Polyhydroxyalknoate synthesis in plants as a tool for biotechnology and basic studies of lipid metabolism.

Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyacids naturally synthesized in bacteria as a carbon reserve. PHAs have properties of biodegradable thermoplastics and elastomers and their synthesis in crop plants is seen as an attractive system for the sustained production of large amounts of polymers at low cost. A variety of PHAs having different physical properties have now been synthesized in a number of transgenic plants, including Arabidopsis thaliana, rape and corn. This has been accomplished through the creation of novel metabolic pathways either in the cytoplasm, plastid or peroxisome of plant cells. Beyond its impact in biotechnology, PHA production in plants can also be used to study some fundamental aspects of plant metabolism. Synthesis of PHA can be used both as an indicator and a modulator of the carbon flux to pathways competing for common substrates, such as acetyl-coenzyme A in fatty acid biosynthesis or 3-hydroxyacyl-coenzyme A in fatty acid degradation. Synthesis of PHAs in plant peroxisome has been used to demonstrate changes in the flux of fatty acids to the beta-oxidation cycle in transgenic plants and mutants affected in lipid biosynthesis, as well as to study the pathway of degradation of unusual fatty acids.

The clinical use of quantitative ultrasound (QUS) in the detection and management of osteoporosis

For the detection and management of osteoporosis and osteoporosis-related fractures, quantitative ultrasound (QUS) is emerging as a relatively low-cost and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) in certain circumstances. The following is a brief, but thorough review of the existing literature with respect to the use of QUS in 6 settings: 1) assessing fragility fracture risk; 2) diagnosing osteoporosis; 3) initiating osteoporosis treatment; 4) monitoring osteoporosis treatment; 5) osteoporosis case finding; and 6) quality assurance and control. Many QUS devices exist that are quite different with respect to the parameters they measure and the strength of empirical evidence supporting their use. In general, heel QUS appears to be most tested and most effective. Overall, some, but not all, heel QUS devices are effective assessing fracture risk in some, but not all, populations, the evidence being strongest for Caucasian females over 55 years old. Otherwise, the evidence is fair with respect to certain devices allowing for the accurate diagnosis of likelihood of osteoporosis, and generally fair to poor in terms of QUS use when initiating or monitoring osteoporosis treatment. A reasonable protocol is proposed herein for case-finding purposes, which relies on a combined assessment of clinical risk factors (CR.F) and heel QUS. Finally, several recommendations are made for quality assurance and control.

Cardiovascular Risk Prediction with Ultrasound

This paper addresses primary care physicians, cardiologists, internists, angiologists and doctors desirous of improving vascular risk prediction in primary care. Many cardiovascular risk factors act aggressively on the arterial wall and result in atherosclerosis and atherothrombosis. Cardiovascular prognosis derived from ultrasound imaging is, however, excellent in subjects without formation of intimal thickening or atheromas. Since ultrasound visualises the arterial wall directly, the information derived from the arterial wall may add independent incremental information to the knowledge of risk derived from global risk assessment. This paper provides an overview on plaque imaging for vascular risk prediction in two parts: Part 1: Carotid IMT is frequently used as a surrogate marker for outcome in intervention studies addressing rather large cohorts of subjects. Carotid IMT as a risk prediction tool for the prevention of acute myocardial infarction and stroke has been extensively studied in many patients since 1987, and has yielded incremental hazard ratios for these cardiovascular events independently of established cardiovascular risk factors. However, carotid IMT measurements are not used uniformly and therefore still lack widely accepted standardisation. Hence, at an individual, practicebased level, carotid IMT is not recommended as a risk assessment tool. The total plaque area of the carotid arteries (TPA) is a measure of the global plaque burden within both carotid arteries. It was recently shown in a large Norwegian cohort involving over 6000 subjects that TPA is a very good predictor for future myocardial infarction in women with an area under the curve (AUC) using a receiver operating curves (ROC) value of 0.73 (in men: 0.63). Further, the AUC for risk prediction is high both for vascular death in a vascular prevention clinic group (AUC 0.77) and fatal or nonfatal myocardial infarction in a true primary care group (AUC 0.79). Since TPA has acceptable reproducibility, allows calculation of posttest risk and is easily obtained at low cost, this risk assessment tool may come in for more widespread use in the future and also serve as a tool for atherosclerosis tracking and guidance for intensity of preventive therapy. However, more studies with TPA are needed. Part 2: Carotid and femoral plaque formation as detected by ultrasound offers a global view of the extent of atherosclerosis. Several prospective cohort studies have shown that cardiovascular risk prediction is greater for plaques than for carotid IMT. The number of arterial beds affected by significant atheromas may simply be added numerically to derive additional information on the risk of vascular events. A new atherosclerosis burden score (ABS) simply calculates the sum of carotid and femoral plaques encountered during ultrasound scanning. ABS correlates well and independently with the presence of coronary atherosclerosis and stenosis as measured by invasive coronary angiogram. However, the prognostic power of ABS as an independent marker of risk still needs to be elucidated in prospective studies. In summary, the large number of ways to measure atherosclerosis and related changes in human arteries by ultrasound indicates that this technology is not yet sufficiently perfected and needs more standardisation and workup on clearly defined outcome studies before it can be recommended as a practice-based additional risk modifier.

Non-viral ocular gene therapy: potential ocular therapeutic avenues.

Non-viral vectors for potential gene replacement and therapy have been developed in order to overcome the drawbacks of viral vectors. The diversity of non-viral vectors allows for a wide range of various products, flexibility of application, ease of use, low-cost of production and enhanced "genomic" safety. Using non-viral strategies, oligonucleotides (ODNs) can be delivered naked (less efficient) or entrapped in cationic lipids, polymers or peptides forming slow release delivery systems, which can be adapted according to the organ targeted and the therapy purposes. Tissue and cell internalization can be further enhanced by changing by physical or chemical means. Moreover, a specific vector can be selected according to disease course and intensity of manifestations fulfilling specific requirements such as the duration of drug release and its level along with cells and tissues specific targeting. From accumulating knowledge and experience, it appears that combination of several non-viral techniques may increase the efficacy and ensure the safety of these evolving and interesting gene therapy strategies.

Electrophysiological markers of rapid cognitive decline in mild cognitive impairment

Electroencephalography (EEG) is an easily accessible and low-cost modality that might prove to be a particularly powerful tool for the identification of subtle functional changes preceding structural or metabolic deficits in progressive mild cognitive impairment (PMCI). Most previous contributions in this field assessed quantitative EEG differences between healthy controls, MCI and Alzheimer's disease(AD) cases leading to contradictory data. In terms of MCI conversion to AD, certain longitudinal studies proposed various quantitative EEG parameters for an a priori distinction between PMCI and stable MCI. However, cross-sectional comparisons revealed a substantial overlap in these parameters between MCI patients and elderly controls. Methodological differences including variable clinical definition of MCI cases and substantial interindividual differences within the MCI group could partly explain these discrepancies. Most importantly, EEG measurements without cognitive demand in both cross-sectional and longitudinal designs have demonstrated limited sensitivity and generally do not produce significant group differences in spectral EEG parameters. Since the evolution of AD is characterized by the progressive loss of functional connectivity within neocortical association areas, event-modulated EEG dynamic analysis which makes it possible to investigate the functional activation of neocortical circuits may represent a more sensitive method to identify early alterations of neuronal networks predictive of AD development among MCI cases. The present review summarizes clinically significant results of EEG activation studies in this field and discusses future perspectives of research aiming to reach an early and individual prediction of cognitive decline in healthy elderly controls.

The double-edged sword of social capital: Three essays on entrepreneurship in developing nations

ABSTRACT My study seeks to answer the main question: "how does entrepreneurs' social capital positively and negatively affect their resource mobilization efforts, and exploitation of entrepreneurial opportunity?" To answer this question, I develop a model for examining positive and negative effects of social capital on resource accumulation by entrepreneurs, and the subsequent effect of resource accumulation on the exploitation of entrepreneurial opportunity, and utilize data from Africa to ëmpirically test the relationships in this model. Developing nations are a suitable context because: a) They require entrepreneurship for economic development, b) They have received less attention in management and entrepreneurship research, c) Because of inadequately-developed institutions, entrepreneurs from developing nations face major resource mobilization challenges hence they often turn to their social ties for resources, and d) The communalistic and collectivistic nature of most developing nations -encouraging support and sharing of resources- may help us better understand how society's values and structures may contribute and also deduct firm resources. My study reveals that social capital contributes resources to entrepreneurs in developing nations at a cost that takes away resources, and that more resources but lower costs facilitate entrepreneurial opportunity exploitation. For entrepreneurs in developing nations, large networks, greater shared identity, and more trust are beneficial. To increase chances of raising more resources, entrepreneurs from communalistic societies should include network members from outside their communities. Besides providing financial support, policy-makers should develop training programs and advisory services on configuration of entrepreneurs' networks so as to achieve more resources at a low cost. My study insights can help improve entrepreneurs' resource accumulation efforts and the subsequent growth of their firms, leading to the overall economic growth of developing nations.

How to Improve the Use of Proton Pump Inhibitors

Introduction: Proton pump inhibitors (PPI) are one of the most prescribed medications in the world with proven efficacy. However, several studies showed that their use often doesn't respect indications, leading to over-consumption, thus exposing patients to drug interactions and adverse events (for example pneumonias). Interruption of PPIs can induce a rebound phenomenon. This generates costs for health systems.Methods: This is a prospective interventional study performed in two hospitals: La Chaux-de-Fonds (CDF, cases) and Neucha^tel (NE, control) during two six-month periods, comparing use of PPIs before and after intervention. We elaborated recommendations (PPI doses and treatment duration) based on recent medical literature that we summarized on A6 cards and gave out to all prescribing doctors in the hospital of CDF and held a 30-minute information session for the departments of surgery, medicine and anesthesiology in March 2010. Doctors were asked to apply our recommendations as often as possible, leaving space for their own assessment. No information was given to the doctors of the control hospital. The number of PPI tablets that the pharmacy sent to each careunit in both hospitals was counted and adjusted to the number of patientdays from April to September 2009 (before intervention) and April to September 2010 (after intervention). The number of other antacids that were used in both hospitals was counted during the same periods. General practitioners (GP) in the region around CDF received an explanation letter to avoid re-introduction, after discharge from the hospital, of PPI treatment stopped during the stay. The number of gastro-duodenal ulcers and upper digestive hemorrhages was counted from April to December 2009 and the same period in 2010 in both hospitals.Results: In 2010, in the hospital of CDF, the use of PPIs per 100 patient-days decreased by 36% in the surgical and medical departments compared to 2009. In the control hospital the use of PPIs per 100 patient-days increased by 10% in the surgical department and decreased by 5% in the medical department during the same periods. The decrease from 2009 to 2010 of PPI utilization in CDF comparing to NE is statistically significant: p<0.0001. Use of other antacids didn't change, ulcers or digestive hemorrhages decreased slightly from 2009 to 2010 in both hospitals. Conclusions: The study showed that with a very low-cost intervention, it is possible to decrease considerably the use of PPIs in a hospital, without taking any risk for gastro-intestinal complications.

Medical record search engines, using pseudonymised patient identity: an alternative to centralised medical records

Purpose The purpose of our multidisciplinary study was to define a pragmatic and secure alternative to the creation of a national centralised medical record which could gather together the different parts of the medical record of a patient scattered in the different hospitals where he was hospitalised without any risk of breaching confidentiality. Methods We first analyse the reasons for the failure and the dangers of centralisation (i.e. difficulty to define a European patients' identifier, to reach a common standard for the contents of the medical record, for data protection) and then propose an alternative that uses the existing available data on the basis that setting up a safe though imperfect system could be better than continuing a quest for a mythical perfect information system that we have still not found after a search that has lasted two decades. Results We describe the functioning of Medical Record Search Engines (MRSEs), using pseudonymisation of patients' identity. The MRSE will be able to retrieve and to provide upon an MD's request all the available information concerning a patient who has been hospitalised in different hospitals without ever having access to the patient's identity. The drawback of this system is that the medical practitioner then has to read all of the information and to create his own synthesis and eventually to reject extra data. Conclusions Faced with the difficulties and the risks of setting up a centralised medical record system, a system that gathers all of the available information concerning a patient could be of great interest. This low-cost pragmatic alternative which could be developed quickly should be taken into consideration by health authorities.

Continuous positive airway pressure causes lung injury in a model of sepsis.

Continuous positive airway pressure, aimed at preventing pulmonary atelectasis, has been used for decades to reduce lung injury in critically ill patients. In neonatal practice, it is increasingly used worldwide as a primary form of respiratory support due to its low cost and because it reduces the need for endotracheal intubation and conventional mechanical ventilation. We studied the anesthetized in vivo rat and determined the optimal circuit design for delivery of continuous positive airway pressure. We investigated the effects of continuous positive airway pressure following lipopolysaccharide administration in the anesthetized rat. Whereas neither continuous positive airway pressure nor lipopolysaccharide alone caused lung injury, continuous positive airway pressure applied following intravenous lipopolysaccharide resulted in increased microvascular permeability, elevated cytokine protein and mRNA production, and impaired static compliance. A dose-response relationship was demonstrated whereby higher levels of continuous positive airway pressure (up to 6 cmH(2)O) caused greater lung injury. Lung injury was attenuated by pretreatment with dexamethasone. These data demonstrate that despite optimal circuit design, continuous positive airway pressure causes significant lung injury (proportional to the airway pressure) in the setting of circulating lipopolysaccharide. Although we would currently avoid direct extrapolation of these findings to clinical practice, we believe that in the context of increasing clinical use, these data are grounds for concern and warrant further investigation.

Essential surgery: the way forward.

INTRODUCTION: Very little surgical care is performed in low- and middle-income countries (LMICs). An estimated two billion people in the world have no access to essential surgical care, and non-surgeons perform much of the surgery in remote and rural areas. Surgical care is as yet not recognized as an integral aspect of primary health care despite its self-demonstrated cost-effectiveness. We aimed to define the parameters of a public health approach to provide surgical care to areas in most need. METHODS: Consensus meetings were held, field experience was collected via targeted interviews, and a literature review on the current state of essential surgical care provision in Sub-Saharan Africa (SSA) was conducted. Comparisons were made across international recommendations for essential surgical interventions and a consensus-driven list was drawn up according to their relative simplicity, resource requirement, and capacity to provide the highest impact in terms of averted mortality or disability. RESULTS: Essential Surgery consists of basic, low-cost surgical interventions, which save lives and prevent life-long disability or life-threatening complications and may be offered in any district hospital. Fifteen essential surgical interventions were deduced from various recommendations from international surgical bodies. Training in the realm of Essential Surgery is narrow and strict enough to be possible for non-physician clinicians (NPCs). This cadre is already active in many SSA countries in providing the bulk of surgical care. CONCLUSION: A basic package of essential surgical care interventions is imperative to provide structure for scaling up training and building essential health services in remote and rural areas of LMICs. NPCs, a health cadre predominant in SSA, require training, mentoring, and monitoring. The cost of such training is vastly more efficient than the expensive training of a few polyvalent or specialist surgeons, who will not be sufficient in numbers within the next few generations. Moreover, these practitioners are used to working in the districts and are much less prone to gravitate elsewhere. The use of these NPCs performing "Essential Surgery" is a feasible route to deal with the almost total lack of primary surgical care in LMICs.

Aortic blood pressure measured via EIT: investigation of different measurement settings.

Electrical impedance tomography (EIT) allows the measurement of intra-thoracic impedance changes related to cardiovascular activity. As a safe and low-cost imaging modality, EIT is an appealing candidate for non-invasive and continuous haemodynamic monitoring. EIT has recently been shown to allow the assessment of aortic blood pressure via the estimation of the aortic pulse arrival time (PAT). However, finding the aortic signal within EIT image sequences is a challenging task: the signal has a small amplitude and is difficult to locate due to the small size of the aorta and the inherent low spatial resolution of EIT. In order to most reliably detect the aortic signal, our objective was to understand the effect of EIT measurement settings (electrode belt placement, reconstruction algorithm). This paper investigates the influence of three transversal belt placements and two commonly-used difference reconstruction algorithms (Gauss-Newton and GREIT) on the measurement of aortic signals in view of aortic blood pressure estimation via EIT. A magnetic resonance imaging based three-dimensional finite element model of the haemodynamic bio-impedance properties of the human thorax was created. Two simulation experiments were performed with the aim to (1) evaluate the timing error in aortic PAT estimation and (2) quantify the strength of the aortic signal in each pixel of the EIT image sequences. Both experiments reveal better performance for images reconstructed with Gauss-Newton (with a noise figure of 0.5 or above) and a belt placement at the height of the heart or higher. According to the noise-free scenarios simulated, the uncertainty in the analysis of the aortic EIT signal is expected to induce blood pressure errors of at least ± 1.4 mmHg.

Development of an enantioselective assay for simultaneous separation of venlafaxine and O-desmethylvenlafaxine by micellar electrokinetic chromatography-tandem mass spectrometry: Application to the analysis of drug-drug interaction.

To-date, there has been no effective chiral capillary electrophoresis-mass spectrometry (CE-MS) method reported for the simultaneous enantioseparation of the antidepressant drug, venlafaxine (VX) and its structurally-similar major metabolite, O-desmethylvenlafaxine (O-DVX). This is mainly due to the difficulty of identifying MS compatible chiral selector, which could provide both high enantioselectivity and sensitive MS detection. In this work, poly-sodium N-undecenoyl-L,L-leucylalaninate (poly-L,L-SULA) was employed as a chiral selector after screening several dipeptide polymeric chiral surfactants. Baseline separation of both O-DVX and VX enantiomers was achieved in 15min after optimizing the buffer pH, poly-L,L-SULA concentration, nebulizer pressure and separation voltage. Calibration curves in spiked plasma (recoveries higher than 80%) were linear over the concentration range 150-5000ng/mL for both VX and O-DVX. The limit of detection (LOD) was found to be as low as 30ng/mL and 21ng/mL for O-DVX and VX, respectively. This method was successfully applied to measure the plasma concentrations of human volunteers receiving VX or O-DVX orally when co-administered without and with indinivar therapy. The results suggest that micellar electrokinetic chromatography electrospray ionization-tandem mass spectrometry (MEKC-ESI-MS/MS) is an effective low cost alternative technique for the pharmacokinetics and pharmacodynamics studies of both O-DVX and VX enantiomers. The technique has potential to identify drug-drug interaction involving VX and O-DVX enantiomers while administering indinivar therapy.

Development and evaluation of double locus sequence typing for molecular epidemiological investigations of Clostridium difficile.

Despite the development of novel typing methods based on whole genome sequencing, most laboratories still rely on classical molecular methods for outbreak investigation or surveillance. Reference methods for Clostridium difficile include ribotyping and pulsed-field gel electrophoresis, which are band-comparing methods often difficult to establish and which require reference strain collections. Here, we present the double locus sequence typing (DLST) scheme as a tool to analyse C. difficile isolates. Using a collection of clinical C. difficile isolates recovered during a 1-year period, we evaluated the performance of DLST and compared the results to multilocus sequence typing (MLST), a sequence-based method that has been used to study the structure of bacterial populations and highlight major clones. DLST had a higher discriminatory power compared to MLST (Simpson's index of diversity of 0.979 versus 0.965) and successfully identified all isolates of the study (100 % typeability). Previous studies showed that the discriminatory power of ribotyping was comparable to that of MLST; thus, DLST might be more discriminatory than ribotyping. DLST is easy to establish and provides several advantages, including absence of DNA extraction [polymerase chain reaction (PCR) is performed on colonies], no specific instrumentation, low cost and unambiguous definition of types. Moreover, the implementation of a DLST typing scheme on an Internet database, such as that previously done for Staphylococcus aureus and Pseudomonas aeruginosa ( http://www.dlst.org ), will allow users to easily obtain the DLST type by submitting directly sequencing files and will avoid problems associated with multiple databases.

Educational resources offered by the European Board of Physical and Rehabilitation Medicine (EBPRM)

Background .- Physical and Rehabilitation Medicine (PRM) is a very demanding medical speciality. To ensure high standard of research and care in PRM all across Europe, it is crucial to attract gifted trainees and offer them high quality education. At undergraduate level, many medical schools in Europe omit to offer teaching on disabled persons and on basic PRM knowledge. Thus PRM is hardly known to medical students. For postgraduate trainees access to evidence-based knowledge as well as teaching of research methodology specific to PRM, rehabilitation methodology, disability management and team building also need to be strengthened to increase the visibility of PRM. Action .- To address these issues the EBPRM proposes presently a specific undergraduate curriculum in PRM including the issues of disability, participation and handicap as a basis for general medical practice and postgraduate rehabilitation training. For PRM trainees many educational documents are now available on the EBPRM website. A growing number of educational sessions for PRM trainees take place during international and national PRM Congresses which can be accessed at low cost. Educational papers published regularly in European rehabilitation journals and European PRM Schools are offered free or at very low cost to trainees.

Improving the molecular diagnosis of Chlamydia psittaci and Chlamydia abortus infection with a species-specific duplex real-time PCR.

Chlamydia psittaci and Chlamydia abortus are closely related intracellular bacteria exhibiting different tissue tropism that may cause severe but distinct infection in humans. C. psittaci causes psittacosis, a respiratory zoonotic infection transmitted by birds. C. abortus is an abortigenic agent in small ruminants, which can also colonize the human placenta and lead to foetal death and miscarriage. Infections caused by C. psittaci and C. abortus are underestimated mainly due to diagnosis difficulties resulting from their strict intracellular growth. We developed a duplex real-time PCR to detect and distinguish these two bacteria in clinical samples. The first PCR (PCR1) targeted a sequence of the 16S-23S rRNA operon allowing the detection of both C. psittaci and C. abortus. The second PCR (PCR2) targeted the coding DNA sequence CPSIT_0607 unique to C. psittaci. The two PCRs showed 100 % detection for ≥ 10 DNA copies per reaction (1000 copies ml- 1). Using a set of 120 samples, including bacterial reference strains, clinical specimens and infected cell culture material, we monitored 100 % sensitivity and 100 % specificity for the detection of C. psittaci and C. abortus for PCR1. When PCR1 was positive, PCR2 could discriminate C. psittaci from C. abortus with a positive predictive value of 100 % and a negative predictive value of 88 %. In conclusion, this new duplex PCR represents a low-cost and time-saving method with high-throughput potential, expected to improve the routine diagnosis of psittacosis and pregnancy complication in large-scale screening programs and also during outbreaks.