RESUMO
A single-base deletion within the protein-coding region of the adenovirus type 5 early region 1A (E1A) genes, 399 bases downstream from the transcription start site, depresses transcription to 2% of the wild-type rate. Complementation studies demonstrated that this was due to two effects of the mutation: first, inactivation of an E1A protein, causing a reduction by a factor of 5; second, a defect which acts in cis to depress E1A mRNA and nuclear RNA concentrations by a factor of 10. A larger deletion within the protein-coding region of E1A which overlaps the single-base deletion produces the same phenotype. In contrast, a linker insertion which results in a similar truncated E1A protein does not produce the cis-acting defect in E1A transcription. These results demonstrate that a critical cis-acting transcription control region occurs within the protein coding sequence in adenovirus type 5 E1A. The single-base deletion occurs in a sequence which shows extensive homology with a sequence from the enhancer regions of simian virus 40 and polyomavirus. This region is not required for E1A transcription during the late phase of infection.
Assuntos
Adenovírus Humanos/genética , Genes Virais , Genes , Transcrição Gênica , Proteínas Virais/genética , Sequência de Bases , Núcleo Celular/fisiologia , Transformação Celular Viral , Células HeLa/fisiologia , Humanos , Mutação , Hibridização de Ácido Nucleico , Plasmídeos , RNA Mensageiro/genética , RNA Neoplásico/genética , RNA Viral/genéticaRESUMO
We reviewed the records of 209 patients with acute diverticulitis treated from 1984 through 1989 to determine if immunocompromised patients have a worse prognosis than nonimmunocompromised patients. Forty immunocompromised patients and 169 nonimmunocompromised patients with acute diverticulitis were identified. Free perforation into the peritoneal cavity occurred in 43% (17/40) of immunocompromised patients and 14% (24/169) of nonimmunocompromised patients. Operations were performed in 58% (23/40) of immunocompromised patients and 33% (55/169) of nonimmunocompromised patients. Postoperative morbidity was 65% (15/23) in immunocompromised patients and 24% (13/55) in nonimmunocompromised patients; postoperative mortality was 39% (9/23) and 2% (1/55), respectively. We conclude that acute diverticulitis in the immunocompromised patient is a complicated problem; there is a greater risk of free perforation and need for surgery than in the nonimmunocompromised patient. Furthermore, the prognosis for immunocompromised patients who undergo surgery is worse than that for nonimmunocompromised patients.