Purity and enrichment of laser-microdissected midbrain dopamine neurons

The ability to microdissect individual cells from the nervous system has enormous potential, as it can allow for the study of gene expression in phenotypically identified cells. However, if the resultant gene expression profiles are to be accurately ascribed, it is necessary to determine the extent of contamination by nontarget cells in the microdissected sample. Here, we show that midbrain dopamine neurons can be laser-microdissected to a high degree of enrichment and purity. The average enrichment for tyrosine hydroxylase (TH) gene expression in the microdissected sample relative to midbrain sections was approximately 200-fold. For the dopamine transporter (DAT) and the vesicular monoamine transporter type 2 (Vmat2), average enrichments were approximately 100- and 60-fold, respectively. Glutamic acid decarboxylase (Gad65) expression, a marker for GABAergic neurons, was several hundredfold lower than dopamine neuron-specific genes. Glial cell and glutamatergic neuron gene expression were not detected in microdissected samples. Additionally, SN and VTA dopamine neurons had significantly different expression levels of dopamine neuron-specific genes, which likely reflects functional differences between the two cell groups. This study demonstrates that it is possible to laser-microdissect dopamine neurons to a high degree of cell purity. Therefore gene expression profiles can be precisely attributed to the targeted microdissected cells.

Maternal hair selenium levels as a possible long-term nutritional indicator of recurrent pregnancy loss

BackgroundApproximately 1% of all couples trying to conceive will suffer from recurrent pregnancy loss (RPL). Nutritional deficiencies have been postulated as a possible cause of RPL and in particular, selenium deficiency has been associated with reproductive failure in animal studies and more recently, in some human studies. This study was undertaken to assess the maternal hair selenium levels in women with RPL without an identified cause and to compare these results with those of women with successful reproductive histories.MethodsTwenty four patients with RPL and twenty four control subjects with at least one successful pregnancy and no pregnancy failures, who were matched for age and ethnicity, were recruited. A questionnaire was completed, which included demographic and social information and a dietary history. Hair samples were collected and analyzed for selenium content by inductively coupled plasma mass spectrometry.ResultsThe control subjects had a higher mean income and had completed more years of education compared with the RPL patients. There was no significant difference in the intake of selenium rich foods between the 2 groups. The patients, however, consumed significantly more fruit, cheese, potatoes and chocolate than the controls. The median (range) selenium content was 0.80 ppm (0.19-4.15) and 0.68 ppm (0.43-3.76) in patients and controls respectively (Mann Whitney U test 209.5 p = 0.74).ConclusionsWhile there were significant differences in the 2 groups with regard to resources, education and diet our results show that hair selenium concentrations and dietary selenium intake, were similar in the two groups. Both groups had low levels of this important element.

When nutritional guidelines and life collide: family fruit and vegetable socialisation practices in low socioeconomic communities

Parents play a critical role in promoting fruit and vegetable consumption, for eating patterns established early in life tend to persist into adulthood. Despite this, the factors that facilitate or inhibit parents’ capacity to socialise fruit and vegetable consumption into their children’s daily diets remain poorly defined. Thirty-eight semi-structured interviews with residents, allied healthcare professionals, community leaders, community programme leaders and a local government leader living or working in two low socioeconomic suburbs were consequently conducted to ascertain factors exogenous and endogenous to the family unit that shaped parental food socialisation practices. Budgetary and time constraints emerged as exogenous factors that constrained fruit and vegetable socialisation. Constraining effects were also found for a range of endogenous factors, including commensal experiences, children’s food fussiness and the feeding styles employed by parents. As such, while many caregivers may wish to socialise fruit and vegetable consumption into their children’s daily diets, their capacity to do so is often inhibited by factors beyond their volitional control. Failure to take heed of these factors could therefore result in the development of social marketing campaigns that are ineffective at best or give rise to unintentionally harmful outcomes at worst.