Use of representational difference analysis to identify Escherichia coli O157-specific DNA sequences.

Whereas several important virulence factors in Escherichia coli O157 have been identified, studies suggest they are not always essential and are probably insufficient to account for the severe clinical manifestation of E. coli O157 infection. Identification of putative virulence determinants is crucial to the understanding of bacterial pathogenesis and genomic comparison analysis may aid the characterisation of unidentified virulence attributes. In this study, representational difference analysis (RDA) was used for genomic comparison of E. coli O157 with the proposed ancestral strain, E. coli O55. Unique E. coli O157 gene sequences were isolated and one, termed RDA-1, taken forward for further analysis. Southern blotting with labelled RDA-1 as a probe showed it to be present in 77% of E. coli O157 isolates and absent in all non-E. coli O157 screened. Sequence flanking RDA-1 was obtained from a genomic clone identified by hybridisation, and contained an open reading frame predicted to encode a novel iron-regulated outer membrane protein.

The lingula is an appropriate site for lung biopsy.

BACKGROUND: Lung biopsy is commonly performed for diagnosis of diffuse pulmonary disease. The lingula offers technical advantages for biopsy, however the quality of tissue obtained by lingula biopsy has been questioned. We sought to determine whether lingula biopsy was a satisfactory site for biopsy in terms of diagnostic yield, therapeutic interventions, and survival results. METHODS: All diagnostic lung biopsies performed for diffuse lung disease at 3 university affiliated hospitals between July 1, 1992 and December 31, 1998 were retrospectively reviewed. Patients were divided into 2 groups, depending upon site of biopsy: patients with lingula biopsy only and those with biopsies from other sites. RESULTS: There were 75 patients; 20 underwent biopsy of the lingula alone, 48 had biopsy of other sites with or without biopsy of the lingula, and location of biopsy was unknown in 7 patients. Histologic diagnosis was achieved in all patients. Significant beneficial therapeutic changes were made in 14 lingula patients, and consisted of immunosuppression in 12 cases. Three patients died in the hospital or within 30 days. Fourteen patients survived 1 year. There was no significant difference between patients that had biopsy of the lingula alone and those that had biopsies from other sites in urgency, technique, histologic diagnosis, rate of therapeutic interventions, hospital mortality, or 1 year survival. CONCLUSIONS: Lung biopsy of the lingula compared to other anatomic sites has equivalent diagnostic yield, therapeutic significance, and survival. Given the technical ease of biopsy, when disease is present radiographically it is the preferred site for lung biopsy.

Rodeo related large animal injury: is protective head-gear warranted?

To compare rodeo associated large animal injuries to large animal associated trauma from other aetiologies in order to determine whether mandatory protective head-gear during rodeo is warranted. Retrospective analysis related to injury involving large animal admissions between 1 January 1990 and 31 December 1995. The setting is at the University of New Mexico Health Science Center, a level 1 trauma centre. All patients admitted with Injury Severity Scores of 1 or higher following large animal associated injuries. There were 140 admissions for which mechanism of injury was known. Thirty-nine occurred during rodeo competition and 101 occurred during other activities. Bovine associated activities were the aetiology in 34 (87%) of rodeo related injuries while equine related activities were the aetiology in 97 (96%) of non-rodeo related injuries (P<0.001). Rodeo related injuries involved the head and neck in five patients (13%) compared to 42 patients (42%) in non-rodeo activities (P=0.001). Mean Regional Injury Severity Score head and neck was 0.4 for injured rodeo riders and 1.5 for injured non-rodeo riders (P<0.001). Mean admission Glascow Coma Scale was 14.9 for rodeo-injured patients and 13.3 for non-rodeo-injured patients (P<0.001). Total ISS was significantly lower for rodeo injured patients (9.1 vs. 11.7, P=0.03). No rodeo injured patient died as a result of head injury. Mechanism of injury, ISS head, GCS, total ISS, and outcome differ between rodeo and non-rodeo injuries. While routine helmet use during non-rodeo events appears justified, mandatory use of helmets in rodeo events is unwarranted. Orthotics to protect the chest and abdomen are more likely to reduce morbidity and mortality for rodeo participants.

Lung biopsy: is it necessary?

OBJECTIVE: Lung biopsy is associated with substantial mortality rates. We reviewed our experience with this operation, primarily in patients with immunocompetence, to determine whether the results justify the continued performance of this procedure. METHODS: We conducted a retrospective review of all diagnostic lung biopsies performed at 3 university-affiliated hospitals between July 1, 1992, and December 31, 1998. RESULTS: There were 75 patients: 25 patients were treated electively, 17 were treated on an urgent basis, 27 patients on an emergency basis, and the urgency was unclear in 6 patients. Significant beneficial therapeutic changes were made in 15 of 25 elective procedures (60%), in 16 of 17 urgent procedures (94%), and in 11 of 27 emergency procedures (41%; P =.001). Significant beneficial therapeutic changes consisted of immunosuppression in 13 of 15 (87%) patients treated on an elective basis, in 9 of 16 (56%) treated on an urgent basis, and in 9 of 11 (82%) treated on an emergency basis in whom therapy was altered (P =.14). Operative death was 0 of 25 for elective operations (0%), 3 of 17 for urgent operations (18%), and 14 of 26 for emergency operations (54%). Multivariable analysis of operative death showed urgency to be the only significant predictor of death (P =.002). CONCLUSIONS: In patients with immunocompetence, elective and urgent lung biopsies have acceptable operative mortality rates and frequently result in important beneficial therapeutic changes. Consequently biopsies are appropriate in these patients. Emergency biopsies are associated with high operative mortality rates and rarely result in a therapeutic change other than immunosuppression. These patients should not undergo lung biopsy if they are in stable condition and should be treated empirically with immunosuppression without operation if their condition is deteriorating.

Families with a ventilator-assisted child: transitional issues.

This article describes families' experiences taking their ventilator-assisted children home. The intent was to learn what might better prepare families for this transition. Feedback from families after their children were home made it apparent that the transition is lengthier than had been anticipated, and that new concerns evolve. A written questionnaire and personal interview with 14 families provided insights about the characteristics of those who choose mechanical ventilation at home about their concerns both in the hospital and at home, and about the ways in which they felt best and least prepared to have their children home. The results indicated that despite an enormously stressful impact on the family, they would again make the same choice. The authors conclude with suggestions to hospital staff about collaborating earlier with community-based providers and more closely with families.

Effect of levamisole treatment on lambing performance of winter housed ewes.

The value of levamisole treatment of ewes housed during the last 10 weeks of pregnancy was studied over four successive years in a lowland flock of 400 ewes. Levamisole treatment, shortly after housing in January, improved the live lambing percentage each year, by an average of nine lambs per 100 ewes mated. Birthweight of lambs was unaffected by the improvement in lamb numbers.

The positive inotropic effect of glucagon in the chronically failed right ventricle as demonstrated in the isolated cat heart.

Previous in vitro studies had provided evidence to show that papillary muscles obtained from cats with chronic right ventricular failure had lost their ability to develop a positive inotropic response to glucagon. Since it is difficult to extrapolate from the isolated papillary muscle to the intact heart, studies were done to assess the effects of glucagon in the perfused isovolumically beating heart obtained from cats four months after surgical banding of the pulmonary artery for the experimental production of chronic right ventricular failure (CRVF). At the peak of the dose-response curve, glucagon increased right ventricular isovolumic pressure 25% (39.00 +/- 4.37 to 49.67 +/- 5.15 mm Hg; p less than 0.001) and right ventricular dP/dt 63% (522.2 +/- 93.9 to 852.6 +/- 159.9 mm Hg/sec; p less than 0.001) in 6 normal hearts. Similar dose related increases in right ventricular isovolumic pressure and dP/dt were obtained in 6 hearts taken from cats with chronic right ventricular failure. The respective increases in right ventricular isovolumic pressure and dP/dt were 43% (30.33 +/- 4.01 to 43.67 +/- 6.25 mm Hg; p less than 0.025) and 73% (317.50 +/- 30.29 to 550.83 +/- 89.04 mm Hg/sec; p less than 0.025). These results provide evidence that glucagon possesses the capacity to augment myocardial contractility in the heart with experimentally induced chronic right ventricular failure.