Paracrine signalling by pancreatic δ cells determines the glycaemic set point in mice.

While pancreatic β and α cells are considered the main drivers of blood glucose homeostasis through insulin and glucagon secretion, the contribution of δ cells and somatostatin (SST) secretion to glucose homeostasis remains unresolved. Here we provide a quantitative assessment of the physiological contribution of δ cells to the glycaemic set point in mice. Employing three orthogonal mouse models to remove SST signalling within the pancreas or transplanted islets, we demonstrate that ablating δ cells or SST leads to a sustained decrease in the glycaemic set point.

Human exposure to heavy metals in the vicinity of Portuguese solid waste incinerators--Part 2: biomonitoring of lead in maternal and umbilical cord blood.

As part of environmental health surveillance programs related to solid waste incinerators located near Lisbon and on Madeira Island, human biomonitoring projects have been implemented in Portugal, some of them focused on cross-sectional surveys of heavy metals in blood. One of the general aims of these programs is to provide Portuguese data on the extent and pattern of human exposure to the pollutants potentially released in the stack gases from the incinerators, namely heavy metals. The present investigation reports information specifically on blood lead levels of newborn-mother pairs living in the vicinity of the incinerators under study, as well as of statistically similar participants living outside the exposed area.

Human exposure to heavy metals in the vicinity of Portuguese solid waste incinerators--Part 3: biomonitoring of Pb in blood of children under the age of 6 years.

As a part of environmental health surveillance programs related to Portuguese solid waste incinerators (SWI), two biomonitoring projects have been established to investigate additional exposure to lead in children under the age of 6 years living in the vicinity of those facilities. The above-mentioned programs, being the only ones in the country that integrate systematic observations on human exposure to heavy metals, have to provide systematic data from Portuguese regions on the extent and pattern of human exposure to heavy metals, namely to lead. The present paper is the third of a series of papers prepared to accomplish that objective in regards to lead exposure as evaluated by measuring lead levels in children under the age of 6 years.

Quantification of urinary chorionic gonadotropin in spontaneous abortion of pre-clinically recognized pregnancy: method development and analytical validation.

Determination of environmental impacts on reproductive health and specifically on the incidence of early spontaneous abortion requires accurate estimates of the latter. This negative reproductive outcome can be detected by the pattern of elevation and decline of human chorionic gonadotropin (hCG) levels near and shortly beyond the expected time of implantation, requiring daily biomonitoring of hCG levels during the relevant period of the menstrual cycle. Prospective pregnancy studies to assess effects of potentially toxic exposures on human reproductive outcomes can involve up to three menstrual cycles and a huge number of samples in each, for the quantification of the inherently very low hCG levels usually can be determined only in serum.

Human exposure to heavy metals in the vicinity of Portuguese solid waste incinerators--Part 1: biomonitoring of Pb, Cd and Hg in blood of the general population.

Human exposure to heavy metals makes it necessary to monitor these elements in the human body if the objective is to relate heavy metal exposure to adverse health effects. In Portugal, biomonitoring projects on heavy metals are being carried out on people living in the vicinity of solid waste incinerators. The projects are being developed in the ambit of two environmental health surveillance programs related to solid waste incineration facilities, one near Lisbon and the other on Madeira Island, that have the main objective of guaranteeing the safeguard of public health in relation to the potential negative impact of incineration processes on human health.