Neuroimaging of acute and chronic unilateral and bilateral thalamic lesions.

The thalami are bilateral ovoid grey matter cerebral structures bordering the third ventricle on both sides, which participate in functions such as relaying of sensory and motor signals, regulation of consciousness, and alertness. Pathologies affecting the thalami can be of neoplastic, infectious, vascular, toxic, metabolic, or congenital origin.The purpose of this review is to provide a comprehensive approach to the thalamus focusing on its anatomy, the main pathologies affecting this structure and their radiological semiology on CT and MRI. We will also illustrate the importance of multimodal MR imaging (morphologic sequences, diffusion-weighted imaging, perfusion, spectroscopy) for the diagnosis and treatment of these conditions.

cDNA cloning of an adult male putative lipocalin specific to tergal gland aphrodisiac secretion in an insect (Leucophaea maderae).

Lma-P22 is a cuticular surface protein specific to the tergal gland secretion of Leucophaea maderae adult males which is ingested by females just before copulation. The complete Lma-P22 cDNA sequence was determined by RT-PCR using primers based on Edman degradation fragments. The recombinant protein expressed in Escherichia coli was recognized by an anti-Lma-P22 antibody. Northern blot analysis indicates that the corresponding mRNA is transcribed only in the epidermis of male tergites. Sequence analysis indicated that Lma-P22 deduced protein belongs to the lipocalin family. Lipocalins are extracellular proteins which carry hydrophobic compounds and some of them can bind sexual pheromone in vertebrates. Lma-P22 is the first example of a lipocalin-like protein involved in insect sexual behavior.

Identification of a nonmammalian Golf subtype: functional role in olfactory signaling of airborne odorants in Xenopus laevis.

Attempts to identify the Galpha subtypes in the two compartments of the olfactory system from Xenopus, which are supposed to be specialized for detecting aquatic and volatile odorous compounds, revealed that a Galpha(o1) subtype is characteristic for the "water nose," the lateral diverticulum, whereas a novel Galpha(s) subtype predominates in the "air nose," the medial diverticulum. The newly identified Galpha(s)-type is more closely related to Galpha(olf) of rat and human than to the known Galpha(s)-isoform of Xenopus; it is therefore considered the first identified nonmammalian Galpha(olf) subtype. Sequence comparison of Galpha(olf) from amphibia and mammals revealed a particular conservation within the alpha-helical domains, which are supposed to control the GDP/GTP-exchange rate. The selective expression of different Galpha subtypes in the two anatomically separated and functionally specialized nasal compartments parallels the expression of distinct classes of olfactory receptors. Moreover, biochemical analysis revealed that stimulation with appropriate odorous compounds elicits the formation of inositol trisphosphate in the lateral diverticulum. In contrast, cyclic adenosine monophosphate signals were induced in the medial diverticulum, and this response appears to be mediated by the novel Galpha(olf) subtype. The data indicate that olfactory sensory neurons in each of the nasal cavities are equipped not only with defined sets of receptor types but also with a distinct molecular machinery for the chemo-electrical transduction process.

Characterization of two male-specific polypeptides in the tergal glands secretions of the cockroach Leucophaea maderae (Dictyoptera, Blaberidae).

During the sexual behavior of cockroaches, the female mounts the courting male to feed on the proteinaceous secretion of the tergal glands. Polyacrylamide gel electrophoresis of male and female protein extracts after cuticle wiping revealed three major bands. Two of 18 and 22 kDa, named Lma-P18 and Lma-P22, are specific to the male tergal extracts. Moreover, Lma-P22 is only found in the male second tergite extracts. The third one of 54 kDa, named Lma-P54, is common to male and female extracts and could be considered as an ubiquitous surface protein. Several other minor proteins are also present on the body surface of adults of both sexes. Quantitation of the total protein amount of the male tergal gland secretion shows a progressive accumulation from adult ecdysis to sexual maturity. Western blot analysis using antibodies raised against Lma-P22 and Lma-P54 confirms that Lma-P22 is only secreted by the male second tergite glands. Immunohistolocalization demonstrates that these three major proteins are produced by class 3 glandular cells.

Whole-body magnetic resonance imaging: an essential tool for diagnosis and work up of non-oncological systemic diseases in children.

AIM: Whole-body MRI (WBMRI) is a non-irradiating imaging technique, suitable to investigate the extent of multisystemic diseases in pediatric patients. However its real impact on diagnosis and management of non-oncological pediatric diseases remains unclear. We present our experience of pediatric WBMRI in various pathologies. METHODS: We retrospectively reviewed medical files of all non- oncologic patients who underwent WBMRI from January 2008 to November 2012. The MRI protocol included T1 weighted and 3D SPACE Inversion Recovery (IR) and fat saturated diffusion weighted (DWI) sequence. We reviewed medical records in order to determine if performing WBMRI added useful information for diagnostic purposes and/or changed clinical management. RESULTS: Forty-two children were included in the study (19 F, 23 M) (median age 4.7 years). Twenty-one children underwent general anesthesia. WBMRI was a useful tool to provide correct diagnosis in chronic recurrent multifocal osteomyelitis (CRMO), and to identify the origin of fever or arthralgia of unknown etiology. WBMRI allowed to determine the extent of disease in juvenile idiopathic arthritis (JIA), chronic granulomatous disorder, enchondromatosis, Langerhans cell histiocytosis, and in the assessment of tumor burden in neurofibromatosis type I. For the battered child syndrome, the influence on management was rather minimal. For each of these pathologies we performed a review of recent literature. CONCLUSION: WBMRI is easy to perform in children and allows the assessment of systemic diseases or discovery of lesions ignored by clinical examination. WBMRI influenced the decisional process and clinical management of various pathologies in our series.

Imaging of the cavernous sinus lesions.

This educational paper reviews the normal anatomy of the cavernous sinus (CS) and the imaging findings of common and uncommon lesions of this region. CS lesions may arise from different components of the CS or from adjacent structures and spaces. They can be classified as tumoral, inflammatory/infectious, vascular and congenital. Tumoral lesions include benign (meningiomas, pituitary adenomas, schwannomas) and malignant neoplasms (chondrosarcomas, chordomas, nasopharyngeal carcinomas, leukemia, metastases). Inflammatory/infectious conditions comprise: Tolosa Hunt, abscess, Lemierre syndrome and thrombophlebitis. Vascular lesions include: hemangiomas, carotido-cavernous fistula, aneurysms, arteriovenous malformations. Congenital conditions include the epidermoid cyst, dermoid cyst and fatty deposits. Although imaging features of non-vascular CS diseases are most often non-specific, careful analysis of the adjacent structures suggests the correct diagnosis. In vascular pathology, characteristic MR imaging findings are observed.

[Intracranial empyemas: Epidemiological, clinical, radiological and therapeutic aspects. Retrospective study of 100 observations]. / Les empyèmes intracrâniens : aspects épidémiologiques, cliniques, paracliniques et thérapeutiques. Étude rétrospective de 100 observations.

INTRODUCTION: Intracranial empyema is a frequent complication of ear-nose-throat (ENT) infections. Limited studies have been carried-out on cerebral empyema during recent years in Senegal. Despite new imaging techniques, diagnostic and therapeutic problems as well as outcome still remain in our regions. We report our experience compared to that of the literature. The study focused on epidemiological aspects, difficulties in diagnosis and treatment as well as prognosis of this condition. METHODS: This was a retrospective study conducted from January 2008 to December 2011 of 100 clinical cases. Diagnosis was made based on contrast CT-scan. Twenty-one percent of patients received medical treatment alone, while 79% underwent surgery. The duration of the treatment varied from 4 to 8 weeks. The follow-up was clinical and radiological with a mean follow-up time of 12 months. RESULTS: Cerebral empyema represented 44.4 % of all intracranial suppuration cases and the mean age was 21 years. The etiology was ENT in 35%, meningitis 10%, unknown 25%. Localization was sub-dural in 57%, extra-dural in 22%, inter-hemispheric in 10% of the cases. Empyema was associated with an abscess in 7 cases. One case was located in the posterior fossa. The evolution was favorable in 78% of the cases and in 12.5% some neurologic sequelae were observed. Eleven patients died and 3% of the patients had recurrences. CONCLUSION: The frequency of intracranial empyema is still high in Senegal. Difficulties in diagnosis, therapeutics and low economic incomes account for the gravity of intracranial empyema. In spite of these risks, early stage and effective treatment is necessary to reduce the morbi-mortality, especially in young aged children.