Subantral recovery technique (T.R.O.A.S.).

Extensive pneumatization of the maxillary sinus can limit rehabilitation with maxillary implants. During the last 30 years, several graft addition techniques have been proposed to solve this problem. A technique without graft has been developed by the authors and the results of this technique are analyzed.

Synergy between AUUUA motif disruption and enhancer insertion results in autocrine transformation of interleukin-3-dependent hematopoietic cells.

Previously, we characterized the transposition of an intracisternal type A particle (IAP) to the 3' untranslated region (UTR) of the interleukin-3 (IL-3) gene, which displaced two of the six AUUUA motifs associated with mRNA stability in an IL-3-secreting clone. To determine whether this rearrangement was involved in the autocrine transformation of the parental IL-3-dependent FL5.12 cell line, the germline (gIL-3) and rearranged IL-3 (rIL-3) genes were isolated and subcloned into a gene transfer vector. Moreover, the IAP-long terminal repeat (LTR) and the IL-3 3' UTR AUUUA motifs were deleted (rIL-3 + delta LTR and gIL-3 + delta AUUUA) in some IL-3 constructs to ascertain their role in the transformation process. The IAP-LTR was also added to these constructs (rIL-3 + delta LTR + IAP-LTR, gIL-3 + delta AUUUA + IAP-LTR, and gIL-3 + IAP-LTR), to determine whether it was necessary for autocrine transformation. The ability of the modified IL-3 genes to abrogate the IL-3 dependency of FL5.12 cells had the following rank order: rIL-3 was greater than rIL-3 + delta LTR + IAP-LTR, which was greater than gIL-3 + delta AUUUA + IAP-LTR, which was greater than gIL-3 + delta AUUUA, which was equal to rIL-3 + delta LTR, which was greater than gIL-3. The half-life of IL-3 mRNA was 20-fold longer in cells containing a mutated as opposed to a wild-type AUUUA region. All of the factor-independent cells that expressed the IL-3 transgenes secreted IL-3 and were tumorigenic after injection into BALB/c nude mice. These results indicated that two events could synergize in the autocrine transformation of hematopoietic cells: (1) addition of a transcriptional enhancer present in a retroviral LTR, and (2) disruption of an mRNA stability region.