Enhancing In Vivo Electroporation Efficiency through Hyaluronidase: Insights into Plasmid Distribution and Optimization Strategies

Electroporation (EP) stands out as a promising non-viral plasmid delivery strategy, although achieving optimal transfection efficiency in vivo remains a challenge. A noteworthy advancement in the field of in vivo EP is the application of hyaluronidase, an enzyme with the capacity to degrade hyaluronic acid in the extracellular matrix, which thereby enhances DNA transfer efficiency by 2- to 3-fold. This paper focuses on elucidating the mechanism of hyaluronidase's impact on transfection efficiency. We demonstrate that hyaluronidase promotes a more uniform distribution of plasmid DNA (pDNA) within skeletal muscle. Additionally, our study investigates the effect of the timing of hyaluronidase pretreatment on EP efficiency by including time intervals of 0, 5, and 30 min between hyaluronidase treatment and the application of pulses. Serum levels of the pDNA-encoded transgene reveal a minimal influence of the hyaluronidase pretreatment time on the final serum protein levels following delivery in both mice and rabbit models. Leveraging bioimpedance measurements, we capture morphological changes in muscle induced by hyaluronidase treatment, which result in a varied pDNA distribution. Subsequently, these findings are employed to optimize EP electrical parameters following hyaluronidase treatment in animal models. This paper offers novel insights into the potential of hyaluronidase in enhancing the effectiveness of in vivo EP, as well as guides optimized electroporation strategies following hyaluronidase use.

Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms

Photoacclimation by strains of Haslea "blue" diatom species H. ostrearia and H. silbo sp. nov. ined. was investigated with rapid light curves and induction-recovery curves using fast repetition rate fluorescence. Cultures were grown to exponential phase under 50 µmol m^-2 s^-1 photosynthetic available radiation (PAR) and then exposed to non-sequential rapid light curves where, once electron transport rate (ETR) had reached saturation, light intensity was decreased and then further increased prior to returning to near growth light intensity. The non-sequential rapid light curve revealed that ETR was not proportional to the instantaneously applied light intensity, due to rapid photoacclimation. Changes in the effective absorption cross sections for open PSII reaction centres (σ_PSII') or reaction centre connectivity (ρ) did not account for the observed increases in ETR under extended high light. σ_PSII' in fact decreased as a function of a time-dependent induction of regulated excitation dissipation Y(NPQ), once cells were at or above a PAR coinciding with saturation of ETR. Instead, the observed increases in ETR under extended high light were explained by an increase in the rate of PSII reopening, i.e. Q_A^- oxidation. This acceleration of electron transport was strictly light dependent and relaxed within seconds after a return to low light or darkness. The time-dependent nature of ETR upregulation and regulated NPQ induction was verified using induction-recovery curves. Our findings show a time-dependent induction of excitation dissipation, in parallel with very rapid photoacclimation of electron transport, which combine to make ETR independent of short-term changes in PAR. This supports a selective advantage for these diatoms when exposed to fluctuating light in their environment.

Maximum profile likelihood estimation of differential equation parameters through model based smoothing state estimates

Statistical inference for biochemical models often faces a variety of characteristic challenges. In this paper we examine state and parameter estimation for the JAK-STAT intracellular signalling mechanism, which exemplifies the implementation intricacies common in many biochemical inference problems. We introduce an extension to the Generalized Smoothing approach for estimating delay differential equation models, addressing selection of complexity parameters, choice of the basis system, and appropriate optimization strategies. Motivated by the JAK-STAT system, we further extend the generalized smoothing approach to consider a nonlinear observation process with additional unknown parameters, and highlight how the approach handles unobserved states and unevenly spaced observations. The methodology developed is generally applicable to problems of estimation for differential equation models with delays, unobserved states, nonlinear observation processes, and partially observed histories.

Yes and Lyn play a role in nuclear translocation of the epidermal growth factor receptor

The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR antibody that has been approved for use in oncology. Previously we investigated mechanisms of resistance to cetuximab using a model derived from the non-small cell lung cancer line NCI-H226. We demonstrated that cetuximab-resistant clones (Ctx^R) had increased nuclear localization of the EGFR. This process was mediated by Src family kinases (SFK), and nuclear EGFR played a role in resistance to cetuximab. To better understand SFK mediated nuclear translocation of EGFR, we investigated which SFK member(s) controlled this process as well as the EGFR tyrosine residues that are involved. Analyses of mRNA and protein expression indicated up-regulation of the SFK members Yes and Lyn in all Ctx^R clones. Further, immunoprecipitation analysis revealed that EGFR interacts with Yes and Lyn in Ctx^R clones, but not in cetuximab-sensitive (Ctx^S) parental cells. Using RNAi interference, we found that knockdown of either Yes or Lyn led to loss of EGFR translocation to the nucleus. Conversely, overexpression of Yes or Lyn in low nuclear EGFR expressing Ctx^S parental cells led to increased nuclear EGFR. Chromatin immunoprecipitation (ChIP) assays confirmed nuclear EGFR complexes associated with the promoter of the known EGFR target genes B-Myb and iNOS. Further, all Ctx^R clones exhibited up-regulation of B-Myb and iNOS at the mRNA and protein levels. siRNAs directed at Yes or Lyn led to decreased binding of EGFR complexes to the B-Myb and iNOS promoters based on ChIP analyses. SFKs have been shown to phosphorylate EGFR on tyrosines 845 and 1101 (Y845 and Y1101) and mutation of Y1101, but not Y845, impaired nuclear entry of the EGFR. Taken together, our findings demonstrate that Yes and Lyn phosphorylate EGFR at Y1101 which influences EGFR nuclear translocation in this model of cetuximab resistance.

Dasatinib sensitizes KRAS mutant colorectal tumors to cetuximab

KRAS mutation is a predictive biomarker for resistance to cetuximab (Erbitux®) in metastatic colorectal cancer (mCRC). This study sought to determine if KRAS mutant CRC lines could be sensitized to cetuximab using dasatinib (BMS-354825, sprycel®) a potent, orally bioavailable inhibitor of several tyrosine kinases, including the Src Family Kinases. We analyzed 16 CRC lines for: 1) KRAS mutation status, 2) dependence on mutant KRAS signaling, 3) expression level of EGFR and SFKs. From these analyses, we selected three KRAS mutant (LS180, LoVo, and HCT116) cell lines, and two KRAS wild type cell lines (SW48 and CaCo2). In vitro, using Poly-D-Lysine/laminin plates, KRAS mutant cell lines were resistant to cetuximab whereas parental controls showed sensitivity to cetuximab. Treatment with cetuximab and dasatinib showed a greater anti-proliferative effect on KRAS mutant line as compared to either agent alone both in vitro and in vivo. To investigate potential mechanisms for this anti-proliferative response in the combinatorial therapy we performed Human Phospho-kinase Antibody Array analysis measuring the relative phosphorylation levels of phosphorylation of 39 intracellular proteins in untreated, cetuximab, dasatinib or the combinatorial treatment in LS180, LoVo and HCT116 cells. The results of this experiment showed a decrease in a broad spectrum of kinases centered on the β-catenin pathway, the classical MAPK pathway, AKT/mTOR pathway and the family of STAT transcription factors when compared to the untreated control or monotherapy treatments. Next we analyzed tumor growth with cetuximab, dasatinib or the combination in vivo. KRAS mutant xenografts showed resistance to cetuximab therapy, whereas KRAS wild type demonstrated an anti-tumor response when treated with cetuximab. KRAS mutant tumors exhibited minimal response to dasatinib monotherapy. However, as in vitro, KRAS mutant lines exhibited a response to the combination of cetuximab and dasatinib. Combinatorial treatment of KRAS mutant xenografts resulted in decreased cell proliferation as measured by Ki67 and higher rates of apoptosis as measured by TUNEL. The data presented herein indicate that dasatinib can sensitize KRAS mutant CRC tumors to cetuximab and may do so by altering the activity of several key-signaling pathways. Further, these results suggest that signaling via the EGFR and SFKs may be necessary for cell proliferation and survival of KRAS mutant CRC tumors. This data strengthen the rationale for clinical trials in this genetic setting combining cetuximab and dasatinib.

Comparison of histidine-tryptophan-ketoglutarate and University of Wisconsin preservation in renal transplantation

Histidine-tryptophan-ketoglutarate (HTK) is replacing University of Wisconsin (UW) solution as the preservation fluid for renal allografts in many centers, but recent large-scale data to support this transition are lacking. We conducted a retrospective analysis of patient and graft outcomes after renal transplantation at our center, comparing 475 consecutive living donor and 317 deceased donor transplants since the adoption of HTK with equal numbers of grafts preserved using UW solution. Data collected included donor and recipient age, race, sex, comorbidities and graft ischemia time. Graft and patient survival, as well as the incidence of delayed graft function (DGF), were studied by Kaplan-Meier and Cox regression analysis. No significant difference was seen in either patient or graft survival. Deceased donor kidneys in the HTK group had a higher incidence of DGF than the UW cohort, whereas this trend was reversed in the case of living donor organs. In multivariate analysis, HTK was associated with a significant risk reduction on the incidence of DGF. Prolonged preservation with HTK compared to UW was not associated with excess risk to the graft or patient. In summary, HTK demonstrated efficacy similar to UW in terms of patient and graft survival.

An iatrogenic enchondroma? An unusual X-ray finding

In this unusual case, accumulation of silver nitrate used to treat over-granulation in a finger injury led to a near-misdiagnosis of a bony tumour on X-ray. This underlines the need to support X-ray results with a full clinical assessment.

Financial implications of pancreas transplant complications: a business case for quality improvement

We quantified the financial implications of surgical complications following pancreas transplantation. We reviewed medical and financial records of 49 pancreas transplant recipients at the University of Michigan Health System (UMHS) between 1/6/2002 and 11/22/2004. The association of donor, transplant recipient and financial variables was assessed. The median costs to UMHS of procedures and follow-up were $92,917 for recipients without surgical complications versus $108,431 when a surgical complication occurred, a difference of $15,514 (p = 0.03). Median reimbursement by the payer was $17,363 higher in patients with a surgical complication (p = 0.001). Similar trends (higher insurer costs) were noted when stratifying by payer (public and private) and specific procedure (SPK and PAK). All parties (patient, physician, payer and medical center) should benefit from quality improvement, with payers having a financial interest in pancreas transplant surgical quality initiatives.

Risk factors for urinary complications after renal transplantation

Urinary complications are common following renal transplantation. The aim of this study is to evaluate the risk factors associated with renal transplant urinary complications. We collected data on 1698 consecutive renal transplants patients. The association of donor, transplant and recipient characteristics with urinary complications was assessed by univariable and multivariable Cox proportional hazards models, fitted to analyze time-to-event outcomes of urinary complications and graft failure. Urinary complications were observed in 105 (6.2%) recipients, with a 2.8% ureteral stricture rate, a 1.7% rate of leak and stricture, and a 1.6% rate of urine leaks. Seventy percent of these complications were definitively managed with a percutaneous intervention. Independent risk factors for a urinary complication included: male recipient, African American recipient, and the "U"-stitch technique. Ureteral stricture was an independent risk factor for graft loss, while urinary leak was not. Laparoscopic donor technique (compared to open living donor nephrectomy) was not associated with more urinary complications. Our data suggest that several patient characteristics are associated with an increased risk of a urinary complication. The U-stitch technique should not be used for the ureteral anastomosis.

ICD-10 codes are a valid tool for identification of pneumonia in hospitalized patients aged > or = 65 years

This study examines the validity of using ICD-10 codes to identify hospitalized pneumonia cases. Using a case-cohort design, subjects were randomly selected from monthly cohorts of patients aged > or = 65 years discharged from April 2000 to March 2002 from two large tertiary Australian hospitals. Cases had ICD-10-AM codes J10-J18 (pneumonia); the cohort sample was randomly selected from all discharges, frequency matched to cases by month. Codes were validated against three comparators: medical record notation of pneumonia, chest radiograph (CXR) report and both. Notation of pneumonia was determined for 5098/5101 eligible patients, and CXR reports reviewed for 3349/3464 (97%) patients with a CXR. Coding performed best against notation of pneumonia: kappa 0.95, sensitivity 97.8% (95% CI 97.1-98.3), specificity 96.9% (95% CI 96.2-97.5), positive predictive value (PPV) 96.2% (95% CI 95.4-97.0) and negative predictive value (NPV) 98.2% (95% CI 97.6-98.6). When medical record notation of pneumonia is used as the standard, ICD-10 codes are a valid method for retrospective ascertainment of hospitalized pneumonia cases and appear superior to use of complexes of symptoms and signs, or radiology reports.

Who pays for biliary complications following liver transplant? A business case for quality improvement

We use biliary complication following liver transplantation to quantify the financial implications of surgical complications and make a case for surgical improvement initiatives as a sound financial investment. We reviewed the medical and financial records of all liver transplant patients at the UMHS between July 1, 2002 and June 30, 2005 (N = 256). The association of donor, transplant, recipient and financial data points was assessed using both univariable (Student's t-test, a chi-square and logistic regression) and multivariable (logistic regression) methods. UMHS made a profit of $6822 +/- 39087 on patients without a biliary complication while taking a loss of $5742 +/- 58242 on patients with a biliary complication (p = 0.04). Reimbursement by the payer was $5562 higher in patients with a biliary complication compared to patients without a biliary complication (p = 0.001). Using multivariable logistic regression analysis, the two independent risk factors for a negative margin included private insurance (compared to public) (OR 1.88, CI 1.10-3.24, p = 0.022) and biliary leak (OR = 2.09, CI 1.06-4.13, p = 0.034). These findings underscore the important impact of surgical complications on transplant finances. Medical centers have a financial interest in transplant surgical quality improvement, but payers have the most to gain with improved surgical outcomes.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

The genetic diversity of Brazilian Trypanosoma cruzi isolates and the phylogenetic positioning of zymodeme 3, based on the internal transcribed spacer of the ribosomal gene

There is a high level of genetic diversity among the clinical isolates of the taxon Trypanosoma cruzi. The results of recent studies on well defined gene loci have revealed that T. cruzi can be divided into two major phylogenetic lineages, designated T. cruzi I and T. cruzi II. Further intra-lineage polymorphisms were explored, in clinical isolates from five representative regions of Brazil, using the internal transcribed spacers that flank the 5.8S ribosomal RNA gene. These regions were amplified in a PCR and the products were digested with six restriction enzymes before being subjected to RFLP analysis in polyacrylamide gels. The results were used to construct a complex evolutionary tree, in which the isolates were clustered into two major phylogenetic lineages with a low level of similarity. To investigate the evolutionary relationships between the isolates, the PCR products were cloned and sequenced. The results of the subsequent phylogenetic analysis confirmed the presence of the two major groups of T. cruzi and showed that zymodeme 3, a third iso-enzymatic sub-group, is closer to T. cruzi I than to T. cruzi II.

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.

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.

A randomized trial of peak-flow and symptom-based action plans in adults with moderate-to-severe asthma

OBJECTIVE

Peak flow meters (PFM) continue to be recommended as an important part of asthma self-management plans. It remains unclear if there is an advantage in using PFM in people with moderate-to severe asthma who are not poor perceivers of bronchoconstriction.

METHODOLOGY

Prospective, randomized controlled trial of 134 adults with moderate-to-severe asthma who did not have evidence of poor perception of bronchoconstriction on histamine challenge testing, who were recruited from inpatients and outpatients of a university teaching hospital. Comparison was made over 12 months of the effectiveness of written action plans using either peak flow monitoring or symptoms to guide management. Subjects were contacted at monthly intervals by telephone for reinforcement and evaluation of use of the action plans, and to provide ongoing education. Spirometry and PD20 histamine were measured at 3-monthly intervals. Measures of health care utilization and morbidity (asthma exacerbations; hospitalizations; emergency department (ED) visits; days absent from work or school due to asthma; medication use and a self-rating of asthma severity) were made monthly. A psychosocial questionnaire (attitudes and beliefs, state-trait anxiety, denial) was given at entry and at 12-months or at withdrawal from the study.

RESULTS

There were significant improvements for both groups for hospitalizations, ED visits, days off from school or work, and PD20 histamine, but no between-group differences. Appropriate use of action plans was 85% in the symptoms group and 86% in the PFM group. For all subjects, those who subsequently had an ED visit had significantly higher levels of denial (P=0.04) and lower scores for self-confidence (P=0.04), compared to those who did not have an ED visit.

CONCLUSIONS

Use of written action plans, combined with regular contact to reinforce self-management, improved airway reactivity and reduced health care utilization. However, use of PFM was not superior to symptom-based plans.

Kinetoplast DNA minicircles of phloem-restricted Phytomonas associated with wilt diseases of coconut and oil palms have a two-domain structure

We report the cloning and sequencing of the first minicircle from a phloem-restricted, pathogenic Phytomonas sp. (Hart 1) isolated from a coconut palm with hartrot disease. The minicircle possessed a two-domain structure of two conserved regions, each containing three conserved sequence blocks (CSB). Based on the sequence around CSB 3 from Hart 1, PCR primers were designed to allow specific amplification of Phytomonas minicircles. This primer pair demonstrated specificity for at least six groups of plant trypanosomatids and did not amplify from insect trypanosomatids. The PCR results were consistent with a two-domain structure for other plant trypanosomatids.

Hope and harm: a delicate balance. Death and dying in multicultural Australia

Australia's cultural diversity poses challenges to healthcare professionals, particularly in caring for dying people. Different cultures have different attitudes to the role of the doctor, patient autonomy and disclosure of diagnosis and prognosis. Doctors need to recognise the cultural and spiritual needs of patients and their families.

Two sequence classes of kinetoplastid 5S ribosomal RNA gene revealed among bodonid spliced leader RNA gene arrays

The spliced leader RNA genes of Bodo saltans, Cryptobia helicis and Dimastigella trypaniformis were analyzed as molecular markers for additional taxa within the suborder Bodonina. The non-transcribed spacer regions were distinctive for each organism, and 5S rRNA genes were present in Bodo and Dimastigella but not in C. helicis. Two sequence classes of 5S rRNA were evident from analysis of the bodonid genes. The two classes of 5S rRNA genes were found in other Kinetoplastids independent of co-localization with the spliced leader RNA gene.

Seasonal changes in temperature and light drive acclimation of photosynthetic physiology and macromolecular content in Lobaria pulmonaria

Lobaria pulmonaria (L.) Hoffm. is an epiphytic lichen common to temperate deciduous forests where it copes with large changes in temperature and light levels through repeated annual cycles. Samples of L. pulmonaria were taken from a deciduous forest in southeastern Canada at 35-day intervals from February 1999 to February 2000 and also from a rare population in an evergreen forest in March and August 1999. At field-ambient temperatures and light levels, the realised photosystem II (PSII) electron transport was low both in the summer and winter, with transient peaks in the spring and autumn. In contrast, the seasonal pattern of potential electron transport measured at a fixed 20 degrees C peaked in winter, showing the importance of temperature in driving photosynthesis to low levels in the winter despite an acclimation of electron-transport potential to exploit the high ambient light. Realised gross CO2 uptake was correlated with PSII electron transport at mechanistically plausible rates at all sampling sites in the summer but not in the winter, indicating electron diversion away from CO2 fixation in the winter. Chlorophyll content was highest in the dark summer months. The amount of ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCO) large subunit (LSU) was highest in spring. Changes in the level of this hyperabundant protein and in the activity of PSII maintained a relatively constant rate of maximum CO2 uptake per RuBisCO LSU from April through November, despite great changes in the seasonal light and temperature. L. pulmonaria acclimates between light and temperature stress in the winter months to light-limitation in the dark summer months. Transition intervals in the spring and autumn, with warm, bright and wet conditions, are likely the most amenable times for growth.

Burnout among American surgeons

BACKGROUND

The long-term consequences of stress on the surgeon are unknown. One manifestation of stress is burnout. The purpose of this study was to measure the prevalence of burnout in actively practicing American surgeons.

METHODS

The Maslach Burnout Inventory and a questionnaire of our own design were sent to 1706 graduates of various University of Michigan surgical residencies (1222) and members of the Midwest Surgical Association (484). The response rate was 44%. Responses from 582 actively practicing surgeons were the sample used for analysis.

RESULTS

Thirty-two percent of actively practicing surgeons showed "high" levels of emotional exhaustion, 13% showed "high" levels of depersonalization, and 4% showed evidence for low personal accomplishment. Younger surgeons were more susceptible to burnout (r = -0.28, P <.01). Burnout was not related to caseload, practice setting, or percent of patients insured by a health maintenance organization. Important etiologic factors were a sense that work was "overwhelming" (r = 0.61, P <.01), a perceived imbalance between career, family, and personal growth (r = -0.56), P <.01), perceptions that career was unrewarding (r = -0.42, P <.01), and lack of autonomy or decision involvement (r = -0.39, P <.01). A strong association was noted between burnout elements and a desire to retire early (r = 0.50, P <.01).

CONCLUSIONS

Burnout is an important problem for actively practicing American surgeons. These data could be used to modify existing surgical training curricula or as an aid to surgical leadership when negotiating about the surgical work environment.

Impact of different criteria for defining hypopneas in the apnea-hypopnea index

OBJECTIVES

To explore the effect of using different scoring criteria for hypopneas in the scoring of polysomnographic studies: (1) by estimating the level of agreement between apnea-hypopnea index (AHI) scores derived from different scoring methods, and (2) by examining the effect on the point prevalence of disease using different threshold values of the AHI.

DESIGN

Retrospective analysis of 48 diagnostic polysomnographic records.

SETTING

Tertiary-hospital sleep-disorders clinic.

MEASUREMENTS

AHIs were derived from three different methods for scoring hypopneas. The hypopnea definitions used incorporated different combinations and threshold values of respiratory signal changes in addition to differences in the requirement for associated oxygen desaturation or arousal. The level of agreement between different scoring methods was assessed by constructing Bland-Altman plots and calculating intraclass correlation coefficients (ICCs). kappa statistics were used to assess agreement between the different methods using varying thresholds of AHI to categorize sleep apnea (AHI > 5, AHI > 15, and AHI > 20).

RESULTS

The random-effects ICC for the three methods was 0.89, suggesting that the different scoring methods tended to rank patients fairly consistently. However, the point prevalence of disease estimated by using different thresholds of AHI was found to vary depending on the method used to score sleep studies (kappa, 0.30 to 0.95).

CONCLUSIONS

These findings have implications for case finding, population-prevalence estimates, and grading of disease severity for access to government-funded continuous positive airway pressure services. Guidelines for standardizing the measurement and reporting of sleep studies in clinical practice should be implemented.

Randomized controlled trial of hand-assisted laparoscopic versus open surgical live donor nephrectomy

BACKGROUND

Laparoscopic live donor nephrectomy for renal transplantation is being performed in increasing numbers with the goals of broadening organ supply while minimizing pain and duration of convalescence for donors. Relative advantages in terms of recovery provided by laparoscopy over standard open surgery have not been rigorously assessed. We hypothesized that laparoscopic as compared with open surgical live donor nephrectomy provides briefer, less intense, and more complete convalescence.

METHODS

Of 105 volunteer, adult, potential living-renal donors interested in the laparoscopic approach, 70 were randomly assigned to undergo either hand-assisted laparoscopic or open surgical live donor nephrectomy at a single referral center. Objective data and subjective recovery information obtained with telephone interviews and validated questionnaires administered 2 weeks, 6 weeks, and 6-12 months postoperatively were compared between the 23 laparoscopic and 27 open surgical patients.

RESULTS

There was 47% less analgesic use (P=0.004), 35% shorter hospital stay (P=0.0001), 33% more rapid return to nonstrenuous activity (P=0.006), 23% sooner return to work (P=0.037), and 73% less pain 6 weeks postoperatively (P=0.004) in the laparoscopy group. Laparoscopic patients experienced complete recovery sooner (P=0.032) and had fewer long-term residual effects (P=0.0015).

CONCLUSIONS

Laparoscopic donor nephrectomy is associated with a briefer, less intense, and more complete convalescence compared with the open surgical approach.