The multi-disciplinary management of complex congenital and acquired tracheo-oesophageal fistulae

AIM OF THE STUDY

Complex tracheo-oesophageal fistulae (TOF) are rare congenital or acquired conditions in children. We discuss here a multidisciplinary (MDT) approach adopted over the past 5 years.

METHODS

We retrospectively collected data on all patients with recurrent or acquired TOF managed at a single institution. All cases were investigated with neck and thorax CT scan. Other investigations included flexible bronchoscopy and bronchogram (B&B), microlaryngobronchoscopy (MLB) and oesophagoscopy. All cases were subsequently discussed in an MDT meeting on an emergent basis if necessary.

MAIN RESULTS

14 patients were referred during this study period of which half had a congenital aetiology and the other half were acquired. The latter included button battery ingestions (5/7) and iatrogenic injuries during oesophageal atresia (OA) repair. Surgical repair was performed on cardiac bypass in 3/7 cases of recurrent congenital fistulae and all cases of acquired fistulae. Post-operatively, 9/14 (64%) patients suffered complications including anastomotic leak (1), bilateral vocal cord paresis (1), further recurrence (1), and mortality (1). Ten patients continue to receive surgical input encompassing tracheal/oesophageal stents and dilatations.

CONCLUSIONS

MDT approach to complex cases is becoming increasingly common across all specialties and is important in making decisions in these difficult cases. The benefits include shared experience of rare cases and full access to multidisciplinary expertise.

Validation of the Airway-Dyspnoea-Voice-Swallow (ADVS) scale and Patient-Reported Outcome Measure (PROM) as disease-specific instruments in paediatric laryngotracheal stenosis

OBJECTIVE

To validate the Airway-Dyspnoea-Voice-Swallow (ADVS) instrument as a disease-specific Patient-Reported Outcome Measure in paediatric laryngotracheal stenosis.

DESIGN

Prospective observational study.

SETTING

A quaternary referral centre for complex airway disease.

PARTICIPANTS

Forty-eight patients (30 males) with a mean age of 49 ± 49 months who underwent laryngotracheal surgery or microlaryngoscopy and bronchoscopy (MLB) following laryngotracheal surgery.

MAIN OUTCOME MEASURES

Airway-Dyspnoea-Voice-Swallow summary scale and Patient-Reported Outcome Measure (PROM), Paediatric Quality of Life (PedsQL) scale, Paediatric Voice Handicap Index (pVHI) and Lansky performance scale were administered to patients before and 6-8 weeks following airway examination/surgery.

RESULTS

Most patients (73%) had intubation-related subglottic stenosis, and 60% of patients had prior airway treatments. The majority of patients (77%) had more than one major chronic morbidity, and the commonest procedures were diagnostic MLB (49%), followed by airway dilation (29%). Cronbach-α value for the ADVS PROM was 0.71 overall and 0.85, 0.86 and 0.64 for the dyspnoea, voice and swallow domains, respectively. Rank correlations between Dyspnoea, Voice and Swallow summary scale and PROM scores were 0.83, 0.71 and 0.81, respectively (P < 0.0001). For those patients undergoing diagnostic MLB, pre- and post-examination scores were highly correlated (intraclass correlations >0.75). There was a significant rank correlation between ADVS PROM score and Lansky performance score (r = -0.68; P < 0.0001). There were significant correlations between PROM score and PedsQL (r = -0.57; P < 0.0001) and between voice domain of the PROM and pVHI (r = 0.78; P < 0.0001). There were strong correlations between Myer-Cotton stenosis severity and dyspnoea scale and PROM score (r = 0.68; P < 0.0001). There were significant differences in voice and swallow ADVS scales and PROM scores between patients with and without concomitant laryngeal/oesophageal pathology. Patient age and presence of high dyspnoea and swallowing PROM scores were independently associated with poorer quality of life and performance status.

CONCLUSIONS

These series of observations validate the ADVS instrument as a disease-specific outcome measure for paediatric laryngotracheal stenosis. Dyspnoea and swallowing dysfunction appear to have the greatest impact on quality of life. More widespread adoption of the ADVS instrument could help create a shared language for outcomes communication and benchmarking for children with this complex condition.

Full-mouth Tooth Extraction Lowers Systemic Inflammatory and Thrombotic Markers of Cardiovascular Risk

Prior studies of a link between periodontal and cardiovascular disease have been limited by being predominantly observational. We used a treatment intervention model to study the relationship between periodontitis and systemic inflammatory and thrombotic cardiovascular indicators of risk. We studied 67 adults with advanced periodontitis requiring full-mouth tooth extraction. Blood samples were obtained: (1) at initial presentation, immediately prior to treatment of presenting symptoms; (2) one to two weeks later, before all teeth were removed; and (3) 12 weeks after full-mouth tooth extraction. After full-mouth tooth extraction, there was a significant decrease in C-reactive protein, plasminogen activator inhibitor-1 and fibrinogen, and white cell and platelet counts. This study shows that elimination of advanced periodontitis by full-mouth tooth extraction reduces systemic inflammatory and thrombotic markers of cardiovascular risk. Analysis of the data supports the hypothesis that treatment of periodontal disease may lower cardiovascular risk, and provides a rationale for further randomized studies.

Neutrophil function and cardiopulmonary bypass in humans. The effects of glucose and non-glucose containing bypass pump priming fluids

Defective polymorphonuclear neutrophil function during cardiopulmonary bypass (CPB) has been implicated as a cause of postoperative infection following open-heart surgery. Neutrophil function is known to be impaired in poorly controlled diabetics with elevations of blood glucose concentrations of the order which occur frequently during CPB when glucose containing priming fluids are used. Neutrophil function, as measured by bactericidal assay, and neutrophil and whole blood luminol dependent chemiluminescence, was studied in two groups of 1 2 patients undergoing coronary artery bypass graft surgery. Patients received either a glucose or non-glucose containing bypass pump-priming fluid. Postoperatively neutrophil luminol-dependent chemiluminescence was significantly increased in both groups (glucose prime groups p < 0.01, non-glucose prime group p < 0.01). Whole blood chemiluminescence was increased significantly intra and postoperatively in the glucose prime group ( p < 0.02, p < 0.02 respectively) but the increase was not significant in the non-glucose prime group. Bactericidal activity remained unchanged during and after surgery in both groups (mean bactericidal index intraoperatively 96.4 glucose group, 96.2 non-glucose group; postoperatively 99.7 glucose group, 99.7 non-glucose group). These data suggest that glucose containing bypass priming fluids do not modulate significantly the function of circulating neutrophils after CPB. Neutrophil function was not decreased after surgery, and other factors may be responsible for the reported higher incidence of bacterial infection after CPB.

The effect on intermediary metabolism of open-heart surgery with deep hypothermia and circulatory arrest in infants of less than 10 kilograms body weight. A preliminary study

The effects of hypothermic open-heart surgery with circulatory arrest upon intermediary metabolism and endocrine function in small children are still poorly understood. This report presents data obtained in a preliminary study in which seven children of <10 Kg body weight were investigated during and after such procedures. Frequent blood samples were taken from one day preoperatively to seven days postoperatively for estimation of hormone concentrations (insulin, growth hormone, glucagon, cortisol), and intermediary metabolites (glucose, lactate, pyruvate, alanine, glycerol, and 3- hydroxybutyrate).

Marked hyperglycaemia (34·8 ±3·3 mmol/L) was observed during cardiopulmonary bypass probably as a result of the glucose content of the pump prime. Moderate hyperglycaemia persisted for at least seven days postoperatively. A significant increase in lactate concentrations (p < 0·02) was observed during circulatory arrest and peak concentrations of 6·77 +0.87 mmol/L were measured at the end of the operation. Very high blood lactate concentrations were observed at the end of cardiopulmonary bypass in two patients who subsequently died. Peak insulin concentrations (20·7 ± 5·2 mU/L) were lower than those (30-40 mU/L) reported in adults undergoing similar procedures. Glucagon concentrations were significantly elevated during bypass ( p<0·05) to approximately twice the levels reported in adults. Unlike the other hormones, growth hormone concentrations revealed remarkably uniform change, similar to those reported in 'high responding' adults with peak values of 124 ± 26 mU/L, observed during cardiopulmonary bypass. Cortisol concentrations showed no significant changes throughout the study.

Thus, the response of small infants to these procedures differed both qualitatively and quantitatively from that reported in adults. The results suggest that the nature of the prime fluid may be of major importance in the metabolic consequences of such surgery and that glucose and lactate may be better avoided in the pump prime.

Paediatric CPB: Bypass in a High Risk Group

Children and particularly neonates present unique challenges during CPB. Patient age, size, underlying anatomy and surgical strategy influence the perfusion techniques and the construction of the CPB circuit. The normal changes in physiology in the first weeks of life impact upon surgical technique and outcome of repair.

Limited surgical access necessitates alternative cannulation strategies. Deep hypothermia, low flow CPB and circulatory arrest are frequently used. An understanding of the related pathophysiology is therefore required to make the correct choices and to optimise patient outcome.

Decreased cost and improved feeding tolerance in VLBW infants fed an exclusive human milk diet

OBJECTIVE

Human milk is the best form of nutrition for preterm infants and has been associated with a lower incidence of necrotizing enterocolitis (NEC). Infants that develop NEC have a higher incidence of feeding intolerance and longer hospitalizations. The combination of a donor milk bank and donor milk-derived fortifier has changed feeding practices in neonatal intensive care units (NICU). The purpose of this study is to assess the benefits and cost of an exclusive human milk (EHM) diet in very low birth weight (VLBW) infants in a community level III NICU.

STUDY DESIGN

This is a retrospective study including preterm infants ⩽28 weeks and/or VLBW (⩽1500 g) who were enrolled from March 2009 until March 2014. Infants were grouped as follows: group H (entirely human milk based, born March 2012 to 2014), group B (bovine-based fortifier and maternal milk, born March 2009 to 2012), group M (mixed combination of maternal milk, bovine-based fortifier and formula, born March 2009 to 2012) and group F (formula fed infants, born March 2009 to 2012). Baseline characteristics among the four groups were similar.

RESULT

The study included 293 infants between gestational ages 23 to 34 weeks and birth weights between 490 and 1700 g. Feeding intolerance occurred less often (P<0.0001), number of days to full feeds was lower (P<0.001), incidence of NEC was lower (P<0.011), and total hospitalization costs were lower by up to $106,968 per infant (P<0.004) in those fed an EHM diet compared with the other groups. Average weight gain per day was similar among the four groups (18.5 to 20.6 g per day).

CONCLUSIONS

Implementing an EHM diet in our VLBW infants has led to a significant decrease in the incidence of NEC. Other benefits of this diet include: decreased feeding intolerance, shorter time to full feeds, shorter length of stay, and lower hospital and physician charges for extremely premature and VLBW infants.

Characterization of Human CD8(+)TCR(-) Facilitating Cells In Vitro and In Vivo in a NOD/SCID/IL2rγ(null) Mouse Model

CD8(+)/TCR(-) facilitating cells (FCs) in mouse bone marrow (BM) significantly enhance engraftment of hematopoietic stem/progenitor cells (HSPCs). Human FC phenotype and mechanism of action remain to be defined. We report, for the first time, the phenotypic characterization of human FCs and correlation of phenotype with function. Approximately half of human FCs are CD8(+)/TCR(-)/CD56 negative (CD56(neg)); the remainder are CD8(+)/TCR(-)/CD56 bright (CD56(bright)). The CD56(neg) FC subpopulation significantly promotes homing of HSPCs to BM in nonobese diabetic/severe combined immunodeficiency/IL-2 receptor γ-chain knockout mouse recipients and enhances hematopoietic colony formation in vitro. The CD56(neg) FC subpopulation promotes rapid reconstitution of donor HSPCs without graft-versus-host disease (GVHD); recipients of CD56(bright) FCs plus HSPCs exhibit low donor chimerism early after transplantation, but the level of chimerism significantly increases with time. Recipients of HSPCs plus CD56(neg) or CD56(bright) FCs showed durable donor chimerism at significantly higher levels in BM. The majority of both FC subpopulations express CXCR4. Coculture of CD56(bright) FCs with HSPCs upregulates cathelicidin and β-defensin 2, factors that prime responsiveness of HSPCs to stromal cell-derived factor 1. Both FC subpopulations significantly upregulated mRNA expression of the HSPC growth factors and Flt3 ligand. These results indicate that human FCs exert a direct effect on HSPCs to enhance engraftment. Human FCs offer a potential regulatory cell-based therapy for enhancement of engraftment and prevention of GVHD.

Tissue-Engineered Tracheal Replacement in a Child: A 4-Year Follow-Up Study

In 2010, a tissue-engineered trachea was transplanted into a 10-year-old child using a decellularized deceased donor trachea repopulated with the recipient's respiratory epithelium and mesenchymal stromal cells. We report the child's clinical progress, tracheal epithelialization and costs over the 4 years. A chronology of events was derived from clinical notes and costs determined using reference costs per procedure. Serial tracheoscopy images, lung function tests and anti-HLA blood samples were compared. Epithelial morphology and T cell, Ki67 and cleaved caspase 3 activity were examined. Computational fluid dynamic simulations determined flow, velocity and airway pressure drops. After the first year following transplantation, the number of interventions fell and the child is currently clinically well and continues in education. Endoscopy demonstrated a complete mucosal lining at 15 months, despite retention of a stent. Histocytology indicates a differentiated respiratory layer and no abnormal immune activity. Computational fluid dynamic analysis demonstrated increased velocity and pressure drops around a distal tracheal narrowing. Cross-sectional area analysis showed restriction of growth within an area of in-stent stenosis. This report demonstrates the long-term viability of a decellularized tissue-engineered trachea within a child. Further research is needed to develop bioengineered pediatric tracheal replacements with lower morbidity, better biomechanics and lower costs.

Tissue-Engineered Tracheal Replacement in a Child: A 4-Year Follow-Up Study

In 2010, a tissue-engineered trachea was transplanted into a 10-year-old child using a decellularized deceased donor trachea repopulated with the recipient's respiratory epithelium and mesenchymal stromal cells. We report the child's clinical progress, tracheal epithelialization and costs over the 4 years. A chronology of events was derived from clinical notes and costs determined using reference costs per procedure. Serial tracheoscopy images, lung function tests and anti-HLA blood samples were compared. Epithelial morphology and T cell, Ki67 and cleaved caspase 3 activity were examined. Computational fluid dynamic simulations determined flow, velocity and airway pressure drops. After the first year following transplantation, the number of interventions fell and the child is currently clinically well and continues in education. Endoscopy demonstrated a complete mucosal lining at 15 months, despite retention of a stent. Histocytology indicates a differentiated respiratory layer and no abnormal immune activity. Computational fluid dynamic analysis demonstrated increased velocity and pressure drops around a distal tracheal narrowing. Cross-sectional area analysis showed restriction of growth within an area of in-stent stenosis. This report demonstrates the long-term viability of a decellularized tissue-engineered trachea within a child. Further research is needed to develop bioengineered pediatric tracheal replacements with lower morbidity, better biomechanics and lower costs.

Bronchomegaly as a complication of fetal endoscopic tracheal occlusion. A caution and a possible solution

Fetal medicine is developing rapidly and aims to improve the outcome for fetuses with congenital anomalies. Fetal endoscopic tracheal occlusion (FETO) has been developed for fetuses with congenital diaphragmatic hernia to counterbalance the compression of the lung by the abdominal viscera, preserving the pulmonary maturation. Because the perinatal morbidity and mortality of patients treated with FETO have decreased, new complications are emerging in the older survivors. Tracheomegaly has been reported to be a late complication of FETO, sometimes requiring tracheostomy. We report a case of bronchial dilatation after FETO and suggest an alternative surgical treatment.

Wilms' tumour with persistent intravascular extension: a review of the surgical aspects of management

AIM

To review the surgical management of Wilms' tumour with persistent intravascular (vena caval +/- atrial) tumour extension.

PATIENTS AND METHODS

Data were collected regarding operative details, tumour and 'thrombus' histology, and long-term outcome for patients with Wilms' tumour with cavo-artial extension.

RESULT

From 1988 to 2004, 13 patients underwent treatment for Wilms' tumour with persistent intravascular extension. Preoperative chemotherapy was administered in 11/13 patients and postoperative radiotherapy in eight patients. Intravascular involvement was upto IVC (5), and right atrium (8) patients. Techniques employed for excision of intra-vascular component were: local cavotomy (3), extensive infra-diaphragmatic cavotomy without cardiopulmonary bypass (CPB) (1), and excision of cavo-atrial tumour with CPB (+/- hypothermia and cardiac arrest) (9). Mean time on CPB was 90 min. Caval repair was accomplished by primary repair (6) and pericardial graft in (7) patients. There were no intraoperative deaths and few major complications. Tumour thrombus contained malignant cells in 10/13 cases. Mean follow up has been for 55.4 months. To date, seven patients remain disease-free (one lost to follow up), disease recurred in five patients, three of whom have died. There were no symptoms related to the graft.

CONCLUSIONS

Surgery for Wilms' tumour with persistent intravascular extension despite chemotherapy is technically challenging. CPB +/- hypothermia and cardiac arrest and extensive caval repair with a graft is safe and reliable in the long term.

Surveillance bronchoscopy in children during the first year after lung transplantation: Is it worth it?

BACKGROUND

Since January 2002, routine surveillance bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy has been performed in all paediatric recipients of lung and heart-lung transplants at the Great Ormond Street Hospital for Children, London, UK, using a newly revised treatment protocol.

AIMS

To report the prevalence of rejection and bacterial, viral or fungal pathogens in asymptomatic children and compare this with the prevalence in children with symptoms.

PARTICIPANTS

The study population included all paediatric patients undergoing single lung transplantation (SLTx), double lung transplantation (DLTx) or heart-lung transplantation between January 2002 and December 2005.

METHODS

Surveillance bronchoscopies were performed at 1 week, and 1, 3, 6 and 12 months after transplant. Bronchoscopies were classified according to whether subjects had symptoms, defined as the presence of cough, sputum production, dyspnoea, malaise, decrease in lung function or chest radiograph changes.

RESULTS

Results of biopsies and BAL were collected, and procedural complications recorded. 23 lung-transplant operations were performed, 12 DLTx, 10 heart-lung transplants and 1 SLTx (15 female patients). The median (range) age of patients was 14.0 (4.9-17.3) years. 17 patients had cystic fibrosis. 95 surveillance bronchoscopies were performed. Rejection (> or =A2) was diagnosed in 4% of biopsies of asymptomatic recipients, and in 12% of biopsies of recipients with symptoms. Potential pathogens were detected in 29% of asymptomatic patients and in 69% of patients with symptoms. The overall diagnostic yield was 35% for asymptomatic children, and 85% for children with symptoms (p < 0.001). The complication rate for bronchoscopies was 3.2%.

CONCLUSIONS

Many children have silent rejection or subclinical infection in the first year after lung transplantation. Routine surveillance bronchoscopy allows detection and targeted treatment of these complications.

Heart and heart-lung transplantation for idiopathic restrictive cardiomyopathy in children

OBJECTIVE

To review the outcome of cardiac transplantation for restrictive cardiomyopathy (RCM) in children and to assess the ability of new strategies to modulate the effects of high pulmonary vascular resistance.

DESIGN

Retrospective case note analysis of all patients receiving a transplant for RCM.

PATIENTS

18 children with RCM referred for transplantation assessment to Great Ormond Street Hospital, London.

RESULTS

Eight boys and 10 girls were referred for assessment. Median age at presentation was 5.0 (mean (SD) 6.1 (4.0)) years. Fourteen orthotopic and two heterotopic transplantations were performed and two patients were referred for heart-lung transplantation. Mean duration from diagnosis to transplantation was 3.3 (3.0) years. Three patients with haemodynamic decompensation before transplantation had increased morbidity in the postoperative period. No patients died while awaiting a transplant. Three patients died in the first year after transplantation, one within 30 days. Five patients received pre-transplantation prostacyclin for a mean duration of 57 (18) days. Transpulmonary gradient was reduced in four of the patients. Mean transpulmonary gradient was 27 (9.8) mm Hg before and 17 (6.7) mm Hg after treatment with prostacyclin (p < 0.05).

CONCLUSION

Most children with RCM require transplantation within four years of diagnosis. Referral for transplantation assessment should precede haemodynamic decompensation. Increase of pulmonary vascular resistance is a variable problem but can be modulated with pre-transplantation prostacyclin. With these strategies, orthotopic transplantation is possible in the majority of cases.

Computed tomography versus bronchography in the diagnosis and management of tracheobronchomalacia in ventilator dependent infants

AIM

To assess the relative accuracy of dynamic spiral computed tomography (CT) compared with tracheobronchography, in a population of ventilator dependent infants with suspected tracheobroncho-malacia (TBM).

SETTING

Paediatric intensive care unit in a tertiary teaching hospital.

PATIENTS AND METHODS

Infants referred for investigation and management of ventilator dependence and suspected of having TBM were recruited into the study. Tracheobronchography and CT were performed during the same admission by different investigators who were blinded to the results of the other investigation. The study was approved by the hospital research ethics committee, and signed parental consent was obtained.

RESULTS

Sixteen infants were recruited into the study. Fifteen had been born prematurely, and five had cardiovascular malformations. In 10 patients there was good or partial correlation between the two investigations, but in six patients there was poor or no correlation. Bronchography consistently showed more dynamic abnormalities, although CT picked up an unsuspected double aortic arch. Radiation doses were 0.27-2.47 mSv with bronchography and 0.86-10.67 mSv with CT.

CONCLUSIONS

Bronchography was a better investigation for diagnosing TBM and in determining opening pressures. Spiral CT is unreliable in the assessment of TBM in ventilator dependent infants. In addition, radiation doses were considerably higher with CT.

Massive cardiac chondroma presenting with heart failure and superior vena cava obstruction in a teenage boy

Histologically benign soft-tissue chondromas have been reported at many anatomical sites but are an uncommon cause of soft tissue mass lesions in childhood, accounting for less than 1% of cases. The most frequent sites for extraosseous soft-tissue chondromas are the hands and feet. For the extremely rare visceral chondromas, the site can be lung, where they may represent a component of Carney's syndrome of extra-adrenal paraganglioma, pulmonary chondroma, and epithelioid leiomyosarcoma of the gastrointestinal tract. Primary cardiac chondromas are exceptionally rare in patients of any age although cardiac chondrosarcoma, both primary and metastatic, is well reported. We present a case of a teenage boy with a fatal cardiac chondroma

p53 gene transfer does not enhance E2F-1-mediated apoptosis in human colon cancer cells

E2F-1 and p53 are sequence specific transcription factors that are intimately involved in the regulation of the cell cycle. In addition to their role in cell cycle control, both E2F-1 and p53 have been identified as tumor suppressors and mediators of apoptosis. We have shown previously that adenoviral-mediated E2F-1 overexpression induces efficient apoptosis in colon adenocarcinoma cells. Previous reports have suggested that E2F-1 and p53 cooperate to mediate apoptosis and therefore, in this study, we examined the efficacy of combination gene therapy using adenovirus vectors expressing E2F-1 and p53 in human colon adenocarcinoma cell lines, HT-29 and SW620 (both mutant p53). Cells were treated by mock infection or infection with adenoviral vectors expressing b-galactosidase (LacZ), E2F-1, p53 or a combination of E2F-1 and p53. IC25 concentrations of each virus were estimated and used for each treatment in order to detect any synergistic or cooperative effects on tumor cell death in the combination therapy. By 5 days post infection, E2F-1-overexpressing cells exhibited growth inhibition and approximately 40-50% cell death in both cell lines. Co-expression of p53 with E2F-1 abrogated E2F-1-mediated growth inhibition and cell death. Cell cycle analysis revealed that overexpression of E2F-1 resulted in an accumulation of cells in G2/M phase, while overexpression of p53 resulted in a G1 phase accumulation. However, co-expression of E2F-1 and p53 counteracted each other as fewer cells accumulated in G1 and G2/M when compared to either p53 or E2F-1 alone. Furthermore, co-expression of p53 with E2F-1 resulted in decreased levels of E2F-1 protein expression. Mechanistically, upregulation of the CDK inhibitory protein, p21(WAF1/CIP1), was demonstrated in HT-29 cells following overexpression of either E2F-1, p53 or the combination E2F-1/p53 therapy. However, in SW620 cells, only the cells infected with Ad-p53 alone or in combination resulted in upregulation of p21(WAF1/CIP1). These results suggest that p53 and p21(WAF1/CIP1) may cooperate to inhibit the expression and activity of E2F-1. In conclusion, combination adenoviral vector-mediated E2F-1 and p53 gene transfer was not therapeutically advantageous in this in vitro model of human colon adenocarcinoma.

E2F-1 up-regulates c-Myc and p14(ARF) and induces apoptosis in colon cancer cells

Although overexpression of E2F-1 can induce apoptosis in a variety of tumor cell lines, the mechanisms by which E2F-1 induces apoptosis remain ambiguous. In this study, we examine the ability of E2F-1 to induce apoptosis in colon cancer and the molecular mechanisms underlying E2F-1-mediated apoptosis. HT-29 and SW-620 colon adenocarcinoma cells (both mutant p53) were treated by mock infection or adenoviral vectors Ad5CMV (empty vector), Ad5CMVLacZ (beta-galactosidase), and Ad5CMVE2F-1 (E2F-1) at multiplicity of infection of 100. Western blot analysis confirmed marked overexpression of E2F-1 in both cell lines. By 5 days after infection, E2F-1 overexpression resulted in >25-fold reduction in cell growth and >90% loss of cell viability in both cell lines. Cell cycle analysis of Ad-E2F-1-infected cells revealed an increase in G(2)/M and sub-G(1) populations. By in situ terminal deoxynucleotidyl transferase (Tdt)-mediated nick end labeling analysis, evidence of apoptosis was observed including internucleosomal DNA fragmentation and the formation of apoptotic bodies. In addition, caspase-3 and poly(ADP-ribose) polymerase apoptotic fragments were detected by 48 h after treatment with Ad-E2F-1. Of mechanistic importance, overexpression of E2F-1 caused a G(2)/M arrest followed by increased levels of c-Myc and p14(ARF) proteins. Additionally, expression of the antiapoptotic Bcl-2 family member Mcl-1 was down-regulated in E2F-1-overexpressing cells. In conclusion, E2F-1 overexpression initiates apoptosis and suppresses growth in HT-29 and SW620 colon adenocarcinoma cells. Overexpression of E2F-1 triggers apoptosis and is associated with up-regulation of c-Myc and p14(ARF) proteins and down-regulation of Mcl-1. Therefore, E2F-1 is a potentially active gene therapy agent for the treatment of colon cancer.

Normothermic versus hypothermic cardiopulmonary bypass during repair of congenital heart disease

OBJECTIVE

To compare normothermic cardiopulmonary bypass (CPB) versus hypothermic CPB in pediatric patients undergoing repair of congenital heart disease with focus on biochemical markers for brain damage.

DESIGN

Prospective randomized interventional study.

SETTING

Postgraduate teaching hospital.

PARTICIPANTS

Twenty patients undergoing repair of congenital heart disease.

INTERVENTIONS

Patients were randomized to normothermic (36 degrees C) versus hypothermic (25 degrees C) CPB. Serum levels of neuron-specific enolase (NSE) and S-100beta protein were measured in all patients before surgery, immediately after CPB, and 12 and 24 hours after surgery. Blood loss and time for extubation of the trachea were recorded.

MEASUREMENTS AND MAIN RESULTS

Before operation, the S-100beta protein and NSE levels were similar in the 2 groups. The S-100beta protein serum level increased significantly after CPB in both groups, whereas no change was found in the NSE level. There was no difference in the change of NSE and S-100beta protein levels between normothermic and hypothermic CPB. Blood loss was significantly less after hypothermic CPB (25 mL/kg/24 h v 42 mL/kg/24 h). Time for extubation was similar.

CONCLUSION

No difference was found in the release of brain-specific proteins between normothermic and hypothermic CPB, but blood loss was higher after normothermic CPB.

Effect of delayed sternal closure after cardiac surgery on respiratory function in ventilated infants

OBJECTIVE

Studies examining the effect of sternal closure on respiratory function have not been published, and currently there is little evidence to guide ventilation management immediately after closure. The aim of this study was to establish the impact of delayed sternal closure on expired tidal volume, respiratory system compliance, and CO2 elimination immediately after the procedure in infants who had undergone open heart surgery.

DESIGN

Prospective study of respiratory function before and after delayed sternal closure.

SETTING

Cardiac intensive care unit, Great Ormond Street Hospital, London.

PATIENTS

Seventeen infants (median age, 2 wks) with open median sternotomy incisions after cardiac surgery. Data were collected between August 1998 and March 2000.

INTERVENTIONS

Respiratory function was measured continuously for 30 mins before and after delayed sternal closure in paralyzed ventilated infants.

MEASUREMENTS AND RESULTS

Four babies were excluded from the study because they required either immediate increase in ventilation after delayed sternal closure (n = 3) or removal of pericardial blood collection (n = 1). In the remaining 13 infants, expired tidal volume and CO2 elimination decreased significantly (p < .005) by a mean of 17% and 29%, respectively, after sternal closure. In five of the remaining 13 patients, the magnitude of tracheal tube leak increased by > or = 10% after delayed sternal closure, thereby invalidating recorded changes in respiratory system compliance. Of the eight infants in whom there was a minimal change in leak, respiratory system compliance decreased significantly (p < .05) by a mean of 19%.

CONCLUSIONS

This study supports the hypothesis that respiratory function may be compromised after delayed sternal closure and that ventilatory support should be increased to counteract the anticipated decrease in tidal volume. Extra vigilance should be applied in monitoring blood gases after delayed sternal closure to assess clinical responses to sternal closure or changes in ventilatory support. Accurate assessment of change in respiratory system compliance after any therapeutic intervention may be precluded by changes in tracheal tube leak during the procedure.

Traumatic disruption of the ascending aorta in a child after heart transplant

We report a traumatic disruption of the ascending aorta in an 8-year-old boy who had undergone orthotopic cardiac transplant at 6.5 years of age for congenital heart block and dilated cardiomyopathy. At presentation his aortic injury was not immediately recognized, but persistence in identifying and confirming a suspicious aortic rupture was lifesaving.

A case for anatomic correction in atrioventricular discordance? Effects of surgery on tricuspid valve function

OBJECTIVE

To assess tricuspid valve function in atrioventricular discordance after palliative procedures (pulmonary artery banding and Blalock-Taussig shunt) and corrective procedures (anatomic and physiologic repair).

METHODS

Tricuspid valve dysfunction was assessed by transthoracic echocardiography and graded as no regurgitation (0), mild (1), moderate (2), and severe (3) before and after palliative and corrective procedures performed in 97 patients with atrioventricular discordance between 1988 and 1999. Thirty-two percent had an isolated ventricular septal defect, 43% had a ventricular septal defect and pulmonary stenosis, and 16% had pulmonary stenosis. Twenty-six patients underwent pulmonary artery banding and 28 had a Blalock-Taussig shunt. Seventy patients underwent physiologic and 19 underwent anatomic repair. Six patients underwent one-ventricle repair.

RESULTS

After pulmonary artery banding, the tricuspid regurgitation score decreased from 1.7 +/- 0.8 to 0.9 +/- 0.6 (P <.001). In patients who underwent a Blalock-Taussig shunt, the tricuspid regurgitation score increased from 0.7 +/- 0.5 preoperatively to 1.4 +/- 0.6 postoperatively (P <.001). After physiologic repair, there was no significant change in the tricuspid regurgitation score; however, 7 patients required additional repair or replacement. The regurgitation score was significantly reduced from 1.5 +/- 0.8 to 0.4 +/- 0.5 (P <.001) after anatomic repair. The operative mortality in patients who underwent physiologic repair was 7% as compared with 0% in the anatomic repair group (P =.59). The median follow-up was 3.2 years.

CONCLUSIONS

Right ventricular volume loading (shunt) worsens tricuspid regurgitation, whereas volume reduction (banding) or left-to-right septal shift (anatomic repair) has beneficial effects. We have not observed a significant change in the tricuspid regurgitation score after physiologic repair. Anatomic repair can be performed in selected patients with atrioventricular discordance and provides superior functional results.

Additive effect of adenovirus-mediated E2F-1 gene transfer and topoisomerase II inhibitors on apoptosis in human osteosarcoma cells

Recently, it has been demonstrated that Etoposide, a topoisomerase II inhibitor, can induce apoptosis in MDM2-overexpressing tumor cells by inhibition of MDM2 synthesis. We have previously shown that E2F-1 overexpression induces apoptosis of MDM2-overexpressing sarcoma cells, which is related to the inhibition of MDM2 expression. Therefore, the present study was designed to investigate the in vitro and in vivo effect of combined treatment of adenovirus-mediated E2F-1 and topoisomerase II inhibitors on the growth inhibition and apoptosis in human sarcoma cells. Two human sarcoma cell lines, OsACL and U2OS, were treated with topoisomerase II inhibitors (Etoposide and Adriamycin), alone or in combination with adenoviral vectors expressing beta-galactosidase (Ad-LacZ) or E2F-1 (Ad-E2F-1). E2F-1 expression was confirmed by Western blot analysis. Ad-E2F-1 gene transfer at a low dose (multiplicity of infection, 2) markedly increased the sensitivity of human sarcoma cells to topoisomerase II inhibitor treatment. This cooperative effect of E2F-1 and topoisomerase II inhibitors was less marked in SAOS-2 cells (p53 and pRb null). Topoisomerase II inhibitors also cooperated with E2F-1 overexpression to enhance tumor cell killing in an in vivo model using xenografts in nude mice. When combined with Adriamycin or Etoposide, E2F-1 adenovirus therapy resulted in approximately 95% and 85% decrease in tumor size, respectively, compared to controls (P<.05). These results suggest a new chemosensitization strategy that is effective in MDM2-overexpressing tumors and may have clinical utility.

Avascular necrosis of the talus after McKay clubfoot release for idiopathic congenital clubfoot

Avascular necrosis of the talus is a serious potential complication of clubfoot surgery. In the few cases described in the literature, the necrosis has involved the entire talus and resulted in progressive fragmentation and collapse. Serial postoperative radiographs of 96 idiopathic clubfeet in 70 patients are reviewed here to determine the incidence of avascular necrosis after McKay soft tissue release. Based on criteria in the literature for making the diagnosis, no cases of avascular necrosis were seen. Growth lines were observed in the cuboids and calcanei of all the feet during the follow-up period. Eight feet failed to develop growth lines in the talus during follow-up. Five of these feet showed flattening of the dome of the talus and three hypoplasia of the talar head and neck at the most recent follow-up. Absence of normal growth lines in the talus after operation seems to predict talar abnormalities.

Current management and outcome of tracheobronchial malacia and stenosis presenting to the paediatric intensive care unit

OBJECTIVE

To identify factors associated with mortality and prolonged ventilatory requirements in patients admitted to our paediatric intensive care unit (PICU) with tracheobronchial malacia and stenosis diagnosed by dynamic contrast bronchograms.

DESIGN

Retrospective review.

SETTING

Tertiary paediatric intensive care unit.

PATIENTS

Forty-eight cases admitted to our PICU over a 5-year period in whom a diagnosis of tracheobronchial malacia or stenosis was made by dynamic contrast bronchography (1994-1999).

INTERVENTIONS

Conservative management, tracheostomy and long-term ventilation, surgical correction, internal or external airway stenting.

MEASUREMENTS AND RESULTS

Recording of clinical details, length of invasive ventilation and appearance at contrast bronchography. Five groups of patients were defined: isolated primary airway pathology (n = 7), ex-premature infants (n = 11), vascular rings (n = 9), complex cardiac and/or syndromic pathology (n = 17) and tracheo-oesophageal fistulae (n = 4). The overall mortality was 29%. Median length of invasive ventilation in survivors was 38 days and in patients who died 45. Mortality was highest in the patients with complex cardiac and/or syndromic pathology (p = 0.039 Cox regression analysis) but was not related to any other factor. Patients with stenosis required a significantly longer period of ventilatory support (median length of ventilation 59 days) than patients with malacia (39 days).

CONCLUSIONS

Length of ventilation and bronchographic diagnosis did not predict survival. The only factor found to contribute significantly to mortality was the presence of complex cardiac and/or syndromic pathology. However, patients with stenosis required longer ventilatory support than patients with malacia.

The effect of prelung transplant clinical status on post-transplant survival of children with cystic fibrosis

The aim of this study was to determine whether transplanting paediatric cystic fibrosis (CF) patients later in the course of their disease was detrimental to their post-transplant survival. Data was collected from 51 children with CF undergoing lung or heart-lung transplantation May 1988-March 1999. The following risk factors were tested by Cox proportional hazards modelling: age at transplant; sex; donor/recipient sex mismatch; donor/recipient cytomegalovirus (CMV) mismatch; cold and warm graft ischaemic times; and donor age. Pretransplant forced expiratory volume in one second (FEV1), minimum oxygen saturation obtained during 12 min walk (Sa,O2min), and a survival probability score (SP) calculated from FEV1, age adjusted resting heart rate, age, sex, blood haemoglobin (Hb), and serum albumin were then added to the model. None of the risk factors were significantly correlated with death during the study period. No evidence that clinical status prior to transplant has any effect upon the post-transplant survival of children with cystic fibrosis was found.

The role of airway stents in the management of pediatric tracheal, carinal, and bronchial disease

OBJECTIVE

A variety of stents are available to aid in the management of complex tracheal, carinal and bronchial stenoses. We reviewed our multi-institutional experience with airway stents in children.

METHODS

Thirty-three children (age, 13 days-18 years) from four institutions have had a total of 40 stents placed to aid in the management of complex airway stenoses. Three stent types were utilized: 29 silastic stents, five expandable metal stents and six customized carinal stents (four patients had two stents and one patient had four stents). Thirty children had tracheal stents, six children had bronchial stents, and two infants had carinal stents (three children had stenting of more than one area and two had stenting of all three locations). Twenty-eight patients (age, 5 months-18 years; mean, 8.06 years; SEM, 1.13 years) had stents placed after a variety of airway reconstructive procedures. Four underwent stenting in a non-operative setting and one as preoperative stabilization.

RESULTS

Twenty-seven patients survived. One patient died early due to bleeding. Five patients died late: two due to bleeding, one from mediastinitis, and two patients with functional airways died late from unrelated problems. Complications are related to stent type and location. Carinal stents can migrate; several techniques are available to help manage this problem. Wire stents are essentially non-removable requiring periodic dilation. Silastic stents stimulate granulation tissue formation requiring periodic bronchoscopic removal.

CONCLUSION

Tracheal stenting can aid in the management of pediatric airway problems. Complications are common, but can be managed with appropriate intervention.

Presentation of the International Nomenclature for Congenital Heart Surgery. The long way from nomenclature to collection of validated data at the EACTS

An International Nomenclature for Congenital Heart Surgery was officially adopted at the Annual Meeting of the EACTS in Glasgow, UK on September 6, 1999. This nomenclature was achieved following 1 year's work of the International Nomenclature and Data Base Committee for Congenital Heart Surgery of the Society of Thoracic Surgeons. This international group included members from the STS, AATS, AHA and EACTS and associated surgeons and cardiologists from United States, Canada, Australia and Europe. The Nomenclature includes a minimal data set of 21 items and lists of 150 diagnoses, 200 procedures, 32 complications and 28 extra cardiac anomalies and preoperative risk factors. It will serve as a basis for the Pediatric European Cardiac Surgical Registry (http://www.pediatric. ecsur.org). The outcome of such an International Nomenclature represents an important event for the medical community in charge of treating patients with congenital heart diseases. It will allow scientific exchanges on an international scale and promote multicenter evaluation of congenital heart surgery. Nevertheless, this Nomenclature is only the first step. Further collection of validated data at the Pediatric ECSUR Data Base requires ethical belief, time consumption and financial resources. Comparison of results, according to pathologies, across centers and countries will help define, in the future, official European standards of Quality of Care available for health care organizations, public scrutiny and governmental agencies.

Adenovirus-mediated E2F-1 gene transfer induces an apoptotic response in human gastric carcinoma cells that is enhanced by cyclin dependent kinase inhibitors

E2F -1 is a transcription factor that regulates cell cycle progression into S-phase. Deregulation of E2F-1 activity has been associated with cellular commitment to apoptosis. Also critical in the regulation of S-phase are the actions of the cyclin dependent kinases, Cdk2 and cdc2. Inhibition of these cyclin dependent kinases has been similarly associated with disrupting orderly S-phase progression and causing subsequent apoptosis in certain cancer cells. In this study, we examine the ability of adenovirus-mediated E2F-1 overexpression to induce apoptosis in human gastric carcinoma cells. Furthermore, we investigate the effect of the cyclin dependent kinase inhibitors, olomoucine and roscovitine, on E2F-1-mediated apoptosis in human gastric carcinoma cells. AGS and SNU-1 gastric adenocarcinoma cells were infected with adenoviral vectors expressing E2F-1 (Ad5CMVE2F-1) or control viruses expressing beta-galactosidase (Ad5CMVLacZ) or lacking a transgene (Ad5). Gastric adenocarcinoma cells were then independently treated with roscovitine or olomoucine. Finally, gastric adenocarcinoma cells were infected with the various adenoviral vectors in combination with roscovitine or olomoucine. E2F-1 overexpression resulted in an 85% reduction in cell viability at 72 h compared to controls. Combining E2F-1 overexpression with roscovitine resulted in >99% reduction in cell viability by 72 h. Overexpression of E2F-1 resulted in premature S-phase entry and G2/M arrest at 24 h, followed by apoptosis by 72 h. Combining E2F-1 overexpression with roscovitine resulted in an earlier G2/M arrest, followed by a more complete, widespread apoptotic response by 24 h. Caspase 3/CPP32 activation and PARP cleavage in response to E2F-1 overexpression, alone and in combination with roscovitine, implicate the caspase cascade in E2F-1-mediated apoptosis of gastric cancer cells. Bax levels also increased in response to E2F-1 gene transfer, alone and in combination with roscovitine. E2F-1 overexpression induces widespread apoptosis in human gastric carcinoma cells. Combining E2F-1 overexpression with cyclin-dependent kinase inhibitors results in an enhanced apoptotic response, causing nearly complete gastric tumor cell death within 72 h. E2F-1 gene therapy in combination with cyclin dependent kinase inhibitors is a potentially active chemogene therapy strategy for the treatment of human gastric cancer.

Use of the laryngeal mask airway during repair of atrial septal defect in children

We describe the elective use of the laryngeal mask airway in two children undergoing cardiopulmonary bypass for repair of an atrial septal defect. Total surgical time was short and cardiopulmonary bypass performed at normothermia allowing removal of the laryngeal mask airway on the operating table on completion of surgery. We were able to adequately oxygenate and ventilate the children throughout the procedure using positive pressure ventilation and spontaneous ventilation. The use of caudal fentanyl and rectal diclofenac aided postoperative pain management. Atrial septal defect repair has become one of the more straightforward cardiac operations partly as a result of new cardiopulmonary bypass techniques. Avoidance of intubation and postoperative ventilation in appropriate patients would make this procedure ideal for 'fast tracking' and offers the potential advantages of decreased length of stay in hospital and reduction in overall costs.

Caspase activation and changes in Bcl-2 family member protein expression associated with E2F-1-mediated apoptosis in human esophageal cancer cells

The prognosis for patients with esophageal cancer remains poor, prompting the search for new treatment strategies. Overexpression of E2F-1 has been shown to induce apoptosis in several cancer cell types. In the present study, the effect of adenovirus-mediated E2F-1 overexpression on human esophageal cancer cell lines Yes-4 and Yes-6 was evaluated. Cells were treated by mock infection, infection with an adenoviral vector expressing beta-galactosidase (Ad5CMV-LacZ), or E2F-1 (Ad5CMVE2F-1). Western blot analysis confirmed marked overexpression of E2F-1 in Ad5CMVE2F-1-infected cells. Overexpression of E2F-1 resulted in marked growth inhibition and rapid loss of cell viability due to apoptosis, although Yes-6 cells were somewhat more resistant to E2F-1-mediated growth inhibition than Yes-4 cells. Cell cycle analysis revealed that overexpression of E2F-1 led to G2 arrest, followed by apoptotic cell death. p53 expression remained undetectable in both cell lines after E2F-1 overexpression. The apoptosis inhibitor proteins of the Bcl-2 gene family, Bcl-2, Mcl-1, and BcI-XL, decreased at 48 h after infection in Yes-4 cells, but remained unchanged in Yes-6 cells. Levels of retinoblastoma gene product (pRb) declined at 48 h after E2F-1 infection in Yes-4 cells, at which apoptosis predominated, whereas pRb expression remained constant in Yes-6 cells. Expression of p14ARF did not change after E2F-1 infection in either cell line. Involvement of caspase 3 and caspase 6 in E2F-1-mediated apoptosis was demonstrated by cleavage of caspase 3/CPP32 and poly-ADP-ribose polymerase, as well as fragmentation of the caspase 6 substrate, lamin B. These results indicate that the sensitivity of esophageal cancer cells to E2F-1-mediated apoptosis may be related to differential expression of Bcl-2 family member proteins and suggest that the adenovirus-mediated E2F-1 gene therapy may be a promising treatment strategy for the treatment of this disease.

Management of congenital tracheal stenosis: a multidisciplinary approach

Congenital tracheal stenosis is a rare but underdiagnosed anomaly which can present as life-threatening respiratory insufficiency in neonates and infants. Initial control of the airway is mandatory. Surgical correction is the mainstay of therapy and is achieved with low mortality. The type and extent of repair depends largely on the length of stenosis. Cardiac anomalies are frequently associated and may be addressed at the time of tracheal surgery. Despite initial satisfactory results, post-operative morbidity due to persistent granulation tissue is substantial. It is through a multidisciplinary approach and close follow-up of the repaired airway that these demanding patients are best cared for. The long-term quality of life remains uncertain.

Reduction of chemokine levels and leukocyte traffic to joints by tumor necrosis factor alpha blockade in patients with rheumatoid arthritis

OBJECTIVE

To verify the hypothesis that in rheumatoid arthritis (RA), tumor necrosis factor alpha (TNFalpha) plays a critical role in regulating leukocyte trafficking and chemokine levels.

METHODS

Ten patients with longstanding RA received a single 10 mg/kg infusion of anti-TNFalpha monoclonal antibody (cA2). The articular localization of autologous granulocytes, separated in vitro and labeled with 111In, was studied by analysis of gamma-camera images both before and 2 weeks after treatment. At the same sequential time points, synovial biopsy samples were assessed for infiltrating CD3+ T cells, CD22+ B cells, and CD68+ macrophages. Synovial tissue expression of the chemokines interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1), macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, Groalpha, and RANTES was also determined. Serum IL-8 and MCP-1 concentrations were measured by enzyme-linked immunosorbent assay.

RESULTS

Anti-TNFalpha therapy in RA significantly reduced 111In-labeled granulocyte migration into affected joints. There was a simultaneous and significant reduction in the numbers of infiltrating synovial CD3+ T cells, CD22+ B cells, and CD68+ macrophages and in the expression of IL-8 and MCP-1, with a trend toward a reduction in serum concentrations of these chemokines.

CONCLUSION

TNFalpha blockade reduces synovial expression of the chemokines IL-8 and MCP-1 and diminishes inflammatory cell migration into RA joints.

Adenovirus-mediated E2F-1 gene transfer efficiently induces apoptosis in melanoma cells

BACKGROUND

E2F-1 is a transcription factor that stimulates cellular proliferation and cell cycle progression from G(1) to S-phase. Somewhat paradoxically, E2F-1 also has the properties of a tumor suppressor. Overexpression of E2F-1 has been shown to induce apoptosis in some cancer cells. In the current study, the effect of adenovirus-mediated E2F-1 gene transfer on human melanoma cell growth was investigated.

METHODS

Two human melanoma cell lines, SK-MEL-28 (wild-type p53) and SK-MEL-2 (mutant p53), were treated by mock infection, infection with a control vector expressing the beta-galactosidase gene (Ad5CMV-LacZ), or infection with a vector expressing E2F-1 (Ad5CMV-E2F-1) at a multiplicity of infection of 100. Cell proliferation and viability were determined by WST-1 assay and trypan blue exclusion, respectively. Apoptosis was assessed by cell flow cytometry and confirmed by cell morphology, in situ terminal deoxynucleotidyl nick end labeling assay, and poly(ADP-ribose) polymerase cleavage assay.

RESULTS

Marked overexpression of E2F-1 was evident in both cell lines 24 hours after infection with Ad5CMVE2F-1 by Western blot analysis. E2F-1 overexpression resulted in growth inhibition and rapid loss of cell viability. Overexpression of E2F-1 also resulted in premature S-phase entry and G(2) arrest at 24 hours followed by apoptotic cell death at 48 hours. After Ad5CMVE2F-1 infection, expression of Bax and Bak was unchanged, whereas Mcl-1 levels decreased markedly. In SK-MEL-28 cells, Bcl-XL levels also declined after E2F-1 expression. Bcl-2 was undetectable in SK-MEL-28 cells but was increased in SK-MEL-2 cells in response to E2F-1 overexpression.

CONCLUSIONS

Adenovirus-mediated E2F-1 gene transfer efficiently induces widespread apoptosis in human melanoma cells. E2F-1 overexpression induced apoptosis in cell lines containing wild-type and mutant p53, suggesting that this effect does not require wild-type p53 function. Anti-apoptotic proteins of the Bcl-2 family, notably Mcl-1 and Bcl-XL, may be involved in mediating the response to E2F-1. These data suggest that adenovirus-mediated E2F-1 gene therapy may be effective in the treatment of melanoma.

Lung transplantation and life extension in children with cystic fibrosis

BACKGROUND

Lung transplantation has been available as therapy for end-stage lung disease since the early 1980s, but survival after transplantation remains poor, with continued controversy as to the survival benefit from the procedure. We examined the effect of lung or heart-lung transplantation on the survival of a cohort of children with cystic fibrosis and severe lung disease.

METHODS

Between May, 1988, and May, 1998, 124 children with cystic fibrosis were accepted for lung transplantation. 47 received transplants, 68 died while they awaited organs, and nine remained on the active waiting list. We constructed a proportional-hazards model that used variables of prognostic significance in this population. By including transplant status as a time-dependent covariate, we were able to calculate a hazard ratio for transplantation. Date of entry into the study was the date when children were added to the list for transplantation, and measurements were taken at this time. Children were accepted for transplantation if they had a life expectancy of 2 years or less, a poor quality of life, and no contraindications to transplantation.

FINDINGS

After 1 year, 35 (74%) children were still alive; after 5 years 12 (33%) children were alive. The univariate hazard ratio for transplantation was 0.41 (95% CI 0.23-0.74; p=0.003). Transplantation remained significantly associated with survival after correction for differences in age, sex, height-corrected forced expiratory volume in 1 s, minimum oxygen saturation during a 12 min walk, haemoglobin concentration, albumin concentration, and age-corrected resting heart rate (hazard ratio 0.31 [0.13-0.72]; p=0.007).

INTERPRETATION

If centres follow our criteria for accepting patients for transplantation, and achieve similar survival after transplantation, they could expect a survival benefit for their patients in line with our results.

A population pharmacokinetic-pharmacodynamic analysis of single doses of clenoliximab in patients with rheumatoid arthritis

Clenoliximab (IDEC-151) is a macaque-human chimeric monoclonal antibody (immunoglobulin G4) specific for the CD4 molecule on the surface of T lymphocytes. It is being studied in patients with rheumatoid arthritis in which T cell activation orchestrates inflammation and tissue damage. In this initial study in humans, the pharmacokinetics and pharmacodynamics of clenoliximab were investigated after single intravenous infusion. Blood was collected up to 12 weeks after dose administration to measure clenoliximab concentration, CD4+ T-cell count, CD4 antigen coating, and CD4 cell surface density. Clenoliximab displayed nonlinear pharmacokinetic behavior and caused an 80% reduction in CD4 density for up to 3 weeks, without depleting T cells. A pharmacokinetic-pharmacodynamic model was developed that described the relationship between antibody concentration, antigen coating, and the observed decreases in CD4 cell surface density. This was used to anticipate the effects of clenoliximab in untested regimens and optimize the design of future clinical trials.

Tracheal allograft reconstruction: the total North American and worldwide pediatric experiences

BACKGROUND

We reviewed both the North American and the total worldwide pediatric experience with tracheal allograft reconstruction as treatment for patients with long segment and recurrent tracheal stenosis.

METHODS

The stenosed tracheal segment is opened to widely patent segments. The anterior cartilage is resected and the posterior trachealis muscle or tracheal wall remains. A temporary silastic intraluminal stent is placed and absorbable sutures secure the chemically preserved cadaveric trachea. After initial success with this technique in Europe, several North American centers have now performed the procedure. The cumulative North American experience includes 6 patients (3 adults and 3 children). Worldwide, more than 100 adults and 31 children, aged 5 months to 18 years, with severe long segment tracheal stenosis have undergone tracheal allograft reconstruction.

RESULTS

In North America, 5 of 6 patients have survived, with one early death due to bleeding from a tracheal-innominate artery fistula in a previously irradiated neck. Worldwide, 26 children survived (26 of 31 = 84%) with follow-up from 5 months to 14 years. Only 1 of 26 pediatric survivors (1 of 26 = 3.8%) had a tracheostomy.

CONCLUSIONS

Tracheal allograft reconstruction demonstrates encouraging short- to medium-term results for patients with complex tracheal stenosis. Allograft luminal epithelialization supports the expectation of good long-term results.

Regulation of cytokines, cytokine inhibitors, and acute-phase proteins following anti-TNF-alpha therapy in rheumatoid arthritis

Treatment with a chimeric mAb to TNF-alpha has been shown to suppress inflammation and improve patient well-being in rheumatoid arthritis (RA), but the mechanisms of action of such treatment have not been fully explored. Here we show that in vivo administration of anti-TNF-alpha Ab, using a longitudinal analysis, results in the rapid down-regulation of a spectrum of cytokines, cytokine inhibitors, and acute-phase proteins. Marked diurnal variation in the serum levels of some of these were detected. These results were consistent with the concept of a cytokine-dependent cytokine cascade, and the degree of clinical benefit noted after anti-TNF-alpha therapy is probably due to the reduction in many proinflammatory mediators apart from TNF-alpha, such as IL-6, which reached normal levels within 24 h. Serum levels of cytokine inhibitors such as soluble p75 and p55 TNFR were reduced as was IL-1 receptor antagonist. Reductions in acute-phase proteins occurred after serum IL-6 fell and included serum amyloid A, haptoglobin, and fibrinogen. The latter reduction could be of importance, as it is a risk factor for atherosclerosis, which is augmented in RA patients.

Adenovirus-mediated E2F-1 gene transfer inhibits MDM2 expression and efficiently induces apoptosis in MDM2-overexpressing tumor cells

The oncoprotein MDM2 binds and inactivates p53. MDM2 also binds to the tumor suppressor pRB, as well as E2F-1. E2F-1 is a transcription factor that regulates S phase entry and has been shown to cause apoptosis in some cell types when overexpressed. To investigate the effect of adenovirus-mediated E2F-1 overexpression, MDM2-overexpressing tumor cell lines were treated by mock infection, infection with an adenoviral vector expressing beta galactosidase, or E2F-1 (Ad5CMV-E2F-1). Western blot analysis confirmed significant overexpression of E2F-1 in Ad5CMV-E2F-1-infected cells. E2F-1 overexpression resulted in marked growth inhibition and rapid loss of cell viability. Ad5CMV-E2F-1 infection resulted in early S phase entry, followed by apoptotic cell death. E2F-1 overexpression was associated with a marked decrease in MDM2 levels and no evidence of increased Bax levels, whereas p53 and Bcl-2 levels remained undetectable. Cleavage of poly-ADP-ribose polymerase and caspase 3/CPP32 implicated activation of the caspase cascade in E2F-1-mediated apoptosis. These results indicate that adenovirus-mediated E2F-1 overexpression in MDM2-overexpressing tumor cells results in decreased MDM2 expression and widespread apoptosis. Because MDM2-overexpressing tumors are often resistant to p53 gene therapy, adenovirus-mediated E2F-1 gene therapy may be a promising alternative strategy.

Zanamivir in the prevention of influenza among healthy adults: a randomized controlled trial

CONTEXT

The neuraminidase inhibitor zanamivir, a sialic acid analog administered directly to the respiratory tract, has been demonstrated in clinical studies to be effective in treatment of type A and B influenza. It has also been shown to prevent influenza infection and disease in an experimental model.

OBJECTIVE

To examine the efficacy of zanamivir, administered once daily, in the prevention of influenza infection and disease.

DESIGN

Double-blind, randomized, placebo-controlled trial.

SETTING

Two midwestern university communities.

PARTICIPANTS

A total of 1107 healthy adults (mean age [range], 29 [18-69] years) were recruited in November 1997, before the influenza season.

INTERVENTION

At the start of the influenza outbreak, 554 subjects were randomized to receive placebo and 553 to receive zanamivir. The drug, 10 mg once per day, or identical placebo was administered by oral inhalation for a 4-week period.

MAIN OUTCOME MEASURES

Illness occurrence was recorded by participants daily and records were evaluated weekly. Specimens were collected for viral isolation when symptoms were reported within 3 days of illness onset. Infection was also identified by testing paired serum samples for rise in antibody titer against the circulating influenza viruses.

RESULTS

Zanamivir was 67% efficacious (95% confidence interval [CI], 39%-83%; P<.001) in preventing laboratory-confirmed clinical influenza meeting the case definition and 84% efficacious (95% CI, 55%-94%; P=.001) in preventing laboratory-confirmed illnesses with fever. All influenza infections occurring during the season, with or without symptoms, were prevented with an efficacy of 31% (95% CI, 4%-50%; P=.03). The nature and incidence of adverse events in the zanamivir group did not differ from placebo. Compliance with the once-daily dosage was high.

CONCLUSIONS

Zanamivir administered once daily is efficacious and well tolerated in the prevention of influenza for a 4-week period in healthy adults.

Bcl-2 inhibits early apoptotic events and reveals post-mitotic multinucleation without affecting cell cycle arrest in human epithelial tumor cells exposed to etoposide

Defective apoptotic mechanisms are considered to play a role in both the development of malignancy and resistance to chemotherapeutic drugs. The Bcl-2 family of proteins regulate the cellular commitment to survive or die when challenged with various apoptotic stimuli.

PURPOSE

The purpose of this study was to identify the point at which Bcl-2 interrupts the apoptotic cascade initiated following exposure of human tumor cells to etoposide.

METHODS

A stable Bcl-2-expressing HeLa-transfected clonal cell line, along with its control-vector-transfected counterpart, were utilized in this study. Following etoposide exposure, cells were examined for cell cycle arrest, formation of hyperdiploid cells, apoptotic DNA degradation, loss of plasma membrane integrity, levels of expression of members of the Bcl-2 protein family, caspase activation, degradation of poly(ADP-ribose) polymerase and movement of Bax from cytosol to cellular membrane fractions.

RESULTS

Caspase activation, poly(ADP-ribose) polymerase degradation and Bax membrane insertion were initiated rapidly following etoposide removal, concomitantly with cell cycle arrest. Whereas Bcl-2 had no effect on etoposide-induced cell arrest, it interrupted all aspects of apoptosis, including activation of caspases, poly(ADP-ribose) polymerase degradation, DNA fragmentation and loss of plasma membrane integrity. Surprisingly, Bcl-2 also blocked Bax membrane insertion. In addition, Bcl-2 also prevented the increase in cellular levels of Bak, Bax and Bcl-xL, along with degradation of actin and Bax. However, inhibition of etoposide-induced apoptosis by Bcl-2 resulted in the accumulation of giant, multinucleated cells that eventually lost the ability to exclude trypan blue without apoptotic morphology or DNA degradation.

CONCLUSIONS

These results indicate that biochemical apoptotic processes are initiated concomitant with etoposide-induced cell cycle arrest and are interrupted by Bcl-2 overexpression. However, the aberrant mitotic events induced by etoposide are sufficient to kill these cells even in the absence of apoptosis.

A successful modification of ultrafiltration for cardiopulmonary bypass in children

Total body water (TBW) is increased after cardiopulmonary bypass (CPB) resulting in tissue oedema and organ dysfunction. Ultrafiltration has been used to reduce this accumulation of water, although conventional ultrafiltration seemed ineffective in reducing the rise in TBW after CPB in our clinical experience. We describe a modified technique in which ultrafiltration is performed in the first 10 minutes after the patient is weaned from bypass, returning nearly all the blood in the circuit to the patient and elevating the haematocrit (Hct) to any predetermined level. We carried out a pilot study on 21 children aged 4-144 months undergoing open-heart surgery and CPB for congenital heart defects. They were divided into three comparable groups: (1) controls (n = 6); (2) conventional ultrafiltration (n = 7); and (3) modified ultrafiltration (n = 8). TBW (bio-impedance), Hct, osmolality, mean corpuscular volume and mean corpuscular haemoglobin concentration were recorded at frequent intervals. Control patients showed elevation of TBW by 18.2% median (range 14.5-20.3), conventional ultrafiltration by 12.4% (7.9-15.0), modified ultrafiltration by 5.7% (4.5-7.1) (p less than 0.0001 compared to controls, p. less than 0.005 compared to conventional ultrafiltration, Mann-Whitney U test). Hct could be elevated to preoperative levels only by the modified method. Mean corpuscular volume, and mean corpuscular haemoglobin concentration osmolality were unaltered. Ultrafiltration by the modified method was more effective than conventional ultrafiltration in reducing the rise in TBW and elevating Hct after CPB.