Cellular localisation of polyphenol oxidase and peroxidase activity in Litchi chinensis Sonn. pericarp

Cellular localisation of visual browning and oxidative activity studies were conducted to determine the relative significance of polyphenol oxidase (PPO) and peroxidase (POD) activities during pericarp browning. Pericarp browning was first observed on the protuberance apices and subsequently extended uniformly over the entire pericarp surface. Anatomically, browning was highly localised and restricted to the epicarp and the upper mesocarp. PPO and POD activities were highest in the epicarp, with progressively less activity in both the mesocarp and endocarp. In situ localisation of oxidative activity using tissue blots confirmed high epicarp PPO activity. POD activity, although primarily restricted to mesocarp vascular tissue, was also detected in the epicarp. We believe that litchi pericarp browning is due to highly localised oxidative activity in the epicarp and upper mesocarp. As PPO and POD activities were significantly higher in this tissue and browning was not observed when both enzymes were selectively inhibited, it is postulated that both PPO and POD activities are associated with litchi pericarp browning. The current theory that litchi pericarp browning is only caused by PPO activity needs to be re-appraised to determine the relative role of POD activity

Acute tryptophan depletion attenuates conscious appraisal of social emotional signals in healthy female volunteers

Rationale: Acute tryptophan depletion (ATD) decreases levels of central serotonin. ATD thus enables the cognitive effects of serotonin to be studied, with implications for the understanding of psychiatric conditions, including depression. Objective: To determine the role of serotonin in conscious (explicit) and unconscious/incidental processing of emotional information. Materials and methods: A randomized, double-blind, cross-over design was used with 15 healthy female participants. Subjective mood was recorded at baseline and after 4 h, when participants performed an explicit emotional face processing task, and a task eliciting unconscious processing of emotionally aversive and neutral images presented subliminally using backward masking. Results: ATD was associated with a robust reduction in plasma tryptophan at 4 h but had no effect on mood or autonomic physiology. ATD was associated with significantly lower attractiveness ratings for happy faces and attenuation of intensity/arousal ratings of angry faces. ATD also reduced overall reaction times on the unconscious perception task, but there was no interaction with emotional content of masked stimuli. ATD did not affect breakthrough perception (accuracy in identification) of masked images. Conclusions: ATD attenuates the attractiveness of positive faces and the negative intensity of threatening faces, suggesting that serotonin contributes specifically to the appraisal of the social salience of both positive and negative salient social emotional cues. We found no evidence that serotonin affects unconscious processing of negative emotional stimuli. These novel findings implicate serotonin in conscious aspects of active social and behavioural engagement and extend knowledge regarding the effects of ATD on emotional perception

Attitudes of the general public towards the disclosure of individual research results and incidental findings from biobank genomic research in Australia

Background Over the past decade, managing the disclosure of findings of genomic research has been the subject of extensive scientific, ethical and legal commentary and is a major challenge for biobanks. Aims To examine views of the general Australian public about the disclosure of individual research results (IRR) and incidental findings (IF) from biobank genomic research. Methods A national computer assisted telephone interview was conducted amongst a representative sample of (n = 800) adult residents across each Australian State and Territory. Results The majority of the Australian general public would be interested in receiving IRR and IF if they allowed their blood/tissue to be used in research; 94.4% (n = 800) reported that they would like to receive ‘specific information obtained from your sample that may be important to your health or treatment’, and 83.4% their ‘potential genetic risk of an inherited disease’. Although fewer desired to receive ‘any IF that were not directly related to your (potential) diagnosed condition’ (70.0%), most would still like to receive IF. A latent class analysis on the desire to receive (or not) all types of results revealed differences in preferences in the information they wished to receive. Conclusion The majority of Australians desire to receive most information arising from research involving their tissue, including IRR and IF. Differences in the extent and type of information they desire to receive are noted. Biobanks must establish strategies to identify information needs of donors, assess research data and communicate with donors and donor families. Processes need to take account of differences in donor preferences and in the clinical or research context(s).National Health and Medical Research Council-funded study (APP10292

Laminin and fibronectin in rectal adenocarcinoma: relationship to tumour grade, stage and metastasis.

Using an immunoperoxidase procedure, we have examined the distribution of laminin and fibronectin in normal human large intestinal mucosa and in 50 cases of rectal adenocarcinoma for which extensive clinical follow up was available. In normal tissue, laminin staining was largely restricted to basement membranes, including that underlying the epithelial cells, whereas fibronectin was found in both basement membranes and surrounding connective tissue. In rectal carcinomas, basement membrane-like staining for laminin associated with tumour cells was found in only 27 out of the 50 cases studied. Statistical analysis showed that the presence of laminin-containing basement membranes was correlated with low histological grade (well-differentiated tumours), but not with stage (progression through the bowel wall and the development of lymph node metastases) and, in a highly significant way, with a reduced incidence of distant metastases and increased patient survival. Although fibronectin was found in tumour cell basement membranes where these were present, it was also found in the stroma of all 50 tumours. There was no apparent correlation between the presence of stromal fibronectin and grade, stage or development of metastases. Finally, attention is drawn to some of the technical difficulties in detecting basement membrane antigens in formalin-fixed tissue, the material most frequently available for retrospective study

Potential benefits of healthy food and lifestyle policies for reducing coronary heart disease mortality in Turkish adults by 2025: a modelling study

Objective This study uses a modelling approach to compare the potential impact of future risk factor scenarios relating to smoking, physical activity levels, dietary salt, saturated fat intake, mean body mass index (BMI) levels, diabetes prevalence and fruit and vegetable (F&V) consumption on future coronary heart disease (CHD) mortality in Turkey for year 2025. Design A CHD mortality model previously developed and validated in Turkey was extended to predict potential trends in CHD mortality from 2008 to 2025. Setting Using risk factor trends data from recent surveys as a baseline, we modelled alternative evidence-based future risk factor scenarios (modest/ideal scenarios). Probabilistic sensitivity analyses were conducted to account for uncertainties. Subject Projected populations in 2025 (aged 25–84) of 54 million in Turkey. Results Assuming lower mortality, modest policy changes in risk factors would result in ∼25 635 (range: 20 290–31 125) fewer CHD deaths in the year 2025; 35.6% attributed to reductions in salt consumption, 20.9% to falls in diabetes, 14.6% to declines in saturated fat intake and 13.6% to increase in F&V intake. In the ideal scenario, 45 950 (range: 36 780–55 450) CHD deaths could be prevented in 2025. Again, 33.2% of this would be attributed to reductions in salt reduction, 19.8% to increases in F&V intake, 16.7% to reductions in saturated fat intake and 14.0% to the fall in diabetes prevalence. Conclusions Only modest risk factor changes in salt, saturated/unsaturated fats and F&V intake could prevent around 16 000 CHD deaths in the year 2025 in Turkey, even assuming mortality continues to decline. Implementation of population-based, multisectoral interventions to reduce salt and saturated fat consumption and increase F&V consumption should be scaled up in Turkey

Modulation of emotional appraisal by false physiological feedback during fMRI

BACKGROUND James and Lange proposed that emotions are the perception of physiological reactions. Two-level theories of emotion extend this model to suggest that cognitive interpretations of physiological changes shape self-reported emotions. Correspondingly false physiological feedback of evoked or tonic bodily responses can alter emotional attributions. Moreover, anxiety states are proposed to arise from detection of mismatch between actual and anticipated states of physiological arousal. However, the neural underpinnings of these phenomena previously have not been examined. METHODOLOGY/PRINCIPAL FINDINGS We undertook a functional brain imaging (fMRI) experiment to investigate how both primary and second-order levels of physiological (viscerosensory) representation impact on the processing of external emotional cues. 12 participants were scanned while judging face stimuli during both exercise and non-exercise conditions in the context of true and false auditory feedback of tonic heart rate. We observed that the perceived emotional intensity/salience of neutral faces was enhanced by false feedback of increased heart rate. Regional changes in neural activity corresponding to this behavioural interaction were observed within included right anterior insula, bilateral mid insula, and amygdala. In addition, right anterior insula activity was enhanced during by asynchronous relative to synchronous cardiac feedback even with no change in perceived or actual heart rate suggesting this region serves as a comparator to detect physiological mismatches. Finally, BOLD activity within right anterior insula and amygdala predicted the corresponding changes in perceived intensity ratings at both a group and an individual level. CONCLUSIONS/SIGNIFICANCE Our findings identify the neural substrates supporting behavioural effects of false physiological feedback, and highlight mechanisms that underlie subjective anxiety states, including the importance of the right anterior insula in guiding second-order "cognitive" representations of bodily arousal state