Genetics: Changing Health Care in the 21st Century

Advances in human genetics are rapidly changing the scope of information and care that can be provided to health care consumers. By the year 2005 it is expected that the entire human genome will be mapped and all 70,000–100,000 genes will be identified. Currently, there are more than 5,000 known single-gene disorders. With the movement of specialized health services into the primary care setting, nurses increasingly will need to be knowledgeable about genetic disorders, screening/diagnostic tests, and implications for health care. In addition, the management of genetic information raises issues of informed consent, privacy and confidentiality, truth telling and disclosure, and nondiscrimination.     

Genetic analysis of the yeast NUD1 endo-exonuclease: a role in the repair of DNA double-strand breaks

The deoxyribonucleases (DNases) have been shown genetically to be important in the vital processes of DNA repair and recombination. The NUD1 gene, which codes for an endo-exonuclease of Saccharomyces cerevisiae, was analyzed for its role in the DNA double-strand break (DSB) repair processes. While the nud1 strain is only slightly sensitive to ionizing radiation, expression of the HO-endonuclease to introduce a DSB at the MAT locus in that strain results in cell death. Cell survival is inversely proportional to the duration of HO-endonuclease expression. Analysis of the surviving colonies from the nud1 strain indicated that many of the survivors are sterile and that the proportion of these sterile survivors increases with the time of HO-endonuclease expression. On the other hand, the surviving colonies from the isogenic NUD1 strain are mating-proficient. Interestingly, double mutants of nud1 rad52 are more resistant to ionizing irradiation than the rad52 strain and have a cell-survival fraction of 32% for rad52-1 nud1 and 9% for rad52::URA3 nud1 following prolonged HO-endonuclease expression, indicating that nud1 has a suppressor effect on the DSB-induced lethality in rad52. Polymerase chain reaction analysis showed that many of the nud1 survivors contained small alterations within the MAT locus, suggesting that the survivors arose through the process of non-homologous end-joining. These results suggest that the endo-exonuclease acts at a DSB to promote DNA repair via the homologous recombination pathway. Received: 20 July / 20 September 1998     

Interaction between ciprofloxacin and vancomycin against staphylococci

The interaction between ciprofloxacin and vancomycin against nine isolates of Staphylococcus epidermidis from cases of infective endocarditis and three strains of S. aureus was studied. Killing curves indicated the presence of antagonism in the early stages, the clinical significance of which is uncertain. No synergy was found and the combination therefore does not appear to offer any advantages over vancomycin alone for the treatment of staphylococcal infections.     

An audit of general practitioner referrals for pelvic ultrasound

Pelvic ultrasound is a widely used diagnostic tool and accessto this investigation is not universally available to all generalpractitioners (GPs). The aim of this study was to assess ifGPs working in the United Arab Emirates (UAE) were using pelvicultrasound appropriately by determining the rates of diagnosticyield and referral after the investigation. It was then ascertainedif these results were affected by the post-graduate trainingor gender of the doctor. The subjects were adult females whohad had a pelvic ultrasound ordered by a GP over a 2-month period.A chart review determined the presenting complaint, the completenessof the request form, the result of the ultrasound and subsequentmanagement of the patient. Diagnostic yields and referral rateswere similar to those found in other studies and were unaffectedby the post graduate training or gender of the doctor or theamount of information contained in the request form. This studysupports the premise that GPs can use pelvic ultrasound appropriatelyand should be allowed free access to this investigation.     

Intra-specific variation withinEimeria tenella detected by the random amplification of polymorphic DNA

The random amplification of polymorphic DNA (RAPD method), was used to derive fragments of DNA of the coccidial parasiteEimeria tenella for use both as genetic markers and as an aid for the discrimination of different wild-type and attenuated populations. Of 41 arbitrarily chosen 9-to 27-mer primers, 24 yielded useful arrays of fragments following low-stringency annealing conditions and the resultant profiles were generally very reproducible. One non-variant fragment of 2 kb hybridised to a single chromosome (number 12) and four variant fragments were identified. These results strongly suggest that the RAPD method may be an extremely useful tool for studies on various aspects of the genetic organisation of coccidial parasites.