Protein-binding microarrays: probing disease markers at the interface of proteomics and genomics.

DNA-binding proteins mediate a variety of crucial molecular functions, such as transcriptional regulation and chromosome maintenance, replication and repair, which in turn control cell division and differentiation. The roles of these proteins in disease are currently being investigated using microarray-based approaches. However, these assays can be difficult to adapt to routine diagnosis of complex diseases such as cancer. Here, we review promising alternative approaches involving protein-binding microarrays (PBMs) that probe the interaction of proteins from crude cell or tissue extracts with large collections of synthetic or natural DNA sequences. Recent studies have demonstrated the use of these novel PBM approaches to provide rapid and unbiased characterization of DNA-binding proteins as molecular markers of disease, for example cancer progression or infectious diseases.

Real-time motion correction in navigator-gated free-breathing double-oblique submillimeter 3D right coronary artery magnetic resonance angiography.

RATIONALE AND OBJECTIVES: The purpose of this study was the investigation of the impact of real-time adaptive motion correction on image quality in navigator-gated, free-breathing, double-oblique three-dimensional (3D) submillimeter right coronary magnetic resonance angiography (MRA). MATERIALS AND METHODS: Free-breathing 3D right coronary MRA with real-time navigator technology was performed in 10 healthy adult subjects with an in-plane spatial resolution of 700 x 700 microm. Identical double-oblique coronary MR-angiograms were performed with navigator gating alone and combined navigator gating and real-time adaptive motion correction. Quantitative objective parameters of contrast-to-noise ratio (CNR) and vessel sharpness and subjective image quality scores were compared. RESULTS: Superior vessel sharpness, increased CNR, and superior image quality scores were found with combined navigator gating and real-time adaptive motion correction (vs. navigator gating alone; P < 0.01 for all comparisons). CONCLUSION: Real-time adaptive motion correction objectively and subjectively improves image quality in 3D navigator-gated free-breathing double-oblique submillimeter right coronary MRA.

Analysis of bioavailable arsenic in rice with whole cell living bioreporter bacteria.

A multiwell plate bioassay was developed using genetically modified bacteria (bioreporter cells) to detect inorganic arsenic extracted from rice. The bacterial cells expressed luciferase upon exposure to arsenite, the activity of which was detected by measurement of cellular bioluminescence. The bioreporter cells detected arsenic in all rice varieties tested, with averages of 0.02-0.15 microg of arsenite equivalent per gram of dry weight and a method detection limit of 6 ng of arsenite per gram of dry rice. This amounted to between approximately 20 and 90% of the total As content reported by chemical methods for the same sample and suggested that a major proportion of arsenic in rice is in the inorganic form. Calibrations of the bioassay with pure inorganic and organic arsenic forms showed that the bacterial cells react to arsenite with highest affinity, followed by arsenate (with 25% response relative to an equivalent arsenite concentration) and trimethylarsine oxide (at 10% relative response). A method for biocompatible arsenic extraction was elaborated, which most optimally consisted of (i) grinding rice to powder, (ii) mixing with an aqueous solution containing pancreatic enzymes, (iii) mechanical shearing, (iv) extraction in mild acid conditions and moderate heat, and (v) centrifugation and pH neutralization. Detection of mainly inorganic arsenic by the bacterial cells may have important advantages for toxicity assessment of rice consumption and would form a good complement to total chemical arsenic determination.

Consequences of one-week creatine supplementation on creatine and creatinine levels in athletes 'serum and urine

We explored the washout period of creatine (Cr) after repeated ingestions of high doses of exogenous Cr. Ten athletes ingested daily, in a randomized double-blind study design, 30 g of exoge- nous Cr (n = 5, Cr-group) or a placebo (n = 5, Pl-group). Serum and urine samples were collected 1) before supplementation (BEFO- RE), 2) after one week Cr supplementation (AFTER), and 3) one week later without supplementation (LATER). The Cr and crea- tinine (Crn) concentrations in serum (sCr, sCrn) and in multiple spots urine (uCr, uCrn) were measured. We observed a significant rise (p < 0.01) in sCr, uCr and sCrn between BEFORE and AFTER supplementation in Cr-group, as well as a significant difference between Cr-group and Pl-group. Body weight increased signifi- cantly (+1.5 kg), but relative body fat (%fat) was unchanged. After the washout period in LATER Cr-group, sCr and uCr decreased to low residual values. No loss of body weight occurred during thisperiod. In contrast, sCrn and uCrn returned to baseline values. In conclusion, regular uptake of high doses of exogenous Cr affects both Cr and Crn concentrations in serum (sCr: 14 folds; sCrn: 1.2 folds) and urine (uCr: 140 folds; uCrn: 1.5 folds). An abuse of Cr is therefore mostly spilled over in urine. Surprise drug tests, such as doping controls, happening during the period of Cr supplementa- tion can reveal an important increase in Cr and Crn concentrations, although subjects stopped suddenly Cr loading. The discernible effect of Cr supplementation on these values disappeared within one week.

Inhibitory effect of DNA supercoiling on DNA knotting

Using numerical simulations we investigated the effect of DNA supercoiling on the topological equilibrium of DNA molecules. We showed that under the steady state conditions that maintain the same effective deficit of the linking number in unknotted and knotted DNA molecules the topological equilibrium results in a much smaller fraction of knots than in the case of torsionally relaxed DNA molecules. Based on these results we propose that one of the important functions of DNA supercoiling is to reduce formation of DNA knots.

Energy balance, physical activity, and thermogenic effect of feeding in premature infants.

In order to assess the contribution of the thermogenic effect of feeding and muscular activity to total energy expenditure, nine premature infants were studied for 2 consecutive days during which time repeated measurements of energy expenditure by indirect calorimetry were performed throughout the day, combined with a visual activity score based on body movement. The infants were growing at 16.6 +/- 4.0 g/kg/day (mean +/- SD) and received 110 +/- 8 kcal/kg/day metabolizable energy (milk formula) and 522 +/- 40 mgN/kg/day. Their total energy expenditure was 68 +/- 4 kcal/kg/day indicating that 41 +/- 7 kcal/kg/day was retained for growth. Based on the combination of energy + N balances it was estimated that 80% of the weight gain was fat-free tissue and 20% was fat tissue. The rate of energy expenditure measured minute-by-minute was significantly and linearly correlated with the activity score in both the premeal (r = 0.75;p less than 0.001) and the postmeal periods (r = 0.74; p less than 0.001) with no difference in the regression slope, but with a significant difference in intercept. In preset feeding schedules the latter allowed an estimation of the thermogenic effect without the confounding effect of activity. This was found to be 3.1 +/- 1.8% when expressed as a percentage of metabolizable energy intake. However when the "classical" approach was used as a comparison (integration of extra energy expenditure induced by the meal), the thermogenic effect was found to be greater, i.e. 9.5 +/- 3.8% of the meal's metabolizable energy, due to the superimposed effect of physical activity in the postprandial state.(ABSTRACT TRUNCATED AT 250 WORDS)

Limites des procédés d'investigation de la fonction érectile dans le cadre d'expertises médicolégales [Limits of the processes of investigation of the erectile function in forensic expertises].

Résumé La responsabilité d'un expert chargé d'apprécier la capacité érectile d'un prévenu est importante, car la peine infligée par le tribunal peut dépendre de ses conclusions. Sa tâche est en plus ardue car les procédés d'investigations de la fonction érectile ont tous des limites. Malgré toutes ces limites qui sont décrites dans cet article, l'expert peut aider à la recherche de la vérité comme les auteurs le démontrent. Summary The responsability of the expert in charge to appreciate the erectile capacity of an accused is considerable, as the sentence inflicted by the Tribunal could depend directly on his conclusions. His duty is harder as all the investigation procedures of the erectile functions have limits. Despite these limits, described in this article, the expert can help to discover the truth, as demonstrated by the authors.

Altered decision-making in multiple sclerosis: a sign of impaired emotional reactivity?

We assessed decision-making capacity and emotional reactivity in 20 patients with multiple sclerosis (MS) and in 16 healthy subjects using the Gambling Task (GT), a model of real-life decision making, and the skin conductance response (SCR). Demographic, neurological, affective, and cognitive parameters were analyzed in MS patients for their effect on decision-making performance. MS patients persisted longer (slope, -3.6%) than the comparison group (slope, -6.4%) in making disadvantageous choices as the GT progressed (p < 0.001), suggesting significant slower learning in MS. Patients with higher Expanded Disability Status Scale scores (EDSS >2.0) showed a different pattern of impairment in the learning process compared with patients with lower functional impairment (EDSS </=2.0). This slower learning was associated with impaired emotional reactivity (anticipatory SCR 3.9 vs 6.1 microSiemens [microS] for patients vs the comparison group, p < 0.0001; post-choice SCR 3.9 vs 6.2 microS, p < 0.0001), but not with executive dysfunction. Impaired emotional dimensions of behavior (assessed using the Dysexecutive Questionnaire, p < 0.002) also correlated with slower learning. Given the considerable consequences that impaired decision making can have on daily life, we suggest that this factor may contribute to handicap and altered quality of life secondary to MS and is dependent on emotional experience. Ann Neurol 2004.

Stochastic models and numerical algorithms for a class of regulatory gene networks.

Regulatory gene networks contain generic modules, like those involving feedback loops, which are essential for the regulation of many biological functions (Guido et al. in Nature 439:856-860, 2006). We consider a class of self-regulated genes which are the building blocks of many regulatory gene networks, and study the steady-state distribution of the associated Gillespie algorithm by providing efficient numerical algorithms. We also study a regulatory gene network of interest in gene therapy, using mean-field models with time delays. Convergence of the related time-nonhomogeneous Markov chain is established for a class of linear catalytic networks with feedback loops.

On-line desorption of dried blood spot: A novel approach for the direct LC/MS analysis of micro-whole blood samples.

The aim of this work is to present a new concept, called on-line desorption of dried blood spots (on-line DBS), allowing the direct analysis of a dried blood spot coupled to liquid chromatography mass spectrometry device (LC/MS). The system is based on an inox cell which can receive a blood sample (10 microL) previously spotted on a filter paper. The cell is then integrated into LC/MS system where the analytes are desorbed out of the paper towards a column switching system ensuring the purification and separation of the compounds before their detection on a single quadrupole MS coupled to atmospheric pressure chemical ionisation (APCI) source. The described procedure implies that no pretreatment is necessary in spite the analysis is based on whole blood sample. To ensure the applicability of the concept, saquinavir, imipramine, and verapamil were chosen. Despite the use of a small sampling volume and a single quadrupole detector, on-line DBS allowed the analyses of these three compounds over their therapeutic concentrations from 50 to 500 ng/mL for imipramine and verapamil and from 100 to 1000 ng/mL for saquinavir. Moreover, the method showed good repeatability with relative standard deviation (RSD) lower than 15% based on two levels of concentration (low and high). Function responses were found to be linear over the therapeutic concentration for each compound and were used to determine the concentrations of real patient samples for saquinavir. Comparison of the founded values with those of a validated method used routinely in a reference laboratory showed a good correlation between the two methods. Moreover, good selectivity was observed ensuring that no endogenous or chemical components interfered with the quantitation of the analytes. This work demonstrates the feasibility and applicability of the on-line DBS procedure for bioanalysis.

Circadian regulation of renal function and potential role in hypertension.

PURPOSE OF REVIEW: Previous studies have shown that a variety of specific renal functions exhibit circadian oscillations. This review aims to provide an update on the molecular mechanisms underlying circadian rhythms in the kidney, and to discuss how dysregulation of circadian rhythms can interfere with kidney function. RECENT FINDINGS: The molecular mechanism responsible for generating and maintaining circadian rhythms has been unraveled in great detail. This mechanism, known as the circadian clock, drives circadian oscillation in expression levels of a large number of renal mRNA transcripts. Several proteins critically involved in renal homeostatic functions have been shown to exhibit significant circadian oscillation in their expression levels or in their posttranslational modifications. In transgenic mouse models, disruption of circadian clock activity results in dramatic changes in the circadian pattern of urinary sodium and potassium excretion and causes significant changes in arterial blood pressure. A growing amount of evidence suggests that dysregulation of circadian rhythms is associated with the development of hypertension and accelerated progression of chronic kidney disease and cardiovascular disease in humans. Chronotherapy studies have shown that the efficacy of antihypertensive medication is greatly dependent on the circadian time of drug administration. SUMMARY: Recent research points to the major role of circadian rhythms in renal function and in control of blood pressure.

Transcranial direct current stimulation for the treatment of focal hand dystonia.

The treatment of writer's cramp, a task-specific focal hand dystonia, needs new approaches. A deficiency of inhibition in the motor cortex might cause writer's cramp. Transcranial direct current stimulation modulates cortical excitability and may provide a therapeutic alternative. In this randomized, double-blind, sham-controlled study, we investigated the efficacy of cathodal stimulation of the contralateral motor cortex in 3 sessions in 1 week. Assessment over a 2-week period included clinical scales, subjective ratings, kinematic handwriting analysis, and neurophysiological evaluation. Twelve patients with unilateral dystonic writer's cramp were investigated; 6 received transcranial direct current and 6 sham stimulation. Cathodal transcranial direct current stimulation had no favorable effects on clinical scales and failed to restore normal handwriting kinematics and cortical inhibition. Subjective worsening remained unexplained, leading to premature study termination. Repeated sessions of cathodal transcranial direct current stimulation of the motor cortex yielded no favorable results supporting a therapeutic potential in writer's cramp.

Epidemiology of cleft palate in Europe: implications for genetic research.

OBJECTIVE: To describe the epidemiology of cleft palate (CP) in Europe. DESIGN AND SETTING: A descriptive epidemiological study on 3852 cases of CP, identified (1980 through 1996) from more than 6 million births from the EUROCAT network of 30 registers in 16 European countries. RESULTS: Significant differences in prevalence in Europe between registries and within countries were observed. A total of 2112 (54.8%) CP cases occurred as isolated, 694 (18.0%) were associated with other defects such as multiple congenital anomalies, and 1046 (27.2%) were in recognized conditions. The study confirmed the tendency toward female prevalence (sex ratio [SR] = 0.83), particularly among isolated cases (SR = 0.78) even if SR inversion is reported in some registries. A specific association with neural tube defects (NTDs) in some registers is reported. CONCLUSION: The differences identified in Europe (prevalence, sex, associated anomalies) can be only partially explained by methodological reasons because a common methodology was shared among all registries for case ascertainment and collection, and CP is an easy detectable condition with few induced abortions. The complex model of inheritance and the frequently conflicting results in different populations on the role of genes that constitute risk factors suggest the presence of real biological differences. The association of CP/NTD in an area with a high prevalence of NTDs can identify a group of conditions that can be considered etiologically homogeneous. The epidemiological evaluation can guide genetic research to specify the role of etiological factors in each different population

Preserving the health of ambulance personnel : some preliminary results from a study of pre-hospital emergency interventions

Little is known about the health of ambulance personnel, especially in Switzerland. This lack of knowledge is particularly striking in the specific field of occupational health. This study aims to identify and better understand protective and risk factors affecting the health of ambulance personnel. Both mental and physical health are considered. The approach used comprised two steps. The first step began in July 2008 and consisted in a qualitative study of real work activities performed by ambulance crews involved in pre-hospital emergency interventions. Researchers shadowed ambulance personnel for the duration of their entire work shift, in average for one week. The paper-pen technique was used to note dialogues, interactions, postural aspects, etc. When the situation allowed it, interventions were filmed. Some selected video sequences were used as a support for selfconfrontation interviews. Observations were performed by three researchers and took place in eleven services, for a total of 416 hours of observations (including 72 interventions + waiting time). Analysis, conducted by a multidisciplinary team (an ergonomist, an occupational therapist and a health psychologist), focused on individual and collective strategies used by ambulance personnel to protect their health. The second step, which is currently ongoing, aims to assess global health of ambulance personnel. A questionnaire is used to gather information about musculoskeletal complaints (Nordic questionnaire), mental health (GHQ-12), stress (Effort-Reward imbalance questionnaire), strategies implemented to cope with stress (Brief COPE), and working conditions. Specific items on strategies were developed based on observational data. It will be sent to all ambulance personnel employed in the French-speaking part of Switzerland. Preliminary analyses show different types of strategies used by ambulance personnel to preserve their health. These strategies involve postural aspects (e.g. use doorframe as a support to ease delicate manipulations), work environment adaptations (e.g. move furniture to avoid awkward postures), coping strategies (e.g. humor), as well as organisational (e.g. formal and informal debriefing) and collective (e.g. cooperation) mechanisms. In-depth analysis is still ongoing. However, patient safety and comfort, work environment and available resources appear to influence the choice of strategies ambulance personnel use. As far as possible, the strategies identified will be transformed into educational materials for professional ambulance personnel.

Syndrome hypothénarien du marteau: étiologie peu connue de phénomène de Raynaud secondaire [Hypothenar hammer syndrome: little-known etiology of secondary Raynaud's phenomenon]

Hypothenar hammer syndrome is an uncommonly encountered cause of Raynaud's phenomenon associated with professional or recreational activities. We report 6 consecutive cases seen in our angiology unit between 1988 and 1990. Clinical findings include a history of repeated microtraumatisms of the dominant hand, male sex, unilaterality, sudden onset, and severe Raynaud's phenomenon of the last three fingers. Investigations reveal an aneurysm or thrombosis of the distal cubital artery or of the superficial palmar branch, associated with occlusion of digital arteries. Avoidance of the aggravating conditions or resection and/or plasty of the affected vascular segment usually leads to disappearance of the symptoms.