How diet modification challenges are magnified in vulnerable or marginalized people with diabetes and heart disease: a systematic review and qualitative meta-synthesis

BACKGROUND

Diet modification is an important part of self-management for patients with diabetes and/or heart disease (including coronary artery disease, heart failure, and atrial fibrillation). Many health care providers and community-based programs advise lifestyle and diet modification as part of care for people with these conditions. This report synthesizes qualitative information on how patients respond differently to the challenges of diet modification. Qualitative and descriptive evidence can illuminate challenges that may affect the success and equitable impact of dietary modification interventions.

OBJECTIVES

To (a) examine the diet modification challenges faced by diabetes and/or heart disease patients; and (b) compare and contrast the challenges faced by patients who are members of vulnerable and nonvulnerable groups as they change their diet in response to clinical recommendations.

DATA SOURCES

This report synthesizes 65 primary qualitative studies on the topic of dietary modification challenges encountered by patients with diabetes and/or heart disease. Included papers were published between 2002 and 2012 and studied adult patients in North America, Europe, and Australia/New Zealand.

REVIEW METHODS

Qualitative meta-synthesis was used to integrate findings across primary research studies.

RESULTS

Analysis identified 5 types of challenges that are common to both vulnerable and nonvulnerable patients: self-discipline, knowledge, coping with everyday stress, negotiating with family members, and managing the social significance of food. Vulnerable patients may experience additional barriers, many of which can magnify or exacerbate those common challenges.

LIMITATIONS

While qualitative insights are robust and often enlightening for understanding experiences and planning services in other settings, they are not intended to be generalizable. The findings of the studies reviewed here--and of this synthesis--do not strictly generalize to the Ontario (or any specific) population. This evidence must be interpreted and applied carefully, in light of expertise and the experiences of the relevant community.

CONCLUSIONS

Diet modification is not simply a matter of knowing what to eat and making the rational choice to change dietary practices. Rather, diet and eating practices should be considered as part of the situated lives of patients, requiring an individualized approach that is responsive to the conditions in which each patient is attempting to make a change. Common challenges include self-discipline, knowledge, coping with everyday stress, negotiating with family members, and managing the social significance of food. An individualized approach is particularly important when working with patients who have vulnerabilities.

PLAIN LANGUAGE SUMMARY

Health care providers often encourage people with diabetes and/or heart disease to change their diet. They advise people with diabetes to eat less sugar, starch, and fat. They advise people with heart disease to eat less fat and salt. However, many patients find it difficult to change what they eat. This report examines the challenges people may face when making such changes. It also examines the special challenges faced by people who are vulnerable due to other factors, such as poverty, lack of education, and difficulty speaking English. Five themes were common to all people who make diet changes: self-discipline, knowledge, coping with stress, negotiating with family members, and managing the social aspect of food. Members of vulnerable groups also reported other challenges, such as affording fresh fruit and vegetables or understanding English instructions. This report may help health care providers work with patients more effectively to make diet changes.

Patient experiences of depression and anxiety with chronic disease: a systematic review and qualitative meta-synthesis

BACKGROUND

Depression and anxiety are highly prevalent in patients with chronic disease, but remain undertreated despite significant negative consequences on patient health. A number of clinical groups have developed recommendations for depression screening practices in the chronic disease population.

OBJECTIVES

The objective of this analysis was to review empirical qualitative research on the experiences of patients with chronic disease (e.g., COPD, diabetes, heart disease, stroke) and comorbid depression or anxiety, and to highlight the implications of the screening and management of anxiety and/or depression on chronic disease outcomes.

REVIEW METHODS

We performed literature searches for studies published from January 2002 to May 2012. We applied a qualitative mega-filter to nine condition-specific search filters. Titles and abstracts were reviewed by two reviewers and, for the studies that met the eligibility criteria, full-text articles were obtained. Qualitative meta-synthesis was used to integrate findings across relevant published primary research studies. Qualitative meta-synthesis produced a synthesis of evidence that both retained the original meaning of the authors and offered a new, integrative interpretation of the phenomenon through a process of comparing and contrasting findings across studies.

RESULTS

The findings of 20 primary qualitative studies were synthesized. Patients tended to experience their chronic conditions and anxiety or depression as either independent or inter-related (i.e., the chronic disease lead to depression/anxiety, the depression/anxiety lead to the chronic disease, or the two conditions exacerbated each other). Potential barriers to screening for depression or anxiety were also identified.

LIMITATIONS

A wider array of issues might have been captured if the analysis had focused on broader psychological responses to the chronic disease experience. However, given the objective to highlight implications for screening for anxiety or depression, the more narrow focus seemed most relevant.

CONCLUSIONS

Chronic disease and anxiety or depression can be independent or inter-related. Patients may be reluctant to acknowledge depression or anxiety as a separate condition, or may not recognize that the conditions are separate because of overlapping physical symptoms. More qualitative research is needed to specifically address screening for depression or anxiety.

PLAIN LANGUAGE SUMMARY

Depression is a common complication of chronic disease. It may worsen the disease, and it may also affect the self-management of the disease. Screening for depression earlier, and then treating it, may reduce distress and improve symptoms of the chronic disease, leading to better quality of life.

Multicentre clinical trials' data management: a hybrid solution to exploit the strengths of electronic data capture and electronic health records systems

BACKGROUND

Clinical Trials (CTs) are indispensable instruments for evidence-based medicine and frequently necessitate the management, sharing and analysis of large amounts of data amongst partners in different locations.

METHODS

To effectively satisfy these requirements, the proposed solution combines a web platform and a Clinical Data Management System (CDMS) to exploit the strengths of Electronic Health Records (EHR) and Electronic Data Capture (EDC) systems. The core of the proposal is a relational database which has high data structuring characteristics and utilises biomedical controlled vocabularies (e.g. LOINC and ICD). In addition, units and normality ranges were collected for data comparison through the application of the Z-score transformation.

RESULTS

The obtained CDMS preserves the EDC's flexibility and user autonomy and permits the creation of patient cohorts, as in the EHR. Accordingly, clinical information, after the initial recording, is available for different simultaneous multicentre CTs. Furthermore, interface runtime controls guarantee high data quality during data entering processes. Currently, the proposed system has been developed in the HIV and eye diseases fields in Italy.

CONCLUSIONS

The proposed solution is flexible and suitable to perform multicentre research within a varying range of medical domains. In the future, the automatic importation of information from hospitals has been planned through an HL7 standard interface which would improve both data quantity and quality.

The ligurian human immunodeficiency virus clinical network: a web tool to manage patients with human immunodeficiency virus in primary care and multicenter clinical trials

Background

In recent years, Highly-Active Anti-Retroviral Therapies (HAARTs) have modified the Human Immunodeficiency Virus (HIV) life-cycle and the disease is now considered chronic. Consequently, a longitudinal and complex follow-up is now required for HIV positive patients during their lifetime. Moreover, patients often encounter various complications due to comorbidities, related to the immunodeficiency state and HAARTs’ side effects. Thus, HIV positive patients are involved in multicenter clinical trials (MCTs) to improve treatments and discover a preventive vaccine. Therefore, physicians require proper instruments to access comprehensive patient data for managing patients during follow-ups, and tools for data collection and analysis in MCTs.

Objective

The Ligurian HIV Clinical Network aims to provide physicians with a Web-tool to administrate HIV positive patients’ data within primary-care and to reuse the collected clinical information to perform MCTs in Northern Italy.

Methods

The key aspect of the system is a relational database which allows the storage of various types of clinical information (eg, related to HIV, cardiovascular, or hepatic diseases) in multiple formats. The modular design of the database permits a rapid insertion of new parameters without requiring any changes in the database structure. Furthermore, codes from biomedical ontologies controlled vocabularies (“Logical Observation Identifier Names and Codes”, and “International Classification of Diseases 9”) and ontologies (“Systematized Nomenclature of Medicine Clinical Terms”), units and normality ranges used by all partners participating in the project were collected to achieve a complete semantic interoperability. Accordingly, data can be automatically normalized through the z score formula and physicians can extract and correctly compare information with external statistical tools. Moreover, to respect patients’ privacy and legal issues, a local identifier, determined through an HASH cryptography algorithm, is assigned to each patient during the registration process. The database is managed by a user-friendly Web-platform which allows quick access to information during medical examinations and the reusing of the collected data for present and future MCTs. Furthermore, a bidirectional middleware was created in order to import/export information through HL7 messaging. Hence, data can be manually entered by physicians or automatically collected within HL7-compliant Hospital Information systems.

Results

Presently, the direct storage of patients’ information from the San Paolo Hospital (Savona, Italy), and San Martino and Galliera hospitals in Genoa is in a test phase. Currently, 8 centers of Infectious Diseases (located in Liguria and Piedmont) are participating in the project and almost 400 HIV positive patients have been recorded in the system. Patient data has been used for primary care and research purposes. Currently, there are 4 on-going MCTs and preliminary results have already been presented at International HIV congresses.

Conclusions

The Web-platform allows effective management, sharing and reuse of information within primary care and clinical research. In the future it is planned to share the clinical information from this network with other HL7-compliant workgroups and to extend the platform to other infective diseases (eg, hepatitis).

Entropy-driven decision tree building for decision support in gastroenterology

Gastroesophageal reflux disease is a serious clinical problem, which can significantly impair health-related quality of life, thus having global implications for patients. The first step for a doctor is the clinical classification of the patients, divided into classes after being subjected to endoscopic examinations to control if there are lesions of the esophageal mucosa, and if present, the severity of these lesions. 269 patients were taken into consideration (4 healthy patients, 219 with non erosive reflux disease, 21 with erosive reflux disease, 15 with complicated erosive reflux disease, 10 with Barrett's disease). A set of values taken from gastroscopy, ph-metry and manometry tests were considered and a decision tree was made to classify every patient. Entropy and information gain were calculated for each node to create the most possible simple tree. The resulting tree presents some paths including a significant number of persons; the values that build these paths can be considered characteristic of each class of patient. This method can be a basis to develop a diagnostic decision support for a training doctor starting from a set of characteristics, specific to a class of patient.

Intraspecific diversity of Edwardsiella ictaluri isolates from diseased freshwater catfish, Pangasianodon hypophthalmus (Sauvage), cultured in the Mekong Delta, Vietnam

A molecular epidemiology study was conducted on 90 Edwardsiella ictaluri isolates recovered from diseased farmed freshwater catfish, Pangasianodon hypophthalmus, cultured in the Mekong Delta, Vietnam. Thirteen isolates of E. ictaluri derived from diseased channel catfish, Ictalurus punctatus, cultured in the USA were included for comparison. All the E.ictaluri isolates tested were found to be biochemically indistinguishable. A repetitive (rep)-PCR using the single (GTG)(5) primer was shown to possess limited discriminatory power, yielding two similar DNA profiles categorized as (GTG)(5) -PCR group 1 or 2 among the Vietnam isolates and (GTG)(5) -PCR group 1 within the USA isolates. Macrorestriction analysis identified 14 and 22 unique pulsotypes by XbaI and SpeI, respectively, among a subset of 59 E. ictaluri isolates. Numerical analysis of the combined macrorestriction profiles revealed three main groups: a distinct cluster formed exclusively of the USA isolates, and a major and minor cluster with outliers contained the Vietnam isolates. Antibiotic susceptibility and plasmid profiling supported the existence of the three groups. The results indicate that macrorestriction analysis may be regarded as a suitable typing method among the E. ictaluri species of limited intraspecific diversity. Furthermore, the findings suggest that E. ictaluri originating from Vietnam may constitute a distinct genetic group.

Experiences of living and dying with COPD: a systematic review and synthesis of the qualitative empirical literature

Objective of Analysis

The objective of this analysis was to review empirical qualitative research on the experiences of patients with chronic obstructive pulmonary disease (COPD ), informal caregivers (“carers”), and health care providers—from the point of diagnosis, through daily living and exacerbation episodes, to the end of life.

Clinical Need and Target Population

Qualitative empirical studies (from social sciences, clinical, and related fields) can offer important information about how patients experience their condition. This exploration of the qualitative literature offers insights into patients’ perspectives on COPD, their needs, and how interventions might affect their experiences. The experiences of caregivers are also explored.

Research Question

What do patients with COPD, their informal caregivers (“carers”), and health care providers experience over the course of COPD?

Research Methods

Summary of Findings

A standardized middleware as the core of a telemonitoring European Project

In order to develop smart and innovative solutions which are able to realize the concept of care continuum, the use of a number of different multiple devices, based on heterogeneous technologies, is necessary. In this complex context it is important to study and design systems whose architecture ensure the interoperability between devices and service. A standardized middleware which is able to guarantee this important requirement within the European Project CHIRON, is presented in this article.

A web-based tool for patients cohorts and Clinical Trials management

Clinical Trials (CTs) play an increasingly important role in modern medicine. Often these types of studies, especially in the final phases, require collaboration between several hospitals, laboratories and institutions in different places or countries. The solution proposed is a template which exploits the principles of Networked Clinical Research and the strengths of Clinical Data Management Systems (CDMSs) commonly used (Electronic Data Capture (EDC), Electronic Medical Record (EMR) and Electronic Health Record (EHR). Therefore, the basic structure is a highly normalized and standardized database which is managed by a web platform and, only by recording the required information and developing web pages starting from predefined templates, it is possible to carry out new projects. The result is a hybrid CDMS which preserves the flexibility and user autonomy of EDC systems; and contemporarily, permits the creation of patients cohorts, as in EMR and EHR systems, in which to realize simultaneously different multicentric CTs in several medical fields.

Ionic channel current burst analysis by a machine learning based approach

A new method to analyze single ionic channel current conduction is presented. It is based on an automatic classification by K-means algorithm and on the concept of information entropy. This method is used to study the conductance of multistate ion current jumps induced by tetanus toxin in planar lipid bilayers. A comparison is presented with the widely used Gaussian best fit approach, whose main drawback is the fact that it is based on the manual choice of the base line and of meaningful fragments of current signal. On the contrary, the proposed method is able to automatically process a great amount of information and to remove spurious transitions and multichannels. The number of levels and their amplitudes do not have to be known a priori. In this way the presented method is able to produce a reliable evaluation of the conductance levels and their characteristic parameters in a short time.

Data Modeling for Tools and Technologies for the Analysis and Synthesis of NANOstructures (TASNANO) Project

The main aim of TASNANO project is to focus on the development of a web-based system that allows cooperative work between partners. Even if some commercial tools become available, the specificities of nanotechnology applications suggest implementing an ad-hoc tool. This approach permits to update information every moment, so that not only the latest versions of the documents are always available, but also the raw experimental data are shared in a protected environment. Organizing big amount of data begins with modeling of conceptual schemes, which individualizes entities involved into the project and links between them. The rules’ application of logic modeling leads to the production of a logic scheme. The model allows the data base design, which can be enlarged and enriched preserving coherence and avoiding redundancy. Data and information can be directly treated on the web in accordance with latest modifications.

Duty to disclose what? Querying the putative obligation to return research results to participants

Many research ethics guidelines now oblige researchers to offer research participants the results of research in which they participated. This practice is intended to uphold respect for persons and ensure that participants are not treated as mere means to an end. Yet some scholars have begun to question a generalised duty to disclose research results, highlighting the potential harms arising from disclosure and questioning the ethical justification for a duty to disclose, especially with respect to individual results. In support of this view, we argue that current rationales for a duty of disclosure do not form an adequate basis for an ethical imperative. We review policy guidance and scholarly commentary regarding the duty to communicate the results of biomedical, epidemiological and genetic research to research participants and show that there is wide variation in opinion regarding what should be disclosed and under what circumstance. Moreover, we argue that there is fundamental confusion about the notion of "research results," specifically regarding three core concepts: the distinction between aggregate and individual results, amongst different types of research, and across different degrees of result veracity. Even where policy guidance and scholarly commentary have been most forceful in support of an ethical imperative to disclose research results, ambiguity regarding what is to be disclosed confounds ethical action.

A drug delivery system for the treatment of peripheral nervous system injuries

Recent results in biomedical engineering and materials science and technology have brought about the development of novel bioactive materials by which the repair of peripheral nervous system injuries can be improved. The formation of scarring tissue, which represents a physical barrier to axon elongation, and the not oriented outgrowth of neurites are the two major obstacles for a complete recovery of physiological nerve function. This study mainly focuses on the analysis of biocompatible constructs for the controlled release of anti-scarring antibodies by means of fluorescence spectroscopy techniques.

Mathematical Modeling of Retinal Mosaic Formation by Mechanical Interactions and Dendritic Overlap

The retina is a complex assembly of neurons packed into a three-layer structure containing five classes of cells. Each class of retinal cells is regularly arranged within its layer in an orderly configuration called the retinal mosaic. We have set up a mathematical model of retinal mosaic formation focusing on the actions of local mechanical forces on the neuron's cytoskeleton. The cytoskeleton has been modeled according to two approaches, one based on the tensegrity concept (a structure made of elastic and rigid elements), and the other based on a simple model with viscoelastic features. We have assumed causing deformation of their cytoskeleton, overlap of dendritic areas and movement of the neuron. Simulations based on these two models indicate that a random distribution of neurons reaches an orderly configuration by local and mechanical neuron interaction in the case in which the cytoskeleton is modeled using the tensegrity approach, but not when the neuron is modeled as a purely viscoelastic system. Considering that the main structural difference between the Maxwell model and the tensegrity model is that the latter model contains rigid elements whereas the former does not, this suggests that the presence of rigid components in the cytoskeleton of retinal neurons plays a key role in the formation processes of the retinal mosaic.

Biodiversity of chloramphenicol-resistant mesophilic heterotrophs from Southeast Asian aquaculture environments

In the present study, samples of pond water, sediment and farmed species were collected at 12 fish and shrimp farms in Malaysia, Thailand and Vietnam to determine the biodiversity and environmental distribution of chloramphenicol-resistant (CmR) mesophilic heterotrophs in Southeast Asian aquaculture sites. Following isolation on Iso-Sensitest agar supplemented with 35mug ml(-1) Cm and dereplication using (GTG)(5)-PCR fingerprinting, 557 genotypically unique CmR strains were subjected to polyphasic identification. The 557 mesophilic heterotrophic CmR isolates represented 18 different genera largely dominated by the genera Escherichia (40.2%), Pseudomonas (11.7%), Acinetobacter (11.1%), Klebsiella (7.5%) and Bacillus (5.9%). A total of 439 CmR isolates were further assigned to 31 described species or species groups, mainly including organisms that have been associated with various human opportunistic infections such as Escherichia coli (n=219), Pseudomonas putida (n=47), Klebsiella pneumoniae (n=38) and Acinetobacter baumannii (n=23). Strains of Escherichia, and most notably, of E. coli, were the only common group of CmR heterotrophs irrespective of country, sample type or farm type. Together with other predominant but less widespread groups such as acinetobacters and pseudomonads, the results of this biodiversity study suggest that E. coli can be regarded as a potential indicator of Cm resistance in Southeast Asian aquaculture environments.

Withholding and withdrawing life support in critical care settings: ethical issues concerning consent

The right to refuse medical intervention is well established, but it remains unclear how best to respect and exercise this right in life support. Contemporary ethical guidelines for critical care give ambiguous advice, largely because they focus on the moral equivalence of withdrawing and withholding care without confronting the very real differences regarding who is aware and informed of intervention options and how patient values are communicated and enacted. In withholding care, doctors typically withhold information about interventions judged too futile to offer. They thus retain greater decision-making burden (and power) and face weaker obligations to secure consent from patients or proxies. In withdrawing care, there is a clearer imperative for the doctor to include patients (or proxies) in decisions, share information and secure consent, even when continued life support is deemed futile. How decisions to withhold and withdraw life support differ ethically in their implications for positive versus negative interpretations of patient autonomy, imperatives for consent, definitions of futility and the subjective evaluation of (and submission to) benefits and burdens of life support in critical care settings are explored. Professional reflection is required to respond to trends favouring a more positive interpretation of patient autonomy in the context of life support decisions in critical care. Both the bioethics and critical care communities should investigate the possibilities and limits of growing pressure for doctors to disclose their reasoning or seek patient consent when decisions to withhold life support are made.

Development of a piezoelectric immunosensor for the measurement of paclitaxel

This paper describes the development of a piezoelectric immunosensor for the measurement of paclitaxel (taxol), a natural anti-cancer agent. An antibody specific for taxanes was immobilized onto the surface of quartz crystals by means of the layer-by-layer self-assembly technique. The immobilization was achieved using electrostatic interactions between a precursor layer and the antibody molecules. The assembly process was monitored by a quartz crystal microbalance (QCM) and the topography of the modified quartz crystals was investigated by means of atomic force microscopy. The specific interaction of the immobilized antibody with paclitaxel in solution at different concentrations was monitored as a change in resonant frequency of the modified crystal. Moreover, the influence of non-specific adsorption was also characterized. The results show that the proposed immunosensor offers a promising alternative to classical analytical methods for a fast and easy determination of paclitaxel.

Metabolic treatment of critically ill patients: energy expenditure and energy supply

Nutrition in critically ill patients should be considered as therapy: assessing the energy expenditure and the termogenic effect of food, and knowing the differences among composition and amount of given substrates, it is possible restore, maintain, or at least limit the derangement of energy equilibrium. Energy metabolism comprehends assumption, storage and oxidation of nutrients: all these factors could be discriminant in critical clinical conditions, particularly cardiac and respiratory failure. Then, this review would lead the decision making process beginning from biochemistry and bioenergetics, until the metabolic strategy practically usable at the bedside of patients during the whole critical phase of their pathology.

Decision tools for life support: a review and policy analysis

OBJECTIVE

To identify, describe, and compare published documents intended to guide decisions about the administration, withholding, or withdrawal of life support in critical care.

DESIGN

Review article. SETTING AND SOURCES: Publicly available, English-language guidelines or decision tools for life support, identified through systematic literature search.

MEASUREMENTS AND MAIN RESULTS

Forty-nine documents were included and coded for authorship, source, development methodology, format, and positions taken on 12 common life-support issues. Sources were independent academics (n=21, 43%), professional organizations (n=19, 44%), and provider organizations. Eighteen documents (37%) described no development method. Twenty-three (47%) were produced collectively (e.g., by committees or consensus conference), 7 (14%) mentioned a literature review, and 2 (4%) were based upon the author's professional experience. Tools differed in format and focus; we characterize three types as decision schemas (involving clinical practice algorithms; n=7, 14%), decision guides (reviewing legal or professional positions; n=29, 59%), and decision counsels (more discursive and focusing typically on ethical issues; n=13, 27%). Tools addressed 12 common life-support issues: advance directives (67%), resource considerations (51%), ICU discharge criteria (27%), ICU admission criteria (16%), whether withholding differs from withdrawing life support (59%), whether nutrition and hydration decisions are different from decisions about other types of life support (61%), euthanasia (49%), double effect (47%), brain death (35%), special considerations for patients in a persistent vegetative state (51%), potential organ donors (12%), and pregnant patients (10%). Positions on these key life-support issues varied.

CONCLUSIONS

Published tools for guiding life-support decisions vary widely in their genesis, authorship, format, focus, and practicality. They also differ in their attention to, and positions on, key life-support dilemmas. Future research on decision tools should focus on how users interpret and apply the messages in these tools and their impacts on practice, quality of care, participant experiences, and outcomes.

An Experience of Microbiological Data Sharing

Objectives: The control of infections and their resistance to antibiotics in hospitals is a matter of vital importance in the follow-up of transplant patients. This project has the purpose of translating microbiological reports from an obsolete file structure to a system which could guarantee a more correct and quick transmission of data, a system of storage which reduces the possibility of errors, a smoother manipulation, consultation and updating of data and, at least, a simple way to compute the cost of analysis, based on the costs determined by the national’s DRG.

Methods: The proposed solution is a semiautomatic interface which translates these data into a relational database on a daily basis, interprets the requests coming from external centers and produces reports. The prospective to use this tool for several centers indicates to us the need to choose an HL7 output for the interface.

Results: A prototype version of this program was installed in February 2004. In this period, routine work has been recorded with an average of 6.5 samples per day, with a maximum of 23 samples. Moreover, historical data from 1998 has been translated. The main source of errors in these data was due to patient identification problems with an average occurrence of 4.06% in the virology section and of 4.16% in the microbiological division.

Conclusions: A complete reorganization of the system would be desirable but at the moment it is not realistic because of obvious budget problems. The proposed approach, mainly the HL7 interface, seems to be a reasonable compromise.

An experience of microbiological data sharing

OBJECTIVES

The control of infections and their resistance to antibiotics in hospitals is a matter of vital importance in the follow-up of transplant patients. This project has the purpose of translating microbiological reports from an obsolete file structure to a system which could guarantee a more correct and quick transmission of data, a system of storage which reduces the possibility of errors, a smoother manipulation, consultation and updating of data and, at least, a simple way to compute the cost of analysis, based on the costs determined by the national's DRG.

METHODS

The proposed solution is a semiautomatic interface which translates these data into a relational database on a daily basis, interprets the requests coming from external centers and produces reports. The prospective to use this tool for several centers indicates to us the need to choose an HL7 output for the interface.

RESULTS

A prototype version of this program was installed in February 2004. In this period, routine work has been recorded with an average of 6.5 samples per day, with a maximum of 23 samples. Moreover, historical data from 1998 has been translated. The main source of errors in these data was due to patient identification problems with an average occurrence of 4.06% in the virology section and of 4.16% in the microbiological division.

CONCLUSIONS

A complete reorganization of the system would be desirable but at the moment it is not realistic because of obvious budget problems. The proposed approach, mainly the HL7 interface, seems to be a reasonable compromise.

Intra- and interlaboratory performance of antibiotic disk-diffusion-susceptibility testing of bacterial control strains of relevance for monitoring aquaculture environments

In the course of an international research project on hazard analysis of antimicrobial resistance in SE Asian aquaculture environments, 2 European Union and 3 SE Asian laboratories attempted to harmonize a procedure for antimicrobial agent susceptibility testing based on disk diffusion (DD). For this purpose, a selected panel of 10 bacterial control strains of relevance for monitoring warm-water aquaculture environments was sent by the central laboratory to the other participating laboratories. In each laboratory, 10 independently replicated DD determinations of each control strain to 6 antibiotics were performed using Iso-Sensitest Agar (ISA) according to a standard operating procedure (SOP); in total, this study thus yielded 300 data sets for all 5 laboratories. At the end of the study, strain authenticity of subcultures of the control strains used by the respective participating laboratories was verified by the central laboratory. Based on the arithmetic mean of 10 inhibition-zone diameter measurements and standard deviation (SD), intralaboratory SD variations ranged from 0 to 2 mm when 79% of the recorded data sets were considered. In 8% of the data sets, the SD value exceeded 4 mm, which in most cases could be attributed to the fact that the data points for a given strain-disk combination were not normally distributed in one of the laboratories. At the interlaboratory level, 81% of the SD values based on global averaging of 50 data points per strain-disk combination were situated in the 0 to 5 mm range. Comparison with a minimal data set from literature of DD testing performed with Mueller-Hinton (MH) medium indicated that the use of either ISA or MH medium in DD testing has a limited impact on the method's precision among different laboratories. In conclusion, the current study has provided a validated SOP to promote the coordination and harmonization of DD-susceptibility methodologies for aquaculture-associated organisms at an international level. As one of the main action items for the future, new interpretive breakpoints should be specifically designed and validated for aquaculture drugs and organisms.

Mathematical model of retinal mosaic formation

The retina is one of the best examples of modular organisation in neural circuitry. This modular structure enables it to perform parallel processing. A mathematical model of the retina has been set up, focusing on mechanical features of retinal neurons and on the interaction and dendritic overlapping among retinal cells. The model focuses on the actions of local mechanical forces on the neuron's cytoskeleton. The cytoskeleton is regarded as a structure in which elastic and rigid elements are combined according to the tensegrity concept. We have assumed that dendritic overlap takes place in such a way as to favour uniform retinal neurons' distribution and that dendritic overlap is the only cause of neuron's motion on the retinal surface. This overlap depends on the growth of the dendrites due to the cytoskeletic deformation. The results obtained are in agreement with experimental results that support the notion that local mechanical interaction and dendritic overlapping are capable to transform random cell distributions into regular mosaics.