Endogenous nitric oxide (NO) has antimycobacterial properties. We tested the hypothesis that exogenous (inhaled) NO can be safely delivered and can accelerate airway disinfection for pulmonary tuberculosis patients treated with standard therapy. Exogenous NO administered at 80 ppm for 72 h can be safely delivered but does not accelerate airway disinfection.

Background: Temporal lobectomy in adults is an accepted form of treatment for patients with intractable complex partial seizures. There have been few long-term studies of children undergoing temporal lobectomy for epilepsy. Methods: We reviewed the pediatric cases of temporal lobectomy for intractable epilepsy performed by the Comprehensive Epilepsy Program at the University of Alberta Hospitals between 1988 and 2000. All patients had preoperative and postoperative clinical evaluations, seizure charts, drug levels, EEG, CT/MRI, long-term video EEG monitoring and neuropsychological testing. The patients were reassessed at 6 weeks, 6 months and 1 year postoperatively, then yearly. The duration of follow up was 1–10 years (mean 5 years). Results: Forty-two patients were studied (25 males and 17 females). Age at surgery ranged from 18 months to 16 years. The interictal EEG was abnormal in 38 of the 42 patients. Twenty-two patients had focal epileptic discharge and 1 had generalized epileptic discharge. Focal slowing was seen in 9 patients and diffuse slowing in 5 patients. CT scan was abnormal in 17 of 39 patients and normal in 22 of 39. MRI was abnormal in 34 of 42 patients and normal in 8 of 42. Pathology included brain tumors in 14 patients, mesial temporal sclerosis in 8, focal cortical dysplasia in 4, tuberous sclerosis in 4, dual pathology in 4, porencephalic cyst in 1 and normal pathology or gliosis in 6. Thirty-three of 42 patients (78%) were seizure-free following surgery and an additional 5 (12%) had a decrease in seizure frequency. Three patients had complications, but there were no deaths. Conclusion: Temporal lobectomy is a safe and effective treatment for children with intractable complex partial seizures. Seventy-eight percent of patients are seizure-free following the surgery and there are few complications. MRI is superior to CT scan for detection of temporal lobe pathology yet failed to detect abnormalities in some patients. The most common pathologies found were brain tumors, mesial temporal sclerosis and developmental lesions. In addition to seizure control, many patients experienced improvement in cognitive and psychosocial function following surgery.

Epilepsy surgery is considered a treatment option for patients with intractable seizures. Relatively few studies of efficacy, safety, and long-term outcome are available for the pediatric age group. This study describes a 12-year experience with pediatric epilepsy surgery at the University of Alberta. Records of pediatric epilepsy surgery patients admitted to the Comprehensive Epilepsy Program at the University of Alberta between 1988 and 2000 were reviewed. All patients received preoperative and postoperative clinical evaluation, seizure charts, testing of drug levels, electroencephalogram, computed tomography/magnetic resonance imaging, neuropsychologic testing, and long-term video electroencephalogram monitoring. The patients were reassessed after surgery at 6 weeks, 6 months, and 1 year and then yearly. The duration of follow-up was 1 year to 12 years. Forty-two patients underwent temporal lobectomies; 35, extratemporal resection. The age at surgery ranged from 6 months to 16 years. Thirty-two (76%) of temporal lobe patients became seizure-free (Engel Class I) vs 24 (68%) for the extratemporal group (Engel Class I). One patient (2%) in the temporal group had an Engel Class II outcome and one patient (3%) in the extratemporal group had the same Engel Class II outcome. Three patients (4%) manifested postoperative complications, and there were no deaths. Patients reported improvement in cognitive abilities, behavior, and quality of life after the surgery. Epilepsy surgery in children is effective and safe. Many children are seizure-free after the operation and remain so, although the results of temporal lobectomy are better than for extratemporal resections. There are few complications, and children often have an improved quality of life.

Deposition of a polydisperse aerosol (MR/ID = 4.8 mu m, GSD = 1.65) in a replica of a human mouth-throat is measured experimentally and compared to predicted results using computational fluid dynamics (CFD). The mouth-throat geometry represents an idealized, average mouth-throat. Experimental values of the fraction eta of aerosol depositing in this mouth-throat are obtained using a radiolabelled, nebulized aerosol generated with a Pari LC+ nebulizer. Gamma scintigraphy is used to measure amounts of aerosol depositing at laminar (21 min(-1)) and turbulent (28.31 min(-1)) flow rates. Deposition is predicted computationally using a commercial CFD code (TASCflow) for these two flow rates. For the turbulent case, the standard k-epsilon turbulence model was used with the most common eddy lifetime model for turbulent particle dispersion [Gosman and Ioannides (1983) J. Energy 7, 482-490].Good agreement between experiment and simulation is found for laminar flow (experiment: eta = 15.7 +/- 0.3%, simulation eta = 16%), but not for turbulent flow (experiment: eta = 25.6 +/- 0.7%, simulation eta = 65%). Measured and predicted pressure drops agree well for laminar flow (experiment: 0.26 +/- 0.02 Pa, simulation: 0.25 Pa), but differ less dramatically for the turbulent case than does deposition (experiment: 25.2 +/- 0.5 Pa, simulation: 22.3 Pa), indicating that accurate prediction of particle deposition in this geometry requires more accurate prediction of the fluid dynamics than can be obtained with the present turbulence model (C) 2000 Elsevier Science Ltd. All rights reserved.

To develop theoretical deposition models, assumptions are introduced to make the models computationally affordable. For this reason, experimental (in vivo) validation of such models is needed to give confidence to the assumptions being made. However, for an in vivo deposition experiment to be considered useful for validation of a model, a number of parameters must be measured in the experiment for input to the model. Ideally, these parameters would include time-dependent breathing flow rates during aerosol exposure, properties of the inhaled aerosol as a function of time during the breath (including particle size distribution, aerosol mass fraction, as well as hygroscopic properties, inhaled temperature and humidity if hygroscopicity is important), in addition to anatomical regional deposition data and detailed lung geometry measurements. Furthermore, because of the dependence of extrathoracic filtering on the inlet conditions at the mouth and the complexity of modeling deposition in this region, experimental data on the filtering properties of the mouth-throat are needed. Although some of the above parameters are impractical to measure with current experimental techniques, it would greatly aid the development of deposition models if as many of these parameters as possible were measured in future in vivo deposition experiments. Data exemplifying the importance of measuring the above parameters is discussed.

BACKGROUND There have been few prospective studies regarding the investigation of biliary strictures, principally because of rapid technological change. The present study was designed to determine the sensitivity of various imaging studies for the detection of biliary strictures. Serum biochemistry and imaging studies were evaluated for their role in distinguishing benign from malignant strictures. METHODS Thirty-one patients with suspected noncalculus biliary obstruction were enrolled consecutively in the study. A complete biochemical profile, ultrasound, Disida scan and cholangiogram (endoscopic retrograde cholangiopancreatography [ERCP] or percutaneous cholangiogram) were obtained at study entry. Stricture etiology was determined based on cytology, biopsy and/or clinical follow-up at one year. RESULTS Twenty-nine of 31 patients had biliary strictures, of which 15 were malignant. The mean age of the malignant cohort was 73.9 years versus 53.9 years in the benign cohort (P<0.001). Statistically significant differences between the malignant and benign groups, respectively, were as follows: alanine transaminase 235.2 versus 66.9 U/L (P=0.004), aspartate transaminase 189.8 versus 84.5 U/L (P=0.011), alkaline phosphatase 840.2 versus 361.1 U/L (P=0.002), bilirubin 317.8 versus 22.1 micromol/L (P<0. 001) and bile acids 242.5 versus 73.2 micromol/L (P=0.001). Threshold analysis using receiver operative characteristic (ROC) curves demonstrated that a bilirubin level of 75 micromol/L was most predictive of malignant strictures. Intrahepatic duct dilation was present in 93% of malignant strictures versus 36% of benign strictures (P=0.002). Common hepatic duct dilation was less discriminatory (malignant 13.5 versus benign 9.6 mm; P=0.11). Ultrasound was highly sensitive (93%) in the detection of the primary tumour in the bile duct or pancreas, or in the visualization of nodal or liver metastases. In benign disease, ultrasound failed to detect evidence of intrahepatic or extrahepatic biliary dilation in most cases. Disida scans were not able to distinguish between malignant or benign strictures and could not accurately localize the level of obstruction. The sensitivity of Disida scan for the diagnosis of obstruction was 50%. Cholangiographic characterization of strictures revealed an equal distribution of smooth (eight of 13) and irregular (five of 13) strictures in the malignant group. Ten of 13 benign strictures were characterized as smooth. Malignant strictures were significantly longer than benign ones - 30.3 versus 9.2 mm (P=0.001). Threshold analysis using ROC curves showed that strictures greater than or equal to 14 mm were predictive of malignancy (sensitivity 78%, specificity 75%, log odds ratio 11.23). CONCLUSIONS A serum bilirubin level of 75 micromol/L or higher, or a stricture length of greater than 14 mm was highly predictive of malignancy in patients with a biliary stricture. Ultrasound was useful in predicting malignant strictures by detecting either intrahepatic duct dilation or by visualizing the tumour (primary or metastases). Strictures with a 'benign' cholangiographic appearance are frequently malignant. Disida scan did not add additional information. ERCP is necessary to diagnose benign strictures, which tend to be less extensive at presentation.