Weed or wheel! FMRI, behavioural, and toxicological investigations of how cannabis smoking affects skills necessary for driving.

Marijuana is the most widely used illicit drug, however its effects on cognitive functions underling safe driving remain mostly unexplored. Our goal was to evaluate the impact of cannabis on the driving ability of occasional smokers, by investigating changes in the brain network involved in a tracking task. The subject characteristics, the percentage of Δ(9)-Tetrahydrocannabinol in the joint, and the inhaled dose were in accordance with real-life conditions. Thirty-one male volunteers were enrolled in this study that includes clinical and toxicological aspects together with functional magnetic resonance imaging of the brain and measurements of psychomotor skills. The fMRI paradigm was based on a visuo-motor tracking task, alternating active tracking blocks with passive tracking viewing and rest condition. We show that cannabis smoking, even at low Δ(9)-Tetrahydrocannabinol blood concentrations, decreases psychomotor skills and alters the activity of the brain networks involved in cognition. The relative decrease of Blood Oxygen Level Dependent response (BOLD) after cannabis smoking in the anterior insula, dorsomedial thalamus, and striatum compared to placebo smoking suggests an alteration of the network involved in saliency detection. In addition, the decrease of BOLD response in the right superior parietal cortex and in the dorsolateral prefrontal cortex indicates the involvement of the Control Executive network known to operate once the saliencies are identified. Furthermore, cannabis increases activity in the rostral anterior cingulate cortex and ventromedial prefrontal cortices, suggesting an increase in self-oriented mental activity. Subjects are more attracted by intrapersonal stimuli ("self") and fail to attend to task performance, leading to an insufficient allocation of task-oriented resources and to sub-optimal performance. These effects correlate with the subjective feeling of confusion rather than with the blood level of Δ(9)-Tetrahydrocannabinol. These findings bolster the zero-tolerance policy adopted in several countries that prohibits the presence of any amount of drugs in blood while driving.

Self-perception of aging and vulnerability to adverse outcomes at the age of 65-70 years.

OBJECTIVES. This study examines the relationship between self-perception of aging and vulnerability to adverse outcomes in adults aged 65-70 years using data from a cohort of 1,422 participants in Lausanne, Switzerland. METHODS: A positive or negative score of perception of aging was established using the Attitudes Toward Own Aging subscale including 5 items of the Philadelphia Geriatric Center Morale Scale. Falls, hospitalizations, and difficulties in basic and instrumental activities of daily living (ADL) collected in the first 3 years of follow-up were considered adverse outcomes. The relationship between perception and outcomes were evaluated using multiple logistic regression models adjusting for chronic medical conditions, depressive feelings, living arrangement, and socioeconomic characteristics. RESULTS: The strongest associations of self-perception of aging with outcomes were observed for basic and instrumental ADL. Associations with falls and hospitalizations were not constant but could be explained by health characteristics. CONCLUSIONS: A negative self-perception of aging is an indicator of risk for future disability in ADL. Factors such as a low-economic status, living alone, multiple chronic medical conditions, and depressive feelings contribute to a negative self-perception of aging but do not explain the relationship with incident activities of daily living disability.

Investigation of classical epidemiological links between patients harbouring identical, non-predominant meticillin-resistant Staphylococcus aureus genotypes and lessons for epidemiological tracking.

According to molecular epidemiology theory, two isolates belong to the same chain of transmission if they are similar according to a highly discriminatory molecular typing method. This has been demonstrated in outbreaks, but is rarely studied in endemic situations. Person-to-person transmission cannot be established when isolates of meticillin-resistant Staphylococcus aureus (MRSA) belong to endemically predominant genotypes. By contrast, isolates of infrequent genotypes might be more suitable for epidemiological tracking. The objective of the present study was to determine, in newly identified patients harbouring non-predominant MRSA genotypes, whether putative epidemiological links inferred from molecular typing could replace classical epidemiology in the context of a regional surveillance programme. MRSA genotypes were defined using double-locus sequence typing (DLST) combining clfB and spa genes. A total of 1,268 non-repetitive MRSA isolates recovered between 2005 and 2006 in Western Switzerland were typed: 897 isolates (71%) belonged to four predominant genotypes, 231 (18%) to 55 non-predominant genotypes, and 140 (11%) were unique. Obvious epidemiological links were found in only 106/231 (46%) patients carrying isolates with non-predominant genotypes suggesting that molecular surveillance identified twice as many clusters as those that may have been suspected with classical epidemiological links. However, not all of these molecular clusters represented person-to-person transmission. Thus, molecular typing cannot replace classical epidemiology but is complementary. A prospective surveillance of MRSA genotypes could help to target epidemiological tracking in order to recognise new risk factors in hospital and community settings, or emergence of new epidemic clones.

Do Objective Measures of Blood Alcohol Concentrations Make More Sense than Self-reports in Emergency Department Studies?

Purpose: Concerns about self-reports have led to calls for objective measures of blood alcohol concentration (BAC). The present study compared objective measures with self-reports. Methods: BAC from breath or blood samples were obtained from 272 randomly sampled injured patients who were admitted to a Swiss emergency department (ED). Self-reports were compared a) between those providing and refusing a BAC test, and b) to estimated peak BAC (EPBAC) values based on BACs using the Widmark formula. Results: Those providing BACs were significantly (P < 0.05) younger, more often male, and less often reported alcohol consumption before injury, but consumed higher quantities when drinking. Eighty-eight percent of those with BAC measures gave consistent reports (positive or negative). Significantly more patients reported consumption with negative BAC measures (N = 29) than vice versa (N = 3). Duration of consumption and times between injury and BAC measurement predicted EPBAC better than did the objective BAC measure. Conclusions: There is little evidence that patients who provide objective BAC measures deliberately conceal consumption. ED studies must rely on self-reports, eg, take the time period between injury and ED admission into account. Clearly, objective measures are of clinical relevance, eg, to provide optimal treatment in the ED. However, they may be less relevant to establishing effects in an epidemiologic sense, such as estimating risk relationships. In this respect, efforts to increase the validity and reliability of self-reports should be preferred over the collection of additional objective measures.

Real-time MR imaging of myocardial regional function using strain-encoding (SENC) with tissue through-plane motion tracking.

PURPOSE: To implement real-time myocardial strain-encoding (SENC) imaging in combination with tracking the tissue displacement in the through-plane direction. MATERIALS AND METHODS: SENC imaging was combined with the slice-following technique by implementing three-dimensional (3D) selective excitation. Certain adjustments were implemented to reduce scan time to one heartbeat. A total of 10 volunteers and five pigs were scanned on a 3T MRI scanner. Spatial modulation of magnetization (SPAMM)-tagged images were acquired on planes orthogonal to the SENC planes for comparison. Myocardial infarction (MI) was induced in two pigs and the resulting SENC images were compared to standard delayed-enhancement (DE) images. RESULTS: The strain values computed from SENC imaging with slice-following showed significant difference from those acquired without slice-following, especially during systole (P < 0.01). The strain curves computed from the SENC images with and without slice-following were similar to those computed from the orthogonal SPAMM images, with and without, respectively, tracking the tag line displacement in the strain direction. The resulting SENC images showed good agreement with the DE images in identifying MI in infarcted pigs. CONCLUSION: Correction of through-plane motion in real-time cardiac functional imaging is feasible using slice-following. The strain measurements are more accurate than conventional SENC measurements in humans and animals, as validated with conventional MRI tagging.

Vessel centerline tracking and boundary sgementation in coronary MRA with minimal manual interaction.

Magnetic resonance angiography (MRA) provides a noninvasive means to detect the presence, location and severity of atherosclerosis throughout the vascular system. In such studies, and especially those in the coronary arteries, the vessel luminal area is typically measured at multiple cross-sectional locations along the course of the artery. The advent of fast volumetric imaging techniques covering proximal to mid segments of coronary arteries necessitates automatic analysis tools requiring minimal manual interactions to robustly measure cross-sectional area along the three-dimensional track of the arteries in under-sampled and non-isotropic datasets. In this work, we present a modular approach based on level set methods to track the vessel centerline, segment the vessel boundaries, and measure transversal area using two user-selected endpoints in each coronary of interest. Arterial area and vessel length are measured using our method and compared to the standard Soap-Bubble reformatting and analysis tool in in-vivo non-contrast enhanced coronary MRA images.

Efficient self-synchronised blind audio watermarking system based on time domain and FFT amplitude modification

Many audio watermarking schemes divide the audio signal into several blocks such that part of the watermark is embedded into each of them. One of the key issues in these block-oriented watermarking schemes is to preserve the synchronisation, i.e. to recover the exact position of each block in the mark recovery process. In this paper, a novel time domain synchronisation technique is presented together with a new blind watermarking scheme which works in the Discrete Fourier Transform (DFT or FFT) domain. The combined scheme provides excellent imperceptibility results whilst achieving robustness against typical attacks. Furthermore, the execution of the scheme is fast enough to be used in real-time applications. The excellent transparency of the embedding algorithm makes it particularly useful for professional applications, such as the embedding of monitoring information in broadcast signals. The scheme is also compared with some recent results of the literature.

Superior flow for bridge to life with self-expanding venous cannulas.

BACKGROUND: Recently, a compact cardiopulmonary support (CPS) system designed for quick set-up for example, during emergency cannulation, has been introduced. Traditional rectilinear percutaneous cannulas are standard for remote vascular access with the original design. The present study was designed to assess the potential of performance increase by the introduction of next-generation, self-expanding venous cannulas, which can take advantage of the luminal width of the venous vasculature despite a relatively small access orifice. METHODS: Veno-arterial bypass was established in three bovine experiments (69+/-10 kg). The Lifebridge (Lifebridge GmbH, Munich, Germany) system was connected to the right atrium in a trans-jugular fashion with various venous cannulas; and the oxygenated blood was returned through the carotid artery with a 17 F percutaneous cannula. Two different venous cannulas were studied, and the correlation between the centrifugal pump speed (1500-3900 RPM), flow and the required negative pressure on the venous side was established: (A) Biomedicus 19 F (Medtronic, Tolochenaz, Switzerland); (B) Smart canula 18 F/36 F (Smartcanula LLC, Lausanne, Switzerland). RESULTS: At 1500 RPM, the blood flow was 0.44+/-0.26 l min(-1) for the 19 F rectilinear cannula versus 0.73+/-0.34 l min(-1) for the 18/36 F self-expanding cannula. At 2500 RPM the blood flow was 1.63+/-0.62 l min(-1) for the 19F rectilinear cannula versus 2.13+/-0.34 l min(-1) for the 18/36 F self-expanding cannula. At 3500 RPM, the blood flow was 2.78+/-0.47 l min(-1) for the 19 F rectilinear cannula versus 3.64+/-0.39 l min(-1) for the 18/36 F self-expanding cannula (p<0.01 for 18/36 F vs 19 F). At 1500 RPM, the venous line pressure was 18+/-8 mmHg for the 19F rectilinear cannula versus 19+/-5 mmHg for the 18/36 F self-expanding cannula. At 2500 RPM the venous line pressure accounted for -22+/-32 mmHg for the 19 F rectilinear cannula versus 2+/-5 mmHg for the 18/36 F self-expanding cannula. At 3500 RPM, the venous line pressure was -112+/-42 mmHg for the rectilinear cannula versus 28+/-7 mmHg for the 18/36 F self-expanding cannula (p<0.01 for 18 F/36 F vs 19 F). Conclusions: The negative pressure required to achieve adequate venous drainage with the self-expanding venous cannula accounts for approximately 31% of the pressure necessary with the 19 F rectilinear cannula. In addition, a pump flow of more than 4 l min(-1) can be achieved with the self-expanding design and a well-accepted negative inlet pressure for minimal blood trauma of less than 50 mmHg.

Quette place pour l'automesure glycémique dans la prise en charge du diabète de type 2 [Which role for self-monitoring of blood glucose in type 2 diabetes?]

There is a sustained controversy in the literature about the role and utility of self-monitoring of blood glucose (SMBG) in type 2 diabetes. The study results in this field do not provide really useful clues for the integration of SMBG in the follow-up of the individual patient, because they are based on a misconception of SMBG. It is studied as if it was a medical treatment whose effect on glycemic control is to be isolated. However, SMBG has no such intrinsic effect. It gains its purpose only as an inseparable component of a comprehensive and structured educational strategy. To be appropriate this strategy cannot be based on the health care professionals' view on diabetes only. It rather has to be tailored to the individual patient's needs through an ongoing process of shared reflection with him.

The Child Occupational Self Assessment (COSA, version 2.1) : lasten toimintamahdollisuuksien itsearviointi COSA:n esittely ja suomentamisprosessi

Tämän opinnäytetyön tarkoituksena on aloittaa lapsille ja nuorille suunnatun The Child Occupational Self Assessment (COSA, version 2.1) itsearviointimenetelmän suomenkielisen version käännöstyö. COSA on asiakaslähtöinen itsearviointi, jolla kartoitetaan lasten ja nuorten kokemusta toiminnallisesta pätevyydestään ja jokapäiväisten toimintojen tärkeydestä heille. COSA pohjaa Inhimillisen toiminnan malliin ja sen toteutus seuraa asiakaslähtöistä teoriaa. COSA:n avulla voidaan asettaa toimintaterapialle tavoitteet ja tarkastella niiden toteutumista. Työssämme suomennamme arviointimenetelmän nimen muotoon; Lasten toimintamahdollisuuksien itsearviointi COSA. Arviointimenetelmän käännöstyö tehdään Helsingin ammattikorkeakoulu Stadian toimintaterapian koulutusohjelmalle. Opinnäytetyössä esittelemme ensin arviointia ja tavoitteiden asettamista lasten toimintaterapiassa sekä itsearvioinnin käyttämistä arviointimenetelmänä. Esittelemme COSA itsearviointimenetelmän sekä sen taustalla vaikuttavat Inhimillisen toiminnan mallin sisällön ja asiakaslähtöisyyden. Kartoitamme myös The Child Occupational Self Assessment (COSA, version 2.1 )itsearviointimenetelmän kehittymistä, sitä edeltäneitä arviointimenetelmiä ja COSA:sta aiemmin tehtyjä tutkimuksia. Opinnäytetyössä suomennamme COSA:n arviointilomakkeen. Arviointilomakkeessa on 25 lasten ja nuorten toiminnallista pätevyyttä ja jokapäiväisten toimintojen tärkeyttä kartoittava väittämää. Suomentamisprosessissa selvitämme COSA:n arviointilomakkeen väittämien suomennosten ymmärrettävyyden onnistumista kahdeksan käyttökokeiluun ja haastatteluun osallistuvan lapsen avulla. Saimme arviointilomakkeen suomentamisprosessiin apua neljältä lasten kanssa työskentelevältä toimintaterapeutilta sekä koulutusohjelmamme koulutuspäälliköltä. Käyttökokeiluiden sekä toimintaterapeuttien palautteiden avulla viimeistelimme suomennetun arviointilomakkeen väittämät. Opinnäytetyön lopuksi pohdimme arviointilomakkeen suomentamisprosessin vaiheita sekä mahdollisia jatkotutkimusehdotuksia. Luovutimme Lasten toimintamahdollisuuksien itsearviointi COSA:n arviointilomakkeen koulutusohjelmamme käyttöön ja mahdollisten jatkotutkimusten kohteeksi.

Cutting edge: stimulation with the cognate self-antigen induces expression of the Ly49A receptor on self-reactive T cells which modulates their responsiveness.

NK cell self-tolerance is maintained by inhibitory receptors specific for MHC class I molecules. Inhibitory NK receptors are also expressed on memory CD8 T cells but their biological relevance on T cells is unclear. In this study, we describe the expression of the Ly49A receptor on a subset of autoreactive T cells which persist in mice double-transgenic for the lymphocytic choriomeningitis virus-derived peptide gp33 and a TCRalphabeta specific for the gp33. No Ly49A-expressing cells are found in TCRalphabeta single-transgenic mice, indicating that the presence of the autoantigen is required for Ly49A induction. Direct evidence for an Ag-specific initiation of Ly49A expression has been obtained in vitro after stimulation of autoreactive TCRalphabeta T cells with the cognate self-Ag. This expression of Ly49A substantially reduces Ag-specific activation of autoreactive T cells. These findings thus suggest that autoantigen-specific induction of inhibitory NK cell receptors on T cells may contribute to peripheral self-tolerance.

c-Myc controls the balance between hematopoietic stem cell self-renewal and differentiation.

The activity of adult stem cells is essential to replenish mature cells constantly lost due to normal tissue turnover. By a poorly understood mechanism, stem cells are maintained through self-renewal while concomitantly producing differentiated progeny. Here, we provide genetic evidence for an unexpected function of the c-Myc protein in the homeostasis of hematopoietic stem cells (HSCs). Conditional elimination of c-Myc activity in the bone marrow (BM) results in severe cytopenia and accumulation of HSCs in situ. Mutant HSCs self-renew and accumulate due to their failure to initiate normal stem cell differentiation. Impaired differentiation of c-Myc-deficient HSCs is linked to their localization in the differentiation preventative BM niche environment, and correlates with up-regulation of N-cadherin and a number of adhesion receptors, suggesting that release of HSCs from the stem cell niche requires c-Myc activity. Accordingly, enforced c-Myc expression in HSCs represses N-cadherin and integrins leading to loss of self-renewal activity at the expense of differentiation. Endogenous c-Myc is differentially expressed and induced upon differentiation of long-term HSCs. Collectively, our data indicate that c-Myc controls the balance between stem cell self-renewal and differentiation, presumably by regulating the interaction between HSCs and their niche.