Parathyroid hormone-related protein as a renal regulating factor. From vessels to glomeruli and tubular epithelium.

Parathyroid hormone (PTH) and PTH-related protein (PTHrP) produce similar biological effects through the PTH/PTHrP receptor. Less is known about the physiological role of PTHrP, which was first identified as the agent of the humoral hypercalcemia of malignancy. Despite the widespread production of PTHrP in healthy individuals, the concentration of the protein is below the detectable limit of current assays, suggesting that PTHrP normally functions locally in an autocrine or paracrine manner. Thus, some differences in their biological activities have been described and they may be related to the presence of different receptors. In this regard, a second receptor that binds selectively to PTH has also been found. Recent studies have demonstrated the expression of both PTH/PTHrP receptor and protein in the renal glomeruli. Moreover, there are convincing data that support a direct role of PTH and PTHrP in modulating renal blood flow and glomerular filtration rate. This multifunctional protein, PTHrP, also has a proliferative effect on both glomerular mesangial cells and tubular epithelial cells. Increases in the expression of PTHrP have been observed in several experimental models of nephropathies, suggesting that PTHrP upregulation is a common event associated with the mechanism of renal injury and repair.

The beneficial effects of weekly low-dose vitamin A supplementation on acute lower respiratory infections and diarrhea in Ecuadorian children.

BACKGROUND: Previous studies of large-dose vitamin A supplementation on respiratory morbidity have produced conflicting results in a variety of populations. The influence of malnutrition has not been examined in the majority of these trials. We hypothesized that weekly low-dose vitamin A supplementation would prevent respiratory and diarrheal disease morbidity and that malnutrition might influence the efficacy of vitamin A supplementation. METHODS: In a randomized, double-blind, placebo-controlled field trial of 400 children, 6 to 36 months of age in a high Andean urban slum, half of the children received 10 000 IU of vitamin A weekly and half received placebo for 40 weeks. Children were visited weekly at home by physicians and assessed for acute diarrheal disease and acute respiratory infections. RESULTS: Acute diarrheal disease and acute respiratory infection did not differ globally or by severity between supplement-treated and placebo groups. However, the incidence of acute lower respiratory infection (ALRI) was significantly lower in underweight (weight-for-age z score [WAZ] <-2 SD) supplement-treated children than in underweight children on placebo (8.5 vs 22.3 per 10(3) child-weeks; rate ratio: 0.38 [95% CI: 0.17-0.85]). ALRI incidence was significantly higher in normal-weight (WAZ >-2 SD) supplement-treated children than in normal-weight children on placebo (9.8 vs 4.4 per 10(3) child-weeks; rate ratio: 2.21 [95% CI: 1.24-3.93]). By logistic regression analysis the risk of ALRI was lower in underweight supplement-treated children than in underweight children on placebo (point estimate 0.148 [95% CI: 0.034-0.634]). In contrast, risk of ALRI was higher in normal-weight supplement-treated children (WAZ >-1 SD to mean) than in normal-weight children on placebo in the same WAZ stratum (point estimate: 2.51 [95% CI: 1.24-5.05]). The risk of severe diarrhea was lower in supplement-treated children 18 to 23 months of age than in children on placebo in this age group (point estimate: 0.26 [95% CI: 0.06-1.00]). CONCLUSIONS: Weekly low-dose (10 000 IU) vitamin A supplementation in a region of subclinical deficiency protected underweight children from ALRI and paradoxically increased ALRI in normal children with body weight over -1 SD. Protection from severe diarrhea was consistent with previous trials. Additional research is warranted to delineate potential beneficial and detrimental interactions between nutritional status and vitamin A supplementation regarding ALRI.

A survey of nurses' knowledge, opinions, and reported uses of the Body Substance Isolation system.

The Body Substance Isolation (BSI) system was implemented at the University of California San Diego Medical Center in May 1987. About 2 years later, an evaluation was done of the long-term effects of BSI education and training on the knowledge, attitudes, and reported behaviors of nursing personnel. In June 1989, a questionnaire was sent to 600 nursing personnel, including all 100 nurses in the 20-bed surgical intensive care unit, all 66 charge nurses, and a random sample (434) of the remaining nursing staff (about 1000). Results from the 190 respondents (a response rate of 32%) indicated an understanding of the two purposes of BSI: (1) to reduce nosocomial infection risks to patients and (2) to reduce health care workers' risks of acquiring infections from patients. Over half of the respondents reported handling more than 11 needles per day and nearly half reported recapping contaminated needles two-handed "sometimes or often." Only 54% of the respondents reported they had received hepatitis B vaccine. Although more than two-thirds of the respondents had worked at the University of California San Diego Medical Center during the entire BSI system training, implementation, and follow-up period, there is still room for improvement in knowledge and use of the system, including issues related to the safe handling of sharps.