Biomedical subjects
Publications and source records attributed to S Bacha.
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OBJECTIVE: To demonstrate that DNTs include a large morphological spectrum of tumors that cannot be histologically distinguished from conventional categories of gliomas. METHODS: All tumors from patients who underwent epilepsy surgery in Sainte-Anne hospital (Paris) that histologically resembled gliomas and did not conform to current histological criteria for DNTs or gangliogliomas were entered in the study. RESULTS: According to the WHO histological classification, the 40 tumors resembled: pilocytic astrocytomas (4 cases), astrocytomas (16 cases), anaplastic astrocytoma (1 case), oligodendrogliomas (10 cases), oligo-astrocytomas (8 cases) or anaplastic oligo-astrocytomas (1 case). However foci of cortical dysplasia could be observed in 47% of the cases. Clinical presentation and imaging features were strikingly similar to that observed in typical DNTs. Although surgical removal was incomplete in 28% of the cases and none of the patients underwent chemo or radiotherapy, none of the tumors recurred (mean follow-up: 7 years). Moreover, serial preoperative imaging in 26 patients (mean follow-up: 4.5 years) demonstrated that these lesions were perfectly stable. CONCLUSIONS: Whatever the histological appearance of a glial tumor, the diagnosis of DNT must be considered when all the following criteria are associated: (1) partial seizures, with or without secondary generalization, beginning before the age 20 years, (2) no neurological deficit or stable congenital deficit, (3) cortical topography of the lesion as better demonstrated by MRI and (4) no mass effect on imaging.
The incidence of iatrogenic air embolism can only be estimated since many accidents are not recognized. Clinical manifestations, essentially neurological or cardiovascular disorders vary greatly. Air embolism may occur during coronary or cerebral arteriography, cardiopulmonary bypass, venous catheterism, various types of surgery or blood transfusion among other situations. Once air has entered the arterial circulation, the bubble of gas follows the blood flow until it is blocked by a smaller calibre vessel. The progressive diffusion of the air reduces the size of the embolus which then migrates on to smaller and smaller vessels. Subsequent pathological manifestations of air embolism result from mechanical obstruction leading to ischemia and inflammatory reactions to air acting as a foreign body. The sudden onset signs of neurological impairment with or without a cardiopulmonary component in patients in a high-risk situation leads to clinical diagnosis. Treatment must be started immediately although brain CT scan or echocardiography may help confirm the diagnosis. The source of the air must be immediately identified and removed and the vital functions controlled. Mechanical or facial mask ventilation with pure oxygen is indicated. Hyperbaric oxygen therapy should be instituted. Morbidity and mortality after iatrogenic air embolism is high but major improvements have been achieved with oxygen therapy. Neurological sequellae have been estimated to reach 19 to 50% of the patients. A personal controlled prospective study revealed 14% mortality after hyperbaric oxygen therapy given within 12 hours of the accident.
BACKGROUND: Ingestion of nickel (Ni) has been demonstrated to induce a specific state of tolerance in the guinea pig and mouse. In a pilot study conducted in 10 patients, we demonstrated that per os administration of Ni leads to reduced proliferation of specific lymphocytes and a lower number of responding lymphocytes in blood. The aim of this study was to evaluate the clinical and biological changes induced by the ingestion of Ni in a double-blinded placebo-controlled study. PATIENTS AND METHODS: Patients with nickel contact hypersensitivity were given a capsule of nickel sulfate containing 5 mg Ni (group A) or an identical placebo (group B) once a week for 7 weeks. Clinical criteria were assessed 49 days after study onset: objective measurement of lesion extent and intensity and quantitative patch tests at concentrations 2.4-0.8-0.2 and 0.05 p. 100. Likewise stimulation of specific lymphocyte proliferation and the number of circulating lymphocytes responding to Ni at limit dilutions were determined. RESULTS: Thirty patients with nickel contact eczema were included in the study, 28 women and 2 men. There was no statistical difference between the two groups for the intensity of skin lesions or their clinical course, quantitative patch tests and lymphocyte stimulation tests. Conversely, the number of circulating lymphocytes responding to Ni was significantly lower in group A than in group B at study end (p < 0.05). DISCUSSION: This double-blind placebo-controlled study confirmed that per os nickel can induce a significant reduction in the number of circulating lymphocytes responding to Ni. No other effect could be demonstrated for the clinical and biological parameters studied. These preliminary results should prompt a multicentric controlled trial including a larger number of patients with more severe lesions at inclusion and with a longer treatment duration.