bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetics and Regulation of the Major Enzymes of Alanine Synthesis inEscherichia coli
Authors: Kim Sok Ho , Schneider Barbara L. , Reitzer Larry 
Published: August 2010

ABSTRACTGenetic analysis of alanine synthesis in the model genetic organismEscherichia colihas implicatedavtA, the still uncharacterizedalaAandalaBgenes, and probably other genes. We identifiedalaAasyfbQ. We then transferred mutations in several transaminase genes into ayfbQmutant and isolated a mutant that required alanine for optimal growth. For cells grown with carbon sources other than pyruvate, the major alanine-synthesizing transaminases are AvtA, YfbQ (AlaA), and YfdZ (which we designate AlaC). Growth with pyruvate as the carbon source and multicopy suppression suggest that several other transaminases can contribute to alanine synthesis. Expression studies showed that alanine modestly repressedavtAandyfbQbut had no effect onyfdZ. The leucine-responsive regulatory protein (Lrp) mediated control by alanine. We purified YfbQ and YfdZ and showed that both are dimers withKms for pyruvate within the intracellular range of pyruvate concentration.
Deficiency inl-Serine Deaminase Interferes with One-Carbon Metabolism and Cell Wall Synthesis inEscherichia coliK-12
Authors: Zhang Xiao , El-Hajj Ziad W. , Newman Elaine 
Published: August 2010

ABSTRACTEscherichia coliK-12 provided with glucose and a mixture of amino acids depletesl-serine more quickly than any other amino acid even in the presence of ammonium sulfate. A mutant without three 4Fe4Sl-serine deaminases (SdaA, SdaB, and TdcG) ofE. coliK-12 is unable to do this. The high level ofl-serine that accumulates when such a mutant is exposed to amino acid mixtures starves the cells for C1units and interferes with cell wall synthesis. We suggest that at high concentrations,l-serine decreases synthesis of UDP-N-acetylmuramate-l-alanine by themurC-encoded ligase, weakening the cell wall and producing misshapen cells and lysis. The inhibition by highl-serine is overcome in several ways: by a large concentration ofl-alanine, by overproducing MurC together with a low concentration ofl-alanine, and by overproducing FtsW, thus promoting septal assembly and also by overexpression of the glycine cleavage operon.S-Adenosylmethionine reduces lysis and allows an extensive increase in biomass without improving cell division. This suggests thatE. colihas a metabolic trigger for cell division. Without that reaction, if no other inhibition occurs, other metabolic functions can continue and cells can elongate and replicate their DNA, reaching at least 180 times their usual length, but cannot divide.
The N-Terminal Domain of
Aliivibrio fischeri
LuxR Is a Target of the GroEL Chaperonin
Authors: Manukhov Ilya V. , Melkina Ol'ga E. , Goryanin Ignatii I. , Baranova Ancha V. , Zavilgelsky Gennadii B. 
Published: August 2010

ABSTRACT

Here we show that the C-terminal domain of LuxR activates the transcription of
Aliivibrio fischeri luxICDABEG
in
Escherichia coli
SKB178
gro
+
and
E. coli
OFB1111
groEL673
strains to the same level. Using affinity chromatography, we showed that GroEL binds to the N-terminal domain of LuxR, pointing to a GroEL/GroES requirement for the folding of the N-terminal domain of LuxR.
Inactivation of a Heterocyst-Specific Invertase Indicates a Principal Role of Sucrose Catabolism in Heterocysts of
Anabaena
sp
Authors: López-Igual Rocío , Flores Enrique , Herrero Antonia 
Published: August 2010

ABSTRACT

Anabaena
sp. strain PCC 7120 is a filamentous cyanobacterium that carries out N
2
fixation in specialized cells called heterocysts, which exchange nutrients and regulators with the filament's vegetative cells that perform the photosynthetic fixation of CO
2
. The
Anabaena
genome carries two genes coding for alkaline/neutral invertases,
invA
and
invB
. As shown by Northern analysis, both genes were expressed monocistronically and induced under nitrogen deprivation, although induction was stronger for
invB
than for
invA
. Whereas expression of an InvA-N-GFP fusion (green fluorescent protein [GFP] fused to the N terminus of the InvA protein [InvA-N]) was homogeneous along the cyanobacterial filament, consistent with the lack of dependence on HetR, expression of an InvB-N-GFP fusion upon combined nitrogen deprivation took place mainly in differentiating and mature heterocysts. In an
hetR
genetic background, the InvB-N-GFP fusion was strongly expressed all along the filament. An insertional mutant of
invA
could grow diazotrophically but was impaired in
nifHDK
induction and exhibited an increased frequency of heterocysts, suggesting a regulatory role of the invertase-mediated carbon flux in vegetative cells. In contrast, an
invB
mutant was strongly impaired in diazotrophic growth, showing a crucial role of sucrose catabolism mediated by the InvB invertase in the heterocysts.
Mutational Analysis of
Bacillus megaterium
QM B1551 Cortex-Lytic Enzymes
Authors: Christie Graham , Üstok Fatma Isık , Lu Qiaozhi , Packman Len C. , Lowe Christopher R. 
Published: August 2010

ABSTRACT

Molecular-genetic and muropeptide analysis techniques have been applied to examine the function
in vivo
of the
Bacillus megaterium
QM B1551 SleB and SleL proteins. In common with
Bacillus subtilis
and
Bacillus anthracis
, the presence of anhydromuropeptides in
B. megaterium
germination exudates, which is indicative of lytic transglycosylase activity, is associated with an intact
sleB
structural gene.
B. megaterium sleB cwlJ
double mutant strains complemented with engineered SleB variants in which the predicted N- or C-terminal domain has been deleted (SleB-ΔN or SleB-ΔC) efficiently initiate and hydrolyze the cortex, generating anhydromuropeptides in the process. Additionally,
sleB cwlJ
strains complemented with SleB-ΔN or SleB-ΔC, in which glutamate and aspartate residues have individually been changed to alanine, all retain the ability to hydrolyze the cortex to various degrees during germination, with concomitant release of anhydromuropeptides to the surrounding medium. These data indicate that while the presence of either the N- or C-terminal domain of
B. megaterium
SleB is sufficient for initiation of cortex hydrolysis and the generation of anhydromuropeptides, the perceived lytic transglycosylase activity may be derived from an enzyme(s), perhaps exclusively or in addition to SleB, which has yet to be identified.
B. megaterium
SleL appears to be associated with the epimerase-type activity observed previously in
B. subtilis
, differing from the glucosaminidase function that is apparent in
B. cereus
/
B. anthracis
.
Genome Sequences of
Pelagibaca bermudensis
HTCC2601
T
and
Maritimibacter alkaliphilus
HTCC2654
T
, the Type Strains of Two Marine
Roseobacter
Genera
Authors: Thrash J. Cameron , Cho Jang-Cheon , Ferriera Steve , Johnson Justin , Vergin Kevin L. , Giovannoni Stephen J. 
Published: August 2010

ABSTRACT

Pelagibaca bermudensis
HTCC2601
T
and
Maritimibacter alkaliphilus
HTCC2654
T
represent two marine genera in the globally significant
Roseobacter
clade of the
Alphaproteobacteria
. Here, we present the genome sequences of these organisms, isolated from the Sargasso Sea using dilution-to-extinction culturing, which offer insight into the genetic basis for the metabolic and ecological diversity of this important group.
A day in the life of a junior doctor: everyday ethical encounters
Authors: Quarini Catherine J 
Published: August 2010

Abstract
This paper presents a hypothetical ‘day in the life’ of junior doctors working on a busy hospital ward. It illustrates the fact that, although the everyday ethical encounters faced by doctors are generally not as dramatic as some of the ethical issues discussed at medical school, the underlying principles, such as consent, confidentiality and resource allocation, are highly relevant to daily practice. After presenting some of the ethical challenges faced by junior doctors, from patients confused by poor explanations to inadequate consent procedures, the paper ends with suggestions on how to improve the situation.
STUDIES ON AGE HARDENING FOR IMPROVEMENT OF 6261 AND 6060 EXTRUDED ALUMINIUM ALLOYS
Authors: AU KA KI (KATIE) , HODGSON MICHAEL , PASANG TIMOTIUS , CHIU YU LUNG 
Published: August 2010

The magnesium silicide precipitates in the 6XXX series alloy are the main components contributing to the heat treatable properties and T6 strength of the alloy, which is influenced by the size, morphology and distribution of this phase. During the extrusion process, the strength contributing phase, magnesium silicide is supposed to dissolve and form again in a controlled state during age hardening. Whereas the intermetallic AlFeSi phase has little if any influence on the strength, the β phase of this intermetallic is known to cause brittle fracture of this alloy, as opposed to the less detrimental, more equiaxed α phase formed during homogenisation.This study investigates the as-extruded 6060 and the more heavily alloyed 6261 aluminium alloys, as well as the subsequent heat treated forms to investigate the ageing conditions to optimise hardening and shorten age hardening times for higher cost effectiveness. The microstructure, texture and precipitate size and distributions were studied using optical microscopy, SEM, EBSD and DSC. SEM and EDAX results have indicated signs of evenly distributed α AlFeSi and β Magnesium Silicide precipitates. The phase responsible for hardening is believed to be the much smaller scaled β" magnesium silicide, requiring much higher resolution studies.
Novel Matrix Metalloproteinase Inhibitor [18F]Marimastat-Aryltrifluoroborate as a Probe for In vivo Positron Emission Tomography Imaging in Cancer
Authors: auf dem Keller Ulrich , Bellac Caroline L. , Li Ying , Lou Yuanmei , Lange Philipp F. , Ting Richard , Harwig Curtis , Kappelhoff Reinhild , Dedhar Shoukat , Adam Michael J. , Ruth Thomas J. , Bénard François , Perrin David M. , Overall Christopher M. 
Published: August 2010

Abstract
Matrix metalloproteinases (MMP), strongly associated pathogenic markers of cancer, have undergone extensive drug development programs. Marimastat, a noncovalent MMP inhibitor, was conjugated with FITC to label cellular metalloproteinase cancer targets in MDA-MB-231 cells in vitro. Punctate localization of active transmembrane MMP14 was observed. For molecular-targeted positron emission tomography imaging of syngeneic 67NR murine mammary carcinoma in vivo, marimastat was 18F-labeled using a shelf-stable arylboronic ester conjugate as a captor for aqueous [18F]fluoride in a novel, rapid one-step reaction at ambient temperature. [18F]Marimastat-aryltrifluoroborate localized to the tumors, with labeling being blocked in control animals first loaded with &gt;10-fold excess unlabeled marimastat. The labeled drug cleared primarily via the hepatobiliary and gastrointestinal tract, with multiple animals imaged in independent experiments, confirming the ease of this new labeling strategy. Cancer Res; 70(19); 7562–9. ©2010 AACR.
Ergonomic Factors Related to Drop-Off Detection With the Long Cane: Effects of Cane Tips and Techniques
Authors: Kim Dae Shik , Wall Emerson Robert S. , Curtis Amy B. 
Published: August 2010

Objective: This study examined the effect of cane tips and cane techniques on drop-off detection with the long cane. Background: Blind pedestrians depend on a long cane to detect drop-offs. Missing a drop-off may result in falls or collision with moving vehicles in the street. Although cane tips appear to affect a cane user’s ability to detect drop-offs, few experimental studies have examined such effect. Method: A repeated-measures design with block randomization was used for the study. Participants were 17 adults who were legally blind and had no other disabilities. Participants attempted to detect the drop-offs of varied depths using different cane tips and cane techniques. Results: Drop-off detection rates were similar between the marshmallow tip (77.0%) and the marshmallow roller tip (79.4%) when both tips were used with the constant contact technique, p = .294. However, participants detected drop-offs at a significantly higher percentage when they used the constant contact technique with the marshmallow roller tip (79.4%) than when they used the two-point touch technique with the marshmallow tip (63.2%), p < .001. Conclusion: The constant contact technique used with a marshmallow roller tip (perceived as a less advantageous tip) was more effective than the two-point touch technique used with a marshmallow tip (perceived as a more advantageous tip) in detecting drop-offs. Application: The findings of the study may help cane users and orientation and mobility specialists select appropriate cane techniques and cane tips in accordance with the cane user’s characteristics and the nature of the travel environment.
Hand and Finger Dexterity as a Function of Skin Temperature, EMG, and Ambient Condition
Authors: Chen Wen-Lin , Shih Yuh-Chuan , Chi Chia-Fen 
Published: August 2010

Objective: This article examines the changes in skin temperature (finger, hand, forearm), manual performance (hand dexterity and strength), and forearm surface electromyograph (EMG) through 40-min, 11 °C water cooling followed by 15-min, 34 °C water rewarming; additionally, it explores the relationship between dexterity and the factors of skin temperature, EMG, and ambient condition. Background: Hand exposure in cold conditions is unavoidable and significantly affects manual performance. Method: Two tasks requiring gross and fine dexterity were designed, namely, nut loosening and pin insertion, respectively. The nested-factorial design includes factors of gender, participant (nested within gender), immersion duration, muscle type (for EMG), and location (for skin temperature). The responses are changes in dexterity, skin temperature, normalized amplitude of EMG, and grip strength. Finally, factor analysis and stepwise regression are used to explore factors affecting hand and finger dexterity. Results: Dexterity, EMG, and skin temperature fell with prolonged cooling, but the EMG of the flexor digitorum superficialis remained almost unchanged during the nut loosening task. All responses but the forearm skin temperature recovered to the baseline level at the end of rewarming. The three factors extracted by factor analysis are termed skin temperature, ambient condition, and EMG. They explain approximately two thirds of the variation of the linear models for both dexterities, and the factor of skin temperature is the most influential. Conclusion: Sustained cooling and warming significantly decreases and increases finger, hand, and forearm skin temperature. Dexterity, strength, and EMG are positively correlated to skin temperature. Therefore, keeping the finger, hand, and forearm warm is important to maintaining hand performance. Application: The findings could be help- ful to building safety guidelines for working in cold environments.
Are Patients’ Initial Experiences at the Diagnosis of Type 2 Diabetes Associated With Attitudes and Self-management Over Time?
Authors: Polonsky William H. , Fisher Lawrence , Guzman Susan , Sieber William J. , Philis-Tsimikas Athena , Edelman Steven V. 
Published: August 2010

Objective The purpose of this study was to investigate patients’ experiences when diagnosed with type 2 diabetes and diabetes-related distress and self-management years later. Method One hundred seventy-nine adults with type 2 diabetes, 1 to 5 years after diagnosis, completed a questionnaire assessing what they were told and what was recommended at diagnosis as well as current diet, physical activity, and diabetes distress. Results Most patients (60%) expressed confidence in their health care provider (HCP) at diagnosis, but 30% reported that a clear action plan was not communicated. Current diabetes distress was significantly lower among those who reported being reassured at diagnosis that diabetes could be managed successfully and had developed a clearer action plan with their HCP. Patients’ current dietary behaviors were significantly better among those receiving a clearer action plan at diagnosis. Conclusion Patients’ retrospective reports of reassuring HCP messages when diagnosed, along with the presentation of a clear action plan, are associated with less diabetes distress and better self-management at 1 to 5 years after diagnosis. Practical implications Findings suggest a long-lasting impact on patients’ attitudes and behaviors when the diagnosis of type 2 diabetes is delivered clearly, a sense of hope is provided, and a specific care plan is put forward.
Abiomed Impella ® 2.5 patient transport: lessons learned
Authors: Griffith Kevin E , Jenkins Eric 
Published: August 2010

The Abiomed Impella ® 2.5 is a micro-axial flow, catheter-based left ventricular assist system (LVAS). Designed for percutaneous insertion into the femoral artery and positioned across the aortic valve, the Impella® is capable of pumping 2.5 liters of blood per minute from the patient’s left ventricle into the ascending aorta. Since United States Federal Food and Drug Administration clearance in June of 2008, use of the Impella® 2.5 has grown rapidly. We operate at the center of a “hub-and-spoke” regional referral network that facilitates the transfer of patients in cardiogenic shock to our facility for definitive care. Based on our recent experience of transporting patients supported on the Impella® 2.5 system, we review system operation, pump position, monitoring, and recommendations for providing safe and efficient transport.
Relevance of cognitive deterioration in early relapsing-remitting MS: a 3-year follow-up study
Authors: Amato Maria P , Portaccio Emilio , Goretti Benedetta , Zipoli Valentina , Iudice Alfonso , Pina Dario Della , Malentacchi Gianmichele , Sabatini Simonetta , Annunziata Pasquale , Falcini Mario , Mazzoni Monica , Mortilla Marzia , Fonda Claudio , De Stefano Nicola ,   TuSCIMS Study Group
Published: August 2010

Objective: To assess longitudinally cognitive functioning in relapsing—remitting multiple sclerosis (RRMS) patients and its relationship with clinical and MRI variables. Methods: Early RRMS patients and matched healthy controls were assessed in parallel in three testing sessions over 3 years, using the Rao’s Brief Repeatable Battery of Neuropsychological Tests. Patients also underwent an MRI analysis of T2-weighted lesion volume (T2LV), number of gadolinium-enhanced lesions and whole brain atrophy. Forty-nine RRMS patients (mean age 36.9 ± 8.9 years; mean disease duration 2.9 ± 1.7 years, mean Expanded Disability Status Scale, 1.7 ± 0.7) and 56 healthy controls were recruited. Results: At baseline, cognitive impairment was detected in 15 patients (30.6%). After 3 years, cognitive functioning worsened in the 29.3% of patients, whereas Expanded Disability Status Scale progression was observed in only three patients. The most sensitive test to detect cognitive deterioration over time was the Symbol Digit Modalities Test (SDMT). Only the presence of moderate cognitive impairment at baseline predicted further cognitive deterioration ( p = 0.03). Among MRI variables, T2LV showed a weak to moderate relationship with some cognitive tasks. Conclusions: Over a 3-year period cognitive deterioration can be expected in approximately one-third of MS patients with relatively short disease duration. The SDMT is particularly suitable for longitudinal assessment of MS-related cognitive changes.
Cancer registries: a novel alternative to long-term clinical trial follow-up based on results of a comparative study
Authors: Qian Shi  , You Y Nancy , Nelson Heidi , Allen Mark S , Winchester David , Stewart Andrew , Young-Fadok Tonia , Decker Paul A , Green Erin M , Holton Sara J , Ballman Karla V 
Published: August 2010

Background Data collection and review were identified as major contributors to the cost of randomized clinical trials (RCTs). Purpose We proposed and assessed a novel alternative for long-term clinical trial follow-up based on the data captured through an accredited Cancer Registry (CR) that is part of the National Cancer Database (NCDB). Methods Patients from Mayo Clinic, Rochester, enrolled in the North Central Cancer Treatment Group N934653 (COST) trial (98 patients) and the American College of Surgeons Oncology Group Z0030 trial (55 patients) were included in the study. Demographic, treatment, and long-term outcome data were compared between the hospital-based CR and the RCTs’ databases. Concordances were used to estimate the agreement between two databases. Kaplan—Meier curves were plotted to examine the consistency of time-to-event long-term outcomes of the CR and RCT databases. Results High concordances (>95%) were observed for most demographic and treatment variables between the CR data and RCT data. The vital status concordances were 100% and 94.5% between the CR and COST and Z0030 databases, respectively. Three discrepant death dates were observed, one in the COST trial and two in the Z0030 trial. The concordances of disease-free status between the CR and RCT databases were 99.0% and 87.3%, and 15 discrepant disease recurrence cases were identified: 4 for COST and 11 for Z0030. Limitations The analysis has been focused on patients from a single site, Mayo Clinic, Rochester, enrolled in two large RCT evaluating surgical treatments. The findings herein need to be confirmed in a broader setting, such as multi-center, multi-registry including nonsurgical trials. Conclusions CR data were nearly identical to data from two randomized phase III trials in different disease types and conducted by two different cooperative groups. The NCDB Cancer Registries represent a feasible alternative for obtaining long-term follow-up data for large clinical trials. Clinical Trials 2010; 7: 686—695. http:// ctj.sagepub.com
Efficacy of a synbiotic supplementation in the prevention of common winter diseases in children: a randomized, double-blind, placebo-controlled pilot study
Authors: Cazzola Mario , Pham-Thi Nhân , Kerihuel Jean-Charles , Durand Henri , Bohbot Serge 
Published: August 2010

Background and aims: The purpose of this study was to investigate the efficacy of a synbiotic supplementation in reducing common winter diseases in children. Methods: A randomized, double-blind, placebo-controlled, multicentre study was conducted in young school-age children (3—7 years old) during a winter period. Participants were otherwise healthy children who suffered from at least three episodes of ear, nose and throat (ENT), respiratory tract or gastrointestinal illness during the previous winter. They were supplemented daily with either a synbiotic preparation (Lactobacillus helveticus R0052, Bifidobacterium infantis R0033, Bifidobacterium bifidum R0071, and fructooligosaccharide) or a matched placebo for 3 months. Over this period, all emergent health episodes of any type were recorded by parents in a diary. They were checked by investigators at regular monthly visits. The main study outcome was the percentage of children free of any episode during the study course. Results: We randomized 135 children (mean age: 4.1±1.0 years) to the synbiotic group ( n = 62) or placebo ( n = 73) group. At least one illness episode was reported in 32 children in the synbiotic group and 50 in the placebo group (51.6% versus 68.5%). This corresponded to a significant 25% relative risk reduction (95% CI 0.6—44.3%; p = 0.045). This difference was due to a decrease in the number of children who suffered from at least one ENT, respiratory tract or gastrointestinal disorder (50.0% with synbiotic versus 67.1% with placebo; p = 0.044). At least one sickness school day loss was noted in 25.8% of children with the synbiotic as compared with 42.5% with placebo ( p = 0.043). No treatment related side effects were detected in either group. Conclusions: This study suggests that a 3-month supplementation with this synbiotic preparation can decrease the risk of occurrence of common infectious diseases in children and limits the risk of school day loss.