Activation of the gene encoding decay accelerating factor following nerve growth factor treatment of sensory neurons is mediated by promoter sequences within 206 bases of the transcriptional start site

This study was designed to develop a quick methodology to assess the healthcare needs of a rural community and to determine what factors make these communities 'happy' or 'unhappy' with respect to medical service provision. Two rural shires of approximately 4000 people each were chosen from different health regions of Western Australia. The methodology consisted of interviews with healthcare providers and key community informants as well as a community questionnaire. The interviewing process showed that key community informants offered no new information in addition to that already provided by the healthcare providers. Furthermore, all key points would have been covered by interviewing approximately 60% of all healthcare providers in each community. Hand delivery of the community questionnaire yielded the highest response rate. The level of community satisfaction with general practitioner (GP) and hospital services determines whether a community is medically 'happy' or 'unhappy'.     

Accuracy of replication in the polymerase chain reaction. Comparison between Thermotoga maritima DNA polymerase and Thermus aquaticus DNA polymerase

A lung suppuration may result in a lung bulla with its own course. We report such a case following a Pseudomonas aeruginosa pneumonia of the upper right lobe, after aspiration of gastric contents, in a 21-year-old tracheotomized patient in chronic post-traumatic coma. Mechanical ventilation (IPPV) was indicated because of respiratory insufficiency. The pneumonia was followed by an abscess and later a lung bulla, increasing in size under the effect of mechanical ventilation with progressive mediastinal compression. Surgery was contraindicated because of poor physical status. An acute episode of cardiac tamponade was controlled with an emergency transthoracic drain insertion into the bulla. The course was favourable after a drainage for 23 days and a persisting small cavity in the lung apex. All weaning attempts being unsuccessful, the patient was discharged under home mechanical ventilation. A CT-scan control 6 months later showed a normal lung parenchyma. The various alternative techniques to surgery for treatment of a lung bulla are discussed.     

DNA polymerase epsilon: aphidicolin inhibition and the relationship between polymerase and exonuclease activity

Calf thymus DNA polymerase epsilon readily uses short, synthetic oligonucleotides as substrates for both polymerase and exonuclease activity. These substrates were used to examine the mechanism of inhibition by aphidicolin. Aphidicolin competes with each of the four dNTPs for binding to a pol epsilon.DNA complex. Importantly, aphidicolin binds equally well regardless of the identity of the next template base to be replicated (Ki approximately 0.6 microM). Hydrolysis of synthetic templates of defined sequence by the 3'-->5' exonuclease was examined. pol epsilon preferred to hydrolyze single-stranded DNA 3-fold better than double-stranded DNA (Vmax/KM), while under Vmax conditions single-stranded DNA was hydrolyzed 100-fold faster than double-stranded DNA. Aphidicolin did not inhibit exonuclease activity on single-stranded DNA; however, activity on double-stranded DNA was partially inhibited. Formation of an E.[template.primer].aphidicolin ternary complex inhibits exonuclease activity. However, even under conditions where the polymerase site is completely blocked by a template-primer, the exonuclease retains significant activity.     

The 40-kDa subunit of DNA fragmentation factor induces DNA fragmentation and chromatin condensation during apoptosis

We report here the reconstitution of a pathway that leads to the apoptotic changes in nuclei by using recombinant DNA fragmentation factor (DFF), a heterodimeric protein of 40 and 45 kDa. Coexpression of DFF40 and DFF45 is required to generate recombinant DFF, which becomes activated when DFF45 is cleaved by caspase-3. The cleaved fragments of DFF45 dissociate from the DFF40, the active component of DFF. Purified DFF40 exhibited an intrinsic DNase activity that was markedly stimulated by chromatin-associated proteins histone H1 and high mobility group proteins. DFF40 also triggered chromatin condensation when incubated with nuclei. These data suggest that DFF40 is sufficient to trigger both DNA fragmentation and chromatin condensation during apoptosis.     

Temperature-sensitive DNA polymerase induced by a bacteriophage T5 mutant: relationship between polymerase and exonuclease activities

DNA polymerase induced by bacteriophage T5ts53, a mutant with temperature-sensitive polymerase, was purified to about 95% purity as judged by dodecyl sulfate gel electrophoresis. The 3' leads to 5' exonuclease associated with the polymerase had higher activity than that associated with the parent wild-type enzyme. It was more stable to heat than the polymerase, and it degraded primer-template even in the presence of 4 dNTP's at higher temperature. However, the evidence presented shows that the inhibition of DNA synthesis by higher temperature was primarily due to defects in polymerase function rather than to overactive exonuclease. The presence of primer-template DNA stabilized the polymerase to heat. Purified ts53 polymerase was also shown to discriminate against incorportion of BrdUMP, especially at higher temperature. This is an agreement with observations made in vivo with ts53-infected bacteria.