the mixing process. Applicative suspension media are non‐conducting liquids notably liquid nitrogen.
Investigations about Bulk Solids with Silo Centrifuge Testing
Authors: Großstück M. , Schwedes J.
Published: July 2004

The influence of relaxation and creep for silo design and prediction of a reasonable and reliable outlet dimension for trouble‐free flow of bulk solids are presented. The use of silo centrifuge testing was chosen to reduce the model silo size and to decrease the needed amount of bulk solids. Experiments with limestone of 25 μm particle size showed good agreement between silo centrifuge testing and silo design according to Jenike method. The creeping effects could successfully demonstrated with moist gypsum with the silo centrifuge technique.
Cover Picture: Tetrahedral Chalcogenide Clusters and Open Frameworks (Chem. Eur. J. 14/2004)
Authors: Bu Xianhui , Zheng Nanfeng , Feng Pingyun
Published: July 2004

The cover picture shows a zeolite‐like three‐dimensional metal–sulphide network, the pore opening of which is highlighted with the polyhedral representation of eight interconnected adamantane‐like clusters. At the center is the largest known supertetrahedral cluster containing thirty‐five cationic metal sites and fifty‐six anionic chalcogen sites. More details can be found in the article by P. Feng, X. Bu, and N. Zheng on p. 3356 ff.
Stereochemical Determination of Dictyostatin, a Novel Microtubule‐Stabilizing Macrolide from the Marine Sponge Corallistidae sp.
Authors: Paterson Ian , Britton Robert , Delgado Oscar , Wright Amy E.
Published: July 2004

For Abstract see ChemInform Abstract in Full Text.
Solubility of Solids and Liquids in Supercritical Fluids
Authors: Aim Karel , Fermeglia Maurizio
Published: July 2004

For Abstract see ChemInform Abstract in Full Text.
Pyrolysis of Biomass to Produce Fuels and Chemical Feedstocks
Authors: Yaman Serdar
Published: July 2004

For Abstract see ChemInform Abstract in Full Text.
Antioxidant properties of polyphenol‐containing extract from soybean fermented with Saccharomyces cerevisiae
Authors: Romero Ana M. , Doval Mirtha M. , Sturla Mario A. , Judis Maria A.
Published: July 2004

The antioxidant properties and total phenolic compounds of soybean extract fermented with Saccharomyces cerevisiae during 24 h were evaluated. Total polyphenolic compounds extracted in ethanol/water (1:1) solution were 789.54 mg/g dry extract, and flavonoids were 169.47 mg quercetin equivalents/g of dry extract. Reducing power (91.18%) and DPPH scavenging (79.30% at 4‐times diluted) were excellent, and so high as BHA, 92.17% and 73.8% respectively, while superoxide anion scavenging showed poor inhibition (4876 equivalent SOD U/g). Antioxidant activity in linoleic acid/water emulsion system of fermented extract measured as peroxide formation inhibition at 37 °C was the strongest (95.62%), while it exerted a moderate inhibition for conjugated dienes and thiobarbituric acid reactive substances (64.77% and 54.33%). At 80 °C the antioxidant activity assayed at a higher concentration was less effective (29.35% on CD; 74.58% on PV and 35.04% on TBARS).
Fourth‐order accurate compact‐difference discretization method for Helmholtz and incompressible Navier–Stokes equations
Authors: Steijl R. , Hoeijmakers H. W. M.
Published: July 2004

A fourth‐order accurate solution method for the three‐dimensional Helmholtz equations is described that is based on a compact finite‐difference stencil for the Laplace operator. Similar discretization methods for the Poisson equation have been presented by various researchers for Dirichlet boundary conditions. Here, the complicated issue of imposing Neumann boundary conditions is described in detail. The method is then applied to model Helmholtz problems to verify the accuracy of the discretization method. The implementation of the solution method is also described. The Helmholtz solver is used as the basis for a fourth‐order accurate solver for the incompressible Navier–Stokes equations. Numerical results obtained with this Navier–Stokes solver for the temporal evolution of a three‐dimensional instability in a counter‐rotating vortex pair are discussed. The time‐accurate Navier–Stokes simulations show the resolving properties of the developed discretization method and the correct prediction of the initial growth rate of the three‐dimensional instability in the vortex pair. Copyright © 2004 John Wiley & Sons, Ltd.
Glial modulation of synaptic transmission in culture
Authors: Araque Alfonso , Perea Gertrudis
Published: July 2004

Accumulating evidence has demonstrated the existence of bidirectional communication between glial cells and neurons, indicating an important active role of glia in the physiology of the nervous system. Neurotransmitters released by presynaptic terminals during synaptic activity increase intracellular Ca2+ concentration in adjacent glial cells. In turn, activated glia may release different transmitters that can feed back to neuronal synaptic elements, regulating the postsynaptic neuronal excitability and modulating neurotransmitter release from presynaptic terminals. As a consequence of this evidence, a new concept of the synaptic physiology, the tripartite synapse, has been proposed, in which glial cells play an active role as dynamic regulatory elements in neurotransmission. In the present article we review evidence showing the ability of astrocytes to modulate synaptic transmission directly, with the focus on studies performed on cell culture preparations, which have been proved extremely useful in the characterization of molecular and cellular processes involved in astrocyte‐mediated neuromodulation. © 2004 Wiley‐Liss, Inc.
Glial modulation of synaptic transmission: Insights from the supraoptic nucleus of the hypothalamus
Authors: Oliet Stéphane H.R. , Piet Richard , Poulain Dominique A. , Theodosis Dionysia T.
Published: July 2004

Astrocytes clear synaptically released glutamate from the extracellular space through high‐affinity transporters present on their plasma membrane. By controlling the extracellular level of the main excitatory transmitter in the central nervous system, astrocytes thus contribute prominently to the regulation of overall cellular excitability and synaptic information processing. We recently investigated the influence of the glial environment on glutamatergic and GABAergic neurotransmission in the supraoptic nucleus of the rat hypothalamus under physiological conditions such as lactation that significantly reduce astrocytic coverage of its neurons. By performing electrophysiological analyses on this unique model of dynamic neuronal‐glial interactions, we have been able to show that the fine astrocytic processes normally enwrapping synapses serve two important functions. First, they govern the level of activation of presynaptic metabotropic glutamate receptors on glutamatergic terminals, thereby regulating synaptic efficacy at excitatory synapses. Second, they act as a physical and functional barrier to diffusion in the extracellular space, limiting spillover of glutamate and other neuroactive substances and therefore contributing to the regulation of heterosynaptic transmission and intercellular communication. © 2004 Wiley‐Liss, Inc.
Glial modulation of synaptic transmission in the hippocampus
Authors: Volterra Andrea , Steinhäuser Christian
Published: July 2004

For many years, astrocytes and oligodendrocytes were considered the inert partners of neurons in the central nervous system (CNS), but several recent studies have dramatically challenged this view. Glial cells express a large number of different voltage‐ and ligand‐gated ion channels (Verkhratsky and Steinhäuser. Brain Res Rev 32:380–412, 2000) as well as G‐protein‐coupled receptors (Verkhratsky et al. Physiol Rev 78:99–141, 1998)—machinery necessary to sense and respond to neuronal activity. These findings raised the fundamental question as to whether glial receptors are stimulated under physiological conditions, and what sorts of events are triggered by such activation. During the early 1990s, P. Haydon and colleagues made the seminal observation that [Ca2+]i rises in cultured astrocytes are associated with the release of glutamate, which suggested that astrocytes respond to activation and play active modulatory roles in intercellular communication (Parpura et al. Nature 369:744–747, 1994). Subsequent studies performed in situ confirmed and extended this initial observation. In this review, we will focus specifically on the hippocampus and sum up evidence of bidirectional communication between astrocytes and neurons emerging from recent studies using acute slice preparations. © 2004 Wiley‐Liss, Inc.
Role for glia in synaptogenesis
Authors: Ullian Erik M. , Christopherson Karen S. , Barres Ben A.
Published: July 2004

Nearly one‐half of the cells in a human brain are astrocytes, but the function of these little cells remains a great mystery. Astrocytes form an intimate association with synapses throughout the adult CNS, where they help regulate ion and neurotransmitter concentrations. Recent in vitro studies, however, have found that astrocytes also exert powerful control over the number of CNS synapses that form, are essential for postsynaptic function, and are required for synaptic stability and maintenance. Moreover, recent studies increasingly implicate astrocytes in vivo as participants in activity‐dependent structural and functional synaptic changes throughout the nervous system. Taken together, these data force us to rethink the role of glia. We propose that astrocytes should not be viewed primarily as support cells, but rather as cells that actively control the structural and functional plasticity of synapses in developing and adult organisms. © 2004 Wiley‐Liss, Inc.
The prevalence of depressive symptoms among elderly Chinese private nursing home residents in Hong Kong
Authors: Lun Chow Eddie Siu , Hei Kong Bernard Ming , Po Wong Mike Tak , Draper Brian , Lin Ka Leung , Sabrina Ho Shuk Kuen , Por Wong Chun
Published: July 2004

Background

Privately‐owned Nursing homes (PNH) in Hong Kong present a unique setting of institutional care where elderly with the whole spectrum of health status live together.

Objectives

This cross‐sectional descriptive study aimed to determine the prevalence of significant depressive symptoms in a group of Cantonese‐speaking Chinese private nursing home elderly living in Hong Kong, and to identify associated psychosocial and health factors.

Methodological Results

Two hundred and forty five residents fulfilled the inclusion criteria. Using the Chinese version of the Geriatric Depression Scale—Short Form (GDS‐SF), we detected significant depressive symptoms in 29% of subjects. Univariate analysis revealed some associated socio‐economic risk factors including current non‐Comprehensive Social Security Assistance (CSSA) recipients, education levels and low abilities for social activities. Low vision, swallowing difficulties and low levels of basic activities of daily living (BADL) as reflected by the total Modified Barthel Index of less than 61 were important health predictors. Depression was also associated with features of self‐perception of financial inadequacy, life dissatisfaction, poor self‐perceived health, poor attitudes towards living arrangement and suicidal thoughts. Stepwise logistic regression identified swallowing problems, current non‐CSSA recipient and low BADL ability as independent risk factors.

Conclusion

The high prevalence of depressive symptoms in the nursing home elderly requires the attention of Government authorities, health care and social service providers. Copyright © 2004 John Wiley & Sons, Ltd.