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It has been stated that cyclosporin and nifedipine produce gingival overgrowth. However, the specific pathogenic mechanism remains uncertain. We used an experimental rat model to test the hypothesis that changes in collagen metabolism and numbers of gingival blood vessels are not mediated by intracellular calcium concentration (ratiometric Fura-2 AM measurement) in gingival fibroblasts. In the cyclosporin group, both width (364.2 ± 67.5 μm) and microvessel density (number of vessels/mm2, stained with anti-CD34 antibody) (41.6 ± 5.1) of gingiva were statistically different when compared with those in the control group (width = 184.3 ± 35.2 μm, microvessel density = 19.6 ± 2.4). The nifedipine group showed the highest content of collagen (proportion of total stroma occupied by collagen, stained with Picro-Mallory) (nifedipine group = 66.3 ± 9.4, cyclosporin group = 55.2 ± 7.9, control group = 30.1 ± 10.2). Freshly cultured fibroblasts from the cyclosporin group exhibited higher ratiometric values of fluorescence than did both the control and nifedipine groups (p = 0.03). Our results support the hypothesis that changes in gingival collagen metabolism are not mediated by calcium intracellular oscillations.

Demonstrations include electroplating copper, Fehling's test, the silver mirror (Ag+ + tartrate), insoluble silver salts, photo-film + hypo, hypo fixer + silver coin, and a solution of gold in aqua-regia.

Demonstrations include insoluble carbonates, decomposing of carbonates by heating, volume of CO2 from carbonates and bicarbonates, sensitive test for CO3=, breath forming CO3= and HCO3=, and CO2 in...

Demonstrations include rising mothballs with CO2, dry ice into limewater, and producing school colors: CO2 changing pH.

Demonstration include an ammonia generator; ammonia diffusion throughout a rubber balloon; ammonium chloride smoke; and secret writing using HgNH2Cl + Hg.

Demonstrations include nitric acid + H2S, sodium nitrate + carbon, fire-writing with KNO3, nitrate ring test, nitrate versus nitrite, and micro-analysis for nitrogen compounds.

Demonstrations include the stability of hydroxides (Na, Ca, Ba), carbonates (Na, Ca, Cu), and nitrates (Ca, Cu, Ag); and sequestration.

Demonstrations include birthstones, the preparation of Al from Fe, amphoteric Al(OH)3, aluminon test for Al, crude vs pure ceric salts, ceric sulfate + Fe++, and ceric sulfate + hydrogen peroxide.

Demonstrations include conductivity using a meter, conductivity of HCl in water versus in toluene, conductivity of HCl in water versus in benzene, acids plus zinc, indicators with acids and bases (H3O+ and OH-), rate of reaction and acid strengths, colors of ions, and color of cobalt ion and a cobalt complex.