Efficacy and cost of video-assisted thoracoscopic partial pleurectomy versus talc pleurodesis in patients with malignant pleural mesothelioma (MesoVATS): an open-label, randomised, controlled trial

BACKGROUND

Malignant pleural mesothelioma incidence continues to rise, with few available evidence-based therapeutic options. Results of previous non-randomised studies suggested that video-assisted thoracoscopic partial pleurectomy (VAT-PP) might improve symptom control and survival. We aimed to compare efficacy in terms of overall survival, and cost, of VAT-PP and talc pleurodesis in patients with malignant pleural mesothelioma.

METHODS

We undertook an open-label, parallel-group, randomised, controlled trial in patients aged 18 years or older with any subtype of confirmed or suspected mesothelioma with pleural effusion, recruited from 12 hospitals in the UK. Eligible patients were randomly assigned (1:1) to either VAT-PP or talc pleurodesis by computer-generated random numbers, stratified by European Organisation for Research and Treatment of Cancer risk category (high vs low). The primary outcome was overall survival at 1 year, analysed by intention to treat (all patients randomly assigned to a treatment group with a final diagnosis of mesothelioma). This trial is registered with ClinicalTrials.gov, number NCT00821860.

FINDINGS

Between Oct 24, 2003, and Jan 24, 2012, we randomly assigned 196 patients, of whom 175 (88 assigned to talc pleurodesis, 87 assigned to VAT-PP) had confirmed mesothelioma. Overall survival at 1 year was 52% (95% CI 41-62) in the VAT-PP group and 57% (46-66) in the talc pleurodesis group (hazard ratio 1·04 [95% CI 0·76-1·42]; p=0·81). Surgical complications were significantly more common after VAT-PP than after talc pleurodesis, occurring in 24 (31%) of 78 patients who completed VAT-PP versus ten (14%) of 73 patients who completed talc pleurodesis (p=0·019), as were respiratory complications (19 [24%] vs 11 [15%]; p=0·22) and air-leak beyond 10 days (five [6%] vs one [1%]; p=0·21), although not significantly so. Median hospital stay was longer at 7 days (IQR 5-11) in patients who received VAT-PP compared with 3 days (2-5) for those who received talc pleurodesis (p<0·0001).

INTERPRETATION

VAT-PP is not recommended to improve overall survival in patients with pleural effusion due to malignant pleural mesothelioma, and talc pleurodesis might be preferable considering the fewer complications and shorter hospital stay associated with this treatment.

FUNDING

BUPA Foundation.

Efficacy and cost of video-assisted thoracoscopic partial pleurectomy versus talc pleurodesis in patients with malignant pleural mesothelioma (MesoVATS): an open-label, randomised, controlled trial

BACKGROUND

Malignant pleural mesothelioma incidence continues to rise, with few available evidence-based therapeutic options. Results of previous non-randomised studies suggested that video-assisted thoracoscopic partial pleurectomy (VAT-PP) might improve symptom control and survival. We aimed to compare efficacy in terms of overall survival, and cost, of VAT-PP and talc pleurodesis in patients with malignant pleural mesothelioma.

METHODS

We undertook an open-label, parallel-group, randomised, controlled trial in patients aged 18 years or older with any subtype of confirmed or suspected mesothelioma with pleural effusion, recruited from 12 hospitals in the UK. Eligible patients were randomly assigned (1:1) to either VAT-PP or talc pleurodesis by computer-generated random numbers, stratified by European Organisation for Research and Treatment of Cancer risk category (high vs low). The primary outcome was overall survival at 1 year, analysed by intention to treat (all patients randomly assigned to a treatment group with a final diagnosis of mesothelioma). This trial is registered with ClinicalTrials.gov, number NCT00821860.

FINDINGS

Between Oct 24, 2003, and Jan 24, 2012, we randomly assigned 196 patients, of whom 175 (88 assigned to talc pleurodesis, 87 assigned to VAT-PP) had confirmed mesothelioma. Overall survival at 1 year was 52% (95% CI 41-62) in the VAT-PP group and 57% (46-66) in the talc pleurodesis group (hazard ratio 1·04 [95% CI 0·76-1·42]; p=0·81). Surgical complications were significantly more common after VAT-PP than after talc pleurodesis, occurring in 24 (31%) of 78 patients who completed VAT-PP versus ten (14%) of 73 patients who completed talc pleurodesis (p=0·019), as were respiratory complications (19 [24%] vs 11 [15%]; p=0·22) and air-leak beyond 10 days (five [6%] vs one [1%]; p=0·21), although not significantly so. Median hospital stay was longer at 7 days (IQR 5-11) in patients who received VAT-PP compared with 3 days (2-5) for those who received talc pleurodesis (p<0·0001).

INTERPRETATION

VAT-PP is not recommended to improve overall survival in patients with pleural effusion due to malignant pleural mesothelioma, and talc pleurodesis might be preferable considering the fewer complications and shorter hospital stay associated with this treatment.

FUNDING

BUPA Foundation.

If at first you do not succeed, think again!

The authors describe a case of platypnoea orthodeoxia syndrome in an 83-year-old man with a fenestrated atrial septal defect and severe coronary artery disease. The patient had been admitted to hospital six times in the previous year with acute breathlessness, attributed to paroxysmal atrial fibrillation. The patient's symptoms resolved completely following surgical repair of the defect and coronary artery bypass grafting.

Predicting survival in potentially curable lung cancer patients

Lung cancer is the most common cause of cancer death with unchanged mortality for 50 years. Only localized nonsmall-cell lung cancer (NSCLC) is curable. In these patients it is essential to accurately predict survival to help identify those that will benefit from treatment and those at risk of relapse. Despite needing this clinical information, prospective data are lacking. We therefore prospectively identified prognostic factors in patients with potentially curable lung cancer. Over 2 years, 110 consecutive patients with confirmed localized NSCLC (stages 1-3A) were recruited from a single tertiary center. Prognostic factors investigated included age, gender, body mass index (BMI), performance status, comorbidity, disease stage, quality of life, and respiratory physiology. Patients were followed up for 3-5 years and mortality recorded. The data were analyzed using survival analysis methods. Twenty-eight patients died within 1 year, 15 patients died within 2 years, and 11 patients died within 3 years postsurgery. Kaplan-Meier survival estimates show a survival rate of 51% at 3 years. Factors significantly (p < 0.05) associated with poor overall survival were age at assessment, diabetes, serum albumin, peak VO(2) max, shuttle walk distance, and predicted postoperative transfer factor. In multiple-variable survival models, the strongest predictors of survival overall were diabetes and shuttle walk distance. The results show that potentially curable lung cancer patients should not be discriminated against with respect to weight and smoking history. Careful attention is required when managing patients with diabetes. Respiratory physiologic measurements were of limited value in predicting long-term survival after lung cancer surgery.

Single-lung transplant complicated by unexpected explant carcinoma: a management dilemma

Interstitial pneumonia is well known to increase the risk of lung cancer. We describe a young man who underwent single-lung transplantation for confirmed usual interstitial pneumonia and who was unexpectedly found to have multifocal adenocarcinoma in the explanted lung. Induction immunosuppression therapy was decreased and full screening for further tumor development was undertaken. Post-operatively further consolidative changes developed in the remaining native lung and, after diagnosis and staging, a native pneumonectomy was performed for adenocarcinoma. The good early outcome and management dilemmas are discussed, together with a review of the literature.

Lithium-induced nephrogenic diabetes insipidus after coronary artery bypass

We present a case of nephrogenic diabetes insipidus that occurred after on-pump coronary artery bypass grafting in a patient taking long-term lithium carbonate. Lithium toxicity (2.79 mmol/L) was identified on postoperative day 9. Serum sodium peaked at 175 mmol/L on postoperative day 21. Serum osmolality peaked at 384 mOsm/kg H2O, with a urinary osmolality of 403 mOsm/kg H2O. The patient was ultimately managed with hemofiltration and high-dose 1-desamino-8-D-arginine-vasopressin. Recommendations are made based on our experience of this case. In patients on long-term lithium therapy, the potentially life-threatening complication of lithium-induced nephrogenic diabetes insipidus should be specifically anticipated and managed.

The incidence and impact of low body mass index on patients with operable lung cancer

BACKGROUND & AIMS

To prospectively assess the nutritional status of patients referred for lung cancer surgery, as well as to assess the prognostic value of nutritional status in determining the surgical outcome.

METHODS

One hundred and forty-six patients with potentially operable lung cancer were recruited. Loss of appetite and weight loss were recorded. All patients had serum albumin levels and body mass index (BMI) measured. Surgical outcome were noted.

RESULTS

Mean age was 69 (range 42-85) years; 29/146 were not referred for surgery. Eight patients underwent failed thoracotomy. In the remaining 109 patients, mean BMI was 26. Seven patients had BMI of 19 or less. Forty-four patients had ideal body weight. The majority of patients (n=58) were overweight. Mean serum albumin was 37g/l and lower than 30g/l in 5 cases. There were 4% postoperative deaths and 32% with poor surgical outcome. There was no statistical difference in mean BMI, serum albumin, loss of appetite or weight loss between the two outcome groups.

CONCLUSION

BMI is usually well preserved in patients with operable lung cancer. There was no association between low BMI, low serum albumin, loss of appetite or weight loss, and postoperative death or poor surgical outcome in this study.

The effect of lung resection on pulmonary function and exercise capacity in lung cancer patients

OBJECTIVE

Prospectively to evaluate the effects of lung resection on lung function (as measured via spirometry) and exercise capacity (as measured via shuttle-walk test) in lung cancer patients.

METHODS

We conducted pulmonary function tests and the shuttle-walk test with 110 consecutive patients, before and 1 month, 3 months, and 6 months after lobectomy (n = 73) or pneumonectomy (n = 37). All the patients underwent a standard posterolateral thoracotomy. Eighty-eight patients completed all 3 postoperative assessments.

RESULTS

At 6 months after resection, the lobectomy patients had lost 15% of their preoperative forced expiratory volume in the first second (FEV1) (p < 0.001) and 16% of their exercise capacity (p < 0.001), and the pneumonectomy patients had lost 35% of their preoperative FEV(1) (p < 0.001) and 23% of their exercise capacity (p < 0.001).

CONCLUSIONS

Lobectomy patients suffered significant reduction of functional reserve, with almost equal deterioration between lung function and exercise capacity. Pneumonectomy patients had a more substantial loss of functional reserve, and a disproportionate loss of pulmonary function relative to exercise capacity. Therefore, pulmonary function test values considered in isolation may exaggerate the loss of functional exercise capacity in pneumonectomy patients, which is important because many lung cancer patients who require resection for cure are prepared to accept the risks of immediate surgical complications and mortality, but are unwilling to risk long-term poor exercise capacity.

Ventilation-perfusion scintigraphy to predict postoperative pulmonary function in lung cancer patients undergoing pneumonectomy

OBJECTIVE

The American College of Chest Physicians (ACCP) recommends using quantitative perfusion scintigraphy to predict postoperative lung function in lung cancer patients with borderline pulmonary function tests who will undergo pneumonectomy. However, previous scintigraphic data were gathered on small cohorts more than a decade ago, when surgical populations were significantly different with respect to age and sex compared with typical lung cancer patients undergoing pneumonectomy in 2005. We therefore revisited the use of V/Q scintigraphy in pneumonectomy patients in predicting postoperative pulmonary function and the appropriateness of current clinical guidelines.

CONCLUSION

Contrary to ACCP guidelines, we found that ventilation scintigraphy alone provided the best correlation between the predicted and actual postoperative values and recommend its use to predict postoperative lung function. However, scintigraphic techniques may underestimate postoperative lung function, so caution is required before unnecessarily preventing a patient from undergoing surgery that offers a potential cure.

Mesothelioma with non-pleural malignancy: a red herring or just an uncommon pairing?

Malignant pleural mesothelioma (MPM) is a highly aggressive cancer of the pleura with a well-established male predominance and causative link with asbestos exposure. We report four cases of female patients with MPM referred for palliation of symptoms thought to be due to previous non-pleural malignancy.With emerging novel treatments for MPM, this article discusses four unusual cases of MPM occurring in the setting of other malignancy, highlights the importance of considering a primary diagnosis of MPM even in patients with other malignancy, and reinforces the benefits of video-assisted surgical biopsy which allows simultaneous diagnosis and treatment.

VATS lung biopsy in suspected, diffuse interstitial lung disease provides diagnosis, and alters management strategies

OBJECTIVES

In patients with suspected diffuse interstitial lung disease, open lung biopsy is associated with high mortality (16%). This risk is only acceptable if diagnosis is made and management enhanced. We reviewed the role of VATS techniques in this group to determine the morbidity, mortality and outcomes in terms of diagnosis and enhanced management.

METHODS

Over the period of 5 years, 78 patients with suspected diagnosis of diffuse interstitial lung disease on clinical and radiological grounds were referred to a single surgical team. The patients' case notes and histology reports were reviewed retrospectively. Correlation was made with histopathological diagnosis.

RESULTS

All 78 patients had sufficient provision of material for histological analysis. Eight patients had a histological diagnosis not consistent with diffuse interstitial lung disease; in all eight patients, this significantly altered the subsequent management. Of the 70 patients with diffuse lung disease, 26 patients (37.1%) had a histological diagnosis of usual interstitial pneumonia. Thirteen patients (18.6%) had a histological diagnosis of unclassifiable diffuse lung disease despite an adequate biopsy. The remaining 31 patients (44.3%) had other positive histological diagnosis made. A difference between pre-operative clinico-radiological and final histological diagnosis sufficient to change prognosis and definitive management was made in 19 patients (27.1%). The mean and median post-operative stay was 2.8 days and 2 days, respectively. The in-hospital mortality was one patient (1.5%) due to adult respiratory distress syndrome.

CONCLUSIONS

VATS lung biopsy can be performed in this group of patient with low mortality of 1.5%. It provides sufficient material for histological diagnosis in 100% of patients and alters the management and prognosis in a significant number of patients. We propose that the role of VATS and clinico-radiological techniques should be compared in a prospective controlled clinical trial.

The Use of Vacuum-Assisted Closure in the Treatment of Post-transplant Wound Infections: A Case Series

We present 6 cases of the successful use of vacuum-assisted closure dressings as the primary treatment of wound infection after thoracic organ transplantation. In a series of 160 successive transplant operations, deep wound infections developed in 6 patients (3.7%). These all fully resolved over 3 to 29 days with the use of vacuum dressings. We believe vacuum-assisted closure therapy in the context of heart and lung transplantation is effective, well tolerated, and avoids the need for repeated surgical debridement and reconstruction.

Use of quantitative lung scintigraphy to predict postoperative pulmonary function in lung cancer patients undergoing lobectomy

BACKGROUND

In patients with non-small cell lung cancer, the only realistic chance of cure is surgical resection. However, in some of these patients there is such poor respiratory reserve that surgery can result in an unacceptable quality of life. In order to identify these patients, various pulmonary function tests and scintigraphic techniques have been used. The current American College of Physicians and British Thoracic Society guidelines do not recommend the use of quantitative ventilation-perfusion scintigraphy to predict postoperative function in lung cancer patients undergoing lobectomy. These guidelines may have been influenced by previous scintigraphic studies performed over a decade ago. Since then there have been advances in both surgical techniques and scintigraphic techniques, and the surgical population has become older and more female represented.

METHODS

We prospectively performed spirometry and quantitative ventilation-perfusion scintigraphy on 61 consecutive patients undergoing lobectomy for lung cancer. Spirometry was repeated one-month postsurgery. Both a simple segment counting technique alone and scintigraphy were used to predict the postoperative lung function.

RESULTS

There was statistically significant correlation (p < 0.01) between the predicted postoperative lung function using both the simple segment counting technique and the scintigraphic techniques. However, the correlation using simple segment counting was of negligible difference compared to scintigraphy.

CONCLUSIONS

In keeping with current American Chest Physician and British Thoracic Society guidelines, our results suggest that quantitative ventilation-perfusion scintigraphy is not necessary in the preoperative assessment of lung cancer patients undergoing lobectomy. The simple segmenting technique can be used to predict postoperative lung function in lobectomy patients.

Cardiopulmonary exercise tests and lung cancer surgical outcome

STUDY OBJECTIVES

Surgical resection remains the treatment of choice for anatomically resectable non-small cell lung cancer. However, the presence of associated comorbid conditions increases the risk of death and surgical complications. Several studies have evaluated the usefulness of preoperative exercise testing for predicting postoperative morbidity and mortality. The aim of this study was to establish whether exercise testing could predict poor surgical outcome in lung cancer surgery and whether the absolute value or percentage of predicted value is the better predictor of the surgical outcome.

DESIGN

The study was designed as a prospective study.

PATIENTS AND SETTING

One hundred thirty patients with potentially operable lung cancer at Papworth Hospital over 2 years were recruited; of these, 101 underwent curative surgery.

INTERVENTIONS

Spirometry and cardiopulmonary exercise tests were performed for every patient (n = 99), except for two patients with back problems. We also recorded the outcome of surgery, in particular, complications and mortality.

MEASUREMENTS AND RESULTS

Mean maximum oxygen transport at peak exercise (Vo(2)peak) was 18.3 mL/kg/min (SD, 4.7 mL/kg/min), and mean percentage of predicted Vo(2)peak value was 84.4% (SD, 30%). Poor surgical outcome was significantly related to Vo(2)peak percentage of predicted (p < 0.01) but not to the actual oxygen uptake value.

CONCLUSIONS

The use of the percentage of predicted Vo(2)peak value would be a better indicator of surgical outcome, since it predicts the surgical outcome better, and corrects for normal physiologic ranges. The threshold of Vo(2)peak for surgical intervention could be set between 50% and 60% of predicted without excess surgical mortality.

Relationship of shuttle walk test and lung cancer surgical outcome

OBJECTIVE

Surgery remains the treatment of choice in patients with potentially resectable lung carcinoma. Both the British Thoracic Society and American Chest Physician guidelines for the selection of patients with lung cancer surgery suggest the use of a shuttle walk test to predict outcome in patients with borderline lung function. The guidelines suggest that if the patient is unable to walk 250 m during a shuttle walk test, they are high risk for surgery. However, there is no published evidence to support this recommendation. Therefore, we undertook a prospective study to examine the relationship between shuttle walk test and surgical outcome in 139 patients undergoing assessment for possible lung cancer surgery.

METHODS

The shuttle walk test was performed in 139 potentially resectable patients, recruited over a 2 year period, prior to surgery. One hundred and eleven patients underwent surgery. Outcome of surgery, including duration of hospital stay, complication and mortality rates was recorded. Student's t-test was used to compare the shuttle walk distance in patients with good and poor outcome from surgery.

RESULTS

Mean age of patients undergoing surgery was 69 years (42-85). Mean shuttle walk distance was 395 m (145-780), with a mean oxygen desaturation of 4% (0-14) during the test. Sixty nine patients had a good surgical outcome and 34 had a poor outcome. The shuttle walk distance was not statistically different in the two outcome groups.

CONCLUSION

Shuttle walk distance should not be used to predict poor surgical outcome in lung cancer patients, contrary to current recommendations. It is therefore advisable to perform a formal cardiopulmonary exercise test if at all possible. The usefulness of a shuttle walk test might be improved. It could be compared to a predicted value, as for a formal cardiopulmonary exercise test.

Improved survival with VATS pleurectomy-decortication in advanced malignant mesothelioma

AIMS

Malignant mesothelioma is increasing in incidence and no current therapy significantly prolongs survival. Previous surgical strategies involved high-risk open procedures without achieving histologically clear resection margins. We present the results of VATS debulking pleurectomy-decortication in advanced disease.

METHODS

A consecutive series of patients with suspected malignant mesothelioma underwent thoracoscopic assessment to determine the feasibility of decortication, where this was not possible a biopsy alone was taken. Post-operative radiotherapy was administered to port sites, but no other adjuvant therapy was given. The two groups (biopsy only and pleurectomy-decortication) were composed of patients with histologically confirmed mesothelioma [28 and 51 patients, respectively]. The primary endpoint was comparison of actuarial patient survival. Secondary endpoints included post-operative air leak and duration of hospital stay.

RESULTS

The overall actuarial survival was 288 days and 67% of patients had died at the time of data analysis. The groups were matched for patient and tumour-related characteristics including age (66, 64 years, p=0.39) and tumour stage (median IMIG stage 3 [IQR 2-3] both groups, p=0.54). The biopsy only group had fewer air leaks (57, 84%, p=0.01) and a shorter hospital stay (4, 8 days, p=0.03). However, the pleurectomy-decortication group had favourable actuarial survival relative to the biopsy only group (416, 127 days, p<0.001). Multivariate analysis showed early stage (p<0.001), absence of pre-operative fever (p=0.03) and pleurectomy-decortication (p<0.001) as independent predictors of survival.

CONCLUSION

VATS pleurectomy-decortication is feasible in the majority of cases and independently improves survival for patients with advanced malignant mesothelioma.

The Pseudomonas aeruginosa quorum-sensing molecule N-3-(oxododecanoyl)-L-homoserine lactone inhibits T-cell differentiation and cytokine production by a mechanism involving an early step in T-cell activation

The Pseudomonas aeruginosa quorum-sensing molecule N-3-(oxododecanoyl)-L-homoserine lactone (OdDHL) has been reported to have immunomodulatory activity in several systems, although the mechanism of that activity remains to be fully characterized. We demonstrate here, using a defined in vitro model of antigen responses by T-cell receptor (TCR)-transgenic mouse splenic CD4 T cells, that the effect of OdDHL on activation and cytokine production is complete within 4 h of antigen or mitogen stimulation and does not depend on the insertion of OdDHL in the cell membrane, despite a previous report that immunosuppression by homoserine lactones required a minimum acyl chain length of 11 carbons (S. R. Chhabra, C. Harty, D. S. W. Hooi, M. Daykin, B. W. Bycroft, P. Williams, and D. Pritchard, J. Med. Chem. 46:97-104, 2003). We also demonstrate that while OdDHL can have toxic effects on nonlymphoid leukocytes, it does not induce significant cell death in T cells at the concentrations (< or =10 microM) used in these experiments. In addition, we show that primary and secondary antigen-specific cytokine responses are equally susceptible to inhibition by OdDHL and that the compound inhibits the differentiation of both Th1 and Th2 cells. However, the precise balance of cytokine production by CD4 T cells stimulated in the presence of OdDHL varies with both the antigen concentration and its affinity for the transgenic TCR. Thus, conflicting reports of the nature of the immunosuppression by OdDHL may be due in part to the differences in antigen affinity and concentration in different models.

Relationship between pulmonary function and lung cancer surgical outcome

The British Thoracic Society and American College of Chest Physician guidelines outline criteria for investigating patients for lung cancer surgery. However, the guidelines are based on relatively old studies. Therefore, the relationship between pulmonary function test results and surgical outcome were studied prospectively in a large cohort of lung cancer patients. From January 2001 to December 2003, 110 patients underwent surgery for lung cancer. All underwent full lung function testing in order to predict post-operative lung function. The hospital mortality rate was 3% and major complication rate 22%. There was poor overall outcome in 13%. Mean pre-operative lung function values were: forced expiratory volume in one second (FEV1) 2.0 L (79.4% of the predicted value), and carbon monoxide diffusing capacity of the lung (D(L,CO)) 73.6% pred. The mean post-operative lung function values were: FEV1 1.4 L (55.6% pred), and D(L,CO) 51.3% pred. All lung function values were better predictors of poor surgical outcome when expressed as a percentage of the predicted value. Using a threshold of pre-operative FEV1 of 47% pred resulted in the most useful positive and negative predictive probabilities, 0.90 and 0.67, respectively. Lung function values expressed as a percentage of the predicted value are more useful predictors of post-operative outcome than absolute values. The threshold of predicted forced expiratory volume in one second for surgical intervention could be lower (45-50% pred) than is currently accepted without increased mortality.

Effect of lung cancer surgery on quality of life

BACKGROUND

Health related quality of life (HRQOL) after surgery is important, although very limited data are available on the QOL after lung cancer surgery.

METHODS

The effect of surgery on HRQOL was assessed in a prospective study of 110 patients undergoing potentially curative lung cancer surgery at Papworth Hospital, 30% of whom had borderline lung function as judged by forced expiratory volume in 1 second. All patients completed the EORTC QLQ-C30 and LC13 lung cancer module before surgery and again at 1, 3 and 6 months postoperatively.

RESULTS

On average, patients had high levels of functioning and low levels of symptoms. Global QOL had deteriorated significantly 1 month after surgery (p = 0.001) but had returned to preoperative levels by 3 months (p = 0.93). Symptoms had worsened significantly at 1 month after surgery but had returned to baseline levels by 6 months. Low values on the preoperative HRQOL scales were not significantly associated with poor surgical outcome. However, patients with low preoperative HRQOL functioning scales and high preoperative symptom scores were more likely to have poor postoperative (6 months) QOL. The only lung function measurement to show a marginally statistically significant association with quality of life at 6 months after surgery was percentage predicted carbon monoxide transfer factor (Tlco).

CONCLUSION

Although surgery had short term negative effects on quality of life, by 6 months HRQOL had returned to preoperative values. Patients with low HRQOL functioning scales, high preoperative symptom scores, and preoperative percentage predicted Tlco may be associated with worse postoperative HRQOL.

Clinical outcome versus post-mortem finding in thoracic surgery: a 10-year experience

OBJECTIVES

The role of post-mortem following thoracic surgery has not been previously studied. Most importantly, the clinical diagnosis of thoracic surgical mortality cannot be certain unless post-mortem analysis has been performed.

METHODS

Consecutive post-mortem data were collected on 110 patients between 1992 and 2001 (66.3% of all in-hospital thoracic surgical deaths). Clinically attributed causes of death were compared with post-mortem findings.

RESULTS

A total of 4302 thoracic operations were performed during the 10-year period, with overall mortality 3.8%. The mean age was 63.6 years (range 21-87) with 73.6% male. In the 110 patients undergoing post-mortem examination, the operations performed were pneumonectomy 24.5%, lobectomy 14.5%, oesophagectomy 12.7%, lung biopsy 8.2%, pleurectomy/bullectomy 6.4%, decortication 4.5%, lung volume reduction 1.8%, other thoracic 13.6%, other oesophageal 9.1%, and other procedures 4.5%. The mean time to death was 12.5 days (range 0-85). The causes of death were respiratory 47.3%, cardiac 16.4%, multiple organ failure 8.2%, sepsis 6.4%, gastrointestinal 4.5%, haemorrhage/technical failure 10%, and others 7.3%. Post-mortem revealed an unsuspected cause of death in 34 (31%) patients, comprising pulmonary 17, cardiac 5, gastrointestinal 3, haemorrhage/technical failure 2, multiple organ failure 2 and other 5.

CONCLUSION

Post-mortem determined unsuspected diagnoses in a high proportion of patients undergoing thoracic surgery. Post-mortem continues to be the 'gold standard' method for attributing the cause of death. Accurate outcome data following thoracic surgery are essential for proper audit, and hence for improvements in clinical practice to occur.

Acute hydrothorax in CAPD. Eearly thoracoscopic (VATS) intervention allows return to peritoneal dialysis

BACKGROUND/AIMS

Hydrothorax is a complication of continuous ambulatory peritoneal dialysis (CAPD) occurring due to pleuroperitoneal fistulae. Several treatments exist with no consensus as to best management. We report on the largest series of video-assisted thoracoscopic surgery (VATS) treated pleuroperitoneal fistulae yet available.

METHODS

Between 1995 and 2000, we treated 6 CAPD patients for acute right hydrothoraces using VATS. Data pertaining to size and sterility of hydrothoraces, presence of diaphragmatic defects, surgical procedures performed, morbidity and return to CAPD were obtained.

RESULTS

Hydrothoraces were drained in all patients and there were no significant growths on subsequent culture. Fistulae were directly identified and closed in three patients. In the remaining patients, endoclips were placed across the base of small diaphragmatic blebs (the presumed site of communication). Parietal pleurectomy was performed uneventfully in all patients. There was no morbidity, all patients returned to haemodialysis and there have been no recurrences.

CONCLUSIONS

Pleuroperitoneal fistulae produce symptomatic hydrothoraces in CAPD patients. A variety of approaches to the problem have been described. This is the largest series of VATS available and shows the usefulness of this approach in both closing the defect and producing an effective pleurectomy to prevent recurrence.

The surgical treatment of bronchial carcinoma

This article considers the current place of surgery in the treatment of bronchial carcinoma. Aspects of the diagnosis of this condition will be covered, but the main focus falls on the surgical procedures, their complications and the outlook for these patients according to tumour stage.

Vacuum-assisted closure as a treatment modality for infections after cardiac surgery

OBJECTIVE

Wound infections after cardiac surgery carry high morbidity and mortality. A plethora of management strategies have been used to treat such infections. We assessed the impact of vacuum-assisted closure on the management of sternal wound infections in terms of wound healing, duration of vacuum-assisted closure, and cost of treatment.

METHODS

Between November 1998 and June 2001, a total of 27 mediastinal infections were managed with vacuum-assisted closure. Group A (n = 14) had vacuum-assisted closure as the final treatment modality, whereas in group B (n = 13) vacuum-assisted closure was followed by either a myocutaneous flap (n = 8) or primary (n = 5) wound closure. The choice of additional treatment modality was based on wound size.

RESULTS

In group A, 4 patients died and a satisfactorily healed scar was achieved in 64% of cases. Median durations of vacuum-assisted closure and hospital stay in group A were 13.5 days (interquartile range 8.8-32.2 days) and 20 days (interquartile range 16.7-25.2 days), respectively. Mortality was 7.7% in group B, with a treatment failure rate of 15%. Median duration of vacuum-assisted closure in group B was 8 days (interquartile range 5.5-18 days), and median hospital stay was 29 days (interquartile range 25.8-38.2 days). During the year before institution of vacuum-assisted closure, poststernotomy infection (n = 13) was managed with rewiring and closed irrigation system. Treatment during this year failed in 30.7% of cases (n = 4/13), and mortality was also 30.7%. The total cost (hospitalization and treatment) per patient for vacuum-assisted closure was 16,400 dollars, compared with 20,000 dollars for the closed irrigation system treatment.

CONCLUSION

Vacuum-assisted closure, used alone or before other surgical treatment strategies, is an acceptable treatment modality for infections in cardiac surgery with reasonable morbidity, mortality, and cost.

Intraoperative confirmation of ulnar collateral blood flow during radial artery harvesting using the "squirt test"

Hand ischemia is a major concern after radial artery harvesting for coronary revascularization. Although a number of preoperative tests have been described to assess the adequacy of ulnar collateral blood flow, many of them are subjective and unreliable. In addition, the presence of arterial connections between the radial and ulnar systems in the elbow and forearm and variability in forearm angiology imply that assessment of alternative blood supply to the hand can only be made once collateral branches of the radial artery have been divided. We describe a technique for intraoperative assessment of ulnar collateral blood flow after mobilization and division of collateral branches of the radial artery.

Thoracoscopic thoracic duct ligation for traumatic chylothorax

Traumatic chylothorax requires surgical intervention when conservative medical management fails to reduce chyle leakage. This usually entails thoracotomy or laparotomy. We report a case in which successful ligation of a torn thoracic duct was achieved using a video-assisted thoracoscopic technique.

Effect of the blood substitute diaspirin crosslinked hemoglobin in rat mesenteric and human radial collateral arteries

The actions of the blood substitute diaspirin crosslinked hemoglobin (DCLHb) were investigated in rat (small mesenteric artery) and human (radial collateral artery) resistance vessels mounted in a wire myograph for isometric tension recording. DCLHb did not contract resting vessels from rats, but vasoconstrictor responses were observed in isolated arteries and perfused mesenteric beds prestimulated with threshold concentrations of methoxamine. The DCLHb contractile responses were greatly attenuated by N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) or endothelial removal, whereas BQ-123 (endothelin A receptor antagonist), prazosin (alpha1-adrenoceptor antagonist), or indomethacin (cyclooxygenase inhibitor) had no effect. Endothelium-dependent relaxations to carbachol in both rat mesenteric and human radial collateral artery were inhibited by DCLHb. Relaxations to carbachol were studied in the presence of L-NAME or 25 mM KCl to investigate the effect of DCLHb on endothelium-derived hyperpolarizing factor (EDHF) and nitric oxide, respectively. In both rat and human vessels, EDHF-mediated relaxations were not affected by DCLHb preincubation, whereas the nitric oxide component of carbachol-induced relaxations was practically abolished. In conclusion, inhibition of the effects of basal nitric oxide release underpins the vasoconstrictor effects of DCLHb. DCLHb effectively abolishes the nitric oxide component of carbachol-induced relaxation, with no effect on the EDHF-mediated component in both isolated rat mesenteric and human radial collateral arteries.

Tumor necrosis factor alpha increases human cerebral endothelial cell Gb3 and sensitivity to Shiga toxin

Hemolytic uremic syndrome (HUS) is associated with intestinal infection by enterohemorrhagic Escherichia coli strains that produce Shiga toxins. Globotriaosylceramide (Gb3) is the functional receptor for Shiga toxin, and tumor necrosis factor alpha (TNF-alpha) upregulates Gb3 in both human macrovascular umbilical vein endothelial cells and human microvascular brain endothelial cells. TNF-alpha treatment enhanced Shiga toxin binding and sensitivity to toxin. This upregulation was specific for Gb3 species containing normal fatty acids (NFA). Central nervous system (CNS) pathology in HUS could involve cytokine-stimulated elevation of endothelial NFA-Gb3 levels. Differential expression of Gb3 species may be a critical determinant of Shiga toxin toxicity and of CNS involvement in HUS.

The action of diaspirin cross-linked haemoglobin blood substitute on human arterial bypass conduits

BACKGROUND

Immediately available blood substitutes could transform medicine. In coronary artery surgery, vasoconstriction induced by some of these agents could have serious implications. We have examined some of the vasoactive effects of one of these blood substitute, diaspirin cross-linked haemoglobin (DCLHb), on isolated rings of human arterial conduits.

METHODS

Sections of human left internal mammary artery (LIMA) and radial artery (RA) were cut into 3-mm rings, mounted in individual organ baths containing aerated (95% O(2)/5% CO(2)) Krebs-Heinseleit solution at 37 degrees C and attached to isometric strain gauge for measurements of tension. All rings were tested for the presence of endothelium by addition of carbachol to rings pre-contracted with phenylephrine. The relative importance of nitric oxide (NO) in contraction mediated by the addition of DCLHb was studied.

RESULTS

Carbachol relaxed phenylephrine precontracted LIMA by 72.3+/-1.7% and RA by 97+/-0.7% confirming the presence of a functional endothelium. Sodium nitroprusside (SNP) caused complete relaxation of LIMA with an EC(50) value of 2.0+/-0.1x10(-8) M and RA with an EC(50) value of 1. 9+/-0.1x10(8) M. In the presence of DCLHb (10(-7) M), carbachol-induced relaxation was significantly reduced to 46.3+/-0. 7% (P<0.01) and the BC(50) value for SNP relaxation increased to 1. 2+/-0.1x10(-7) M (P<0.01). DCLHb caused rings to contract in the absence of phenylephrine with EC(50) values of 1.6+/-0.1x10(-7) M (LIMA) and 1.8+/-0.1x10(-7) M (RA). Presence of L-NAME (300 microM) caused no alteration in DCLHb-induced contraction.

CONCLUSION

In this study of isolated rings of human vessels, DCLHb causes a significant reduction in relaxation mediated by carbachol and SNP, which is likely to be due to its ability to bind NO. However, it is possible that other mechanisms might contribute to the vasoconstrictor effects of DCLHb and these might be amenable to anti-vasospastic strategies.

Lesson of the week. Unrecognised accidental overdose with diltiazem

Invasive haemodynamic monitoring should be considered when hypotension fails to respond to empirical treatments

Clinical versus actual outcome in cardiac surgery: a post-mortem study

BACKGROUND

Clinical attribution of the cause of death can be misleading, with the only true outcome measure being post-mortem analysis. Despite this there is very little published data on post-mortems following cardiac surgery.

METHODS

Prospective consecutive post-mortem data were collected on 167 patients (84.4% of all in-hospital cardiac surgical deaths) in a single institution. Clinical diagnoses were compared with post-mortem findings.

RESULTS

The mean age at death was 69.8 with 67.6% male. The proportion undergoing coronary artery bypass graft (CABG) alone was 52.1%, valve surgery 18.6%, valve+CABG 19.2% and other procedures 10.1%. The mean time to death was 7.9 days (range 0-87). The causes of death were cardiac 67.7%, gastrointestinal 9.6%, respiratory 8.4%, haemorrhage/technical failure 4.8%, stroke (cerebrovascular accident) 3.6%, multiorgan failure 3.0%, sepsis 1.8%, malignancy 0. 6% and trauma 0.6%. Post-mortem revealed an unsuspected cause of death in 19 (11.4%). These were gastrointestinal (infarction nine, perforation two), cardiac three, adult respiratory distress syndrome two, technical two and pulmonary embolus one. In addition, an unsuspected lung cancer was found in 1 patient who died of cardiac causes. When cardiac deaths were compared with non-cardiac causes the Parsonnet score was higher 20.0 (+/-1.4) vs. 15.3 (+/-1.6), P=0. 07; and a greater proportion tended to have poor ejection fractions (34 vs. 15%), P=0.12. There was no significant difference between the groups in terms of age, sex, operation, hypertension, diabetes, creatinine and body mass.

CONCLUSIONS

Post-mortem can determine unsuspected diagnoses in a significant proportion of cases. Pre-operative risk factors do not correlate with eventual cause of death. Post-mortem still has an important role to play in cardiac surgery.

Videothoracoscopic drainage of mediastinal abscess: an alternative to thoracotomy

A late-presenting high esophageal perforation that resulted in a massive mediastinal abscess and bronchopleural fistula in an elderly moribund patient unfit for radical surgery was successfully drained using a videothoracoscopic technique.

Inhibitory effects of glibenclamide on the contraction of human arterial conduits used in coronary artery bypass surgery

Glibenclamide has been shown to inhibit prostanoid-induced contraction in a number of blood vessel types. In this study, the effects of glibenclamide on the contraction of human peripheral arteries in response to both prostanoid and non-prostanoid agonists were compared and possible mechanisms of action were investigated. Segments of left internal mammary artery (LIMA) and radial artery, taken from patients undergoing coronary artery bypass graft (CABG) surgery, were mounted in organ baths containing physiological saline solution aerated with 95% O2/5% CO2 at 37 degrees C. Contractions were obtained by either the use of a thromboxane analogue (U46619), L-phenylephrine, KCl or CaCl2. The effects of glibenclamide on these contractions were observed and pEC50 values were determined after manipulation of a logistic curve-fitting equation. Concentration-dependent relaxation of U46619-contracted LIMA and radial artery was observed in the presence of glibenclamide, with calculated pEC50 values of 4.2+/-0.17 (n = 7) for LIMA and 3.26+/-0.48 (n = 5) for radial artery. Incubation of both LIMA and radial artery with glibenclamide (50 microM) caused the concentration-response curves for U46619 and L-phenylephrine to shift significantly to the right. Similarly the KCl tension relationship was caused to shift to the right. Finally, glibenclamide (100 microM) also had an inhibitory effect on Ca2+-induced tension in radial artery. These results show that the inhibitory effects of glibenclamide on human peripheral blood vessels are not restricted to prostanoid-induced contractions. Furthermore, evidence has been provided to suggest that these effects might be mediated through an interaction with voltage-sensitive Ca2+ channels.

Mesothelioma--VATS biopsy and lung mobilization improves diagnosis and palliation

OBJECTIVES

Mesothelioma is an increasingly frequent malignancy in which diagnosis is often delayed and disease diagnosed at an advanced stage. Earlier diagnosis and therapeutic intervention that can control recurrent pleural effusion may improve outlook and survival.

METHODS

A prospective series of 25 patients in whom mesothelioma was suspected was referred for histological diagnosis by video assisted-thoracoscopy (VAT) after failure of other methods. At the same operative procedure drainage of pleural effusion, cytoreductive pleurectomy and lung mobilization was performed where possible. Complete follow-up was obtained.

RESULTS

All patients had a histological diagnosis (100%) from the material sent for biopsy. In 23 patients this was mesothelioma, in two patients chronic empyema. All patients undergoing drainage of effusion, cytoreductive pleurectomy and lung mobilization subsequently were diagnosed of having mesothelioma stages III to IV. Fifteen out of 21 who underwent lung mobilization had closure of the pleural space. Post operative air leak in this group was a mean of 5 days (2-12 days). Recurrent effusion occurred in only one patient. Eleven patients remain alive at 1-2 years post operation with no hospital admissions for recurrent pleural effusion. In the six out of 21 who did not have closure of the pleural space, one remained alive 9 months post surgery. Five died within 1-6 months of the procedure. The average number of further hospital admissions for repeat drainage of effusion was 3 (1-6).

CONCLUSIONS

VATs provides adequate tissue for histological diagnosis where other methods fail. At the same operative sitting it provides a therapeutic intervention that allows drainage of effusion cytoreductive pleurectomy and lung mobilization in a significant number of cases. Where the pleural space can be closed this results in significantly fewer hospital admissions and appears to improve quality of life and length of survival. The price is a longer hospital stay due to prolonged air leak.

Current practice in thoracic sympathectomy

Thoracic sympathectomy has been performed for many years. With the recent development of video assisted thoracic surgical techniques the indications for surgery have increased, and the outcome is much better.

Increased levels of advanced glycation endproducts in the lenses and blood vessels of cigarette smokers

BACKGROUND

Advanced glycation endproducts (AGEs) arise from the spontaneous reaction of reducing sugars with the amino groups of macromolecules. AGEs accumulate in tissue as a consequence of diabetes and aging and have been causally implicated in the pathogenesis of several of the end-organ complications of diabetes and aging, including cataract, atherosclerosis, and renal insufficiency. It has been recently proposed that components in mainstream cigarette smoke can react with plasma and extracellular matrix proteins to form covalent adducts with many of the properties of AGEs. We wished to ascertain whether AGEs or immunochemically related molecules are present at higher levels in the tissues of smokers.

MATERIALS AND METHODS

Lens and coronary artery specimens from nondiabetic smokers and nondiabetic nonsmokers were examined by immunohistochemistry, immunoelectron microscopy, and ELISA employing several distinct anti-AGE antibodies. In addition, lenticular extracts were tested for AGE-associated fluorescence by fluorescence spectroscopy.

RESULTS

Immunoreactive AGEs were present at significantly higher levels in the lenses and lenticular extracts of nondiabetic smokers (p < 0.003). Anti-AGE immunogold staining was diffusely distributed throughout lens fiber cells. AGE-associated fluorescence was significantly increased in the lenticular extracts of nondiabetic smokers (p = 0.005). AGE-immunoreactivity was significantly elevated in coronary arteries from nondiabetic smokers compared with nondiabetic nonsmokers (p = 0.015).

CONCLUSIONS

AGEs or immunochemically related molecules are present at higher levels in the tissues of smokers than in nonsmokers, irrespective of diabetes. In view of previous reports implicating AGEs in a causal association with numerous pathologies, these findings have significant ramifications for understanding the etiopathology of diseases associated with smoking, the single greatest preventable cause of morbidity and mortality in the United States.

Comparison of p53 and DNA content abnormalities in adenocarcinoma of the oesophagus and gastric cardia

This study examined the association between 17p allelic loss, p53 gene mutation, p53 protein expression and DNA aneuploidy in a series of adenocarcinomas arising in the oesophagus and gastric cardia. 17p allelic loss was detected in 79% (15 of 19) of oesophageal and in 83% (29 of 35) of gastric adenocarcinomas. p53 mutations were detected in 70% (14 of 20) and 63% (26 of 41) of oesophageal and of gastric adenocarcinomas respectively. Both tumour types were associated with a predominance of base transitions at CpG dinucleotides. In five cases of oesophageal adenocarcinoma, the same mutation was detected both in tumour and in adjacent dysplastic Barrett's epithelium. Diffuse p53 protein expression was detected in 65% (13 of 20) and 59% (24 of 41) of oesophageal and of gastric tumours, respectively, and was associated with the presence of p53 missense mutation (Chi-squared, P < 0.0001). DNA aneuploidy was detected in 80% (16 of 20) of oesophageal and in 70% (28 of 40) of gastric tumours. No association was found between p53 or DNA content abnormalities and tumour stage or histological subtype. In conclusion, this study detected a similar pattern of p53 alterations in adenocarcinoma of the oesophagus and gastric cardia--molecular data consistent with the observation that these tumours demonstrate similar clinical and epidemiological features.

Barrett's oesophagus: microsatellite analysis provides evidence to support the proposed metaplasia-dysplasia-carcinoma sequence

The development of adenocarcinoma in Barrett's oesophagus is proposed to occur via a stepwise progression recognised histologically as a metaplasia-dysplasia-carcinoma sequence. In order to identify chromosomal loci involved in the malignant transformation of Barrett's epithelium and the development of oesophageal adenocarcinoma, microsatellite analysis was carried out on 17 cases of Barrett's-associated oesophageal adenocarcinoma. Samples of premalignant Barrett's epithelium adjacent to adenocarcinoma were obtained from seven of these cases. Allelic imbalance was detected in > 45% of informative cases of oesophageal adenocarcinoma on chromosome arms 3q (65%), 4q (71%), 5q (59%), 6q (59%), 9p (50%), 9q (47%), 12p (47%), 12q (65%), 17p (76%), and 18q (75%). Allelic imbalance at 4q, 17p, and 18q was significantly higher than the upper 95% confidence interval for background allelic imbalance. Allelic imbalance was detected at several loci in the premalignant epithelium from five of the seven cases studied. These loci included several chromosomal arms that had demonstrated high levels of allelic imbalance in oesophageal adenocarcinoma, namely, 4q (one case), 5q (two cases), 9 (three cases), 12q (five cases), 17p (four cases), and 18q (two cases). Novel microsatellite alleles were detected in both premalignant and malignant Barrett's epithelium. In three cases, dysplastic Barrett's epithelium and adjacent adenocarcinoma demonstrated the same pattern of novel microsatellite alleles at a number of loci. In conclusion, these data indicate chromosomal loci which may be specifically involved in the histological progression of Barrett's epithelium. The detection of shared novel microsatellite alleles in premalignant and malignant Barrett's epithelium is consistent with a process of clonal expansion underlying this progression.

Thrombin activates nuclear factor-kappaB and potentiates endothelial cell activation by TNF

Thrombin is the central bioregulatory enzyme in hemostasis and is generated in vascular beds in which inflammatory responses are ongoing. In this study, we examined the effect of thrombin, both alone and in combination with TNF, on gene expression in porcine aortic endothelial cells (EC). Thrombin (1-10 U/ml) induced increased mRNA levels of E-selectin, monocyte chemoattractant protein-1, IL-8, plasminogen activator inhibitor-1, and IkappaB-alpha. These effects were mimicked by a thrombin receptor-activating peptide; preincubation of thrombin with hirudin blocked the induction of mRNA, suggesting that the increased gene expression was due to thrombin-specific activity. Because these genes are known to contain nuclear-factor-kappaB (NF-kappaB)-binding elements in their promoter region, we next examined the ability of thrombin to activate this transcription factor. As detected by electrophoretic mobility shift assay, thrombin (10 U/ml) or thrombin receptor-activating peptide (100 microM) stimulated increased NF-kappaB-binding activity. Supershift analysis revealed that these complexes were comprised principally of the RelA (p65) and NF-kappaB1 (p50) Rel family members. Thrombin alone did not substantively increase protein levels of E-selectin despite the increase in E-selectin mRNA levels. However, thrombin (3-10 U/ml) stimulated a 10-fold enhancement in the ability of TNF (0.3-1.0 ng/ml) to induce E-selectin surface expression. Similar potentiation of TNF-induced NF-kappaB activity and E-selectin transcription by thrombin was observed in experiments utilizing luciferase reporter constructs expressed in bovine aortic EC. The ability of thrombin to potentiate TNF-induced EC activation thus provides an important mechanism by which products of the coagulation cascade may enhance cytokine-mediated inflammatory responses.

Thrombin activates nuclear factor-kappaB and potentiates endothelial cell activation by TNF

Thrombin is the central bioregulatory enzyme in hemostasis and is generated in vascular beds in which inflammatory responses are ongoing. In this study, we examined the effect of thrombin, both alone and in combination with TNF, on gene expression in porcine aortic endothelial cells (EC). Thrombin (1-10 U/ml) induced increased mRNA levels of E-selectin, monocyte chemoattractant protein-1, IL-8, plasminogen activator inhibitor-1, and IkappaB-alpha. These effects were mimicked by a thrombin receptor-activating peptide; preincubation of thrombin with hirudin blocked the induction of mRNA, suggesting that the increased gene expression was due to thrombin-specific activity. Because these genes are known to contain nuclear-factor-kappaB (NF-kappaB)-binding elements in their promoter region, we next examined the ability of thrombin to activate this transcription factor. As detected by electrophoretic mobility shift assay, thrombin (10 U/ml) or thrombin receptor-activating peptide (100 microM) stimulated increased NF-kappaB-binding activity. Supershift analysis revealed that these complexes were comprised principally of the RelA (p65) and NF-kappaB1 (p50) Rel family members. Thrombin alone did not substantively increase protein levels of E-selectin despite the increase in E-selectin mRNA levels. However, thrombin (3-10 U/ml) stimulated a 10-fold enhancement in the ability of TNF (0.3-1.0 ng/ml) to induce E-selectin surface expression. Similar potentiation of TNF-induced NF-kappaB activity and E-selectin transcription by thrombin was observed in experiments utilizing luciferase reporter constructs expressed in bovine aortic EC. The ability of thrombin to potentiate TNF-induced EC activation thus provides an important mechanism by which products of the coagulation cascade may enhance cytokine-mediated inflammatory responses.

Allelotype analysis of adenocarcinoma of the gastric cardia

To identify chromosomal loci involved in the development of proximal gastric adenocarcinoma, this study delineated the pattern of allelic imbalance in a series of 38 adenocarcinomas arising in the gastric cardia. A total of 137 microsatellite markers covering all autosomal arms, excluding acrocentric arms, were analysed. A mean of 35 out of a total of 39 chromosomal arms studied were informative for each patient. The tumour group demonstrated a high level of allelic imbalance, with an observed median fractional allelic imbalance of 0.47 for the 29 intestinal-type adenocarcinomas and 0.54 for the nine diffuse-type adenocarcinomas. Allelic imbalance was detected in >50% of informative cases in both histological subtypes on a number of chromosomal arms. In the intestinal subtype, these included, 3p (61%), 4q (71%), 5q (59%), 8p (60%), 9p (65%), 9q (83%), 12q (52%), 13q (52%), 17p (78%) and 18q (70%). A higher incidence of allelic imbalance was detected on chromosome 16q in tumours of the diffuse type relative to those of the intestinal type. A more detailed mapping on chromosomes 4q and 6q identified a number of cases with subchromosomal breakpoints. In conclusion, this analysis has indicated regions of the genome potentially involved in the development of proximal gastric carcinomas.

Expression and activation of protein kinase C isoforms in a human megakaryocytic cell line

Megakaryocytes undergo a unique differentiation program, becoming polyploid through repeated cycles of DNA synthesis without concomitant cell division. We have shown previously that phorbol 12-myristate 13-acetate (PMA) induces the Dami human megakaryocytic cell line to become polyploid and to express platelet-specific proteins, including von Willebrand factor (vWF) and glycoprotein Ib (GpIb). Phorbol esters are thought to regulate gene expression principally through the activation of protein kinase C (PKC), a family of structurally related kinases with potentially unique activation requirements and substrate specificities. A survey of PKC isoforms in Dami cells revealed that, by both Western and Northern analyses, PKC isoforms alpha, beta, delta, epsilon, eta, theta, and zeta were reproducibly detected. PKC-gamma was not detected. In order to define the role of individual PKC isoforms in megakaryocytic maturation, PMA and 2-deoxyphorbol 13-phenylacetate 20-acetate (dPPA), a putative selective activator of the PKC-beta 1 isotype, were compared for their effects on Dami cell maturation. Treatment with either dPPA or PMA caused Dami cells to cease proliferating, to become polyploid, and to express vWF. We also examined dPPA and PMA for their ability to activate and to downregulate expression of different PKC isoforms. Fifteen-minute treatment with PMA resulted in the translocation of PKC isoforms alpha, epsilon, and theta from the cytosolic to the membrane fraction; twenty-four hour treatment resulted in the downregulation of these isoforms. In contrast, dPPA was found to be a potent activator of PKC-epsilon alone and exhibited weaker effects on alpha and theta. These data suggest that PKC isoforms beta, delta, eta, and zeta, which appear not to be activated by either phorbol ester, are unlikely to be primarily involved in megakaryocytic maturation in response to these agents. The isoforms that are translocated by both phorbol esters-PKC isoforms alpha and theta, and particularly epsilon-are more likely to transduce the signals that stimulate Dami cell differentiation.

Widespread microsatellite instability occurs infrequently in adenocarcinoma of the gastric cardia

Heredity non-polyposis colorectal cancer (HNPCC) is associated with an increased predisposition to colorectal cancer and extra-colonic cancers of the gastro-intestinal, urological and female reproductive tracts. These tumours are characterised by an underlying defect in DNA mismatch repair and exhibit numerous replication errors throughout the genome (RER+ phenotype). HNPCC-associated gastric tumours, and a subset of sporadic, distally-located gastric tumours exhibit this RER+ phenotype. It is recognised that proximal and distal gastric tumours exhibit distinct epidemiological features. In this study we investigated the occurrence of microsatellite instability in a series of 38 primary gastric adenocarcinomas, arising in the proximal stomach. A total of 138 microsatellite markers, comprising mainly dinucleotide and tetranucleotide repeat units and covering all autosomal arms, excluding acrocentric arms, were analysed. One tumour demonstrated somatic microsatellite alterations at 62% (26 of 42) of loci tested. A further 32 tumours demonstrated levels of microsatellite instability ranging from 0.8% (1 of 28)-11.4% (15 of 132) of loci tested. Five tumours demonstrated no microsatellite alterations at any of the loci tested. These findings suggest that a high percentage of proximal gastric carcinomas exhibit a low level of microsatellite alterations at dinucleotide and tetranucleotide repeat loci. However, ubiquitous somatic alterations at these loci, characteristic of HNPCC-associated tumours, occur in a relatively small proportion of tumours.

Ubiquitous somatic alterations at microsatellite alleles occur infrequently in Barrett's-associated esophageal adenocarcinoma

Microsatellite alterations have been documented in a subset of sporadic tumors, including those of the colon, lung, bladder, stomach, and esophagus. This study documented the frequency of microsatellite alterations at 139 loci, comprising predominantly dinucleotide and tetranucleotide repeat units, in 17 cases of primary esophageal adenocarcinoma arising against a background of Barrett's metaplasia. Each tumor demonstrated alterations in at least one locus studied. Widespread microsatellite alterations, occurring at 45.3% (58 of 128) of loci tested, were detected in a single case. The remaining 16 tumors exhibited low levels of microsatellite instability, ranging from 0.8% (1 of 128) to 8.1% (10 of 123) of loci tested. The single case with ubiquitous somatic alterations showed no significant difference in the incidence of novel alleles at di- and tetranucleotide repeat loci. The 16 cases showing a low level of microsatellite alterations demonstrated a 3.3-fold higher incidence of novel alleles at tetranucleotide repeat loci compared to dinucleotide repeat loci. These data suggest that ubiquitous somatic alterations at microsatellite loci, considered a phenotypic expression of defective mismatch repair, occur infrequently in Barrett's-associated adenocarcinoma. However, the majority of these tumors demonstrate a low level of microsatellite alterations, perhaps reflecting the inherent instability of these markers.