bluuebunny/crossref_metadata_2025_split huggingface dataset:
Site‐specific recombination in human cells catalyzed by the wild‐type integrase protein of coliphage HK022
Authors: Kolot Mikhail , Meroz Adi , Yagil Ezra 
Published: August 2003

AbstractThe activity of the Integrase (Int) protein encoded by coliphage HK022 was tested in a human cell culture. Plasmids were constructed as substrates that carry the sites of the integration reaction (attP and attB) or the sites of excision (attL and attR). The site‐specific recombination reactions were monitored in cis and in trans configurations by the expression of the green fluorescent protein (GFP) as a reporter. Cells cotransfected with the substrate plasmid(s) and with a plasmid that expresses the wild‐type Int show efficient integration as well as excision in both configurations. The wild‐type Int was active in the human cells without the need to supply the accessory proteins integration host factor (IHF) and excisionase (Xis) that are indispensable for the reaction in the bacterial host. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 56–60, 2003.
Production of recombinant proteins using multiple‐copy gene integration in high‐cell‐density fermentations of Ralstonia eutropha
Authors: Srinivasan Sriram , Barnard Gavin C. , Gerngross Tillman U. 
Published: August 2003

AbstractWe have previously reported the development of a novel protein expression system based on Ralstonia eutropha. In this study we report on the influence of gene copynumber on recombinant protein expression in R. eutropha. We compare recombinant gene stability and expression levels of chromosomal integration with a plasmid‐based expression system. Single, double, and triple copies of a gene encoding organophosphohydrolase (OPH), an enzyme prone to inclusion‐body formation in E. coli, were integrated into the R. eutropha chromosome. A linear increase between the concentration of soluble, active OPH and gene copynumber was found. Using a triple‐copy integrant, we were able to produce approximately 4.3 g/L of OPH in a high‐cell‐density fermentation. This represents the highest titer reported to date for this enzyme, and is approximately 30 times greater than expression levels reported in E. coli. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 114–120, 2003.
Neandertals, competition, and the origin of modern human behavior in the Levant
Authors: Shea John J. 
Published: August 2003

AbstractThe East Mediterranean Levant is a small region, but its paleoanthropological record looms large in debates about the origin of modern humans and the fate of the Neandertals. For most of the twentieth century, the Levantine paleoanthropological record supported models of continuity and evolutionary transition between Neandertals and early modern humans. Recent advances in radiometric dating have challenged these models by reversing the chronological relationship between Levantine Neandertals and early modern humans. This revised chronostratigraphy for Levantine Middle Paleolithic human fossils raises interesting questions about the evolutionary relationship between Neandertals and early modern humans. A reconsideration of this relationship moves us closer to understanding the long delay between the origin of morphologically modern‐looking humans during the Middle Paleolithic (>130 Kyr) and the adaptive radiation of modern humans into Eurasia around the time of the transition from the Middle to Upper Paleolithic (50 to 30 Kyr).
Governance in a period of strategic change in U.S. healthcare
Authors: Weil Thomas P. 
Published: August 2003

AbstractThe increased enrollment in managed care plans, merger mania and the development of politically and financially powerful integrated delivery systems have significantly complicated the governance of U.S. healthcare organizations. These modifications in fiscal incentives and the corporate restructuring undertaken by American health organizations has resulted in limited fiscal savings or improvements in access to care. As a result, trustees are now faced with divesting their losers, and shuttering facilities and services to reduce fixed costs. Decision‐making by trustees will be further thwarted in the future by: their institutions being forced to deliver more care without a proportional increase in revenues; physicians seeking to obtain more ambulatory revenues at a hospital's expense; the inability to adequately finance mental health and long‐term care services except among the wealthy; the number of divestitures increasing so that eventually the organizational focus for most IDSs will once again be on regionally oriented hospital systems; and much more difficulty being experienced in attracting sufficiently qualified personnel to deliver high quality health services. Finally, many of these findings relevant to the United States also are being shared by governing boards in Canada, Germany, The Netherlands and the United Kingdom. Copyright © 2003 John Wiley & Sons, Ltd.
Assessment of the quantitative and qualitative buffer function of an alluvial wetland: hydrological modelling of a large floodplain (Garonne River, France)
Authors: Weng P. , Sánchez‐Pérez J. M. , Sauvage S. , Vervier P. , Giraud F. 
Published: August 2003

AbstractFor 2 years, water flow‐patterns in the Garonne floodplain of south‐western France were studied in the field and through hydrodynamic modelling (MARTHE Hydrodynamic Software developed by BRGM). Water flow‐paths and the transport of dissolved elements between river and aquifer have been investigated and modelled. In order to quantify the buffer function of the alluvial floodplain, we focused our work on the effect of a major flood on the water flow‐direction, and on nitrate transport. Thus, we showed that the effect of a large flood in the river was rapidly lost with increasing distance from the river. During the observation period, a hydrologically active strip only 300 m wide on either side of the riverbed played a buffering role in absorbing the flood crest. It was also found that meanders favour the exchange between river and alluvial aquifer, shown by the creation of bypasses between the upstream and downstream parts of meanders. This, in turn, contributes to a dilution of nitrates in the phreatic aquifer, which here has higher nitrate content than the surface water; such dilution may result in an overestimation of the denitrification process in the wooded riverbanks. The coupling of chemical measurements—especially of chlorides and nitrate—with modelling of the dissolved‐element transport allows us to establish the water balance for the riparian wetland, and to separate the effect of dilution and denitrification on nitrate concentration. This indicated the existence of areas in the riparian wetlands where denitrification is particularly strong, leading to reductions in nitrate concentrations of 10 to 30 mg/l NO3− during the flood. Copyright © 2003 John Wiley & Sons, Ltd.
Using a low‐voltage intermodulation distortion sweet‐spot for controlling gain in HEMT amplifiers
Authors: Malaver Emigdio , García José Ángel , Tazón Antonio , Mediavilla Angel 
Published: August 2003

AbstractIn this paper, a low‐voltage high‐linearity sweet‐spot, associated with an adjustable transconductance, is proposed for implementing a simple and highly linear HEMT‐based gain control strategy. The proposed approach, based on a selective gate and drain biasing technique, is compared with the conventional solution under two‐tone and multitone excitations. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 67–70, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11129
Spectral study of a new dihydroisocoumarin
Authors: Wang H. M. , Shi W. , Xu Y. K. , Liu Y. , Lü M. J. , Pan J. Q. 
Published: August 2003

AbstractA novel dihydroisocoumarin, 3,4‐dihydro‐6,8‐dihydroxy‐3‐(2′‐acetyl‐3′‐hydroxy‐5′‐methoxy)methyl‐1H‐[2]benzopyran‐1‐one, was isolated from the chloroform extract of the sap of the traditional herb Aloe vera. Its structure was determined by high‐resolution negative fast atom bombardment mass spectrometry (MS), 2D NMR spectroscopy and x‐ray crystallography. The molecular structure was elucidated by 2D NMR analysis. The complete assignment of the 1H and 13C NMR spectra of this compound was performed by using 1H detected one‐bond heteronuclear multiple quantum correlation (HMQC) and long‐range (two and three bonds) heteronuclear multiple quantum bond correlation (HMBC) experiments. Detailed analyses of the one‐ and two‐dimensional NMR techniques are presented in additional to the spectral properties (MS, IR and UV). Copyright © 2003 John Wiley & Sons, Ltd.
1H and 13C NMR assignments of abietane diterpenes from Aegiphila lhotzkyana
Authors: Pinheiro Barros Maria Claudia , Sousa Lima Mary Anne , Braz‐Filho Raimundo , Rocha Silveira Edilberto 
Published: August 2003

AbstractAn NMR study of one new and several known abietane diterpenes isolated from the roots of Aegiphila lhotzkyana is described. In addition to 1D NMR, several 2D shift‐correlated NMR pulse sequences (1H–1H‐COSY, NOESY, HMQC and HMBC) were used to establish all the structures, and unambiguously perform the 1H and 13C chemical shift assignments of the new natural diterpene and three derivatives, the NMR data for which have not been reported previously. Revision of current data assignment for teuvincenone H is also suggested. Copyright © 2003 John Wiley & Sons, Ltd.
Congenital pulmonary capillary hemangiomatosis: Report of two cases and review of the literature
Authors: Oviedo Angelica , Abramson Lisa P. , Worthington Ross , Dainauskas John R. , Crawford Susan E. 
Published: August 2003

AbstractPulmonary capillary hemangiomatosis (PCH) is a rare disease characterized by pulmonary hypertension and excessive neovascularization within the pulmonary interstitium, vasculature, and airways. We describe two unusual cases of congenital PCH. Both cases had concurrent anomalies, including renal and urinary bladder agenesis and hypertropic cardiomyopathy. In one case, capillary proliferation caused significant impingement of the proximal bronchial airways. A review of the current literature is described. Pediatr Pulmonol. 2003; 36:253–256. © 2003 Wiley‐Liss, Inc.
Identification of functionally conserved residues with the use of entropy–variability plots
Authors: Oliveira Laerte , Paiva Paulo B. , Paiva Antonio C.M. , Vriend Gerrit 
Published: August 2003

AbstractWe introduce sequence entropy–variability plots as a method of analyzing families of protein sequences, and demonstrate this for three well‐known sequence families: globins, ras‐like proteins, and serine‐proteases. The location of an aligned residue position in the entropy–variability plot correlates with structural characteristics, and with known facts about the roles of individual amino acids in the function of these proteins. The large numbers of known sequences in these families allowed us to introduce new filtering methods for variability patterns. The results are discussed in terms of a simple evolutionary model for functional proteins. Proteins 2003;52:544–552. © 2003 Wiley‐Liss, Inc.
Overexpression of a stress‐inducible aldehyde dehydrogenase gene from Arabidopsis thaliana in transgenic plants improves stress tolerance
Authors: Sunkar Ramanjulu , Bartels Dorothea , Kirch Hans‐Hubert 
Published: August 2003

SummaryIn plants, oxidative stress is one of the major causes of damage as a result of various environmental stresses. Oxidative stress is primarily because of the excessive accumulation of reactive oxygen species (ROS). The amplification of ROS damage is further stimulated by the accumulation of toxic degradation products, i.e. aldehydes, arising from reactions of ROS with lipids and proteins. Previously, the isolation of dehydration‐inducible genes encoding aldehyde dehydrogenases (ALDHs) was reported from the desiccation‐tolerant plant Craterostigma plantagineum and Arabidopsis thaliana. ALDHs belong to a family of NAD(P)+‐dependent enzymes with a broad substrate specificity that catalyze the oxidation of various toxic aldehydes to carboxylic acids. Analysis of transcript accumulation revealed that Ath‐ALDH3 is induced in response to NaCl, heavy metals (Cu2+ and Cd2+), and chemicals that induce oxidative stress (methyl viologen (MV) and H2O2). To investigate the physiological role and possible involvement of ALDHs in stress protection, we generated transgenic Arabidopsis plants overexpressing Ath‐ALDH3. Transgenic lines show improved tolerance when exposed to dehydration, NaCl, heavy metals (Cu2+ and Cd2+), MV, and H2O2. Tolerance of transgenic plants is correlated with decreased accumulation of lipid peroxidation‐derived reactive aldehydes (as measured by malondialdehyde) compared to wild‐type plants. Increased activity of Ath‐ALDH3 appears to constitute a detoxification mechanism that limits aldehyde accumulation and oxidative stress, thus revealing a novel pathway of detoxification in plants. We suggest that Ath‐ALDH3 could be used to obtain plants with tolerance to diverse environmental stresses.
Thermally induced conformational changes in horseradish peroxidase
Authors: Pina David G. , Shnyrova Anna V. , Gavilanes Francisco , Rodríguez Anabel , Leal Fernando , Roig Manuel G. , Sakharov Ivan Y. , Zhadan Galina G. , Villar Enrique , Shnyrov Valery L. 
Published: August 2003

Detailed differential scanning calorimetry (DSC), steady‐state tryptophan fluorescence and far‐UV and visible CD studies, together with enzymatic assays, were carried out to monitor the thermal denaturation of horseradish peroxidase isoenzyme c (HRPc) at pH 3.0. The spectral parameters were complementary to the highly sensitive but integral method of DSC. Thus, changes in far‐UV CD corresponded to changes in the overall secondary structure of the enzyme, while that in the Soret region, as well as changes in intrinsic tryptophan fluorescence emission, corresponded to changes in the tertiary structure of the enzyme. The results, supported by data about changes in enzymatic activity with temperature, show that thermally induced transitions for peroxidase are irreversible and strongly dependent upon the scan rate, suggesting that denaturation is under kinetic control. It is shown that the process of HRPc denaturation can be interpreted with sufficient accuracy in terms of the simple kinetic scheme
image

where k is a first‐order kinetic constant that changes with temperature, as given by the Arrhenius equation; N is the native state, and D is the denatured state. On the basis of this model, the parameters of the Arrhenius equation were calculated.
Some reflections on double fertilization, from its discovery to the present
Authors: Raghavan V. 
Published: August 2003

SummaryThe fusion of one sperm with the egg cell to form the embryo and of the other sperm with the polar fusion nucleus to give rise to the endosperm (‘double fertilization’) was discovered by Nawaschin in 1898 in the liliaceous plants, Lilium martagon and Fritillaria tenella. The occurrence of two fusion events analogous to double fertilization has recently been described in some gymnosperm species although the product of the second fusion is a transient embryo, rather than the endosperm as in angiosperms. Recent investigations in angiosperms describe the cell biology and nuclear cytology of double fertilization and the successful in vitro demonstration of the two fusion events using isolated egg cells, central cells, and sperm cells and the development of the fusion products into the embryo and endosperm. Molecular and genetic studies on the component elements of double fertilization have focused on the identification of mutants of Arabidopsis thaliana that display developmental patterns in the seed that result in autonomous endosperm development and even partial embryogenesis in the absence of fertilization. Characterization of the genes and their protein products has provided evidence for a predominant effect of maternal gametophytic genes and of silencing of paternal genes during double fertilization.

Contents

Summary
565

I.
Introduction
566

II.
Discovery of double fertilization
566

III.
Seed development without double fertilization
568

IV.
A case for double fertilization in gymnosperms
570

V.
Structural and cytological perspectives on double fertilization
571

VI.
In vitro double fertilization
575

VII.
Genetic and molecular perspectives
576

VIII.
Concluding comments
578

Acknowledgements
579

References
579
Antimicrobial Susceptibilities of
Salmonella
Strains Isolated from Humans, Cattle, Pigs, and Chickens in The Netherlands from 1984 to 2001
Authors: van Duijkeren E. , Wannet W. J. B. , Houwers D. J. , van Pelt W. 
Published: August 2003

ABSTRACT

We monitored antimicrobial susceptibility data for
Salmonella
strains isolated from humans, cattle, pigs, and chickens in The Netherlands from 1984 to 2001 in order to provide insight into the dynamics of resistance over time. The strains were tested for their susceptibilities to seven antimicrobial agents by the agar diffusion method. Resistance was most common in
Salmonella enterica
subsp
. enterica
serovar Typhimurium. Among the strains from humans, pigs, and chickens, it was found that the level of resistance of serovar Typhimurium strains to tetracycline, ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole increased from 1984 to 2001. This increase could be attributed to the emergence of multidrug-resistant serovar Typhimurium DT 104. Among the strains from cattle, it was found that the level of resistance of serovar Typhimurium strains, which was already very high in the 1980s, declined during the study period to the same levels as those for the strains from the other species from 1996 to 2001. Serovar Enteritidis isolates remained susceptible during the entire survey period. Among serovar Paratyphi B variation Java strains isolated from chickens, resistance to furazolidone, flumequine, trimethoprim-sulfamethoxazole, and ampicillin emerged, although furazolidone was not used after 1990. Together, the data indicate that the levels and patterns of resistance differed considerably between
Salmonella
serovars isolated from one host species.
Detection of
Chlamydia trachomatis
and
Neisseria gonorrhoeae
by Strand Displacement Amplification and Relevance of the Amplification Control for Use with Vaginal Swab Specimens
Authors: Cosentino Lisa A. , Landers Daniel V. , Hillier Sharon L. 
Published: August 2003

ABSTRACT

Vaginal swab specimens may be preferable to cervical swab or urine specimens for the detection of
Chlamydia trachomatis
and
Neisseria gonorrhoeae
because of the ease of specimen collection and transport. The purpose of this study was to evaluate whether vaginal swab specimens are equivalent to cervical swab specimens for the detection of
N. gonorrhoeae
and
C. trachomatis
by the Becton Dickinson strand displacement amplification assay (SDA) with the BDProbeTec ET instrument and then to evaluate the use of the amplification control in a clinical research setting. In the first phase, vaginal and cervical swab specimens were obtained from 455 symptomatic women aged 18 to 40 attending primary health care and sexually transmitted disease clinics. Thirty-nine specimens (8.6%) had true-positive results for
N. gonorrhoeae
and 37 specimens (8.1%) had true-positive results for
C. trachomatis
. The sensitivity of SDA was superior to that of culture for the detection of
N. gonorrhoeae
with vaginal swab specimens and equivalent to that of the Roche PCR for the detection of
C. trachomatis
with cervical swab specimens. In the second phase of the study, 1,411 consecutively collected vaginal swab specimens were evaluated, with 357 (25.3%) specimens giving indeterminate readings on the basis of the result for the amplification control. The prevalences of sexually transmitted pathogens in vaginal swab specimens with and without use of the amplification control were 6.0 and 5.8%, respectively, for
C. trachomatis
and 3.1 and 3.0%, respectively, for
N. gonorrhoeae.
Although, vaginal swab specimens were equivalent to cervical swab specimens for the detection of
N. gonorrhoeae
and
C. trachomatis
by SDA with respect to sensitivity, one in four vaginal swab specimens yielded an indeterminate result when the amplification control was used. The amplification control has limited value for use with vaginal swab specimens.
Activities of Caspofungin, Itraconazole, Posaconazole, Ravuconazole, Voriconazole, and Amphotericin B against 448 Recent Clinical Isolates of Filamentous Fungi
Authors: Diekema D. J. , Messer S. A. , Hollis R. J. , Jones R. N. , Pfaller M. A. 
Published: August 2003

ABSTRACT

We examined the in vitro activity of caspofungin, posaconazole, voriconazole, ravuconazole, itraconazole, and amphotericin B against 448 recent clinical mold isolates. The endpoint for reading caspofungin was the minimum effective concentration (MEC). Among the triazoles, posaconazole was most active, inhibiting 95% of isolates at ≤1 μg/ml, followed by ravuconazole (91%), voriconazole (90%), and itraconazole (79%). Caspofungin and amphotericin B inhibited 93% and 89% of isolates at ≤1 μg/ml, respectively, with caspofungin demonstrating an MEC 90 of 0.12 μg/ml. All three new triazoles and caspofungin inhibited >95% of
Aspergillus
spp. at ≤1 μg/ml compared to 83% for itraconazole and 91% for amphotericin B. Amphotericin B inhibited only 38% of
Aspergillus terreus
isolates at ≤1 μg/ml, whereas the three new triazoles and caspofungin inhibited all
A. terreus
at ≤0.5 μg/ml. The new triazoles and caspofungin have excellent in vitro activity against a very large collection of recent clinical isolates of
Aspergillus
spp., and some in vitro activity against selected other filamentous fungi.
Serodiagnosis of Syphilis: Antibodies to Recombinant Tp0453, Tp92, and Gpd Proteins Are Sensitive and Specific Indicators of Infection byTreponema pallidum
Authors: Van Voorhis Wesley C. , Barrett Lynn K. , Lukehart Sheila A. , Schmidt Bruno , Schriefer Martin , Cameron Caroline E. 
Published: August 2003

ABSTRACTSyphilis serodiagnosis relies on a combination of nonspecific screening tests (antilipoidal antibodies) andTreponema pallidum-specific tests (anti-T.pallidumantibodies). We studied a group of six recombinantT.pallidumantigens for their sensitivities and specificities with sera from individuals with syphilis (n= 43), relapsing fever (n= 8), Lyme disease (n= 8), and leptospirosis (n= 9) and from uninfected individuals (n= 15). Three recombinant proteins, Tp0155, Tp0483, and Tp0751, demonstrated sensitivity values that ranged from 28 to 42%. In contrast, three other recombinant proteins exhibited the following sensitivity and specificity values: Tp0453, 100% sensitivity and 100% specificity; Tp92 (Tp0326), 98% sensitivity and 97% specificity; and Gpd (Tp0257), 91% sensitivity and 93% specificity. Tp0453, Tp92, and Gpd also were recognized by sera from individuals with early primary syphilis that were nonreactive with the antilipoidal Venereal Disease Research Laboratory test. The reactivities of syphilis patient sera with Tp0453, Tp92, and Gpd were proportional to the titers of these sera with the treponemal test MHA-TP (microhemagglutination assay forT.pallidum). Thus, the recombinantT.pallidumantigens Tp0453, Tp92, and Gpd show promise as diagnostic antigens in the enzyme-linked immunosorbent assay-based assay.