Collagen production in cardiac fibroblasts during inhibition of aminopeptidase B.

OBJECTIVE: To determine whether the aminopeptidase B inhibitor, arphamenine A, could affect collagen production and expression in control and TGF-ss1-treated cardiac fibroblasts. DESIGN AND METHODS: Cardiac fibroblasts from passage 2 from normal male adult rats were cultured to confluency and incubated with and without 600 pmol/l TGF-ss1 for 2 days in serum-free Dulbecco's modified Eagle's medium and then incubated with 100 mol/l arphamenine A for 1 day in this medium with added ascorbic acid, ss-aminopropionitrile and titriated proline. Soluble collagen was measured in the conditioned medium and non-soluble collagen in the cell layer. Aminopeptidase activity was estimated by spectrophotometric determination of the liberation of p-nitroaniline from alanine- or arginine-p-nitroanilide. Matrix metalloproteinase (MMP) and lysyl oxidase activity were assayed in the conditioned medium. A semi-quantitative reverse transcriptase- polymerase chain reaction was used to examine the expression of lysyl oxidase and collagen type I and III. RESULTS: Arphamenine A dose-dependently inhibited basal and TGF-ss1-stimulated aminopeptidase activity. Arphamenine A reduced soluble and non-soluble collagen production in control and TGF-ss1-treated cardiac fibroblasts, while it decreased collagen type I and III expression only in TGF-ss1-treated fibroblasts. Lysyl oxidase, MMP-1 and MMP-2 activity were inhibited by arphamenine A in the conditioned media of control and TGF-ss1-treated cardiac fibroblasts. CONCLUSIONS: Our data show that the specific aminopeptidase B inhibitor, arphamenine A, reduces collagen production in cardiac fibroblasts and that this reduction is accompanied by a pronounced inhibition of lysyl oxidase.

Pediatric residency training on domestic violence: a national survey.

OBJECTIVE: Between 3.3 and 10 million children witness domestic violence (DV) each year. These children are at risk for both emotional and behavioral problems. In 1998, the American Academy of Pediatrics issued guidelines for pediatricians to screen for DV and for residency programs to include DV education. Prior studies have assessed practicing pediatricians' DV screening habits. This study was designed to assess chief residents' attitudes and training regarding DV screening. METHODS: A 53-question survey regarding residents' attitudes and training surrounding DV was mailed to the chief residents of all 194 nonmilitary US pediatric residency programs. Descriptive and inferential analyses were performed. RESULTS: Sixty-eight percent of surveys were returned. Sixty-eight percent of respondents were female. Although 93% of chief residents felt that pediatricians should screen for DV, only 21% screen every patient. Only 24% agreed or strongly agreed that they felt experienced in handling DV cases. Although 60% of respondents say that they received 11 or more hours of residency training in how to handle child abuse, the majority (80%) received 4 hours or less of DV training. Seventy-one percent agreed or strongly agreed that pediatricians do not screen secondary to lack of training. CONCLUSIONS: Pediatric chief residents believe that DV is a significant pediatric health problem. However, screening practices are variable. Most chief residents feel that their training was not sufficient to make them comfortable screening for DV. Chief residents demonstrated openness to incorporating DV training into their programs, indicating a positive environment for DV curricula.