bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vivo Characterization of
Escherichia coli ftsZ
Mutants: Effects on Z-Ring Structure and Function
Authors: Stricker Jesse , Erickson Harold P. 
Published: August 2003

ABSTRACT

We have characterized the in vivo phenotypes of 17 mutations of
Escherichia coli ftsZ
. In particular, we determined whether these mutations can complement a null
ftsZ
phenotype, and we demonstrated that two noncomplementing mutations show partial dominant-negative behavior. We performed immunofluorescence microscopy to determine whether these mutants could assemble into normal or abnormal structures in vivo. The mutants separated into four classes—those that complemented the null and formed normal FtsZ rings, those that complemented the null but formed aberrant FtsZ structures, those that formed aberrant FtsZ structures and did not complement, and those that were unable to form any FtsZ structures. We did not find any mutations that produced nonfunctional Z rings of normal appearance. Surprisingly, some mutants that produced extensively spiraled Z-ring structures divided and grew with a normal doubling time. The analysis was carried out using a complementation system based on an
ftsZ
deletion strain, a temperature-sensitive rescue plasmid, and a complementation vector that placed mutated
ftsZ
alleles under the control of the pBAD promoter, which offered several advantages over previous systems.
Molecular Analysis of Phr Peptide Processing inBacillus subtilis
Authors: Stephenson Sophie , Mueller Christian , Jiang Min , Perego Marta 
Published: August 2003

ABSTRACTInBacillus subtilis, an export-import pathway regulates production of the Phr pentapeptide inhibitors of Rap proteins. Processing of the Phr precursor proteins into the active pentapeptide form is a key event in the initiation of sporulation and competence development. The PhrA (ARNQT) and PhrE (SRNVT) peptides inhibit the RapA and RapE phosphatases, respectively, whose activity is directed toward the Spo0F∼P intermediate response regulator of the sporulation phosphorelay. The PhrC (ERGMT) peptide inhibits the RapC protein acting on the ComA response regulator for competence with regard to DNA transformation. The structural organization of PhrA, PhrE, and PhrC suggested a role for type I signal peptidases in the processing of the Phr preinhibitor, encoded by thephrgenes, into the proinhibitor form. The proinhibitor was then postulated to be cleaved to the active pentapeptide inhibitor by an additional enzyme. In this report, we provide evidence that Phr preinhibitor proteins are subject to only one processing event at the peptide bond on the amino-terminal end of the pentapeptide. This processing event is most likely independent of type I signal peptidase activity. In vivo and in vitro analyses indicate that none of the five signal peptidases ofB. subtilis(SipS, SipT, SipU, SipV, and SipW) are indispensable for Phr processing. However, we show that SipV and SipT have a previously undescribed role in sporulation, competence, and cell growth.
Temperature-Dependent Hypermutational Phenotype inrecAMutants ofThermus thermophilusHB27
Authors: Castán Pablo , Casares Lorena , Barbé Jordi , Berenguer José 
Published: August 2003

ABSTRACTTherecAgene fromThermus thermophilusHB27 was cloned and engineered to obtain insertion (recA::kat) and deletion (ΔrecA) derivatives. Transcription ofrecAin this extreme thermophile was induced by mitomycin C, leading to the synthesis of a monocistronic mRNA. This DNA damage-mediated induction was dependent on the integrity ofrecA.In addition to UV sensitivity, therecAmutants ofT. thermophilusshowed severe pleiotropic defects, ranging from irregular nucleoid condensation and segregation to a dramatic reduction in viability during culture. An increase in the frequency of both carotenoidless and auxotrophic mutants within surviving cells of the ΔrecAstrain indicated a high mutation rate. As RecA is not required for plasmid transformation, we have used the α-lacZgene fragment and the ampicillin resistance gene fromEscherichia colias passenger reporters to confirm such high mutation rates. Our data support the idea that the absence of RecA results in a hypermutational phenotype inT. thermophilus. Furthermore, a direct relationship is deduced between the growth temperature and mutation rate, which finally has a deleterious effect on cell survival in the absence of RecA.
ABurkholderia pseudomalleiType III Secreted Protein, BopE, Facilitates Bacterial Invasion of Epithelial Cells and Exhibits Guanine Nucleotide Exchange Factor Activity
Authors: Stevens Mark P. , Friebel Andrea , Taylor Lowrie A. , Wood Michael W. , Brown Philip J. , Hardt Wolf-Dietrich , Galyov Edouard E. 
Published: August 2003

ABSTRACTWe report the characterization of BopE, a type III secreted protein that is encoded adjacent to theBurkholderia pseudomallei bsalocus and is homologous toSalmonellaentericaSopE/SopE2. Inactivation ofbopEimpaired bacterial entry into HeLa cells, indicating that BopE facilitates invasion. Consistent with this notion, BopE expressed in eukaryotic cells induced rearrangements in the subcortical actin cytoskeleton, and purified BopE exhibited guanine nucleotide exchange factor activity for Cdc42 and Rac1 in vitro.
ThepstOperon ofBacillus subtilisIs Specifically Induced by Alkali Stress
Authors: Atalla Akram , Schumann Wolfgang 
Published: August 2003

ABSTRACTTo cope with a sudden increase in the external pH value to 8.9,Bacillus subtiliscells induce about 80 genes which can be divided into two classes. Most of these genes are members of the σWregulon, while some are under the control of so-far-unknown transcriptional regulators. The genes of thepstoperon belong to the second class. Here, we attempted to answer the questions of why and how the genes of this operon are induced. Using transcriptional fusions to two of the five genes of this operon, we confirmed their induction after alkali stress. Furthermore, a Northern blot experiment revealed that the complete operon was alkali inducible, that the transcriptional start site used was identical to that used after phosphate starvation, and that induction was prevented in aphoRbackground. Most interestingly, increasing the phosphate concentration within the medium prevented alkali induction of thepstoperon, andphoA, another member of the PhoRP regulon, did not respond to alkali stress. In the end, we showed that alkali treatment completely prevented phosphate uptake. These results are discussed to explain alkali induction of thepstoperon.
Conversion of
Lactobacillus pentosus
d
-Lactate Dehydrogenase to a
d
-Hydroxyisocaproate Dehydrogenase through a Single Amino Acid Replacement
Authors: Tokuda Chizuka , Ishikura Yoshiro , Shigematsu Mayu , Mutoh Hiroyuki , Tsuzuki Shino , Nakahira Yusaku , Tamura Yusuke , Shinoda Takeshi , Arai Kazuhito , Takahashi O , Taguchi Hayao 
Published: August 2003

ABSTRACT

The single amino acid replacement of Tyr52 with Leu drastically increased the activity of
Lactobacillus pentosus
NAD-dependent
d
-lactate dehydrogenase toward larger aliphatic or aromatic 2-ketoacid substrates by 3 or 4 orders of magnitude and decreased the activity toward pyruvate by about 30-fold, converting the enzyme into a highly active
d
-2-hydroxyisocaproate dehydrogenase.
Recombinant erythropoietin in clinical practice
Authors: Ng T , Marx G , Littlewood T , Macdougall I 
Published: August 2003

Abstract
The introduction of recombinant human erythropoietin (RHuEPO) has revolutionised the treatment of patients with anaemia of chronic renal disease. Clinical studies have demonstrated that RHuEPO is also useful in various non-uraemic conditions including haematological and oncological disorders, prematurity, HIV infection, and perioperative therapies. Besides highlighting both the historical and functional aspects of RHuEPO, this review discusses the applications of RHuEPO in clinical practice and the potential problems of RHuEPO treatment.
Acute and chronic arsenic toxicity
Authors: Ratnaike R N 
Published: August 2003

Abstract
Arsenic toxicity is a global health problem affecting many millions of people. Contamination is caused by arsenic from natural geological sources leaching into aquifers, contaminating drinking water and may also occur from mining and other industrial processes. Arsenic is present as a contaminant in many traditional remedies. Arsenic trioxide is now used to treat acute promyelocytic leukaemia. Absorption occurs predominantly from ingestion from the small intestine, though minimal absorption occurs from skin contact and inhalation. Arsenic exerts its toxicity by inactivating up to 200 enzymes, especially those involved in cellular energy pathways and DNA synthesis and repair. Acute arsenic poisoning is associated initially with nausea, vomiting, abdominal pain, and severe diarrhoea. Encephalopathy and peripheral neuropathy are reported. Chronic arsenic toxicity results in multisystem disease. Arsenic is a well documented human carcinogen affecting numerous organs. There are no evidence based treatment regimens to treat chronic arsenic poisoning but antioxidants have been advocated, though benefit is not proven. The focus of management is to reduce arsenic ingestion from drinking water and there is increasing emphasis on using alternative supplies of water.
Single megadose vitamin A supplementation of Indian mothers and morbidity in breastfed young infants
Authors: Basu S , Sengupta B , Paladhi P K Roy 
Published: August 2003

Abstract

Background and objective
In developing countries low maternal vitamin A stores combined with increased demands of pregnancy and lactation may lead to its deficiency in breastfed infants. This study evaluates the effects of maternal supplementation with a high dose of vitamin A on the serum retinol levels of exclusively breastfed infants, and their morbidity in the first six months of life.

Setting
Hospital based.

Study design
Randomised controlled trial.

Subjects and methods
Mothers of the test group (n=150) were orally supplemented with a single dose of retinol (209 μmol) soon after delivery and were advised exclusive breastfeeding for six months. Before supplementation retinol levels were estimated in the mothers’ and newborns’ blood, and in colostrum. On follow up, breastmilk and infants’ serum retinol contents were assessed monthly for six months. Retinol level &lt;0.7 μmol/l indicated vitamin A deficiency. Morbidity patterns like vitamin A deficiency, diarrhoea, febrile illnesses, acute respiratory infection, measles, and ear infection were also studied and compared between the two groups.

Results
Presupplement mean maternal serum retinol levels were 0.98 and 0.92 μmol/l and mean breastmilk levels were 3.85 and 3.92 μmol/l in the test and control groups respectively (p&gt;0.05). Mean cord blood retinol levels were also comparable (0.68 v 0.64 μmol/l). After supplementation, the test group showed a rise in mean breastmilk retinol content (12.08 v 2.96 μmol/l) which remained significantly higher for four months. The infants’ mean serum retinol level, initially 322.06% of the baseline value, was significantly higher for five months. In the control group, significant numbers of mothers and infants showed deficient breastmilk and serum retinol throughout the follow up (p&lt;0.01). Decreased incidence and duration of various diseases were also found in the test group suggesting lesser morbidity.

Conclusion
Maternal supplementation with single megadose vitamin A is an effective strategy for vitamin A prophylaxis of exclusively breastfed infants of 0–6 months.
Brain volume, asymmetry and intellectual impairment in relation to sex in early-onset schizophrenia
Authors: Collinson Simon L. , Mackay Clare E. , James Anthony C. , Quested Digby J. , Phillips Tania , Roberts Neil , Crow Timothy J. 
Published: August 2003

BackgroundAccumulating evidence suggests that early-onset schizophrenia arises from a disturbance in the normal trajectory of cerebral development.AimsTo investigate brain structure, asymmetry and IQ in early-onset schizophrenia.MethodVolumes of left and right cerebral hemispheres and IQ were assessed in 33 participants with early-onset DSM – IV schizophrenia and 30 members of a matched, normal control group.ResultsTotal brain volume was significantly smaller in the group with early-onset disease (‘cases’) relative to the control group (4.5%), especially for the left hemisphere in males (6.0%). A significant sex x diagnosis interaction in hemisphere asymmetry revealed that the female cases group had significantly reduced rightward asymmetry relative to the female control group and that the male cases tended to have reduced leftward asymmetry relative to the male control group. Decreased left hemisphere volume in males and decreased rightward hemispheric asymmetry in females correlated with reduced IQ.ConclusionsSexually dimorphic alterations in asymmetry correlate with degree of intellectual impairment in early-onset schizophrenia.
Assertive outreach teams in London: Staff experiences and perceptions
Authors: Billings Joanne , Johnson Sonia , Bebbington Paul , Greaves Adele , Priebe Stefan , Muijen Matt , Ryrie Iain , Watts Joanna , White Ian , Wright Christine 
Published: August 2003

BackgroundThe job satisfaction, burn-out and work experiences of assertive outreach team staff are likely to be important to the model's sustainability.AimsTo describe self-reported views and workexperiences of staff in London's 24 assertive outreach teams and to compare these with staff in community mental health teams (CMHTs) and between different types of assertive outreach team.MethodConfidential staff questionnaires in London's assertive outreach teams (n=l87, response rate= 89%) and nine randomly selected CMHTs (n=114, response rate=75%).ResultsStaff in assertive outreach teams and CMHTs were moderately satisfied with their jobs, with similar sources of satisfaction and stress. Mean scores were low or average for all sub-scales of the Maslach Burnout Inventory for the assertive outreach team and the CMHT staff, with some differences suggesting less burn-out in the assertive outreach teams. Nine of the 24 assertive outreach teams had team means in the high range for emotional exhaustion and there were significant differences between types of assertive outreach team in some components of burn-out and satisfaction.ConclusionsThese findings are encouraging, but repeated investigation is needed when assertive outreach teams have been established for longer.
Suicides in ethnic minorities within 12 months of contact with mental health services
Authors: Hunt Isabelle M. , Robinson Jo , Bickley Harriet , Meehan Janet , Parsons Rebecca , McCann Kerry , Flynn Sandra , Burns James , Shaw Jenny , Kapur Navneet , Appleby Louis 
Published: August 2003

BackgroundInformation on suicide by psychiatric patients from ethnic minority groups is scarce.AimsTo establish the number of patients from ethnic minorities who kill themselves; to describe their suicide methods, and their social and clinical characteristics.MethodA national clinical survey was based on a 4-year sample of suicides in England and Wales. Detailed data were collected on those who had been in contact with mental health services in the year before death.ResultsIn total 282 patients from ethnic minorities died by suicide – 6% of all patient suicides. The most common method of suicide was hanging; violent methods were more common than in White patient suicides. Schizophrenia was the most common diagnosis. Ethnic minority patients were more likely to have been unemployed than White patients and to have had a history of violence and recent non-compliance. In around half, this was the first episode of self-harm. Black Caribbean patients had the highest rates of schizophrenia (74%), unemployment, living alone, previous violence and drug misuse.ConclusionsIn order to reduce the number of suicides byethnicminority patients, services should address the complex health and social needs of people with severe mental illness.
Psychological and emotional problems in staff following assaults by patients
Authors: Wildgoose Joanna , Briscoe Martin , Lloyd Keith 
Published: August 2003

Aims and MethodTo determine psychological morbidity among staff following actual or threatened violence from patients on acute psychiatric wards. A retrospective survey of all 156 clinical staff on Exeter's acute psychiatric wards was conducted by means of an anonymous questionnaire using standardised measures.ResultsThe response rate was 81%, and 72% of respondents had experienced one or more distressing incidents of actual or threatened violence within the previous year. The 12-item General Health Questionnaire and Impact of Events Scale scores were significantly higher in those who reported exposure to ‘frequent’ violent incidents.Clinical ImplicationsSome National Health Service staff may be harmed psychologically when they are at work. This consequently may have implications for patient care, employer liability and recruitment.
Engaging patients as teachers of clinical interview skills
Authors: Ikkos George 
Published: August 2003

Aims and MethodTo engage patients as teachers of psychiatrists in training and non-consultant career grades, for the purpose of enhancing doctors' understanding of the patient point of view and of the complexity of the doctor–patient relationship. Patients have been engaged as teachers in a recurrent cycle of ‘Basic Interview Skills' workshops and the views of the doctors about this initiative have been elicited through a brief anonymous and confidential questionnaire.ResultsThirty-six psychiatric senior house officers (SHOs), general practitioners, Vocational Training Scheme SHOs in psychiatry, and staff grade and trust doctors in psychiatry have participated in four cycles of workshops. Five patients have engaged in the workshops as teachers, alongside the clinical tutor. Questionnaire feedback indicated some specific criticisms of a number of participants and dissatisfaction by a small minority of doctors, but the overall evaluation of the experience was positive.Clinical ImplicationsEngagement of patients as teachers of psychiatrists in training and other new doctors in mental health services is desirable, feasible and welcomed by most doctors. With due attention to the legitimate sensitivities of participants, the practice of engaging patients as teachers of doctors working in psychiatry could be generalised in training schemes and services across the country.
Interrater Reliability of Criteria Used in Assessing Blunt Head Injury Patients for Intracranial Injuries
Authors: Hollander Judd E. , Go Steven , Lowery Douglas W. , Wolfson Allan B. , Pollack Charles V. , Herbert Mel , Mower William R. , Hoffman Jerome R. 
Published: August 2003

Abstract Objective: To determine the interrater reliability of potential predictor variables that may be used to construct a clinical decision rule for emergency computed tomography of the head in blunt head injury victims. Methods: As a substudy of the NEXUS II study of blunt head trauma, physicians from 21 different emergency departments performed paired evaluations of patients undergoing computed tomography of the head after blunt head injury. Each physician independently determined, for each subject, the presence or absence of each of 19 separate clinical characteristics. The physicians were either residents or attending physicians in the participating emergency departments. Paired responses on a sample of 3,951 patients were compared for raw level of agreement and for interrater concordance using the κ statistic. If the lower margin of the 95% confidence interval for raw agreement was at least 85% and was equal to or greater than 0.50 for κ, this was predetermined to represent substantial interrater agreement. Results: There was substantial interobserver agreement by both measures for 17 of the 19 candidate variables in patients with blunt head trauma. Interobserver agreement was substantial for all candidate variables except presence of seizure (κ= 0.57 [95% CI = 0.47 to 0.67]; raw agreement = 96.5%) and abnormal cerebellar function (κ= 0.54 [95% CI = 0.41 to 0.67]; raw agreement = 96.5%). Conclusions: The clinicians in our study had a substantial level of agreement regarding most clinical criteria assessed in this large sample of patients with blunt head injury.
Advanced Statistics: Applying Statistical Process Control Techniques to Emergency Medicine: A Primer for Providers
Authors: Callahan Charles D. , Griffen David L. 
Published: August 2003

AbstractEmergency medicine faces unique challenges in the effort to improve efficiency and effectiveness. Increased patient volumes, decreased emergency department (ED) supply, and an increased emphasis on the ED as a diagnostic center have contributed to poor customer satisfaction and process failures such as diversion/bypass. Statistical process control (SPC) techniques developed in industry offer an empirically based means to understand our work processes and manage by fact. Emphasizing that meaningful quality improvement can occur only when it is exercised by “front‐line” providers, this primer presents robust yet accessible SPC concepts and techniques for use in today's ED.
Assessment for Deaths in Out‐of‐hospital Heroin Overdose Patients Treated with Naloxone Who Refuse Transport
Authors: Vilke Gary M. , Sloane Christian , Smith Alan M. , Chan Theodore C. 
Published: August 2003

AbstractNaloxone frequently is used to treat suspected heroin and opioid overdoses in the out‐of‐hospital setting. The authors' emergency medical services system has operated a policy of allowing these patients, when successfully treated, to sign out against medical advice (AMA) in the field. Objectives: To evaluate the safety of this AMA policy. Methods: This is a retrospective review of out‐of‐hospital and medical examiner (ME) databases over a five‐year period. The authors reviewed all ME cases in which opioid overdoses were listed as contributing to the cause of death. These cases were cross‐compared with all patients who received naloxone by field paramedics and then refused transport. The charts were reviewed by dates, times, age, sex, location, and ethnicity when available. Results: There were 998 out‐of‐hospital patients who received naloxone and refused further treatment and 601 ME cases of opioid overdose deaths. When compared by age, time, date, sex, location, and ethnicity, there were no cases in which a patient was treated by paramedics with naloxone within 12 hours of being found dead of an opioid overdose. Conclusions: Giving naloxone to patients with heroin overdoses in the field and then allowing them to sign out AMA resulted in no identifiable deaths within this study population.