OBJECTIVES

To compare tympanostomy tube insertion for children with otitis media in 2002 with the recommendations of two sets of expert guidelines.

DESIGN

Retrospective cohort study.

SETTING

New York metropolitan area practices associated with five diverse hospitals.

PARTICIPANTS

682 of 1046 children who received tympanostomy tubes in the five hospitals for whom charts from the hospital, primary care physician, and otolaryngologist could be accessed.

RESULTS

The mean age was 3.8 years. On average, children with acute otitis media had fewer than four infections in the year before surgery. Children with otitis media with effusion had less than 30 consecutive days of effusion at the time of surgery. Concordance with recommendations was very low: 30.3% (n=207) of all tympanostomies were concordant with the explicit criteria developed for this study and 7.5% (n=13) with the 1994 guideline from the American Academy of Pediatrics, American Academy of Family Medicine, and American Academy of Otolaryngology-Head and Neck Surgery. Children who had previously had tympanostomy tube surgery, who were having a concomitant procedure, or who had "at risk conditions" were more likely to be discordant.

CONCLUSIONS

A significant majority of tympanostomy tube insertions in the largest and most populous metropolitan area in the United States were inappropriate according to the explicit criteria and not recommended according to both guidelines. Regardless of whether current practice represents a substantial overuse of surgery or the guidelines are overly restrictive, the persistent discrepancy between guidelines and practice cannot be good for children or for people interested in improving their health care.

We examined a novel human feeder cell layer of mesenchymal stem cells harvested from human adipose tissues. Gene expression analyses and colony-forming assay with human primary epithelial cells showed that the adipose tissue-derived mesenchymal stem cells produced various factors to support epithelial stem/progenitor maintenance and cell growth. Using the mesenchymal stem cells as novel feeder layers, transplantable epithelial cell sheets could be effectively generated ex vivo on temperature-responsive cell-culture surfaces.

INTRODUCTION

Myxomatous mitral valve "degeneration" with prolapse (MVP) is the most frequent form of nonischemic mitral valve disease. In myxomatous valves, interstitial cells express extracellular matrix-degrading enzymes and it has been postulated that matrix metalloproteinases (MMPs) contribute to these changes.

METHODS

We generated mice with cardiac-specific expression of constitutively active MMP-2 under the control of the alpha-myosin heavy chain promoter.

RESULTS

These mice are normal at 4-6 months of age; at 12-14 months the mitral valves and chordae tendineae exhibit severe myxomatous change with echocardiographic MVP. Myxomatous change was also evident to a lesser extent in the aortic valves. Myxomatous changes were heterogeneous and limited to the left side of the heart with major disorganization of collagen bundles within the lamina fibrosa. Alcian blue/PAS-stained valves revealed massive accumulation of acidic glycosoaminoglycans within the lamina spongiosa, consistent with valvular interstitial cell differentiation to a chondrocytic phenotype. Cells with the histologic features of hypertrophied chondrocytes were found within the chordae tendineae and the tips of the mitral papillary muscles.

CONCLUSION

This report demonstrates that increased activity of a single enzyme, MMP-2, within a transgenic context reproduces many of the features of the human MVP syndrome. The cardiac-specific MMP-2 transgenic mouse potentially provides a unique experimental platform for the evaluation of nonsurgical therapies based on the underlying pathophysiology of this disease.

BACKGROUND

Studies in persons without HIV infection have compared adipose tissue measured by dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI), but no such study has been conducted in HIV-infected (HIV+) subjects, who have a high prevalence of regional fat loss.

OBJECTIVE

We compared DXA- with MRI-measured trunk, leg, arm, and total fat in HIV+ and control subjects.

DESIGN

A cross-sectional analysis was conducted in 877 HIV+ subjects and 260 control subjects in FRAM (Study of Fat Redistribution and Metabolic Change in HIV Infection), stratified by sex and HIV status.

RESULTS

Univariate associations of DXA with MRI were strongest for total and trunk fat (r > or = 0.92) and slightly weaker for leg (r > or = 0.87) and arm (r > or = 0.71) fat. The average estimated limb fat was substantially greater for DXA than for MRI for HIV+ and control men and women (all P < 0.0001). Less of a difference was observed in trunk fat measured by DXA and MRI, but the difference was still statistically significant (P < 0.0001). Bland-Altman plots showed increasing differences and variability. Greater average limb fat in control and HIV+ subjects (both P < 0.0001) was associated with greater differences between DXA and MRI measurements. Because the control subjects had more limb fat than did the HIV+ subjects, greater amounts of fat were measured by DXA than by MRI when control subjects were compared with HIV+ subjects. More HIV+ subjects had leg fat in the bottom decile of the control subjects by DXA than by MRI (P < 0.0001).

CONCLUSIONS

Although DXA- and MRI-measured adipose tissue depots correlate strongly in HIV+ and control subjects, differences increase as average fat increases, particularly for limb fat. DXA may estimate a higher prevalence of peripheral lipoatrophy than does MRI in HIV+ subjects.