Mediastinal evaluation utilizing the reverse Trendelenburg radiograph

When thoracic aortic rupture is suspected, a 45-degree reverse Trendelenburg (RT) anteroposterior (AP) chest radiograph should place the mediastinal structures in a more appropriate position and allow a more accurate evaluation than a supine AP radiograph. One hundred ninety-one consecutive hemodynamically stable adult patients with major blunt thoracic trauma were initially evaluated for mediastinal abnormalities associated with aortic disruption by both supine AP chest radiograph and an AP chest radiograph with the patient in 45-degree RT position. One hundred four patients underwent contrast aortography based on mediastinal abnormalities detected on the supine AP chest radiograph. Twenty of these patients had abnormal aortograms demonstrating traumatic aortic disruption confirmed at surgery. Supine and RT chest radiographs were retrospectively compared in a blinded fashion to evaluate their specificity and positive predictive value for detection of traumatic thoracic aortic rupture. If RT chest radiographic findings had been used to determine the need for further assessment, 29 angiograms (26%) would have been eliminated, specificity would have increased from 52 per cent to 69 per cent, and positive predictive value would have increased from 19 per cent to 27 per cent. Both supine and RT chest radiographs demonstrated mediastinal widening in all 20 patients with abnormal aortograms, with no missed thoracic aortic disruptions (100% sensitivity). This study indicated that the RT chest radiograph may be used instead of the standard supine radiograph as the initial screen for mediastinal evaluation, maintaining a high sensitivity and eliminating the cost and morbidity of many unnecessary aortograms.     

MR imaging of human brain at 3.0 T: preliminary report on transverse relaxation rates and relation to estimated iron content

PURPOSE: To determine the transverse relaxation rates R2 and R2' from several gray matter regions and from frontal cortical white matter in healthy human brains in vivo and to determine the relationship between relaxation rates and iron concentration [Fe]. MATERIALS AND METHODS: Six healthy adults aged 19-42 years underwent thin-section gradient-echo sampling of free induction decay and echo magnetic resonance (MR) imaging at 3.0 T. Imaging covered the mesencephalon and basal ganglia. RESULTS: Relaxation rates (mean +/- SD) were highest in globus pallidus (R2 = 25.8 seconds-1 +/- 1.1, R2' = 12.0 seconds-1 +/- 2.1) and lowest in prefrontal cortex (R2 = 14.4 seconds-1 +/- 1.8, R2' = 3.4 seconds-1 +/- 1.1). Frontal white matter measurements were as follows: R2 = 18.0 seconds-1 +/- 1.2 and R2' = 3.9 seconds-1 +/- 1.2. For gray matter, both R2 and R2' showed a strong correlation (r = 0.92, P < .001 and r = 0.90, P < .001, respectively) with [Fe]. Although the slopes of the regression lines for R2' versus [Fe] and for R2 versus [Fe] were similar, the iron-independent component of R2' (2.2 seconds-1 +/- 0.6), the value when [Fe] = 0, was much less than that of R2 (12.7 seconds-1 +/- 0.7). CONCLUSION: The small iron-independent component R2', as compared with that of R2, is consistent with the hypothesis that R2' has higher iron-related specificity.     

Children with congenital pulmonary lymphangiectasia: after infancy

OBJECTIVE: The objective of this original report is to describe the characteristic chest imaging findings in children with primary congenital pulmonary lymphangiectasia who survive infancy. CONCLUSION: In children with primary congenital pulmonary lymphangiectasia, increased interstitial markings decrease over time and increased hyperinflation is associated with persistent patchy areas of ground-glass opacity.     

Microangiopathy of the brain and retina with hearing loss in a 50 year old woman: extending the spectrum of Susac's syndrome

A 50 year old woman presented with a subacute onset of vertigo and diplopia followed by an encephalopathy with confusion, spasticity, ataxia, myoclonus, and multiple branch retinal arteriolar occlusions and unilateral sensorineural deafness. Brain biopsy confirmed multiple microinfarcts with no vasculitis. After the procedure she had a right iliofemoral deep vein thrombosis and was found to be heterozygous for the factor V Leiden mutation. She was treated with anticoagulants and made a marked recovery with no relapses 6 months after presentation. This case extends the age range at which Susac's syndrome can present, and raises the possibility that the condition may be associated with abnormalities of coagulation.     

Trans-axillary first rib excision for thoracic outlet syndrome

AIM: Thoracic outlet syndrome (TOS) is a clinical diagnosis treatable by excision of the first rib. This study was undertaken to assess the alleviation of symptoms following trans-axillary rib excision in patients with a diagnosis of TOS suggested by a positive Elevated Arm Stress Test and, by inference, to estimate the prevalence of the syndrome. METHOD: A retrospective review of trans-axillary first rib excision was performed. No referrals were accepted from outwith the catchment area of our hospital. Post-operative symptomatic improvement was accepted as a confirmation of correct pre-operative diagnosis. RESULTS: Over six years, 52 rib resections were performed in 46 patients, mean age (+/- S.D.) 38.8 (+/- 10.6) years. The indications for surgery were principally neurological symptoms (n = 42 excisions), arterial compromise (n = 5) and venous compromise (n = 5). Symptoms had been present for a mean of 15.8 months prior to surgery. The median follow-up after surgery was 33 months. 42 patients (48 resections) showed immediate improvement in symptoms following surgery, although symptoms recurred in three patients (4 resections) between 6 and 8 months post-operatively. In the final two years of this study, 20 resections resulting in symptomatic improvement were performed, suggesting a prevalence for TOS of at least 10 per 100,000 per year. CONCLUSIONS: Thoracic outlet decompression was performed more frequently in this series than many previous reports, suggesting that TOS may be under-diagnosed.     

Specific inhibition of epidermal growth factor receptor tyrosine kinase by 4-anilinoquinazolines

Summary Since the mitogenic action of EGF is mediated by ligand-induced autophosphorylation of the EGF receptor (EGFR), and EGFR is commonly overexpressed in solid human tumours, inhibitors of receptor tyrosine kinase activity (RTK) could prove to be effective antitumour agents. Screening of a compound library using an EGF-RTK enzyme prepared from human tumour derived A431 cells identified a series of potent (IC₅₀<1µM) enzyme inhibitors. These inhibitors are quinazolines bearing a variety of substituted anilines at the 4-position. The most potent 4-anilinoquinazolines (IC₅₀ 20nM) have small non-polar meta substituents on the aniline ring, and are competitive with ATP and non-competitive with substrate. The growth inhibitory activity of these agents was assessed in vitro using KB cells (human oral squamous tumour) grown in the absence or presence of EGF. A selected compound, 4-(3-chloroanilino)quinazoline (CAQ), inhibited EGF-stimulated growth in a concentration dependent manner and complete blockade was observed at concentrations (1–10 µM) which had no effect on basal growth. Selectivity of growth inhibition by CAQ was further exemplified in IGF1-stimulated KB cells where no effect was detected at concentrations which completely blocked EGF-stimulated growth. Similarly, CAQ blocked TGF-stimulated growth in MCF-7 human breast cancer cells without affecting insulin-stimulated growth. These studies define a novel class of EGF-RTK inhibitors which are also potent and selective inhibitors of EGF-stimulated human tumour cell growthin vitro. Presented at the symposium "New Approaches in the Therapy of Breast Cancer", Georgetown University Medical Center, Washington DC, October 1994, generously supported by an education grant from Bristol-Myers Squibb.     

Analysis of faecal neutral sterols in patients with familial adenomatous polyposis by gas chromatography-mass spectrometry

Previous studies have suggested that patients with familial adenomatous polyposis (FAP) have increased faecal excretion of cholesterol but a reduction in cholesterol metabolites. It was consequently proposed that the degree of faecal cholesterol degradation could be used as a means of diagnosis. Developments in the extraction and analysis of faecal neutral sterols as well as the accurate means of diagnosing FAP by DNA analysis and indirect ophthalmoscopy has necessitated a re-examination of this proposal. Faecal neutral sterols were analysed in 10 patients with untreated FAP following a complete 5-day stool collection and compared with 9 healthy control subjects (including 4 siblings) closely matched for age and sex. The median [25 and 75, percentiles] stool wet weights were similar between the FAP (97.5 [69, 192] g · 24 h^-1) and the control (116 [61.5, 137] g · 24 h^-1) groups. Faecal cholesterol concentration was similar in the two groups (FAP=2.3 [1.4, 4.2]; control=3.5 [1.0, 6.0] mol · g^-1 dry wt) as was the concentration of total neutral sterols not including plant sterols (FAP=17.2 [13.4, 21.0]; control=18.2 [7.4, 21.6] mol · g^-1 dry wt). There were no significant differences in the proportions of cholesterol metabolised between the FAP (82.3 [74.2, 93.5]%) and control (72.1 [5.7, 81.3]%) groups. This study does not support the notion that faecal neutral sterol metabolism is uniquely different in patients with FAP.

---

Résumé Des études précedentes avaient suggéré que les malades avec polypose adénomateuse familiale (PAF) avaient une excrétion fécale augmentée de choléstérol mais une réduction des métabolìtes du choléstérol. On a donc proposé que les degrés de dégradation fécale du choléstérol puisse être utilisée comme moyen de diagnostic. Le développement dans l'extraction et l'analyse des stérols neutres fécaux aussi bien que des moyens appropriés de diagnostiquer la PAF par analyse du DNA et ophthalmoscopie indirecte a nécessité un ré-examen de cette proposition. Les stérols neutres fécaux, ont été analysés chez 10 patients avec une PAF non traitée après une collection complète des matières de 5 jours et comparés avec 9 sujets contrôles sains (comprenant 4 enfants de mêmes parents) étroitement appareillés pour l'âge et le sexe. Les poids moyens (25 et 75 percentiles) de selles humides étaient similaires chez les PAF (97.5 (69, 192) g · 24 h^-1) et les contrôles (116 (61.5, 137) g · 24 h^-1). La concentration de choléstérol fecal était similaire dans les deux groupes (PAF=2.3 (1.4, 4.2); controle=3.5 (1.0, 6.0) mol · g poids sec) de même que la concentration de stérols neutres totaux stéroïdes végétaux exclus (PAF=17.2 (13.4, 21.0); controle 18.2 (7.4, 21.6) mol · g poids sec). Il n'y avait pas de différence significative dans les proportions de choléstérol métabolisé entre les PAF (82.3 (74.2, 93.5)%) et les contrôles (72.1 (5.7, 81.3)%). Cette étude ne confirme pas la notion que le métabolisme des stérols neutres fécaux est uniquement différent chez les patients avec une PAF.