bluuebunny/crossref_metadata_2025 huggingface dataset:
Argyrophilic grain disease presenting with frontotemporal dementia: A neuropsychological and pathological study of an autopsied case with presenile onset
Authors: Ishihara Kenji , Araki Shigeo , Ihori Nami , Shiota Jun‐ichi , Kawamura Mitsuru , Yoshida Mari , Hashizume Yoshio , Nakano Imaharu
Published: April 2005

A right‐handed Japanese man with no consanguinity exhibited personality changes, speech disorder and abnormal behaviors, such as stereotypical, running‐away, environment‐dependent, and going‐my‐way behaviors, since the age of 49 years. At age 52 years, neuropsychological examination revealed frontal lobe dysfunctions, mild memory impairment, and transcortical sensory aphasia. MRI showed symmetrical severe atrophy of the anterior part of the temporal and frontal lobes. The clinical diagnosis was FTD. He died at age 54 years after a clinical illness of approximately 5 years. Numerous argyrophilic grains were observed throughout the limbic system, temporal lobe, frontal lobe and brainstem. In addition, there were many tau‐positive neurons and glial cells. These findings are all compatible with argyrophilic grain disease (AGD). Our case, however, is atypical AGD because of the young age of onset of the disease and sharply circumscribed cortical atrophy exhibiting severe neuronal loss and gliosis. Our case, together with some other similar cases of atypical AGD, gives rise to the possibility that this type of AGD would constitute a part of pathological background of FTD.
The monetary approach to exchange rates in the CEECs1
Authors: Crespo‐Cuaresma Jesús , Fidrmuc Jarko , MacDonald Ronald
Published: April 2005

A panel dataset for six Central and Eastern European countries (Czech Republic, Hungary, Poland, Romania, Slovakia and Slovenia) is used to estimate the monetary exchange rate model with panel cointegration methods, including the Pooled Mean Group estimator, the Fully Modified Least Square estimator and the Dynamic Least Square estimator. The monetary model is able to convincingly explain the long‐run exchange rate relationships of a group of CEECs, particularly when this is supplemented by a Balassa–Samuelson effect. Our estimated long‐run monetary equations are used to compute equilibrium exchange rates. Finally, we discuss the implications for the accession of selected countries to the European Economic and Monetary Union.
Dialyzer reactions in a patient switching from peritoneal dialysis to hemodialysis
Authors: Yang Robert C. , Lindsay Robert M.
Published: April 2005

Many terms have been used to describe the collection of signs and symptoms triggered by the initial use of dialyzers. These reactions can be divided into Type A (hypersensitivity reactions, with the incidence of 4/100,000) and Type B (nonspecific reactions, incidence 3–5/100). Many different mechanisms have been postulated, including complement activation, pulmonary leukostasis, hypersensitivity to ethylene oxide, interaction between the AN69 membrane and angiotensin‐converting enzyme inhibitors, and dialysate contamination. An unusual case of dialyzer reactions is presented here, involving a patient who had to discontinue peritoneal dialysis when she was admitted with fungal peritonitis. Upon initiation of hemodialysis, she experienced dyspnea and burning sensation and demonstrated significant leukopenia, thrombocytopenia, and oxygen desaturation. These reactions persisted despite double‐rinsing of the dialyzers and the use of several different dialyzers with synthetic membranes (polysulfone and AN69), and a variety of sterilization methods (electron beam and gamma radiation). In the end, a simple measure was found to be effective in preventing further dialyzer reactions in this fascinating case.
Considerations in the nutritional management of patients with acute renal failure
Authors: Strejc Jill M.
Published: April 2005

Despite improvements in medical and dialytic therapies, mortality rates for patients with complicated acute renal failure (ARF) remains tragically high—above 50%. Mortality rates also remain persistently high in patients with ARF and preexisting or hospital‐acquired malnutrition. ARF causes significant changes in substrate utilization largely because of the metabolic consequences of acute uremia compounded by underlying stress from acute illness. Alterations in protein or amino acid, carbohydrate, and lipid metabolism as well as fluid, electrolyte, and acid–base balance need to be considered when providing nutritional therapy in patients with ARF. Also, the degree of renal impairment, which influences the need for renal replacement therapy (RRT), impacts nutritional requirements. As medical management is becoming highly aggressive in treating ARF with RRT, the ability to provide adequate nutrition is enhanced; however, no consensus on optimal caloric and macro‐/micronutrient requirements is available. More current research is required to clarify nutritional needs of this patient population. Nevertheless, individualizing nutrition care and integrating nutritional therapies within a team setting is essential in providing optimal patient care in the presence of ARF.
Chronic viral hepatitis in hemodialysis patients
Authors: Tang Sydney , Lai Kar Neng
Published: April 2005

Ever since the first outbreaks of hepatitis in hemodialysis units in the late 1960s, a number of hepatotropic viruses transmitted by blood and other body fluids have been identified. This review summarizes the current state of knowledge regarding these blood‐borne agents from an epidemiologic and preventive perspective. Data source and study selection were obtained from research and review articles related to the epidemiology of viral hepatitis in hemodialysis and indexed on Medline and Embase from 1965 to 2004. Hepatitis B virus (HBV) was the first significant hepatotropic virus to be identified in hemodialysis centers. HBV infection has been effectively controlled by active vaccination, screening of blood donors, the use of erythropoietin, and segregation of HBV carriers. To date, HBV remains an important cause of morbidity in endemic areas. Hepatitis delta virus is a defective virus that can only infect HBV‐positive individuals. Hepatitis C virus is the most significant cause of non‐A, non‐B hepatitis and is mainly transmitted by blood transfusion. The introduction in 1990 of routine screening of blood donors for HCV contributed significantly to the control of HCV transmission. An effective HCV vaccine remains an unsolved challenge, however. Pegylation of interferon‐α has made it possible to treat HCV‐positive dialysis patients. Unexplained sporadic outbreaks of hepatitis by the mid‐1990s prompted the discovery of hepatitis G virus and hepatitis GB virus C in 1995 and the TT virus in 1997. Although epidemiologic analyses revealed high prevalence rates of both viruses in the hemodialysis population, their exact role in liver disease has yet to be determined. The vigilant observation of guidelines on universal precaution and regular virologic testing are the cornerstones of the effective control of chronic hepatitis in the setting of hemodialysis.
Short and long alteplase dwells in dysfunctional hemodialysis catheters
Authors: Macrae Jennifer Marie , Loh Gabriel , Djurdjev Ognjenka , Shalansky Steven , Werb Ron , Levin Adeera , Kiaii Mercedeh
Published: April 2005

Background:  Hemodialysis catheter dysfunction (CD) is the inability to attain adequate blood pump speeds (BPS) and is attributed to thrombus or catheter malposition; alteplase (TPA) is often given in a variety of dwell times to treat CD. The purpose of this study was to determine if TPA dwell time affects short‐ or long‐term catheter patency rates.

Methods:  Sixty hemodialysis (HD) patients with CD, as defined by BPS of < 250 mL/min, were randomized to receive either 1‐ or > 48‐hr (to subsequent HD run) TPA dwell. The primary outcomes were catheter patency (BPS of > 250 mL/min) at the subsequent HD run and catheter patency at 2 weeks. The secondary outcome was the time from study entry to the next catheter intervention (including subsequent TPA installation).

Results:  After TPA installation, a 78% overall catheter patency rate was observed at the subsequent HD run, falling to 48% patency at 2 weeks. There is no statistically significant difference between the short and long TPA dwell groups for catheter patency at the subsequent HD run (76.9% vs. 79.4%) or at 2 weeks (42.3% vs. 52.9%). Multivariate analysis demonstrates that the use of TPA on two or more previous occasions is a predictor of TPA failure both at the subsequent HD run and at 2 weeks. TPA installation achieves a median catheter function time of only 14 days, after which CD reoccurs.

Conclusion:  This study demonstrates that although patency for the next HD run can be achieved with either short or long TPA dwell, neither is reliable in terms of long‐term patency. Strategies that employ TPA for CD are temporary and allow a 2‐week window during which more definitive therapies for HD access should be sought.
The marginal cost of satellite versus in‐center hemodialysis
Authors: Soroka Steven D. , Kiberd Bryce A. , Jacobs Philip
Published: April 2005

Background:  Despite increasing numbers of patients receiving hemodialysis in satellite units (SHD), the economic aspects have not been widely explored. A cost analysis of SHD and in‐center hemodialysis (ICHD) from a societal perspective was performed to establish the efficiencies associated with shifting resources and patients from ICHD to SHD.

Methods:  Costs were classified as fixed or variable and placed into categories. The resources for operating a SHD unit are the sum of two components: total fixed costs (TFC) and average variable cost (AVC) times SHD patient volume (Q). Using the TFC of a specific‐sized SHD unit and the difference in AVC between ICHD and SHD the number of patients needed (Q) in the SHD unit for financial viability was determined. The formula TFC = (AVCICHD − AVCSHD) X Q was used to determine the number of patients (Q) needed in a specific‐sized SHD unit such that the yearly cost of SHD treatment would be the same as ICHD treatment.

Results:  Our results show that SHD fixed costs can be fully offset if the volume of SHD patients is seven per year in a six‐station unit. SHD costs were lower for nursing and physician fees. Therefore, ICHD care variable costs were $11,374 more per patient year. SHD patients would also have lower travel costs, a mean cost saving of $12,364 per year.

Conclusion:  SHD can result in significant savings both to the health‐care system and to patients. Using the cost categories and formula presented, the number of patients needed in a specific‐sized satellite unit to realize cost savings was determined for our program. We found that these savings can offset the fixed investment needed to operate a SHD unit at modest patient volumes.
Phosphorus‐enriched hemodialysis during pregnancy: Two case reports
Authors: Hussain Syed , Savin Virginia , Piering Walter , Tomasi Jane , Blumenthal Samuel
Published: April 2005

Successful pregnancy leading to delivery of a viable infant is an uncommon occurrence either in women with established renal disease or in those with renal failure requiring chronic dialytic treatment. The frequency of conception in patients with renal failure has increased, however, and the outcome of such pregnancies has improved over the past 32 years. Current guidelines for dialysis in pregnant women include prolonged dialysis times, generally 20 or more hours per week. This extensive dialysis regimen often results in a decrease in the serum inorganic phosphorus levels, with possible detrimental effects to the health of the mother and the unborn child. In this article, we report the successful multidisciplinary management of two pregnant women with end‐stage renal disease, both of whom developed hypophosphatemia after initiation of intensive hemodialysis. Sodium phosphate salts were added to the dialysate of each patient and this addition successfully corrected the decrease in serum inorganic phosphate concentration. One patient was able to carry the pregnancy for 28 weeks with delivery of a healthy 1260‐g infant. The pregnancy of the second patient ended at 25 weeks of gestation with delivery of a nonviable infant.
Invertebrate models of Alzheimer's disease
Authors: Link C. D.
Published: April 2005

The intensely studied model organisms Caenorhabditis elegans and Drosophila melanogaster have been employed to study a number of neurodegenerative diseases, including Alzheimer's disease (AD). Although worms and flies are phylogenetically distant from humans, results of both classic genetic analyses and transgenic manipulation of these invertebrates suggest they are valid models for at least some aspects of AD. This review describes the rationale for AD‐relevant studies in worms and flies and discusses both what has been learned from these studies and what may be discovered in the future.
Genetic and molecular aspects of Alzheimer's disease shed light on new mechanisms of transcriptional regulation
Authors: Marambaud P. , Robakis N. K.
Published: April 2005

Rapid advances made in biological research aimed at understanding the molecular basis of the pathogenesis of Alzheimer's disease have led to the characterization of a novel catalytic activity termed γ‐secretase. First described for its β‐amyloid‐producing function, γ‐secretase is now actively studied for its role in a novel signal transduction paradigm, which implicates cell‐surface receptor proteolysis and direct surface‐to‐nucleus signal transduction. γ‐Secretase targets numerous type I protein receptors involved in diverse functions ranging from normal development to neurodegeneration. In this Review we discuss how the study of the genetic and molecular aspects of Alzheimer's disease has revealed a dual role of γ‐secretase in transcriptional regulation and in the pathogenesis of familial Alzheimer's disease.
Behavioral phenotypes of amyloid‐based genetically modified mouse models of Alzheimer's disease
Authors: Kobayashi D. T. , Chen K. S.
Published: April 2005

Alzheimer's disease (AD) is the most common neurodegenerative affliction of the elderly, presenting with progressive memory loss and dementia and terminating with death. There have been significant advances in understanding the biology and subsequent diagnosis of AD; however, the furious pace of research has not yet translated into a disease‐modifying treatment. While scientific inquiry in AD is largely centered on identifying biological players and pathological mechanisms, the day‐to‐day realities of AD patients and their caregivers revolve around their steady and heartbreaking cognitive decline. In the past decade, AD research has been fundamentally transformed by the development of genetically modified animal models of amyloid‐driven neurodegeneration. These important in vivo models not only replicate some of the hallmark pathology of the disease, such as plaque‐like amyloid accumulations and astrocytic inflammation, but also some of the cognitive impairments relevant to AD. In this article, we will provide a detailed review of the behavioral and cognitive deficits present in several transgenic mouse models of AD and discuss their functional changes in response to experimental treatments.
EFFECT OF ENHANCED FLUORESCENT LIGHT ON ACCEPTABILITY OF MEAT CUTS
Authors: BARBUT S.
Published: April 2005

The effects of incandescent (INC) and two enhanced fluorescent lights: high‐spectrum (FL‐Hi Spec) and Chroma 50 (FL‐Chroma 50) on the appearance of fresh pork, chicken and beef meat were investigated. The color of all meats was more desirable (P < 0.05) when presented under INC and FL‐Hi Spec lights. The color used to describe pork meat presented under these two lights was mainly pink, but was more brown under FL‐Chroma 50. Relative luminance data, collected with a fiber optic probe connected to a photo diode array, demonstrated the reason for the lower amount of red in the FL‐Chroma 50 light source. The differences among the lights were more pronounced in the lighter pork and chicken cuts than in the darker beef cuts.
EFFECT OF CARRIER SOLVENT POLARITY ON SELECTIVE INCORPORATION OF EXOGENOUS δ‐TOCOPHEROL INTO MUSCLE MEMBRANES
Authors: RAGHAVAN SIVAKUMAR , HULTIN HERBERT O.
Published: April 2005

Selective incorporation of lipid‐soluble antioxidants into the oxidation‐sensitive membrane lipids may improve the shelf life. The optimal dielectric constant for δ‐tocopherol incorporation into a muscle membrane fraction when the tocopherol was added before the oil was approximately 21. This shifted to a value of about 27 when oil was present in the system before addition of the antioxidant. Tocopherol concentration in the oil fraction decreased continuously with an increase of dielectric constant from 17 to 32 when the antioxidant was added before the oil. When oil was present during antioxidant addition, no change in tocopherol concentration in the oil was observed except at the highest dielectric constant (32). The uptake of tocopherol was low in both the oil and membrane fractions when the carrier had a dielectric constant of 32 (propylene glycol). A higher concentration of δ‐tocopherol was achieved in the membrane fraction when the antioxidant was added to the system prior to the oil.
The Kinase Domain of Titin Controls Muscle Gene Expression and Protein Turnover
Authors: Lange Stephan , Xiang Fengqing , Yakovenko Andrey , Vihola Anna , Hackman Peter , Rostkova Elena , Kristensen Jakob , Brandmeier Birgit , Franzen Gereon , Hedberg Birgitta , Gunnarsson Lars Gunnar , Hughes Simon M. , Marchand Sylvie , Sejersen Thomas , Richard Isabelle , Edström Lars , Ehler Elisabeth , Udd Bjarne , Gautel Mathias
Published: April 2005

The giant sarcomeric protein titin contains a protein kinase domain (TK) ideally positioned to sense mechanical load. We identified a signaling complex where TK interacts with the zinc-finger protein nbr1 through a mechanically inducible conformation. Nbr1 targets the ubiquitin-associated p62/SQSTM1 to sarcomeres, and p62 in turn interacts with MuRF2, a muscle-specific RING-B-box E3 ligase and ligand of the transactivation domain of the serum response transcription factor (SRF). Nuclear translocation of MuRF2 was induced by mechanical inactivity and caused reduction of nuclear SRF and repression of transcription. A human mutation in the titin protein kinase domain causes hereditary muscle disease by disrupting this pathway.
Genome-Wide Transcriptional Profiling of the Steady-State Response of
Pseudomonas aeruginosa
to Hydrogen Peroxide
Authors: Salunkhe Prabhakar , Töpfer Tanja , Buer Jan , Tümmler Burkhard
Published: April 2005

The steady-state response of
Pseudomonas aeruginosa
to the oxidative-stress-generating agent hydrogen peroxide was analyzed by PAO1 transcriptome profiling. In total, 694, 411, and 237 genes were upregulated and 668, 576, and 468 genes were downregulated in
P. aeruginosa
strains TB, 892, and PAO1, respectively. The expression profiles of the two variants of the TB clone were significantly more related to each other than the expression profile of either strain was to that of PAO1. Exposure to H
2
O
2
activated by more than 10-fold the expression of the
cyoABCD
operon, which is key for aerobic respiration, and of oxidative-stress response elements such as the catalase KatB, the alkyl hydroperoxide reductase AhpF, and the thioredoxin reductase 2 operon. Genes for iron and sulfur homeostasis were upregulated. Most enzymes necessary for the conversion of amino acids into the citric acid cycle were globally downregulated at the transcriptional level. Nitrate respiration and arginine fermentation were shut off in the clone TB strains and attenuated in the PAO strain. The transcriptional profiles indicate that the two clone TB strains are more proficient in coping with H
2
O
2
-mediated oxidative stress than the reference strain PAO. According to this data, we recommend study of the transcriptome of strain PAO1 in parallel with those of at least two strains of another clone in order to differentiate common responses from clone- and strain-specific responses and to minimize overinterpretations of microarray data.
Expression of thebmpBGene ofBorrelia burgdorferiIs Modulated by Two Distinct Transcription Termination Events
Authors: Ramamoorthy Ramesh , McClain Natalie A. , Gautam Aarti , Scholl-Meeker Dorothy
Published: April 2005

bmpgene family 36 ofBorrelia burgdorferi, the agent of Lyme disease, comprises four paralogs:bmpA,bmpB,bmpC, andbmpD. ThebmpAandbmpBgenes constitute an operon. All four genes have been found to be transcribed in cultured spirochetes. Expression from thebmpABoperon results in three distinct transcripts of 1.1, 1.6, and 2.4 kb, and the relative expression ofbmpAmRNA is three- to fourfold greater than that ofbmpBmRNA. However, thus far only expression of the BmpA protein has been demonstrated. Therefore, in this study we characterized the origins of the three transcripts and compared the relative expression of the BmpA and BmpB proteins. Northern blotting revealed that the three distinct transcripts originated from a single promoter located upstream ofbmpAbut terminated either 3′ to thebmpA(1.1-kb RNA) orbmpB(2.4-kb RNA) gene or, most unusually, within thebmpBgene (1.6-kb RNA). Termination within thebmpBgene was associated with a functional Rho-independent transcription terminator. At the protein level, we also observed a 4.3-fold greater abundance of BmpA compared to that of BmpB. These studies identify a transcription termination mechanism inB. burgdorferiresulting in the disparate expression of the two genes of thebmpABoperon.
The Metalloprotease ofListeria monocytogenesControls Cell Wall Translocation of the Broad-Range Phospholipase C
Authors: Yeung P. S. Marie , Zagorski Nicholas , Marquis Hélène
Published: April 2005

Listeria monocytogenesis a gram-positive bacterial pathogen that multiplies in the cytosol of host cells and spreads directly from cell to cell. During cell-to-cell spread, bacteria become temporarily confined to secondary vacuoles. The broad-range phospholipase C (PC-PLC) ofL. monocytogenescontributes to bacterial escape from secondary vacuoles. PC-PLC requires cleavage of an N-terminal propeptide for activation, and Mpl, a metalloprotease ofListeria, is involved in the proteolytic activation of PC-PLC. Previously, we showed that cell wall translocation of PC-PLC is inefficient, resulting in accumulation of PC-PLC at the membrane-cell wall interface. In infected cells, rapid cell wall translocation of PC-PLC is triggered by a decrease in pH and correlates with cleavage of the propeptide in an Mpl-dependent manner. To address the role of the propeptide and of Mpl in cell wall translocation of PC-PLC, we generated a cleavage site mutant and a propeptide deletion mutant. The intracellular behavior of these mutants was assessed in pulse-chase experiments. We observed efficient translocation of the proform of the PC-PLC cleavage site mutant in a manner that was pH sensitive and Mpl dependent. However, the propeptide deletion mutant was efficiently translocated into host cells independent of Mpl and pH. Overall, these results suggest that Mpl regulates PC-PLC translocation across the bacterial cell wall in a manner that is dependent on the presence of the propeptide but independent of propeptide cleavage. In addition, similarly to Mpl-mediated cleavage of PC-PLC propeptide, Mpl-mediated translocation of PC-PLC across the bacterial cell wall is pH sensitive.
Identification of Cyclic AMP-Regulated Genes in
Mycobacterium tuberculosis
Complex Bacteria under Low-Oxygen Conditions
Authors: Gazdik Michaela A. , McDonough Kathleen A.
Published: April 2005

Mycobacterium tuberculosis
is the etiological agent of tuberculosis (TB), which kills approximately 2 million people a year despite current treatment options. A greater understanding of the biology of this bacterium is needed to better combat TB disease. The
M. tuberculosis
genome encodes as many as 15 adenylate cyclases, suggesting that cyclic AMP (cAMP) has an important, yet overlooked, role in mycobacteria. This study examined the effect of exogenous cAMP on protein expression in
Mycobacterium bovis
BCG grown under hypoxic versus ambient conditions. Both shaking and shallow standing cultures were examined for each atmospheric condition. Different cAMP-dependent changes in protein expression were observed in each condition by two-dimensional gel electrophoresis. Shaking low-oxygen cultures produced the most changes (12), while standing ambient conditions showed the fewest (2). Five upregulated proteins, Rv1265, Rv2971, GroEL2, PE_PGRS6a, and malate dehydrogenase, were identified from BCG by mass spectrometry and were shown to also be regulated by cAMP at the mRNA level in both
M. tuberculosis
H37Rv and BCG. To our knowledge, these data provide the first direct evidence for cAMP-mediated gene regulation in TB complex mycobacteria.
Completion of the Genome Sequence of
Brucella abortus
and Comparison to the Highly Similar Genomes of
Brucella melitensis
and
Brucella suis
Authors: Halling Shirley M. , Peterson-Burch Brooke D. , Bricker Betsy J. , Zuerner Richard L. , Qing Zhang , Li Ling-Ling , Kapur Vivek , Alt David P. , Olsen Steven C.
Published: April 2005

Brucellosis
is a worldwide disease of humans and livestock that is caused by a
number of very closely related classical
Brucella
species in
the alpha-2 subdivision of the Proteobacteria. We report the complete
genome sequence of
Brucella abortus
field isolate 9-941 and
compare it to those of
Brucella suis
1330 and
Brucella
melitensis
16 M. The genomes of these
Brucella
species
are strikingly similar, with nearly identical genetic content and gene
organization. However, a number of insertion-deletion events and
several polymorphic regions encoding putative outer membrane proteins
were identified among the genomes. Several fragments previously
identified as unique to either
B. suis
or
B.
melitensis
were present in the
B. abortus
genome. Even
though several fragments were shared between only
B. abortus
and
B. suis
,
B. abortus
shared more fragments and had
fewer nucleotide polymorphisms with
B. melitensis
than
B.
suis
. The complete genomic sequence of
B. abortus
provides an important resource for further investigations into
determinants of the pathogenicity and virulence phenotypes of these
bacteria.
Surprising Dependence on Postsegregational Killing of Host Cells for Maintenance of the Large Virulence Plasmid of
Shigella flexneri
Authors: Sayeed Sameera , Brendler Therese , Davis Michael , Reaves Lucretia , Austin Stuart
Published: April 2005

Low-copy-number plasmids all encode multiple systems to ensure their propagation, including replication, partition (active segregation), and postsegregational killing (PSK) systems. PSK systems kill those rare cells that lose the plasmid due to replication or segregation errors. PSK systems should not be used as the principle means of maintaining the plasmid. The metabolic cost of killing the many cured cells that would arise from random plasmid segregation is far too high. Here we describe an interesting exception to this rule. Maintenance of the large virulence plasmid of
Shigella flexneri
is highly dependent on one of its PSK systems,
mvp
, at 37°C, the temperature experienced during pathogenesis. At 37°C, the plasmid is very unstable and mvp efficiently kills the resulting cured bacterial cells. This imposes a major growth disadvantage on the virulent bacterial population. The systems that normally ensure accurate plasmid replication and segregation are attenuated or overridden at 37°C. At 30°C, a temperature encountered by
Shigella
in the outside environment, the maintenance systems function normally and the plasmid is no longer dependent on
mvp
. We discuss why the virulent pathogen tolerates this self-destructive method of propagation at the temperature of infection.
Enhanced Synthesis of Internalin A inaroMutants ofListeria monocytogenesIndicates Posttranscriptional Control of theinlABmRNA
Authors: Stritzker Jochen , Schoen Christoph , Goebel Werner
Published: April 2005

Listeria monocytogenesmutants with deletions inaroA,aroB, oraroEexhibited strong posttranscriptional upregulation of internalin A (InlA) and InlB synthesis, which resulted in a more-than-10-fold increase in InlA-mediated internalization by epithelial Caco-2 cells and a 4-fold increase in InlB-mediated internalization by microvascular endothelial cells (human brain microvascular endothelial cells) compared to the wild-type strain. The increase in InlA and InlB production was not due to enhanced PrfA- and/or sigma factor B (SigB)-dependentinlABtranscription but was caused by enhanced translation of theinlABtranscripts in thearomutants. AllinlA(B) transcripts had a 396-nucleotide upstream 5′ untranslated region (UTR). Different deletions introduced into this UTR led to significant reductions in InlA and InlB synthesis; enhanced translation of all of the truncated transcripts in thearomutants was, however, still observed. Thus, translation of theinlABtranscripts was subject to two modes of posttranscriptional control, one mediated by the UTR structure and the other mediated by thearomutation. The latter mode of control seemed to be related to the predominantly anaerobic metabolism of thearomutants.
Characterization of Type 2 Quorum Sensing in
Klebsiella pneumoniae
and Relationship with Biofilm Formation
Authors: Balestrino Damien , Haagensen Janus A. J. , Rich Chantal , Forestier Christiane
Published: April 2005

Quorum sensing is a process by which bacteria communicate by using secreted chemical signaling molecules called autoinducers. Many bacterial species modulate the expression of a wide variety of physiological functions in response to changes in population density by this mechanism. In this study, the opportunistic pathogen
Klebsiella pneumoniae
was observed to secrete type 2 signaling molecules. A homologue of
luxS
, the gene required for AI-2 synthesis in
Vibrio harveyi
, was isolated from the
K. pneumoniae
genome. A
V. harveyi
bioassay showed the
luxS
functionality in
K. pneumoniae
and its ability to complement the
luxS
-negative phenotype of
Escherichia coli
DH5α. Autoinducer activity was detected in the supernatant, and maximum expression of specific messengers detected by quantitative reverse transcription-PCR analysis occurred during the late exponential phase. The highest levels of AI-2 were observed in minimal medium supplemented with glycerol. To determine the potential role of
luxS
in colonization processes, a
K. pneumoniae luxS
isogenic mutant was constructed and tested for its capacity to form biofilms in vitro on an abiotic surface and to colonize the intestinal tract in a murine model. No difference was observed in the level of intestinal colonization between the wild-type strain and the
luxS
mutant. Microscopic analysis of biofilm structures revealed that the
luxS
mutant was able to form a mature biofilm but with reduced capacities in the development of microcolonies, mostly in the early steps of biofilm formation. These data suggest that a LuxS-dependent signal plays a role in the early stages of biofilm formation by
K. pneumoniae
.
Functional Reassembly of the
Escherichia coli
Maltose Transporter following Purification of a MalF-MalG Subassembly
Authors: Sharma Susan , Davis Johnny A. , Ayvaz Tulin , Traxler Beth , Davidson Amy L.
Published: April 2005

Taking advantage of a chaperone-like function of MalK, a stable complex of MalF-MalG could be solubilized from the
Escherichia coli
membrane and purified in high yield in the absence of MalK. This MalF-MalG complex was competent for efficient reassembly of a functional MalFGK
2
maltose transporter complex both in detergent solution and in proteoliposomes.
Identification of
rcnA
(
yohM
), a Nickel and Cobalt Resistance Gene in
Escherichia coli
Authors: Rodrigue Agnès , Effantin Géraldine , Mandrand-Berthelot Marie-Andrée
Published: April 2005

We report here on the isolation and primary characterization of the
yohM
gene of
Escherichia coli
. We show that
yohM
encodes a membrane-bound polypeptide conferring increased nickel and cobalt resistance in
E. coli. yohM
was specifically induced by nickel or cobalt but not by cadmium, zinc, or copper. Mutation of
yohM
increased the accumulation of nickel inside the cell, whereas cells harboring
yohM
in multicopy displayed reduced intracellular nickel content. Our data support the hypothesis that YohM is the first described efflux system for nickel and cobalt in
E. coli
. We propose
rcnA
(resistance to cobalt and nickel) as the new denomination of
yohM
.
Comparison of injury case fatality rates in the United States and New Zealand
Authors: Spicer R , Miller T , Langley J , Stephenson S
Published: April 2005

Objective:To compare injury case fatality rates in the United States (US) with New Zealand (NZ) to guide future information collection, research, and evaluation.

Design:Using NZ (1992–96) and US (1996–98) mortality censuses, NZ national 1992–96 hospital discharge censuses, and US 1996–98 National Hospital Discharge Survey data, the authors compared case fatality rates by mechanism and intent of injury and age group. The analysis was restricted to severe injuries (AIS⩾3).

Subjects:NZ (1992–96) and US (1996–98) populations.

Main outcome measures:Ratio of case fatality rates in NZ versus the US (RCFR(NZ:US)).

Results:Overall, among cases meeting the study criteria, unintentional injuries were 1.57 times more likely fatal in NZ and intentional assault injuries were 1.14 times more likely to be fatal in the US. Firearms were involved in 50% of US assaults versus 8% of NZ assaults. By mechanism, cutting/piercing injuries were 1.86, firearm injuries were 1.41, and motor vehicle injuries were 1.44 times more to be likely fatal in NZ. Natural/environmental injuries (RCFRNZ:US = 0.57), unintentional poisonings (RCFRNZ:US = 0.26), and unintentional suffocations (RCFRNZ:US = 0.67) were significantly more likely to be fatal in the US.

Conclusions:Possible reasons for the observed results include: differences in geography and proportion of population in rural areas, trauma system differences, road design and vehicle types, seat belt use, larger role of firearms in US assaults, coding practices, policies, and environmental factors. Disparities evoke hypotheses to test in future research that will guide priority setting and intervention.
Gender differences for non-fatal unintentional fall related injuries among older adults
Authors: Stevens J A , Sogolow E D
Published: April 2005

Objectives:To quantify gender differences for non-fatal unintentional fall related injuries among US adults age 65 years and older treated in hospital emergency departments (EDs).

Methods:The authors analyzed data from a nationally representative sample of ED visits for January 2001 through December 2001, available through the National Electronic Injury Surveillance System All Injury Program (NEISS-AIP). For each initial ED visit, coders record one principal diagnosis (usually the most severe) and one primary part of the body affected.

Results:Based on 22 560 cases, an estimated 1.64 million older adults were treated in EDs for unintentional fall injuries. Of these, approximately 1.16 million, or 70.5%, were women. Fractures, contusions/abrasions, and lacerations accounted for more than three quarters of all injuries. Rates for injury diagnoses were generally higher among women, most notably for fractures which were 2.2 times higher than for men. For all parts of the body, women’s injury rates exceeded those of men. Rate ratios were greatest for injuries of the leg/foot (2.3), arm/hand (2.0), and lower trunk (2.0). The hospitalization rate for women was 1.8 times that for men.

Conclusions:Among older adults, non-fatal fall related injuries disproportionately affected women. Much is known about effective fall prevention strategies. We need to refine, promote, and implement these interventions. Additional research is needed to tailor interventions for different populations and to determine gender differences in the underlying causes and/or circumstances of falls. This information is vital for developing and implementing targeted fall prevention strategies.
Winning, losing, and violence
Authors: Sivarajasingam V , Moore S , Shepherd J P
Published: April 2005

Background:Although international sports events attract huge interest, and results can be a barometer of popular national standing, their impact on violent behaviour has not been investigated.

Methods:Associations between assault related emergency department (ED) attendances and international sporting events (home and away rugby and soccer matches) in a European capital city (Cardiff) served by one ED, between 1 May 1995 and 30 April 2002 were investigated. The frequency of assault related ED attendances were studied relative to whether the national team won or lost, controlling for potential covariates: match attendance, match location (home/away), results (win/lose), net scores, and day of match (weekend/weekday). Multiple linear regression was used to identify significant associations with ED assault related attendances.

Results:Matches which the Wales team won (p = 0.03), match attendance (p<0.001), and weekend matches (p<0.001) were positively associated with ED assault related injury attendances. Assault frequency measured in this way was no different for home and away matches.

Conclusions:Assault injury resulting in ED treatment was more frequent when national teams won than when they lost. Sport type made no difference. Violence prevention efforts should be increased on international match days, when the national team is expected to win, when match attendance is large, and for away as well as home matches.
INTERVENING DUALITY STRATEGIC EQUIVALENCE AND NONCONSTANT SUM BIMATRIX GAMES
Authors: RYAN MICHAEL J.
Published: April 2005

In 1995 I introduced the idea of intervening duality with the context of matching pennies games between two persons. I subsequently extended that idea with papers relating first to experimenter-experiment interactions via an intervening — and explicitly specified — die casting experiment and, secondly, to farmer-landowner rent bargaining with intervening weather forecasts modelled as bargaining instruments. The purpose of the present paper is to provide general results which not only specialise to these three previous classes of applications, but which use the idea of strategic equivalence to provide a formal basis for the analysis of large classes of explicitly nonconstant sum bimatrix games, including the prisoners dilemma.
A NOTE ON REPEATED GAMES WITH VANISHING ACTIONS
Authors: JOOSTEN REINOUD
Published: April 2005

A two-person general-sum repeated game with vanishing actions is an infinitely repeated game where the players face the following restrictions. Each action must be used by player k ∈ {1,2} at least once in every rk ∈ ℕ consecutive stages, otherwise the action vanishes for the remaining play. We assume that the players wish to maximize their limiting average rewards over the entire time-horizon.

A strategy-pair is jointly convergent if for each action pair a number exists to which the relative frequency with which this action pair is chosen, converges with probability one. A pair of feasible rewards is called individually rational if each player receives at least the threat-point reward, i.e., the amount which he can guarantee himself regardless of what the opponent does given r1, r2 and the actions available in the long run. In a repeated game with vanishing actions, there may exist multiple threat points which are endogenous to the play.

We prove that all individually-rational jointly-convergent pure-strategy rewards can be supported by an equilibrium. Furthermore, each convex combination of individually-rational jointly-convergent pure-strategy rewards, can be supported by an equilibrium for m × n-games provided r1 > m ≥ 2, r2 > n ≥ 2.
COMPARISON OF DEDUCTION THEOREMS IN DIVERSE LOGIC SYSTEMS
Authors: WANG GUO-JUN
Published: April 2005

Deduction theorem and its weak forms in classical mathematical logic system, Łukasiewicz logic system, Gödel logic system, product logic system, and the fuzzy logic system ℒ* are discussed and compared. It is pointed out that the weak form of deduction theorem in ℒ* has a clear structure and can be employed to define the concept of consistency degrees of finite theories. Moreover, it is clarified that the negation operator of Gödel type is too strong and is therefore unsuitable for establishing fuzzy logic systems.
Influence of insulin and free fatty acids on contractile function in patients with chronically stunned and hibernating myocardium
Authors: Wiggers Henrik , Nørrelund Helene , Nielsen Søren Steen , Andersen Niels H. , Nielsen-Kudsk Jens Erik , Christiansen Jens S. , Nielsen Torsten T. , Møller Niels , Bøtker Hans Erik
Published: April 2005

It is unknown whether short-term modulation of substrate supply affects cardiac performance in heart failure patients with chronic ischemic myocardium. The aim of this study was to determine whether modulation of myocardial substrate metabolism with insulin and free fatty acids (FFAs) affects contractile function of chronically stunned (CST) and hibernating (HIB) myocardium at rest and after maximal exercise. We studied eight nondiabetic patients with ejection fraction (EF) 30 ± 4% (SE) and CST/HIB in 49 ± 6% of the left ventricle: 36 ± 6% CST and 13 ± 2% HIB as determined by 99mTechnetium-Sestamibi single photon emission computed tomography (SPECT) and [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET). Each patient was subjected to a 3-h infusion of 1) saline, 2) insulin-glucose (i.e., euglycemic insulin clamp; high insulin, suppressed FFA), and 3) somatostatin-heparin (suppressed insulin, high FFA). Echocardiographic endpoints were global EF and regional contractile function [maximum velocity ( Vmax) and strain rate (εmax)] as determined by tissue Doppler imaging at steady state and after maximal exercise. EF was similar at baseline and steady state and increased after exercise to 36 ± 5% ( P < 0.05). Baseline regional Vmax and εmax were highest in control, intermediate in CST and HIB, and lowest in infarct regions ( P < 0.05). Steady-state EF, Vmax, and εmax were not affected by metabolic modulation in any region. After maximal exercise, contractile function increased in control, CST, and HIB ( P < 0.05), but not in infarct, regions. Exercise-induced contractile increments were unaffected by metabolic modulation. Metabolic modulation does not influence contractile function in CST and HIB regions. Chronic ischemic myocardium has preserved ability to adapt to extreme, short-term changes in substrate supply at rest and after maximal exercise.
Enhanced matrix metalloproteinase activity in skeletal muscles of rats with congestive heart failure
Authors: Schiøtz Thorud Hanne M. , Stranda Annicke , Birkeland Jon-Arne , Lunde Per K. , Sjaastad Ivar , Kolset Svein O. , Sejersted Ole M. , Iversen Per O.
Published: April 2005

Patients with congestive heart failure (CHF) are prone to increased skeletal muscle fatigue. Elevated circulatory concentrations of tumor necrosis factor (TNF)-α and monocyte chemoattractant protein-1, which may stimulate matrix metalloproteinase (MMP) activity and, thereby, contribute to skeletal muscle dysfunction, are frequently found in CHF. However, whether skeletal muscle MMP activity is altered in CHF is unknown. Hence, we have used a gelatinase assay to assess the activity of MMP and tissue inhibitors of MMP in single skeletal muscles of rats with CHF 6 wk after induction of myocardial infarction. Sham-operated (Sham) rats were used as controls. We also measured the gene expression and protein contents of MMP-2 and MMP-9 in skeletal muscles of these rats. Plasma MMP activity was nearly seven times higher ( P < 0.05) in CHF than in Sham rats. Concomitantly, the MMP activity within single slow- and fast-twitch skeletal muscles of CHF rats increased two- to fourfold compared with Sham animals, whereas tissue inhibitor of MMP activity did not differ ( P > 0.05). Preformed MMP-2 and MMP-9 were probably activated in CHF, because neither their gene expression nor protein levels were altered ( P > 0.05). Serum concentrations of TNF-α and monocyte chemoattractant protein-1 remained unchanged ( P > 0.05) between CHF and Sham rats during the 6-wk observation period. We conclude that development of CHF in rats enhances MMP activity, which in turn may distort the normal contractile function of skeletal muscle, thereby contributing to increased skeletal muscle fatigue.
Ancestry explains the blunted ventilatory response to sustained hypoxia and lower exercise ventilation of Quechua altitude natives
Authors: Brutsaert Tom D. , Parra Esteban J. , Shriver Mark D. , Gamboa Alfredo , Rivera-Ch Maria , León-Velarde Fabiola
Published: April 2005

Andean high-altitude (HA) natives have a low (blunted) hypoxic ventilatory response (HVR), lower effective alveolar ventilation, and lower ventilation (VE) at rest and during exercise compared with acclimatized newcomers to HA. Despite blunted chemosensitivity and hypoventilation, Andeans maintain comparable arterial O2saturation (SaO2). This study was designed to evaluate the influence of ancestry on these trait differences. At sea level, we measured the HVR in both acute (HVR-A) and sustained (HVR-S) hypoxia in a sample of 32 male Peruvians of mainly Quechua and Spanish origins who were born and raised at sea level. We also measured resting and exercise VE after 10–12 h of exposure to altitude at 4,338 m. Native American ancestry proportion (NAAP) was assessed for each individual using a panel of 80 ancestry-informative molecular markers (AIMs). NAAP was inversely related to HVR-S after 10 min of isocapnic hypoxia ( r = −0.36, P = 0.04) but was not associated with HVR-A. In addition, NAAP was inversely related to exercise VE ( r = −0.50, P = 0.005) and ventilatory equivalent (VE/V̇o2, r = −0.51, P = 0.004) measured at 4,338 m. Thus Quechua ancestry may partly explain the well-known blunted HVR ( 10 , 35 , 36 , 57 , 62 ) at least to sustained hypoxia, and the relative exercise hypoventilation at altitude of Andeans compared with European controls. Lower HVR-S and exercise VE could reflect improved gas exchange and/or attenuated chemoreflex sensitivity with increasing NAAP. On the basis of these ancestry associations and on the fact that developmental effects were completely controlled by study design, we suggest both a genetic basis and an evolutionary origin for these traits in Quechua.
Alteration in Gene Expression Profile by Full-Length Hepatitis B Virus Genome
Authors: Nakanishi Fumihiko , Ohkawa Kazuyoshi , Ishida Hisashi , Hosui Atsushi , Sato Aki , Hiramatsu Naoki , Ueda Keiji , Takehara Tetsuo , Kasahara Akinori , Sasaki Yutaka , Hori Masatsugu , Hayashi Norio
Published: April 2005

Persistent expression of hepatitis B virus (HBV) proteins is thought to be involved in virus-related hepatocarcinogenesis. Here, we compared the gene expression profile of cells persistently expressing the full-length HBV with that of negative control cells to comprehensively investigate virus-mediated changes in the gene expression of the host cells. RNA samples from both virus-expressing and negative control cells were used for the DNA array assay. DNA array assay and subsequent corroboration assays revealed that expression of 14 of 1,176 genes (1.2%) was altered in response to virus expression. The upregulated genes included CD44, high mobility group protein-I, thymosin beta-10 and 27-kD heat shock protein, while the downregulated genes included NM23-H1, all of which are thought to be associated with the development or progression of carcinoma in the liver or other organs. Furthermore, virus expression resulted in the decrease of two apoptosis-inducing molecules, caspase-3 and BAX, which may also contribute to carcinogenesis through prolonged survival of the host cell. Thus, expression of the virus genome caused carcinogenesis-related changes in host cell gene expression. HBV expression may change the host cell to a malignant phenotype through alterations in the expression levels of a set of genes.