bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence of
bar
Minigene Expression and tRNA
2
Ile
Sequestration as Peptidyl-tRNA
2
Ile
during Lambda Bacteriophage Development
Authors: Oviedo de Anda Norma Angélica , Kameyama Luis , Galindo José Manuel , Guarneros Gabriel , Hernandez-Sanchez Javier 
Published: August 2004

ABSTRACT

Lambda bacteriophage development is impaired in
Escherichia coli
cells defective for peptidyl (pep)-tRNA hydrolase (Pth). Single-base-pair mutations (
bar
−
) that affect translatable two-codon open reading frames named
bar
minigenes (
bar
I or
bar
II) in the lambda phage genome promote the development of this phage in Pth-defective cells (rap cells). When the
bar
I minigene is cloned and overexpressed from a plasmid, it inhibits protein synthesis and cell growth in rap cells by sequestering

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as

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. Either

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or Pth may reverse these effects. In this paper we present evidence that both
bar
I and
bar
II minigenes are translatable elements that sequester

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as

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. In addition, overexpression of the
bar
I minigene impairs the development even of
bar
−
phages in rap cells. Interestingly, tRNA or Pth may reestablish lambda phage development. These results suggest that lambda
bar
minigenes are expressed and

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is sequestered as

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during lambda phage development.
Polymorphic Mutation Frequencies in
Escherichia coli
: Emergence of Weak Mutators in Clinical Isolates
Authors: Baquero María-Rosario , Nilsson Annika I. , del Carmen Turrientes María , Sandvang Dorthe , Galán Juan Carlos , Martínez Jose Luís , Frimodt-Møller Niels , Baquero Fernando , Andersson Dan I. 
Published: August 2004

ABSTRACT

Polymorphisms in the rifampin resistance mutation frequency (
f
) were studied in 696
Escherichia coli
strains from Spain, Sweden, and Denmark. Of the 696 strains, 23% were weakly hypermutable (4 × 10
−8
≤
f
< 4 × 10
−7
), and 0.7% were strongly hypermutable (
f
≥ 4 × 10
−7
). Weak mutators were apparently more frequent in southern Europe and in blood isolates (38%) than in urinary tract isolates (25%) and feces of healthy volunteers (11%).
The RpoS Sigma Factor in the Dissimilatory Fe(III)-Reducing Bacterium
Geobacter sulfurreducens
Authors: Núñez Cinthia , Adams Lorrie , Childers Susan , Lovley Derek R. 
Published: August 2004

ABSTRACT

Geobacter sulfurreducens
RpoS sigma factor was shown to contribute to survival in stationary phase and upon oxygen exposure. Furthermore, a mutation in
rpoS
decreased the rate of reduction of insoluble Fe(III) but not of soluble forms of iron. This study suggests that RpoS plays a role in regulating metabolism of
Geobacter
under suboptimal conditions in subsurface environments.
Erwinia chrysanthemiO Antigen Is Required for Betaine Osmoprotection in High-Salt Media
Authors: Touzé Thierry , Goude Renan , Georgeault Sylvie , Blanco Carlos , Bonnassie Sylvie 
Published: August 2004

ABSTRACTCellular components necessary for osmoprotection are poorly known. In this study we show that O antigen is specifically required for the effectiveness of betaines as osmoprotectants forErwinia chrysanthemiin saline media. The phenotype is correlated with the inability ofrfbmutant strains to maintain a high accumulation level of betaines in hypersaline media.
Excision of the
Shigella
Resistance Locus Pathogenicity Island in
Shigella flexneri
Is Stimulated by a Member of a New Subgroup of Recombination Directionality Factors
Authors: Luck Shelley N. , Turner Sally A. , Rajakumar Kumar , Adler Ben , Sakellaris Harry 
Published: August 2004

ABSTRACT

Pathogenicity islands are capable of excision and insertion within bacterial chromosomes. We describe a protein, Rox, that stimulates excision of the
Shigella
resistance locus pathogenicity island in
Shigella flexneri
. Sequence analysis suggests that Rox belongs to a new subfamily of recombination directionality factors, which includes proteins from P4, enterohemorrhagic
Escherichia coli
, and
Yersinia pestis
.
Gaps, conflicts, and consensus in the ethics statements of professional associations, medical groups, and health plans
Authors: Berkman N D , Wynia M K , Churchill L R 
Published: August 2004

Background:Patients today interact with physicians, physician groups, and health plans, each of which may follow distinct ethical guidelines.Method:We systematically compared physician codes of ethics with ethics policies at physician group practices and health plans, using the 1998–99 policies of 38 organisations—18 medical associations (associations), nine physician group practices (groups), and 12 health plans (plans)—selected using random and stratified purposive sampling. A clinician and a social scientist independently abstracted each document, using a 397-item health care ethics taxonomy; a reconciled abstraction form was used for analysis. This study focuses on ethics policies regarding professional obligation towards patients, resource allocation, and care for the vulnerable in society.Results:A majority in all three groups mention “fiduciary obligations” of one sort or another, but associations generally address physician/patient relations but not health plan obligations, while plans rarely endorse physicians’ obligations of advocacy, beneficence, and non-maleficence. Except for occasional mentions of cost effectiveness or efficiency, ethical considerations in resource allocation rarely arise in the ethics policies of all three organisational types. Very few associations, groups, or plans specifically endorse obligations to vulnerable populations.Conclusions:With some important exceptions, we found that the ethics policies of associations, groups, and plans are narrowly focused and often ignore important ethical concerns for society, such as resource allocation and care for vulnerable populations. More collaborative work is needed to build integrated sets of ethical standards that address the aims and responsibilities of the major stakeholders in health care delivery.
The patient who refuses nursing care
Authors: Aveyard H 
Published: August 2004

Objectives:The aim of this paper is to examine the way in which nurses manage patients who refuse nursing care procedures.Design:This paper reports on a qualitative study which was undertaken to explore the way in which nurses obtain consent prior to nursing care procedures. Focus groups were carried out to obtain background data concerning how consent is obtained. Critical incidents were collected through in depth interviews as a means of focusing on specific incidents in clinical practice.Setting:Two teaching hospitals in England.Participants:Purposive sample of qualified nurses.Results:When a patient refuses nursing care, nurses respond by giving information until the patient finally accedes to the procedure. Nurses will go to great lengths to achieve patients’ agreement to the procedure, but the extent to which the agreement remains voluntary cannot be ascertained by the data collected in this study. If the patient does not eventually agree to a procedure, there is evidence that nurses will administer the care in the absence of consent.Conclusions:Nurses are concerned to obtain the patient’s consent prior to the administration of nursing care but if this cannot be achieved do not regard obtaining consent as an absolute requirement. Consent is preferred, but not considered essential. Nurses have some understanding of the principles of informed consent but do not apply them to everyday clinical nursing practice.
End of life decisions: attitudes of Finnish physicians
Authors: Hildén H-M , Louhiala P , Palo J 
Published: August 2004

Objectives:This study investigated Finnish physicians’ experiences of decisions concerning living wills and do not resuscitate (DNR) orders and also their views on the role of patients and family members in these decisions.Design:A questionnaire was sent to 800 physicians representing the following specialties: general practice (n = 400); internal medicine (n = 207); neurology (n = 100), and oncology (n = 93).Results:The response rate was 56%. Most of the respondents had a positive attitude toward (92%), and respect for (86%) living wills, and 72% reported situations in which such a will would have been helpful, although experience with their use was limited. The physicians reported both benefits and problems with living wills. Thirteen per cent had completed a living will of their own. Half did not consider living wills to be reliable if they were several years old. Do not resuscitate orders were interpreted in two ways: resuscitation forbidden (70%) or only palliative (symptom oriented) care required (30%). The respondents also documented DNR orders differently. Seventy two per cent discussed DNR decisions always or often with patients able to communicate, and even 76% discussed DNR orders with the family members of patients unable to communicate. Most respondents were able to approach a dying patient without difficulty. They also felt that education in general was needed.Conclusions:In general Finnish physicians accept living wills, but find they are accompanied by several problems. Many problems could be avoided if physicians and patients conducted progressive discussions about living wills. The differing interpretations of DNR orders are a matter of concern in that they may affect patient treatment. The promotion of patient autonomy with respect to treatment seems rather good, but the limitations of the study need to be kept in mind.
Students’ attitudes and potential behaviour to a competent patient’s request for withdrawal of treatment as they pass through a modern medical curriculum
Authors: Goldie J , Schwartz L , Morrison J 
Published: August 2004

Objective:To examine students’ attitudes and potential behaviour to a competent patient’s request for withdrawal of treatment as they pass through a modern medical curriculum.Design:Cohort design.Setting:University of Glasgow Medical School, United Kingdom.Subjects:A cohort of students entering Glasgow University’s new learner centred, integrated medical curriculum in October 1996.Methods:Students’ responses before and after year 1, after year 3, and after year 5 to the assisted suicide vignette of the Ethics in Health Care Survey instrument, were examined quantitatively and qualitatively. Analysis of students’ multichoice answers enabled measurement of the movement towards professional consensus opinion. Analysis of written justifications helped determine whether their reasoning was consistent with professional consensus and enabled measurement of change in knowledge content and recognition of the values inherent in the vignette. Themes on students’ reasoning behind their decision to withdraw treatment or not were also identified.Results:Students’ answers were found to be consistent with professional consensus opinion precurriculum and remained so throughout the curriculum. There was an improvement in the knowledge content of the written responses following the first year of the curriculum, which was sustained postcurriculum. However, students were found to analyse the section mainly in terms of autonomy, with few responses considering the other main ethical principles or the wider ethical perspective. Students were unclear on their legal responsibilities.Conclusions:Students should be encouraged to consider all relevant ethical principles and the wider ethical perspective when deliberating ethical dilemmas. Students should have a clear understanding of their legal responsibilities.
Stem cells, embryos, and the environment: a context for both science and ethics
Authors: Towns C R , Jones D G 
Published: August 2004

Debate on the potential and uses of human stem cells tends to be conducted by two constituencies—ethicists and scientists. On many occasions there is little communication between the two, with the result that ethical debate is not informed as well as it might be by scientific insights. The aim of this paper is to highlight those scientific insights that may be of relevance for ethical debate.Environmental factors play a significant role in identifying stem cells and their various subtypes. Research related to the role of the microenvironment has led to emphasis upon “plasticity”, which denotes the ability of one type of stem cell to undergo a transition to cells from other lineages. This could increase the value given to adult stem cells, in comparison with embryonic stem cell research. Any such conclusion should be treated with caution, however, since optimism of this order is not borne out by current research.The role of the environment is also important in distinguishing between the terms totipotency and pluripotency. We argue that blastocysts (early embryos) and embryonic stem cells are only totipotent if they can develop within an appropriate environment. In the absence of this, they are merely pluripotent. Hence, blastocysts in the laboratory are potentially totipotent, in contrast to their counterparts within the human body which are actually totipotent. This may have implications for ethical debate, suggesting as it does that arguments based on potential for life may be of limited relevance.
Woman wants dead fiancé’s baby: who owns a dead man’s sperm
Authors: Spriggs M 
Published: August 2004

The Brisbane Supreme Court has denied an Australian woman’s request to harvest and freeze her dead fiancé’s sperm for future impregnation. After she was denied access to the sperm, the woman learnt that her fiancé may have been a sperm donor and she began checking to find out if his sperm was still available. Given what we know, there is a good ethical argument that the woman should have access to the sperm and should be allowed to have her dead fiancé’s child.Another aspect of this case is that it illustrates the way in which ethics, law, and personal opinion can differ.
Statin and fibrate treatment of combined hyperlipidemia: the effects on some novel risk factors
Authors: Keber Irena , Žegura Branka , Simčič Saša , Božič Mojca , Fressart Martine , Stegnar Mojca , Šebeštjen Miran 
Published: August 2004

SummaryThe effects of cerivastatin and fenofibrate on proteins involved in haemostasis and on markers of inflammation were investigated in otherwise healthy middle-aged males with combined hyperlipidemia. Besides classical risk factors, other so-called novel risk factors for coronary artery disease are seen to be playing an increasingly important role in the development and progression of atherosclerosis. Thirty-eight males, aged 49 ± 5 years were randomised to 12 weeks treatment either with cerivastatin at a daily dose of 0.2 mg to 0.4 mg to achieve the LDL cholesterol goal of <3.0 mM, or with fenofibrate 250 mg daily. Fasting serum lipids, homocysteine, total and free tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor (PAI-1) and tissue plasminogen activator (t-PA) antigen and activity, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured. No change in homocysteine level was observed in the cerivastatin group, while after fenofibrate administration it increased (p <0.0001).Total TFPI decreased significantly after cerivastatin (p = 0.002), but not after fenofibrate. Free TFPI did not decrease after either drug. Neither drug affected (t-PA) antigen and activity, while fenofibrate increased PAI-1 antigen (p <0.05) and activity (p <0.05). Cerivastatin decreased serum CRP values by 49.5% (p = 0.001), and fenofibrate by 29.8% (p = 0.03). The decreases of CRP in the two groups differed significantly (p = 0.04). IL-6 levels decreased significantly in the fenofibrate group (39%; p <0.0001), but not in the cerivastatin group (15%; p = 0.24) No significant decreases were observed for TNF-α. Cerivastatin had neutral effects on fibrinolysis, homocysteine or coagulation. On the other hand, fenofibrate increased PAI-1 antigen and activity and homocysteine, and did not affect coagulation. Both cerivastatin and fenofibrate reduced CRP levels, the decrease being significantly greater after cerivastatin. Fenofibrate also significantly decreased IL-6.
Inhibition of endothelial cell tube formation by the low molecular weight heparin, tinzaparin, is mediated by tissue factor pathway inhibitor
Authors: Mohamed S. , Mousa Shaker 
Published: August 2004

SummaryHeparin and low molecular weight heparins (LMWHs) have both antithrombotic and anti-angiogenic activities. The antiangiogenic activity of LMWH may be associated with the release of endothelial tissue factor pathway inhibitor (TFPI), an important endogenous inhibitor of tissue factor/Factor VIIa (TF/fVIIa).To evaluate the effects of LMWH, tinzaparin, and TFPI in a model of angiogenesis-mediated processes, we compared the effects of tinzaparin, and recombinant TFPI in inhibiting either basic fibroblast growth factor-2 (FGF2) or TF/fVIIainduced endothelial cell tube formation in human umbilical vein endothelial cells (HUVEC).Our results show that tinzaparin and recombinant TFPI both blocked endothelial tube formation induced by either FGF2 or TF/fVIIa, in a concentration-dependent manner. Endothelial tube formation was only marginally inhibited by a potent and specific anti-Factor Xa, recombinant tick anticoagulant protein (rTAP). A monoclonal anti-TFPI antibody reversed the inhibitory effects of either tinzaparin or recombinant-TFPI on HUVEC tube formation. Tinzaparin fractions in the range of 8,000 to 12,600 Da were most effective in stimulating the release of TFPI from HUVEC. These results suggest that the inhibitory effect of the LMWH tinzaparin on endothelial tube formation is associated with stimulation of the release of TFPI, but not to anti-Factor Xa activity.
Mice deficient in tissue factor demonstrate attenuated intimal hyperplasia in response to vascular injury and decreased smooth muscle cell migration
Authors: Pyo Robert , Sato Yuichiro , Mackman Nigel , Taubman Mark 
Published: August 2004

SummaryTissue factor (TF) is the primary initiator of the coagulation cascade and is thought to play a key role in the generation of arterial thrombosis. Recent studies have suggested that TF mediates inflammatory processes in the arterial wall and may be an important regulator of intimal hyperplasia. We have employed genetically engineered mice (mTF−/−/hTF+) with markedly diminished TF activity (≈1% normal levels) to examine the role of TF in mediating the response to arterial injury. mTF−/−/hTF+ displayed a marked reduction in intimal hyperplasia (46% decrease in intimal area, 60% decrease in intimal/medial ratio) in response to femoral artery injury when compared to wild type controls. The decreased intimal hyperplasia seen in low TF mice was noted in a model of vascular injury not associated with significant thrombosis, suggesting that it may be mediated by non-procoagulant properties of TF. Smooth muscle cells from mTF−/−/hTF+ mice grew normally in response to serum, but exhibited a marked defect in cell migration in a modified Boyden chamber assay. In contrast, there was no difference in platelet derived growth factorinduced migration, suggesting that the effect of TF on smooth muscle cell migration is agonist dependent. These data suggest that TF may mediate intimal hyperplasia by regulating smooth muscle cell migration.
Compartment- and cell-specific expression of coagulation and fibrinolysis factors in the murine lung undergoing inhalational versus intravenous endotoxin application
Authors: Wygrecka Malgorzata , Markart Philipp , Ruppert Clemens , Kuchenbuch Tim , Fink Ludger , Bohle Rainer , Grimminger Friedrich , Seeger Werner , Günther Andreas 
Published: August 2004

SummaryIntraalveolar and intravascular fibrin formation are typical hallmarks of acute inflammatory lung diseases, and may foster subsequent fibroproliferative events.We investigated the regulation and cellular sources of key coagulation and fibrinolysis factors in lungs undergoing compartmentalized challenge with endotoxin (LPS). BALB/c mice received 15ng LPS either by intravenous injection or by inhalation. Quantitative gene expression analysis (real-time RT-PCR) was performed for tissue factor (TF),TF pathway inhibitor (TFPI), tissue-type plasminogen activator (t-PA), urokinase-type-PA (u-PA), PA inhibitor-1 (PAI-1), and PAI-2 in peripheral white blood cells (PBC) as well as in alveolar macrophages (AM), type-II pneumocytes (ATII), endothelial cells (EC) and smooth muscle cells (SMC), all obtained by laser microdissection. Neither route of LPS administration caused substantial protein leakage or leukocyte recruitment into the alveolar space. Compartmentalized upregulation of procoagulant and downregulation of fibrinolytic activities was, however, observed in response to both modes of LPS challenge. Intraalveolar endotoxin, in particular, caused strong upregulation of TF (∼ 20-fold increase in gene expression) and PAI-2 (225-fold increase) in microdissected AM, upregulation of PAI-1 in microdissected ATII (300-fold increase) and EC (180-fold increase), upregulation of t-PA in EC (40-fold), and downregulation of u-PA in vascular smooth muscle cells. TFPI was largely unchanged in all cell types, and PBC showed no major gene regulatory response to inhaled endotoxin. We conclude that the lung possesses a cell-specific alveolar coagulation and fibrinolysis system, being independent of the vascular coagulation cascade and responding readily with enhanced procoagulant and anti-fibrinolytic activities to LPS challenge.