bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Sand and Sawdust Bedding Materials on the Fecal Prevalence of
Escherichia coli
O157:H7 in Dairy Cows
Authors: LeJeune Jeffrey T. , Kauffman Michael D.
Published: January 2005

Farm management practices that reduce the prevalence of food-borne pathogens in live animals are predicted to enhance food safety. To ascertain the potential role of livestock bedding in the ecology and epidemiology of
Escherichia coli
O157:H7 on farms, the survival of this pathogen in used-sand and used-sawdust dairy cow bedding was determined. Additionally, a longitudinal study of mature dairy cattle housed on 20 commercial dairy farms was conducted to compare the prevalence of
E. coli
O157:H7 in cattle bedded on sand to that in cattle bedded on sawdust.
E. coli
O157:H7 persisted at higher concentrations in used-sawdust bedding than in used-sand bedding. The overall average herd level prevalence (3.1 versus 1.4%) and the number of sample days yielding any tests of feces positive for
E. coli
O157:H7 (22 of 60 days versus 13 of 60 days) were higher in sawdust-bedded herds. The choice of bedding material used to house mature dairy cows may impact the prevalence of
E. coli
O157:H7 on dairy farms.
Roseobacter
-Like Bacteria in Red and Mediterranean Sea Aerobic Anoxygenic Photosynthetic Populations
Authors: Oz Aia , Sabehi Gazalah , Koblízek Michal , Massana Ramon , Béjà Oded
Published: January 2005

Bacteriochlorophyll
a
-containing aerobic anoxygenic phototrophs (AAnP) have been proposed to account for up to 11% of the total surface water microbial community and to potentially have great ecological importance in the world's oceans. Recently, environmental and genomic data based on analysis of the
pufM
gene identified the existence of α-proteobacteria as well as possible γ-like proteobacteria among AAnP in the Pacific Ocean. Here we report on analyses of environmental samples from the Red and Mediterranean Seas by using
pufM
as well as the
bchX
and
bchL
genes as molecular markers. The majority of photosynthesis genes retrieved from these seas were related to
Roseobacter
-like AAnP sequences. Furthermore, the sequence of a novel photosynthetic operon organization from an uncultured
Roseobacter
-like bacterial artificial chromosome retrieved from the Red Sea is described. The data show the presence of
Roseobacter
-like bacteria in Red and Mediterranean Sea AAnP populations in the seasons analyzed.
Cloning of
Beauveria bassiana
Chitinase Gene
Bbchit1
and Its Application To Improve Fungal Strain Virulence
Authors: Fang Weiguo , Leng Bo , Xiao Yuehua , Jin Kai , Ma Jincheng , Fan Yanhua , Feng Jing , Yang Xingyong , Zhang Yongjun , Pei Yan
Published: January 2005

Entomopathogenic fungi can produce a series of chitinases, some of which act synergistically with proteases to degrade insect cuticle. However, chitinase involvement in insect fungus pathogenesis has not been fully characterized. In this paper, an endochitinase, Bbchit1, was purified to homogeneity from liquid cultures of
Beauveria bassiana
grown in a medium containing colloidal chitin. Bbchit1 had a molecular mass of about 33 kDa and pI of 5.4. Based on the N-terminal amino acid sequence, the chitinase gene,
Bbchit1
, and its upstream regulatory sequence were cloned.
Bbchit1
was intronless, and there was a single copy in
B. bassiana
. Its regulatory sequence contained putative CreA/Crel carbon catabolic repressor binding domains, which was consistent with glucose suppression of
Bbchit1
. At the amino acid level, Bbchit1 showed significant similarity to a
Streptomyces avermitilis
putative endochitinase, a
Streptomyces coelicolor
putative chitinase, and
Trichoderma harzianum
endochitinase Chit36Y. However,
Bbchit1
had very low levels of identity to other chitinase genes previously isolated from entomopathogenic fungi, indicating that
Bbchit1
was a novel chitinase gene from an insect-pathogenic fungus. A
gpd-Bbchit1
construct, in which
Bbchit1
was driven by the
Aspergiullus nidulans
constitutive promoter, was transformed into the genome of
B. bassiana
, and three transformants that overproduced Bbchit1 were obtained. Insect bioassays revealed that overproduction of Bbchit1 enhanced the virulence of
B. bassiana
for aphids, as indicated by significantly lower 50% lethal concentrations and 50% lethal times of the transformants compared to the values for the wild-type strain.
Role of Oxalic Acid Overexcretion in Transformations of Toxic Metal Minerals by
Beauveria caledonica
Authors: Fomina M. , Hillier S. , Charnock J. M. , Melville K. , Alexander I. J. , Gadd G. M.
Published: January 2005

The fungus
Beauveria caledonica
was highly tolerant to toxic metals and solubilized cadmium, copper, lead, and zinc minerals, converting them into oxalates. This fungus was found to overexcrete organic acids with strong metal-chelating properties (oxalic and citric acids), suggesting that a ligand-promoted mechanism was the main mechanism of mineral dissolution. Our data also suggested that oxalic acid was the main mineral-transforming agent. Cadmium, copper, and zinc oxalates were precipitated by the fungus in the local environment and also in association with the mycelium. The presence of toxic metal minerals often led to the formation of mycelial cords, and in the presence of copper-containing minerals, these cords exhibited enhanced excretion of oxalic acid, which resulted in considerable encrustation of the cords by copper oxalate hydrate (moolooite). It was found that
B. caledonica
hyphae and cords were covered by a thick hydrated mucilaginous sheath which provided a microenvironment for chemical reactions, crystal deposition, and growth. Cryo-scanning electron microscopy revealed that mycogenic metal oxalates overgrew parental fungal hyphae, leaving a labyrinth of fungal tunnels within the newly formed mineral matter. X-ray absorption spectroscopy revealed that oxygen ligands played a major role in metal coordination within the fungal biomass during the accumulation of mobilized toxic metals by
B. caledonica
mycelium; these ligands were carboxylic groups in copper phosphate-containing medium and phosphate groups in pyromorphite-containing medium.
Non-
Frankia
Actinomycetes Isolated from Surface-Sterilized Roots of
Casuarina equisetifolia
Fix Nitrogen
Authors: Valdés María , Pérez Néstor-Octavio , Estrada-de los Santos Paulina , Caballero-Mellado Jesús , Peña-Cabriales Juan José , Normand Philippe , Hirsch Ann M.
Published: January 2005

Based on partial 16S sequences, we previously described a novel group of nonsymbiotic, acetylene reduction activity-positive actinomycetes which were isolated from surface-sterilized roots of
Casuarina equisetifolia
growing in Mexico. An amplified rRNA restriction analysis confirmed that these actinomycetes are distinct from
Frankia
, a finding substantiated by a 16S rRNA gene phylogenetic analysis of two of the Mexican isolates. Further support for these actinomycetes being separate from
Frankia
comes from the very low DNA-DNA homology that was found. Nevertheless, the Mexican isolates may be diazotrophs based not only on their ability to grow in N-free medium and reduce acetylene to ethylene but also on the results from
15
N isotope dilution analysis and the finding that a
nifH
gene was PCR amplified. A comparison of the
nifH
sequences from the various isolates showed that they are closely related to
nifH
from
Frankia
; the similarity was 84 to 98% depending on the host specificity group. An analysis of complete 16S rRNA gene sequences demonstrated that the two strains analyzed in detail are most closely related to actinobacteria in the
Thermomonosporaceae
and the
Micromonosporaceae
.
Legionella
Species Diversity in an Acidic Biofilm Community in Yellowstone National Park
Authors: Sheehan Kathy B. , Henson Joan M. , Ferris Michael J.
Published: January 2005

Legionella
species are frequently detected in aquatic environments, but their occurrence in extreme, acidic, geothermal habitats has not been explored with cultivation-independent methods. We investigated a predominately eukaryotic algal mat community in a pH 2.7 geothermal stream in Yellowstone National Park for the presence of
Legionella
and potential host amoebae. Our analyses, using PCR amplification with
Legionella
-specific primers targeting 16S rRNA genes, detected four known
Legionella
species, as well as
Legionella
sequences from species that are not represented in sequence databases, in mat samples and cultivated isolates. The nonrandom occurrence of sequences detected at lower (30°C) and higher (35 to 38°C) temperatures suggests that natural thermal gradients in the stream influence
Legionella
species distributions in this mat community. We detected only one sequence,
Legionella micdadei
, from cultivated isolates. We cultured and sequenced partial 18S rRNA gene regions from two potential hosts,
Acanthamoeba
and
Euglena
species.
Characterization of Ichthyocidal Activity of
Pfiesteria piscicida
: Dependence on the Dinospore Cell Density
Authors: Drgon Tomás , Saito Keiko , Gillevet Patrick M. , Sikaroodi Masoumeh , Whitaker Brent , Krupatkina Danara N. , Argemi Federico , Vasta Gerardo R.
Published: January 2005

The ichthyocidal activity of
Pfiesteria piscicida
dinospores was examined in an aquarium bioassay format by exposing fish to either
Pfiesteria
-containing environmental sediments or clonal
P. piscicida
. The presence of
Pfiesteria
spp. and the complexity of the microbial assemblage in the bioassay were assessed by molecular approaches. Cell-free water from bioassays that yielded significant fish mortality failed to show ichthyocidal activity. Histopathological examination of moribund and dead fish failed to reveal the skin lesions reported elsewhere. Fish larvae within “cages” of variable mesh sizes were killed in those where the pore size exceeded that of
Pfiesteria
dinospores. In vitro exposure of fish larvae to clonal
P. piscicida
indicated that fish mortality was directly proportional to the dinospore cell density. Dinospores clustered around the mouth, eyes, and operculi, suggesting that fish health may be affected by their direct interaction with skin, gill epithelia, or mucous surfaces. Molecular fingerprinting revealed the presence of a very diverse microbial community of bacteria, protists, and fungi within bioassay aquaria containing environmental sediments. Some components of the microbial community were identified as potential fish pathogens, preventing the rigorous identification of
Pfiesteria
spp. as the only cause of fish death. In summary, our results strongly suggest (i) that this aquarium bioassay format, which has been extensively reported in the literature, is unsuitable to accurately assess the ichthyocidal activity of
Pfiesteria
spp. and (ii) that the ichthyocidal activity of
Pfiesteria
spp. is mostly due to direct interactions of the zoospores with fish skin and gill epithelia rather than to soluble factors.
Biocidal Activity of Formaldehyde and Nonformaldehyde Biocides toward
Mycobacterium immunogenum
and
Pseudomonas fluorescens
in Pure and Mixed Suspensions in Synthetic Metalworking Fluid and Saline
Authors: Selvaraju Suresh B. , Khan Izhar U. H. , Yadav Jagjit S.
Published: January 2005

The microbicidal activity of four different biocides was studied in synthetic metalworking fluid (MWF) against
Mycobacterium immunogenum
, a suspected causative agent for hypersensitivity pneumonitis, and
Pseudomonas fluorescens
, a representative for the predominant gram-negative bacterial contaminants of MWF. The results indicated that
M. immunogenum
is more resistant than
P. fluorescens
to the tested formaldehyde-releasing biocides (Grotan and Bioban), isothiazolone (Kathon), and phenolic biocide (Preventol). Kathon was effective against mycobacteria at lower concentrations than the other three test biocides in MWF. In general, there was a marked increase in biocidal resistance of both the test organisms when present in MWF matrix compared to saline. Increased resistance of the two test organisms to biocides was observed when they were in a mixed suspension (1:1 ratio). The results indicate the protective effect of the MWF matrix against the action of commonly used biocides on the MWF-colonizing microbial species of occupational health significance, including mycobacteria.
Scarce Evidence of Yogurt Lactic Acid Bacteria in Human Feces after Daily Yogurt Consumption by Healthy Volunteers
Authors: del Campo Rosa , Bravo Daniel , Cantón Rafael , Ruiz-Garbajosa Patricia , García-Albiach Raimundo , Montesi-Libois Alejandra , Yuste Francisco-Javier , Abraira Victor , Baquero Fernando
Published: January 2005

In a double-blind prospective study including 114 healthy young volunteers, the presence in human feces of the yogurt organismsLactobacillus delbrueckiiandStreptococcus thermophilusafter repeated yogurt consumption (15 days) was analyzed by culture, specific PCR, and DNA hybridization of total fecal DNA. Detection of yogurt lactic acid bacteria in total fecal DNA by bacterial culture and PCR assay was consistently negative. DNA compatible with yogurt bacteria was found by hybridization experiments in only 10 (10.52%) of 96 individuals after consumption of fresh yogurt and in 2 (2.10%) of 96 individuals after consumption of pasteurized yogurt (P= 0.01).
Transcriptional Analysis of Genes Encoding Shiga Toxin 2 and Its Variants in
Escherichia coli
Authors: Zhang Wenlan , Bielaszewska Martina , Friedrich Alexander W. , Kuczius Thorsten , Karch Helge
Published: January 2005

Six of 37 non-O157
Escherichia coli
strains possessing Shiga toxin (Stx) 2 gene variant
stx
2d
or
stx
2e
secreted no detectable Stx. These isolates produced significantly less
stx
mRNA than Stx2d, Stx2e, Stx2c, or Stx2 secretors did. Standard screening procedures miss a significant subset of
E. coli
harboring
stx
2
variants.
Maturation by LctT Is Required for Biosynthesis of Full-Length Lantibiotic Lacticin 481
Authors: Uguen Patricia , Hindré Thomas , Didelot Sandrine , Marty Christel , Haras Dominique , Le Pennec Jean-Paul , Vallée-Réhel Karine , Dufour Alain
Published: January 2005

In lantibiotic lacticin 481 biosynthesis, LctT cleaves the precursor peptide and exports mature lantibiotic. Matrix-assisted laser desorption ionization-time of flight mass spectrometry revealed that a truncated form of lacticin 481 is produced in the absence of LctT or after cleavage site inactivation. Production of truncated lacticin 481 is 4-fold less efficient, and its specific activity is about 10-fold lower.
Molecular Diversity and Characterization of Tetracycline-Resistant
Staphylococcus aureus
Isolates from a Poultry Processing Plant
Authors: Huys Geert , D'Haene Klaas , Van Eldere Johan , von Holy Alexander , Swings Jean
Published: January 2005

DNA fingerprinting and molecular characterization showed that the tetracycline-resistant
Staphylococcus aureus
population of a South African poultry processing plant comprised one or possibly several
tet
(K)-containing endemic clones that contaminated chicken and machinery surfaces at all sampled processing stages. The
tet
(K) gene was transferable by filter mating to
S. aureus
recipient 80CR5 and was located on a pT181-like plasmid.
Use of
glnQ
as a Counterselectable Marker for Creation of Allelic Exchange Mutations in Group B Streptococci
Authors: Tamura Glen S. , Bratt Debra S. , Yim Harry H. , Nittayajarn Aphakorn
Published: January 2005

Efficient allelic exchange mutagenesis in group B streptococci (GBS) has been hampered by the lack of a counterselectable marker system. Growth inhibition of GBS by the glutamine analog gamma-glutamyl hydrazide requires
glnQ
. We have used this phenomenon to create a counterselectable marker system for efficient selection of allelic exchange mutants in GBS.
Discrimination Efficacy of Fecal Pollution Detection in Different Aquatic Habitats of a High-Altitude Tropical Country, Using Presumptive Coliforms,
Escherichia coli
, and
Clostridium perfringens
Spores
Authors: Byamukama Denis , Mach Robert L. , Kansiime Frank , Manafi Mohamad , Farnleitner Andreas H.
Published: January 2005

The performance of rapid and practicable techniques that presumptively identify total coliforms (TC), fecal coliforms (FC),
Escherichia coli
, and
Clostridium perfringens
spores (CP) by testing them on a pollution gradient in differing aquatic habitats in a high-altitude tropical country was evaluated during a 12-month period. Site selection was based on high and low anthropogenic influence criteria of paired sites including six spring, six stream, and four lakeshore sites spread over central and eastern parts of Uganda. Unlike the chemophysical water quality, which was water source type dependent (i.e., spring, lake, or stream), fecal indicators were associated with the anthropogenic influence status of the respective sites. A total of 79% of the total variability, including all the determined four bacteriological and five chemophysical parameters, could be assigned to either a pollution, a habitat, or a metabolic activity component by principal-component analysis. Bacteriological indicators revealed significant correlations to the pollution component, reflecting that anthropogenic contamination gradients were followed. Discrimination sensitivity analysis revealed high ability of
E. coli
to differentiate between high and low levels of anthropogenic influence. CP also showed a reasonable level of discrimination, although FC and TC were found to have worse discrimination efficacy. Nonpoint influence by soil erosion could not be detected during the study period by correlation analysis, although a theoretical contamination potential existed, as investigated soils in the immediate surroundings often contained relevant concentrations of fecal indicators. The outcome of this study indicates that rapid techniques for presumptive
E. coli
and CP determination may be reliable for fecal pollution monitoring in high-altitude tropical developing countries such as those of Eastern Africa.
Membrane Adsorption with Direct Cell Culture Combined with Reverse Transcription-PCR as a Fast Method for Identifying Enteroviruses from Sewage
Authors: Papaventsis D. , Siafakas N. , Markoulatos P. , Papageorgiou G. T. , Kourtis C. , Chatzichristou E. , Economou C. , Levidiotou S.
Published: January 2005

We present a new approach for the detection and identification of enteroviruses concentrated and isolated from sewage. Samples were collected from two study sites located at Nicosia and Limassol sewage treatment plants in Cyprus. Viruses were adsorbed to cellulose nitrate membrane filters, cultured directly from the membrane filters by using the VIRADEN method, and identified by reverse transcription-PCR, followed by 5′ untranslated region (5′-UTR) restriction fragment length polymorphism (RFLP) analysis and partial sequencing of the VP1 protein coding region. Initial subgrouping based on the HpaII restriction profile showed that all of the isolates except one belonged to the same genetic subcluster. Partial VP1 sequencing revealed that most isolates belonged to serotypes coxsackie B4 (42.5%) and coxsackie Α9 (30%), whereas coxsackie B2 (17.5%) and coxsackie B1 (3%) isolates were less frequently observed. One poliovirus type 2 isolate (2.5%) of vaccine origin was also found. The HpaII digests predicted the genetic subcluster for all isolates. They also accurately differentiated the isolates as nonpolio or polio isolates. This approach seems to be very promising for environmental surveillance of enterovirus circulation and epidemiology, with all of the significant effects that this entails for public health. Partial VP1 sequencing is efficient for molecular serotyping of enteroviruses, while 5′-UTR RFLP analysis with HpaII can also be considered an asset for the initial subclassification of enterovirus isolates.
Temperature-Driven Campylobacter Seasonality in England and Wales
Authors: Louis Valérie R. , Gillespie Iain A. , O'Brien Sarah J. , Russek-Cohen Estelle , Pearson Andrew D. , Colwell Rita R.
Published: January 2005

Campylobacter incidence in England and Wales between 1990 and 1999 was examined in conjunction with weather conditions. Over the 10-year interval, the average annual rate was determined to be 78.4 ± 15.0 cases per 100,000, with an upward trend. Rates were higher in males than in females, regardless of age, and highest in children less than 5 years old. Major regional differences were detected, with the highest rates in Wales and the southwest and the lowest in the southeast. The disease displayed a seasonal pattern, and increased campylobacter rates were found to be correlated with temperature. The most marked seasonal effect was observed for children under the age of 5. The seasonal pattern of campylobacter infections indicated a linkage with environmental factors rather than food sources. Therefore, public health interventions should not be restricted to food-borne approaches, and the epidemiology of the seasonal peak in human campylobacter infections may best be understood through studies in young children.
Clinical presentation and operative repair of hernia of Morgagni
Authors: Loong T P F , Kocher H M
Published: January 2005

A 77 year old woman who presented with an incarcerated hernia of Morgagni was successfully treated without complications. A Medline search (1996 to date) along with cross referencing was done to quantify the number of acute presentations in adults compared to children. Different investigating modalities—for example, lateral chest and abdominal radiography, contrast studies or, in difficult cases, computed tomography or magnetic resonance imaging—can be used to diagnose hernia of Morgagni. The favoured method of repair—laparotomy or laparoscopy—is also discussed. A total of 47 case reports on children and 93 case reports on adults were found. Fourteen percent of children (seven out of 47) presented acutely compared with 12% of adults (12 out of 93). Repair at laparotomy was the method of choice but if uncertain, laparoscopy would be a useful diagnostic tool before attempted repair. Laparoscopic repair was favoured in adults especially in non-acute cases.
Gilles de la Tourette’s syndrome and its impact in the UK
Authors: Stern J S , Burza S , Robertson M M
Published: January 2005

Gilles de la Tourette’s syndrome of chronic multiple motor and vocal tics is now acknowledged to be far more common than once thought, affecting up to 1% of schoolchildren with a wide range of severity. At the milder end of the spectrum the associated psychopathologies can in themselves impair social and educational functioning, in particular obsessive compulsive disorder and attention deficit hyperactivity disorder. Many patients with this condition are not being adequately served by health and education services in the UK. The epidemiology, clinical features, aetiological factors, and management of the syndrome are reviewed.
Antisense oligodeoxyribonucleotide as to the growth factor midkine suppresses neointima formation induced by balloon injury
Authors: Hayashi Kenji , Banno Hiroshi , Kadomatsu Kenji , Takei Yoshifumi , Komori Kimihiro , Muramatsu Takashi
Published: January 2005

Restenosis is the major clinical problem of angioplasty. We have previously shown that neointima formation is strikingly suppressed in midkine (MK)-deficient mice. Neointima formation is restored if MK protein is administrated to the deficient mice. MK is a heparin-binding growth factor and implicated in the migration of inflammatory cells and vascular smooth muscle cells. Consistently, the suppression of neointima formation in the deficient mice is accompanied by suppression of recruitment of inflammatory cells into the vascular wall. Here, we evaluated the potential of MK antisense oligodeoxyribonucleotide (ODN) for the prevention of restenosis. We cloned the cDNA of rabbit MK, which showed a strongly conserved sequence in mammals. The balloon injury induced MK expression, with the maximum level occurring 7–14 days after angioplasty, in the rabbit carotid artery. Two antisense ODNs suppressed the production of MK in a rabbit kidney cell line, RK13 cells, one of which was then transfected into the arterial wall by means of lipofection immediately after balloon treatment. The antisense ODN suppressed MK induction in vivo and consequently suppressed neointima formation to 60% of the control level. These results suggest that MK is a candidate molecular target for the therapy for vascular restenosis.
Angiotensin II-induced Akt activation is mediated by metabolites of arachidonic acid generated by CaMKII-stimulated Ca2+-dependent phospholipase A2
Authors: Li Fang , Malik Kafait U.
Published: January 2005

Angiotensin II (ANG II) promotes vascular smooth muscle cell (VSMC) growth, stimulates Ca2+-calmodulin (CaM)-dependent kinase II (CaMKII), and activates cytosolic Ca2+-dependent phospholipase A2(cPLA2), which releases arachidonic acid (AA). ANG II also generates H2O2and activates Akt, which have been implicated in ANG II actions in VSMC. This study was conducted to investigate the relationship of these signaling molecules to Akt activation in rat aortic VSMC. ANG II increased Akt activity, as measured by its phosphorylation at serine-473. ANG II (200 nM)-induced Akt phosphorylation was decreased by extracellular Ca2+depletion and calcium chelator EGTA and inhibitors of CaM [ N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide] and CaMKII {(2-[ N-(2-hydroxyethyl)]- N-(4-me-thoxybenzenesulfonyl)]amino- N-(4-chlorocinnamyl)- N-methylbenzyl-amine)}. cPLA2inhibitor pyrrolidine-1, antisense oligonucleotide, and retroviral small interfering RNA also attenuated ANG II-induced Akt phosphorylation. AA increased Akt phosphorylation, and AA metabolism inhibitor 5,8,11,14-eicosatetraynoic acid (ETYA) blocked ANG II- and AA-induced Akt phosphorylation (199.03 ± 27.91% with ANG II and 110.18 ± 22.40% with ETYA + ANG II; 405.00 ± 86.22% with AA and 153.97 ± 63.26% with ETYA + AA). Inhibitors of lipoxygenase (cinnamyl-3,4-dihydroxy-α-cyanocinnamate) and cytochrome P-450 (ketoconazole and 17-octadecynoic acid), but not cyclooxygenase (indomethacin), attenuated ANG II- and AA-induced Akt phosphorylation. Furthermore, 5( S)-, 12( S)-, 15( S)-, and 20-hydroxyeicosatetraenoic acids and 5,6-, 11,12-, and 14,15-epoxyeicosatrienoic acids increased Akt phosphorylation. Catalase inhibited ANG II-increased H2O2production but not Akt phosphorylation. Oleic acid, which also increased H2O2production, did not cause Akt phosphorylation. These data suggest that ANG II-induced Akt activation in VSMC is mediated by AA metabolites, most likely generated via lipoxygenase and cytochrome P-450 consequent to AA released by CaMKII-activated cPLA2and independent of H2O2production.
Role of dual-site phospholamban phosphorylation in intermittent hypoxia-induced cardioprotection against ischemia-reperfusion injury
Authors: Xie Yan , Zhu Yi , Zhu Wei-Zhong , Chen Le , Zhou Zhao-Nian , Yuan Wen-Jun , Yang Huang-Tian
Published: January 2005

Cardioprotection by intermittent high-altitude (IHA) hypoxia against ischemia-reperfusion (I/R) injury is associated with Ca2+overload reduction. Phospholamban (PLB) phosphorylation relieves cardiac sarcoplasmic reticulum (SR) Ca2+-pump ATPase, a critical regulator in intracellular Ca2+cycling, from inhibition. To test the hypothesis that IHA hypoxia increases PLB phosphorylation and that such an effect plays a role in cardioprotection, we compared the time-dependent changes in the PLB phosphorylation at Ser16(PKA site) and Thr17(CaMKII site) in perfused normoxic rat hearts with those in IHA hypoxic rat hearts submitted to 30-min ischemia (I30) followed by 30-min reperfusion (R30). IHA hypoxia improved postischemic contractile recovery, reduced the maximum extent of ischemic contracture, and attenuated I/R-induced depression in Ca2+-pump ATPase activity. Although the PLB protein levels remained constant during I/R in both groups, Ser16phosphorylation increased at I30 and 1 min of reperfusion (R1) but decreased at R30 in normoxic hearts. IHA hypoxia upregulated the increase further at I30 and R1. Thr17phosphorylation decreased at I30, R1, and R30 in normoxic hearts, but IHA hypoxia attenuated the depression at R1 and R30. Moreover, PKA inhibitor H89 abolished IHA hypoxia-induced increase in Ser16phosphorylation, Ca2+-pump ATPase activity, and the recovery of cardiac performance after ischemia. CaMKII inhibitor KN-93 also abolished the beneficial effects of IHA hypoxia on Thr17phosphorylation, Ca2+-pump ATPase activity, and the postischemic contractile recovery. These findings indicate that IHA hypoxia mitigates I/R-induced depression in SR Ca2+-pump ATPase activity by upregulating dual-site PLB phosphorylation, which may consequently contribute to IHA hypoxia-induced cardioprotection against I/R injury.
Parotid secretory protein is an HDL-associated protein with anticandidal activity
Authors: Khovidhunkit Weerapan , Hachem Jean Pierre , Medzihradszky Katalin F. , Duchateau Philippe N. , Shigenaga Judy K. , Moser Arthur H. , Movsesyan Irina , Naya-Vigne Josefina , Kane John P. , Feingold Kenneth R. , Grunfeld Carl
Published: January 2005

High-density lipoprotein (HDL) is part of innate immunity, protecting against infection and inflammation. Using a proteomic approach, we identified an amino acid sequence in a hamster HDL protein that showed homology to rat and mouse parotid secretory protein (PSP), a salivary protein secreted from the parotid glands. We cloned the cDNA encoding a putative hamster homolog of rat and mouse PSP. Searches for conserved domains of the protein showed that the COOH terminus of hamster PSP contains a region homologous to the NH2termini of a family of HDL-associated proteins, including LPS-binding protein, cholesteryl ester transfer protein, and phospholipid transfer protein. In mice, PSP was also associated with HDL but was not detected in very-low-density lipoprotein, low-density lipoprotein, or lipoprotein-deficient sera. In addition to salivary glands, we found that PSP mRNA was expressed in lung, testis, and ovary. The level of PSP in HDL was increased after endotoxin injection in hamsters, but not in mice. Recombinant PSP inhibits growth of Candida albicans in culture. In summary, our results showed that PSP is a novel anticandidal protein associated with HDL.
Increased dietary sodium inhibits baroreflex-induced bradycardia during acute sodium loading
Authors: Bealer Steven L.
Published: January 2005

The present study investigated the effects of increased dietary sodium on the modification of cardiac baroreflex responses induced by acute sodium loading. Changes in blood pressure and heart rate during intravenous phenylephrine and nitroprusside administration were compared using a four-parameter sigmoid logistic function before and after a 30-min infusion of 0.6 or 1.0 M NaCl in conscious male Sprague-Dawley rats consuming only tap water (Tap) or isotonic saline (Iso) for 2–3 wk. In Tap animals, infusion of 1.0 M NaCl increased the baroreflex-induced heart rate minimum, reduced heart rate range, and increased the operating blood pressure. In contrast, infusion of 0.6 M NaCl in Tap rats reduced both heart rate minimum and maximum. However, infusion of 0.6 M NaCl in Iso animals produced responses similar to that shown in Tap rats infused with 1.0 M NaCl. In addition, the decreased heart rate minimum in Tap rats after infusion of 0.6 M NaCl was prevented by intravenous administration of a vasopressin V1-receptor antagonist. Furthermore, cardiac parasympathetic responses were similar in Tap and Iso rats before and after 0.6 M NaCl infusion. However, in animals receiving intravenous atropine, 0.6 M NaCl decreased heart rate minimum and maximum in Tap but did not alter the response parameters in Iso rats. These results demonstrate that the facilitation of cardiac baroreflex responses normally observed during moderate sodium loading is mediated by vasopressin and that increased dietary sodium ingestion reverses this facilitation by reducing sympathetic nervous system withdrawal.
Aortic banding in rat as a model to investigate malnutrition associated with heart failure
Authors: Héliès-Toussaint Cécile , Moinard Christophe , Rasmusen Carole , Tabbi-Anneni Imène , Cynober Luc , Grynberg Alain
Published: January 2005

Heart failure is a severe pathology, which has displayed a dramatic increase in the occurrence of patients with chronic heart disease in developed countries, as a result of increases in the population's average age and in survival time. This pathology is associated with severe malnutrition, which worsens the prognosis. Although the cachexia associated with chronic heart failure is a well-known complication, there is no reference animal model of malnutrition related to heart failure. This study was designed to evaluate the nutritional status of rats in a model of loss of cardiac function obtained by ascending aortic banding. Cardiac overload led to the development of cardiac hypertrophy, which decompensates to heart failure, with increased brain natriuretic peptide levels. The rats displayed hepatic dysfunction and an associated renal hypotrophy and renal failure, evidenced by the alteration in renal function markers such as citrullinemia, creatininemia, and uremia. Malnutrition has been evidenced by the alteration of protein and amino acid metabolism. A muscular atrophy with decreased protein content and increased amino acid concentrations in both plasma and muscle was observed. These rats with heart failure displayed a multiorgan failure and malnutrition, which reflected the clinical situation of human chronic heart failure.
Brain-derived adrenomedullin controls blood volume through the regulation of arginine vasopressin production and release
Authors: Taylor Meghan M. , Baker Jennifer R. , Samson Willis K.
Published: January 2005

Central nervous system-derived adrenomedullin (AM) has been shown to be a physiological regulator of thirst. Administration of AM into the lateral ventricle of the brain attenuated water intake, whereas a decrease in endogenous AM, induced by an AM-specific ribozyme, led to exaggerated water intake. We hypothesized that central AM may control fluid homeostasis, in part by regulating plasma arginine vasopressin (AVP) levels. To test this hypothesis, AM or a ribozyme specific to AM was administered intracerebroventricularly, and alterations in plasma AVP concentrations were examined under basal and stimulated (hypovolemic) conditions. Additionally, we examined changes in blood volume, kidney function, and plasma electrolyte and protein levels, as well as changes in plasma aldosterone concentrations. Intracerebroventricular administration of AM increased plasma AVP levels, whereas AM ribozyme treatment led to decreased plasma AVP levels under stimulated conditions. During hypovolemic challenges, AM ribozyme treatment led to an increased loss of plasma volume compared with control animals. Although overall plasma osmolality did not differ between treatment groups during hypovolemia, aldosterone levels were significantly higher and, consequently, plasma potassium concentrations were lower in AM ribozyme-treated rats than in controls. These data suggest that brain-derived AM is a physiological regulator of vasopressin secretion and, thereby, fluid homeostasis.
Full-length sucrose-formulated recombinant factor VIII for treatment of previously untreated or minimally treated young children with severe haemophilia A
Authors: Gill Joan , Rothschild Chantal , Manco-Johnson Marilyn , Lusher Jeanne , Kellermann Elke , Gorina Eduard , Larson Peter , Kreuz Wolfhart ,   and the International Kogenate-FS Study Group
Published: January 2005

The safety and efficacy of a full-length sucrose-formulated recombinant factor VIII product (rFVIII-FS; KogenateFS; Kogenate Bayer) was evaluated in previously untreated (PUPs) and minimally treated (MTP) patients with severe haemophilia A (FVIII < 2%). Patients (37 PUPs; 24 MTPs) aged 0.1–25.7 months were treated with rFVIII-FS for a cumulative of 9,141 exposure days (EDs), median 114 EDs (range 4–478), on prophylactic or on-demand therapy. Eighty-nine percent of all treated bleeding episodes were successfully treated with 1 (74%) or 2 (15%) infusions. Clinical response to first infusion for each bleeding episode was rated as ‘excellent’ in 58%, or ‘good’ in 33%, of all cases. Recombinant FVIII-FS was used in 27 surgical procedures, mainly catheter implantations, which were all conducted without bleeding complications. FVIII recovery mean values (~2%/kg/ IU) were as expected for any licensed FVIII concentrate. FVIII neutralizing antibody formation was 15% (9/60). Aside from inhibitor formation, three adverse events were rated as ‘at least possibly drug-related’ for a total drug-related adverse event rate of 0.14%. No viral seroconversions were observed. Overall, excellent safety and efficacy were demonstrated with rFVIII-FS for therapy of young children with severe haemophilia A.
CD63 modulates spreading and tyrosine phosphorylation of platelets on immobilized fibrinogen
Authors: McMillan-Ward Eileen M. , Israels Sara J.
Published: January 2005

CD63 is a member of the tetraspanin superfamily of integral membrane proteins. Present on a variety of cells, tetraspanins can form lateral associations with integrins and may act as ‘organizers’ of multimolecular networks that modulate integrinmediated signaling, cell morphology, motility and migration. In resting platelets, CD63 is present on the membranes of dense granules and lysosomes but relocates to the plasma membrane following platelet activation and exocytosis where it associates with the platelet integrin α IIbβ 3-CD9 complex and with the actin cytoskeleton in an α IIbβ 3-dependent manner. D545, a monoclonal antibody directed at the second extracellular loop of CD63,was used to investigate the role of CD63 in platelet adhesion, spreading and tyrosine phosphorylation. Using immunofluorescence microscopy and confocal imaging, we have demonstrated that D545 does not alter adhesion of platelets to immobilized fibrinogen, but instead platelet spreading. In the presence of buffer or non-specific mouse IgG, activated platelets showed fully spread morphology, F-actin reorganization, redistribution of vinculin and extensive tyrosine phosphorylation, all of which were inhibited by D545. D545 also inhibited the phosphorylation of focal adhesion kinase in thrombin-activated adherent platelets. These results suggest that CD63 may modulate α IIbβ 3-dependent cytoskeletal reorganization. To identify signaling enzymes associated with CD63 that could affect this pathway, lipid kinase assays were performed on D545 immunoprecipitates. CD63 co-immunoprecipitated with a lipid kinase which, on the basis of enzymatic properties(stimulated by nonionic detergents, inhibited by adenosine), is consistent with PI 4-kinase type II. The CD63-PI 4-kinase complex was not activation- dependent as the constituents were co-purified from both resting and activated platelets. The linkage of CD63 with PI 4-kinase may result in the recruitment of this signaling enzyme to specific membrane locations in the platelet where it influences phosphoinositide-dependent signaling and platelet spreading.
Effects of human cytomegalovirus infection on the coagulation system
Authors: Gerdes Victor , Büller Harry , Squizzato Alessandro
Published: January 2005

Pathophysiological mechanisms of acute vascular thrombosis are not fully understood. It has been suggested that different infectious pathogens are responsible agents of thrombotic disorders. The infection hypothesis is supported by an increasing number of reports on the interaction between acute infection and coagulation. Cytomegalovirus (CMV) is supposed to play an important role in apparently unprovoked thrombosis. We reviewed all human in vitro and in vivo studies on the influence of human CMV infection on the coagulation system, as well as all case reports of acute thrombosis during acute human CMV infection. In the published literature there is mounting evidence that human CMV may play a role in thrombotic disorders. Definitive conclusions, however, cannot be drawn, although the in vitro studies are convincing and offer insight in the pathogenesis.
The study of anaemia-related haemostasis impairment in haemodialysis patients by in vitro closure time test
Authors: Sabovic Miso , Salobir Barbara , Ponikvar Jadranka Buturovic , Cernelc Peter , Lavre Janez , Vujkovac Bojan , Zupan Irena Preloznik
Published: January 2005

It is known that anaemia in haemodialysis patients could contribute to haemostasis impairment. However, the precise relation between the degree of anaemia and the degree of haemostasis impairment is not known, nor the optimal level of hematocrit above which anaemia no longer disturbs haemostasis. Our study addresses these clinically relevant questions by employing in vitro closure time test, a new method in which the process of platelet adhesion and aggregation following vascular injury is simulated in vitro in samples of whole blood. We studied 63 haemodialysis patients, with 30 age-matched, healthy controls. Results show that patients with hematocrit below 0.32 (N=28) had significantly impaired primary haemostasis, in contrast to patients with hematocrit above 0.32 (N=35), as measured by both types of closure time test. A significant negative association was found between hematocrit values and closure time (CEPI cartridges: rho=–0.41, p <0.001; CADP cartridges: rho =–0.47, p <0.001). A multiple logistic regression model for predicting prolonged closure time confirmed this finding. Nonparametric curve fitting enabled estimation of the level of hematocrit at which the values of in vitro closure time in haemodialysis patients do not differ from those in the controls at approximately 0.35. ROC analysis confirmed this to be the optimal threshold for predicting prolonged closure time for both cartridges. By using in vitro closure time test, we confirmed that anaemia correlates with the severity of haemostasis impairment. We estimated the target level of hematocrit above which anaemia no longer affects haemostasis to be about 0.35.These new results (and new assay) appear to have clinical value for treating haemodialysis patients.
Crotalid venom vascular endothelial growth factors has preferential affinity for VEGFR-1
Authors: Chen Yuh-Ling , Hong Tse-Ming , Tsai Shu-Huei , Tsai Inn-Ho
Published: January 2005

Pm-VEGF, a novel member ofVEGF family from the venom gland of Taiwan habu (Protobothrops mucrosquamatu), is a disulfidelinked homodimer with 119 amino acid residues. Recombinant fusion Pm-VEGF was expressed in Escherichia coli, purified and refolded. Surface plasmon resonance was used to determine its binding kinetics toVEGF-receptors (VEGFR). Relative to human VEGF165, the binding affinity of Pm-VEGF to the VEGFR-1 was 1.7-fold higher while affinity to the VEGFR-2 was 17-fold lower. But it did not bind theVEGFR-3 or neuropilin-1. Pm-VEGF promoted the proliferation and tissue factor production of endothelial cells, the neovascularization in the chicken chorioallantoic membrane, and increased vascular permeability. It also stimulated tissue-factor production and human monocyte chemotaxis, in accord with its specificity for VEGFR-1. Structural comparison among VEGF-proteins from various viper venoms revealed that the two subfamilies of vipers (Crotalinae and Viperinae) have evolved with distinct receptor-specificities for VEGFR-1 and VEGFR-2, respectively. Discussion on structureactivity relationships of the VEGFs further provided insight into residues important for the receptor-binding and specificities.
Asymptomatic postoperative deep vein thrombosis and the development of postthrombotic syndrome
Authors: Jorgensen Lars N. , Crawford Michael , Wille-Jørgensen Peer
Published: January 2005

Perioperative antithrombotic clinical regimens have reduced the incidence of postoperative deep venous thrombosis (DVT). Long-term effects of asymptomatic postoperative DVT have been studied in a number of clinical trials and the present review describes the clinical significance of asymptomatic postoperative DVT regarding the possible development of postthrombotic syndrome (PTS).We performed a systematic review of reference databases focusing upon studies including patients suspected of having postoperative DVT and reporting subsequent cases of PTS at the end of a well-defined follow-up period. The included studies were stratified according to type of screening method and applied statistics. Over-all evaluation included metaanalyses based upon the Cochrane software package. The overall relative risk of developing PTS was 1.58 (95% confidence intervals: 1.24 – 2.02) in patients suffering from asymptomatic DVT as compared to patients without DVT ( p < 0.0005).In conclusion, asymptomatic postoperative DVT is associated with an increased risk of late development of PTS. The finding emphasizes that postoperative DVT, diagnosed by means of well-defined objective measures, remains the correct scientific endpoint in trials evaluating the efficacy of preoperative antithrombotic treatment regimens.
The factor VIII D1241E polymorphism is associated with decreased factor VIII activity and not with activated protein C resistance levels
Authors: Scanavini Daniela , Legnani Cristina , Lunghi Barbara , Mingozzi Federico , Palareti Gualtiero , Bernardi Francesco
Published: January 2005

Elevated factor VIII (FVIII) levels are a recognized risk factor for venous thrombosis. Recently, family studies suggested that the G allele of the 3951C/G (D1241E) FVIII polymorphism is associated to lower FVIII activity. We investigated in case-control studies both biological effects (FVIII levels and activated protein C sensitivity ratio) and clinical associations (venous thromboembolism) of the D1241E change. Among 145 healthy and 150 thrombotic women, not carriers of known thrombophilic defects, the 1241E allele was associated with 11% reduced (t-test, P< 0.05) FVIII levels. The effect on activated protein C sensitivity ratio was not statistically significant. Carriership of the 1241E allele, potentially conferring protection from thrombosis, was found in 22.8% of controls and in 15.3% of cases. In an additional cohort of factor V Leiden carriers (n=283), carriership of the 1241E allele was 25.2% among 143 asymptomatic subjects and 17.1% among 140 thrombotic patients. Our data do not indicate a specific interaction with factor V Leiden. These genotype distributions suggest a mild protective effect from venous thrombosis conferred by 1241E FVIII, masked by other genetic and/or environmental components, and detectable only in very large population studies. Our findings point toward the presence of genetic determinant of coagulation factor levels with a biologically significant role, but with a poor predictive value to estimate thrombotic risk beyond established risk factors.
Trends in Fatal and Nonfatal Strokes Among Persons Aged 35 to ≥85 Years During 1991–2002 in Finland
Authors: Pajunen Pia , Pääkkönen Rauni , Hämäläinen Helena , Keskimäki Ilmo , Laatikainen Tiina , Niemi Marja , Rintanen Hannu , Salomaa Veikko
Published: January 2005

Background and Purpose—

Declining trends in the incidence and mortality of stroke have been observed in Finland since the beginning of the 1980s until 1997. In this study we analyzed the trends in fatal and nonfatal strokes in Finland during 1991–2002.

Methods—

The Finnish Hospital Discharge Register was linked to the National Causes of Death Register to produce a Cardiovascular Disease Register, which includes data on 410 760 cerebrovascular events (
International Statistical Classification of Diseases, 10th Revision
[ICD-10] codes I60–I69) in patients aged ≥35 years in 1991–2002.

Results—

Age-standardized incidence of first-ever stroke (ICD-10 codes I60–I64, excluding I63.6) per 100 000 persons declined during 1991–2002 annually by 2.2% (95% CI, −2.4% to −1.9%) among men and 2.5% (−2.8% to −2.2%) among women aged 35 to 74 years. In patients aged 75 to 84 years, the change in the incidence of first-ever stroke was −2.6% per year (−3.0% to −2.2%) among men and −3.2% per year (−3.5% to −2.9%) among women. A similar trend was observed also in the oldest age group, in patients aged ≥85 years. Among patients aged 35 to 74 years, the 28-day case fatality of first-ever stroke declined annually by 3.2% (−3.9% to −2.5%) among men and by 3.0% (−3.8% to −2.2%) among women. A significant decrease was found in the 28-day case fatalities of all subtypes of stroke in this age group.

Conclusions—

The favorable development in stroke incidence, mortality, and case-fatality has continued in Finland during 1991–2002.