Biomedical subjects
Publications and source records attributed to N Sans.
Ultrasound exploration of the thorax is a very useful imaging method in children. For adults, it is useful for pleural effusion, study of the diaphragm and to guide percutaneous puncture of targeted pleuro-parietal, mediastinal or peripheral parenchymal sites. Thoracic ultrasound remains underused, particularly as a bedside exploration technique or in emergency or intensive care situations.
PURPOSE: We studied 11 healthy subjects were evaluated using cine MR imaging comparing HASTE and gradient echo sequences. Materials and methods :HASTE is a high-speed turbo-spin echo T2-weighted sequence. All examinations were performed using dynamic MRI using a simple process allowing acquisition of images at different stages during flexion and extension. The cine MR evaluation was obtained by rebuilding a cine-loop sequence. RESULTS: HASTE sequence provides a myelographic effect of the cervical spine. The size, the pattern and the movements of the cervical spine, the spinal cord, as well as the functional reserve of cerebro-spinal fluid are analysable. CONCLUSION: Because of its very high speed, HASTE sequence is particularly useful for cine MR imaging.
The epidural space which extends along the spine, surrounds the dural sac and is bounded by the bony and ligamentous structures of the vertebral canal. The knowledge of the anatomy of this region is important because the high frequency of the pathological processes in this area (tumoral, infections, vascular). The purpose of this presentation is to present the normal radio-anatomy of the lumbar epidural space and then the main pathological processes of this region.
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The aim of this study was to investigate the potential plasticity of the vestibular system, in structural and biochemical terms, at the level of the gravity receptors (the sensory hair cells), the primary neurons relaying the sensory signals (the vestibular ganglion neurons) and their projections into the vestibular nuclei. We studied the biochemical differentiation of the sensory cells and of the vestibular ganglion by investigating which calcium-binding proteins were present. We studied the development of peripheral synaptic connections of the efferent system by investigating the distribution of CGRP (calcitonin-gene related-peptide) and we also studied the cerebellar synaptic connections in the vestibular nuclei, as identified by the presence of calbindin. Putative changes were studied after a 17-day episode of microgravity (Neurolab STS-90), in developing rats between postnatal days 8 and 25. The extent to which these changes could be caused by alterations in gravity was determined by examining sensory and nervous structures not involved in gravity detection, the cochlea and the cochlear nuclei.
The aim of this study was to assess if a liver capsular retraction is a specific CT sign in malignant hepatic tumors. The authors reviewed retrospectively 320 hepatic CT scans obtained in 300 patients during a 3-year period. These patients presented with benign (n = 64) or malignant (n = 236) hepatic tumors. In 7 patients we found retraction of the capsule surrounding the tumor. All these tumors were histologically proven as malignant lesions: 4 metastases (none being chemically treated), 2 peripheral cholangiocarcinomas, and 1 epithelioid hemangioendothelioma. The prevalence of this sign was 2.18% (7 of 320) in this series. This capsular retraction pattern has never been found in hepato-cellular carcinomas (no fibrolamellar in this series) and benign lesions. Liver capsular retraction is an uncommon but specific (100%) sign in malignant hepatic tumors; however, a larger and prospective series is needed.
AIM OF THE STUDY: To describe a technique of percutaneous CT guided catheter drainage of infected pancreatic necrosis and to report the results of this technique compared with those of the conventional surgical treatment and of other percutaneous drainage series. PATIENTS AND METHODS: Between 1992 and 1997, the series included 32 patients who had a severe acute necrotizing pancreatitis with a mean Ranson score of 4.6, scored into grade D (n = 10), and grade E (n = 22), according to the Balthazar radiological staging. Modified Van Sonnenberg 24 F double lumen catheters were used for continuous irrigation and aspiration. RESULTS: Forty-nine drains were inserted for 41 infected necroses and eight abscesses. Among the 32 patients, the proof of infected necrosis was obtained in 26 patients by fine needle aspiration and culture (enterococcus, staphylococcus, pseudomonas). The average delay of catheter insertion was 23 days after onset of pancreatitis; the mean duration of drainage was 43 days, and an average of three catheters per patient was required. Five patients (15%) died, and among the survivors, 16 (59%) presented 21 complications including 14 enterocutaneous or pancreatic fistulas. A subsequent surgical procedure including two necrosectomies was necessary in six patients. CONCLUSION: This study demonstrates that percutaneous drainage of infected pancreatic necrosis with a 15% mortality and 70% success rate, represents an interesting alternative to conventional surgery.
The neuromodulator gamma-hydroxybutyrate is synthesized in vivo from gamma-aminobutyrate by transamination to succinic semialdehyde and subsequent reduction of the aldehyde group. In human brain, succinic semialdehyde reductase is thought to be responsible for the conversion of succinic semialdehyde to gamma-hydroxybutyrate. In the present work, we cloned the cDNA coding for succinic semialdehyde reductase and expressed it in Escherichia coli. A data bank search indicated that the enzyme is identical with aflatoxin B1-aldehyde reductase, an enzyme implicated in the detoxification of xenobiotic carbonyl compounds. Structurally, succinic semialdehyde reductase thus belongs to the aldo-keto reductase superfamily. The recombinant protein was indistinguishable from native human brain succinic semialdehyde reductase by SDS/PAGE. In addition to succinic semialdehyde, it readily catalyzed the reduction 9,10-phenanthrene quinone, phenylglyoxal and 4-nitrobenzaldehyde, typical substrates of aflatoxin B1 aldehyde reductase. The results suggest multiple functions of succinic semialdehyde reductase/aflatoxin B1 aldehyde reductase in the biosynthesis of gamma-hydroxybutyrate and the detoxification of xenobiotic carbonyl compounds, respectively.
PURPOSE: To reevaluate at medium term the results of computed tomography (CT)-guided percutaneous resection of osteoid osteomas. MATERIALS AND METHODS: Thirty-eight patients who had undergone treatment by means of this technique were reexamined with a mean follow-up of 3.7 years. The short- and medium-term clinical course and histologic features of the resection specimens were analyzed. RESULTS: The bone fragment could be analyzed in all cases, and the diagnosis of osteoid osteoma was confirmed in 28 patients (74%). A different diagnosis was made in six patients: mucoid cyst, subchondral arthritic geode, fibrous dysplastic lesion, focal osteochondritis, or focal chronic osteomyelitis. Cure was obtained in 32 patients (84%), whatever the cause. Complications, generally minor and transient, were observed in nine patients (24%). The most severe complications were two femoral fractures and one focal chronic osteomyelitis due to Staphylococcus aureus infection. CONCLUSION: The results of this study confirm the efficacy of percutaneous resection of osteoid osteomas and the possibility of using this method for successful treatment of other small bone lesions.
Gorham disease, or massive osteolysis, generally presents as osteolysis of a girdle bone. We report the case of a young adult who presented a fracture followed by destruction of the third right rib, then by regrowth eight months later.
The lateral view of the chest is a complementary incidence performed less frequently nowadays with the great frequency of chest CT. In fact, this lateral radiograph has important potential and can even give some exclusive information. With the 3-dimensional visualization provided by CT, the lateral radiograph of the chest is even easier to understand. Following in the footsteps of our great predecessors (Felson, Heitzman, Proto) we propose the left lateral view and offer our opinion about indications, techniques and results. The left lateral view can be performed with perfect perpendicular orientation or with a slight lateral shift that can be chosen with the right shoulder forwards (shifted right anterior lateral) or the contrary (shifted left anterior lateral). The left lateral view, like the antero-posterior view must be interpreted in a circular-concentric fashion.
Snapping scapula is a rare and poorly known cause of shoulder pain and is related to mechanical impingement between the scapula and the rib cage. We present a case in which CT scan was valuable, as a complement to clinical evaluation, for demonstrating the bony component of this entity. 3D reconstructions greatly facilitated diagnosis.
PURPOSE: To evaluate the mid-term outcome following CT-guided percutaneous resection of osteoid osteoma. MATERIALS AND METHODS: 38 patients who had been treated by CT-guided percutaneous resection were included. The mean follow-up of 3.7 years. Early and mid-term outcome and histology were analyzed. RESULTS: Histological samples were adequate in 92% of cases and a diagnosis of osteoid osteoma was confirmed in 73.7% of cases. In 6 cases, the lesion was not an osteoid osteoma: 2 mucoid cysts, 1 benign fibrous dysplasia, 1 fibromucoid lesion, 1 focal osteochondritis, 1 osteomyelitis. Cure was achieved in 84.2% of patients. Minor transient complications occurred in 23.7% of cases. The most serious complications included: 1 intramuscular hematoma, 2 femoral fractures, and 1 case of S. aureus osteomyelitis. CONCLUSION: This study confirms that CT-guided percutaneous resection of osteoid osteomas is effective and shows that other small lesions can also be treated using this technique.
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The authors report 2 cases of congenital mesothelial cyst of the diaphragm diagnosed in adults. The differential diagnosis will be discussed and the literature reviewed.
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