[Computed tomography in thoracic pathology]. / Le scanner en pathologie thoracique.

The fundamental principles of computed tomography (CT), its clinical applications and costs are presented followed by the indications and results in diseases of the mediastinum, the oesophagus, heart and great vessels, and the lung and pleura. The CT scan can give the precise localization and density of mediastinal tumours and be used to distinguish thymomas, goiters, lymph nodes, lymphomas, neurinomas and different bronchogenic and pleuropericardial cystic formations. The operability of oesophageal cancer can also be determined. In cardiovascular diseases, the CT scan is particularly useful to identify inborn anomalies, aneurysms, aortic dissection or caval compression or thrombus formation. In lung diseases, the indications for a CT scan are particularly important in bronchopulmonary cancer, tuberculosis, bronchopathies and chronic lung diseases. In bronchogenic cancer, for example, the CT scan is not only a major diagnostic tool but is also particularly useful in determining the prognosis and for following the effectiveness of treatment. The CT scan can be used to identify both effusions of liquid and gas as well as pleural reactions producing thick membranes of importance for both aetiology and later follow-up. Bronchectasis can be identified on serial sections where the degree of extension can be measured. CT scan is also indicated in patients with emphysema, both for evaluating extension and follow-up. Finally the indications and contraindications for interventional computed tomography, particularly in guiding needle biopsies, is presented.

[Magnetic resonance imaging in thoracic diseases]. / Apports de l'imagerie par résonance magnétique en pathologie thoracique.

Most all the thoracic structures are visible with magnetic resonance imaging: the mediastin, the myocardium including the endocardium and the pericardium, the pulmonary parenchyma and hile and the pleural walls. In cases of mediastrinal masses, T1 images clearly delimit their relations with neighbouring organs and vessels. The intensity of the signal is compared with that of the muscles on T1 weighted images of the preceding sections and T2 weighted images of fat. Images of aneurysms and chronic dissections can be synchronized with the ECG allowing three-dimensional measurement of the size and thickness of the vessel walls. Thrombi or extension to other vessels can also be recognized. Small hilar tumours can be differentiated from vessels but the scanner is better for analyzing systematization and bronchial lesions. For lung tissue itself, magnetic resonance imaging can detect nodules greater than one centimeter in diameter, but the low proton density and respiratory movements hinder spatial resolution. MRI is indicated for localizing tumours situated anteriorly or posteriorly or at the apex and to identify parietal extension of peripheral cancers. Spinal, vascular, pericardial, diaphragmatic and lymph node metastases can be recognized. MRI is the noninvasive method of choice for evaluating left ventricular masse, intra and paracardiac mass studies and for investigating congenital and acquired cardiomyopathies. Technical advances have made it possible to evaluate myocardial perfusion and heart function.

Physiology of beta-endorphins. A close-up view and a review of the literature.

When an endogenous morphine, beta-endorphin was discovered ten years ago, the fact that this morphine is present in the brain and many other tissues suggested to neurobiologists that these peptide opiates play a role which goes beyond that of a simple modulator of the perception of pain. beta-endorphin is a neurohormone which is secreted by the pituitary gland and reaches all tissues present in the body by diffusion. Many laboratories have investigated variations in serum levels of beta-endorphin under widely varying physiological or pathological conditions. Many references to these studies in the literature have thus demonstrated that beta-endorphins play a role in certain behavioural patterns (stress, alcoholism), in obesity, diabetes and psychiatric diseases. In fact, the activity of beta-endorphins would appear to have an interesting role to play and are a promising feature in the treatment of cerebral aging; in this field, beta-endorphins act not only as neuroregulators of other neurotransmitting substances but also, via calcium channels, exert an effect on the walls of cerebral arterioles. In situ, the role of beta-endorphins at the ionic channel level has been studied using the patch-clamp technique. In 1991, E Neher and B Sakmann received the Nobel Medicine and Physiology Prize for this work. beta-endorphin, which may be the "missing link" between the neuron and the wall of the arteriole, must be considered as being a fundamental neurotransmitter in the same way as well-known substances such as noradrenaline, acetylcholine, serotonin, dopamine and the GABAergic system are also neurotransmitters.

[Celiac disease, dermatitis herpetiformis and erosive jejunoileitis]. / Maladie coeliaque, dermatite herpétiforme et jéjuno-iléite érosive.

A 21-year-old man with coeliac disease and dermatitis herpetiformis presented successively with erosive ileitis (warranting surgical resection) and erosive jejunitis (proven by jejunoscopy). Discontinuous antibiotic therapy was associated with a gluten-free diet and evolution was favorable as judged with five years follow-up. Malabsorption with mucosal ulcerations can be due to: a) chronic ulcerative duodeno-jejuno-ileitis or Jeffries' disease; b) coeliac disease which may be classified as possible, probable, or certain according to the strictness of criteria. Our case is the fourth in which a villous response was proven after gluten-free diet. It is also particular in that the erosions were superficial; c) malignant lymphoma which can reasonably be excluded here. This observation confirms that a gluten-free diet may be effective after surgical resection of the ulcerated segment in complicated coeliac disease and shows that antibiotics may be an useful adjuvant to therapy.