DNA-topoisomerase I activity and content in epithelial ovarian cancer

BACKGROUND

The levels and activity of topoisomerase I were determined in 35 biopsies from patients with ovarian cancer.

PATIENTS AND METHODS

The activity was defined by the ability to relax supercoiled DNA plasmid, and levels were determined by Western blotting and immunohistochemistry.

RESULTS

We detected topoisomerase I activity in all samples, although at different levels. Enzymatic activity was the same in fresh and frozen tissues. Western blotting analysis detected topoisomerase I in 29 of 35 tumor samples but in the remaining six the levels were below the detection limit. We analyzed the distribution of topoisomerase I in tumor cells and normal infiltrating cells by immunohistochemistry. The enzyme was mainly associated with tumor cells although there were four samples in which tumor cells were negative but in which normal cells, mainly lymphocytes, yielded a positive result.

CONCLUSIONS

The results indicate that topoisomerase I enzymatic activity is detectable in human ovarian tumors, varying among patients. No correlations were found between the levels of the enzyme and its activity. Because of the high heterogeneity observed, enzymatic activity assays should be combined with immunohistochemical evaluation of Topo I in the tumor and normal cells present in the tissue.

Mandibular overdentures anchored to single implants: a five-year prospective study

STATEMENT OF PROBLEM

It is unknown what minimum number of implants are required to satisfactorily support and retain a mandibular overdenture.

PURPOSE

The purpose of this study was to evaluate a treatment modality by using mandibular overdentures anchored to single implants in a geriatric patient population.

MATERIAL AND METHODS

Twenty-one patients with a mean age of 74.2 years were treated with single implants inserted at the mandibular midline according to the standard two-stage surgical technique. O-Ring or ball attachments were connected to the implants and served as overdenture anchorage. Implant success rate, improvement of oral comfort and function, condition of the peri-implant soft tissues, Periotest values, and the interproximal marginal bone level were evaluated for up to 5 years after delivery of the overdentures.

RESULTS

None of the implants were lost during the follow-up period. A mean marginal bone loss of 1.42 +/- 0.56 mm was noted at 60 months. Plaque Index was consistently high around the abutments at all reevaluation intervals but was associated with a low Gingival Index. Pocket Depth averaged 2.41 +/- 0.17 mm for the entire follow-up period. Remarkable improvement of oral comfort and function were evidenced with the overdenture treatment.

CONCLUSION

Rehabilitation with mandibular overdentures anchored to a single implant can be a therapeutic alternative for elderly patients experiencing discomfort and functional difficulties with conventional mandibular dentures.

CD2 expression in acute promyelocytic leukemia is associated with microgranular morphology (FAB M3v) but not with any PML gene breakpoint

In the t(15;17) translocation of acute promyelocytic leukemia (APL) at least three regions of the PML gene are involved in the reciprocal translocation between the PML and the RAR-alpha loci. The chimeric PML/RAR-alpha fusion transcripts can be demonstrated in all cases of APL, by a specific reverse-transcription PCR (RT-PCR). Previous studies found a correlation between expression of CD2 and involvement of the PML bcr3. In this study, we assessed this association in 43 children and adults with APL. A blind morphologic review of all smears was performed by four experienced hemopathologists who agreed the diagnosis of M3 vs M3v APL. CD2 expression on APL was detected by using different monoclonal antibodies (MoAbs) directed against specific CD2 epitopes by flow cytometry and in selected cases by Northern blot by the use of a specific CD2 cDNA probe. Nineteen of 43 cases displayed the typical microgranular features consistent with the diagnosis of M3v. Of these, 12 had the bcr3 breakpoint on chromosome 15, while seven had the bcr1 type. In 16 of the 19 patients, leukemic cells expressed both CD2 protein and the corresponding mRNA. Similarly, in the negative cases, Northern blot analysis failed to demonstrate the presence of specific mRNA. The remaining 24 patients, with the classic morphologic features of M3, were CD3 negative. These results point out that CD2 expression correlates with the FAB M3v and not with the PML breakpoints. During the course of all-trans retinoic treatment a down-modulation of CD2 expression was observed in three M3v cases. Overall, our findings might suggest a role of CD2 epitopes in the regulation of adhesion properties of APL blast cells.

Single-tooth implant rehabilitation: a retrospective study of 67 implants

The use of osseointegrated implants is an accepted procedure for the treatment of total and partial edentulism and offers good predictability of long-term success. For the last several years, this procedure has also been used for single-tooth replacement following loss of teeth for traumatic, periodontal, and carious lesions. This paper reports the clinical experience of 47 patients treated for a single-tooth replacement. Sixty-seven screw-type standard, self-tapping implants and mini-implants were placed. The results were similar to those for complete and partial osseointegrated prostheses. The total implant survival rate was 94.4%. Two implants were lost as a result of suppuration caused by membrane exposure, while another was lost after loading. The results suggest that single-tooth replacement using osseointegrated implants provides predictable success.

Reciprocal translocation t(12;13)(p13;q14) in acute nonlymphoblastic leukemia: report and cytogenetic analysis of two cases

Two cases of acute nonlymphoblastic leukemia with a reciprocal translocation t(12;13)(p13;q14) are described. Both patients were male adults with a diagnosis of M0 FAB type. Beside standard cytogenetic analysis, we applied fluorescence in situ hybridization (FISH) in order to investigate the position of the RB gene with respect to the breakpoint at 13q14. Our results showed that the RB gene was proximal to the breakpoint, but, apparently, not split in either case.