Effects of gravity on proliferation and differentiation of adipose tissue-derived stem cells.

Recent studies have demonstrated that culturing stem cells under altered gravity conditions modulates their proliferation and differentiation. In the current study we focused on osteogenesis. In an attempt to induce high proliferation rates and low differentiation of adipose tissue-derived stem cells (AT-MSCs), we exposed them to simulated microgravity (sim-microg) and hypergravity. We used the random positioning machine (RPM) to simulate microg and the medium sized centrifuge for acceleration research (MidiCAR) for hypergravity. AT-MSCs from different origin (human and goat) seeded in OptiCells were housed in the RPM and MidiCAR and compared with suitable controls cultured under static conditions (1 g). The experiments lasted 7 or 14 days. We report data on AT-MSCs proliferation as DNA content, and on the expression of specific osteogenic markers (cbfa-1, alkaline phosphatase activity and Van Kossa staining).

[Surgical therapy for prosthetic heart valve endocarditis: immediate results and follow-up]. / Terapia chirurgica dell'endocardite su protesi valvolare cardiaca: risultati immediati e follow-up.

Between January 1980 and May 1990 17 patients underwent surgery for prosthetic valve endocarditis at Cardiosurgical Department of Bologna University. Ten patients were female and seven male, the average age was 33 years (range 19 to 67 years). The interval from valve replacement to onset of symptoms of prosthetic valve endocarditis was less than 2 months in 5 patients and longer than 2 months in 12 patients. Sixteen of 17 infected prostheses were mechanical and one biological. All patients were surgically treated and the infected prostheses replaced with new valve prostheses. The hospital mortality rate for early prosthetic valve endocarditis was 60%, for late endocarditis was 16.5%, global hospital mortality was 29.4%.