Human eosinophil major basic protein augments bronchoconstriction induced by intravenous agonists in guinea pigs

The direct effect of intratracheal (IT) administration of human major basic protein (MBP) on pulmonary inspiratory pressure (PIP), and the effect on agonist-induced change in PIP, were determined in anesthetized, ventilated guinea pigs. 500 g MBP increased PIP from 24.1±4.3 to 49.8±7.4 cm H₂O (p<>n=10). Maximum PIP was achieved within 30 min after 500 g MBP. The direct PIP response to 250 g MBP was not different from vehicle. The PIP responses to intravenous (IV) acetylcholine (Ach) and 5-hydroxytryptamine (5-HT) were measured before and after administration of 250 g MBP (n=12). MBP caused a modest, but significant potentiation of the increase in PIP induced by 1, 3 and 10 g/kg Ach (24, 32 and 28%, respectively,p<0.02) and=" to=" 1=">g/kg 5-HT (43%p<0.02). we=" conclude=" that=" mbp=" at=" a=" dose=" that=" does=" not=" directly=" affect=" inspiratory=" pressure=" is=" capable=" of=" augmenting=" the=" pip=" response=" to=" iv=" ach=" and=">in vivo.     

Seizures and civilian head injuries

Although several studies have reported on the risk of "early seizures" (seizures occurring within 7 days following a head injury), the reported proportions of patients experiencing these seizures vary from 1.4 to 15%. This wide divergence may be due to problems with methodology such as case selection and definitions of head injury and early seizures. In a series of 702 patients admitted with a head injury to Cook County Hospital (CCH), Chicago, Illinois, 29 (4.1%) had early seizures. This proportion is twice as high as one previously reported in a comparable series. This may reflect an actual difference between the two series or a case selection bias serving to elevate the proportion of patients with early seizures at CCH.     

Evaluation of patients undergoing lung volume reduction surgery: ancillary information available from computed tomography

AIM: A number of imaging techniques have been used for the pre-operative assessment of patients for lung volume reduction surgery (LVRS). We evaluated whether data currently acquired from perfusion scintigrams and cine MR of the diaphragm are obtainable from high resolution CT (HRCT) of the thorax. MATERIALS AND METHODS: Thirty patients taking part in a randomized controlled trial of LVRS against maximal medical therapy were evaluated. HRCT examinations (n= 30) were scored for (i) the extent and distribution of emphysema; (ii) the extent of normal pulmonary vasculature; and (iii) diaphragmatic contour, apparent defects and herniation. On scintigraphy, (n= 28), perfusion of the lower thirds of both lungs, as a proportion of total lung perfusion (LZ/T(PERF)), was expressed as a percentage of predicted values (derived from 10 normal control subjects). On cine MR (n= 25) hemidiaphragmatic excursion and coordination were recorded. RESULTS: Extensive emphysema was present on HRCT (60% +/- 13.2%). There was strong correlation between the extent of normal pulmonary vasculature on HRCT and on perfusion scanning (r(s)= 0.85, P< 0.00005). Hemidiaphragmatic incoordination on MR was weakly associated with hemidiaphragmatic eventration on HRCT (P= 0.04). CONCLUSION: The strong correlation between lung perfusion assessed by HRCT and lung perfusion on scintigraphy suggests that perfusion scintigraphy is superfluous in the pre-operative evaluation of patients with emphysema for LVRS.     

Radiographic findings in tuberculosis of the calvarium

We reviewed the pattern of involvement of the calvarium by tuberculosis (TB) in five patients and the role of imaging in its management. Four patients presented with localised scalp swelling and one with generalized seizures. Radiographs revealed lucent lesions with minimal surrounding sclerosis in the frontal (2), parietal (2) and occipital (1) bones. CT showed lesions involving the entire thickness of the calvarium and accompanying contrast-enhancing soft tissue. The patient presenting with seizures had a ring-enhancing lesion in the parietal lobe in addition to the extra-axial lesions. Although radiographs in all cases demonstrated calvarial TB, CT showed the extent of the defect, involvement of adjacent soft tissues, and in one case an intra-axial lesion. Radiographs suffice for follow-up of these patients. Received: 23 July 1999 Accepted: 20 September 1999     

Effects of tracheostomies on infection and airway complications in pediatric burn patients

Considerable controversy exists as to whether tracheostomy is ever indicated in burn patients. New advents in the treatment of inhalation injury have improved survival, making the use of tracheostomy more usual. The purpose of this study was to analyze the outcome of tracheostomies, and the effect of time on complications. Patients requiring ventilatory support and tracheostomies were studied. Demographic data, hospital course, ventilatory parameters and complications were analyzed. Two hundred ninety patients required ventilation and 36 tracheostomy. Mean percentage of TBSA burned was 59%+/-4. Ninety percent of these patients presented with inhalation injury. Mortality in tracheostomy patients was 25 and 16% in all ventilated patients. Thirty-five percent of the patients developed late complications. Patients who had their airway converted to tracheostomy before day 10 postinjury had a significantly lower incidence of subglottic stenosis. and patients who required airway pressures over 50 cm H2O for more than 10 days had a significantly higher incidence of tracheomalacia. Pneumonia occurred at similar incidence in ventilated and tracheostomy patients. The mortality and late complications of pediatric burn patients with tracheostomy has decreased over the last decade. They do not present with higher incidence of pneumonia. Maintenance of airway pressures below 50 cm H2O and conversion of the artificial airway to tracheostomy before day 10 postinjury may be advisable in patients requiring long term ventilation to prevent late complications.     

Contents Volume 32 No. 1 (2000) Section One: International Urology and Nephrology

Table of Contents

Contents Volume 32 No. 1 (2000) Section One: International Urology and Nephrology     

Percutaneous nephrolithotripsy in ectopic kidneys

BACKGROUND: Percutaneous nephrolithotomy (PCNL), although an accepted treatment modality in anatomically normal kidneys, is still not universally performed for calculi in pelvic ectopic kidneys. Fear of injury to abdominal viscera makes it a technically challenging procedure. PATIENTS AND METHODS: We have performed PCNL in nine patients with calculi in pelvic ectopic kidneys. Technical factors which made this procedure safe include ultrasound-guided puncture, use of a mature tract or an Amplatz sheath, routine postoperative double-J stenting, and nephrostogram prior to nephrostomy tube removal. RESULTS: Complete stone clearance was achieved in all cases. Six patients were treated in a single stage, while three patients required two stages. Seven patients needed only one tract, and two needed two tracts. No notable complications were encountered. The average hospital stay was 5.2 days. CONCLUSION: With proper precautions and meticulous technique, PCNL is a safe and effective modality to treat calculi in pelvic ectopic kidney.     

Unusual massive neurinoma in the suboccipital region--case report

An 8-year-old boy with no evidence of von Recklinghausen's disease presented with an unusual neurinoma manifesting as a gradually progressive swelling in the suboccipital region over 2 years. The lesion was massive and had widely eroded the posterior aspects of the atlas, axis, and suboccipital bone. The tumor had involved the dura of the sigmoid and transverse sinuses, was highly vascular, and had encased the ipsilateral vertebral artery. The tumor was almost completely resected although with considerable loss of blood through a large rent in the right sigmoid sinus. This unusual benign neurinoma most probably arose from the second cervical ganglion.     

Comparative mouse skin tumorigenicity and induction of Ha-ras mutations by bay region diol epoxides of 5-methylchrysene and 5,6- dimethylchrysene

We compared the tumor-initiating activities toward mouse skin of two structurally related polycyclic aromatic hydrocarbon diol epoxides: racemic anti-1,2,3,4-tetrahydro-5,6-dimethylchrysene-1,2-diol-3,4- epoxide (5,6-diMeCDE) and racemic anti-1,2,3,4-tetrahydro-5- methylchrysene-1,2-diol-3,4-epoxide (5-MeCDE). Tumors induced by these diol epoxides were analysed for mutations in the Ha-ras gene. 5,6- diMeCDE is derived from the non-planar parent compound 5,6- dimethylchrysene, and reacts to approximately equal extents with dA and dG in DNA, whereas 5-MeCDE is derived from a nearly planar parent compound, 5-methylchrysene, and reacts mainly with dG in DNA. 5,6- diMeCDE, at initiating doses of 33, 100 or 400 nmol per mouse, induced 1.2, 2.2 and 6.2 skin tumors per mouse, respectively. It was significantly less tumorigenic than 5-MeCDE which induced 3.1, 7.5 and 9.1 skin tumors per mouse at the same doses. Tumors induced by 5,6- diMeCDE had a large number of CAA-->CTA mutations in codon 61 of the Ha- ras gene: 50, 55 and 75% of the tumors analysed had this mutation at the 33, 100 and 400 nmol doses. No mutations were found in codons 12 and 13 in the tumors induced by 5,6-diMeCDE. In contrast, CAA-->CTA mutations in codon 61 were rarely seen in tumors induced by 5-MeCDE. At the highest dose of 5-MeCDE, 20% of the tumors analysed had mutations at G of codons 12 and 13. The results of this comparative study support the hypothesis that mutations in the Ha-ras gene in mouse skin tumors induced by PAH diol epoxides occur as a result of their direct reaction with the gene. However, pathways other than the commonly observed Ha- ras codon 61 mutations are clearly important in mouse skin tumorigenesis by these diol epoxides.      

Gradient correction and classification of CT lung images for the automated quantification of mosaic attenuation pattern

PURPOSE: The detection of density differences, or "mosaic attenuation pattern," on CT images may be difficult when the regional inhomogeneity of the density of the lung parenchyma is subtle. The purpose of this work was to develop a fully automated method for the reproducible quantification of the underattenuated areas of the lung parenchyma. This technique may be useful in increasing the precision of investigation of structure/function relationships. METHOD: Anatomical segmentation was achieved by a structure-filtering operator based on mathematical morphology. To compensate for the density gradient visible on lung CT scans, a model-based iterative deconvolution filter and an adaptive clustering algorithm were developed. Validation was performed with CT images from a lung phantom, 15 patients with constrictive obliterative bronchiolitis, and 8 normal subjects. RESULTS: The accuracy of the estimate of the density gradient on phantom studies was 93.3%. The automated quantification of the areas of decreased attenuation on scans of constrictive obliterative bronchiolitis was within 8.2% from the average scoring of two experienced observers. CONCLUSION: The proposed technique is fully automated and can accurately correct for density gradient and classify areas of decreased attenuation on lung CT images.