[DNA ploidy determination with flow cytometry, Ki-67 index and overexpression of p53 protein in 121 T1 superficial bladder carcinomas. Retrospective studies. Part II: Prognostic value and usefulness in the indication for prophylactic treatment with BCG]. / Determinación de ploidía de ADN mediante citometría de flujo, indice Ki-67 y sobre-expresión de proteína p53 en 121 carcinomas superficiales de vejiga T1. Estudio retrospectivo. 2a Parte: Valor pronóstico y utilidad en la indicación de tratamiento profiláctico con BCG.

OBJECTIVE: Evaluate the utility of Ki-67 label index, p53 expression and flow cytometry-DNA ploidy in the selection of groups to be treated with prophylactic BCG and the prognostic value compared with the classic variables (grade, lymphatic permeation, multiplicity, volume, primary). MATERIAL & METHOD: 121 superficial bladder tumors T1. 10% Cut-off level for Ki-67 and p53. Aneuplody is defined as a tumor with DNA index different of 1 or more than 20% in G2-M phase. 71 (58.7%) received BCG. RESULTS: In uni and multivariate analysis positivity to Ki-67 is correlated with recurrence. Progression is correlated with lymphatic permeation (p .0003), volume (p .016), ploidy (p .022) and positivity to p53 (p .007). In multivariate analysis, volume and positivity to p53 are independent variables. None were of utility to prevent recurrence, but Ki-67 positive or aneuploid treated tumors had less progression (p .025 and p .009 respectively). The p53 negative treated tumors had less progression too. CONCLUSIONS: Only Ki-67 is correlated with tumoral recurrence. P53 and tumor volume are correlated with stage progression. If the results are confirmed with bigger series, the Ki-67 positive and/or aneuploid tumors would obtain benefits of prophylactic treatment with BCG.

[Randomized prospective study comparing BCG and BCG plus oral tegafur in the prevention of stage T1 superficial tumors of the bladder. Results after 2.5 years]. / Estudio aleatorio prospectivo comparando BCG y BCG más Tegafur oral en la profilaxis de los tumores superficiales de vejiga estadio T1. Resultados a dos años y medio.

We present our experience in eighty patients with superficial bladder cancer stage T1. They have been randomized to receive BCG 27 mg weekly x 6 and monthly until complete one year (Group A) or the same schedule plus Tegafur 800 mg daily until complete one year. Results are similar in both groups. With a median follow up of two years and a half, 33% in Group A and 20% in Group B have had recurrence; 7.6% in group A and 3% in group B have had progression in stage. Differences are not significant in both cases. Tolerance of Tegafur is good with only 11% of secondary effects. We concluded that there are no differences in both treatments but there is a trend to better results with combinant therapy. It is necessary more patients to achieve definitive results.

[The BTA test in the diagnosis of bladder tumors. Usefulness in the hospital setting]. / Test de bta en el diagnóstico de los tumores vesicales. Utilidad en un medio hospitalario.

We show our results in the diagnostic and follow-up of the bladder tumors comparing de BTA test with Void Cytology, in order to substitute this with the former. We performed BTA test, Void Cytology (of the same sample) and abdominal ultrasound to 133 patients. They are divided in three groups: 45 with bladder tumor, 16 healthy controls, 72 in follow-up with and without prophylaxis. The sensibility and specificity in tumor's group were similar. In controls' and follow-up's groups the void cytology specificity was superior. There is a high number of false positives in the follow-up group with a large number of "white" cystoscopes. A high number of false positives was seen if the BTA test was done in he first three months of follow-up. In the subgroup in prophylaxis with cystostatic there weren't false positives. We conclude that BTA test is useful in the diagnostic of bladder tumor but not in the follow-up, especially in the first three months.

Arresting tissue invasion of a parasite by protease inhibitors chosen with the aid of computer modeling.

Computer modeling of the three-dimensional structure of an enzyme, based upon its primary sequence alone, is a potentially powerful tool to elucidate the function of enzymes as well as design specific inhibitors. The cercarial (larval) protease from the blood fluke Schistosoma mansoni is a serine protease hypothesized to assist the schistosome parasite in invading the human circulatory system via the skin. A three-dimensional model of the protease was built, taking advantage of the similarity of the sequence of the cercarial enzyme to the trypsin-like class of serine proteases. A large hydrophobic S-1 binding pocket, suspected from previous kinetic studies, was located in the model and confirmed by new kinetic studies with both synthetic peptide substrates and inhibitors. Unexpected structural characteristics of the enzyme were also predicted by the model, including a large S-4 binding pocket, again confirmed by assays with synthetic peptides. The model was then used to design a peptide inhibitor with 4-fold increased solubility, and a series of synthetic inhibitors were tested against live cercariae invading human skin to confirm that predictions of the model were also applicable in a biologic assay.

Organization of multiple regulatory elements in the control region of the adenovirus type 2-specific VARNA1 gene: fine mapping with linker-scanning mutants.

The adenovirus type 2-specific virus-associated RNA 1 (VARNA1) gene is transcribed by eucaryotic RNA polymerase III. Previous studies using deletion mutants for transcription have shown that the VARNA1 gene has a large control region which is composed of several regulatory elements. Twenty-five exact linker-scanning mutations in the control region, from -33 to +77, of this gene were used for definition of the number and boundaries of these elements. The effects of these mutations on transcription and competition for transcription factors in human KB cell extracts revealed five positive regulatory elements. The essential element, which coincided with the B block, was absolutely required for both transcription and formation of stable complexes. A second element, which included the A block, was also required for both transcription and formation of stable complexes. Although this element is not as essential as the B-block element, together with the B-block element it may be necessary for formation of the most basal form of transcription machinery. Therefore, these two elements are the promoter elements in this gene. In addition, one possible element in the interblock region and two elements in the 5' flanking region were also required for efficient transcription, but they were moderately required for formation of stable complexes. Transcription of these mutants and the wild-type gene using an extract of 293 cells was stimulated at least threefold over that with the KB cell extract, as expected. Similar regulatory elements of this gene were revealed, however, when the 293 cell extract was used for transcription of these mutants, suggesting that the E1A-mediated specific transcription factors act on the transcription machinery in a sequence-nonspecific manner.

Defining the functional domains in the control region of the adenovirus type 2 specific VARNA1 gene.

The outer boundaries of the internal transcriptional control region in the VARNA1 gene have been located from positions +10 to +69. To further define the detailed organization of the functional domains in this region and the function(s) of the 5' flanking sequence, and to obtain a more detailed insight into other transcriptionally important sequences, we have constructed 77 mutants with deletion endpoints at almost every one to five base-pairs in the entire region from -30 to +160 for transcriptional studies. Using our highly active crude extract under our assay conditions, and quantitatively measuring the transcriptional efficiency and competing strength of each mutant, we have revealed new features of important transcriptional control sequences and defined the transcriptional functions of several functional domains in this gene. The essential domain is from +59/+63 to +66/+68, which corresponds to the B block sequence. This is smaller than that defined previously. The second most important domain is the region from +12/14 to +40, which includes the A block sequence that dictates the wild-type major start site and amplifies the events started by the B block region, mediated through factors and RNA polymerase III. Furthermore, the domain from -5 to +11 affects the use of certain start site(s). Moreover, the 5' flanking region from -30 to +1 contributes 80 to 90% of the overall transcriptional efficiency of the gene. Finally, our transcriptional studies of mutants deleted of the A block sequence and all of the upstream sequence indicated that an intimate interaction between the two blocks is essential for initiation of transcription. Furthermore, the B block sequence is more important than the A block sequence in the transcription reaction. The mechanism and control of transcriptional initiation in the VARNA1 gene is similar to that in some tRNA genes, but differs from that in others.

Functions of and interactions between the A and B blocks in adenovirus type 2-specific VARNA1 gene.

The internal transcriptional control region (ITCR) of VARNA1 gene consists of a 33-base-pair (bp) interblock sequence and two 12-bp sequence blocks that are highly conserved in most of the genes transcribed by RNA polymerase III. To define the functions of and study the interactions between the two blocks, we have constructed mutants with altered interblock sequence or spacing for transcription. The results of transcription efficiencies and competing strengths indicated that the interblock sequence was dispensable and the A and B blocks were essential for transcription control. One of the major functions of the interblock sequence was to maintain an optimal spacing for an intimate interaction between the two essential blocks. Shortening or elongating the interblock spacing in the mutants beyond this range drastically decreased the transcription efficiencies and competing strengths of these mutated genes. To further study how the interaction between the two blocks leads to initiation, the start sites and sizes of RNA products of the mutants were determined. When the interblock spacing was less than 105 bp, the wild-type start site was dictated by the A block after an interaction with the B block through proteins. However, when the interblock spacing was longer than 105 bp, several new start sites located closer to the B block were preferentially used. This suggests that new start sites may be dictated by the B block when its interaction with the A block is weakened by longer spacing. The mechanisms of interaction between the bipartite domain in this gene leading to initiation are different from those in tRNAs and Alu-family RNA genes.