Epidural haematoma after evacuation of contralateral subdural haematoma

Background Sequentially evolving intracranial bilateral haematomas, where the second haematoma develops after the surgical removal of the first one is rarely reported. Aim To report a patient who developed an epidural haematoma after evacuation of a contralateral subdural haematoma. Methods A 49-year-old male was admitted to our department after head injury. A brain computerized tomography (CT) scan revealed an acute subdural haematoma in the right temporal area which was evacuated. During his stay in the intensive care unit, he was submitted to intracranial pressure monitoring, which soon rose. Results A new CT scan showed an acute epidural haematoma in the contralateral parietal area that was also evacuated. Conclusions While rising intracranial pressure after the evacuation of a traumatic haematoma is usually attributed to brain oedema or recurrent haematoma at the craniotomy site, the development of a contralateral epidural haematoma requiring surgical treatment should not be overlooked.     

Odontoblast dysfunction in osteogenesis imperfecta: an LM,SEM, and ultrastructural study

The inherited dentin defect dentinogenesis imperfecta (DI), while clinically obvious in osteogenesis imperfecta (OI) Types IB and IC, II, III, and IVB, is now thought to be present in all children with OI, in a continuum from minimal to severe dentin pathology. This collaborative study further clarifies the structural and ultrastructural dentin changes in the teeth of OI children with clinically obvious DI, and attempts to explain these in terms of odontoblast dysfunction. Collaborative studies were carried out in Melbourne, Australia, and Strasbourg, France, using light and polarized-light microscopy, scanning and transmission electron microscopy (SEM, TEM), selected-area diffraction (SAD), and x-ray spectroscopy (EDX). These showed structurally normal enamel (but containing long and broad lamellae) and a normally scalloped dentino-enamel junction (DEJ), but severe pathologic changes in the dentin. An initial narrow band of normal-appearing dentin tubules (including the mantle layer) ceased abruptly and was replaced by a wavelike laminar zone parallel to the DEJ with occluded tubules. Multiple parallel channels of 5-10 microns diameter were present at right angles to the DEJ indenting this zone, some terminating in retro-curved "processes." The abnormal dentin containing these channels almost completely occluded the pulp chamber. The structural and ultrastructural changes seen can be explained on the basis of the collagen defect in OI resulting in odontoblast dysfunction, which produces a distinct phenotype and one that is different from that in bone.     

Behavioural factors as predictors of motor vehicle crashes: differentials between young urban and rural drivers

OBJECTIVE: To describe the driver and behavioural factors that predispose young drivers to crash in the first 12 months of driving and to compare whether these factors differ between young urban and rural drivers. METHODS: A cohort comprising 1,796 newly licensed urban and rural drivers from Western Australia was recruited and followed over the first 12 months of driving. Using Cox proportional hazard analysis, driver and behavioural factors were assessed to determine whether they predicted the likelihood of a crash. RESULTS: The incidence rate for a motor vehicle crash was marginally higher for urban drivers compared with rural drivers (Urban: IR=4.2/10,000 driving days; Rural: IR=3.7/10,000 driving days). There was no significant difference in the time to crash between urban and rural drivers. Two factors, namely the frequency of driving before obtaining a learner-driver permit and the driver's level of risk taking, were significantly associated with a motor vehicle crash in the first year of driving. CONCLUSION: Irrespective of whether the driver is licensed in a rural or urban area, high risk-taking drivers are at an elevated risk of a motor vehicle crash in the first 12 months of driving. IMPLICATIONS: Aspects of Graduated Driver Training and Licensing Programs (GDTLP) could be effective in targeting this at-risk group.     

Synthesis, biological evaluation, and pharmacophore generation of uracil, 4(3H)-pyrimidinone, and uridine derivatives as potent and selective inhibitors of parainfluenza 1 (Sendai) virus.

Several new 6-oxiranyl-, 6-oxiranylmethyluracils, and pyrimidinone derivatives, synthesized by lithiation-alkylation sequence of 1,3,6-trimethyluracil, 1,3-dimethyl-6-chloromethyluracil, and 2-alkoxy-6-methyl-4(3H)-pyrimidinones, showed a potent and selective antiviral activity against Sendai virus (SV) replication. To gain insight into the structural features required for SV inhibition activity, the new compounds were submitted to a pharmacophore generation procedure using the program Catalyst. The resulting pharmacophore model showed high correlation and predictive power. It also rationalized the relationships between structural properties and biological data of these inhibitors of SV replication.     

Comparison of electrode position in the human cochlea using various perimodiolar electrode arrays

OBJECTIVE: This study was conducted to evaluate the insertion properties and intracochlear trajectories of three perimodiolar electrode array designs and to compare these designs with the standard Cochlear/Melbourne array. BACKGROUND: Advantages to be expected of a perimodiolar electrode array include both a reduction in stimulus thresholds and an increase in dynamic range, resulting in a more localized stimulation pattern of the spiral ganglion cells, reduced power consumption, and, therefore, longer speech processor battery life. METHODS: The test arrays were implanted into human temporal bones. Image analysis was performed on a radiograph taken after the insertion. The cochleas were then histologically processed with the electrode array in situ, and the resulting sections were subsequently assessed for position of the electrode array as well as insertion-related intracochlear damage. RESULTS: All perimodiolar electrode arrays were inserted deeper and showed trajectories that were generally closer to the modiolus compared with the standard electrode array. However, although the precurved array designs did not show significant insertion trauma, the method of insertion needed improvement. After insertion of the straight electrode array with positioner, signs of severe insertion trauma in the majority of implanted cochleas were found. CONCLUSIONS: Although it was possible to position the electrode arrays close to the modiolus, none of the three perimodiolar designs investigated fulfilled satisfactorily all three criteria of being easy, safe, and atraumatic to implant.     

The double puncture: an effective percutaneous technique for removing complex, multiple renal calculi

Percutaneous nephrostolithotomy, which can require a double puncture, is presently the method of choice in our institution for the removal of renal stones. Patients that underwent this procedure were evaluated to identify the possible reasons for the double puncture. Of 200 patients evaluated, 14 needed a second tract. The three variables that determined whether a second puncture was needed, in order of importance, were number and size of the stones, with second tracts needed in patients with multiple stones and staghorn calculi; anatomical variations of the renal collecting system itself, with bifid systems the most significant anatomic variation; and the dexterity of the radiologist in performing the puncture and the ability of the urologist to extract the stone. Second tracts were needed more frequently in patients who presented with stones in both the lower and middle poles of the collecting systems.