PubMed Health⌕ Search

Biomedical subjects

Nigel Miller

Publications and source records attributed to Nigel Miller.

7 recordsLinked to original sources

Molecular and electrophysiological characterization of transient receptor potential ion channels in the primary murine megakaryocyte.

The molecular identity of platelet Ca(2+) entry pathways is controversial. Furthermore, the extent to which Ca(2+)-permeable ion channels are functional in these tiny, anucleate cells is difficult to assess by direct electrophysiological measurements. Recent work has highlighted how the primary megakaryocyte represents a bona fide surrogate for studies of platelet signalling, including patch clamp recordings of ionic conductances. We have now screened for all known members of the transient receptor potential (TRP) family of non-selective cation channels in murine megakaryocytes following individual selection of these rare marrow cells using glass micropipettes. RT-PCR detected messages for TRPC6 and TRPC1, which have been reported in platelets and megakaryocytic cell lines, and TRPM1, TRPM2 and TRPM7, which to date have not been demonstrated in cells of megakaryocytic/platelet lineage. Electrophysiological recordings demonstrated the presence of functional TRPM7, a constitutively active cation channel sensitive to intracellular Mg(2+), and TRPM2, an ADP-ribose-dependent cation channel activated by oxidative stress. In addition, the electrophysiological and pharmacological properties of the non-selective cation channels stimulated by the physiological agonist ADP are consistent with a major role for TRPC6 in this G-protein-coupled receptor-dependent Ca(2+) influx pathway. This study defines for the first time the principal TRP channels within the primary megakaryocyte, which represent candidates for Ca(2+) influx pathways activated by a diverse range of stimuli in the platelet and megakaryocyte.

Animals↗

Health-seeking behaviour and rural/urban variation in Kazakhstan.

This paper seeks to analyse the findings of an extensive household survey, uncovering interesting evidence of variation in health-seeking behaviour across rural and urban areas due, it is suggested, to differences in real costs, quality of care, and perceptions of the value of health and health care. It is shown that, ceteris paribus, urban households in Kazakhstan are more likely to consult, to be admitted to hospital, to report illness, and will spend relatively more on health care. The data suggest the need for further qualitative study into the factors underlying these patterns leading to strategies to increase the quality, acceptability and affordability of rural health services. This is important given the decline in health indicators such as life expectancy in Kazakhstan and the increased burden on households of funding health care in a time of economic insecurity and deterioration of public services.

Adult↗