Retrospective evaluation of gynecologic cytodiagnosis. II. Interlaboratory reproducibility as shown in rescreening large consecutive samples of reported cases

Two laboratories exchanged and rescreened a large sample of cases with cervicovaginal smears they had consecutively accessioned to examine the reproducibility of gynecologic cytodiagnosis under optimum conditions. At least a "working agreement" (diagnoses within +/- 1 category on a ten-category scale) was achieved in diagnoses of normal, benign reaction and squamous abnormality (from minimal dysplasia though invasive cancer) in 18,859 cases (96.8%), of endometrial abnormality in 21 cases (42%) and of "unsatisfactory" in 99 cases (20.7%). Larger differences occurred in greater than or equal to 30% of cases except in the categories of "normal" and "benign reaction," reaching a maximum of 82% for moderate dysplasia. Reexamining 382 cases decreased disagreement by category to the 20% to 65% range only in the five categories of dysplasia plus carcinoma in situ. Agreement was not predicated on the presence of endocervical cells or squamous metaplasia; the basis for "unsatisfactory" calls was not uniform. Comparison of the laboratories' diagnoses with referee diagnoses or, on 178 cases, with tissue diagnoses also demonstrated differences in diagnostic criteria.     

Novel silylated steroids as aromatase inhibitors

Androst-4-en-3-one analogs incorporating a trimethylsilyl or a trimethylsilylmethyl group at C-1, C-2 or C-19 were prepared and evaluated as inhibitors of aromatase. Only 10-[1-hydroxy-2-(trimethylsilyl)ethyl]estr-4-ene-3,17-dione inhibited human placental aromatase. Enzyme kinetic analysis revealed competitive inhibition [apparent dissociation constant (Ki) of 562 +/- 12 nM] associated with marginal time-dependent inhibition.     

An essential E box in the promoter of the gene encoding the mRNA cap-binding protein (eukaryotic initiation factor 4E) is a target for activation by c-myc.

The mRNA cap-binding protein (eukaryotic initiation factor 4E [eIF4E]) binds the m7 GpppN cap on mRNA, thereby initiating translation. eIF4E is essential and rate limiting for protein synthesis. Overexpression of eIF4E transforms cells, and mutations in eIF4E arrest cells in G, in cdc33 mutants. In this work, we identified the promoter region of the gene encoding eIF4E, because we previously identified eIF4E as a potential myc-regulated gene. In support of our previous data, a minimal, functional, 403-nucleotide promoter region of eIF4E was found to contain CACGTG E box repeats, and this core eIF4E promoter was myc responsive in cotransfections with c-myc. A direct role for myc in activating the eIF4E promoter was demonstrated by cotransfections with two dominant negative mutants of c-myc (MycdeltaTAD and MycdeltaBR) which equally suppressed promoter function. Furthermore, electrophoretic mobility shift assays demonstrated quantitative binding to the E box motifs that correlated with myc levels in the electrophoretic mobility shift assay extracts; supershift assays demonstrated max and USF binding to the same motif. cis mutations in the core or flank of the eIF4E E box simultaneously altered myc-max and USF binding and inactivated the promoter. Indeed, mutations of this E box inactivated the promoter in all cells tested, suggesting it is essential for expression of eIF4E. Furthermore, the GGCCACGTG(A/T)C(C/G) sequence is shared with other in vivo targets for c-myc, but unlike other targets, it is located in the immediate promoter region. Its critical function in the eIF4E promoter coupled with the known functional significance of eIF4E in growth regulation makes it a particularly interesting target for c-myc regulation.