Activation, regulation and physiology of natural competence in Lactococcus lactis

Lactococcus lactis is a Gram-positive bacterium that is mainly used in dairy products and safe for consumption. Within species, strains might harbour different traits which makes one strain suitable for milk fermentation whereas the other strain is not. However, natural improvement of strain performance important point within the dairy industry. Many bacteria can perform horizontal gene transfer which encompasses natural mechanisms to take up DNA. These mechanisms include phage transduction, nanotubes, conjugation and natural competence. In this study, we examined whether L. lactis can develop natural competence. Strains that appear to have a complete set of competence genes were selected following comparative genomic analysis. A construct, comprising the gene comX encoding the master regulator of competence under control of the nisin promotor, was introduced into the L. lactis strain KF147 which produces ComX upon addition of nisin to the growth medium of L. lactis. Indeed, moderate expression of ComX allowed DNA-uptake from the environment but also efficient integration of homologous fragments into the genome. In addition, the pleiotropic stringent response regulator CodY appears to be involved in the natural competence state and high expression of ComX leads to stagnation of growth, overall stress/ stringent response, however, these cells remain metabolically active. The natural trigger for natural competence could not be established. However, our research shows that there is strong evidence that environmental factors leading to starvation or stringent response in L. lactis might possibly trigger natural competence

Dental Practitioners' Attitudes, Subjective Norms and Intentions to Practice Atraumatic Restorative Treatment (ART) in Tanzania.

The aim of this study was to describe the attitude and subjective norm of dental practitioners towards practicing the atraumatic restorative treatment (ART) in Tanzania. A pre-tested questionnaire on attitudes and subjective norms to practice ART was mailed to all 147 dental practitioners working in the regional and district government clinics. The independent variables were: gender, working experience, qualification and ever heard of ART. The dependent variables were: attitude, subjective norm and intention to practice ART. Chi-square tests and multiple regression analysis were used to test for effects between independent and dependent variables. Significance level was set at 5%. A total of 138 practitioners returned completed questionnaires. More experienced dental practitioners encountered moderate social pressure than less experienced dental practitioners, who met strong social pressure (p=0.045). A total of 73.2% of dental practitioners felt that ART was worth introducing in Tanzania, 92.8% recommended ART training for all dental practitioners and 97.8% recommended inclusion of ART in dental curricula. Positive attitude, strong subjective norm and high intention to practice ART were recorded in 76.3%, 28.1% and 90.6% of the practitioners, respectively. Only subjective norm had a statistically significant influence on the intention to practice ART (p<0.0001). The results indicated that dental practitioners were willing to have ART introduced in Tanzania and had positive attitudes towards practicing this technique. Nevertheless, their intention to perform ART was strongly influenced by social pressures. Therefore, in order to have a successful introduction of ART in Tanzania, people who matter in the daily practice of dental practitioners need to accept and appraise the ART approach positively

Dental practitioners' attitudes, subjective norms and intentions to practice atraumatic restorative treatment (ART) in Tanzania

The aim of this study was to describe the attitude and subjective norm of dental practitioners towards practicing the atraumatic restorative treatment (ART) in Tanzania. A pre-tested questionnaire on attitudes and subjective norms to practice ART was mailed to all 147 dental practitioners working in the regional and district government clinics. The independent variables were: gender, working experience, qualification and ever heard of ART. The dependent variables were: attitude, subjective norm and intention to practice ART. Chi-square tests and multiple regression analysis were used to test for effects between independent and dependent variables. Significance level was set at 5%. A total of 138 practitioners returned completed questionnaires. More experienced dental practitioners encountered moderate social pressure than less experienced dental practitioners, who met strong social pressure (p=0.045). A total of 73.2% of dental practitioners felt that ART was worth introducing in Tanzania, 92.8% recommended ART training for all dental practitioners and 97.8% recommended inclusion of ART in dental curricula. Positive attitude, strong subjective norm and high intention to practice ART were recorded in 76.3%, 28.1% and 90.6% of the practitioners, respectively. Only subjective norm had a statistically significant influence on the intention to practice ART (

VACUTAINER(® )CPT™ and Ficoll density gradient separation perform equivalently in maintaining the quality and function of PBMC from HIV seropositive blood samples

BACKGROUND: For immune monitoring studies during HIV vaccine clinical trials, whole blood specimens from HIV seropositive (HIV(+)) patients may be collected at multiple sites and sent to a central location for peripheral blood mononuclear cell (PBMC) isolation, cryopreservation and functional evaluation. In this study we show a comparison of two PBMC preparation options, Ficoll density gradient separation (Ficoll) and Cell Preparation Tubes (CPT) using shipped whole blood specimens from 19 HIV(+ )patients (CD4 > 350, viral load < 50). The pre- and post- cryopreservation performance of samples collected by these two methods were compared by assessment of antigen-specific IFNγ expression in CD8(+ )and CD8(- )T cells, cellular viability, and cellular recovery. RESULTS: The results indicate that cryopreserved PBMC samples tested for CMV- and HIV- specific interferon-gamma (IFNγ) expression performed equivalent to the respective fresh PBMC processed under both collection conditions. Compared to fresh PBMC, the viability was significantly lower for cryopreserved PBMC derived using Ficoll, although it was never less than 90%. There were no significant differences in the IFNγ response, viability, or recovery between cryopreserved PBMC derived by Ficoll and by CPT. CONCLUSION: These data suggest that CPT is an efficient system for the collection and cryopreservation of functionally active HIV(+ )PBMC, as well as a viable alternative to Ficoll gradient separation

Effects of Individualized Centrifugation Training on Orthostatic Tolerance in Men and Women

Aims Exposure to artificial gravity (AG) at different G loads and durations on human centrifuges has been shown to improve orthostatic tolerance in men. However, the effects on women and of an individual-specific AG training protocol on tolerance are not known. Methods We examined the effects of 90 minutes of AG vs. 90 minutes of supine rest on the orthostatic tolerance limit (OTL), using head up tilt and lower body negative pressure until presyncope of 7 men and 5 women. Subjects were placed in the centrifuge nacelle while instrumented and after one-hour they underwent either: 1) AG exposure (90 minutes) in supine position [protocol 1, artificial gravity exposure], or 2) lay supine on the centrifuge for 90 minutes in supine position without AG exposure [protocol 2, control]. The AG training protocol was individualized, by first determining each subject’s maximum tolerable G load, and then exposing them to 45 minutes of ramp training at sub-presyncopal levels. Results Both sexes had improved OTL (14 minutes vs 11 minutes, p &lt; 0.0019) following AG exposure. When cardiovascular (CV) variables at presyncope in the control test were compared with the CV variables at the same tilt-test time (isotime) during post-centrifuge, higher blood pressure, stroke volume and cardiac output and similar heart rates and peripheral resistance were found post-centrifuge. Conclusions These data suggest a better-maintained central circulating blood volume post-centrifugation across gender and provide an integrated insight into mechanisms of blood pressure regulation and the possible implementation of in-flight AG countermeasure profiles during spaceflights

The influence of music on mood and performance while driving

Mood can influence our everyday behaviour and people often seek to reinforce, or to alter their mood, for example by turning on music. Music listening while driving is a popular activity. However, little is known about the impact of music listening while driving on physiological state and driving performance. In the present experiment, it was investigated whether individually selected music can induce mood and maintain moods during a simulated drive. In addition, effects of positive, negative, and no music on driving behaviour and physiological measures were assessed for normal and high cognitive demanding rides. Subjective mood ratings indicated that music successfully maintained mood while driving. Narrow lane width drives increased task demand as shown in effort ratings and increased swerving. Furthermore, respiration rate was lower during music listening compared to rides without music, while no effects of music were found on heart rate. Overall, the current study demonstrates that music listening in car influences the experienced mood while driving, which in turn can impact driving behaviour. Practitioners Summary: Even though it is a popular activity, little is known about the impact of music while driving on physiological state and performance. We examined whether music can induce moods during high and low simulated drives. The current study demonstrates that in car music listening influences mood which in turn can impact driving behaviour. The current study shows that listening to music can positively impact mood while driving, which can be used to affect state and safe behaviour. Additionally, driving performance in high demand situations is not negatively affected by music

An association study of DRD2 and COMT polymorphisms with novelty seeking and harm avoidance scores, in two independent samples of depressed patients

BACKGROUND: It was recently reported that an interaction of the dopamine D2 receptor (DRD2) and catechol-O-methyltransferase (COMT) influences the behavioural approach system – as measured using Carver and White's Behavioural Inhibition and Behavioural Approach System (BIS/BAS) scales – in a sample of healthy German subjects. The Temperament and Character Inventory (TCI), in particular the novelty seeking (NS) and harm avoidance (HA) scales, correlates moderately with the BIS/BAS measure. This study aimed to examine support for an association of DRD2 and COMT with behavioural activation, using the TCI within two independent samples of depressed outpatients (for both samples n = 146). METHODS: Two clinical samples of depressed patients were ascertained to assess the efficacy of two different pharmacotherapy and psychotherapy treatments. Analysis of variance (ANOVA) was used to analyse NS and HA scale and subscale scores with respect to gene loci within each clinical sample. Analysis of covariance were undertaken to examine the association of age and gender with NS and HA scores. An association of age group or gender with gene loci were explored using chi-squared tests, in each sample. RESULTS: No significant effect of DRD2 or COMT, either independently or as an interaction, on NS or HA scores was observed, within either sample. Whilst age was significantly negatively associated with NS scores, including age in the two- and three-way interactions did not affect the significance of the association of personality with gene loci. CONCLUSION: This study suggests that the COMT-DRD2 Equilibrium Model of Positive Emotionality recently proposed by Reuter and his colleagues is not applicable amongst currently depressed individuals, whose behavioural approach and inhibition tendencies have been assessed using the TCI

Dissecting the determinants of depressive disorders outcome: an in depth analysis of two clinical cases

Clinicians face everyday the complexity of depression. Available pharmacotherapies and psychotherapies improve patients suffering in a large part of subjects, however up to half of patients do not respond to treatment. Clinicians may forecast to a good extent if a given patient will respond or not, based on a number of data and sensations that emerge from face to face assessment. Conversely, clinical predictors of non response emerging from literature are largely unsatisfactory. Here we try to fill this gap, suggesting a comprehensive assessment of patients that may overcome the limitation of standardized assessments and detecting the factors that plausibly contribute to so marked differences in depressive disorders outcome. For this aim we present and discuss two clinical cases. Mr. A was an industrial manager who came to psychiatric evaluation with a severe depressive episode. His employment was demanding and the depressive episode undermined his capacity to manage it. Based on standardized assessment, Mr. A condition appeared severe and potentially dramatic. Mrs. B was a housewife who came to psychiatric evaluation with a moderate depressive episode. Literature predictors would suggest Mrs. B state as associated with a more favourable outcome. However the clinician impression was not converging with the standardized assessment and in fact the outcome will reverse the prediction based on the initial formal standard evaluation. Although the present report is based on two clinical cases and no generalizability is possible, a more detailed analysis of personality, temperament, defense mechanisms, self esteem, intelligence and social adjustment may allow to formalize the clinical impressions used by clinicians for biologic and pharmacologic studies