The major remaining challenge in the prevention of mother-to-child transmission is the reduction of the risk in settings where breast-feeding is common. This review gives an update on ongoing or planned antiretroviral intervention studies in resource-limited settings that are aimed at reducing the risk of mother-to-infant HIV transmission during lactation. These strategies include antiretroviral therapy given to the mother to reduce viral load in plasma and breast milk as well as antiretroviral regimens providing prophylaxis to uninfected infants during the period of breast-feeding. The rationale for the interventions based on animal models and human studies is described as well as the study designs of clinical trials. Potential risks and benefits of these interventions to mothers and infants are also highlighted. Laboratory studies nested within several of these trials will provide a better understanding of the pathogenesis of postnatal HIV transmission and its potential prevention using antiretroviral drugs.

Detection of breast cancer cells in human blood may provide early determination of metastasis, enabling aggressive treatment prior to detection by conventional radiographic methods. We developed a photoacoustic flowmetry system in which we irradiated breast cancer cells in suspension to simulate metastatic breast cancer cells derived from human blood. In order to provide optical discrimination between the breast cancer cells and lymphocytes, we attached antibody labeled latex microspheres and gold nanoparticles to breast cancer cells. The breast cancer cells were derived from an estrogen receptor (ER) positive cell line, MCF-7. The particles were conjugated to ER antibodies. We irradiated the cell suspension using the photoacoustic flowmeter consisting of a glass flow chamber with a piezoelectric sensor. We irradiated the suspension at 422 and 530 nm and solved a linear system of equations in two variables to separate the contribution of the photoacoustic wave from the breast cancer cells and possible erythrocytes that may be present in a patient blood draw. We found a detection threshold of 10 breast cancer cells using this flowmeter. Future optimization of the system may decrease the detection threshold to single breast cancer cells.

No abstract

No abstract

No abstract