A longitudinal study of the control of renal and uterine hemodynamic changes of pregnancy.

We have determined the sequence and extent of maternal renal and uterine adaptation to pregnancy and examined the role of hormonal factors in their regulation. Renal bipolar diameter (RBD), renal artery resistance index (RARI), uterine artery pulsatility index (UAPI), and plasma relaxin, human chorionic gonadotropin (hCG), progesterone, estradiol, urea, and creatinine were measured longitudinally in women with normal spontaneous singleton pregnancies, in vitro fertilization (IVF) singleton pregnancies, ovum donation (OD) singleton pregnancies, and multiple pregnancies from prepregnancy to postpartum. There was a progressive increase in the RBD and the RARI and a decrease in the UAPI during pregnancy.

Local suppression of T cell responses by arginase-induced L-arginine depletion in nonhealing leishmaniasis.

The balance between T helper (Th) 1 and Th2 cell responses is a major determinant of the outcome of experimental leishmaniasis, but polarized Th1 or Th2 responses are not sufficient to account for healing or nonhealing. Here we show that high arginase activity, a hallmark of nonhealing disease, is primarily expressed locally at the site of pathology. The high arginase activity causes local depletion of L-arginine, which impairs the capacity of T cells in the lesion to proliferate and to produce interferon-gamma, while T cells in the local draining lymph nodes respond normally.

Mitochondrial dysfunction and the role of the non-specialist laboratory.

Each human cell contains at least 1,000 mitochondria, each containing several copies of mitochondrial DNA. This DNA is tiny compared with the nuclear genome, and its structure and products have been fully elucidated. Whilst oxidative phosphorylation depends on the polypeptides encoded by mitochondrial DNA, it also requires a huge number of nuclear DNA products.

Placenta as a link between amino acids, insulin-IGF axis, and low birth weight: evidence from twin studies.

Current evidence suggests that reduced placental transport of amino acids regulates fetal growth. We determined the association between fetal nutrition and the insulin-IGF axis by measuring the plasma concentrations of amino acids, insulin, IGF-I and IGF-binding protein-1 (IGFBP-1) in maternal and cord blood from gestational age-matched dichorionic (DC) twins with (n = 10) and without discordant birth weights (n = 10). In the growth-restricted (IUGR) twins, fetal concentrations of total essential (P < 0.