Medical Research Council

About: Medical Research Council is a government organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Malaria. The organization has 16430 authors who have published 19150 publications receiving 1475494 citations.

A paradox in the lateralisation of the visual evoked response

Abstract: THE average evoked response in man to stimulation of the visual field with a reversing checkerboard pattern and recorded from the scalp over the occipital region has a waveform which is consistent both within and between subjects. The most characteristic feature for full-field stimulation is a major positive component at about 100 ms which is recorded maximally 5 cm above the inion in the midline and is distributed fairly symmetrically over both sides of the head (Fig. 1). The pathways from the retina to the visual cortex undergo partial decussation in the chiasma, so that information presented to the left half of the visual field passes to the right hemisphere, whereas the left hemisphere receives signals from the right half of the visual field. Consequently, it might be predicted that stimulation of one half field will produce an evoked response which is maximal over the contralateral hemisphere. The data presented here show that, contrary to this prediction, the maximal response occurs at the scalp electrodes situated over the hemisphere ipsilateral to the field stimulated.

Species-specific transcription in mice carrying human chromosome 21.

Abstract: Homologous sets of transcription factors direct conserved tissue-specific gene expression, yet transcription factor-binding events diverge rapidly between closely related species. We used hepatocytes from an aneuploid mouse strain carrying human chromosome 21 to determine, on a chromosomal scale, whether interspecies differences in transcriptional regulation are primarily directed by human genetic sequence or mouse nuclear environment. Virtually all transcription factor-binding locations, landmarks of transcription initiation, and the resulting gene expression observed in human hepatocytes were recapitulated across the entire human chromosome 21 in the mouse hepatocyte nucleus. Thus, in homologous tissues, genetic sequence is largely responsible for directing transcriptional programs; interspecies differences in epigenetic machinery, cellular environment, and transcription factors themselves play secondary roles.

Mycobacterium tuberculosis lineage 4 comprises globally distributed and geographically restricted sublineages.

Abstract: Generalist and specialist species differ in the breadth of their ecological niches Little is known about the niche width of obligate human pathogens Here we analyzed a global collection of Mycobacterium tuberculosis lineage 4 clinical isolates, the most geographically widespread cause of human tuberculosis We show that lineage 4 comprises globally distributed and geographically restricted sublineages, suggesting a distinction between generalists and specialists Population genomic analyses showed that, whereas the majority of human T cell epitopes were conserved in all sublineages, the proportion of variable epitopes was higher in generalists Our data further support a European origin for the most common generalist sublineage Hence, the global success of lineage 4 reflects distinct strategies adopted by different sublineages and the influence of human migration