Artificial blood: the future of blood transfusion? II. Blood substitutes other than hemoglobin solutions

Part 2 discusses the state-of-the-art in oxygen-transporting blood substitutes other than hemoglobin solutions (Part 1); these are the fluorocarbon emulsions, the hemoglobin liposomes and other products such as oxygen-chelating agents. The substitutes reviewed here may play an important future role; before then, their stability, ease of administration, innocuity and value in human clinical medicine must be ensured.     

"Spike focus" during the evolution of febrile convulsion: an electrophysiological and clinical study of 35 patients (author's transl)

Out of 500 patients with febrile convulsions, 41 were found to have a spike focus on E.E.G., 35 of these were then followed up. The clinical features of the seizure in these 35 children did not differ from the group in general. The initial focus was practically always unilateral, except for one case with an asynchronous bioccipital focus. The most frequent site was occipital (43 p. 100). Migration of the focus was relatively rare. In 35 patients the focus disappeared, in 45 p. 100 within a year and in 88 p. 100 within 3 years. Following the disappearance of the focus, generalised sharp wave activity was seen in 30 p. 100 cases, all 35 children being under treatment. All the seizures with the exception of two children who have become epileptic were benign rendering long term anticonvulsant therapy unnecessary.     

Development of Cryptosporidium parvum-Induced Gastrointestinal Neoplasia in Severe Combined Immunodeficiency (SCID) Mice: Severity of Lesions Is Correlated with Infection Intensity

We reported previously that Cryptosporidium parvum was able to induce intestinal tumors in severe combined immunodeficiency (SCID) mice treated with corticoids. To further characterize this Cryptosporidium-induced cell transformation, SCID mice treated with dexamethasone were challenged with C. parvum oocysts, and euthanatized sequentially after infection for histologic examination. Ki-67 was used as a marker of cellular proliferation. Our previous results were confirmed, and it was also found that mice receiving higher inocula (10⁶–10⁷) experienced more severe neoplastic development. Additionally, neoplastic changes were observed not only in the caecum but also in the stomach and duodenum of some animals. Interestingly, SCID mice (6/6) inoculated with 10⁵–10⁷ oocysts showed high grade intraepithelial neoplasia or adenomas with high grade dysplasia in the caecum after Day 46 post-infection (PI). Immunohistochemistry for Ki-67 staining indicated the neoplastic process associated to cryptosporidiosis, and evidenced the first immunohistochemical alterations at early stages of the process, even at 3 weeks PI.     

Diagnosis of cerebellopontine angle tumors.

Between 1980 and 1990, 9,176 patients suffering from otoneurological disorders were investigated in our clinic. Sixty-six (0.72%) internal auditory canal or other cerebellopontine angle tumors (CPAT) were diagnosed. Brainstem auditory evoked potentials (BAEP), interaural time discrimination, and magnetic resonance imaging (MRI) revealed to be the most sensitive and efficient tests for the detection of CPAT. However, the investigation of otoneurological symptoms cannot be limited to BAEP and MRI on the a priori of a hypothetical CPAT. Electrophysiologic tests such as impedancemetry, and electronystagmographic testing are also needed to elucidate the many causes of otoneurological symptoms.     

Perméabilité des matériaux copolymères: modélisation moléculaire, 1. Essai d'application d'un modèle de percolation

The diffusion of small molecules across a copolymer membrane is simulated as a site percolation problem, assuming that in copolymers consisting of A and B units, B are active sites and A are inactive sites. Molecular modeling is conducted in three steps: (i) generation of a copolymer by a Monte-Carlo process, taking into account the sequence distribution of the copolymer, (ii) organization of the material through a slipping process of the linear chain towards maximization of the dipolar interactions between the A units, and (iii) the site percolation itself. A quantitative application is carried out for acrylonitrile/methyl acrylate copolymers. The results show that the influence of the slipping process upon the internal organization of the material is most important.