Selective inhibition of early--but not late--expressed HIF-1α is neuroprotective in rats after focal ischemic brain damage

The expression of hypoxia-inducible factor-1-alpha (HIF-1α) is upregulated in ischemic stroke, but its function is still unclear. In the present study, biphasic expression of HIF-1α was observed during 1-12 h and after 48 h in neurons exposed to ischemic stress in vitro and in vivo. Treating neurons with 2-methoxyestradiol (2ME2) 0.5 h after ischemic stress or pre-silencing HIF-1α with small interfering RNA (siRNA) decreased brain injury, brain edema and number of apoptotic cell, and downregulates Nip-like protein X (Nix) expression. Conversely, applying 2ME2 to neurons 8 h after ischemic stress or silencing the HIF-1α with siRNA 12 h after oxygen-glucose deprivation (OGD) increased neuron damage and decreased vascular endothelial growth factor (VEGF) expression. Taken together, these results demonstrate that HIF-1α induced by ischemia in early and late times leads cellular apoptosis and survival, respectively, and provides a new insight into the divergent roles of HIF-1α expression in neurons after ischemic stroke.     

Aging of the brain, neurotrophin signaling, and Alzheimer's disease: is IGF1-R the common culprit?

The last decade has revealed that the lifespan of an organism can be modulated by the signaling pathway that acts downstream of the insulin/insulin-like growth factor 1 receptors (IR/IGF1-R), indicating that there is a “program” that drives the process of aging. New results have now linked the same pathway to the neurogenic capacities of the aging brain, to neurotrophin signaling, and to the molecular pathogenesis of Alzheimer's disease. Therefore, a common signaling cascade now seems to link aging to age-associated pathologies of the brain, suggesting that pharmacologic approaches aimed at the modulation of this pathway can serve to delay the onset of age-associated disorders and improve the quality of life. Work from a wide range of fields performed with different approaches has already identified some of the signaling molecules that act downstream of IGF1-R, and has revealed that a delicate checkpoint exists to balance excessive growth/“immortality” and reduced growth/“senescence” of a cell. Future research will determine how far the connection goes and how much of it we can influence.     

For the Overweight,is Proximity to In-Shape,Normal-Weight Exercisers a Deterrent or an Attractor? An Examination of Contextual Preferences

Background

For the overweight, is the thought of exercising in close proximity to physically fit, normal-weight individuals a deterrent or an attractor? Efforts to address this question stand to inform future intervention-based research.

Purpose

The purpose of the study was to examine whether overweight individuals possess a preference for exercising alongside similarly overweight (relative to in-shape, normalweight) persons.

Methods

Relying upon an experimental paradigm, American participants evaluated one of four exercise contexts and completed a measure of social physique anxiety.

Results

Overweight participants high in social physique anxiety exhibited a preference for exercise contexts comprised of other overweight individuals whereas overweight participants low in physique anxiety exhibited a preference for contexts comprised of in-shape, normal-weight individuals. A relative preference for social contexts among normal-weight participants was not observed.

Conclusions

These findings suggest that the provision of group-based programs designed exclusively for the overweight may be appropriate for overweight individuals anxious about the evaluation of their physique. These results also suggest that such programs may conflict with the preferences of overweight persons with a low degree of social physique anxiety. Thus, for the overweight (but not the normal-weight), exercising in close proximity to in-shape, normal-weight individuals can be both a deterrent and an attractor.     

Is chronic fatigue syndrome caused by a rare brain infection of a common,normally benign virus?

Chronic fatigue syndrome (CFS) is a disabling disease of unknown aetiology. A variety of factors have been suggested as possible causes. Although the symptoms and clinical findings are heterogeneous, the syndrome is sufficiently distinct, at least in relation to the more obvious cases, that a common explanation seems likely. In this paper, it is proposed that the disease is caused by a ubiquitous, but normally benign virus, e.g., one of the circoviruses. Circoviruses are chronically present in a majority of people, but are rarely tested for diagnostically. Normally these viruses do not penetrate the blood-brain barrier, but exceptions have been reported, and related viruses cause disease in the central nervous system of animals. The flu-like illness that often precedes the onset of CFS may either suppress immune function, causing an increased viremia, and/or lower the blood-brain barrier. In both cases the result may be that a virus already present in the blood enters the brain. It is well known that zoonotic viruses typically are more malignant than viruses with a long history of host-virus evolution. Similarly, a virus reaching an unfamiliar organ may cause particular problems.     

Dyadic,triadic, and group models of peer supervision/consultation: What are their components,and is there evidence of their effectiveness?

Models that meet the Psychology Board of Australia's definition of peer consultation include dyadic, triadic, and group formats. Components of these models (e.g., goals, theoretical basis, role of leader, members' roles, structure, and steps in procedure, stages in group development) are presented, and evidence of their effectiveness is reviewed. Psychologists are encouraged to identify the model components and goals that match their own learning goals for continuing professional development.     

The neurotoxicity of β-amyloid peptide toward rat brain is associated with enhanced oxidative stress,inflammation and apoptosis,all of which can be attenuated by scutellarin

This study was designed to investigate the processes underlying the neurotoxicity induced by β-amyloid peptide (Aβ) in the rat brain, as well as to examine whether scutellarin (Scu) can prevent this neurotoxicity. Thirty Wistar rats were randomly divided into 3 groups, i.e., untreated (control), treated with Aβ and treated with both Aβ and Scu. The treated rats were subjected to bilateral intracerebroventricular injection of Aβ_25–35 with or without subsequent dietary exposure to Scu. Learning and memory were assessed with the Morris water maze test; the activities of superoxide dismutase (SOD) and monoamine oxidase (MAO) were assayed biochemically; expression of the interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) proteins was determined by immunohistochemistry; and neuronal apoptosis was detected with Annexin staining followed by flow cytometry. The animals treated with Aβ exhibited impaired learning and memory; reduced SOD and elevated MAO activity, elevated protein levels of IL-1β, IL-6 and TNF-α; and a higher percentage of apoptotic neurons in the brain. Interestingly, all of these effects were ameliorated by administration of Scu. These findings indicate that the deficits in learning and memory demonstrated by the rats receiving Aβ are due to elevated oxidative stress and inflammation, which result in apoptosis and that Scu may prevent these deleterious effects.     

Pineal attrition, loss of cognitive plasticity, and onset of puberty during the teen years: is it a modern maladaptation exposed by evolutionary displacement?

Cognitive plasticity, a developmental trait that promotes acquisition of complex skills such as language or playing musical instruments, diminishes substantially during puberty. The loss of plasticity has been attributed to surge of sex steroids during adolescence, but the phenomenon remains poorly understood. We hypothesize that pineal involution during puberty may contribute to plasticity decay. The pineal gland produces melatonin, the level of which declines dramatically during onset of puberty. Emerging evidence suggest that melatonin may modulate cognitive plasticity, independent of the effects of sex steroids, and low sex steroids and high melatonin may be simultaneously required to maintain cognitive plasticity. Potential mechanisms by which melatonin may modulate plasticity are examined within the sleep and hippocampal long-term potentiation frameworks. Implications for psychiatric conditions that involve sleep disorders and learning dysfunctions such as schizophrenia and autism are discussed, and the potential adaptive roles of postprandial and postcoital sleep are explored. From the Darwinian perspective, development and reproductive maturity may represent distinct phases that require tailored cognitive strategies to maximize fitness. While cognitive flexibility and susceptibility to new skills may be paramount during development, reduced cognitive flexibility and increased cognitive determinism may enable more efficient responses to stimuli during adulthood. Thus, cognitive plasticity and cognitive determinism may represent trade-off adaptations and different dimensions of intelligence. The decline of plasticity and emergence of puberty during the second decade may be relics of prehistoric times when the human lifespan was short and the environment was relatively simple and static. Today, when the environment is more complex and dynamic, and humans are living far longer, the early obsolescence of plasticity during puberty may represent a Darwinian inefficiency exposed by evolutionary displacement. Regulation of plasticity may be a systemic phenomenon, as exemplified by the association of learning disability with allergic conditions, a form of immune plasticity dysfunction. Ramifications for other plastic functions that decline during puberty such as wound healing and hyaline cartilage regeneration are explored. Like the plasticity of immunity and cognition, the plasticity of hyaline cartilage during youth may enable hosts to respond to ecologic opportunities and generate the optimally adapted adult phenotype. Pineal involution may represent a potential target for therapeutic extension or restoration of plasticity after puberty. Extending plasticity may have far-reaching consequences for human evolution.     

Food additives,food and the concept of ‘food addiction’: Is stimulation of the brain reward circuit by food sufficient to trigger addiction?

In the last few years, the concept of ‘food addiction’ has continued to gain popularity, with human and animal studies demonstrating the differential effects of foods that are high in fat, sugar or protein on appetite, satiety, eating behaviour and the development of food addiction. However, a number of studies have disputed the occurrence of food addiction in humans. Questions have also arisen regarding the possible impacts that food additives may have on the development of food addiction or eating disorders. Also, it is known that alterations in food composition and the presence of food additives (flavour enhancers, sugars, sugar substitutes, and non-nutritive sweeteners) are factors that generally influence the sensory perception of food. Our understanding of the potential roles of central neurotransmitters (such as dopamine) and certain neuropeptides in the evolution of food addiction is also evolving; but presently, there isn’t sufficient scientific evidence to consider any food ingredient, micronutrient or standard food-additive as addictive. In this review, the relevant literatures dealing with the concept of ‘food addiction’ are examined, and the factors which may predispose to food addiction are discussed. The possible influences that flavour-enhancers, sugars, sugar substitutes and non-nutritive sweeteners may exert on central neurotransmission, neurotransmitter/receptor interactions, appetite, satiety, conditioned- preferences and the brain reward system are also highlighted.     

What is the most relevant standard of success in assisted reproduction? Redefining success in the context of elective single embryo transfer: evidence, intuition and financial reality

Treatment-related multiple pregnancy poses the biggest threat to the safety of IVF. Despite a double embryo transfer (DET) policy in most European centres, twin rates continue to be unacceptably high, at 20-35%. Elective single embryo transfer (SET) is an effective way to minimize twin pregnancies, but the debate surrounding its routine clinical use continues. A review of the literature was undertaken in order to seek evidence about the effectiveness of SET, and identify barriers to its acceptance in clinical practice. Data from randomized controlled trials (RCTs) indicate that SET results in lower live birth rates per fresh IVF cycle (odds ratio 0.53; 95% confidence interval 0.31-0.89; P = 0.02) in comparison with DET. Data on cumulative live birth rates are unavailable from RCTs, although the expectation is that these are comparable in the two groups. SET is unlikely to be suitable for all women undergoing IVF and outcomes may be sensitive to different laboratory protocols. The perceived effectiveness of SET is influenced by the way existing evidence is interpreted. Other factors affecting the routine use of SET include laboratory techniques, individual preferences and funding issues.     

Determination of serum antibodies against swine-origin influenza A virus H1N1/09 by immunofluorescence, haemagglutination inhibition, and by neutralization tests: how is the prevalence rate of protecting antibodies in humans?

In April 2009, a new variant of influenza A virus, subtype H1N1v emerged in Mexico and spread all over the world producing the H1N1 pandemic in mankind after 1918–1920 and 1978/1979. Obviously there was no herd immunity against this new virus variant. Mainly young people, but less elderly were affected and presented severe and even lethal courses of disease. Since virus-specific antibodies are commonly regarded as markers of partial or complete immunoprotection, we performed antibody determinations in serum samples obtained from people before and after the pandemic has arrived in our region (Frankfurt/M., Germany). The assays were done by indirect immunofluorescence, by neutralization test, and by a haemagglutination inhibition test (HI), which was established in a practical modification for general and easy use. Among 145 individuals, of whom serum specimens had been drawn before the onset of pandemic, 19 revealed humoral immunity, i.e. titres of H1N1v neutralizing antibodies (at least 1:64). Eleven were older than 60 years, one belonged to the age group 40–59 years, three to the age group 20–39 years, and two to the age group 15–19 years. After the onset of pandemic in Frankfurt, serum specimens drawn from n = 225 randomly selected patients of our local university hospital were investigated for antibodies against H1N1v by HI, which is generally recommended for routine check of immunity. Twenty-eight individuals revealed the protecting antibody titre of at least 1:40. The age distribution had moved to mean age groups. The results fit to the incidence of influenza A/H1N1(09) disease, as confirmed by RT–PCR in patients admitted to our hospital, peaking in the younger age groups up to 30 years (second affected group: 30–40 years). While commonly used solid-phase antibody tests (like immunofluorescence) are not suitable to diagnose passed H1N1(09) infection and acquired immunity, this can be easily done by HI. Expecting the next waves of influenza A/H1N1v infections, HI testing may avoid vaccinations under special risk of severe or hidden adverse reactions.     

What evidence is there to support skill mix changes between GPs,pharmacists and practice nurses in the care of elderly people living in the community?

Background

Workforce shortages in Australia are occurring across a range of health disciplines but are most acute in general practice. Skill mix change such as task substitution is one solution to workforce shortages. The aim of this systematic review was to explore the evidence for the effectiveness of task substitution between GPs and pharmacists and GPs and nurses for the care of older people with chronic disease. Published, peer reviewed (black) and non-peer reviewed (grey) literature were included in the review if they met the inclusion criteria.

Results

Forty-six articles were included in the review. Task substitution between pharmacists and GPs and nurses and GPs resulted in an improved process of care and patient outcomes, such as improved disease control. The interventions were either health promotion or disease management according to guidelines or use of protocols, or a mixture of both. The results of this review indicate that pharmacists and nurses can effectively provide disease management and/or health promotion for older people with chronic disease in primary care. While there were improvements in patient outcomes no reduction in health service use was evident.

Conclusion

When implementing skill mix changes such as task substitution it is important that the health professionals' roles are complementary otherwise they may simply duplicate the task performed by other health professionals. This has implications for the way in which multidisciplinary teams are organised in initiatives such as the GP Super Clinics.

     

A systematic review of existing peripheral biomarkers of cognitive aging: Is there enough evidence for biomarker proxies in behavioral modification interventions?: An initiative in association with the nutrition,exercise and lifestyle team of the Canadian Consortium on Neurodegeneration in Aging

Peripheral biomarkers have shown significant value in predicting brain health and may serve as a useful proxy measurement in the assessment of evidence-based lifestyle behavior modification programs, including physical activity and nutrition programs, that aim to maintain cognitive function in late life. The aim of this systematic review was to elucidate which peripheral biomarkers are robustly associated with cognitive function among relatively healthy non-demented older adults. Following the standards for systematic reviews (PICO, PRIMSA), and employing MEDLINE and Scopus search engines, 222 articles were included in the review. Based on the review of biomarker proxies of cognitive health, it is recommended that a comprehensive biomarker panel, or biomarker signature, be developed as a clinical end point for behavior modification trials aimed at enhancing cognitive function in late life. The biomarker signature should take a multisystemic approach, including lipid, immune/inflammatory, and metabolic biomarkers in the biological signature index of cognitive health.