bluuebunny/crossref_metadata_2025 huggingface dataset:
Managerial support of community mental health nurses
Authors: Funakoshi Akiko , Miyamoto Yuki , Kayama Mami
Published: May 2007

Title. Managerial support of community mental health nurses.

Aims.  This paper is a report of a study to describe the support behaviours practised by managers of community mental health nurses (CMHNs) who provide homecare for people with mental illness, and to identify factors related to those behaviours.

Background.  Homecare of mentally ill clients can prevent hospital readmission, provide rehabilitation, and include support for medication adherence, personal relationships, mental health, activities of daily living, as well as supporting informal caregivers. However, this work is stressful for CMHNs, who can themselves develop mental health problems and suffer burnout. Therefore support for these nurses is essential.

Method.  Semi‐structured interviews were conducted with 10 nurse managers in 2004. A constant comparative data collection and analysis process was used, and a core category identified.

Findings.  Four categories of managerial support behaviour were identified: (1) ‘modifying client–nurse relationships’; (2) ‘ensuring community mental health nurse safety’; (3) ‘providing emotional support’; (4) ‘providing opportunities for skill development’. ‘To continue homecare for clients in need’ emerged as a core category, representing the ultimate purpose of managerial support behaviours. Moreover, the timing of managerial support behaviours was influenced by the quality and length of the client–nurse relationship.

Conclusion.  The managerial support behaviours reported in the present study may be useful in other cultural contexts. Further research is needed to evaluate their effectiveness for CMHNs in other settings in Japan and other countries.
A model of job satisfaction of nurses: a reflection of nurses’ working lives in Mainland China
Authors: Lu Hong , While Alison E. , Louise Barriball K.
Published: May 2007

Title.  A model of job satisfaction of nurses: a reflection of nurses’ working lives in Mainland China

Aim.  This paper is a report of a study exploring nurses’ views and experience regarding their working lives in Mainland China.

Background.  The widespread nursing shortage and high turnover has become a global issue. Job satisfaction among nurses is a key factor in nurse turnover. Although several models of job satisfaction have been suggested in Western countries, these require further development and testing in Mainland China, where the social context of the labour market is different.

Method.  A survey design using questionnaires was adopted. A total of 512 hospital nurses in Beijing participated in the study in 2004, representing a response rate of 81%.

Findings.  There was a negative relationship between nurses’ job satisfaction and intention to leave their current hospitals, which was mediated by age (P < 0·05). About 40% of the variance in job satisfaction could be explained by the set of independent variables including organizational commitment, occupational stress, professional commitment, role conflict, role ambiguity, educational level, age and working years (R2 = 0·396). Organizational commitment had the strongest impact on job satisfaction, which explained 31·3% of the variance in this, followed by occupational stress and role conflict (5·5% and 1·9% respectively). In addition, both nurses’ role perception and actual role content influenced job satisfaction as well as occupational stress, role conflict and role ambiguity (P < 0·05). Nurses’ educational level was also a factor related to role perception, professional commitment and role conflict (P < 0·05).

Conclusion.  Nurses’ job satisfaction could be increased through promoting organizational and professional commitment and reducing occupational stress, role conflict and role ambiguity.
Perspectives of homeless people on their health and health needs priorities
Authors: Daiski Isolde
Published: May 2007

Title. Perspectives of homeless people on their health and health needs priorities

Aim. This paper is a report of a study of the perspectives of homeless individuals on their health and healthcare needs.

Background. Many studies show the high incidence and severity of diseases, physical and mental, amongst the homeless populations. However, the views of homeless people themselves are usually omitted. In order to provide appropriate care, healthcare professionals need to be aware of these perspectives.

Method. A descriptive, exploratory design, using semi‐structured interviews and observational field notes, was chosen for this qualitative study. A convenience sample of 24 participants experiencing homelessness was recruited in one Canadian city in 2005.

Findings. Participants described their health and healthcare needs in a holistic sense. They reported concerns about physical illnesses, mental health, addictions and stress. Shelter life promoted spread of diseases and lacked privacy. Violence was rampant in shelters and on the streets, leading to constant fear. There was emotional distress over social exclusion and depersonalization. Participants wanted to work and to be housed, yet felt trapped in a dehumanizing system.

Conclusion. The recommendations are (a) elimination or mitigation of most health problems of the homeless through safe, affordable housing; (b) reintegration into the community through job counselling, treatment of addictions and employment. Negative societal attitudes towards these clients need to change. Healthcare professionals, particularly community nurses, have opportunities to collaborate respectfully with these clients and work for changes in public policies, such as national housing and addiction treatment policies, and for streamlined, humanized services to smooth the processes of social reintegration.
Against the odds: experiences of nurse leaders in Clinical Development Units (Nursing) in Australia
Authors: Atsalos Christine , O'Brien Louise , Jackson Debra
Published: May 2007

Title. Against the odds: experiences of nurse leaders in Clinical Development Units (Nursing) in Australia

Aim.  This paper is a report of a longitudinal study to develop an understanding of the phenomena of Clinical Development Unit (Nursing) leadership by exploring the experiences of the nurse leaders of nine Australian units as they attempted to develop their existing wards or units into recognized centres of nursing excellence.

Background.  The concept of Clinical Development Unit (Nursing) in Australia originated in the British Nursing Development Unit movement, which has been widely credited with introducing innovative approaches to developing nurses and nursing. A network of nine Clinical Development Units (Nursing) was set up in a suburban area health service in Australia. The aim was to develop existing wards or units into centres of excellence by disseminating a new vision for Australian nurses that was based on the pioneering work of the British Nursing Development Unit movement.

Methodology.  Principles of Heideggerian hermeneutic phenomenology provided a framework for the study. Nine Clinical Development Unit (Nursing) leaders participated in qualitative interviews from 1998 to 2002. These interviews were transcribed into text and thematically analysed.

Findings.  Despite attempts to implement a variety of measures to nurture these Clinical Development Units (Nursing) until they had become well established, the new Clinical Development Unit (Nursing) leaders were unable to maintain the Clinical Development Unit (Nursing) vision with which they had been entrusted. This paper discusses their reactions to the problems they faced and the new understandings they developed of their Clinical Development Unit (Nursing) role over time.

Conclusion.  The findings illuminate the difficulties involved in maintaining the commitment of all levels of staff and management when attempting to introduce new nursing projects.
Factors facilitating and inhibiting evidence‐based nursing in Iran
Authors: Adib‐Hajbaghery Mohsen
Published: May 2007

Title. Factors facilitating and inhibiting evidence‐based nursing in Iran

Aim.  This paper is a presentation of a study to clarify the concept of evidence‐based nursing and to explore the factors that influence evidence‐based nursing by Iranian nurses.

Background.  Evidence‐based practice was introduced as an approach to high‐quality care intended to improve results for patients. Several nurse researchers have studied factors affecting implementation of evidence‐based nursing in western countries. However, there is little or no research on the perceptions of evidence‐based nursing and its barriers in eastern countries, especially Iran.

Methodology.  Grounded theory method was used. Interviews with 21 participants and 30 hours of observation were conducted in hospitals in Iran during 2005. Constant comparative analysis was used to analyse the data.

Findings.  Two main categories, ‘the meaning of evidence‐based nursing’, and ‘factors affecting it’, emerged from the data. From participants’ perspectives, evidence‐based nursing was defined as ‘caring for patients based on the nurse's professional knowledge in meeting patients’ needs’. The second category, factors affecting evidence‐based care, had six subcategories: possessing professional knowledge and experience; having time and opportunity; becoming accustomed; self‐confidence; the process of nursing education; and the work environment and its expectations.

Conclusion.  Managers and educators need to be committed to the principles of EBP, provide resources and create a supportive environment for its implementation. Individual nurses also have a responsibility to carry out evidence‐based nursing, and researchers should work with practitioners to generate high quality evidence to support nursing practice.
Dietary acculturation and diet quality of hypertensive Korean Americans
Authors: Kim Mi Ja , Lee Suk Jeong , Ahn Yang‐Heui , Bowen Phyllis , Lee Hyeonkyeong
Published: May 2007

Title.  Dietary acculturation and diet quality of hypertensive Korean Americans

Aim.  This paper is a report of a study to describe the dietary acculturation of hypertensive and normotensive Korean Americans and native Koreans by comparing dietary pattern and diet quality.

Background.  Dietary acculturation is a major factor that influences the risks for cardiovascular disease in immigrants. Nurses play a key role in educating immigrants about dietary acculturation. Limited studies have examined dietary acculturation of Korean immigrants with hypertension.

Method.  A descriptive study of hypertensive and normotensive Korean Americans and native Koreans (n = 398) was conducted in 2003–04, using the 24‐hour dietary recall method. Dietary pattern was measured by consumption frequency of Korean, American and common food, and eating outside the home. Diet quality was measured by the revised version of the Diet Quality Index.

Findings.  Korean Americans showed greater consumption of American food, common food and fast food, and ate away from home more often than native Koreans. Overall Diet Quality Index scores were not statistically significantly different between the two groups after matching. Compared with native Koreans, Korean Americans consumed lower amounts of sodium, potassium, vegetables and fruits, and energy from carbohydrates. Hypertensive Korean Americans consumed fewer vegetables and fruits, and less sodium and potassium than hypertensive native Koreans. No statistically significant differences were found between hypertensive and normotensive Korean Americans in dietary acculturation.

Conclusion.  Dietary acculturation of immigrants is a common phenomenon regardless of the country from which they immigrate. Healthcare professionals should consider the advantages and disadvantages of dietary acculturation in health promotion for immigrants.
Phylogeographic patterns of trans‐Amazonian vicariants and Amazonian biogeography: the Neotropical rattlesnake (Crotalus durissus complex) as an example
Authors: Adrian Quijada‐Mascareñas J. , Ferguson Julia E. , Pook Catharine E. , Salomão Maria Da Graça , Thorpe Roger S. , Wüster Wolfgang
Published: May 2007

Aim  To investigate the phylogeography and execute a historical‐demographic analysis of the Neotropical rattlesnake, Crotalus durissus, thereby testing the hypothesis of a Pleistocene central Amazon corridor of dry forest or savanna that partitioned the Amazonian rain forest into western and eastern portions.

Location  South America.

Methods  Using sequences of three mitochondrial genes, we estimated the phylogeography, gene and nucleotide diversity across the South American range of C. durissus. Tree topology tests were used to test alternative biogeographical hypotheses, and tests of population genetic structure and statistical parsimony networks and nested clade phylogeographic analysis (NCPA) were used to infer connectivity and historical population processes on both sides of the Amazon basin.

Results  Tree topology tests rejected the hypothesis of a coastal dispersal in favour of a central corridor scenario. Gene diversity was similar on both sides of the Amazon basin. Nucleotide diversity indicated that the populations from north of the Amazon basin represented ancestral populations. Analysis of molecular variance (amova) showed that intra‐population molecular variation was greater than between regions. Historical‐demographic statistics showed significant population expansion south of the Amazon, and little differentiation in the north, indicating moderate past gene flow between north and south of the Amazon. The parsimony network connected clades from the Roraima and Guyana populations with Mato Grosso, suggesting an Amazonian central corridor, and NCPA supported allopatric fragmentation between north and south of the Amazon.

Main conclusions  The distribution of C. durissus on both sides of the Amazon basin is evidence of changes in the distribution of rain forest vegetation during the Pleistocene. Our results suggest a formerly continuous distribution of this rattlesnake along a central Amazonian corridor during the middle Pleistocene. Allopatric fragmentation inferred from NCPA is consistent with vicariance resulting from a subsequent closure of this habitat corridor. This study emphasizes the potential of trans‐Amazonian open formation species to inform the debate on the past distribution of rain forests in the Amazon Basin.
The assessment of criterion audit cycles by external peer review – when is an audit not an audit?
Authors: Bowie Paul , Cooke Sarah , Lo Penny , McKay John , Lough Murray
Published: May 2007

Introduction  Clinical audit has failed to fully deliver the rewards initially envisaged. Contributory factors include: an ill‐defined approach to audit; the assumption that health care professionals can intuitively apply audit methods; and the lack of a system to ‘quality assure’ the process. A method of criterion audit was defined and developed in conjunction with an instrument to facilitate trained General Practitioner (GP) assessors in the review of colleagues’ audit projects. Given the potential for improving audit practice, this study aimed to define the methodological factors that contributed to ‘unsatisfactory’ audits as judged by peer assessors.

Methods  West of Scotland GPs voluntarily submitted a criterion audit in a standard format for review by two trained colleagues using an assessment instrument. Audits judged unsatisfactory and associated educational feedback were subjected to content analysis.

Results  Between 1999 and 2004, 336 audits were submitted, of which 132 (39%) were judged to be unsatisfactory. Of these, 118 audits (89%) had a methodological issue identified in the initial project design (e.g. defining criteria) that effectively invalidated the audit. 119 projects (90%) were also judged to have at least one deficiency in the data analysis or change management stages of the audit (e.g. implementing inadequate change).

Conclusion  A range of audit method issues was found. The proportion of unsatisfactory audits may point to a larger problem beyond this sample, which may have implications for health care quality. If audit practise is to be consistent and rigorous, consideration should be given to assessing the standard of this activity.
Effects of a behaviour independent financial incentive on prescribing behaviour of general practitioners
Authors: Martens Jody D. , Werkhoven Mirjam J. , Severens Johan L. , Winkens Ron A. G.
Published: May 2007

Rationale and objectives  It is difficult to keep control over prescribing behaviour in general practice. The purpose of this study was to assess the initial effects of a behaviour independent financial incentive on the volume of drug prescribing of general practitioners (GPs).

Design  2‐Year Controlled Before After study with an intervention region and a concurrent control region.

Setting and participants  GPs in two regions in the Netherlands (n = 119 and n = 118).

Intervention  A financial incentive for prescribing according to local guidelines on specific drugs or drug categories. The financial incentive consisted of a non‐recurrent, behaviour‐independent allowance.

Main outcome measure  Change in the number of prescriptions for 10 targeted drugs or drug groups.

Results  Significant changes were seen only in three types of antibiotics and in recommended gastric medicines. In almost all cases, effects were temporary.

Conclusion  Behaviour independent financial incentives can be a help in changing prescription behaviour of GPs, but effects are small‐scale and temporary.
New models for old questions: generalized linear models for cost prediction
Authors: Moran John L. , Solomon Patricia J. , Peisach Aaron R. , Martin Jeffrey
Published: May 2007

Background Generalized linear models (GLMs) have recently been introduced into cost data analysis. GLMs, transformations of the linear regression model, are characterized by a particular response distribution from one of the exponential family of distributions and monotonic link function which relates the response mean to a scale on which additive model effects operate.

Objectives This study compared GLMs and ordinary least squares regression (OLS) in predicting individual patient costs in adult intensive care units (ICUs) and sought to define the utility of the inverse Gaussian distribution family within GLMs.

Methods A prospective ‘ground‐up’ utilization costing study was performed in three adult university associated ICUs, enrolling consecutive ICU admissions over a 6‐month period in 1991. ICU utilization, patient demographic and ICU admission day data were recorded by dedicated data collectors. Model performance was assessed by prediction error [mean absolute error (MAE), root mean squared error (RMSE)] and residual analysis.

Results The cohort, 1098 patients surviving ICU, was of mean (SD) age 56 (19.5) years and 41% female. Patient costs per ICU episode (1991 A$) were A$6311 (9689), with range A$106 to A$95602. Prediction error for mean costs was minimal (MAE 4780; RMSE 8965) with OLS using heteroscedastic retransformation of log costs and GLM with Gaussian family and log link (MAE 4798; RMSE 8907). Residual analysis suggested optimal overall performance for the above two models and a GLM with inverse Gaussian family and log link.

Conclusions Traditional cost models of OLS with (log) cost transformation may be supplemented by appropriately specified GLM which more closely model the error structure.
Cetirizine in horses: pharmacokinetics and effect of ivermectin pretreatment
Authors: OLSÉN L. , INGVAST‐LARSSON C. , BONDESSON U. , BROSTRÖM H. , TJÄLVE H. , LARSSON P.
Published: May 2007

The pharmacokinetics of the histamine H1‐antagonist cetirizine and the effects of pretreatment with the antiparasitic macrocyclic lactone ivermectin on the pharmacokinetics of cetirizine were studied in horses. After oral administration of cetirizine at 0.2 mg/kg bw, the mean terminal half‐life was 3.4 h (range 2.9–3.7 h) and the maximal plasma concentration 132 ng/mL (101–196 ng/mL). The time to reach maximal plasma concentration was 0.7 h (0.5–0.8 h). Ivermectin (0.2 mg/kg bw) given orally 1.5 h before cetirizine did not affect its pharmacokinetics. However, ivermectin pretreatment 12 h before cetirizine increased the area under the plasma concentration–time curve by 60%. The maximal plasma concentration, terminal half‐life and mean residence time also increased significantly following the 12 h pretreatment. Ivermectin is an inhibitor of P‐glycoprotein, which is a major drug efflux transporter in cellular membranes at various sites. The elevated plasma levels of cetirizine following the pretreatment with ivermectin may mainly be due to decreased renal secretion, related to inhibition of the P‐glycoprotein in the proximal tubular cells of the kidney. The pharmacokinetic properties of cetirizine have characteristics which are suitable for an antihistamine, and this substance may be a useful drug in horses.
Clinical signs and etiology of adverse reactions to procaine benzylpenicillin and sodium/potassium benzylpenicillin in horses
Authors: OLSÉN L. , INGVAST‐LARSSON C. , BROSTRÖM H. , LARSSON P. , TJÄLVE H.
Published: May 2007

Case reports of 59 horses reacting adversely to procaine benzylpenicillin or to sodium or potassium benzylpenicillin in Sweden in 2003–2005 were obtained through contacts with horse‐owners. For the assessment of the reports, various parameters were evaluated, such as the times to the reactions, information on previous penicillin treatment, the clinical signs and the actions taken in the reacting horses. Among the reports, two horses had received sodium or potassium benzylpenicillin intravenously, whereas the remaining 57 horses had been treated with procaine benzylpenicillin intramuscularly. Allergy may underlie the adverse reactions in the horses given sodium and potassium benzylpenicillin, and in a few of the horses given procaine benzylpenicillin. However, in most horses in the latter group, the clinical signs may be due to the toxic effects of procaine. In these horses, the dominating clinical signs were locomotor and behavioral changes. Some risk factors may enhance the probability that horses react to procaine. One is repeated injections, which increase the likelihood of intravascular administration and also may increase the sensitivity to procaine due to neuronal sensitization (kindling). Procaine is rapidly hydrolyzed by plasma esterases to nontoxic metabolites. When high amounts of procaine enter the circulation, the hydrolyzing capacity may be exceeded and toxicity occurs. Analyses of plasma esterases from reacting horses showed lower activity than in nonreacting control horses. Low esterase activity may increase the possibility of procaine toxicity and constitute another risk factor.
Cryoglobulinaemia associated with hepatitis C virus: influence of HCV genotypes, HCV‐RNA viraemia and HIV coinfection
Authors: Ramos‐Casals M. , Forns X. , Brito‐Zerón P. , Vargas A. , Ruiz M. , Laguno M. , Yagüe J. , Mª Sánchez‐Tapias J. , Mª Gatell J. , Font J.
Published: May 2007

summary.  To determine whether the clinical and immunological expression of patients with cryoglobulinaemia associated with chronic hepatitis C virus (HCV) infection varied according to HCV‐RNA load, HCV genotype or human immunodeficiency virus (HIV) coinfection. We studied 340 HCV patients (188 women and 152 men, with a mean age of 49 years) consecutively diagnosed with cryoglobulinaemia between 1993 and 2003 in our hospital. HCV infection was confirmed by serum HCV‐RNA determination in all patients. Two hundred and forty‐eight (73%) patients had asymptomatic cryoglobulinaemia and 92 (27%) presented cryoglobulinaemic symptoms. Patients with genotype 1 had a higher mean age at diagnosis of cryoglobulinaemia (48.2 vs 40.2 yrs, P < 0.001) and a higher prevalence of cryoglobulinaemic symptoms (25%vs 10%, P = 0.02), especially of vasculitic features (19%vs 5%, P = 0.014). In comparison with monoinfected HCV patients, those with HIV coinfection had a lower mean age at diagnosis of cryoglobulinaemia (40.4 vs 52.8 years, P < 0.001), a lower prevalence of cryoglobulinaemic symptoms (15%vs 34%, P < 0.001), vasculitis (10%vs 28%, P < 0.001), associated systemic autoimmune disease (3%vs 14%, P = 0.001), rheumatoid factor (30%vs 70%, P = 0.001) and hypocomplementaemia (50%vs 78%, P = 0.01). In HCV–HIV patients, a high viral load was associated with a high frequency of symptomatic cryoglobulinaemia, especially in patients with a high viral load of the two viruses (50%vs 7%, P = 0.001) A higher frequency of cryoglobulinaemic symptoms (especially vasculitis) was found in patients with HCV monoinfection and in those carrying HCV genotype 1. In contrast, patients with HIV coinfection presented a threefold lower prevalence of vasculitis. Associated HIV infection significantly attenuated the clinical and immunological expression of cryoglobulinaemia, except in coinfected patients with high viral loads for the two viruses.
Multiple paternity in a natural population of a wild tobacco fly, Bactrocera cacuminata (Diptera: Tephritidae), assessed by microsatellite DNA markers
Authors: SONG SIMON D. , DREW RICHARD A. I. , HUGHES JANE M.
Published: May 2007

Mating frequency has important implications for patterns of sexual selection and sexual conflict and hence for issues such as speciation and the maintenance of genetic diversity. Knowledge of natural mating patterns can also lead to more effective control of pest tephritid species, in which suppression programmes, such as the sterile insect technique (SIT) are employed. Multiple mating by females may compromise the success of SIT. We investigated the level of polyandry and sperm utilization in a Brisbane field population of the tropical fruit fly, Bactrocera cacuminata (Hering), using seven polymorphic microsatellite loci. The offspring of 22 wild‐caught gravid females were genotyped to determine the number of males siring each brood and paternity skew, using the programs gerud and scare. Our data showed that 22.7% of females produced offspring sired by at least two males. The mean number of mates per female was 1.72. Paternal contributions of double‐sired broods were skewed with the most successful male having sired between 76.9% and 87.5% of the offspring. These results have implications for SIT, because the level of remating we have identified would indicate that wild females could mate with one or more resident fertile males.
Specific interactions of three proliferating cell nuclear antigens with replication‐related proteins in Aeropyrum pernix
Authors: Imamura Kaori , Fukunaga Kenzo , Kawarabayasi Yutaka , Ishino Yoshizumi
Published: May 2007

Proliferating cell nuclear antigen (PCNA) is a well‐known multifunctional protein involved in eukaryotic and archaeal DNA transactions. The homotrimeric PCNA ring encircles double‐stranded DNA within its central hole and tethers many proteins on DNA. Plural genes encoding PCNA‐like proteins have been found in the genome sequence of crenarchaeal organisms. We describe here the biochemical properties of the three PCNAs, PCNA1, PCNA2 and PCNA3, from the hyperthermophilic archaeon, Aeropyrum pernix. PCNA2 can form a trimeric structure by itself, and it also forms heterotrimeric structures with PCNA1 and PCNA3. However, neither PCNA1 nor PCNA3 can form homotrimers. The DNA synthesis activity of DNA polymerase I and II, the endonuclease activity of FEN1, and the nick‐sealing activity of DNA ligase were stimulated by the complex of PCNA2 and 3 or PCNA1, 2 and 3. These results suggest that the heterotrimeric PCNA at least including PCNA2 and 3 function as the clamp in the replisome. However, PCNA2 is the most abundant in the cells throughout the growth stages among the three PCNAs, and therefore, PCNA2 may perform multitasks by changing complex composition.
A subset of GAF domains are evolutionarily conserved sodium sensors
Authors: Cann Martin
Published: May 2007

Most organisms maintain a transmembrane sodium gradient for cell function. Despite the importance of Na+ in physiology, no directly Na+‐responsive signalling molecules are known. The CyaB1 and CyaB2 adenylyl cyclases of the cyanobacterium Anabaena PCC 7120 are inhibited by Na+. A D360A mutation in the GAF‐B domain of CyaB1 ablated cAMP‐mediated autoregulation and Na+ inhibition. Na+ bound the isolated GAF domains of CyaB2. cAMP blocked Na+ binding to GAF domains but Na+ had no effect on cAMP binding. Na+ altered GAF domain structure indicating a mechanism of inhibition independent of cAMP binding. ΔcyaB1 and ΔcyaB2 mutant strains did not grow below 0.6 mM Na+ and ΔcyaB1 cells possessed defects in Na+/H+ antiporter function. Replacement of the CyaB1 GAF domains with those of rat phosphodiesterase type 2 revealed that Na+ inhibition has been conserved since the eukaryotic/bacterial divergence. CyaB1 and CyaB2 are the first identified directly Na+‐responsive signalling molecules that function in sodium homeostasis and we propose a subset of GAF domains underpin an evolutionarily conserved Na+ signalling mechanism.
Growth phenotypes of Pseudomonas aeruginosa lasR mutants adapted to the airways of cystic fibrosis patients
Authors: D'Argenio David A. , Wu Manhong , Hoffman Lucas R. , Kulasekara Hemantha D. , Déziel Eric , Smith Eric E. , Nguyen Hai , Ernst Robert K. , Larson Freeman Theodore J. , Spencer David H. , Brittnacher Mitchell , Hayden Hillary S. , Selgrade Sara , Klausen Mikkel , Goodlett David R. , Burns Jane L. , Ramsey Bonnie W. , Miller Samuel I.
Published: May 2007

The opportunistic pathogen Pseudomonas aeruginosa undergoes genetic change during chronic airway infection of cystic fibrosis (CF) patients. One common change is a mutation inactivating lasR, which encodes a transcriptional regulator that responds to a homoserine lactone signal to activate expression of acute virulence factors. Colonies of lasR mutants visibly accumulated the iridescent intercellular signal 4‐hydroxy‐2‐heptylquinoline. Using this colony phenotype, we identified P. aeruginosa lasR mutants that emerged in the airway of a CF patient early during chronic infection, and during growth in the laboratory on a rich medium. The lasR loss‐of‐function mutations in these strains conferred a growth advantage with particular carbon and nitrogen sources, including amino acids, in part due to increased expression of the catabolic pathway regulator CbrB. This growth phenotype could contribute to selection of lasR mutants both on rich medium and within the CF airway, supporting a key role for bacterial metabolic adaptation during chronic infection. Inactivation of lasR also resulted in increased β‐lactamase activity that increased tolerance to ceftazidime, a widely used β‐lactam antibiotic. Loss of LasR function may represent a marker of an early stage in chronic infection of the CF airway with clinical implications for antibiotic resistance and disease progression.
The intramembrane active site of GlpG, an E. coli rhomboid protease, is accessible to water and hydrolyses an extramembrane peptide bond of substrates
Authors: Maegawa Saki , Koide Kayo , Ito Koreaki , Akiyama Yoshinori
Published: May 2007

Escherichia coli GlpG is an orthologue of the rhomboid proteases that catalyse intramembrane proteolysis of specific membrane proteins. We previously showed that it can cleave a type I model membrane protein, Bla‐LY2‐MBP, having the second transmembrane region of lactose permease (LY2) in vivo and in vitro at the predicted periplasm–membrane boundary region of LY2. Here we investigated the environment of the active site regions of GlpG in the membrane‐integrated state by examining the modifiability of Cys residues introduced into the regions around the catalytic residues with membrane‐permeable and ‐impermeable alkylating reagents. The results indicate that the enzyme active site is fully open to the external aqueous phase. GlpG also cleaved a similar fusion protein, Bla‐GknTM‐MBP, having the transmembrane region of Gurken (GknTM), a physiological substrate of Drosophila rhomboids. Engineered Cys residues in the cleavage site regions of the LY2 and GknTM sequences were efficiently modified with a membrane‐impermeable alkylating reagent, showing that these regions are exposed to the periplasm. These results suggest that GlpG cleaves an extramembrane region of substrates, unlike the currently prevailing view that this class of membrane proteases acts against a membrane‐embedded polypeptide segment after its lateral entrance into the enzyme's active site.
Regulation of interstitial cells of Cajal in the mouse gastric body by neuronal nitric oxide
Authors: Choi K. M. , Gibbons S. J. , Roeder J. L. , Lurken M. S. , Zhu J. , Wouters M. M. , Miller S. M. , Szurszewski J. H. , Farrugia G.
Published: May 2007

Abstract  The factors underlying the survival and maintenance of interstitial cells of Cajal (ICC) are not well understood. Loss of ICC is often associated with loss of neuronal nitric oxide synthase (nNOS) in humans, suggesting a possible link. The aim of this study was to determine the effect of neuronal NO on ICC in the mouse gastric body. The volumes of ICC were determined in nNOS−/− and control mice in the gastric body and in organotypic cultures using immunohistochemistry, laser scanning confocal microscopy and three‐dimensional reconstruction. ICC numbers were determined in primary cell cultures after treatment with an NO donor or an NOS inhibitor. The volumes of myenteric c‐Kit‐immunoreactive networks of ICC from nNOS−/− mice were significantly reduced compared with control mice. No significant differences in the volumes of c‐Kit‐positive ICC were observed in the longitudinal muscle layers. ICC volumes were either decreased or unaltered in the circular muscle layer after normalization for the volume of circular smooth muscle. The number of ICC was increased after incubation with S‐nitroso‐N‐acetylpenicillamine and decreased by N(G)‐nitro‐l‐arginine. Neuronally derived NO modulates ICC numbers and network volume in the mouse gastric body. NO appears to be a survival factor for ICC.
Impact of 5‐HT3 receptor blockade on colonic haemodynamic responses to ischaemia and reperfusion in the rat
Authors: Grundy D. , Mclean P. , Stead R.
Published: May 2007

Abstract  5‐HT3 receptor antagonists are clinically available for treating patients with irritable bowel syndrome (IBS) but their use is restricted because of a link with some episodes of ischaemic colitis. However, the role of 5‐HT3 receptors in regulating colonic blood flow has not been systematically investigated. Thus, we examined acute and chronic treatment with alosetron, a potent and selective antagonist of the 5‐HT3 receptor, on baseline colonic blood flow and haemodynamic responses during occlusion and reactive hyperaemia in the pentobarbitone‐anaesthetized rat. Colonic haemodynamics were assessed using ultrasonic recordings of superior mesenteric blood flow (MBF) and laser Doppler recordings of colonic vascular perfusion (VP). Blood pressure (BP) was also monitored and in some experiments tissue oxygen was detected polarographically. Alosetron (10, 30, 100 μg kg−1, i.v.) had no effect on baseline haemodynamics nor responses to nitric oxide synthase inhibition with Nω‐nitro‐l‐arginine methyl ester (l‐NAME) (16 mg kg−1). Arterial occlusion (5 min) reduced MBF (−98.6 ± 0.6%) and VP (−70.7 ± 5.4%) followed by a post‐occlusion reactive hyperaemia (MBF = +94.5 ± 19.1%; VP = +60.0 ± 22.3%) the magnitude of which was unchanged following acute (30 μg kg−1) or chronic alosetron administration (0.5 mg kg−1 twice daily, 5 days). Alosetron did not significantly alter baseline colonic blood flow in the anaesthetized rat; nor did it interfere with vascular control mechanisms activated during occlusion and reactive hyperaemia.
White matter lesions in an unselected cohort of the elderly: astrocytic, microglial and oligodendrocyte precursor cell responses
Authors: Simpson J. E. , Fernando M. S. , Clark L. , Ince P. G. , Matthews F. , Forster G. , O'Brien J. T. , Barber R. , Kalaria R. N. , Brayne C. , Shaw P. J. , Lewis C. E. , Wharton S. B. ,   MRC Cognitive Function and Ageing Neuropathology Study Group
Published: May 2007

Hyperintense lesions are frequently identified in T2‐weighted magnetic resonance images (MRI) in the ageing brain. The pathological correlate and pathogenesis of white matter lesions (WML) remain unclear, and it is uncertain whether pathology and pathogenesis differ in periventricular lesions (PVL) compared with deep subcortical lesions (DSCL). Therefore we characterized astrocytic, microglial and oligodendrocyte responses in PVL and DSCL and compared them with control white matter using immunohistochemistry. Both PVL and DSCL were associated with severe myelin loss and increased microglia (P = 0.069 and P < 0.001), compared with nonlesional aged brain. Clasmatodendritic astroglia, immunoreactive for the serum protein fibrinogen, were present in 67% of PVL examined and 42% of DSCL. Compared with control and DSCL cases, more MAP‐2 +13 positive remyelinating oligodendrocytes (P = 0.003 and P = 0.035) and platelet‐derived growth factor α receptor positive reactive astrocytes (P < 0.001) were present in the perilesional white matter of PVL. In addition to a role for hypoperfusion, our data suggest that dysfunction of the blood–brain barrier may also contribute to the pathogenesis of a proportion of cerebral WML associated with ageing, and that attempts at remyelination are only associated with PVL and not DSCL.
Increased Asymmetric Dimethylarginine Concentrations in Stimulated Peripheral Blood Mononuclear Cells
Authors: Schroecksnadel K. , Weiss G. , Stanger O. , Teerlink T. , Fuchs D.
Published: May 2007

Elevated concentrations of total homocysteine as well as of asymmetric dimethylarginine (ADMA) in the blood have been reported to reflect an increased cardiovascular risk. ADMA is formed by endothelial cells and is an endogenous inhibitor of NO synthase. Earlier we have found that human peripheral blood mononuclear cells (PBMC) produce homocysteine upon stimulation with mitogens concanavalin A, phytohaemagglutinin and pokeweed mitogen. In this study, the ability of PBMC to form ADMA and symmetric dimethylarginine (SDMA) was determined. Effects were compared with levels of cysteine, homocysteine and arginine in cultures. Increased concentrations of ADMA and SDMA were found in mitogen‐stimulated compared with unstimulated PBMC. Arginine and cysteine concentrations did not differ between stimulated and unstimulated PBMC. There existed significant associations between concentrations of homocysteine and ADMA (Spearman rank correlation (rs) = 0.575) as well as SDMA (rs = 0.436, both P < 0.001). Treatment of stimulated PBMC with the anti‐inflammatory compounds salicylic acid (5 mm) and atorvastatin (25 μm) decreased the rate of ADMA and SDMA formation. Results of these in vitro studies show that ADMA and SDMA formation coincides with homocysteine production in human PBMC. Activated PBMC not only release Th1‐type cytokine γ‐interferon, which is the most important inducer of nitric oxide synthase, but also ADMA, a natural inhibitor of the enzyme.
Pharmacokinetics and tolerability of intravenous busulfan in hematopoietic stem cell transplantation
Authors: Cho Yo‐Han , Lim Hyun‐Ae , Lee Mark Hong , Kim Inho , Lee Jong Seok , Park Seong yang , Kim Byoung Kook , Yoon Sung‐Soo
Published: May 2007

Abstract:  Intravenous (IV) busulfan has been developed to overcome variable absorption of oral busulfan and tested in several trials. We tested its pharmacological properties and tolerability in 16 Korean stem cell transplantation (SCT) patients. IV busulfan was administered at 0.8 mg/kg every six h for a total of 16 doses (days −7 to −4), which was followed by cyclophosphamide administration at 60 mg/kg every 24 h for two d (days −3 and −2). The median AUCinf values (at the first dose) and AUCss (at the steady state) were 1060.4 μM·min (range: 511.1–1812.7) and 1092.5 μM·min (range: 539.7–1560.8) respectively. All patients had an AUCinf of <1500 μM·min at the first dose, and 13 of the 16 (81.3%) maintained AUCss levels between 800 and 1500 μM·min. Thirteen of 16 patients showed successful engraftments but four patients (25%) developed hepatic VOD (two of which were fatal), three of whom had advanced disease at the time of SCT. Overall, pharmacokinetics of IV busulfan in our SCT patients appeared comparable with those observed in other study. However, hepatic VOD was a major morbidity in patients with advanced disease.
Cardiac transplantation in a 14‐yr‐old patient with mitochondrial encephalomyopathy
Authors: Schmauss D. , Sodian R. , Klopstock T. , Deutsch M. A. , Kaczmarek I. , Roemer U. , Reichart B. , Daebritz S. H.
Published: May 2007

Abstract:  We report a rare case of a successful cardiac transplantation in a patient suffering from cardiomyopathy and complex mitochondrial disease. The patient presented with severe heart failure and malignant ventricular arrhythmias requiring implantation of a defibrillator and advanced medical treatment. The patient was listed for urgent heart transplantation and received a donor heart after 36 days. One yr post‐operatively, the patient has completely recovered.
Social support, coping, and psychological distress in mothers and fathers of pediatric transplant candidates: A pilot study
Authors: Simons Laura , Ingerski Lisa M. , Janicke David M.
Published: May 2007

Abstract:  Both parents and children report significant psychological difficulties and family disruption prior to transplantation; however, there have been fewer studies examining predictors of distress in both mothers and fathers and across multiple transplant groups. Thirty‐four mothers and 22 fathers participated in this pilot study. Parents completed measures during a routine tertiary pretransplant psychological evaluation. Paired sample t‐test results indicated that mothers and fathers differed significantly on specific coping strategies employed, with fathers less likely to use engagement strategies than mothers. Correlation analyses demonstrated strong associations between engagement coping strategies and less psychological distress and the reverse with disengagement coping strategies for both mothers and fathers. Social support was associated with less psychological distress for mothers, but was unrelated to distress for fathers. Using regression analyses, for mothers, lack of social support, and disengagement coping predicted poor psychological outcomes. Taken together, these results suggest that assessing specific coping strategies employed by both mothers and fathers is an essential component of the pretransplant evaluation process. This study delineates areas for intervention that impact adjustment in parents of pediatric transplant candidates.
Expression of PIP1 and PIP2 aquaporins is enhanced in olive dwarf genotypes and is related to root and leaf hydraulic conductance
Authors: Lovisolo Claudio , Secchi Francesca , Nardini Andrea , Salleo Sebastiano , Buffa Rosalia , Schubert Andrea
Published: May 2007

The expression of OePIP1.1 and OePIP2.1 aquaporins in root, stem and leaf was higher in Olea europaea L. (olive) plants carrying a dwarfing (D) clone as rootstock, than in plants carrying a vigorous (M) clone as rootstock. The highest difference of expression between plants with D and M rootstocks was detected in the root and for the PIP2 gene, the transcripts of which show a high water channel activity in oocytes.

 Compared with plants with M rootstock, plants with D rootstock showed reduced root and canopy biomass and reduced hydraulic conductance of the bulk root system (Kroot). Hydraulic conductance of D roots was higher than that of M roots when Kroot was scaled by root DW, in agreement with a higher expression of PIP genes. Leaf hydraulic conductance scaled by unit leaf surface area was almost twice as high in leaves from D plants compared with that in leaves from M plants.

 Modification of root growth imposed by grafting M onto D and D onto M slightly changed expression levels of root OePIP1.1 gene, the transcripts of which show almost null water channel activity in oocytes, suggesting a role less evident for OePIP1.1 in root hydraulic reequilibration.

 The role of PIP aquaporin gene expression in partially compensating reductions of plant hydraulic conductance is discussed.
Evaluation of the stress‐inducible production of proline in transgenic sugarcane (Saccharum spp.): osmotic adjustment, chlorophyll fluorescence and oxidative stress
Authors: Molinari Hugo Bruno Correa , Marur Celso Jamil , Daros Edelclaiton , De Campos Marília Kaphan Freitas , De Carvalho Jane Fiuza Rodrigues Portela , Filho João Carlos Bespalhok , Pereira Luiz Filipe Protasio , Vieira Luiz Gonzaga Esteves
Published: May 2007

Proline accumulates in a variety of plant species in response to stresses such as drought, salinity and extreme temperatures. Although its role in plant osmotolerance remains controversial, proline is thought to contribute to osmotic adjustment, detoxification of reactive oxygen species and protection of membrane integrity. In the present study, we evaluated the effects of stress‐inducible proline production on osmotic adjustment, chlorophyll fluorescence and oxidative stress protection in transgenic sugarcane transformed with a heterologous P5CS gene. In well‐watered conditions, free proline, malondialdehyde (MDA) levels, Fv/Fm ratios and chlorophyll contents (Chls) in transgenic sugarcane were not statistically different from non‐transformed control plants. After 9 days without irrigation, proline content in transgenic events was on the average 2.5‐fold higher than in controls. However, no osmotic adjustment was observed in plants overproducing proline during the water‐deficit period. The photochemical efficiency of PSII observed was higher (65%) in the transgenic events at the end of the water‐deficit experiment. The effects of proline on lipid peroxidation as MDA levels and on the decline of Chl in paraquat‐treated leaf discs along the drought period suggest that proline protected the plants against the oxidative stress caused by the water deficit. The overall capacity of transgenic plants to tolerate water‐deficit stress could be assessed by the significantly higher biomass yields 12 days after withholding water. These results suggest that stress‐inducible proline accumulation in transgenic sugarcane plants under water‐deficit stress acts as a component of antioxidative defense system rather than as an osmotic adjustment mediator.
Increase in activity, glycosylation and expression of cytokinin oxidase/dehydrogenase during the senescence of barley leaf segments in the dark
Authors: Conrad Klaus , Motyka Václav , Schlüter Torsten
Published: May 2007

The aim of the study was to elucidate relations between senescence and cytokinin oxidase/dehydrogenase (CKX, EC 1.4.3.18/1.5.99.12). Segments derived from first foliage leaves of Hordeum vulgare L. cv. Alexis were put with their bases into water and kept in darkness. Their senescence was characterized, e.g. by a 60% decline in chlorophyll within 5 days. During this time, the in vitro activity of CKX increased fast and markedly, e.g. 14‐fold. Application of 10−4M kinetin (Kin), which slightly retarded the loss of chlorophyll, multiplied the enhancement of CKX activity strongly. Both in the presence and in the absence of Kin, the proportion of glycosylated to non‐glycosylated CKX increased during senescence. By hybridization with an antisense RNA probe derived from a fragment of the CKX gene Zmckx1 of maize, an increase of the corresponding transcript of the barley gene Hvckx1 in segments incubated without Kin was shown. The content of base and riboside cytokinins slowly declined in such segments, which argues against triggering but for facilitating senescence processes by CKX.