Staying awake--a genetic region that hinders α2 adrenergic receptor agonist-induced sleep

How external stimuli prevent the onset of sleep has been little studied. This is usually considered to be a non-specific type of phenomenon. However, the hypnotic drug dexmedetomidine, an agonist at α₂ adrenergic receptors, has unusual properties that make it useful for investigating this question. Dexmedetomidine is considered to produce an ‘arousable’ sleep-like state, so that patients or animals given dexmedetomidine become alert following modest stimulation. We hypothesized that it might be more difficult to make mice unconscious with dexmedetomidine if there was a sufficient external stimulus. Employing a motorized rotating cylinder, which provided a continuous and controlled arousal stimulus, we quantitatively measured the ability of such a stimulus to prevent dexmedetomidine loss of righting reflex in two inbred strains of mice (C57BL/6 and 129X1). We found that whereas the C57BL/6 strain required a strong stimulus to prevent dexmedetomidine-induced hypnosis, the 129X1 strain stayed awake even with minimal stimuli. Remarkably, this could be calibrated as a simple threshold trait, i.e. a binary ‘yes–no’ response, which after crossing the two mouse strains behaved as a dominant-like trait. We carried out a genome-wide linkage analysis on the F₂ progeny to determine if the ability of a stimulus to prevent dexmedetomidine hypnosis could be mapped to one or more chromosomal regions. We identified a locus on chromosome 4 with an associated Logarithm of Odds score exceeding the pre-established threshold level. These results show that complex traits, such as the ability of a stimulus to reverse drug-induced hypnosis, may have precise genetic determinants.

Securing the data economy: translating privacy and enacting security in the development of DataSHIELD

Contemporary bioscience is seeing the emergence of a new data economy: with data as its fundamental unit of exchange. While sharing data within this new 'economy' provides many potential advantages, the sharing of individual data raises important social and ethical concerns. We examine ongoing development of one technology, DataSHIELD, which appears to elide privacy concerns about sharing data by enabling shared analysis while not actually sharing any individual-level data. We combine presentation of the development of DataSHIELD with presentation of an ethnographic study of a workshop to test the technology. DataSHIELD produced an application of the norm of privacy that was practical, flexible and operationalizable in researchers' everyday activities, and one which fulfilled the requirements of ethics committees. We demonstrated that an analysis run via DataSHIELD could precisely replicate results produced by a standard analysis where all data are physically pooled and analyzed together. In developing DataSHIELD, the ethical concept of privacy was transformed into an issue of security. Development of DataSHIELD was based on social practices as well as scientific and ethical motivations. Therefore, the 'success' of DataSHIELD would, likewise, be dependent on more than just the mathematics and the security of the technology.

Navigating the perfect [data] storm

Bioscience has recently undergone a series of knowledge-based and technological revolutions. A critical consequence has been increasing recognition of the need to invest in infrastructure. Good access to data (and samples) from multiple studies is axiomatic to the value of this infrastructure. Access must be streamlined, secure, and based upon transparent and ‘fair’ decision making. It must be clear who has created and who has used which data. Ethico-legal policies and guidelines, which reflect dominant local cultural and societal norms, must take account of the increasingly global nature of bioscience research. A robust data infrastructure must also be attentive to the translational aims and social impact of its knowledge generation. In order to maintain the trust of its constituency – the general public as well as professional, political, commercial stakeholders – it must develop mechanisms to take account of all of these perspectives. These considerations form the basis of an emerging data economy. Building on extant achievements and pursuing the ideas outlined here could revolutionise the way we use and manage large-scale data. They have critical implications for biomedical and public health research communities and will be of central relevance for healthcare managers and policy makers, governments and industry. However, if the major challenges are to be met we must continue to invest,both nationally and internationally, in developing the cooperative infrastructures that provide a complementary foil to competitive resourcing mechanisms that drive hypothesis-driven science.

Immunohistochemical evidence of Muc1 expression during rat embryonic development

During embryonic development, studies on mouse and human embryos have established that Muc1/MUC1 expression coincides with the onset of epithelial sheet and glandular formation. This study aimed therefore at evaluating the temporal and spatial expression of Muc1 at different stages of rat development. In this report, 80 animals were included: 64 rat foetuses at 13, 14, 15, 16, 17, 18, 19 and 20 days of gestation from pregnant females (WKAH/Hok), 8 embryos each stage. Standard immunohistochemistry was performed using anti-MUC1 cytoplasmic tail polyclonal antibody (CT33). The reaction was considered positive when more than 5% of the cells were stained; reaction patterns were: L = linear, membrane, C = cytoplasmic and M = mixed; nuclear staining was also recorded. Intensity was graded as negative (−), low (+), moderate (++) and strong (+++). Muc1 expression was observed with a low intensity on 13th day (13 D) in the stomach, lung and kidney; at 14 d, small intestine and pancreas were also reactive; at 16 D, liver and esophagus and at 18 D, trachea and salivary glands. During the development, intensity increased while the pattern of expression changed: at the first days of gestation, it was predominantly linear and apical while during further development an increase in cytoplasmic expression was observed. Trachea, stomach, kidney and lung epithelia were the more reactive tissues. In specimens belonging to neonates and adults, all tissues analyzed showed similar Muc1 expression. The findings of this study assess that Muc1 is highly expressed in the epithelial rat embryonic development.

[Investigation of potential risk factors for Salmonella enterica subsp enterica serotype Napoli: a nested case-control study in Lombardia region]

Enter-net surveillance system has detected the re-emergence of Salmonella enterica subsp enterica serotype Napoli (S. Napoli) since 2002. Preliminary data show that food vehicle could not be the only one implicated in the transmission of this serotype. A nested case-control study has been conducted using data form a prospective cohort: for each salmonellosis notification in Lombardia from May 2004 to December 2005 an ad hoc epidemiological investigation has been performed. Cases have been defined as subjects affected by salmonellosis with a positive faecal sample for Salmonella serotype Napoli and controls as subjects affected by salmonellosis with a positive faecal sample for Salmonella serotype not Napoli. Among 2185 salmonellosis notifications collected by 12 of 15 Local Health Authorities, we identified 67 cases and 867 controls. Infection due to S. Napoli were significantly more common among subjects with exposure to surface water (adjusted Odds Ratio (OR) = 3,82; 95% Confidence Interval (C.I.)=1,03-14,19), to domestic animals (adjusted OR = 3,22; 95% C.I. = 1,28-8,10) and among person who practice activities connected to surface water (adjusted OR 3,88; 95% C.I.=1,15-13,05) compared to subjects not exposed to these factors. Hyperendemia of S. Napoli could be attributable to an animal reservoir not yet identified: surface water contamination may be a direct (waterborne infection) or indirect (foodborne infection) vehicle for transmission of S. Napoli. behaviour. Regarding the relations of the neuroendocrine parameters and driving behaviour, positive correlations were observed between dopamine levels and frequency of driving violations while a negative relationship was found between adrenaline levels and frequency of driving errors. In conclusion the identification of psycho-physiological variables related to driving risky behaviour might be a useful instrument to design traffic safety programs tailored to high risk subjects.

Effects of intra-accumbens NMDA and AMPA receptor antagonists on short-term spatial learning in the Morris water maze task

Glutamatergic transmission within the nucleus accumbens (Nac) is considered to subserve the transfer of different types of information from the cortical and limbic regions. In particular, it has been suggested that glutamatergic afferences from the hippocampus and the prefrontal cortex provide the main source of contextual information to the Nac. Accordingly, several authors have demonstrated that the blockade of glutamate receptors within the Nac impairs various spatial tasks. However, the exact role of the different classes of glutamate receptors within the Nac in short-term spatial memory is still not clear. In this study we investigated the involvement of two major classes of glutamate receptors, NMDA and AMPA receptors, within the Nac in the acquisition of spatial information, using the Morris water maze task. Focal injections of the NMDA antagonist, AP-5 (0.1 and 0.15 microg/side), and the AMPA antagonist, DNQX (0.005, 0.01 microg/side), were performed before a massed training phase, and mice were tested for retention immediately after. NMDA and AMPA receptor blockade induced no effect during training. On the contrary, injection of the two glutamatergic antagonists impaired spatial localization during the probe test. These data demonstrate an involvement of the Nac in short-term spatial learning. Moreover, they prove that within this structure the short-term processing of spatial information needs the activation of both NMDA and AMPA receptors.