Biomedical subjects
S E Rushing
Publications and source records attributed to S E Rushing.
Completely submerged primary molars.
Two mixed dentition cases have been presented which became quite complicated because of ankylosed and submerged primary second molars. These cases demonstrate the need for an early orthodontic evaluation and interceptive orthodontics. The orthodontic and surgical procedures required for these two patients could have easily been avoided by removing the ankylosed primary molars and placing space maintainers. (Of course this depends upon the parents responding to their dental recall notices.) If a submerging primary molar is retained too long, the second premolar may become displaced superiorly and the permanent first molar may migrate mesially as it erupts. Both of these problems can be prevented by extracting the ankylosed primary second molar before it submerges below the mesial height of contour of the permanent first molar. A fixed space maintainer then becomes necessary to prevent loss of arch length by mesial migration of the permanent molar.
Antibodies to CD40 prevent Epstein-Barr virus-mediated human B-cell lymphomagenesis in severe combined immune deficient mice given human peripheral blood lymphocytes.
CD40 is expressed on both normal and neoplastic B lymphocytes. Signal transduction through CD40 in vitro has been shown to exert stimulatory effects on normal B cells and inhibitory effects on Epstein-Barr virus (EBV)-induced B-cell lymphoma lines and some other cell lines derived from patients with aggressive histology lymphoma. The transfer of normal human peripheral blood lymphocytes (huPBL) from EBV-seropositive donors into severe combined immune deficient (SCID) mice has been previously shown to result in the generation of human B-cell lymphomas. These tumors are similar to the highly aggressive EBV-induced lymphomas that can arise clinically after transplantation or in the setting of immunodeficiency. Treatment of huPBL-SCID chimeric mice with anti-CD40 or anti-CD20 monoclonal antibodies (MoAb) significantly delayed the development of EBV-induced B-cell lymphoma. However, the effects of the two MoAb were mechanistically distinct. Anti-CD40 treatment prevented lymphoma generation, while still allowing for functional human B-cell engraftment in the huPBL-SCID mice compared with mice receiving no treatment, all of which succumbed to lymphoma. By contrast, treatment with anti-CD20 significantly inhibited total human B-cell engraftment in the SCID recipients, which accounted for the absence of lymphomas. In vitro assays examining the transformation of human B cells by EBV also indicated that anti-CD40 could directly inhibit EBV-transformation, whereas anti-CD20 antibodies had no effect. Thus, anti-CD40 exerts selective effects to allow for the engraftment of normal human B cells and prevent the emergence of EBV lymphomas. Stimulation of CD40 by antibodies or its physiologic ligand may, therefore, be of significant clinical use in the prevention of EBV-induced B lymphomas that may arise when EBV-seropositive individuals receive immunosuppressive regimens after transplantation or in immune deficiency states, such as acquired immune deficiency syndrome.
How dentists perceive the effects of orthodontic extraction on facial appearance.
In recent years, orthodontic treatment, particularly that involving premolar extractions, has been alleged to cause flat facial profiles. Those who make such assertions also claim to be able to instantly identify from a distance faces of patients who have received orthodontic treatment. These are strong claims that could profoundly affect the public's perception of dentistry and its specialties. This study examined whether dentists could distinguish between profiles of treated and untreated patients as well as between patients who had undergone extraction and those who had not.