PubMed Health⌕ Search

Biomedical subjects

Giuseppe Spoto

Publications and source records attributed to Giuseppe Spoto.

23 records · Page 2Linked to original sources
PubMed2003

Aspartate aminotransferase activity in gingival crevicular fluid during orthodontic treatment. A controlled short-term longitudinal study.

BACKGROUND: During orthodontic tooth movement, the early response of periodontal tissues to mechanical stress involves an acute inflammatory response, with a sequence characterized by periods of activation, resorption, reversal, and formation in both tension and compression sites. This study used a longitudinal design to examine aspartate aminotransferase (AST) activity in gingival crevicular fluid (GCF) in order to assess whether AST in GCF has potential as a possible diagnostic aid to monitor tooth movement and tissue response during orthodontic treatment. METHODS: Eighteen patients (mean age, 16.1 years) participated in the study. An upper first molar from each patient undergoing treatment for distal movement served as the test tooth (TT), with its contralateral (CC) and antagonist (AC) first molars used as controls. The CC was included in the orthodontic appliance, but was not subjected to the orthodontic force; the AC was free from any orthodontic appliance. The GCF around the experimental teeth was collected from both mesial and distal tooth sites immediately before appliance activation, 1 hour after, and weekly over the following 4 weeks. Clinical gingival condition was evaluated at baseline and at the end of the experimental period. AST activity was determined spectrophotometrically at 30 degrees C, and the results were expressed as total AST activity (mU/sample). RESULTS: Throughout the experiment, AST levels were significantly elevated in all sites from the TT and CC groups compared to the AC group where, conversely, AST activity remained at the baseline level. However, enzyme levels in the TT group were significantly greater than in the CCs at tension sites on day 14, and in compression sites on days 7 and 14. Moreover, AST activity from the TT group was significantly greater in compression sites than in tension sites on day 7; this was not observed for the CCs. CONCLUSIONS: Our results suggest that AST levels in GCF reflect the biological activity which occurs in the periodontium during controlled occlusal trauma and, therefore, should be further evaluated as a diagnostic tool for monitoring correct orthodontic tooth movement in clinical practice.

Adolescent↗
PubMed2002

Detecting past attempts to restore two important works of art.

Chemistry plays a fundamental role in the preservation of our heritage. Artistic and archaeological materials deteriorate over time due to their interaction with the environment, and human intervention can trigger unexpected deterioration pathways. Previous intervention can also sometimes obscure information regarding the original techniques or the materials used to execute the artwork. Our studies of past intervention and attempts to conserve the lunette of the church of Santa Maria la Vetere in Militello Val di Catania (Italy) and Donatello's carved marble panels of the pulpit of the Duomo of Prato (Italy) are discussed as two examples of how chemistry can provide guidance for conservators and fill gaps in the known life of works of art.

Journal Article↗
PubMed2002

Alkaline phosphatase activity in gingival crevicular fluid during human orthodontic tooth movement.

Bone remodeling that occurs during orthodontic tooth movement is a biologic process involving an acute inflammatory response in periodontal tissues. A sequence characterized by periods of activation, resorption, reversal, and formation has been recently described as occurring in both tension and compression tooth sites during orthodontic tooth movement. We used a longitudinal design to investigate alkaline phosphatase (ALP) activity in gingival crevicular fluid (GCF) to assess whether it can serve as a diagnostic aid in orthodontics. Sixteen patients (mean age, 15.5 years) participated in the study. The maxillary first molars under treatment served as the test teeth (TT) in each patient; in particular, 1 first molar was to be retracted and hence was considered the distalized molar (DM), whereas the contralateral molar (CM) was included in the fixed orthodontic appliance but was not subjected to the distal forces. The DM antagonist first molar (AM), free from any orthodontic appliance, was used as the baseline control. The GCF around the experimental teeth was harvested from mesial and distal tooth sites immediately before appliance activation, 1 hour after, and weekly over the following 4 weeks. The clinical gingival condition was evaluated at the baseline and at the end of the experimental term. ALP activity was determined spectrophotometrically at 30 degrees C, and the results were expressed as total ALP activity (mUnits/sample). GCF ALP activity was significantly elevated in the DMs and the CMs as compared with the AMs at 1, 2, 3, and 4 weeks; conversely, in the AMs, GCF ALP activity remained at baseline levels throughout the experiment. Moreover, the enzyme activity in the DMs was significantly greater than in the CMs. In the DMs, a significantly greater ALP activity was observed in sites of tension compared with sites of compression. This difference was not seen with the CMs, in which the enzyme activity increased to the same extent in tension and compression sites. These results suggest that ALP activity in GCF reflects the biologic activity in the periodontium during orthodontic movement and therefore should be further investigated as a diagnostic tool for monitoring orthodontic tooth movement in clinical practice.

Adolescent↗
PubMed2002

Nitric oxide production stimulated by the basic fibroblast growth factor requires the synthesis of ceramide.

Nitric oxide (NO) is an intracellular and intercellular mediator involved in the modulation of many physiologic and pathologic processes including the regulation of neoangiogenesis. We analyzed the effects of basic fibroblast growth factor (bFGF) on NO production in CHO-K1 cells and the intracellular mechanisms involved. bFGF induces NO production through activation of the endothelial NO synthase (eNOS), causing a subsequent increase in cGMP levels. In most systems, eNOS activation is a Ca(2+)-calmodulin-dependent process. In CHO-K1 cells, NO production by bFGF is Ca(2+) and MAP kinase independent, because it was not reverted by pretreatment with intracellular Ca(2+) chelators or MEK inhibitors. Translocation of the eNOS from the plasma membrane, where it is bound to caveolin 1, to the cytosol is the crucial step in the synthesis of NO. We demonstrate that the cytosolic translocation of eNOS is caused by increased synthesis of ceramide dependent by the bFGF activation of sphingomyelinase. Indeed, in the presence of the sphingomyelinase inhibitors D609 or desipramine, bFGF-dependent NO production is abrogated. To support this evidence we evaluated ceramide concentration using HPLC-electrospray ionization-mass spectrometry in controls and in bFGF-treated cells: after bFGF stimulation, a substantial increase in ceramide levels was observed. These data were further confirmed by the lack of NO production in response to fibroblast growth factor in fibroblasts derived from Niemann Pick patients who genetically lack the enzyme sphingomyelinase. In conclusion, ceramide in CHO-K1 cells is responsible for a novel Ca(2+)/calmodulin-independent mechanism for eNOS activation after fibroblast growth factor stimulation.

Animals↗