ß-Alkylated oligomaltosides as new alternative preservatives: antimicrobial activity, cytotoxicity and preliminary investigation of their mechanism of action.

AIM: The need for developing efficient and safe alternatives to parabens has been growing in the cosmetic and pharmaceutical industries. To this end, the antimicrobial activities and safety of methyl-ß-d-maltoside, methyl-ß-d-maltotrioside and their dodecyl homologues were investigated. METHODS AND RESULTS: Antimicrobial activities of methyl- and dodecyl-ß-d-oligomaltoside have been tested on European pharmacopoeia reference strains. When effective, minimal inhibitory concentrations ranged from 32 to 1024 mg l(-1) . Methyl derivatives exhibited greater antibacterial properties, while their dodecyl homologues were more active on fungal strains. To elucidate the mechanism of action of methyl compounds, enzymatic inhibition assays of key maltose metabolism enzymes have been conducted. Methyl-ß-maltotrioside (MeG3) was found to be effective in inhibiting microbial glucoamylase and α-amylase. MeG3 and dodecyl-ß-maltotrioside cytotoxicity were also checked on HepG2 cells and were found to be low, compared with benzalkonium chloride or parabens. CONCLUSION: Methyl- and dodecyl-ß-maltoside or maltotrioside were found to be active against reference strains used for preservatives efficacy testing. Methyl derivatives could act through an interesting inhibition of the microbial enzymatic metabolism. SIGNIFICANCE AND IMPACT OF THE STUDY: Given their very simple chemical structure, low toxicity and good antimicrobial activity, methyl-ß-d-oligomaltosides could represent a valuable alternative to currently used preservatives such as parabens.

Impact of transesophageal electrophysiologic study to elucidate the mechanism of arrhythmia on children with supraventricular tachycardia and no preexcitation.

An electrophysiologic study (EPS) of children and teenagers with paroxysmal supraventricular tachycardia (SVT) and normal electrocardiography (ECG) in sinus rhythm was evaluated. Generally, EPS is performed only before paroxysmal SVT ablation in these patients. In this study, 140 patients (mean age, 15 ± 3 years) with normal ECG in sinus rhythm were studied for SVT by a transesophageal route in baseline state and after isoproterenol. Idiopathic left or right ventricular tachycardia was diagnosed in four patients (3 %). Anterograde conduction over an atrioventricular (AV) left lateral (n = 10) or septal (n = 9) accessory pathway (AP) was noted in 19 patients (13.5 %) at atrial pacing. Orthodromic AV reentrant tachycardia (AVRT) was induced in these children. Five of the patients had a high rate conducted over AP (>240 bpm in baseline state or >290 bpm after isoproterenol). Two of the patients (a 10-year-old girl with well-tolerated SVT and a 17-year-old with syncope-related SVT) had the criteria for a malignant form with the induction of atrial fibrillation conducted over AP at a rate exceeding 290 bpm in baseline state. Of the 140 patients, 74 (53 %) had typical AV node reentrant tachycardia (AVNRT), nine had atypical AVNRT (6 %), 1 had atrial tachycardia (0.7 %), and 33 (23.5 %) had AVRT related to a concealed AP with only retrograde conduction. Electrophysiologic study is recommended for children with paroxysmal SVT and normal ECG in sinus rhythm. The data are helpful for guiding the treatment. Ventricular tachycardia or atrial tachycardia can be misdiagnosed. Masked preexcitation syndrome with anterograde conduction through AP was present in 13.5 % of the patients, and 1.4 % had a malignant preexcitation syndrome.

Evaluation of the clinical and economic impact of delays to surgery in patients with periampullary cancer.

Background: Early treatment is the only potential cure for periampullary cancer. The pathway to surgery is complex and involves multiple procedures across local and specialist hospitals. The aim of this study was to analyse variability within this pathway, and its impact on cost and outcomes. Methods: Patients undergoing surgery for periampullary cancer (2011-2016) were identified retrospectively and their pathway to surgery was analysed. Patients who had early surgery (shortest quartile, Q1) were compared with those having late surgery (longest quartile, Q4). Results: A total of 483 patients were included in the study, with 121 and 124 patients in Q1 and Q4 respectively. The median time from initial CT to surgery was 21 days for Q1 versus 112 days for Q4 (P < 0·001). Diagnostic delays were common in Q4; these patients required significantly more investigations than those in Q1 (endoscopic ultrasonography (EUS): 74·2 versus 18·2 per cent respectively, P < 0·001; MRI: 33·6 versus 20·6 per cent, P = 0·036). The median time to diagnostic EUS was 13 days in Q1 versus 59 days in Q4 (P < 0·001). Some 42·1 per cent of jaundiced patients in Q1 underwent preoperative biliary drainage, compared with all patients in Q4. There were significantly more unplanned admissions and associated longer duration of hospital stay per patient and costs in Q4 than in Q1 (median: 8 versus 3 days respectively; €5652 versus €2088; both P < 0·001). There was a higher likelihood of potentially curative surgery in Q1 (82·6 per cent versus 66·9 per cent in Q4; P = 0·005). Conclusion: There is wide variation across the entire pathway, suggesting that multiple strategies are required to enable early surgery. Defining an effective pathway by anticipating the need for investigations and avoiding biliary drainage reduces unplanned admissions and costs and increases resection rates.

Development and multicentre validation of a prognostic model to predict resectability of pancreatic head malignancy.

BACKGROUND: At the time of planned pancreatoduodenectomy patients frequently undergo exploratory laparotomy without resection, leading to delayed systemic therapy. This study aimed to develop and validate a prognostic model for the preoperative prediction of resectability of pancreatic head tumours. METHODS: This was a retrospective study of patients undergoing attempted resection for confirmed malignant tumours of the pancreatic head in a university hospital in Hannover, Germany. The prognostic value of patient and tumour characteristics was investigated in a multivariable logistic regression model. External validation was performed using data from two other centres. RESULTS: Some 109 patients were included in the development cohort, with 51 and 175 patients in the two validation cohorts. Eighty patients (73·4 per cent) in the development cohort underwent resection, and 37 (73 per cent) and 141 (80·6 per cent) in the validation cohorts. The main reasons for performing no resection in the development cohort were: local invasion of vasculature or arterial abutment (15 patients, 52 per cent), and liver (12, 41 per cent), peritoneal (8, 28 per cent) and aortocaval lymph node (6, 21 per cent) metastases. The final model contained the following variables: time to surgery (odds ratio (OR) 0·99, 95 per cent c.i. 0·98 to 0·99), carbohydrate antigen 19-9 concentration (OR 0·99, 0·99 to 0·99), jaundice (OR 4·45, 1·21 to 16·36) and back pain (OR 0·02, 0·00 to 0·22), with an area under the receiver operating characteristic (ROC) curve (AUROC) of 0·918 in the development cohort. AUROC values were 0·813 and 0·761 in the validation cohorts. The positive predictive value of the final model for prediction of resectability was 98·0 per cent in the development cohort, and 91·7 and 94·7 per cent in the two external validation cohorts. [Corrections added on 18 July 2018, after first online publication: The figures for OR of the variables time to surgery and CA19-9 in the abstract and in Table 3 and Table 4 were amended from 1·00 to 0·99]. CONCLUSION: For preoperative prediction of the likelihood of resectability of pancreatic head tumours, this validated model is a valuable addition to CT findings.

Influence of DNA repair polymorphisms on biomarkers of genotoxic damage in peripheral lymphocytes of healthy subjects.

DNA repair polymorphisms may represent susceptibility factors affecting DNA integrity, and possibly cancer risk, in human population. In order to elucidate the influence of a few widely studied DNA repair polymorphisms on individual levels of DNA damage and their possible interaction with lifestyle and environmental exposures, 171 subjects from a well-characterized human population enrolled in a previous study on genetic effects of air pollution were genotyped for the XRCC1 Arg280His and Arg399Glu, XRCC3 Thr241Met and ERCC2 Lys751Gln polymorphisms. The association between DNA repair genotype, alone or in combination with metabolic genotype, on the levels of SCE, micronuclei and tail moment values in peripheral lymphocytes was evaluated. A significant influence of the ERCC2 genotype on SCE frequency was observed. Subjects with ERCC2 751 Gln/Gln genotype had significantly higher risk of high (above the median) SCE/cell with respect to Lys/Lys referents (OR 4.55, 95% CI 1.48-13.99). A non-significantly elevated OR was also observed in Gln/Lys heterozygotes, suggesting a gene dosage effect. When subjects were categorized by smoking habits and professional exposure, the variant ERCC2 751 Gln/Gln genotype was associated with elevated SCE rates in non-smokers and in exposed subjects, but not in smokers. The results of this study support the hypothesis that some DNA repair polymorphisms exert a modifying effect on individual levels of DNA damage in healthy subjects, possibly also modulating cancer risk.

[Implantable cardioverter defibrillators in pediatric patients: results in a series of 33 cases]. / Le défibrillateur automatique implantable chez l'enfant et l'adolescent: indications, complications et résultats à propos d'une étude multicentrique française de 33 cas.

UNLABELLED: Implantable defibrillator is the recognized treatment of sudden cardiac death. Miniaturization of the devices allows implantation in children. METHODS: This multicentric retrospective study analyzed data of 33 children aged 18 years and less who were implanted from 1990 to 2005. RESULTS: Age of patients are 10 to 18 years, 20 patients were implanted after a resuscitation of sudden death, 10 after a syncope, 2 after a ventricular tachycardia and 1 in a prophylactic way. Tachycardias on primary electrical disease are most frequent (46%). Hypertrophic cardiomyopathy accounts for 22%, DAVD for 14%, congenital cardiopathies for 12%. Seventeen patients received appropriate shocks and 14 patients had inappropriate shocks. There were two unexplained deaths. Five leads fractures and two device infections were noted. CONCLUSION: Implantable defibrillator is an effective treatment for children high-risk of sudden death. Occurrence of inappropriate shocks due to sinusal tachycardia, infections and leads fractures are frequent.

Follow-up results of transvenous occlusion of patent ductus arteriosus with the buttoned device.

OBJECTIVES: The purpose of this presentation is to document results of buttoned device (BD) occlusion of patent ductus arteriosus (PDA) in a large number of patients with particular emphasis on long-term follow-up in an attempt to provide evidence for feasibility, safety and effectiveness of this method of PDA closure. BACKGROUND: Immediate and short-term results of BD occlusion of PDA have been documented in a limited number of children. METHODS: During a six-year period ending August 1996, transcatheter BD closure of PDA was attempted in 284 patients, ages 0.3 to 92 years (median 7) under a protocol approved by the local institutional review boards and FDA with an investigational device exemption in U.S. cases. RESULTS: The PDAs measured 1 to 15 mm (median 4) at the narrowest diameter; 20 were larger than 8 mm and 10 larger than 10 mm. They were occluded with devices measuring from 15 to 35 mm delivered via 7F (N = 140) or 8F (N = 144) sheaths. Successful implantation of the device was accomplished in 278 (98%) of 284 patients. The Qp:Qs decreased from 1.8+/-0.6 (mean+/-SD) to 1.09+/-0.19 (p < 0.001). Effective occlusion defined as no (N = 167 [60%]) or trivial (N = 79 [28%]) residual shunt was achieved in 246 (88%) patients. All types of PDAs, irrespective of the shape (conical, tubular or short), size (small or large) or length (short or long) of the PDA and previously implanted Rashkind devices, could be occluded. Follow-up data, 1 to 60 months (median 24) after device implantation, were available in 234 (84%) patients. Seven (3%) patients required reintervention to treat residual shunt with (N = 2) or without (N = 5) hemolysis. Actuarial reintervention-free rates were 95% at 1 and 5 years. There was gradual reduction of actuarial residual shunts and were 40%, 28%, 21%, 14%, 11%, 10%, 6% and 0% respectively at 1 day, 1, 6, 12, 24, 36, 48 and 60 months after device implantation. Incorporation of folding plug over the button loop in 10 additional patients produced immediate and complete occlusion of PDA. CONCLUSIONS: This large multiinstitutional experience confirms the feasibility, safety and effectiveness of buttoned device closure of PDAs. All types of PDAs irrespective of the shape, length and diameter can be effectively occluded. Incorporation of folding plug over the button loop produces complete PDA occlusion at the time of device implantation.

[Feasibility and significance of a transoesophageal electrophysiological investigation in children and adolescents with Wolff-Parkinson-White syndrome]. / Faisabilité et intérêts de l'étude électrophysiologique par voie transoesophagienne dans le syndrome de Wolff-Parkinson-White de l'enfant et de l'adolescent.

UNLABELLED: An electrophysiological investigation is the most reliable means of detecting malignant forms of Wolff-Parkinson-White syndrome (WPW). However, an endocavity investigation is an invasive procedure, especially in young subjects with few symptoms. The aim of this study was to examine the feasibility and results of an electrophysiological study performed by the transoesophageal route in children with WPW. The study was performed in 70 children aged between 11 and 19 years (mean 15 +/- 3) with an obvious ECG appearance of WPW: 13 had dizziness or syncope (group I), 25 had tachycardia (group II) and 32 were asymptomatic (group III). The ages were similar in all three groups. The transoesophageal electrophysiological investigation without premedication consisted of atrial stimulation at increasing frequencies and programmed atrial stimulation using one and two extra stimuli delivered in the basal state and after infusion of 2 to 5 microg of isoproterenol. RESULTS: The investigation was completed in all the children except one in group II. A paroxysmal junctional tachycardia was induced in 7 group I children (54%), 22 in group II (92%) and 4 in group III (12.5%). Atrial fibrillation lasting more than one minute was induced in 7 group I children (54%), 6 in group II (25%) and 6 in group III (19%). The percentage of malignant forms combining rapid conduction in the bundle of Kent at a rate of more than 240/min in the basal state or more than 300/min with isoproterenol, and atrial fibrillation was 54% in group I, 21% in group II, and 22% in group III. In conclusion, a transoesophageal electrophysiological investigation was possible as an outpatient procedure in children older than 10 years, and allowed the detection of potentially serious forms whatever the indication for the investigation, with nevertheless a significantly higher incidence in those presenting with dizziness or syncope. The incidence of 22% for potentially malignant forms in asymptomatic children provides an incentive to recommend an ECG in all children older than 10 years participating in an active sport in order to detect WPW and to propose oesophageal investigation.

[Paediatric cardiac surgery and autoevaluation: risk score, complexity score and graphic analysis]. / Chirurgie cardiaque pédiatrique et auto-évaluation: score de risque, score de complexité et analyses graphiques.

The creation of a paediatric surgical unit requires autoevaluation in order to: assess the quality of the results with respect to recognised international standards, answer the family's questions about the results obtained and adhere to criteria of accreditation Between January 2003 and December 2004, 201 consecutive patients, children (N= 164) or operated for adult congenital heart disease (N= 37) were treated. No patient was excluded. The RACHS-1 risk score, the ARISTOTLE scores of complexity and performance and the CUSUM and VLAD graphic analyses were applied to the study of hospital mortality. An original "variable performance-adjusted display" (VPAD) graphic analysis was performed to show up any possible variations of performance. Paediatric hospital survival was 97.56% (95% CI: 93.9 - 99.1). The paediatric complexity and performance scores were 6.79 +/- 0.22 and 6.62 respectively. In the absence of statistical significance in this field of autoevaluation, graphic analyses indicated the performance of our unit with no "learning" curves. Graphic scores and analyses allow assessment of the function of a paediatric cardiac surgical unit and the variations of complexity with respect to time, before the appearance of statistical significance. The ARISTOTLE complexity and performance scores and their adaptation in VPAD seem to be more reliable and discriminating than the RACHS-1 score.

[Complications of prostaglandin E1 treatment of congenital heart disease in paediatric medical intensive care]. / Complications du traitement par prostaglandines E1 des cardiopathies congénitales en réanimation médicale pédiatrique.

The authors undertook a retrospective study of the modes of prescription, the tolerance and efficacy of prostaglandin E1 in 62 consecutive neonates with congenital heart disease (average Age 1.6 days: 35 boys: weight: 3.1 +/- 0.6 Kg) admitted to the paediatric intensive care unit of Nancy University Hospital between 1998 and 2002. The infusion time and cumulative dosage were 134 +/- 112 (6-480) hours and 111 +/- 94 (4-396) microg/Kg respectively. The side effects that were observed were: Apnoea (19%), abdominal distension (16%), bradycardia (13%), enterocolitis (6.5%), hypotension (6.5%), vomiting (5%), fever (1.6%) and skin rash (1.6%). Gastrointestinal disturbances are associated with a low body weight (p<0.04), to prolonged treatment (p<0.02) with no influence of initial or cumulative dosages (P=NS), with respiratory assistance (p<0.03) and longer hospital stay (p<0.01). Hypotension was commoner in cases of poor neonatal adaptation. Mortality was correlated with severe initial acidosis (p<0.02), a low Apgar score, the initial prolonged use of high doses of prostaglandin (p<0.04), and the presence of severe valvular aortic stenosis or hypoplasia of the left heart (p<0.002). The authors conclude that treatment with prostaglandin is effective in the majority of cases despite the use of low maintenance doses (0.01 microg/Kg/min). Gastrointestinal disturbances favourised by the perinatal context, the cardiac disease, and prolonged treatment are significant factors for morbidity and mortality. The beneficial role of early neonatal enteral feeding was not demonstrated in this high risk population.

Human-hamster hybrid cells used as models to investigate species-specific factors modulating the efficiency of repair of UV-induced DNA damage.

The human-Chinese hamster hybrid cell line XR-C1#8, containing human chromosome 8, was used as a model system to investigate the relative importance of cellular enzymatic environment and chromosomal structure for modulating the efficiency of repair of UV-induced DNA damage. The hybrid cells were irradiated with UVC light and the extent of cytogenetic damage, detected as frequencies of sister chromatid exchanges (SCEs), was compared between the human and the hamster chromosomes. The combination of immunofluorescent staining for SCEs and chromosome painting with fluorescence in situ hybridization allowed the simultaneous analysis of SCEs in the human and hamster chromosomes. The aim of the present study was to determine if the differences in biological response to comparable UV treatments observed between human and hamster cells were maintained in the hybrid cells in which human and hamster chromosomes are exposed in the same cellular environment. The analysis of replication time of human chromosome 8 indicated the active status of this chromosome in XR-C1#8 hybrid cells. The frequencies of SCEs for human chromosome 8 and a hamster chromosome of comparable size were 0.35 +/- 0.52, 0.80 +/- 0.73, 1.24 +/- 2.24 and 0.36 +/- 0.12, 0.71 +/- 0.2, 0.97 +/- 0.27, respectively, after irradiation with 0, 5, and 10 J/m2. The persistence of UV-induced SCEs after three cell cycles was also analyzed, both for the human and hamster chromosomes. The observed frequencies of SCEs were 0.40 +/- 0.57, 0.62 +/- 1.05, 0.58 +/- 0.83 and 0.26 +/- 0.08, 0.67 +/- 0.18, 0.69 +/- 0.24, in human and hamster chromosomes respectively, after treatment with 0, 10, and 20 J/m2 of UVC light. No significant differences could be observed between the human and hamster chromosomes. These results suggest that the enzymatic environment of human and hamster cells has the main role, in comparison to the structural organization of human and hamster chromosomes, for determining the different level of repair of UV-induced DNA damage observed in these two species.

Assessment of right ventricular outflow tract in children by two-dimensional echocardiography using a new subcostal view. Angiocardiographic and morphologic correlative study.

Evaluation of the right ventricular (RV) outflow tract in congenital heart disease is extremely important for surgical management. Therefore, the value of 2-dimensional echocardiography (2-D echo) to assess the RV outflow tract was studied using a new approach: the subcostal elongated right oblique view. Twenty normal children and 49 children with congenital heart disease, aged 1 day to 11 years, were studied. Significant pulmonary infundibular obstruction was present in 22 patients with conotruncal malformations. To obtain the subcostal elongated right oblique view from the short-axis view at the aortic valve level, the transducer was slightly rotated clockwise with an anterior angulation of about 30 degrees so that the ascending aorta was seen in its long axis, providing an image similar to that obtained by a right ventriculogram in the elongated right anterior oblique view. The deviation of infundibular septum was appreciated by measurement of the angle alpha, defined by the long axis of the infundibular septum and the plane of aortic cusps. This view could be obtained in 64 patients (92%). In correlation with angiographic or anatomic data, the subcostal elongated right oblique view permitted recognition of several types of RV outflow tract: type I--normally formed RV outflow tract; type II--disorganized RV outflow tract with obstruction (alpha less than 90 degrees); type III and IV--disorganized RV outflow tract with obstruction (alpha greater than 90 degrees). This view could visualize the crista supraventricularis in type I, but also the anatomic components of RV outflow tract that may contribute to obstruction in the other types: infundibular septum, septoparietal trabeculations and trabecula septomarginalis.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of sustained ventricular tachycardia after surgical repair of tetralogy of Fallot.

Between 1980 and 1996, 89 unselected consecutive patients with repaired tetralogy of Fallot (TOF) underwent examination, including a prospective right ventricular programmed stimulation with the same protocol (S1 S2, S3, S4). Age at surgery was 4.2 +/- 3.5 years and age at electrophysiologic study was 10.9 +/- 6.5 years. Follow-up since surgery was 14.4 +/- 4.8 years and patient follow-up after programmed stimulation was 7.8 +/- 4.2 years. The aim of this study was to evaluate the main predictors of the inducibility of a sustained monomorphic ventricular tachycardia (VT) and its significance to identify a group of patients at risk of sudden death: 21 (group A) had and 68 (group B) had no induced sustained VT. The induction of VT was related to older age at programmed stimulation, prolonged QRS duration, presence of complex ventricular arrhythmia, symptoms, right ventricular overload, and increased right ventricular systolic pressure. Predictors of induced VT selected by multivariate analysis were age at electrophysiologic study (p <0.0001), previous palliative shunts (p <0.001), right ventricular systolic pressure (p <0.007), and symptoms (p <0.005). Among group A patients, 4 had previous sustained VT before stimulation, and 1 had sustained VT only during follow-up after stimulation. No patients of group B had clinical sustained VT. Late mortality was low but similar between both groups. A negative electrophysiologic study may be helpful for the management of patients after surgical repair of TOF, but because the arrhythmic event rate is low, the findings of even a positive electrophysiologic study should be interpreted with caution.

Right ventricular overload and induced sustained ventricular tachycardia in operatively "repaired" tetralogy of Fallot.

The aim of the study was to evaluate the main predictors of the inducibility of sustained ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot. Thirty-five patients (age 12 +/- 6 years) underwent right-sided cardiac catheterization, echocardiography, radionuclide angiography and ventricular stimulation; 10 had (group 1) and 25 had no (group 2) sustained VT. Group 1 patients were significantly older at the time of surgery and had longer follow-up periods (7 +/- 3 vs 4 +/- 4 years, p less than 0.02; and 12 +/- 4 vs 5 +/- 2 years, p less than 0.001, respectively). Right ventricular (RV) systolic pressure, end-systolic and end-diastolic normalized RV volumes were higher in group 1 (48 +/- 14 vs 38 +/- 11 mm Hg, p less than 0.05; 1.23 +/- 0.2 vs 0.86 +/- 0.17, p less than 0.001; and 2.35 +/- 0.37 vs 1.70 +/- 0.22, p less than 0.001, respectively). RV end-diastolic pressure, left ventricular and RV ejection fractions were similar in the 2 groups. A stepwise discriminant analysis was made to predict patients with inducible sustained VT (group 1): Time period from surgery to follow-up (p less than 0.001), normalized RV end-systolic volume (p less than 0.002) and RV systolic pressure (p = 0.01) were higher in group 1 and allowed classification of 90% of patients in group 1 and 96% in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

No evidence for linkage to the type 1 or type 2 neurofibromatosis loci in Noonan syndrome families.

A linkage analysis has been performed on 6 two-generation families with classical Noonan syndrome to determine whether the syndrome is linked to neurofibromatosis type 1 on chromosome 17q or to neurofibromatosis type 2 on chromosome 22q. A significantly negative location score was obtained between 10 cM centromeric to and 15 cM telomeric from the neurofibromatosis type 1 locus. A significantly negative lod score was obtained with a marker mapping within the region where neurofibromatosis type 2 is thought to be located. These data indicate that Noonan syndrome is not tightly linked to either neurofibromatosis type 1 or type 2.

Surgical management of progressive pulmonary venous obstruction after repair of total anomalous pulmonary venous connection.

BACKGROUND: The occurrence of a progressive pulmonary venous obstruction after the repair of the total anomalous pulmonary venous connection is a severe complication. OBJECTIVES: The objectives of this study were to retrospectively review the patients with this condition and to report our experience with a new surgical technique with a sutureless in situ pericardium repair. METHODS: Of 178 patients who underwent correction of total anomalous pulmonary venous connection, 16 patients (9%) experienced the development of a progressive pulmonary venous obstruction in a median interval of 4 months (5 weeks-12 years). Three patients had isolated anastomotic stenosis, 4 patients had isolated pulmonary venous ostial stenosis, and 9 patients had both. Pulmonary venous obstruction was bilateral in 7 patients. The surgical procedures used at reoperation included 8 patch enlargements, 5 ostial endarterectomies, 1 intraoperative stenting, and 7 sutureless in situ pericardium repairs. RESULTS: There were 4 deaths after reoperation (4 of 15 patients; 27%). The only significant mortality risk factor was the bilateral location of the pulmonary venous obstruction (P =.045). In patients with isolated anastomotic stenosis or with only 1 pulmonary venous ostial stenosis (n = 5), there was no death, except the patient presenting with a single ventricle. In patients with 2 or more pulmonary venous ostial stenoses (n = 10), there were 3 deaths; 5 of the 7 survivors were successfully treated with the in situ pericardial technique, with normalized pulmonary artery pressure at a mean follow-up of 26 months. CONCLUSION: Progressive pulmonary venous stenosis after repair of total anomalous pulmonary venous connection remains a severe complication when bilateral. The sutureless in situ pericardial repair offers a satisfactory solution, particularly on the right side.

Genetic effects of petroleum fuels: II. Analysis of chromosome loss and hyperploidy in peripheral lymphocytes of gasoline station attendants.

Molecular cytogenetic methods were applied to investigate the effect of the occupational exposure to low concentrations of benzene and petroleum fuels on genomic stability. Twelve male gasoline station attendants (average benzene exposure of 0.32 mg/m3 as 8h TWA) and 12 age- and smoking-matched unexposed controls were selected for the study. The incidence of hyperploidy and polyploidy in peripheral lymphocytes was evaluated through in situ hybridization of interphase cells, harvested 24 hr after stimulation, with centromeric probes of chromosomes 7, 11, 18, and X. For half of the subjects, metaphases harvested 24 hr later were analyzed. The incidence of chromosome loss in vitro was determined in cytokinesis-blocked cells, harvested at 66 hr, through the hybridization of micronuclei with a pancentromeric probe. Ten thousand chromosomes (more than 200 metaphases equivalent) and 2,000 binucleated cells/person were scored for hyperploidy and micronucleus analysis, respectively. The results obtained did not show any exposure-related excess of hyperploidy or micronucleus formation. Conversely, the age of the subjects was significantly correlated with several markers of genomic instability, such as the incidence of chromosome X and chromosome 18 hyperploidy, total hyperploidy and polyploidy, and close to statistical significance with chromosome loss. Smoking habits did not appear to contribute significantly to the effects measured. The parallel analysis of hyperploidy and polyploidy in interphase nuclei in 24-hr cultures and in metaphase cells harvested 24 hr later showed basically similar incidences of aneuploid cells, indicating that no significant selection against hyperploid and polyploid types occurred during the first cell cycle in vitro.

Analysis of micronuclei in peripheral blood lymphocytes of traffic wardens: effects of exposure, metabolic genotypes, and inhibition of excision repair in vitro by ARA-C.

The cytokinesis-block micronucleus (MN) assay in peripheral lymphocytes was used to assess the genetic effects of the occupational exposure to traffic fumes in policemen from the Municipality of Rome. The study population consisted of 192 subjects engaged in traffic control (exposed, 134 subjects), or in office work (controls, 58 subjects). Groups were balanced for age, gender, and smoking habits. The average benzene exposure during the workshift was 9.5 and 3.8 microg/m(3) in exposed individuals and controls, respectively. All subjects were genotyped for CYP1A1, CYP2E1, GSTM1, GSTT1, and DT-diaphorase polymorphisms. The incidence of micronuclei and micronucleated cells was recorded in 1,000 binucleated cells harvested 66 hr after mitogen stimulation. Regression analysis of data showed that MN frequency was mainly modulated by the age (P = 0.001) and gender (P = 0.001) of the study subjects (relatively higher in the elderly and females), whereas it was unaffected by the occupational exposure to traffic fumes and smoking habits. A weak (P = 0.02) association between lower MN frequency and the GSTM1 null genotype was also observed. In order to improve the sensitivity of the method to excision-repairable lesions, a modified protocol, with exposure of cells to the repair inhibitor cytosine arabinoside (Ara-C) during the first 16 hr of growth, was applied to 78 subjects (46 exposed and 32 controls). The results confirmed the higher MN frequency in females (P < 0.05), but failed to demonstrate any significant effect of chemical exposure (occupational or related to smoking habits). When the frequency of MN induced by Ara-C (i.e., spontaneous values subtracted) was considered, a significant inverse correlation with age was observed (P = 0.005), possibly related to the age-dependent decrease in repair proficiency.

Recombination between homologous chromosomes does not play a dominant role in the formation of radiation-induced chromosomal aberrations.

PURPOSE: In mammalian cells, the relevance of homologous recombination in radiation-induced double-strand break (DSB) repair is not yet well understood. In the present work, the role of recombination between homologous chromosomes and homology-directed repair of DSB were studied, using X-ray-induced chromosomal aberrations as an end-point. MATERIALS AND METHODS: Human-hamster hybrid cells containing one or two copies of human chromosome 8 were used. If recombination between homologous chromosomes plays a dominant role in DSB repair, it is expected that X-irradiation of cells with two copies of chromosome 8 would result in a lower frequency of aberrations involving this chromosome compared with cells with only one copy of chromosome 8. The aberrations involving human chromosome 8 were detected by fluorescence in situ hybridization (FISH). Furthermore, a comparison between the hamster cell line XR-C1 (defective in non-homologous repair), CHO-9 (the wild-type cells) and the cell line XR-C1#8 (in which the defect of XR-C1 is complemented by human chromosome 8) was made to determine, indirectly, the involvement of homology-directed recombination in DSB repair. RESULTS: The observed frequencies of aberrations per human chromosome 8 were not significantly different between cells containing one or two copies of this chromosome. The frequency of chromatid-type aberrations was doubled in XR-C1 cells compared with CHO-9 and XR-C1#8 cells. CONCLUSIONS: In hamster cells, recombination between homologous chromosomes appears not to have a major role in the formation of radiation-induced chromosomal aberrations, while nonhomologous repair seems to be important in both the G and G2 phases of the cell cycle.

Analysis of chromosome segregation by means of fluorescence in situ hybridization: application to cytokinesis-blocked human lymphocytes.

The application of methods based on in situ hybridization to centromeric regions to cytokinesis-blocked cells provides a convenient way for the analysis of chromosome segregation in interphase cells. In this way, the reciprocal segregation patterns in daughter nuclei can be visualized and most of the problems related to the artefactual loss or gain of chromosomes which flaw other methods are avoided. In this work, the methodology has been applied to human lymphocytes to investigate the influence of donor age on spontaneous malsegregation rates, the occurrence of multiple malsegregation events, and the effect of the cytokinesis-blocking agent cytochalasin B (Cyt B) on spontaneous and induced chromosome malsegregation. The results obtained with 14 male donors, aged 22-57 years, demonstrated a significant (p < 0.001) increase in the frequency of micronuclei and X chromosome missegregation (both non-disjunction and chromosome loss) with the increasing age of the donors. Moreover, a similar association was observed with cultures hybridized with either chromosome 8 or 18 centromere probes, suggesting that the age-related loss of fidelity in chromosome segregation in vitro may be a general trait. The investigation of the distribution of multiple malsegregation events in cultured lymphocytes of eight male and nine female donors, with the simultaneous hybridization with pairs of centromeric probes (for chromosomes X and 8 or X and 18), demonstrated a large excess of multiple events with respect to that expected by random segregation. This fact may highlight the existence of cellular subpopulation(s) prone to malsegregate, or indicate that the malsegregation of one chromosome is able to affect the fidelity of segregation of the other chromosomes. Finally, the possible influence of Cyt B on chemically induced malsegregation has been investigated with the analysis of chromosomes X and 8 signals in nuclei of lymphocyte cultures treated with vinblastine (2.5-20 ng/ml) in the presence and absence of 6 micrograms/ml Cyt B. Vinblastine induced a small increase in hyperploidy of either chromosome X or 8 at 10 ng/ml in cultures treated with Cyt B. Without Cyt B, a significant increase of hyperploidy was only observed at the highest dose assayed (20 ng/ml). This vinblastine dosage had a severe inhibitory effect on cultures treated with Cyt B, where no binucleated cells were detected. At all doses, a relatively greater mitotic index was observed in cultures with Cyt B, suggesting a synergistic effect of this drug with vinblastine. Most notably, at the two highest vinblastine dosages (10 and 20 ng/ml), a large incidence of polyploid nuclei was observed in cytokinesis-blocked cultures, whereas none or far lower increases of polyploidy were found in the absence or Cyt. B. This results provides direct evidence of the potential of Cyt B to indirectly interfere with chromosome misdistribution induced by a spindle poison, to be considered before drawing firm conclusions from kinesis-blocked systems.