[Imaging features of neurologic and orthopedic complications from severe trauma]. / Imagerie des complications neuro-orthopédiques des traumatismes graves.

Cranial and spinal trauma are a frequent cause of disability in the general population. Post-traumatic paraplegia or quadriplegia or hemiplegia from vascular injury (CVA) can lead to early complications (respiratory, cardiovascular, urinary, cutaneous, infectious...) that may have an impact on the immediate prognosis. Neurologic and orthopedic complications occur later and further impair the quality of life of patients. Orthopedic complications include: neurogenic paraosteoarthropathy (NPOA) or neurogenic osteoma or myositis ossificans (NMO). The nomenclature currently in use is NMO; Osseous complications: osteoporosis and secondary insufficiency fractures; Joint complications: degenerative arthropathy and stiffness; Overuse mechanical complications; Muscular complications; Infectious complications: arthritis and myositis complicating skin ulcers and bed sores. The purpose of this paper is to describe these neuro-orthopedic complications and review their imaging features.

[Spasticity: clinical and imaging features]. / La spasticité: de la clinique à l'imagerie.

Spasticity, a component of the pyramidal syndrome, characterized by increased tonic stretch reflexes and hyperactive deep tendon reflexes, occurs in patients with central nervous system lesions (stroke, brain or cord injury, multiple sclerosis, cerebral motor impairment). The implementation of standard procedures (patient positioning, increased examination time, turning off certain devices before MR imaging) allows the acquisition of high quality examinations in spastic patients. Worsening spasticity in a handicaped patients is due to an irritative process (deep seated infection, fracture, syrinx...) usually detectable with imaging. Ultrasound or CT guided injections of botulinum agents provides radiologists with the opportunity to further participate in the management of spastic patients.

[Imaging features of post-traumatic spine and cord lesions]. / Imagerie des séquelles médullaires et rachidiennes post-traumatiques.

The imaging evaluation of post-traumatic spine and cord injuries is part of the global management of chronically handicapped patients. Diagnosis and follow-up MR imaging of cord lesions allows differentiation of static lesions from progressive lesions that could require surgical intervention. Follow-up CT imaging is helpful in the evaluation of spine lesions to distinguish between late complications (deformity, malunion, pseudoarthrosis, complications related to surgical hardware) and lesions secondary to the handicap (neurogenic spinal arthropathy).

Drosophila deoxyribonucleoside kinase mutants with enhanced ability to phosphorylate purine analogs.

Transduced deoxyribonucleoside kinases (dNK) can be used to kill recipient cells in combination with nucleoside prodrugs. The Drosophila melanogaster multisubstrate dNK (Dm-dNK) displays a superior turnover rate and has a great plasticity regarding its substrates. We used directed evolution to create Dm-dNK mutants with increased specificity for several nucleoside analogs (NAs) used as anticancer or antiviral drugs. Four mutants were characterized for the ability to sensitize Escherichia coli toward analogs and for their substrate specificity and kinetic parameters. The mutants had a reduced ability to phosphorylate pyrimidines, while the ability to phosphorylate purine analogs was relatively similar to the wild-type enzyme. We selected two mutants, for expression in the osteosarcoma 143B, the glioblastoma U-87M-G and the breast cancer MCF7 cell lines. The sensitivities of the transduced cell lines in the presence of the NAs fludarabine (F-AraA), cladribine (CdA), vidarabine and cytarabine were compared to the parental cell lines. The sensitivity of 143B cells was increased by 470-fold in the presence of CdA and of U-87M-G cells by 435-fold in the presence of F-AraA. We also show that a choice of the selection and screening system plays a crucial role when optimizing suicide genes by directed evolution.

Imaging findings in three cases of the nodular type of muscular sarcoidosis.

OBJECTIVE: Sarcoidosis is a granulomatous multisystem disorder that may uncommonly involve muscle. We report the sonographic and MRI findings in three cases of the nodular type of muscular sarcoidosis. CONCLUSION: Intramuscular hypoechoic well-defined nodules in young patients or patients with a history of sarcoidosis suggest the diagnosis of intramuscular sarcoid. MRI is useful in detecting muscle sarcoid, evaluating the extent and distribution of muscle involvement, and monitoring the patient during follow-up after steroid therapy. MRI showed nodules that were iso- or hyperintense relative to muscle on T1-weighted sequences. On T2-weighted images and STIR sequences, we observed numerous intramuscular nodules of homogeneous high signal intensity. All nodules enhanced homogeneously on contrast-enhanced T1-weighted sequences. Disappearance of all nodules was seen on follow-up sonograms and MR images after patients had received steroid therapy.

Proliferative myositis in a patient with AIDS.

We report a case of proliferative myositis in the right biceps of a 56-year-old man with acquired immune deficiency syndrome (AIDS). Imaging methods included sonography, computed tomography and magnetic resonance imaging. The diagnosis was made by a core-cut biopsy and fine needle aspiration biopsy with immunohistochemical analysis. The lesion disappeared after 2 months without treatment. It is particularly important to determine whether intramuscular masses arising in patients with AIDS are due to an infectious or malignant process.

[Value of MRI to evaluate extra-abdominal desmoid fibromatosis]. / Apport de l'IRM dans l'étude des fibromatoses desmoïdes extra-abdominales.

PURPOSE: To describe the MR appearance of extra-abdominal desmoid fibromatosis, especially using sequences such as MR angiography, STIR and FAT SAT. Materials and methods. We reviewed retrospectively the MRI studies of 8 patients (4 men and 4 women) with histologically proved desmoid fibromatosis. In five patients the lesion corresponded to recurrent disease. Eleven MRI examinations were available (Siemens, Vision, 1.5T) including the following sequences: pre- and postcontrast T1 weighted (11 cases), STIR (9 cases), and MRA (3 cases). All lesions were imaged in at least two orthogonal planes. CT was available for 5 patients. RESULTS: The lesions were localized to the girdles in 8 cases and to the upper extremity in 3 cases. Most lesions (10/11) were isointense to muscle on noncontrast T1W images and showed intense enhancement on postcontrast T1W images. All lesions (9/9) were hyperintense on STIR images. CONCLUSION: A STIR sequence is useful as a first sequence to identify smaller lesions (usually recurrences) and to better adapt the FOV of following sequences, especially before administration of intravenous contrast. MR angiography may be valuable for surgical planning.

[Bacterial cellulitis. Forms borderline between medical and surgical (3 cases)]. / Dermohypodermites bactériennes.

BACKGROUND: An acute infectious cellulitis may be managed medically (erysipelas or non-necrotizing infectious cellulitis) or surgically (necrotizing infectious cellulitis, necrotizing fasciitis). We report 3 cases of non-necrotizing infectious cellulitis borderline between medical and surgical forms, complicated by compartment syndrome, the surgical decompression of which permitted patients' cure. CASE REPORTS: Three patients, 27, 52 and 84 years old, were admitted for an acute infectious cellulitis of the leg. At admission, the leg area involved was erythematous, painful, indurated, with one or several bullae, purpura, pustules, hypoesthesia or limited skin necrosis, and no immediate need for surgical exploration. The clinical evolution was characterized by the slow appearance or extension of signs of severity, despite the modification in antibiotic treatment. Magnetic resonance imaging findings were indicative of a non-necrotizing infectious cellulitis in 2 patients. In one patient, necrotizing fasciitis could not be excluded. In all patients, surgical exploration showed an important quantity of non-purulent fluid between muscles and hypodermis, with no evidence of abscess or necrosis. A large incision rapidly cured all patients. DISCUSSION: These three observations were characterized by the initial signs of moderate severity and no response to an appropriate medical treatment, which led to surgical exploration. Surgery showed no abscess or necrosis but an important quantity of sterile fluid; it also permitted rapid cure of patients. These cases present a borderline form of infectious cellulitis, with severe local inflammation caused by a compartment syndrome. Surgical decompression was needed for cure. The potential value of magnetic resonance imaging in this situation should also be stressed.

[Calcific retropharyngeal tendinitis: unusual diagnosis]. / Tendinite calcifiante rétropharyngée: une lésion rare à évoquer.

Acute calcific retropharyngeal tendinitis is a rare entity that often is initially misdiagnosed a retropharyngeal abscess and treated with IV administration of antibiotics. In our 2 cases, imaging enabled a correct diagnosis to be made. Two patients were admitted to the hospital with dysphagia, severe neck discomfort and fever. Lateral radiographs of the cervical spine and CT were obtained in both cases, while MRI was obtained in one case. Calcification of the prevertebral muscles was demonstrated by CT in both cases, and detected on lateral radiographs in only one case. Soft tissue swelling was noted at CT and MRI. A clinical diagnosis of calcific retropharyngeal tendinitis may be difficult to achieve and a definitive diagnosis can be confirmed at imaging studies.

Cranial nerve palsy revealing an occipitovertebral metastasis from carcinoma of the uterine cervix.

A 37-year-old woman had a histologically documented occipitovertebral metastasis from an invasive epidermoid carcinoma of the uterine cervix. The metastasis was found 3 months after the primary and was treated by local radiation therapy followed by systemic chemotherapy. Radiation therapy was highly effective in relieving the pain but was not associated with changes in magnetic resonance imaging findings. Lymph node involvement and local extension occurred. The patient died 1 year after the diagnosis of the metastasis. Involvement of the occipitovertebral junction by uterine cervix carcinoma metastasis is exceedingly rare. The relevant literature is reviewed.

L5 radicular pain related to a cystic lesion of the posterior longitudinal ligament.

A 35-year-old man with a long history of left L5 radicular pain was found to have an intraspinal cystic lesion causing radicular compression. Magnetic resonance imaging demonstrated a round lesion situated in the anterior epidural space, with uniform high signal intensity on T2-weighted sequences characteristic of a cystic lesion. During surgery a liquid-containing cyst originating from the posterior longitudinal ligament was punctured and resected. The histologic aspect was that of a ganglion cyst without synovial layers. The radiologic differential diagnoses are discussed.

Topoisomerase I-mediated antiproliferative activity of enantiomerically pure fluorinated homocamptothecins.

Homocamptothecin (hCPT) is an E-ring modified camptothecin (CPT) analogue bearing a methylene spacer between the alcohol and carboxyl functions of the CPT lactone. Combining pronounced inhibitory activity of topoisomerase I (Topo I) with enhanced plasma stability, hCPT constitutes an attractive template for the elaboration of new anticancer agents. Fluorinated hCPT analogues, prepared in enantiomerically pure form, were assayed by their stimulation of Topo I-mediated DNA cleavage. Translation into cytotoxicity against tumor cells was evaluated on HT29 human colon adenocarcinoma and on the multidrug resistant lung and bladder tumor cell lines, A549 and T24r. Good correlation is observed between the ability of the drugs to stimulate Topo I-mediated DNA cleavage and the respective 50% inhibitory concentrations (IC(50) values) of the HT29, A549, and T24r cell growth. Fluorine substitution in the A-ring of hCPT was found to have a pronounced influence on biological activity, providing several compounds which are up to 100-fold more potent than CPT in terms of IC(50). Among these, 10,11-difluoro-hCPT has been selected for further development.

[Magnetic resonance angiography of the thorax in 2000]. / L'imagerie et l'angiographie par r¿esonance magn¿etique du thorax en l'an 2000.

Over the last five years, magnetic resonance imaging (MRI) has been the scene of explosive developments in many fields. MRI exploration of thoracic vessels, perfusion imaging of the pulmonary parenchyma, cine-MR, and apnea sequences have all seen impressive advances. This improvement has been made possible by progress in data processing and surface coil technology for a better signal-noise ratio. In 2000, indications for thoracic MRI remain limited due to the small number of machines available and the fact that the CT scan can provide superior quality images for the pulmonary parenchyma and for visualizing calcifications. MRI can be a complementary exam for lung cancer work-up in case of suspected invasion of the thoracic cavity or the mediastinum. It is the first intention exam in cases involving the greater vessels, with the exception of emergency situations, the posterior mediastinum, and the heart. We review here the current contribution of MRI in diseases of the chest and discuss perspectives for the future.

Utility of CT scan for the diagnosis of chest wall tuberculosis.

The objective of this study was to determine the utility of CT scan findings for the diagnosis of chest wall tuberculosis, excluding the spine. We reviewed 15 patients (13 Africans and 2 Indians) with chest wall tuberculosis, retrospectively. The radiologic examination consisted of a plain X-ray and a CT scan of the chest for each patient. The site of disease was the rib in 13 patients or the body of the sternum in 2 patients. One rib was involved in 11 patients, 2 contiguous ribs (one site) in 2 patients, and bilateral disease (two sites) was observed in the remaining patient. The 14 rib sites involved the posterior arc or costovertebral joint in 11 cases, the anterior arc in 2 cases, and the anterior and middle arc in 1 case. The CT scan findings were an abscess (n = 14) or a soft tissue mass (n = 2), osteolytic lesions (n = 13), periosteal reaction (n = 10), and sequestrum (n = 14). Bone sclerosis was observed only in 3 cases of rib involvement. The association of a soft tissue abscess, an osteolytic lesion, and sequestrum, especially in immigrants to France, suggests chest wall tuberculosis on CT scan.

Inhibition of human tumor cell growth in vitro and in vivo by a specific inhibitor of human farnesyltransferase: BIM-46068.

Oncogenic mutations of the ras gene leading to constitutive activation of downstream effectors have been detected in a large spectrum of human cancers (pancreas, thyroid, colon and NSCLC). Membrane anchorage of Ras required for functional activity in signal transduction is facilitated by post-translational modifications resulting in covalent attachment of a farnesyl group to the cysteine in the C-terminal CAAX motif. This attachment is mediated by farnesyltransferase (FTase). Here, we report a novel series of potent FTase inhibitors, where the tetrapeptide CAAX motif has been modified by incorporation of a thiazolidine carboxylic acid moiety followed by reduction of the 1st and 2nd peptide bonds to a secondary and tertiary amine, respectively. The C-terminal carboxylate was converted to esters for improved cellular penetration. These compounds showed specific inhibition of purified human FTase enzyme, inhibition of proliferation in vitro in a large spectrum of human tumor cell lines and inhibition of growth of human tumor xenografts in athymic nude mice. In addition, in regard to a panel of cell lines, using the Compare analysis to determine the Pearson coefficient correlation, the anti-proliferative spectrum of BIM-46068 has been shown to be distinct from the profile of typical chemotherapeutic agents.

[Glomus tumor of the extremities]. / Tumeur glomique des extrémités.

Glomus tumor is a neuro-myo-arterial benign tumor accounting for 1 to 5% of hand tumors which occurs principally in young adult females. It may be unique or multiple. Acute, focalized, pain is the main sign, the pressure of a small trigger zone induces a syncopal pain and immediate hand withdrawal. Differential diagnoses includes neurinoma, melanoma, hematoma, osteoid osteoma, fibrokeratoma, mucoid cyst, angioma, and exostosis. The diagnosis is suspected on clinical grounds, and X rays exhibits a bone erosion in one third of the cases. Magnetic resonance angiography is now the first line non invasive tool for both diagnosis and precise localization. Treatment consists in complete surgical tumor resection (J Mal Vasc 1999; 24: 364-367).

Subungual glomus tumor: combined use of MRI and three-dimensional contrast MR angiography.

We describe a case of digital glomus tumor diagnosed by MRI and three-dimensional contrast MR angiography (MRA). Images provided the formal definitive diagnosis and the precise localization of the tumor, guiding the necessary surgical resection. It is possible that noninvasive MRA could replace conventional arteriography for the evaluation of patients with clinical suspicion of glomus tumor.

Intradural extramedullary spinal canal secondary neoplasms: MR findings in 30 patients.

The purpose of this study was to describe magnetic resonance findings of intradural spinal canal secondaries and to select the best way of investigating this condition. Thirty patients with a known malignancy [breast carcinoma (n = 14), lung carcinoma (n = 10), other sites (n = 6)] and unexplained neurologic signs were studied with pre- and post-contrast T1-weighted images and T2-weighted images. Cerebrospinal fluid cytology was available in 16 patients and positive in 11 patients. In all the patients, post-contrast T1-weighted images demonstrated abnormal enhanced lesions. Most of them were nodular, located on the conus medullaris and the cauda equina. Few lesions appeared at the thoracic or cervical levels, as nodular or thin areas of enhancement. Pre-contrast T1-weighted sequences failed or were equivocal to detect the lesions. Eighteen of 30 patients had cerebral metastases. Fourteen had osseous metastases. In conclusion, post-contrast T1-weighted sequence is the optimal modality for the diagnostic of intradural spinal canal metastases. Axial and coronal images may be a useful adjunct to precise anatomic changes. T1-weighted and T2-weighted sequences remain necessary when further information is expected on vertebra or soft tissue.