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Biomedical subjects

D A Campbell

Publications and source records attributed to D A Campbell.

At least 19 recordsLinked to original sources
PubMed2006

Surgery for non-small cell lung cancer: systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Surgery is considered the treatment of choice for patients with resectable stage I and II (and some patients with stage IIIA) non-small cell lung cancer (NSCLC), but there have been no previously published systematic reviews. METHODS: A systematic review and meta-analysis of randomised controlled trials was conducted to determine whether surgical resection improves disease specific mortality in patients with stages I-IIIA NSCLC compared with non-surgical treatment, and to compare the efficacy of different surgical approaches. RESULTS: Eleven trials were included. No studies had untreated control groups. In a pooled analysis of three trials, 4 year survival was superior in patients undergoing resection with stage I-IIIA NSCLC who had complete mediastinal lymph node dissection compared with lymph node sampling (hazard ratio estimated at 0.78 (95% CI 0.65 to 0.93)). Another trial reported an increased rate of local recurrence in patients with stage I NSCLC treated with limited resection compared with lobectomy. One small study reported a survival advantage among patients with stage IIIA NSCLC treated with chemotherapy followed by surgery compared with chemotherapy followed by radiotherapy. No other trials reported significant improvements in survival after surgery compared with non-surgical treatment. CONCLUSION: It is difficult to draw conclusions about the efficacy of surgery for locoregional NSCLC because of the small number of participants studied and methodological weaknesses of the trials. However, current evidence suggests that complete mediastinal lymph node dissection is associated with improved survival compared with node sampling in patients with stage I-IIIA NSCLC undergoing resection.

Carcinoma, Non-Small-Cell Lung↗
PubMed2006

Retrospective data for diabetic foot complications: only the tip of the iceberg?

Admission rates for diabetes-related foot complications to an Australian hospital were assessed by comparing the frequently used method of retrospectively identifying patients according to International Classification of Diseases (ICD) codes with that of prospectively identifying patients at the time of admission. The aim was to determine the true admission rate of diabetes-related foot complications and to assess the ability of ICD discharge codes to accurately represent the clinical severity of each identified admission. The retrospective study of ICD codes identified approximately one-third of the patients admitted during the prospective studies. Furthermore, ICD codes allocated in the prospective studies failed to accurately represent the clinical condition in 61% of cases and the corresponding Weighted Inlier Equivalent Separations weighting resulted in a $215,000/year deficit for admissions to a single hospital.

Adult↗
PubMed2006

A call for a national transplant surgical quality improvement program.

The severity of illness in transplant patients and the complexity of transplant operations results in significant postoperative morbidity and mortality. Remarkable efforts have been made by transplant physicians to study and improve organ allocation, graft and patient survival, immunosuppression and the long-term management of post-transplant complications. Less effort has been spent studying the actual transplant operation and systems of acute transplant care. The National Surgical Quality Improvement Program (NSQIP) has provided a standardized approach to quality improvement and has demonstrated significant potential for a reduction in postoperative morbidity and mortality in other surgical disciplines. Medical centers are under increasing pressure to measure surgical quality and the nexus of transplant surgical quality improvement should not lie in the hands of CMS or JACHO, but rather it should be created and developed within the transplant community. The time has come for a national transplant surgical quality improvement program based on the NSQIP infrastructure. Such a proactive approach toward quality improvement from the transplant community is an excellent investment for patients, providers and health care payers.

Humans↗
PubMed2005

Surgery for early stage non-small cell lung cancer.

BACKGROUND: Surgical resection (usually lobectomy) is considered the treatment of choice for individuals with stage I and II non-small cell lung cancer (NSCLC) and for some patients with resectable stage IIIA NSCLC. However much of the evidence supporting surgery is observational. OBJECTIVES: To determine whether, in patients with early stage non-small cell lung cancer, surgical resection of cancer improves disease-specific and all-cause mortality compared with no treatment, radiotherapy or chemotherapy. To compare the effectiveness of different surgical approaches (e.g. lobectomy versus limited resection) in improving disease-specific or all-cause mortality in patients with early stage lung cancer. SEARCH STRATEGY: Electronic databases (the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE (1966 to December 2003)), bibliographies, handsearching of a journal and discussion with experts were used to identify published and unpublished trials. SELECTION CRITERIA: Randomised controlled trials comparing surgery alone (or in combination with other therapy) with non-surgical therapy and randomised trials comparing different surgical approaches. DATA COLLECTION AND ANALYSIS: A pooled hazard ratio was calculated where possible. Tests for statistical heterogeneity were performed. MAIN RESULTS: Eleven trials were included with a total of 1910 subjects. There were no studies with an untreated control group. In a pooled analysis of three trials, four-year survival was superior in patients with resectable stage I to IIIA NSCLC who underwent resection and complete mediastinal lymph node dissection compared with those undergoing resection and lymph node sampling, the hazard ratio was estimated to be 0.78 (95% CI 0.65-0.93, P = 0.005). A further trial found an increased rate of local recurrence in patients with stage I NSCLC treated with limited resection compared with lobectomy. One small trial found a survival advantage in favour of chemotherapy followed by surgery compared to chemotherapy followed by radiotherapy in patients with stage IIIA NSCLC. However none of the other trials included in the review demonstrated a significant improvement in survival in patients treated with surgery compared with non surgical therapy. Several of the included trials had potential methodological weaknesses. AUTHORS' CONCLUSIONS: Conclusions about the efficacy of surgery for local and loco-regional NSCLC are limited by the small number of participants studied to date and potential methodological weaknesses of trials. Current evidence suggests that lung cancer resection combined with complete mediastinal lymph node dissection is associated with a small to modest improvement in survival compared with lung cancer resection combined with systematic sampling of mediastinal nodes in patients with stage I to IIIA NSCLC.

Carcinoma, Non-Small-Cell Lung↗
PubMed2005

Creation of a multidisciplinary, evidence based, clinical guideline for the assessment, investigation and management of acute diabetes related foot complications.

AIMS: To design a multidisciplinary, evidenced-based, clinical guideline for the assessment, investigation and management of inpatients with acute diabetes related foot complications. METHODS: A systematic search of both published (identified by searching all major electronic databases and hand searching key journals) and unpublished literature (derived from national and internationally recognized experts) identified 266 articles specific to diabetes related foot complications. Of these, 126 (47%) were assessed to be methodologically sound and clinically relevant. A narrative summary with the articles tabulated according to their level of evidence was prepared. A multidisciplinary expert group of health professionals, with a known interest and recognized expertise in diabetes related foot complications, was established to assess the evidence. RESULTS: The multidisciplinary expert group used the identified literature and clinical experience to create a comprehensive, evidence-based, clinical guideline for the assessment, investigation and management of acute diabetes related foot complications. Included within the guideline is a novel, diabetes specific classification system, which codes for the presence/absence and severity of the four principle causative factors (Neuropathy, Vascular compromise, Ulceration and Infection) in the development of acute diabetes related foot complications. CONCLUSION: Through the creation and implementation of this evidence-based clinical guideline, specific for acute diabetes related foot complications, it is hoped that health professionals will be better equipped to make informed decisions for this patient population. This may benefit the individual and health system through reductions in amputation rate, length of hospital stay and health expenditure.

Decision Making↗
PubMed2004

Trypanosomatid biodiversity in Costa Rica: genotyping of parasites from Heteroptera using the spliced leader RNA gene.

The biodiversity of insect trypanosomes is largely unknown, resulting in significant gaps in the understanding of pathogen evolution. A culture-independent preliminary survey of trypanosomatid fauna was conducted for the parasites of Heteroptera (Hemiptera) from several localities in Costa Rica. Trypanosomatid infections were detected by light microscopy of smeared gut contents. Out of 257 insects representing 6 families, infections were found in 62 cases; cultures were obtained for 29 new isolates. Gut material from infected hosts was preserved in the field using an SDS-EDTA buffer solution for subsequent DNA extraction in the laboratory. PCR amplification of the trypanosomatid-specific spliced leader (SL) RNA gene repeats was successful for 60 field samples. Eighteen distinct SL RNA typing units were identified in a set of 28 samples analysed in detail. Cluster analysis indicated that these typing units were unique and thus could represent new species and, in some cases, new genera. This study reveals only a minor fraction of the trypanosomatid biodiversity, which is anticipated to be high.

Animals↗
PubMed2004

A Gilbert's syndrome UGT1A1 variant confers susceptibility to tranilast-induced hyperbilirubinemia.

Tranilast (N-(3'4'-demethoxycinnamoyl)-anthranilic acid (N-5)) is an investigational drug for the prevention of restenosis following percutaneous transluminal coronary revascularization. An increase in bilirubin levels was observed in 12% of patients upon administration of tranilast in a phase III clinical trial. To identify the potential genetic factors that may account for the drug-induced hyperbilirubinemia, we examined polymorphisms in the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene in over a thousand patients. Our results suggested that the TA repeat polymorphism in UGT1A1, which predisposes some individuals to Gilbert's syndrome, predicted the susceptibility to tranilast-induced hyperbilirubinemia. The (TA)(7)/(TA)(7) genotype was present in 39% of the 127 hyperbilirubinemic patients vs 7% of the 909 controls (P=2 x 10(-22)). Rapid identification of genetic factors accounting for the observed adverse effect during the course of a double-blind clinical trial demonstrated the potential application of pharmacogenetics in the clinical development of safe and effective medicines.

Dinucleotide Repeats↗
PubMed2004

Assessment and management of inpatients with acute diabetes-related foot complications: room for improvement.

BACKGROUND: Australian data are currently lacking regarding management guidance, resource usage and outcomes of patients with diabetes requiring hospitalization for management of acute foot complications. AIMS: The aims of the present study were to review hospital admissions for diabetes-related foot complications and current assessment and management of these complications, and to formulate recommendations for future models of care. METHODS: A retrospective review of patient records from 1 July 1999 to 30 June 2000 was carried out. Recorded assessment, investigations, management, amputation rates, referral rates and length of hospital stay were reviewed. RESULTS: There were 69 admission episodes in 12 months (total patients n = 50). The mean age was 64 years, with 44 male patients (64%) and 25 female patients (36%). The mean diabetes duration was 11 years (range <1-47 years). The majority of patients had type 2 diabetes. Assessment for known risk factors for ulceration and amputation was variable with history of previous ulcer/amputation recorded for 24 (35%) admissions, results of neurological assessment recorded for 11 (16%) and assessment of pedal pulses documented for 51 (74%). Glycated haemoglobin was performed during 35 (51%) admissions. Patients were admitted under one of 11 different inpatient units and the average interdepartmental referral rate was one referral per patient per admission. The average length of stay was 17 days, with total bed days occupied 1163 days. Minor amputation was performed in 25 (36%) cases and major amputation in 8 (11%). CONCLUSIONS: Clinical assessment, investigation and management of this population are highly variable. This has a significant impact on the final clinical outcome, and changes to current processes are required to overcome the substantial burden of diabetic foot disease.

Amputation, Surgical↗
PubMed2003

Pharmacogenetics and disease genetics of complex diseases.

Advances in technologies and the availability of a single nucleotide polymorphism (SNP) map are beginning to show the true potential for the human genome project to affect patient healthcare. A whole genome scan, the use of 100000-300000 SNPs across the genome, is now possible. Use of traditional approaches and the whole genome scan will result in identification of disease susceptibility genes and development of many new treatments in the longer term. In the shorter term, the goal will be to predict those patients at risk to experience an adverse reaction or those with a high probability for improved efficacy (i.e. pharmacogenetics). As progress is made in the area of disease genetics and pharmacogenetics, our understanding of disease susceptibility and its interrelationship with drug response will improve, making targeted therapy (i.e. the right drug to the right patient) a reality.

Biotechnology↗
PubMed2003

Successful surgical salvage of partial pancreatic allograft thrombosis.

BACKGROUND: Venous thrombosis remains an important cause of pancreatic graft loss. Nevertheless, reports are scarce of treatment alternatives to complete graft removal. We describe a case of surgical salvage of a partial pancreatic graft thrombosis. METHODS: We used descriptive retrospective analysis. RESULTS: A 36-year-old patient with juvenile-onset diabetes mellitus and previous living related renal transplant received a cadaveric pancreas transplant in the right iliac fossa with enteric exocrine drainage and standard vascular anastomosis. Two days after discharge from the hospital, he presented with severe right upper quadrant pain, nausea, vomiting, fever, and leukocytosis. He was taken to the operating room for exploration. The tail of the pancreas, which was kinked under the gallbladder, was necrotic and excised. The remainder of the pancreas looked normal. The patient recovered well from surgery and was discharged home 7 days later. CONCLUSIONS: Partial pancreatectomy is an acceptable surgical alternative for incomplete graft thrombosis.

Adult↗
PubMed2003

A new species of trypanosome, Trypanosoma desterrensis sp. n., isolated from South American bats.

Trypanosomes isolated from South American bats include the human pathogen Trypanosoma cruzi. Other Trypanosoma spp. that have been found exclusively in bats are not well characterized at the DNA sequence level and we have therefore used the SL RNA gene to differentiate and characterize kinetoplastids isolated from bats in South America. A Trypanosoma sp. isolated from hats in southern Brazil was compared with the geographically diverse isolates T. cruzi marinkellei, T. vespertilionis, and T. dionisii. Analysis of the SL RNA gene repeats revealed size and sequence variability among these bat trypanosomes. We have developed hybridization probes to separate these bat isolates and have analysed the DNA sequence data to estimate their relatedness. A new species, Trypanosoma desterrensis sp. n., is proposed, for which a 5S rRNA gene was also found within the SL RNA repeat.

Animals↗
PubMed2003

Screening for lung cancer: a systematic review and meta-analysis of controlled trials.

BACKGROUND: Lung cancer is a substantial public health problem in western countries. Previous studies have examined different screening strategies for lung cancer but there have been no published systematic reviews. METHODS: A systematic review of controlled trials was conducted to determine whether screening for lung cancer using regular sputum examinations or chest radiography or computed tomography (CT) reduces lung cancer mortality. The primary outcome was lung cancer mortality; secondary outcomes were lung cancer survival and all cause mortality. RESULTS: One non-randomised controlled trial and six randomised controlled trials with a total of 245 610 subjects were included in the review. In all studies the control group received some type of screening. More frequent screening with chest radiography was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, 95% CI 1.00 to 1.23). A non-statistically significant trend to reduced mortality from lung cancer was observed when screening with chest radiography and sputum cytological examination was compared with chest radiography alone (RR 0.88, 95% CI 0.74 to 1.03). Several of the included studies had potential methodological weaknesses. Controlled studies of spiral CT scanning have not been reported. CONCLUSIONS: The current evidence does not support screening for lung cancer with chest radiography or sputum cytological examination. Frequent chest radiography might be harmful. Further methodologically rigorous trials are required before any new screening methods are introduced into clinical practice.

Controlled Clinical Trials as Topic↗
PubMed2003

Systematic assessment of difficult-to-treat asthma.

Five per cent of asthmatics remain symptomatic despite high-dose treatment. The aim of the study was to investigate how often such difficult-to-treat asthma is due to intractable asthma, misdiagnosis, non-adherence with therapy, or psychiatric problems. Difficult asthma was defined as persistence of symptoms despite treatment at step 4 of British guidelines or requirement for long-term oral glucocorticoids (step 5). One-hundred patients with a respiratory physician diagnosis of asthma were investigated in a single tertiary respiratory unit in an open and descriptive study. Twelve of the patients studied did not have asthma and a further seven had additional diagnoses. Of the remainder, 55 had an asthma diagnosis confirmed by demonstration of reversible airflow narrowing or peak flow variability, whilst 20 did not. Non-compliance with prednisolone therapy was more frequent in the 55 with confirmed asthma (nine of 18 prescribed oral prednisolone at a dose of > or = 15 mg x day(-1)) and was not detected in the "unconfirmed asthma" group. There were no other significant differences between these groups. A major psychiatric component was detected in 10 patients. Systematic evaluation of difficult asthma is useful as it can identify alternative or additional diagnoses, psychiatric illness or nonconcordance with therapy in a substantial proportion of cases (32% in the present series).

Administration, Oral↗
PubMed2002

Measurement variability in sleep disorders medicine: the Victorian experience.

BACKGROUND: Surveys of laboratories in North America have documented significant diversity in the working definitions used for reporting respiratory events in sleep studies. AIM: To assess sources of variability in the measurement of sleep-disordered breathing (as defined by the Apnoea-Hypopnoea Index) between sleep laboratories in Victoria, Australia. METHODS: A self-complete written questionnaire was constructed following literature review and interviews with staff at three separate sleep laboratories. The survey was sent to all laboratories listed in Victoria by the Australasian Sleep Association. The first part of the survey related to the type of equipment used to record sleep and other variables during overnight polysomnography and the second part related to the definitions and methods used to report results. RESULTS: Seventeen out of 18 laboratories returned the surveys. There were variations identified in the types of sensors used to measure particular signals. There were also inconsistencies identified in the criteria used to score arousals, apnoeas and hypopnoeas by different laboratories. The variability was greatest for hypopnoea definitions. CONCLUSIONS: There is considerable variation in the methods used to measure and define sleep-disordered breathing between sleep laboratories in Victoria. The extent to which these variations influence the comparability of reported results between laboratories requires further evaluation. The survey findings may assist the process of developing and implementing local guidelines for the performance and reporting of polysomnography.

Clinical Laboratory Techniques↗
PubMed2002

The Victorian CPAP program: is there a need for additional education and support?

BACKGROUND: The Victorian Continuous Positive Airways Pressure (CPAP) Program provides CPAP services to financially disadvantaged individuals with moderate to severe sleep apnoea. AIMS: To evaluate health outcomes in patients referred to the pilot program in order to: (i) assess the magnitude of health benefit from treatment in this highly selected population and (ii) identify patient characteristics or factors related to service provision that may influence outcome. METHODS: We adopted a simple before-after research design. Patients who were referred to the program were recruited from five sleep centres. Questionnaires were administered at baseline and 1 and 3 months after commencing CPAP. Generic and disease-specific quality of life were assessed using the MOS 36-Item Short-form Health Survey and the Sleep Apnoea Quality-of-life Index, respectively. Subjective daytime sleepiness was measured using the Epworth Sleepiness Scale and the Sleep-Wake Activity Inventory. RESULTS: Of the 68 subjects enrolled in the study, 59 were available for follow up. There were significant improvements in daytime sleepiness (P < 0.0005). Treatment-related symptoms had a negative impact on overall disease-specific quality of life, however there were significant improvements in all other domains of disease-specific quality of life (P < 0.0005). Improvements in generic quality of life were small but statistically significant (P < 0.05). Hospital, disease severity, baseline sleepiness, gender and CPAP-machine type were not predictors of outcome (P > 0.05). CONCLUSION: This review of the Victorian CPAP Program identified significant improvements in subjective daytime sleepiness and quality of life, despite the negative impact of treatment-related symptoms. Future research should explore whether services can be modified to help reduce the impact of treatment-related side-effects.

Adolescent↗