Methamphetamine binds to α-synuclein and causes a conformational change which can be detected by nanopore analysis

α-Synuclein is an intrinsically disordered protein of 140 amino acids which is abundant in dopaminergic neurons. Misfolding and aggregation of α-synuclein leads to the formation of Lewy bodies inside the neurons which is the hallmark of Parkinson’s disease and related dementias. Here we show by nanopore analysis that the recreational drug, methamphetamine, binds to the N-terminus of α-synuclein and causes a conformational change which cannot be detected by circular dichroism spectroscopy. The results suggest a mechanism for the psychoactivity of methamphetamine as well as an increased incidence of Parkinson’s disease amongst users of the drug.     

Measurement of dietary exposure: a challenging problem which may be overcome thanks to metabolomics?

The diet is an important environmental exposure, and its measurement is an essential component of much health-related research. However, conventional tools for measuring dietary exposure have significant limitations being subject to an unknown degree of misreporting and dependent upon food composition tables to allow estimation of intakes of energy, nutrients and non-nutrient food constituents. In addition, such tools may be inappropriate for use with certain groups of people. As an alternative approach, the recent techniques of metabolite profiling or fingerprinting, which allows simultaneous monitoring of multiple and dynamic components of biological fluids, may provide metabolic signals indicative of food intake. Samples can be analysed through numerous analytical platforms, followed by multivariate data analysis. In humans, metabolomics has been applied successfully in pharmacology, toxicology and medical screening, but nutritional metabolomics is still in its infancy. Biomarkers of a small number of specific foods and nutrients have been developed successfully but less targeted and more high-throughput methods, that do not need prior knowledge of which signals might be discriminatory, and which may allow a more global characterisation of dietary intake, remain to be tested. A proof a principle project (the MEDE Study) is currently underway in our laboratories to test the hypothesis that high-throughput, non-targeted metabolite fingerprinting using flow injection electrospray mass spectrometry can be applied to human biofluids (blood and urine) to characterise dietary exposure in humans.     

Cognitive ability and sentience: which aquatic animals should be protected?

It is of scientific and practical interest to consider the levels of cognitive ability in animals, which animals are sentient, which animals have feelings such as pain and which animals should be protected. A sentient being is one that has some ability to evaluate the actions of others in relation to itself and third parties, to remember some of its own actions and their consequences, to assess risk, to have some feelings and to have some degree of awareness. These abilities can be taken into account when evaluating welfare. There is evidence from some species of fish, cephalopods and decapod crustaceans of substantial perceptual ability, pain and adrenal systems, emotional responses, long- and short-term memory, complex cognition, individual differences, deception, tool use, and social learning. The case for protecting these animals would appear to be substantial. A range of causes of poor welfare in farmed aquatic animals is summarised.     

May preclinical markers of brain infection by HIV be detected? A cognitive, CSF and neuroradiological investigation

A group of patients with HIV infection in various stages of the disease was studied with regard to CSF, neuroradiological and neuropsychological aspects. A considerable number of them showed signs of CNS involvement, as revealed by abnormalities in all the three fields investigated, despite a frequently unremarkable neurological examination. The findings of CSF alterations, neuroradiological abnormalities and selective cognitive impairment in the absence of opportunistic infections of the CNS support the hypothesis of an early and direct action of HIV on the nervous system.     

Analysis of the 5′ flanking sequence of the Gγ globin gene by denaturing gradient gel electrophoresis confirms the heterogeneity of the Bantu βs haplotype

Summary The GCTT polymorphism recently described at positions — 1106 and — 1105 in the 5 flanking region of the G globin gene for the Bantu ^S haplotype was analysed by denaturing gradient gel electrophoresis. We studied 108 ^S chromosome and 122 ^A chromosomes. The TT sequence was found as follows: in all of 80 chromosomes bearing the Bantu ^S haplotype with the 6-bp deletion -400 nt from the G gene in 3 out of 5 Bantu ^S chromosomes without the deletion, in 1 out of 122 ^A chromosomes from different ethnic origins but in none of 23 ^S chromosomes bearing the Senegal, Benin or Cameroon haplotypes. These results confirm the heterogeneity of the Bantu ^S haplotype and allow a tentative evolutionary sequence for the different alleles at this locus to be presented.     

Investigating integument alterations in cubicle housed dairy cows: which types and locations can be combined?

In this study, a data set of 2922 lactating dairy cows in a sample of 64 conventional and organic dairy farms with Holstein Friesian cows in Germany and 31 conventional dairy farms with the dual purpose breed Fleckvieh in Austria was used to screen for correlations between the occurrences of different integument alterations. All cows were housed in cubicle systems. Alterations were classified as hairless areas (H), scabs or wounds (W) or swellings (S) and assessed at 15 locations of the cows’ body. Highest median farm prevalences were found at the joints of the legs, which are already commonly included in studies on integumentary alterations: median farm prevalence was 83% for S and 48% for H at the carpal joints, followed by H (38%) and S (20%) at the lateral tarsal joints and H at the lateral calcanei (20%). Additional body parts with notable median prevalences for H were the hip bones (13%), pin bones (12%) and sacrum (11%). Three cluster models, with 2, 5 and 14 clusters, were built by hierarchical clustering of prevalences of the 30 most relevant alteration location combinations. Clustering revealed that location overruled type of lesion in most cases. Occasionally, clusters represented body segments significantly distant from each other, for example the carpal joints and lateral and dorsal calcanei. However, some neighbouring areas such as the medial and lateral hock area should be analysed separately from each other for causal analysis as they formed distinct clusters.     

Plasma membrane: Can its structure and function be modulated by dietary fat?

• 1.1. Compositional analysis of plasma membranes from rats fed nutritionally adequate diets different in fatty acid composition establishes that fundamentally different dietary fat intake results in alteration in structural lipid composition of plasma membranes in brain, liver and the intestinal mucosa.
• 2.2. Dietary differences in fatty acid intake altered the fatty acyl tail composition of plasma membrane phospholipids in brain, liver and intestinal mucosa.
• 3.3. Diet altered the phospholipid profile observed in brain synaptosomal and liver plasma membrane.
• 4.4. Feeding high vs low polyunsaturated to saturated fat diets for 7 days altered the fatty acid composition of phosphatidylcholine, phosphatidylethanolamine, sphingomyelin and mono-glucosylceramide isolated from plasma membrane of the intestinal mucosa

     

Diabetes and the heart: could the diabetic myocardium be protected by preconditioning?

Both type 1 and type 2 diabetes (insulin-dependent and non-insulin dependent diabetes, respectively) are associated with increased risk for microvascular and macrovascular complications including retinopathy, neuropathy, nephropathy and atherosclerosis. Type 2 diabetes markedly increases the risk for cardiovascular morbidity and mortality, which has major public health implications. In this review, molecular mechanisms pertaining to diabetes-induced heart pathology are addressed.     

Small for gestational age and the metabolic syndrome: which mechanism is suggested by epidemiological and clinical studies?

The metabolic and cardiovascular complications associated with in-utero undernutrition have been identified during the past 10 years. Reduced fetal growth is independently associated with an increased risk of development of cardiovascular diseases, the insulin-resistance syndrome or one of its components (i.e., hypertension, dyslipidaemia, impaired glucose tolerance and type 2 diabetes). Insulin resistance appears to be a key component underlying these metabolic complications. Although the mechanism remains unclear, several pieces of evidence support an active role of adipose tissue in the emergence of insulin resistance (an abnormal growth pattern and repartition, hypersensitivity to catecholamines, regulation of leptin and adiponectin secretion and modulation of peroxisome proliferator-activated receptor gamma). Among individuals born SGA, those who are more at risk of gaining excess adiposity are those who are thin at birth following a period of fetal growth restriction. This period of undernutrition is followed by a neonatal period of catch-up growth and renutrition. This pattern induces important modifications in adipose tissue, with long-term consequences, among which is a high risk of early development of insulin resistance. Not all individuals born SGA will show such modifications in adipose tissue, meaning that not all of those born SGA are at risk of insulin resistance and diabetes. From a broader point of view, several hypotheses have been proposed over the past 10 years to explain this unexpected association between being born SGA and the later development of disease. Each of them points to a detrimental fetal environment, to a genetic susceptibility or to interactions between these two components playing a critical role in this context. Although not confirmed, the hypothesis suggesting that this association could be the consequence of genetic/environmental interactions remains the most attractive.     

Conversion of CO2 into biomass by microalgae: how realistic a contribution may it be to significant CO2 removal?

Microalgae have been proposed as a CO₂ removal option to contribute to climate change avoidance and problems coming from the use of fossil fuels. However, even though microalgae can be used to fix CO₂ from air or flue gases, they do not permit long-term CO₂ storage because they are easily decomposed. On the other hand, microalgae can contribute to an enhancement in human sustainability by producing biofuels as an alternative to fossil fuels in addition to the production of other useful chemicals and commodities. Moreover, microalgae can contribute to enhancing the sustainability of waste treatment processes, reducing the energy consumed, and improving the recycling of nutrients contained within them. This paper reviews the potential contribution of these processes and the existing knowledge in these areas.     

Double-stranded RNA induces sequence-specific antiviral silencing in addition to nonspecific immunity in a marine shrimp: convergence of RNA interference and innate immunity in the invertebrate antiviral response?

Double-stranded RNA (dsRNA) is a common by-product of viral infections and a potent inducer of innate antiviral immune responses in vertebrates. In the marine shrimp Litopenaeus vannamei, innate antiviral immunity is also induced by dsRNA in a sequence-independent manner. In this study, the hypothesis that dsRNA can evoke not only innate antiviral immunity but also a sequence-specific antiviral response in shrimp was tested. It was found that viral sequence-specific dsRNA affords potent antiviral immunity in vivo, implying the involvement of RNA interference (RNAi)-like mechanisms in the antiviral response of the shrimp. Consistent with the activation of RNAi by virus-specific dsRNA, endogenous shrimp genes could be silenced in a systemic fashion by the administration of cognate long dsRNA. While innate antiviral immunity, sequence-dependent antiviral protection, and gene silencing could all be induced by injection of long dsRNA molecules, injection of short interfering RNAs failed to induce similar responses, suggesting a size requirement for extracellular dsRNA to engage antiviral mechanisms and gene silencing. We propose a model of antiviral immunity in shrimp by which viral dsRNA engages not only innate immune pathways but also an RNAi-like mechanism to induce potent antiviral responses in vivo.     

Taste sorting and naming: can taste concepts be misrepresented by traditional psychophysical labelling systems?

Japanese and American subjects were required to sort filterpapers, soaked in taste stimuli, into categories that had conceptuallythe same taste. Both Japanese and Americans sorted in the samemanner, indicating similar conceptualization. Taste names weregiven to the taste categories obtained by using the traditional‘four basic taste’ naming system, common in tastepsychophysics. This method was seen to underestimate the numberof categories actually present. This suggests a re-assessmentof current psychophysical taste-naming techniques.     

Risk attitudes and sun protection behaviour: Can behaviour be altered by using a melanoma genomic risk intervention?

Background: Exposure to ultraviolet radiation from sunlight is directly associated with melanoma skin cancer, however reducing sun-exposure can be difficult to achieve at a population level.Methods: Using a genomic risk information behaviour change trial for melanoma prevention, we classified participants as risk-seeking, risk-neutral or risk-averse for domain-specific risk taking (DOSPERT). One-way ANOVA determined the association between socio-demographic characteristics and risk-taking score, and multivariable linear regression ascertained impact of an individual’s underlying risk propensity on an objective measure of sun-exposure, standard erythemal dose (SED), at 3-months follow-up.Results: Of 119 participants, mean age 53 years; 50% males, 87% had a personal/family history of cancer; 19% were classified risk-seeking, 57% risk-neutral. The mean risk-taking score was significantly higher in younger participants (≤50 years: 13.86 vs. >50 years: 11.11, p = 0.003); and lower in those with a personal/family history of skin cancer versus without (10.55 vs 13.33, p = 0.009). Risk averse individuals had lower weekly mean SEDs at 3-months than risk neutral and risk seeking individuals (2.56, 5.81, 4.81 respectively, p = 0.01). Risk seekers showed fewer sun protective habits (p < 0.001); and higher intentional tanning, (p = 0.01). At 3-months, risk seekers attained 16%–54% lower SEDs in the genomic information group compared with controls, however this was not significantly different across risk groups (interaction p = 0.13).Conclusion: An individual’s underlying risk attitude is likely associated with sun-exposure behaviours, and may modify the effect of a genomic risk information behaviour change intervention. Young people and risk seekers may benefit most from being given information on their genetic risk of melanoma.     

Double-stranded DNA-templated cleavage of oligonucleotides containing a P3���N5�� linkage triggered by triplex formation: the effects of chemical modifications and remarkable enhancement in reactivity

We recently reported double-stranded DNA-templated cleavage of oligonucleotides as a sequence-specific DNA-detecting method. In this method, triplex-forming oligonucleotides (TFOs) modified with 5′-amino-2′,4′-BNA were used as a DNA-detecting probe. This modification introduced a P3′→N5′ linkage (P–N linkage) in the backbone of the TFO, which was quickly cleaved under acidic conditions when it formed a triplex. The prompt fission of the P–N linkage was assumed to be driven by a conformational strain placed on the linkage upon triplex formation. Therefore, chemical modifications around the P–N linkage should change the reactivity by altering the microenvironment. We synthesized 5′-aminomethyl type nucleic acids, and incorporated them into TFOs instead of 5′-amino-2′,4′-BNA to investigate the effect of 5′-elongation. In addition, 2′,4′-BNA/LNA or 2′,5′-linked DNA were introduced at the 3′- and/or 5′-neighboring residues of 5′-amino-2′,4′-BNA to reveal neighboring residual effects. We evaluated the triplex stability and reaction properties of these TFOs, and found out that chemical modifications around the P–N linkage greatly affected their reaction properties. Notably, 2′,5′-linked DNA at the 3′ position flanking 5′-amino-2′,4′-BNA brought significantly higher reactivity, and we succeeded in indicating that a TFO with this modification is promising as a DNA analysis tool.