bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic Variability in
Puccinia striiformis
f. sp.
tritici
Populations Sampled on a Local Scale during Natural Epidemics
Authors: Villaréal Lorys M. M. A. , Lannou Christian , de Vallavieille-Pope Claude , Neema Claire 
Published: November 2002

ABSTRACT

This study investigated genetic polymorphism on a local scale in
Puccinia striiformis
f. sp.
tritici
populations during natural epidemics, in four fields located in northern France and sampled in 1998 or 1999. Two hundred and forty-seven isolates were analyzed for their amplified fragment length polymorphism (AFLP) pattern through four primer combinations, and 194 of them were also tested for their virulence factors. Only one or two pathotypes were found in each field, and all isolates had virulence v17, matching the recently introduced
Yr17
resistance gene. Polymorphism on a field scale was low. Although 67 loci were polymorphic, 77% of the isolates had the same AFLP pattern, all other patterns being rare or unique. Analyses of the genetic distance between AFLP patterns based on the Jaccard index allowed us to define 12 groups, but a bootstrap analysis showed that all isolates could be assigned to a single clonal lineage. This leads us to conclude that
P. striiformis
f. sp.
tritici
populations are clonal on a field scale in northern France.
Construction of DNA-Shuffled and Incrementally Truncated Libraries by a Mutagenic and Unidirectional Reassembly Method: Changing from a Substrate Specificity of Phospholipase to That of Lipase
Authors: Song Jae Kwang , Chung Bora , Oh Young Hak , Rhee Joon Shick 
Published: November 2002

ABSTRACT

A method of mutagenic and unidirectional reassembly (MURA) that can generate libraries of DNA-shuffled and randomly truncated proteins was developed. The method involved fragmenting the template gene(s) randomly by DNase I and reassembling the small fragments with a unidirectional primer by PCR. The MURA products were treated with T4 DNA polymerase and subsequently with a restriction enzyme whose site was located on the region of the MURA primer. The N-terminal-truncated and DNA-shuffled library of a
Serratia
sp. phospholipase A
1
prepared by this method had an essentially random variation of truncated size and also showed point mutations associated with DNA shuffling. After high-throughput screening on triglyceride-emulsified plates, several mutants exhibiting absolute lipase activity (NPL variants) were obtained. The sequence analysis and the lipase activity assay on the NPL variants revealed that N-terminal truncations at a region beginning with amino acids 61 to 71, together with amino acid substitutions, resulted in the change of substrate specificity from a phospholipase to a lipase. We therefore suggest that the MURA method, which combines incremental truncation with DNA shuffling, can contribute to expanding the searchable sequence space in directed evolution experiments.
Molecular Subtype Analyses of
Campylobacter
spp. from Arkansas and California Poultry Operations
Authors: Hiett K. L , Stern N. J. , Fedorka-Cray P. , Cox N. A. , Musgrove M. T. , Ladely S. 
Published: November 2002

ABSTRACT

Campylobacter
isolates from diverse samples within broiler production and processing environments were typed by using
flaA
short variable region DNA sequence analysis. Sixteen flocks from four different farms representing two broiler producers in Arkansas and California were analyzed. Fourteen of the flocks (87.5%) were
Campylobacter
-positive; two remained negative throughout the 6-week rearing period. In general, multiple clones were present within a flock. Additionally, clones found within a flock were also present on the final product, although the diversity of
Campylobacter
spp. on the final product appeared to be reduced relative to that observed within the flock. Comparison of clones between flocks on the same farm revealed that some clones of
Campylobacter
persisted in multiple flocks. Furthermore, some clones were identified across the two farms that were under the same management. In two sampling periods, environmental isolates were positive for
Campylobacter
prior to flock shedding. Environmental samples associated with five additional flocks were positive for
Campylobacter
concomitantly with recovery of
Campylobacter
from the birds. Analysis of the environmental isolates that were positive prior to flock shedding demonstrated that in some instances the environmental isolates possessed genotypes identical to those of isolates originating from the flock, while in other cases the environmental isolates possessed genotypes that were distantly related to isolates obtained from the flock. Analyses of environmental isolates that tested positive concurrently with the positive isolates from the flocks demonstrated varied results; in some instances the environmental isolates possessed genotypes identical to those of isolates originating from the flock, while in other cases the environmental isolates possessed genotypes that were distantly related to isolates obtained from the flock. These data suggest that the external environment may contribute to
Campylobacter
contamination during poultry production and processing. However, environmental contamination with
Campylobacter
does not appear to be the sole contributing factor.
Direct Identification in Food Samples of
Listeria
spp. and
Listeria monocytogenes
by Molecular Methods
Authors: Cocolin Luca , Rantsiou Kalliopi , Iacumin Lucilla , Cantoni Carlo , Comi Giuseppe 
Published: November 2002

ABSTRACT

A new molecular approach for the detection and identification of
Listeria
spp. and
Listeria monocytogenes
in food is presented here. The method is based on the PCR amplification of a fragment of the
iap
gene from the five species belonging to the genus and on the analysis of the PCR products obtained by denaturing gradient gel electrophoresis (DGGE). The protocol was first optimized by using strains from international collections. Based on the differences present in the sequences amplified, it was possible to obtain species-specific DGGE migration that allowed fast and easy identification of
L. monocytogenes
,
L. innocua
,
L. welshimeri
,
L. seeligeri
, and
L. ivanovii
. Moreover, for
L. monocytogenes
serotypes, partial differentiation was possible. The optimized protocol was used for identification of
Listeria
strains traditionally isolated from food and for direct detection and identification of
Listeria
members in food after an overnight enrichment. Identification of 48 food isolates and direct detection of
Listeria
spp. in 73 food samples show the potential of the method that can be used as a fast screening test to investigate the presence of
Listeria
spp. and
L. monocytogenes
in food.
Detection of Dengue Virus Replication in Peripheral Blood Mononuclear Cells from Dengue Virus Type 2-Infected Patients by a Reverse Transcription-Real-Time PCR Assay
Authors: Wang Wei-Kung , Sung Tzu-Ling , Tsai Yu-Chen , Kao Chuan-Liang , Chang Shu-Mei , King Chwan-Chuen 
Published: November 2002

ABSTRACT
While dengue virus is thought to replicate in mononuclear phagocytic cells in vivo, attempts to detect it in peripheral blood mononuclear cells (PBMC) by virus isolation or antigen detection have had variable and generally low rates. In this study, we developed a reverse transcription (RT)-real-time PCR assay to quantify positive- and negative-sense RNA of dengue virus type 2 within the cells. The assay includes an RT step using either sense or antisense primer followed by a real-time PCR step using the designed primers and probe, which target a capsid region highly conserved in dengue virus type 2 strains. It can be used to monitor the dynamic change of intracellular dengue virus RNA species during the course of infection. When this assay is employed in quantification of dengue virus RNA species in PBMC from 10 patients infected with dengue virus type 2, both positive- and negative-sense dengue RNA can be detected, indicating that dengue virus is actively replicating in PBMC in vivo. Moreover, the amounts of negative-sense dengue virus RNA in PBMC correlate very well with the viral load of dengue virus in plasma, suggesting that quantification of negative-sense dengue virus RNA in PBMC may provide another indicator of dengue virus replication in vivo. Use of this convenient, sensitive, and accurate method of quantification in clinical samples from patients with different disease severity would further our understanding of the pathogenesis of dengue.
Antigenically Diverse Reference Strains and Autologous Strains ofActinobacillus actinomycetemcomitansAre Equally Efficient Antigens in Enzyme-Linked Immunosorbent Assay Analysis
Authors: Vilkuna-Rautiainen Tiina , Pussinen Pirkko J. , Mattila Kimmo , Vesanen Marja , Åhman Heidi , Doğan Başak , Asikainen Sirkka 
Published: November 2002

ABSTRACTActinobacillus actinomycetemcomitansis a major pathogen in periodontitis. Data on the clinical relevance of serum immunoglobulin G (IgG) antibody levels against this species are controversial. The aim of the present study was to elucidate how different strains used as antigens in enzyme-linked immunosorbent assay (ELISA) influence the detection of individuals with elevated serum IgG levels againstA. actinomycetemcomitans. We hypothesized that the highest antibody levels are targeted to the autologous strains. A total of 19 strains—six antigenically diverse reference strains (serotypes a through e and a nonserotypeable strain) and 13 serotyped autologous strains—were used as whole-cell antigens in ELISA. Serum samples were from 26 untreated adult patients with periodontitis, whose subgingival bacterial samples were either culture positive (n= 13) or culture negative (n= 13) forA. actinomycetemcomitans, and from 10 culture-negative nonperiodontitis subjects. The highest individual (P< 0.05) IgG levels against the reference strains were most commonly against serotypes a and b in patients and against serotype c in nonperiodontitis subjects. The culture-positive patients had the highest (P< 0.05) IgG antibody levels against their autologous strains and against the reference strains of the same serotype. On the contrary, for these patients the levels of antibody against the reference strains of other serotypes were comparable to those of the nonperiodontitis subjects. The results indicated that the serum IgG antibody levels againstA. actinomycetemcomitansstrongly depend on the strains used as antigens in the ELISA. Elevated serum IgG levels againstA. actinomycetemcomitanscan be detected equally well using either the autologous strains or a variety of antigenically diverse reference strains as antigens.
Colony Multiplex PCR Assay for Identification and Differentiation of
Campylobacter jejuni
,
C. coli
,
C. lari
,
C. upsaliensis
, and
C. fetus
subsp
. fetus
Authors: Wang Gehua , Clark Clifford G. , Taylor Tracy M. , Pucknell Chad , Barton Connie , Price Lawrence , Woodward David L. , Rodgers Frank G. 
Published: November 2002

ABSTRACT

A multiplex PCR assay was used to simultaneously detect genes from the five major clinically relevant
Campylobacter
spp. Those genes selected were
hipO
and 23S rRNA from
Campylobacter jejuni
;
glyA
from each of
C. coli
,
C. lari
, and
C. upsaliensis
; and
sapB2
from
C. fetus
subsp.
fetus
. The assay was evaluated with 137 clinical and environmental isolates and was found to be rapid and easy to perform and had a high sensitivity and specificity for characterizing isolates, even in mixed cultures.
Effects of phthalic anhydride modification on horseradish peroxidase stability and activity
Authors: O'Brien Anne Marie , Smith Andrew T. , Ó'Fágáin Ciarán 
Published: November 2002

AbstractPhthalic anhydride (PA) modification stabilizes horseradish peroxidase (HRP) by reversal of the positive charge on two of HRP's six lysine residues. Native and PA‐HRP had half‐inactivation temperatures of 51 and 65°C and half‐lives at 65°C of 4 and 17 min, respectively. PA‐HRP was more resistant to dimethylformamide at room temperature and tetrahydrofuran at 60°C and to unfolding by heat, guanidine chloride, EDTA, and the reducing agent tris(2‐carboxyethyl)phosphine hydrochloride. Binding of the hydrophobic probe Nile Red to the native enzyme and to PA‐HRP was similar. The kinetics of both HRPs with the substrates ABTS, ferrocyanide, ferulic acid, and indole‐3‐propionic acid were measured, as was binding of the inhibitor benzhydroxamic acid. Small improvements in the catalytic properties were detected. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 233–240, 2003.
Effect of shear stress on expression of a recombinant protein by Chinese hamster ovary cells
Authors: Keane Julian T. , Ryan David , Gray Peter P. 
Published: November 2002

AbstractA flow chamber was used to impart a steady laminar shear stress on a recombinant Chinese hamster ovary (CHO) cell line expressing human growth hormone (hGH). The cells were subjected to shear stress ranging from 0.005 to 0.80 N m−2. The effect of shear stress on the cell specific glucose uptake, cell specific hGH, and lactate productivity rates were calculated. No morphological changes to the cells were observed over the range of shear stresses examined. When the cells were subjected to 0.10 N m−2 shear in protein‐free media without Pluronic F‐68, recombinant protein production ceased with no change in cell morphology, whereas control cultures were expressing hGH at 0.35 μg/106 cells/h. Upon addition of the shear protectants, Pluronic F‐68 (0.2% [w/v]) or fetal bovine serum (1.0% [v/v] FBS), the productivity of the cells was restored. The effect of increasing shear stress on the cells in protein‐free medium containing Pluronic F‐68 was also investigated. Cell specific metabolic rates were calculated for cells under shear stress and for no‐shear control cultures performed in parallel, with shear stress rates expressed as a percentage of those obtained for control cultures. Upon increasing shear from 0.005 to 0.80 N m−2, the cell specific hGH productivity decreased from 100% at 0.005 N m−2 to 49% at 0.80 N m−2 relative to the no‐shear control. A concurrent increase in the glucose uptake rate from 115% at 0.01 N m−2 to 142% at 0.80 N m−2, and decreased lactate productivity from 92% to 50%, revealed a change in the yield of products from glucose compared with the static control. It was shown that shear stress, at sublytic levels in medium containing Pluronic F‐68, could decrease hGH specific productivity. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 211–220, 2003.
Height extrapolation of fire resistant non‐loadbearing steel framed walls
Authors: Collier P.C.R. 
Published: November 2002

AbstractA review of height extrapolation methods used in the past, by BRANZ, has shown that complex techniques based on temperature rises inducing deflections, curvature and detachment of studs from channels can be reduced to a simple empirical formula. Given that a wall system comprising a certain stud and lining configuration has to be proven by a fire resistance test, a premise that the same or closely similar thermal and structural conditions will be reproduced within the wall is the basis of the proposed method. Four key features (of height, stud depth, lining and temperature difference across the studs) affecting the general performance of a wall were examined to determine some key dependencies and isolate irrelevant parameters from further consideration. This approach was possible by taking a macroscopic view of a system as a whole, and by assuming for all height and stud depth combinations of a given system that the behaviour is similar and predictable to a high degree. Copyright © 2002 John Wiley & Sons, Ltd.
Biomedical implants and devices: Assessment of magnetic field interactions with a 3.0‐Tesla MR system
Authors: Shellock Frank G. 
Published: November 2002

AbstractPurposeTo evaluate magnetic field interactions for 109 different biomedical implants and devices in association with exposure to a 3.0‐Tesla magnetic resonance (MR) system.Materials and MethodsA total of 109 implants and devices (aneurysm clips, 32; clips, fasteners, and staples, 10; coils and stents, 10; heart valve prostheses and annuloplasty rings, 12; orthopedic implants, five; suture materials, 13; vascular access ports and accessories, 13; miscellaneous implants and devices, 14) were tested for magnetic field interactions at 3.0‐Tesla using previously‐described, standardized techniques to assess magnetic field translational attraction and torque.ResultsThe deflection angles and torque measurements ranged, respectively, from 0 to 16° and 0 to +2 for the aneurysm clips; 0 to 90° and 0 to +4 for the clips, fasteners, and staples; 0 to 47° and 0 to +4 for the coils and stents; 0 to 4° and 0 to +1 for the heart valve prostheses and annuloplasty rings; 0 to 12° and 0 to +2 for the orthopedic implants; 0 to 13° and 0 to +2 for the suture materials; 0 to 52° and 0 to +4 for the vascular access ports and accessories; and 0 to 28° and 0 to +3 for the miscellaneous implants and devices.ConclusionOf the 109 implants and devices assessed for magnetic field interactions at 3.0‐Tesla, four (4%) are potentially unsafe based on deflection angle criteria. The implications of these results for patients undergoing MR procedures at 3.0‐Tesla is discussed. Notably, these results are specific to the 3.0‐Tesla MR system used for this evaluation. J. Magn. Reson. Imaging 2002;16:721–732. © 2002 Wiley‐Liss, Inc.
Dynamic contrast‐enhanced myocardial perfusion imaging using saturation‐prepared TrueFISP
Authors: Schreiber Wolfgang Günther , Schmitt Melanie , Kalden Peter , Mohrs Oliver Klaus , Kreitner Karl‐Friedrich , Thelen Manfred 
Published: November 2002

AbstractPurposeTo develop and test a saturation‐recovery TrueFISP (SR‐TrueFISP) pulse sequence for first‐pass myocardial perfusion imaging.Materials and MethodsFirst‐pass magnetic resonance imaging (MRI) of Gd‐DTPA (2 mL) kinetics in the heart was performed using an SR‐TrueFISP pulse sequence (TR/TE/α = 2.6 msec/1.4 msec/55°) with saturation preparation TD = 30 msec before the TrueFISP readout. Measurements were also performed with a conventional saturation‐recovery TurboFLASH (SRTF) pulse sequence for comparison.ResultsSR‐TrueFISP images were of excellent quality and demonstrated contrast agent wash‐in more clearly than SRTF images. The signal increase in myocardium was higher in SR‐TrueFISP than in SRTF data. Precontrast SNR and peak CNR were not significantly different between both sequences despite 57% improved spatial resolution for SR‐TrueFISP.ConclusionSR‐TrueFISP first‐pass MRI of myocardial perfusion leads to a substantial improvement of image quality and spatial resolution. It is well suited for first‐pass myocardial perfusion studies at cardiovascular MR systems with improved gradient hardware. J. Magn. Reson. Imaging 2002;16:641–652. © 2002 Wiley‐Liss, Inc.
Preoperative evaluation of gallbladder carcinoma: Efficacy of combined use of MR imaging, MR cholangiography, and contrast‐enhanced dual‐phase three‐dimensional MR angiography
Authors: Kim Jung Hoon , Kim Tae Kyoung , Eun Hyo Won , Kim Bong Soo , Lee Moon‐Gyu , Kim Pyo Nyun , Ha Hyun Kwon 
Published: November 2002

AbstractPurposeTo determine the efficacy of the combined use of magnetic resonance (MR) imaging, MR cholangiography (MRC), and MR angiography (MRA) in the preoperative evaluation of gallbladder carcinoma.Materials and MethodsDuring a 20‐month period, 41 patients with proven gallbladder carcinomas were referred for MR examination, including MR imaging, MRC, and gadolinium‐enhanced dual‐phase MRA to determine the operability of their gallbladder carcinoma. Eighteen patients who underwent surgery within six days of the MR examination were included in this study. All MR images were analyzed in order to assess bile duct invasion, vascular invasion, hepatic invasion or metastasis, lymph node metastasis, and invasion into adjacent organs.ResultsSurgical and histopathologic findings revealed hepatic invasion in nine patients, bile duct invasion in nine, vascular invasion in three, and lymph node metastasis in 10. The sensitivity and specificity of MR examination were, respectively, 100% and 89% for bile duct invasion, 100% and 87% for vascular invasion, 67% and 89% for hepatic invasion, and 56% and 89% for lymph node metastasis.ConclusionThe “all‐in‐one” MR protocol, including MR imaging, MRC, and MRA, can be an effective diagnostic method in the preoperative work‐up for gallbladder carcinoma. J. Magn. Reson. Imaging 2002;16:676–684. © 2002 Wiley‐Liss, Inc.
Nitric oxide in patients with transitional bladder cancer
Authors: Eiján Ana María , Piccardo Inés , Riveros María Doris , Sandes Eduardo Omar , Porcella Hugo , Jasnis María Adela , Sacerdote De Lustig Eugenia , Malagrino Hector , Pasik Leonardo , Casabé Alberto Ricardo 
Published: November 2002

AbstractBackground and ObjectivesOne of the current challenges in clinical oncology is the identification of patients with superficial transitional bladder carcinoma (TBC) at high risk of recurrence or myoinvasive disease. Recently, inducible nitric oxide synthase (iNOS) expression was detected in urinary bladder cancers. Because iNOS produces a high concentration of nitric oxide (NO), we thought it possible that urine from TBC patients produces high levels of NO. The aim of this study was to determine urine NO levels in TBC compared with healthy controls and with patients bearing other nonrelated tumors, as well as to examine iNOS expression in bladder cancer tissue.MethodsThis study evaluated patients with TBC (n = 33), with gynecological tumors (GT) (n = 19), TBC patients with no evidence of tumor (no evidence of disease [NED]) (n = 19), and healthy subjects (n = 39). Urine NO levels were determined by Griess reagent, expressed as μM NO2−/100 mg creatinine.ResultsTBC patients produced significantly higher urine NO median values (4.2 μM; range, 2.1–91.6) than were produced by healthy individuals (2.1 μM; range, 0.4–4.9), by the NED group (1.7 μM; range 1.2–5.4), and by GT patients (2.0 μM; range, 0.8–58.1) (P = 0.000, Kruskal‐Wallis test). iNOS was detected by Western blot in 52% (13/25) of bladder tumors examined.ConclusionsAlthough a wider study is necessary, our results suggest that the enhanced NO levels could perhaps be considered as a putative marker in TBC patients. J. Surg. Oncol. 2002;81:203–208. © 2002 Wiley‐Liss, Inc.
Fisher syndrome or Bickerstaff brainstem encephalitis? Anti‐GQ1b IgG antibody syndrome involving both the peripheral and central nervous systems
Authors: Ogawara Kazue , Kuwabara Satoshi , Yuki Nobuhiro 
Published: November 2002

AbstractWe describe a 27‐year‐old woman who showed the clinical triad of Fisher syndrome (ophthalmoplegia, ataxia, and areflexia), a disturbance of consciousness, facial diplegia, and hemisensory loss. Her serum was positive for anti‐GQ1b immunoglobulin G (IgG) antibody. The electroencephalographic findings (diffuse slow activity), median somatosensory evoked potential (absent cortical N20 with normal cervical N13), and blink reflex studies (absent R2) suggested central dysfunction, whereas results of facial nerve conduction studies (low amplitudes of compound muscle action potentials), F‐wave and H‐reflex studies (absent F‐waves and soleus H‐reflexes), and brainstem auditory evoked potentials (prolongation of wave I latency) suggested peripheral abnormalities. This case supports the hypothesized continuity between Fisher syndrome and Bickerstaff brainstem encephalitis. These two conditions may represent a single autoimmune disease mediated by anti‐GQ1b antibody, usually involving the peripheral and occasionally the central nervous systems. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 000‐000, 2002