bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dispersal and recruitment dynamics in the fleshy‐fruited Persoonia lanceolata (Proteaceae)
Authors: Auld Tony D. , Denham Andrew J. , Turner Ken 
Published: February 2009

AbstractQuestion: What is the role of dispersal, persistent soil seed banks and seedling recruitment in population persistence of fleshy‐fruited obligate seeding plant species in fire‐prone habitats?Location: Southeastern Australia.Methods: We used a long‐term study of a shrubby, fleshy‐fruited Persoonia species (Proteaceae) to examine (1) seed removal from beneath the canopy of adult plants; (2) seedling recruitment after fire; (3) the magnitude and location of the residual soil seed bank; and (4) the implications for fire management of obligate seeding species. We used demographic sampling techniques combined with Generalised Linear Modelling and regression to quantify population changes over time.Results: Most of the mature fruits (90%) on the ground below the canopy of plants were removed by Wallabia bicolor (Swamp wallaby) with 88% of seeds extracted from W. bicolor scats viable and dormant. Wallabies play an important role in moving seeds away from parent plants. Their role in occasional long distance dispersal events remains unknown. We detected almost no seed predation in situ under canopies (< 1%). Seedling recruitment was cued to fire, with post‐fire seedling densities 6‐7 times pre‐fire adult densities. After fire, a residual soil seed bank was present, as many seeds (77‐100%) remained dormant and viable at a soil depth where successful future seedling emergence is possible (0‐5 cm). Seedling survival was high (> 80%) with most mortality within 2 years of emergence. Plant growth averaged 17 cm per year. The primary juvenile period of plants was 7–8 years, within the period of likely return fire intervals in the study area. We predicted that the study population increased some five‐fold after the wildfire at the site.Conclusions: Residual soil seed banks are important, especially in species with long primary juvenile periods, to buffer the populations against the impact of a second fire occurring before the seed bank is replenished.
Filtering processes in the assembly of plant communities: Are species presence and abundance driven by the same traits?
Authors: Cingolani Ana M. , Cabido Marcelo , Gurvich Diego E. , Renison Daniel , Díaz Sandra 
Published: February 2009

AbstractQuestion: Is the response of plant traits to environment at the community level similar when considering species abundance and when considering species presence only?Location: Mountain grasslands, central Argentina.Methods: We used data from 57 floristic samples, ordinated through DCCA along moisture and grazing gradients combined with trait values from 85 species (plant height, leaf area, leaf thickness leaf toughness and SLA). For each sample, we calculated the weighted average (considering species abundance) and the simple average (considering only species presence). Through multiple regressions we analysed how each average (dependent variable) responded to moisture and grazing (DCCA scores along Axes 1 and 2, respectively, as independent variables).Results: Weighted averages of all traits were significantly associated to both gradients, while simple averages did not always respond. In some cases the responses followed similar but weaker trends than the responses of weighted averages, but in other cases these responses were qualitatively different. Traits more associated with size (plant height, leaf area, leaf thickness) responded more consistently (similar trends for both averages) to grazing than to moisture, while traits more associated with plant resource acquisition (SLA, leaf toughness) responded more consistently to moisture than to grazing.Conclusion: The trait values and combinations which determine the probability of species presence are not necessary the same as those which determine their probability of becoming abundant. To understand community assembly rules, both species presence and species abundance should be taken into account as the result of different, although closely linked, filtering processes.
Evaluation of the platelet counting by Abbott CELL‐DYN® SAPPHIRE™ haematology analyser compared with flow cytometry
Authors: GRIMALDI E. , DEL VECCHIO L. , SCOPACASA F. , LO PARDO C. , CAPONE F. , PARIANTE S. , SCALIA G. , CATERINA M. DE 
Published: February 2009

SummaryThe Abbot Cell‐Dyn Sapphire is a new generation haematology analyser. The system uses optical/fluorescence flow cytometry in combination with electronic impedance to produce a full blood count. Optical and impedance are the default methods for platelet counting while automated CD61‐immunoplatelet analysis can be run as selectable test. The aim of this study was to determine the platelet count performance of the three counting methods available on the instrument and to compare the results with those provided by Becton Dickinson FACSCalibur flow cytometer used as reference method. A lipid interference experiment was also performed. Linearity, carryover and precision were good, and satisfactory agreement with reference method was found for the impedance, optical and CD61‐immunoplatelet analysis, although this latter provided the closest results in comparison with flow cytometry. In the lipid interference experiment, a moderate inaccuracy of optical and immunoplatelet counts was observed starting from a very high lipid value.
Evaluation of three automated chromogenic FVIII kits for the diagnosis of mild discrepant haemophilia A
Authors: RODGERS S. E. , DUNCAN E. M. , SOBIERAJ‐TEAGUE M. , LLOYD J. V. 
Published: February 2009

SummaryIn some mild haemophilia A patients (discrepant phenotype), coagulation FVIII levels by one‐stage assay (FVIII‐1st) are more than double those by classical two‐stage coagulation assay (FVIII‐2st), and may fall within the normal range. Our aim was to assess automated two‐stage chromogenic FVIII assays (FVIII‐chr) for diagnosis of mild discrepant haemophilia A. Three chromogenic FVIII kits (Biophen, Coamatic and Dade‐Behring) were evaluated, using recommended and extended incubation times. Samples were tested from patients with discrepant haemophilia (n = 7) and equivalent mild haemophilia (agreement between FVIII‐1st and FVIII‐2st, n = 4). For equivalent haemophilia, FVIII‐chr were consistent with FVIII‐1st and FVIII‐2st for all kits at all incubation times. For discrepant haemophilia, using recommended incubation times, mean FVIII‐chr using Biophen reagents was 22 IU/dl (range 13–31), with Coamatic 26 (17–34) and with Dade‐Behring 41 (33–47), compared with 36 (27–44) for FVIII‐1st and 8 (6–9) for FVIII‐2st. FVIII‐chr decreased as incubation time was increased with Biophen and Coamatic, but decreased less with Dade‐Behring. FVIII‐chr using the Dade‐Behring kit gave similar results to FVIII‐1st and is not suitable for diagnosis of mild discrepant haemophilia A. FVIII‐chr by Biophen and Coamatic kits is suitable for diagnosis of these patients, especially with an extended incubation time.
Auer rod‐like intracytoplasmic inclusions in multiple myeloma. A case report and review of the literature
Authors: HÜTTER G. , NOWAK D. , BLAU I. W. , THIEL E. 
Published: February 2009

SummarySeveral intracytoplasmic morphological changes in the plasma cells of multiple myeloma have been described previously. However, Auer rod‐like inclusions are rarely found in these types of cells. Here, we report a case of multiple myeloma with Auer rod‐like, needle‐shaped intracytoplasmic inclusions in plasma cells. A review of all published cases revealed that this phenomenon is exclusively found in myeloma with kappa‐type paraprotein. The nature of these intracellular inclusions and the relationship to prognostic implications and concomitant illnesses are discussed.
Relationships between platelet counts, platelet volumes and reticulated platelets in patients with ITP: evidence for significant platelet count inaccuracies with conventional instrument methods
Authors: DIQUATTRO M. , GAGLIANO F. , CALABRÒ G. M. , TOMMASI M. , SCOTT C. S. , MANCUSO G. , PALMA B. , MENOZZI I. 
Published: February 2009

SummaryThe platelet count has a primary role in the diagnosis and treatment of idiopathic thrombocytopenic purpura (ITP). This study analysed the accuracy of ITP patient platelet counts determined by Abbott CD‐Sapphire (impedance/optical) and Bayer Advia 120 (optical) analyses, compared with a reference immunoplatelet method. Instrument platelet estimates showed broad equivalence in the higher range of observed values, but significant discrepancies against the immunoplatelet count were seen when platelet counts were <10 × 109/l. CD‐Sapphire mean platelet volume (MPV) results revealed increased (>12 fl) platelet volumes in eight of eight ITP patients with counts of <20 × 109/l compared with 6/6 and 5/13 patients with platelet counts of 20–50 and >50 × 109/l. In contrast, Bayer Advia MPV values showed no relationship with the platelet count. Increased reticulated platelets were associated with an increasing CD‐Sapphire MPV (R2 = 0.61) and a decreasing platelet count. High (>40%) reticulated platelet values were seen in 9/9 patients with immunoplatelet counts of <20 × 109/l compared with 0/19 patients with platelet counts above 20 × 109/l. There may be a need for caution in the interpretation of platelet counts in ITP patients obtained with conventional instrument methods, and therapeutic decisions should ideally be validated by reference immunoplatelet procedures.
Molecular Genetics of
para
-Aminosalicylic Acid Resistance in Clinical Isolates and Spontaneous Mutants of
Mycobacterium tuberculosis
Authors: Mathys Vanessa , Wintjens René , Lefevre Philippe , Bertout Julie , Singhal Amit , Kiass Mehdi , Kurepina Natalia , Wang Xiao-Ming , Mathema Barun , Baulard Alain , Kreiswirth Barry N. , Bifani Pablo 
Published: February 2009

ABSTRACT

The emergence of
Mycobacterium tuberculosis
resistant to first-line antibiotics has renewed interest in second-line antitubercular agents. Here, we aimed to extend our understanding of the mechanisms underlying para-aminosalicylic acid (PAS) resistance by analysis of six genes of the folate metabolic pathway and biosynthesis of thymine nucleotides (
thyA, dfrA, folC, folP1, folP2
, and
thyX
) and three
N
-acetyltransferase genes [
nhoA, aac(1)
, and
aac(2)
] among PAS-resistant clinical isolates and spontaneous mutants. Mutations in
thyA
were identified in only 37% of the clinical isolates and spontaneous mutants. Overall, 24 distinct mutations were identified in the
thyA
gene and 3 in the
dfrA
coding region. Based on structural bioinformatics techniques, the altered ThyA proteins were predicted to generate an unfolded or dysfunctional polypeptide. The MIC was determined by Bactec/Alert and dilution assay. Sixty-three percent of the PAS-resistant isolates had no mutations in the nine genes considered in this study, revealing that PAS resistance in
M. tuberculosis
involves mechanisms or targets other than those pertaining to the biosynthesis of thymine nucleotides. The alternative mechanism(s) or pathway(s) associated with PAS resistance appears to be PAS concentration dependent, in marked contrast to
thyA
-mutated PAS-resistant isolates.
Substrate-Induced Inactivation of the
Escherichia coli
AmiD
N
-Acetylmuramoyl-
l
-Alanine Amidase Highlights a New Strategy To Inhibit This Class of Enzyme
Authors: Pennartz Anne , Généreux Catherine , Parquet Claudine , Mengin-Lecreulx Dominique , Joris Bernard 
Published: February 2009

ABSTRACT

In the eubacterial cell, the peptidoglycan is perpetually hydrolyzed throughout the cell cycle by different enzymes such as lytic transglycosylases, endopeptidases, and amidases. In
Escherichia coli
, four
N
-acetylmuramoyl-
l
-alanine amidases, AmiA, -B, -C, and -D, are present in the periplasm. AmiA, -B, and -C are soluble enzymes, whereas AmiD is a lipoprotein anchored in the outer membrane. To determine more precisely the specificity and the kinetic parameters of AmiD, we overproduced and purified the native His-tagged AmiD in the presence of detergent and a soluble truncated form of this enzyme by removing its signal peptide and the cysteine residue responsible for its lipidic anchorage. AmiD is a zinc metalloenzyme and is inactivated by a metal chelator such as EDTA. Native His-tagged and truncated AmiD hydrolyzes peptidoglycan fragments that have at least three amino acids in their peptide chains, and the presence of an anhydro function on the
N
-acetylmuramic acid is not essential for its activity. The soluble truncated AmiD exhibits a biphasic kinetic time course that can be explained by the inactivation of the enzyme by the substrate. This behavior highlights a new strategy to inhibit this class of enzymes.
Binding of Faropenem and Other β-Lactam Agents to Penicillin-Binding Proteins of Pneumococci with Various β-Lactam Susceptibilities
Authors: Kosowska-Shick Klaudia , McGhee Pamela , Appelbaum Peter C. 
Published: February 2009

ABSTRACT

Faropenem demonstrated low MICs (≤1 μg/ml) for all penicillin-susceptible and nonsusceptible pneumococci and exhibited very strong abilities to bind to
Streptococcus pneumoniae
penicillin-binding proteins (PBPs), except for PBP2X. The lower faropenem affinity for PBP2X did not affect MICs for any strains tested, and only imipenem had lower MICs, with much lower binding affinities for all PBPs tested, than faropenem.
Transcription of Inflammatory Genes in the Lung after Infection with Community-Associated Methicillin-Resistant
Staphylococcus aureus
: a Role for Panton-Valentine Leukocidin?
Authors: Montgomery Christopher P. , Daum Robert S. 
Published: February 2009

ABSTRACT

Necrotizing pneumonia caused by community-associated methicillin-resistant
Staphylococcus aureus
(CA-MRSA) isolates is increasingly common and frequently severe. The early inflammatory response in the lung after CA-MRSA infection remains largely undefined. Additionally, many workers have hypothesized that the Panton-Valentine leukocidin (PVL) is a key virulence determinant in CA-MRSA necrotizing pneumonia. We hypothesized that intratracheal inoculation of rats with a USA300 CA-MRSA isolate would result in early expression of genes involved in the immune response and that this would correlate with inflammation and tissue destruction characteristic of necrotizing pneumonia. In addition, we hypothesized that infection with a PVL deletion mutant would result in an attenuated early host response. Infection of rats with a sublethal inoculum of USA300 (strain LAC) resulted in rapid increased expression of most cytokine, chemokine, and inflammatory receptor gene transcripts studied, as assessed by quantitative real-time reverse transcriptase PCR (qRT-PCR). The increased gene transcription was followed by inflammation, increased bacterial survival in the lungs, and necrotizing pneumonia. Infection with strain LAC and infection with strain LAC Δ
pvl
(
lukSF-PV
deletion mutant) resulted in indistinguishable diseases, as assessed by mortality, in vivo bacterial recovery, and pulmonary pathology. Assessment of the transcription of inflammatory genes by qRT-PCR also revealed little difference after infection with LAC and after infection with LAC Δ
pvl
, either in animals that died or in animals that survived to 24 h after inoculation. We conclude that in a rat model of necrotizing pneumonia, there was an early, brisk inflammatory transcriptional response associated with neutrophil recruitment and tissue destruction. Deletion of
lukSF-PV
did not alter the early immune response to CA-MRSA in the lung.
Cholera Caused by
Vibrio cholerae
O1 Induces T-Cell Responses in the Circulation
Authors: Bhuiyan Taufiqur Rahman , Lundin Samuel B. , Khan Ashraful Islam , Lundgren Anna , Harris Jason B. , Calderwood Stephen B. , Qadri Firdausi 
Published: February 2009

ABSTRACT

Considerable effort is being made to understand the acute and memory antibody responses in natural cholera infection, while rather less is known about the roles of cellular immune responses involving T and B lymphocytes. We studied responses in adult patients hospitalized with cholera caused by
Vibrio cholerae
O1. Peripheral blood mononuclear cells from patients (
n
= 15) were analyzed by flow cytometry after stimulation with
V. cholerae
O1 membrane protein (MP) or toxin-coregulated pilus antigen (TcpA). The gamma interferon (IFN-γ) and interleukin-13 (IL-13) responses in stimulated-lymphocyte supernatants were studied. The responses were compared with those of healthy controls (
n
= 10). Patients responded with increased frequencies of gut-homing CD4
+
T cells (CD4
+
β7
+
), gut-homing CD8
+
T cells (CD8
+
β7
+
), and gut-homing B cells (CD19
+
β7
+
) at the early and/or late convalescent stages compared to the acute stage. After stimulation with MP or TcpA, proliferation of CD4
+
and CD8
+
T cells was increased at the acute stage and/or early convalescent stage compared to healthy controls. Increased IL-13 and IFN-γ responses were observed after antigenic stimulation at the acute and convalescent stages compared to healthy controls. Thus, increases in the levels of gut-homing T and B cells, as well as involvement of CD8 and CD4 Th1-mediated (IFN-γ) and CD4 Th2-mediated (IL-13) cytokine responses, take place in acute dehydrating disease caused by
V. cholerae
O1. Further studies are needed to determine if such responses are also stimulated after immunization with oral cholera vaccines and if these responses play a role in protection following exposure to cholera.
Yersinia pestisIS1541Transposition Provides for Escape from Plague Immunity
Authors: Cornelius Claire A. , Quenee Lauriane E. , Elli Derek , Ciletti Nancy A. , Schneewind Olaf 
Published: February 2009

ABSTRACTYersinia pestisis perhaps the most feared infectious agent due to its ability to cause epidemic outbreaks of plague disease in animals and humans with high mortality. Plague infections elicit strong humoral immune responses against the capsular antigen (fraction 1 [F1]) ofY. pestis, and F1-specific antibodies provide protective immunity. Here we asked whetherY. pestisgenerates mutations that enable bacterial escape from protective immunity and isolated a variant with an IS1541insertion incaf1Aencoding the F1 outer membrane usher. Thecaf1A::IS1541insertion prevented assembly of F1 pili and provided escape from plague immunity via F1-specific antibodies without a reduction in virulence in mouse models of bubonic or pneumonic plague. F1-specific antibodies interfere withY. pestistype III transport of effector proteins into host cells, an inhibitory effect that was overcome by thecaf1A::IS1541insertion. These findings suggest a model in which IS1541insertion intocaf1Aprovides for reversible changes in envelope structure, enablingY. pestisto escape from adaptive immune responses and plague immunity.
Characterization and Studies of the Cellular Interaction of Native Colonization Factor CS6 Purified from a Clinical Isolate of Enterotoxigenic
Escherichia coli
Authors: Ghosal Abhisek , Bhowmick Rudra , Banerjee Rajat , Ganguly Sandipan , Yamasaki S. , Ramamurthy T. , Hamabata T. , Chatterjee Nabendu Sekhar 
Published: February 2009

ABSTRACT

CS6 is a widely expressed colonization factor of enterotoxigenic
Escherichia coli
(ETEC). To date, CS6 has not been well characterized in its native state. Here, we purified CS6 for the first time from an ETEC clinical isolate. Purified CS6 was composed of two structural subunits, CssA and CssB, which were present in equal amounts and tightly linked through noncovalent, detergent-stable association. The CssA subunit was poorly immunogenic, whereas CssB was highly immunogenic. Although the predicted molecular mass of CssA is 15 kDa, the purified CssA has an effective molecular mass of 18.5 kDa due to fatty acid modification. When purified CS6 was screened for its ability to bind with different extracellular matrix proteins, fibronectin (Fn) was found to interact with CS6 as well as CssA in a dose-dependent and saturable manner. This interaction was inhibited both by a synthetic peptide corresponding to the C-terminal hydrophilic, surface-exposed region of CssA (positions 112 to 126) and by the antibody derived against this region. Enzyme-linked immunosorbent assay results showed that CssA interacted with the 70-kDa N-terminal domain of Fn. The modifications on CssA probably do not play a role in Fn binding. Preincubation of INT 407 cells with CssA, but not CssB, inhibited ETEC binding to these cells. The results suggested that CS6-expressing ETEC binds to Fn of INT 407 cells through the C-terminal region of CssA. Purified CS6 was found to colocalize with Fn along the junctions of INT 407 cells. Based on the results obtained, we propose that CS6-expressing ETEC binds to the intestinal cells through Fn for colonization.
Francisella tularensisPhagosomal Escape Does Not Require Acidification of the Phagosome
Authors: Clemens Daniel L. , Lee Bai-Yu , Horwitz Marcus A. 
Published: February 2009

ABSTRACTFollowing uptake,Francisella tularensisenters a phagosome that acquires limited amounts of lysosome-associated membrane glycoproteins and does not acquire cathepsin D or markers of secondary lysosomes. With additional time after uptake,F. tularensisdisrupts its phagosomal membrane and escapes into the cytoplasm. To assess the role of phagosome acidification in phagosome escape, we followed acidification using the vital stain LysoTracker red and acquisition of the proton vacuolar ATPase (vATPase) using immunofluorescence within the first 3 h after uptake of live or killedF. tularensissubsp.holarcticalive vaccine strain (LVS) by human macrophages. Whereas 90% of the phagosomes containing killed LVS stained intensely for the vATPase and were acidified, only 20 to 30% of phagosomes containing live LVS stained intensely for the vATPase and were acidified. To determine whether transient acidification might be required for phagosome escape, we assessed the impact on phagosome permeabilization of the proton pump inhibitor bafilomycin A. Using electron microscopy and an adenylate cyclase reporter system, we found that bafilomycin A did not prevent phagosomal permeabilization byF. tularensisLVS or virulent type A strains (F. tularensissubsp.tularensisstrain Schu S4 and a recent clinical isolate) or by “F. tularensissubsp.novicida,” indicating thatF. tularensisdisrupts its phagosomal membrane by a mechanism that does not require acidification.
Development of Multiplex PCR Assays for Detection of Enterotoxigenic
Escherichia coli
Colonization Factors and Toxins
Authors: Rodas Claudia , Iniguez Volga , Qadri Firdausi , Wiklund Gudrun , Svennerholm Ann-Mari , Sjöling Åsa 
Published: February 2009

ABSTRACT

Four multiplex PCR assays for detection of 19 enterotoxigenic
Escherichia coli
(ETEC) colonization factors and an improved ETEC toxin multiplex PCR were developed and tested on Bangladeshi and Bolivian ETEC strain collections. The assays will be useful for surveillance of ETEC infections in diagnostic laboratories that have access to PCR.
Predicting Clearance of Colonization with Vancomycin-Resistant Enterococci and Methicillin-Resistant
Staphylococcus aureus
by Use of Weekly Surveillance Cultures
Authors: Huckabee Charmaine M. , Huskins W. Charles , Murray Patrick R. 
Published: February 2009

ABSTRACT

We analyzed surveillance cultures for vancomycin-resistant enterococci (VRE) and methicillin-resistant
Staphylococcus aureus
(MRSA) collected during a multicenter trial to determine if three negative cultures collected at weekly intervals would predict clearance of VRE or MRSA from colonized patients. Seventy-two percent of VRE-colonized patients and 94% of MRSA-colonized patients were culture negative after three consecutive negative cultures.