The topological pressure-temperature phase diagram and crystal structures of the dimorphic system spiperone.

The topological pressure-temperature phase diagram for the dimorphism of spiperone, a potent neuroleptic drug, has been constructed using literature data and improved crystal structures obtained with new crystallographic data from single-crystal X-ray diffraction at various temperatures. It is inferred that form II, which is the more dense form and exhibits the lower melting temperature, becomes the more stable phase under pressure. Under ambient conditions, form I is more stable.

Differentiating amorphous mixtures of cefuroxime axetil and copovidone by X-ray diffraction and differential scanning calorimetry.

The amorphous, molecular solid dispersion of cefuroxime axetil and copovidone with the mass ratio 71/29 is compared to its pure components in the amorphous state and to an amorphous mechanical mixture with the same mass ratio. Calorimetric studies demonstrate that all these materials are vitreous. By using X-ray diffraction profiles, a clear difference can be observed between the local order of the solid dispersion and that of the mechanical mixture. More generally, it is shown how the presence or absence of additivity in the diffraction data can be used to distinguish between different amorphous mixtures.

[Imaging findings in Lemierre syndrome]. / Syndrome de Lemierre: apport de l'imagerie.

Lemierre syndrome is a septic thrombosis of the internal jugular vein with pulmonary abscesses secondary to untreated pharyngotonsillitis due to anaerobic bacteria. It occurs in young, previously healthy patients and leads to life-threatening consequences if not treated. We illustrate the value of imaging and particularly cervical and thoracic CT in a report of three recent cases.

[Lemierre's syndrome: literature review]. / Syndrome de Lemierre: revue de la littérature.

OBJECTIVES: Our aim was to recall the pathogenesis, clinic aspects and therapeutic options for Lemierre's syndrome. PATIENTS AND METHODS: This was a retrospective study (1998-2005) of 4 patients, 3 males and 1 female, average age 22 years (18-30). Bacteriological samples, a chest radiograph and a cervical and thoracic CT-scan with injection were available for all patients who were given broad spectrum antibiotic therapy for 3 to 6 weeks. Surgical treatment was necessary for 3 patients. A review of the literature from Medline was performed. RESULTS: Three patients had a peritonsillar abscess. All of them exhibited thrombophlebitis of the internal jugular vein or one of its tributary branches. In all patients, metastatic infections were noted. In one, arthritis and mediastinitis were associated. The causal microorganism was Fusobacterium (necrophorum--2, nucleatum--1) in three patients. In one, bacteriological samples were negative. Transfer to an intensive care unit was necessary for one patient. There were no deaths. CONCLUSIONS: Lemierre's syndrome is a rare but acute medical condition which concerns young immunocompetent people. The pathogenesis consists of the development of infectious thrombophlebitis in the internal jugular vein or one of its tributary branches caused by a focal sepsis, localized in most the cases in the oropharynx, leading to metastatic infections, generally to the lung. Treatment is medical but surgery is sometimes required.

[Imaging benign tumors of the pleura]. / Imagerie des tumeurs bénignes de la plèvre.

Five percent of pleural tumors are benign. Solitary fibrous tumors are the most frequent. We recall the clinical and pathological features and present the radiographic, computed tomographic and magenetic resonance imaging results obtained for the main types of benign tumors of the pleura.

[Crystallography of drug polymorphism: emergence of new resolution methods and prediction of crystalline structures]. / Cristallographie du polymorphisme des médicaments: émergence de nouvelles méthodes de résolution et de prédiction de structures cristallines.

For the pharmaceutical and agrochemical industries, reducing development time is currently a primary objective to accelerate the marketing of new products. In-depth solid-state characterization is an essential element in achieving this performance. For this purpose, it is now recognized that, in a department of solid-state physical characterization, theoretical approaches have to be integrated with experimental tools. Benefiting from the constant improvement in computer hardware and software in terms of computing powers and algorithm development, these approaches appear to be a complementary method that can help explain and rationalize experimental data. In recent years, with the help of both molecular modeling tools and crystallographic databases, original methods have been developed and successfully applied to systems of variable complexity. The X-ray diffraction crystal structure determination makes it possible to calibrate the force field and to adapt it more precisely to the compound studied, thereby reducing one of the sources of uncertainty. Although crystal structures are preferentially determined from single crystal data, it has been recently shown that powder diffraction data can also be used when single crystals are missing. Therefore, the different benefits of such an approach are the following: ab initio predictive study of crystalline polymorphism, molecular packing analysis and detection of cleavage planes, prediction of morphology in vacuum. In conjunction with crystallite preferred orientation observed in powder patterns, grinding effects on the crystal habit and solvent effects in modifying growth can be clearly understood. Selected industrial cases exemplify the operational application of this methodology.