Chemosensory learning in the chicken embryo

Examined how exposure to a chemosensory stimulus prior to hatching affects subsequent chemosensory preferences of newly hatched chicks. The chicks' preferences were assessed at 2 days after hatching using an olfactory preference test (strawberry-smelling shavings vs water-coated shavings) and at 4 days after hatching using a gustatory preference test (strawberry-flavoured water vs unflavoured water). With no exposure to strawberry before hatching, strawberry was highly aversive to chicks after hatching. However, following exposure to strawberry before hatching, chicks expressed a greater preference for (or weaker aversion to) the strawberry stimulus. Chicks exposed to strawberry before hatching drank more strawberry-flavoured water and spent more time in a strawberry-scented area than chicks having no exposure before hatching. This change in preference was specific to the stimulus experienced before hatching and was present in the absence of any posthatching exposure to the stimulus. Results demonstrate that a chick's chemosensory preferences are changed as a result of experience with a stimulus before hatching and are suggestive of learning.

Persistent measles virus infection of mouse neural cells lacking known human entry receptors

Aims: Infection of the mouse central nervous system with wild type (WT) and vaccine strains of measles virus (MV) results in lack of clinical signs and limited antigen detection. It is considered that cell entry receptors for these viruses are not present on murine neural cells and infection is restricted at cell entry.

Methods: To examine this hypothesis, virus antigen and caspase 3 expression (for apoptosis) was compared in primary mixed, neural cell cultures infected in vitro or prepared from mice infected intracerebrally with WT, vaccine or rodent neuroadapted viruses. Viral RNA levels were examined in mouse brain by nested and real-time reverse transcriptase polymerase chain reaction.

Results: WT and vaccine strains were demonstrated for the first time to infect murine oligodendrocytes in addition to neurones despite a lack of the known MV cell receptors. Unexpectedly, the percentage of cells positive for viral antigen was higher for WT MV than neuroadapted virus in both in vitro and ex vivo cultures. In the latter the percentage of positive cells increased with time after mouse infection. Viral RNA (total and mRNA) was detected in brain for up to 20 days, while cultures were negative for caspase 3 in WT and vaccine virus infections.

Conclusions: WT and vaccine MV strains can use an endogenous cell entry receptor(s) or alternative virus uptake mechanism in murine neural cells. However, viral replication occurs at a low level and is associated with limited apoptosis. WT MV mouse infection may provide a model for the initial stages of persistent MV human central nervous system infections.

Wholeness of healing: an innovative Student-Selected Component introducing United Kingdom medical students to the spiritual dimension in healthcare.

Objective: This Student Selected Component (SSC) was designed to equip United Kingdom (UK) medical students to engage in whole-person care. The aim was to explore students' reactions to experiences provided, and consider potential benefits for future clinical practice.

Methods: The SSC was delivered in the workplace. Active learning was encouraged through facilitated discussion with and observation of clinicians, the palliative team, counselling services, hospital chaplaincy and healing ministries; sharing of medical histories by patients; and training in therapeutic communication. Assessment involved reflective journals, literature appraisal, and role-play simulation of the doctor-patient consultation. Module impact was evaluated by analysis of student coursework and a questionnaire.

Results: Students agreed that the content was stimulating, relevant, and enjoyable and that learning outcomes were achieved. They reported greater awareness of the benefit of clinicians engaging in care of the "whole person" rather than "the disease." Contributions of other professions to the healing process were acknowledged, and students felt better equipped for discussion of spiritual issues with patients. Many identified examples of activities which could be incorporated into core teaching to benefit all medical students.

Conclusion: The SSC provided relevant active learning opportunities for medical students to receive training in a whole-person approach to patient care.

Responses of calves to acute stress: Individual consistency and relations between behavioral and physiological measures

The present study examined the consistency over time of individual differences in behavioral and physiological responsiveness of calves to intuitively alarming test situations as well as the relationships between behavioral and physiological measures. Twenty Holstein Friesian heifer calves were individually subjected to the same series of two behavioral and two hypothalamo-pituitary-adrenocortical (HPA) axis reactivity tests at 3, 13 and 26 weeks of age. Novel environment (open field, OF) and novel object (NO) tests involved measurement of behavioral, plasma cortisol and heart rate responses. Plasma ACTH and/or cortisol response profiles were determined after administration of exogenous CRH and ACTH, respectively, in the HPA axis reactivity tests. Principal component analysis (PCA) was used to condense correlated measures within ages into principal components reflecting independent dimensions underlying the calves' reactivity. Cortisol responses to the OF and NO tests were positively associated with the latency to contact and negatively related to the time spent in contact with the NO. Individual differences in scores of a principal component summarizing this pattern of inter-correlations, as well as differences in separate measures of adrenocortical and behavioral reactivity in the OF and NO tests proved highly consistent over time. The cardiac response to confinement in a start box prior to the OF test was positively associated with the cortisol responses to the OF and NO tests at 26 weeks of age. HPA axis reactivity to ACTH or CRH was unrelated to adrenocortical and behavioral responses to novelty. These findings strongly suggest that the responsiveness of calves was mediated by stable individual characteristics. Correlated adrenocortical and behavioral responses to novelty may reflect underlying fearfulness, defining the individual's susceptibility to the elicitation of fear. Other independent characteristics mediating reactivity may include activity or coping style (related to locomotion) and underlying sociality (associated with vocalization). (c) 2005 Elsevier Inc. All rights reserved.

Sedentary aging increases resting and exercise-induced intramuscular free radical formation

Mitochondrial free radical formation has been implicated as a potential mechanism underlying degenerative senescence, although human data are lacking. Therefore, the present study was designed to examine if resting and exercise-induced intramuscular free radical-mediated lipid peroxidation is indeed increased across the spectrum of sedentary aging. Biopsies were obtained from the vastus lateralis in six young (26 ± 6 yr) and six aged (71 ± 6 yr) sedentary males at rest and after maximal knee extensor exercise. Aged tissue exhibited greater (P < 0.05 vs. the young group) electron paramagnetic resonance signal intensity of the mitochondrial ubisemiquinone radical both at rest (+138 ± 62%) and during exercise (+143 ± 40%), and this was further complemented by a greater increase in a-phenyl-tert-butylnitrone adducts identified as a combination of lipid-derived alkoxyl-alkyl radicals (+295 ± 96% and +298 ± 120%). Lipid hydroperoxides were also elevated at rest (0.190 ± 0.169 vs. 0.148 ± 0.071 nmol/mg total protein) and during exercise (0.567 ± 0.259 vs. 0.320 ± 0.263 nmol/mg total protein) despite a more marked depletion of ascorbate and uptake of a/ß-carotene, retinol, and lycopene (P < 0.05 vs. the young group). The impact of senescence was especially apparent when oxidative stress biomarkers were expressed relative to the age-related decline in mitochondrial volume density and absolute power output at maximal exercise. In conclusion, these findings confirm that intramuscular free radical-mediated lipid peroxidation is elevated at rest and during acute exercise in aged humans.

Contribution of 30 Biomarkers to 10-year cardiovascular risk estimation in 2 population cohorts: The MONICA, risk, genetics, archiving and monograph (MORGAM) biomarker project

Background— Cardiovascular risk estimation by novel biomarkers needs assessment in disease-free population cohorts, followed up for incident cardiovascular events, assaying the serum and plasma archived at baseline. We report results from 2 cohorts in such a continuing study.
Methods and Results— Thirty novel biomarkers from different pathophysiological pathways were evaluated in 7915 men and women of the FINRISK97 population cohort with 538 incident cardiovascular events at 10 years (fatal or nonfatal coronary or stroke events), from which a biomarker score was developed and then validated in the 2551 men of the Belfast Prospective Epidemiological Study of Myocardial Infarction (PRIME) cohort (260 events). No single biomarker consistently improved risk estimation in FINRISK97 men and FINRISK97 women and the Belfast PRIME Men cohort after allowing for confounding factors; however, the strongest associations (with hazard ratio per SD in FINRISK97 men) were found for N-terminal pro-brain natriuretic peptide (1.23), C-reactive protein (1.23), B-type natriuretic peptide (1.19), and sensitive troponin I (1.18). A biomarker score was developed from the FINRISK97 cohort with the use of regression coefficients and lasso methods, with selection of troponin I, C-reactive protein, and N-terminal pro-brain natriuretic peptide. Adding this score to a conventional risk factor model in the Belfast PRIME Men cohort validated it by improved c-statistics (P=0.004) and integrated discrimination (P<0.0001) and led to significant reclassification of individuals into risk categories (P=0.0008).
Conclusions— The addition of a biomarker score including N-terminal pro-brain natriuretic peptide, C-reactive protein, and sensitive troponin I to a conventional risk model improved 10-year risk estimation for cardiovascular events in 2 middle-aged European populations. Further validation is needed in other populations and age groups.

Heart Rhythm UK position statement on clinical indications for implantable cardioverter defibrillators in adult patients with familial sudden cardiac death syndromes

Whilst the decision regarding defibrillator implantation in a patient with a familial sudden cardiac death syndrome is likely to be most significant for any particular individual, the clinical decision-making process itself is complex and requires interpretation and extrapolation of information from a number of different sources. This document provides recommendations for adult patients with the congenital Long QT syndromes, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy. Although these specific conditions differ in terms of clinical features and prognosis, it is possible and logical to take an approach to determining a threshold for implantable cardioveter-defibrillator implantation that is common to all of the familial sudden cardiac death syndromes based on estimates of absolute risk of sudden death. Published on behalf of the European Society of Cardiology. © The Author 2010.