bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on differently pretreated non-woven cotton substrates
Authors: Slopek Ryan , Condon Brian , Sawhney Paul , Reynolds Michael , Allen Chuck
Published: May 2011

The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached non-woven cotton fabrics was investigated at varying surfactant concentrations using ultraviolet-visible spectroscopy. Results show greige cotton non-wovens adsorb roughly three times the ADBAC in aqueous solution than bleached cotton and 1.5 times more than scoured cotton non-wovens. At a constant ADBAC concentration of 0.625 g/l, the rate of surfactant adsorption approached equilibrium after 35 minutes in all fabrics studied. Increasing surfactant concentration increased the total mass of ADBAC exhausted onto the cotton fabrics at equilibrium. Adsorption of ADBAC on cotton fabrics can be attributed to bulk entrapment, dispersion forces, and hydrophobic and electrostatic interactions. Polyester fiber was blended with greige and bleached cotton fibers to further elucidate the adsorption of ADBAC. A linear decrease in the amount of surfactant exhausted was observed as the amount of polyester added to the blend was increased. This indicates that the adsorption of ADBAC on cotton fabrics is primarily an effect of surface interactions of the cotton fiber with the surfactant molecules rather than absorption via bulk entrapment. The results of this research can aid in the development of cotton-based antimicrobial wipes.
Downtime of in-use water pump installations for high-rise residential buildings
Authors: Mui KW , Wong LT , Hui KW
Published: May 2011

This study examines the fresh and flushing water pump installations for high-rise residential buildings in Hong Kong in terms of system availability, mean time to failure, mean time between failures and restoration time. Together with some reliability data published elsewhere, it applies Bayesian analysis to improve our understanding of the downtime characteristics of water pump installations. For three consecutive years (2005–2007), water pump failures in 46 typical high-rise residential buildings were recorded to determine the component failure rates. In order to study the failure patterns, Monte Carlo simulations were performed for the operations of 100 parallel pump sets over a period of 10 years. The mean time to failure, total downtime, failure counts and system availability estimated for the fresh water pump installations were 1.24 years, 8990 h, 709 and 90% while those estimated for the flushing seawater pump installations were 0.46 years, 4049 h, 2081 and 78%, respectively. The results are useful in the calculation of water supply availability for high-rise residential buildings while keeping the balance between maintenance cost and system reliability. This study also demonstrates a method for reliability modelling of water supply for high-rise residential buildings.

Practical applications: This study demonstrates a method for reliability modelling of building services systems. With the use of Bayesian analysis, example estimates of the mean time to failure, total downtime, failure counts and system availability were determined for the fresh and flushing water pump installations for high-rise residential buildings in Hong Kong.
Spontaneous Thymoma in a Juvenile Cynomolgus Macaque (Macaca fascicularis)
Authors: Schwartz J. A. , Solomon J. A. , Henkelman K. , Leininger J. R. , Iverson W. O.
Published: May 2011

A single, solid, yellow-white thymic mass was found at necropsy of a two-year-old female cynomolgus macaque from a four-week, repeat-dose toxicity and immunogenicity study. Microscopically, the mass was multilobular and well encapsulated, surrounded by a thick connective tissue capsule, and composed of dense sheets of elongate or spindle-shaped cells and large cystic cavities separated by thick connective tissue stroma. Normal thymus was adjacent to the mass, but it was compressed. Within the mass were abundant interspersed Hassall’s corpuscles; individual and small clusters of mature, small lymphocytes; scattered eosinophils; large areas of necrosis; focal mineralization; and cholesterol clefts. An interesting feature was the presence of large multinucleated giant cells, which varied widely in size and nuclear number. Immunohistochemical staining for two lymphocyte markers and two structural proteins confirmed the identity of the neoplastic spindle cells and other cellular components. There was no evidence of vascular invasion or metastasis. Features of the thymoma indicated it was a pre-existing condition and not treatment related.
Central venous catheters may be a potential source of massive air emboli during vascular procedures involving extracorporeal circulation: an experimental study
Authors: Høgetveit J.O. , Saatvedt K. , Norum H. , Kristiansen F. , Elvebakk O. , Dahle G. , Geiran O.R.
Published: May 2011

Central venous catheters are mandatory during every major procedure involving extracorporeal circulation. Air emboli potentially could enter the circulation through this device when negative pressure is applied in the venous cannula. The following experimental study was initiated by a fatal massive air embolus during a vascular procedure involving cardiopulmonary bypass. An experimental setup was established, simulating a real scenario. The experiment was performed with a 40% glycerol/water mixture which exhibits properties and fluid dynamics close to blood. A heart-lung machine provided circulation of the fluid. The flow was adjusted according to the gravitational status. A triple-lumen central venous catheter with one line open to air was lowered into the liquid. The disconnected lumen of the central venous catheter was manipulated so it approached and was located in close proximity to the venous cannula. An air flow of up to 300 ml/min could be obtained from the central venous catheter with a flow in the cardiopulmonary bypass circuit of 2.3 L/min. A linear relationship was observed between flow in the circuit and air flow. Consecutive measurements proved consistent with acceptable results, proving that a disconnected central venous catheter might, under certain circumstances, be a source of massive air emboli during cardiopulmonary bypass.
Transfusions during cardiopulmonary bypass: better when triggered by venous oxygen saturation and oxygen extraction rate
Authors: Ranucci M. , Castelvecchio S. , Ditta A. , Brozzi S. , Boncilli A. , Baryshnikova E. ,   Surgical and Clinical Outcome Research (SCORE) group
Published: May 2011

During cardiopulmonary bypass (CPB), red blood cell transfusions may be required to correct dilutional anemia. The decision-making process for transfusions is usually based on the level of hemoglobin.This study investigates the hypothesis that oxygen-derived variables (mixed venous oxygen saturation, SvO2, and oxygen extraction rate, O2ER) may be more reliable predictors of the efficacy of the transfusion.

Thirty-six patients for 41 transfusion episodes during CPB were retrospectively analyzed. For each patient, oxygen-derived variables, including SvO2 and O2ER, were measured before and after the transfusion. No changes in pump flow were allowed between the two measurements. The efficacy of transfusion was defined as an increase in SvO2 of at least 5%.

We identified 11 transfusion episodes leading to an efficacious SvO 2 increase. Factors associated with the efficacy of the transfusion were a low SvO2 and a high O2ER. No association was found with hemoglobin values, unless for a trend for efficacy of transfusion in patients with very low (<6 g/dL) hemoglobin values. Cut-off values of 68% for SvO2 and 39% for O2ER were predictive for the efficacy of red blood cell transfusions, with a high accuracy (c-statistics 0.856 and 0.848, respectively) and negative and positive predictive values exceeding 82%. In conclusion, SvO2 and O2ER are better than the hemoglobin value for guiding the decision-making process of red blood cell transfusions to correct hemodilutional anemia during CPB.
Tough or Tender
Authors: Donovan Roxanne A.
Published: May 2011

Although intersectional theory and empirical evidence suggest that race impacts how women are perceived, there is a dearth of research on how the dominant culture stereotypes Black women compared to White women. The current study addresses this gap using an intersectional framework to investigate White college students' stereotypes of Black and White women. How these stereotypes fit with stereotypic images found in theoretical/empirical literature was also examined. Analyses of data from 109 White college students revealed that Black women were perceived in ways consistent with the Matriarch/Sapphire stereotypic image (e.g., strong and domineering). This image stands in contrast to current and previous perceptions of (White) women as affective and communal. The impact of the Matriarch/Sapphire image on Black women is likely mixed. Internalizing the strength aspect of the Matriarch/Sapphire could help Black women cope with the negative effects of racism, sexism, and classism. Conversely, being perceived as innately strong and domineering could increase the blame attributed to Black women who are survivors of sexual assault and/or domestic violence, limiting avenues of support and justice available to these women. It could also lead to a minimization of Black women’s mental and physical health problems. Interventions that educate professionals about the Matriarch/Sapphire image could help reduce its negative impact.
Improved interdigital sensors for structural health monitoring of composite retrofit systems
Authors: Nassr Amr A. , El-Dakhakhni Wael W.
Published: May 2011

In this article, an improved sensor performance based on detecting the dielectric variations in composite—concrete interface and linking these variations to bond deterioration is presented. The use of composites in retrofitting concrete structures is becoming a standard technique worldwide. The bond between the composite system and the concrete element surface is essential to ensure achieving the designed performance. However, there is little research on the development of an economic structural health monitoring technique for monitoring bond quality in large structures, such as buildings and bridges. The improved sensing technique utilizes an Interdigital Capacitance Sensor design to increase the signal-to-noise ratio and to detect shallow—depth bond deteriorations. An analytical modeling technique was used to analyze the influence of the different sensor parameters, especially the dependency of the capacitance signals on the sensor geometrical dimensions. Two-dimensional finite element (FE) simulations were also used to assess different related design parameters and to verify the experimental results. A concrete slab retrofitted with composites containing pre-induced air voids to simulate bond deteriorations defects were constructed and inspected in a laboratory setting. Good agreements were found between experimental capacitance signal response parameters and those predicated from the FE simulations of the slab specimen.
Use of and Attitudes Toward Current Care Guidelines Among Primary and Secondary Care Nurses in Finland
Authors: Kuronen Risto , Jallinoja Piia , Patja Kristiina
Published: May 2011

Attitudes toward, familiarity with, and use of clinical guidelines in general and the national Hypertension Guideline were studied. A questionnaire study was conducted before and after an educational program (VALTIT) among primary and secondary care nurses in Päijät-Häme, Finland. The program included centralized training sessions and interactive local workshops. Prior to the program, a majority of nurses had a positive attitude toward guidelines but used guidelines seldom. Primary care nurses were better aware of the Hypertension Guideline than secondary care nurses, but the guideline was poorly used by both groups. At the follow-up, familiarity with the Hypertension Guideline and use of guidelines increased among primary care nurses. In future, primary care nurses will have a more autonomous role in patient care and should participate in clinical guideline development and related research. Our study has shown they are a potential target of such interventions.
Changing the Tune of Academic Writing: Muting Cognitive Entrenchment
Authors: Dane Erik
Published: May 2011

Much academic writing sounds the same—stilted, distant, and overly qualified. The “sound” of academic writing is primarily the result of institutional pressures that lead authors to become cognitively entrenched in their writing style. The author of this article suggests that we not only can but should mute cognitive entrenchment and change the tune of academic writing. The author also suggests three routes for doing so—writing for nonacademic audiences, writing creatively, and reading widely—and addresses possible objections to his appeal.
Safety and quality assurance of chemotherapeutic preparations in a hospital production unit: Acceptance sampling plan and economic impact
Authors: Paci A , Borget I , Mercier L , Azar Y , Desmaris RP , Bourget P
Published: May 2011

Objective: The opportunity to apply a sampling plan was evaluated. Costs were computed by a microcosting study.

Setting: In 2003, a sampling plan was defined to reduce the number of chemotherapy quality controls while preserving the same level of quality. Recent qualitative and quantitative changes led us to define a second sampling plan supplemented by an economic evaluation to determine the cost and cost-savings of quality control.

Methods: The study considers preparation produced during four semesters classified into three groups. The first one includes drugs produced below 200 batches a semester. Group 2, those for which the lot of preparation lots would have been rejected twice among these four semesters. Group 3, those would have been accepted (≥3 ‘acceptable lot’). A single sampling plan by attributes was applied to this group with an acceptance quality level of 1.65% and a lot tolerance percent defective below 5%. A micro-costing study was conducted on quality control, from the sampling to the validation of the results.

Results: Among 39 cytotoxic drugs, 11 were sampled which enabled to avoid a mean of 17,512 control assays per year. Each batch of the 28 non-sampled drugs was however analyzed. Costs were estimated at 2.98€ and 5.25€ for control assays depending of the analytical method. The savings from the application of the sampling plans was 153,207€ in 6 years.

Conclusion: The sampling plan allowed maintaining constancy in number of controls and the level of quality with significant costsavings, despite a substantial increase in drugs to assay and in the number of preparations produced.
Activating Community Health Center Patients in Developing Question-Formulation Skills
Authors: Lu Wei-Hsin , Deen Darwin , Rothstein Dan , Santana Luz , Gold Marthe R.
Published: May 2011

The authors developed and delivered a brief patient activation intervention (PAI) that sought to facilitate physician–patient communication. The intervention was designed to assist low-income, racial/ethnic minority users of community health centers in building skills and confidence asking questions. The PAI takes 8 to 10 minutes to deliver and consists of five steps that can be carried out by individuals with minimal formal medical training. A total of 252 patients waiting to see their physician participated in the intervention and completed the follow-up semistructured interview after their health care visit. The authors describe the intervention and the results of their qualitative evaluation of patient’s responses. Overall, the PAI was valued by patients, appeared to add to patients’ satisfaction with the health care they received, and was feasible to implement in the primary care setting. Furthermore, findings from this study provide indirect insight regarding factors that influence minority patient’s question-asking behavior that include patient’s attitudes, social factors, and patient’s self-efficacy in question formulation.
The combined influence of top and middle management leadership styles on absorptive capacity
Authors: Sun Peter Y.T. , Anderson Marc H.
Published: May 2011

Absorptive capacity is an important organizational capability constituted by exploratory, transformative, and exploitative learning processes. Leadership has been shown to affect such processes, but little is known about how the combined leadership styles of top and middle management influence absorptive capacity. This theory-building, exploratory qualitative case study discusses the need for top and middle management to be ambidextrous and to change their styles to better facilitate the three different learning processes. We found that an exploratory learning process was facilitated when both top and middle management used a transformational style, a transformative learning process was facilitated when top management used a transformational style while middle management used a transactional style, and an exploitative learning process was facilitated when both top and middle management used a transactional style. Furthermore, for each of the three learning processes, the leadership styles of top and middle management operated more effectively when certain attributes of the organizational context were emphasized.
Anxiety and experience-based learning in a professional standards context
Authors: Gilmore Sarah , Anderson Valerie
Published: May 2011

This article contributes an analysis of the use of experiential learning and reflection within a management education context where its use has received less attention: a learning environment dominated by the requirements of a professional body, where successful attainment of the qualification offered by the programme is linked with entry into the profession and to promotion within it. Using a psychoanalytic lens, this study shows the tension occurring between experiential learning methods and the ‘expert knowledge’ requirements of professional bodies. Tension is essential for learning but we argue that the consequences of it are uncertain and that it deserves more attention within the management education domain. We highlight the ways by which anxiety generated by this tension can stimulate meaningful and reflexive outcomes but our findings also indicate that ‘learning inaction’ (Vince, 2008) is also possible, particularly where tutors are unable to provide a sufficient ‘holding’ environment when anxieties arising from experience-based learning and expert knowledge demands become too hard to bear.
An attempt to isolate, and then differentiate, transfer and interference
Authors: Grosjean François
Published: May 2011

Transfer/interference has a long history in bilingualism research with moments of clear interest and moments of disregard. We are currently entering a period of renewed interest. In the first part of this article, it is argued that the only way to isolate transfer/interference from other contact phenomena such as code-switching and borrowing is to put bilingual speakers in a strictly monolingual language mode. In the second part, an attempt is made to differentiate between static and dynamic transfer/interference. It is suggested that we use the term ‘transfer’ for static phenomena which reflect permanent traces of one language (La) on the other (Lb), and that we use the term ‘interference’ for dynamic phenomena which are elements of the other language(s) which slip into the output of the language being spoken or written. According to this view, interferences are linked to processing. A way of differentiating empirically between transfer and interference is described. It is a byproduct of a study conducted at the University of Neuchâtel which was aimed at getting a better understanding of restructuring in an L1, based on the long-term influence of an L2. In the third part of the article, two other studies are described which examined the comprehension of speech containing transfers/interferences.
‘Early days’: Knowledge and use of the Mental Capacity Act 2005 by care home managers and staff
Authors: Manthorpe Jill , Samsi Kritika , Heath Hazel , Charles Nigel
Published: May 2011

The Mental Capacity Act (MCA) was fully implemented in England and Wales in October 2007 and has relevance for the care home sector through its focus on decision-specific assessments of capacity. This article reports on research that forms part of a five year programme exploring evidence-based interventions in dementia and this article draws on part of the research that was designed to identify issues relating to implementation of the Act. Specific research questions for this study pertain to staff abilities to incorporate a new legal framework addressing mental capacity into care of people with dementia. Qualitative interviews with 32 staff in one group of care homes in Southern England demonstrated that, regardless of knowledge of MCA, the daily working ethos of staff appeared to be within the remit of Act. Training could therefore continue to build on these principles. However, considerable variation in understanding of terms and principles of the MCA was found. Few participants were aware of specific legislative points and offered ‘common sense’ explanations for their actions and decision-making. This level of knowledge may not meet regulators’ requirements or the needs of residents.
Psychological trauma and fear for personal safety as a result of behaviours that challenge in dementia: The experiences of healthcare workers
Authors: Scott Ann , Ryan Assumpta , James Ian A. , Mitchell Elizabeth A.
Published: May 2011

Few studies have systematically documented the psychological effects of exposure to aggression on healthcare workers. In 2007 an exploratory study invited 96 nurses and 228 care assistants from nine care homes to complete a questionnaire that incorporated the Impact Events Score — Extended (IES-E). Of the 112 returned (response rate 34.56%), 77 (68.8%) staff had been involved in an incident where they feared for their personal safety and 80 (71.4%) witnessed an incident where they feared for the safety of a colleague. Over the previous year 34% felt ‘very unsafe’ and almost 18% felt ‘terrified’. Violence against care home staff are not isolated incidents and irrespective of length of time working in dementia care staff lack the skills to identify triggers factors or appreciate the role they play in activating aggression. Their reluctance to engage with aggressive residents compromises care. An increasing ageing population combined with prevalence rates for dementia will place greater demands on care homes. Nationally agreed accredited qualifications for care assistants based on knowledge, and skills and attitudes specific to dementia care, may raise the standard of care. Infrastructures to support assaulted staff may reduce feelings of isolation, assist with recruitment and retention problems and provide social support.
Standard of Care for Antiretroviral Therapy Adherence and Retention in Care from the Perspective of Care Providers Attending the 5th International Conference on HIV Treatment Adherence
Authors: Amico K. Rivet
Published: May 2011

Objective: To characterize standard clinical care for antiretroviral therapy (ART) adherence and retention in HIV-care support strategies among care providers attending the 2010 5th International Conference on HIV Treatment Adherence. Methods: A brief survey was included in conference packets, covering adherence monitoring and support strategies and retention in care strategies used in standard clinical care. Results: A total of 51 attendees returned surveys, representing clinical care provided to over 25 000 patients. Common adherence support strategies used included individual/group counseling, case management/systems navigation, and pillbox organizers. Common retention strategies were transportation assistance, reminder calls, and system navigation support. Conclusions: This small sample, likely representative of higher end quality adherence and retention care, suggests that strategies for monitoring/promoting these behaviors are well-recognized as important and diversely addressed. With most respondents feeling that improvements are needed, the potential for collaborative efforts between practice and research communities that emphasize practice-based evidence and better dissemination and implementation of research are needed.
Information by Design: How Employee Perceptions of Organizational Design Relate to Injury Reporting
Authors: Lauver Kristy J. , Quinn Trank Chris , Le Huy
Published: May 2011

Using survey methodology, this study examines employee perceptions of two key organizational design factors (employee empowerment and alignment of safety practices) and their relationship with nonreporting of employee injuries and near misses. Results show employee perceptions of alignment of safety practices are related to decreased levels of unreported near misses and unreported first aid injuries. However, perceptions of employee empowerment generated counterintuitive results, indicating empowerment is associated with increased levels of unreported near misses. Given the importance of reporting safety incidents, including near misses, to improving safety outcomes, the results reveal that organizational designs that empower employees with regard to safety may yield unintended—and undesirable—consequences.
Multiple sclerosis and chronic cerebrospinal venous insufficiency: a critical review
Authors: Awad Amer M. , Marder Ellen , Milo Ron , Stüve Olaf
Published: May 2011

Chronic cerebrospinal venous insufficiency (CCSVI) was recently proposed as a contributing factor in the pathology of multiple sclerosis. This concept has gained remarkable attention, partly because endovascular neurointervention has been suggested as a treatment strategy. This review summarizes available evidence and provides a critical analysis of the published data. Currently, there is inconclusive evidence to support CCSVI as an etiological factor in patients with multiple sclerosis. Endovascular procedures should not be undertaken outside of controlled clinical trials.
In Practice
Authors: Waite Louisa
Published: May 2011

‘Local innovation’ is a key component of the Government’s white paper on health. But what exactly is expected from the local community, and in reality how is this going to work? Bromley-by-Bow Centre may provide an answer.
Report of an evaluation of a Nurse-led Dementia Outreach Service for people with the behavioural and psychological symptoms of dementia living in residential aged care facilities
Authors: Borbasi Sally , Emmanuel Elizabeth , Farrelly Brona , Ashcroft Jayne
Published: May 2011

Background: This paper describes the implementation and evaluation of a Dementia Outreach Service (DEMOS). The service is led by the first Nurse Practitioner in Dementia Care in the State of Queensland in Australia and is highly innovative in terms of its mode of delivery. The evaluation took place due to a perception that new models such as the DEMOS often fail to gain momentum due to a lack of data on their effectiveness and efficiency.

Method: The parameters of the project were to evaluate the extent to which the DEMOS met its key deliverables, focusing specifically on outcomes for residential aged care facilities (RACF) residents and staff. The study involved both quantitative and qualitative data collection. Qualitative data was collected through interviews, focus groups and reflective journals. A survey which was administered at three stages of the 12 months of the study was the main source of quantitative data. Additional statistical data was collected from relevant healthcare providers.

Findings: Twenty RACFs within a specific health service district participated in the study. This included an intervention group of 7 facilities (which received the service) and a control group of 13. A total of 320 RACF staff participated in Stage 1 of the study, although due to staff attrition this had reduced to 153 (54.6%) at Stage 3. Attrition rates were much lower in the 7 intervention facilities, with 67.9% of the original sample remaining at Stage 3. To augment the quantitative data collected as above, drawing on a range of qualitative techniques the researchers canvassed the perceptions, thoughts and opinions of differing stakeholders. The qualitative data proved extremely valuable in confirming the success of DEMOS.

Key Success Areas: Increased self-confidence among staff in dealing with residents with dementia; reduced stress among staff; reductions in the instances of difficult behaviours; reduced referrals to acute sector services; high levels of satisfaction among RACF management regarding DEMOS; and a process of continuous improvement of DEMOS based on stakeholder feedback.

Implications for Practice: Recommendations for the future directions of the service include:

◆ The continued support and expansion of DEMOS;

◆ An increase in the DEMOS service portfolio to actively assist facilities to change the culture of care amongst RACF carers; and

◆ Showcasing of DEMOS as an example of ‘best practice’ in dementia care to argue the need for provision of additional Nurse Practitioners specializing in dementia care.
Risks and benefits of (pharmaco)epidemiology
Authors: Wise Lesley
Published: May 2011

Pharmacoepidemiology is a relatively young scientific discipline that has seen tremendous growth in interest over the past two decades. This is partly due to changes in the approval of new drugs, which often now require proactive studies to monitor and extend the knowledge of safety in the postauthorization period. Pharmacoepidemiology studies are observational in nature, in contrast to the randomized controlled trial which is the mainstay of drug development. This means that such studies need careful design and execution in order to maximize the benefits of proactive research in the ‘real-life’ clinical environment and minimize the risks of false results.
Extraction of consensus protein patterns in regions containing non-proline cis peptide bonds and their functional assessment
Authors: Exarchos Konstantinos P , Exarchos Themis P , Rigas Georgios , Papaloukas Costas , Fotiadis Dimitrios I
Published: May 2011

Background

In peptides and proteins, only a small percentile of peptide bonds adopts the cis configuration. Especially in the case of amide peptide bonds, the amount of cis conformations is quite limited thus hampering systematic studies, until recently. However, lately the emerging population of databases with more 3D structures of proteins has produced a considerable number of sequences containing non-proline cis formations (cis-nonPro).

Results

In our work, we extract regular expression-type patterns that are descriptive of regions surrounding the cis-nonPro formations. For this purpose, three types of pattern discovery are performed: i) exact pattern discovery, ii) pattern discovery using a chemical equivalency set, and iii) pattern discovery using a structural equivalency set. Afterwards, using each pattern as predicate, we search the Eukaryotic Linear Motif (ELM) resource to identify potential functional implications of regions with cis-nonPro peptide bonds. The patterns extracted from each type of pattern discovery are further employed, in order to formulate a pattern-based classifier, which is used to discriminate between cis-nonPro and trans-nonPro formations.

Conclusions

In terms of functional implications, we observe a significant association of cis-nonPro peptide bonds towards ligand/binding functionalities. As for the pattern-based classification scheme, the highest results were obtained using the structural equivalency set, which yielded 70% accuracy, 77% sensitivity and 63% specificity.
The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
Authors: Wang Ai-Hong , Duan Zhi-Jun , Tian Ge , Lu Dan , Zhang Wen-Jun , He Gao-Hong , Fang Gui-Hua
Published: May 2011

Background

We prepared an oral W/O microemulsion for the removal of colonic ammonia (ME-RCA). The effect of this microemulsion was influenced by the digestion process in the gastrointestinal tract. In this paper, we aim to show that stability was improved by using a microemulsion-based gel for the removal of colonic ammonia (MBG-RCA).

Methods

MBG-RCA was prepared by adding sodium alginate to the ME-RCA. MBG-RCA and ME-RCA were passed through a simulated gastrointestinal environment, and the amount of colonic ammonia present was then determined by titration with a standard solution of hydrochloric acid. The pH of the gastrointestinal fluid was measured using a pH test paper and the size and form of the microemulsions were examined under the microscope. 18 healthy rats were randomly divided into three groups, fasted for 24 hours and allowed to drink normally. Three-way pipes were placed at the gastroduodenal junction in Group I, and at the terminal ileum in Group II. After the intragastric administration of ME-RCA, the stomach contents in Group I, the effluent from the terminal ileum in Group II and discharge from the anus in Group III were collected. The pH values of the gastrointestinal juice were measured by the pH test paper and those of the colon were determined by a universal indicator. These animal experiments were also used to test the effect of MBG-RCA.

Results

MBG-RCA showed a better removal rate of artificial colonic ammonia than ME-RCA (P < 0.05). The decrease in pH value of the artificial small intestinal fluid due to ME-RCA did not occur when MBG-RCA was used. In the simulated gastrointestinal process, MBG-RCA maintained greater stability and released the emulsion (ME-RCA) in the colonic fluid. In the gastrointestinal tract of normal SD rats, ME-RCA decreased in size and lost its stable form after entering the small intestine, while MBG-RCA remained stable and intact emulsion-drops were observed from the anus. Neither substance had any effect on the pH of the stomach or colon of normal rats (partly because normal rats were fasted for 24 hours and allowed to drink normally, which resulted in a low level of ammonia production in the colon). Unlike ME-RCA, MBG-RCA did not reduce the pH of the small intestine.

Conclusions

MBG-RCA was more stable in the gastrointestinal tract and more effective at removing colonic ammonia when a higher concentration of ammonia was present. This made it possible to achieve the targeted removal of colonic ammonia and is a promising method to prevent hepatic encephalopathy (HE) in future studies.
Age, gender and disability predict future disability in older people: the Rotterdam Study
Authors: Taş Ümit , Steyerberg Ewout W , Bierma-Zeinstra Sita MA , Hofman Albert , Koes Bart W , Verhagen Arianne P
Published: May 2011

Background

To develop a prediction model that predicts disability in community-dwelling older people. Insight in the predictors of disability is needed to target preventive strategies for people at increased risk.

Methods

Data were obtained from the Rotterdam Study, including subjects of 55 years and over. Subjects who had complete data for sociodemographic factors, life style variables, health conditions, disability status at baseline and complete data for disability at follow-up were included in the analysis. Disability was expressed as a Disability Index (DI) measured with the Health Assessment Questionnaire.

We used a multivariable polytomous logistic regression to derive a basic prediction model and an extended prediction model. Finally we developed readily applicable score charts for the calculation of outcome probabilities.

Results

Of the 5027 subjects included, 49% had no disability, 18% had mild disability, 16% had severe disability and 18% had deceased at follow-up after six years. The strongest predictors were age and prior disability. The contribution of other predictors was relatively small. The discriminative ability of the basic model was high; the extended model did not enhance predictive ability.

Conclusion

As prior disability status predicts future disability status, interventive strategies should be aimed at preventing disability in the first place.
Single nucleotide polymorphisms at the TRAF1/C5 locus are associated with rheumatoid arthritis in a Han Chinese population
Authors: Zhu Jing , Zhang Dinging , Wu Fengxia , He Fei , Liu Xiaoqi , Wu Lijun , Zhou Bin , Liu Jianping , Lu Fang , Liu Jian , Luo Ruijun , Long Wubin , Yang Minghui , Ma Shi , Wu Xiaodan , Shi Yi , Wu Tong , Lin Ying , Yang Jiyun , Yuan Guohua , Yang Zhenglin
Published: May 2011

Background

Genetic variants inTRAF1C5andPTPN22genes have been shown to be significantly associated with arthritis rheumatoid in Caucasian populations. This study investigated the association between single nucleotide polymorphisms (SNPs) inTRAF1/C5andPTPN22genes and rheumatoid arthritis (RA) in a Han Chinese population. We genotyped SNPs rs3761847 and rs7021206 at theTRAF1/C5locus and rs2476601 SNP in thePTPN22gene in a Han Chinese cohort composed of 576 patients with RA and 689 controls. The concentrations of anti-cyclic citrullinated peptide antibodies (CCP) and rheumatoid factor (RF) were determined for all affected patients. The difference between the cases and the controls was compared usingχ2analysis.

Results

Significant differences in SNPs rs3761847 and rs7021206 atTRAF1/C5were observed between the case and control groups in this cohort; the allelic p-value was 0.0018 with an odds ratio of 1.28 for rs3761847 and 0.005 with an odds ratio of 1.27 for rs7021206. This significant association between rs3761847 and RA was independent of the concentrations of anti-CCP and RF. No polymorphism of rs2476601 was observed in this cohort.

Conclusions

We first demonstrated that genetic variants at theTRAF1/C5locus are significantly associated with RA in Han Chinese, suggesting thatTRAF1/C5may play a role in the development of RA in this population, which expands the pathogenesis role ofTRAF1/C5in a different ethnicity.
Varicella-zoster virus infections in immunocompromised patients - a single centre 6-years analysis
Authors: Wiegering Verena , Schick Judith , Beer Meinrad , Weissbrich Benedikt , Gattenlöhner Stefan , Girschick Hermann J , Liese Johannes , Schlegel Paul G , Eyrich Matthias
Published: May 2011

Background

Infection with varicella-zoster virus (VZV) contemporaneously with malignant disease or immunosuppression represents a particular challenge and requires individualized decisions and treatment. Although the increasing use of varicella-vaccines in the general population and rapid initiation of VZV-immunoglobulins and acyclovir in case of exposure has been beneficial for some patients, immunocompromised individuals are still at risk for unfavourable courses.

Methods

In this single center, 6-year analysis we review incidence, hospitalization and complication rates of VZV-infections in our center and compare them to published data. Furthermore, we report three instructive cases.

Results

Hospitalization rate of referred children with VZV-infections was 45%, among these 17% with malignancies and 9% under immunosuppressive therapy. Rate of complications was not elevated in these two high-risk cohorts, but one ALL-patient died due to VZV-related complications. We report one 4-year old boy with initial diagnosis of acute lymphoblastic leukemia who showed a rapidly fatal outcome of his simultaneous varicella-infection, one 1.8-year old boy with an identical situation but a mild course of his disease, and an 8.5-year old boy with a steroid-dependent nephrotic syndrome. This boy developed severe hepatic involvement during his varicella-infection but responded to immediate withdrawl of steroids and administration of acyclovir plus single-dose cidofovir after nonresponse to acyclovir after 48 h.

Conclusion

Our data show that patients with malignant diseases or immunosuppressive therapy should be hospitalized and treated immediately with antiviral agents. Despite these measures the course of VZV-infections can be highly variable in these patients. We discuss aids to individual decision-making for these difficult situations.
Breast cancer screening in the Czech Republic: time trends in performance indicators during the first seven years of the organised programme
Authors: Majek Ondrej , Danes Jan , Skovajsova Miroslava , Bartonkova Helena , Buresova Lucie , Klimes Daniel , Brabec Petr , Kozeny Pavel , Dusek Ladislav
Published: May 2011

Background

The Czech Breast Cancer Screening Programme (CBCSP) was initiated in September 2002 by establishing a network of accredited centres. The aim of this article is to describe progress in the programme quality over time after the inception of the organised programme.

Methods

The CBCSP is monitored using an information system consisting of three principal components: 1) the national cancer registry, 2) a screening registry collecting data on all screening examinations, further assessments and final diagnoses at accredited programme centres, and 3) administrative databases of healthcare payers. Key performance indicators from the European Guidelines have been adopted for continuous monitoring.

Results

Breast cancer incidence in the Czech Republic has steadily been increasing, however with a growing proportion of less advanced stages. The mortality rate has recently stabilised. The screening registry includes 2,083,285 records on screening episodes between 2002 and 2008. In 2007-2008, 51% of eligible women aged 45-69 were screened. In 2008, the detection rates were 6.1 and 3.7 per 1,000 women in initial and subsequent screening respectively. Corresponding recall rates are 3.9% and 2.2%, however, it is necessary to pay attention to further assessment performed during the screening visits. Benign to malignant open biopsy ratio was 0.1. Of invasive cases detected in screening, 35.6% was less than 10 mm in diameter. Values of early performance indicators, as measured by both crude and standardized estimates, are generally improving and fulfil desirable targets set by European Guidelines.

Conclusions

Mammography screening in the Czech Republic underwent successful transformation from opportunistic prevention to an organised programme. Values of early indicators confirm continuous improvement in different aspects of process quality. Further stimulation of participation through invitation system is necessary to exploit the full potential of screening mammography at the population level.
Crystal structures of a halophilic archaeal malate synthase from Haloferax volcanii and comparisons with isoforms A and G
Authors: Bracken Colten D , Neighbor Amber M , Lamlenn Kenneth K , Thomas Geoffrey C , Schubert Heidi L , Whitby Frank G , Howard Bruce R
Published: May 2011

Background

Malate synthase, one of the two enzymes unique to the glyoxylate cycle, is found in all three domains of life, and is crucial to the utilization of two-carbon compounds for net biosynthetic pathways such as gluconeogenesis. In addition to the main isoforms A and G, so named because of their differential expression in E. coli grown on either acetate or glycolate respectively, a third distinct isoform has been identified. These three isoforms differ considerably in size and sequence conservation. The A isoform (MSA) comprises ~530 residues, the G isoform (MSG) is ~730 residues, and this third isoform (MSH-halophilic) is ~430 residues in length. Both isoforms A and G have been structurally characterized in detail, but no structures have been reported for the H isoform which has been found thus far only in members of the halophilic Archaea.

Results

We have solved the structure of a malate synthase H (MSH) isoform member from Haloferax volcanii in complex with glyoxylate at 2.51 Å resolution, and also as a ternary complex with acetyl-coenzyme A and pyruvate at 1.95 Å. Like the A and G isoforms, MSH is based on a β8/α8 (TIM) barrel. Unlike previously solved malate synthase structures which are all monomeric, this enzyme is found in the native state as a trimer/hexamer equilibrium. Compared to isoforms A and G, MSH displays deletion of an N-terminal domain and a smaller deletion at the C-terminus. The MSH active site is closely superimposable with those of MSA and MSG, with the ternary complex indicating a nucleophilic attack on pyruvate by the enolate intermediate of acetyl-coenzyme A.

Conclusions

The reported structures of MSH from Haloferax volcanii allow a detailed analysis and comparison with previously solved structures of isoforms A and G. These structural comparisons provide insight into evolutionary relationships among these isoforms, and also indicate that despite the size and sequence variation, and the truncated C-terminal domain of the H isoform, the catalytic mechanism is conserved. Sequence analysis in light of the structure indicates that additional members of isoform H likely exist in the databases but have been misannotated.
Quantum dots: a new tool for anti-malarial drug assays
Authors: Ku Min-Je , Dossin Fernando M , Choi Youngseon , Moraes Carolina B , Ryu Jiyoung , Song Rita , Freitas-Junior Lucio H
Published: May 2011

Background

Malaria infects over 300 million people every year and one of the major obstacles for the eradication of the disease is parasite's resistance to current chemotherapy, thus new drugs are urgently needed. Quantum dot (QD) is a fluorescent nanocrystal that has been in the spotlight as a robust tool for visualization of live cell processes in real time. Here, a simple and efficient method using QD to directly label Plasmodium falciparum-infected erythrocytes (iRBCs) was searched in order to use the QD as a probe in an anti-malarial drug-screening assay.

Methods

A range of QDs with different chemical coatings were tested for their ability to specifically bind iRBCs by immunofluorescence assay (IFA). One QD was selected and used to detect parasite growth and drug sensitivity by flow cytometry.

Results

PEGylated-cationic QD (PCQD) was found to specifically label infected erythrocytes preferentially with late stage parasites. The detection of QD-labelled infected erythrocytes by flow cytometry was sensitive enough to monitor chloroquine anti-malarial toxicity with a drug incubation period as short as 24 h (EC50 = 113nM). A comparison of our assay with another widely used anti-malarial drug screening assay, the pLDH assay, showed that PCQD-based assay had 50% improved sensitivity in detecting drug efficacy within a parasite life cycle. An excellent Z-factor of 0.8 shows that the QD assay is suitable for high-throughput screening.

Conclusions

This new assay can offer a rapid and robust platform to screen novel classes of anti-malarial drugs.