Vasopressin induces dopamine release and cyclic AMP efflux from the brain of water-deprived rats: inhibitory effect of vasopressin V2 receptor-mediated phosphorylation

MR imaging is the best noninvasive method for the evaluation of articular cartilage. Recent studies have clarified the MR appearance of normal articular cartilage and proven that MR imaging can detect chondral lesions with high accuracy. Quantitative imaging holds promise for the accurate determination of cartilage volumes and thickness measurements, as well as the ability to detect early chondral degeneration and biochemical changes before gross morphologic changes occur.     

Quantification of the nucleocytoplasmic distribution of wild type and modified proteins using confocal microscopy: interaction between 90-kDa heat shock protein (Hsp90 alpha) and glucocorticosteroid receptor (GR)

Elastin is a major protein component of the vascular wall and is responsible for its unusual elastic properties. Polymers of its repeating VPGVG sequences have been synthesised and shown to exhibit an inverse temperature transition where, as temperature rises, the polymer collapses from an extended chain to a beta-spiral structure with three VPGVG units per turn, each pentamer adopting a type II beta-turn conformation. These studies, however, have not established whether the temperature-driven conformational change is an intrinsic property of the individual pentameric sequences or a global, co-operative effect of many pentamers within the beta-spiral structure. Here, we examine by circular dichroism the behaviour of elastin-like peptides (VPGVG)n, where n varies between 1 and 5. Remarkably, we find that all lengths of peptide undergo an extended left and right arrow beta-turn transition with increasing temperature, suggesting that the induction of the beta-spiral occurs at the level of single pentameric units. The origin of this effect is a positive DeltaS term for the transition. At 35 degreesC, the average transition midpoint temperature, the value of TDeltaS is about 15 kcal mol-1. With larger oligomers (n=3), there is only a modest rise in DeltaS, suggesting that the dominant entropic effect resides within the monomer and that interactions between these units make only a small contribution to the energetics of the transition. Charges at the termini, and residue replacements or additions, regulate the transitions for the short peptides in a manner similar to that observed for the longer polymers. The behaviour of the same peptides in trifluoroethanol and SDS solutions is consistent with formation of the beta-turn being driven by interactions between non-polar groups. The significance of this behaviour for the rational design of temperature-induced responses in proteins is discussed.     

Validation of multifrequency bioelectrical impedance analysis in monitoring fluid balance in healthy elderly subjects

BACKGROUND: Multifrequency Bioelectrical Impedance Analysis (MFBIA) is a novel method to assess body composition in elderly subjects. However, it is unclear whether MFBIA can detect changes in body water compartments in elders. We aimed to determine the within-subject variability of MFBIA and the responsiveness to a diuretic intervention in aged subjects with a stable fluid balance. METHODS: We selected 12 healthy active elderly subjects (5 male, 7 female) with a mean age of 75 years. Total body water and extracellular fluid (ECF) were measured by deuterium oxide- and potassium bromide-dilution techniques. Within-subject variability in total body MFBIA was assessed by performing four measurements at 1, 5, 50, and 100 kHz within a 2-month period. Subsequently, responsiveness of MFBIA to the ECF loss caused by oral administration of 40 mg of furosemide was determined. RESULTS: Within-subject variability in MFBIA at 1, 5, 50, and 100 kHz expressed as standard deviations was 21, 19, 14, and 14 Ohm (omega), respectively. Furosemide caused a mean weight loss of 1.8 +/- 0.6 kg, which resulted in significant increases in impedance of 57 +/- 24 omega at 1 kHz and 37 +/- 12 omega at 100 kHz (p < .001). The responsiveness of MFBIA for the diuretic intervention was best at 5 kHz (responsiveness index = 1.98). CONCLUSIONS: Within-subject variability of MFBIA was small in healthy elderly subjects with stable fluid balance. Responsiveness of MFBIA to 9% furosemide-induced ECF loss was excellent. These data support the necessity for further clinical assessment of the value of MFBIA in monitoring fluid balance in geriatric patients.     

Lack of evidence for inhibition of ovulation by aspirin in women

Prostaglandin synthetase inhibitors such as aspirin and indomethacin inhibit ovulation in experimental animals. The effect of therapeutic doses of aspirin on ovulation has been studied in 5 women. Ovulation, as assessed by measurements of urinary LH and plasma progesterone levels, basal body temperature and cervical mucus changes occured in all the control and treatment cycles. Serial sections of the corpora lutea failed to show any entrapped ova. The significance of finding a prostaglandin synthetase inhibitor which acts specifically at the ovarian level is discussed.     

A rapid semiquantitative Mg-urine-test suitable for field estimations of the magnesium status in ruminants

A semiquantitative Mg-urine-test suitable for field examination of the Mg-status in ruminants has been tested under practical conditions. Good agreement between the semiquantitative test and quantitative atomic absorption Mg-estimations was found. It is recommended always to examine urine from at least two-three animals in a herd to get a reliable picture of the Mg-status of the herd.     

Reproductive efficiency as a social indicator

An index of reproductive effiency (RE) is proposed as a social indicator that will meet the need to consider various forms of pregnancy wastage, to compare their relative costs, and to guide reproductive health policy accordingly. This article discusses conceptual and measurement aspects of RE. Conversion of wanted to unwanted pregnancies and the reverse, interpretation of abortion in relation to other pregnancy outcomes, defining the end point for the reproductive process and criteria for the events to be included as significant outcomes are conceptual issues. Measurement problems include: whether aggregation is justified, prospective and retrospective tracking of outcomes, record limitations, duplication of adversities in a single pregnancy, and selection of optimal rate for comparison. A measurement of RE for the entire United States based on the National Natality Survey of 1964-1966 is presented, showing 74.5 percent of pregnancies resulting in healthy liveborn infants. For those years, data on abortions could not be included. Within the group of reported pregnancy losses, the importance of congenital abnormalities and low-birth-weight babies is enhanced by application of economic weights based on associated medical care costs. Changing opportunities for birth timing, prenatal and infant care, and control of family size are social means of reducing adverse outcomes associated with teenage pregnancy and high-parity births, often found together with poverty. Successive increments in RE may be progressively more expensive to achieve, and cost effectiveness comparison will be necessary.