Characterization of reactions catalysed by yeast phosphatidylinositol synthase.

The nature of reactions catalysed by yeast phosphatidylinositol synthase expressed in E. coli has been investigated. The single enzyme is shown to carry both CDP-diacylglycerol-dependent incorporation of inositol into phosphatidylinositol (Km for inositol of 0.

Active transport of L-proline in the protozoan parasite Trypanosoma brucei brucei.

The characteristics of L-proline transport in the procyclic form of Trypanosoma brucei were studied by using L-[14C]proline and a quick separation technique by centrifugation through an oil mixture. L-Proline uptake displayed typical Michaelis-Menten kinetics, with a Km of 19 microM and a maximum transport velocity of 17 nmol/min per 10(8) cells at 27 degrees C. The maximum concentration gradient factor obtained after 1 min of incubation was 270-fold in 0.

[Tomodensitometric aspects of the narrow lumbar canal].

Thirty of 200 cases of lumbar radiculalgia of degenerative origin presented clinical, radiologic, saccographic, and computed tomography signs of a typical narrow lumbar canal, half of these patients having benefited from surgical mobilization of the neuromeninges. Performances of new generation scanners have enabled the development of computed tomography images typical of a narrow lumbar canal, and also to improved assessment of radiotomographic and saccographic signs, as a result of direct visibility of osteo-articular radicular constrainst factors in the transverse axial plane. Findings in stenotic dysplasia, the role of vertebral arthrosis, the particular cases of spondylolisthesis, and the entity determined by isolated stenosis of the nerve root canal (mainly stenosis of the lateral recess) are discussed.

[The value of tomodensitometry in the diagnosis of dermoid cysts. Apropos of 5 cases].

Results of computed tomography before operation in 5 cases of dermoid cysts (mediastinal: 3; retroperitoneal: 1; ovarian: 1) are employed to assess the contribution of this technique, and to define its place in relation to other diagnostic radiological procedures (straight radiographs and ultrasonography). The CT scan enables three morphological types to be distinguished, and also supplies very precise data on the extension, limits, and relationships of the tumor. The effective place of this examination in the diagnosis of dermoid cysts depends upon two factors: data obtained from the straight radiograph and the initial site of the lesion.

[The new radiology].

After a brief analysis of the relations existing between the disciplines of Radiology, Biophysics, and Clinical Medicine, and, the political and administrative sectors, certain themes are developed concerning general problems related to modern radiology: its true place in Medicine today, its evolution, and its organization as a function of current technological advances. Among the questions discussed are the training of new radiologists, the development of complex technical equipment and thus the mode of practice of radiology, the organization of hospital teams and the recruitment of staff adapted to perform tasks of increasing diversity, and the future of research in this field.