Lung volume measurements in childhood.

Although less commonly used in clinical practice than spirometry, lung volume measurements are helpful in assessing progress and response to therapy in situations where lung volume is likely to be increased, as in asthma or cystic fibrosis, or reduced secondary to pulmonary hypoplasia, pulmonary fibrosis, or musculoskeletal abnormalities. Their contribution to research has been considerable. The techniques most commonly used are those of inert gas dilution on rebreathing, applicable to children of all ages but tending to under-record in the presence of gas trapping.

Expression of metalloproteinases from human retinal pigment epithelial cells and their effects on the hydraulic conductivity of Bruch's membrane.

Purpose: To evaluate the expression pattern of matrix metalloproteinases (MMPs) from retinal pigment epithelial (RPE) cells in culture, and to determine their ability to alter the transport properties of human Bruch's membrane.

Methods: Human RPE cells from either primary cultures or a cell line were maintained under culture conditions. At different time intervals after subculturing of cells the presence of MMPs in the bathing medium was determined by zymography.

Age-related alterations in the diffusional transport of amino acids across the human Bruch's-choroid complex.

Photoreceptor maintenance is dependent on effective delivery of nutrients from the choroidal circulation by way of the acellular Bruch's membrane and the retinal pigment epithelium. Aging of Bruch's membrane is associated with thickening, increased cross linking of fibers, and deposition of debris culminating in reduced porosity. The present study has investigated the effects of aging on the diffusional transport of eight amino acids across Bruch's membrane in 19 human donors.

Age-dependent variation in metalloproteinase activity of isolated human Bruch's membrane and choroid.

Purpose: To characterize and determine the effect of aging on the matrix metalloproteinase (MMP) component of the extracellular matrix-remodeling mechanism of isolated human Bruch's-choroid.

Methods: Immunohistochemical techniques and western blot analysis were used to detect and localize various members of the MMP family of proteolytic enzymes in the Bruch's-choroid complex. Gelatin substrate zymography was used to detect and quantify the levels of MMP-2 and -9 in homogenates of Bruch's-choroid from both macular and peripheral regions of the human fundus.

Prenatal tests: how are women deciding?

Women offered prenatal tests should be given sufficient information to enable them to make an informed decision. We compared the decision-making of 261 women who underwent serum screening for Down syndrome with 63 who did not. A questionnaire completed at 16 weeks' gestation assessed systematic decision-making (the weighing up of pros and cons on the basis of information presented), knowledge, anxiety and demographic information.