Regulation of CD59 expression on K562 cells: effects of phorbol myristate acetate, cross-linking antibody and non-lethal complement attack.

CD59 is the major membrane attack complex of complement (MAC) inhibiting protein on human cells. Its regulation is therefore an important factor in determining the fate of cells at sites of complement activation. We have chosen the K562 erythroleukaemia cell line as a model for studies of the regulation of CD59 expression, because it has previously been reported that phorbol 12-myristate 13-acetate (PMA) caused a 15-fold up-regulation of CD59 mRNA in these cells, implying a substantial capacity for CD59 synthesis. However, no assessment of CD59 protein expression was made in these studies. We show here that surface expression of CD59, as assessed by flow cytometry, was increased four-fold over a 16-hr incubation with PMA, whereas surface expression of decay-accelerating factor (DAF) (CD55) and membrane cofactor protein (MCP) (CD46) was not altered. The newly expressed CD59 was functionally active and anchored through glycosyl-phosphatidylinositol (GPI). Increased expression was dependent upon de novo protein synthesis. CD59 released into cell supernatant was also increased seven-fold by PMA, this 'secreted' CD59 retained its GPI anchor. Non-lethal complement attack did not alter CD59 expression but antibody cross-linking of CD59 caused a rapid loss of the CD59-antibody complexes. However, CD59 was quickly restored to pre-attack levels. This rapid restoration was not dependent upon protein synthesis, suggesting release from preformed stores.     

Differentiation of Achromobacter-like strains from human blood by DNA restriction endonuclease digest and ribosomal RNA gene probe patterns

Variation amongst Achromobacter-like strains was examined by DNA restriction endonuclease digestion and rDNA gene patterns generated using a non-radioactive probe. Chromosomal DNA was extracted from 12 cultures representing Achromobacter groups B, E and F, all from human blood cultures. DNA fingerprinting using EcoRI, Hae III or HindIII sub-divided the strains in a similar manner to that obtained by their protein patterns. The HaeIII patterns, with their small number of bands, were the easiest to interpret. The EcoRI patterns included a species-species triplet of bands but minor band patterns allowed further differentiation. The Achromobacter group F strains comprised a separate taxon and were distinct from the group B and E strains by all techniques examined. The study demonstrates that, in addition to total DNA digest analysis, rDNA gene restriction patterns provide a simple but discriminatory electrophoretic method for distinguishing within Achromobacter groups B and E.     

Preventive care for patients following myocardial infarction. The Wessex Research Network (WReN)

OBJECTIVE: We aimed to assess general practice care for patients following a myocardial infarction (MI). METHOD: A structured review was carried out of general practice records of patients identified from hospital administration data. A total of 266 survivors following MI were identified from the discharge data of 13 hospitals in Southern England and registered with 71 GPs belonging to the Wessex Research Network. Median time since hospital discharge was 2.1 years. The main outcome measures were the provision of appropriate preventive care, including cardiac rehabilitation, drug therapy, and lifestyle advice for modifiable risk factors. RESULTS: Basic care was provided to nearly all patients; 253 (95.1%, 95% Cl 91.8-97.4) had blood pressure documented after their MI, 216 of 234 patients eligible for aspirin (92.3%; 88.1-95.4) had been recommended treatment, and the provision of advice on smoking cessation was documented for 27 of 33 continuing smokers (81.8%; 64.5-93.0). However, only 73 of 236 patients eligible to attend a structured rehabilitation programme (30.9%; 25.0-36.8) were documented as having received rehabilitation. Of 89 patients with heart failure following MI, 33 (37.1%; 27.1-48.0) had no record of having been offered treatment with an ACE inhibitor. Total cholesterol measurement was documented for only 144 patients (54.1%; 48.1-60.1). We estimate that there is still the potential to prevent between 4 and 9 deaths in this group of 266 surviving patients in the next 2 years by further improving the quality of follow-up care. CONCLUSIONS: Preventive care in patients with proven ischaemic heart disease in general practice remains haphazard, even among doctors enthusiastic to participate in research and to audit their quality of care. As general practitioners we should ensure that we are providing high quality preventive care to patients with clinical disease before we focus on the even more demanding task of primary prevention.      

FEASIBILITY OF CONDUCTING CARDIOVASCULAR OUTCOME RESEARCH IN AUSTRALIAN GENERAL PRACTICE: RESULTS FROM THE ANBP2 PILOT STUDY

1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial.     

Factors causing interrupted delivery of enteral nutrition in trauma intensive care unit patients.

BACKGROUND: The intent of this study was to ascertain the adequacy of delivery of enteral nutrition (EN) to critically ill adult multiple trauma patients and to identify potential detrimental factors that affect EN delivery. METHODS: Retrospective observational study. Trauma intensive care unit (TICU) in a university-affiliated hospital. Adult patients (>/=18 years of age) admitted to the TICU who received enteral feeding. RESULTS: Fifty-six adult patients were enrolled for study. Patients received, on average, 67% +/- 19% of what was prescribed for 5.7 +/- 2.0 days. A total of 222 occurrences for temporary discontinuation of tube feeding were identified. Gastrointestinal intolerance, as defined by a gastric residual volume of >150 mL, abdominal pain, or >3 liquid stools per day, accounted for only 11% of the occurrences for discontinuation of feeding. Surgery (27%) and diagnostic procedures (15%) represented the majority of reasons for inadequate nutrient delivery. Minor factors for EN interruptions were mechanical feeding tube problems (8%), pharmacy delivery delay (4%), and miscellaneous factors (3%). Multiple and unknown reasons contributed to 14% and 18% of the occurrences, respectively. CONCLUSIONS: Surgery and diagnostic procedures accounted for the largest factor in enteral feeding discontinuations in our critically ill trauma patients. Gastrointestinal intolerance contributed a minor role in the temporary discontinuation of enteral feeding.     

Moyamoya disease: presentation and treatment of two cases by surgery

Stroke prophylaxis in patients with moyamoya disease has not been described previously in Australia. Two cases are presented in which superficial temporal to middle cerebral arterial bypass has been successful in halting the progress of the disease. The presentation, investigation and management of this occlusive vasculopathy are discussed.     

131I and 111In-labelled monoclonal antibody imaging of primary lung carcinoma

Preliminary clinical studies have been carried out to determine whether the monoclonal antibody 791T/36 would localize in primary lung cancer to an extent sufficient for external detection by gamma scintigraphy. Radiolabelling of the antibody with 131I permitted visualization of three out of eight (38%) tumours using planar imaging with 99Tcm-labelled blood pool subtraction. Radiolabelling of the same antibody with 111In permitted visualization of tumour uptake in nine out of 13 (69%) tumours, without the need for image subtraction. Single photon emission computed tomography (SPECT) studies of seven patients demonstrated concentration of 111In-labelled antibody at the tumour site in each case, four of which were visualized on the planar images. The present study demonstrates localization of the 791T/36 antibody in primary lung carcinoma and confirms the superiority of 111In over 131I as a radiolabel for antibody imaging, especially when emission tomography is performed. These data indicate that further work will be required to determine whether this antibody will be a suitable carrier for cytotoxic agents in the therapy of lung cancer.