PubMed Health⌕ Search

Biomedical subjects

F Lionnet

Publications and source records attributed to F Lionnet.

46 records · Page 3Linked to original sources
PubMed1991

Multifocal multinucleated giant cell myelitis in an AIDS patient.

A 19-year-old male intravenous drug abuser, was admitted to hospital with a one-week history of lower limb weakness and urinary retention. He was known to have been HIV-seropositive for 3 years and had been treated for cerebral toxoplasmosis. Neurological examination confirmed flaccid paraparesis with weak ankle jerks and bilateral extensor plantar responses. There was no obvious sensory deficit. Neurological examination was otherwise normal. CSF contained 63 mg/dl protein and 10 leucocytes/mm3. Myelography was normal. He died 1 month later from septic peritonitis. Neuropathological examination showed chronic lesions of toxoplasmosis in brain. Small necrotic foci with myelin loss, proliferation of microglia, macrophages and multinucleated giant cells (MGC) were disseminated in the whole spinal cord, mostly in the white matter, but the brain was spared. Immunohistochemistry demonstrated p24 and p17 HIV antigens in macrophages, MGC and microglial cells. These lesions resemble those of so called 'multifocal giant cell encephalitis'. The present case demonstrates that HIV-related multifocal inflammatory changes may be restricted to the spinal cord and may be a cause of myelopathy in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Neuropathologic study of 135 adult cases of acquired immunodeficiency syndrome (AIDS)].

The central nervous system was examined in 135 adult AIDS patients who died between August 1982 and December 1990. Twenty two brains showed non-diagnostic changes including microglial nodules, discrete myelin pallor with reactive astrocytosis, mineralization of blood vessels and granular ependymitis. In 105 brains with specific changes, toxoplasmosis was the most frequent finding (55 cases) manifested by multifocal necrotic lesions or diffuse pseudo-encephalitic process. Other opportunists included cytomegalovirus (21 case), progressive multifocal leukoencephalopathy (1 cases), cryptococcosis (6 cases), mycobacterium avium intracellulaire (2 cases), varicella-zoster virus (2 cases), aspergillosis (1 case) and multiple bacterial microabscesses (1 case). Multinucleated giant cells were found in 52 cases. In 40 cases, they were widely disseminated throughout the brain and in 39 cases, they were associated with diffuse or multifocal white matter changes. Fifteen cases had a cerebral lymphoma, 9 hepatic encephalopathy, 1 centropontine myelinolysis and 1 focal pontine leukoencephalopathy. Three cases had a cerebral haemorrhage due to disseminated intravascular coagulation, antithrombin therapy and amyloid angiopathy. Spinal changes in 13 cases included vacuolar myelopathy (7 cases), HIV myelitis (1 case) and ganglio-radiculitis (1 cases), cytomegalovirus myelo-radiculitis (1 case) secondary spread from a lymphoma (1 case) and spinal infarcts due to disseminated intravascular coagulation (1 case). These lesions were frequently atypical and various combinations of all these pathologies were encountered in the same brain, sometimes in the same area and occasionally in the same cell. Chronological variations in the incidence of some complications could be related to changes in treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Assessment of antacid characteristics of drugs containing a combination of aluminium and magnesium salts using the "artificial stomach" model.

Antacid characteristics of three drugs containing aluminium and magnesium salts (combination of clay with aluminium and magnesium hydroxides, aluminium and magnesium hydroxide mixture and hydrotalcite) have been studied in a dynamic situation simulated by the "artificial stomach" model, simultaneously taking into account both gastric fluxes, a constant secretory flux and variable emptying fluxes. Therapeutic doses of the drugs were added 1. to 100 ml of 0.1 N HCl, without or with 1% or 5% meat extract, and 2. 100 ml of pooled human gastric juice (96 mmol/l, pH 1.1). In addition, antacid activity of 0.5 g aluminium and magnesium hydroxides, taken alone or in combination, were evaluated when added to 100 ml of 0.1 N HCl. In aqueous HCl solution or in human gastric juice, the three antacid drugs exhibited 1. a neutralising activity characterised by pH-rise and 2. a buffering capacity close to pH 3.8. In addition, hydrotalcite exhibited also buffering capacity at pH 1.2. The antacid-induced capacity, expressed as H+ mmol, to recover initial pH were very similar, indicating that antacid physiochemical properties are similar in HCl solution or in gastric juice. H+ consumption depended upon emptying fluxes. The same antacid characteristics were observed when antacids were mixed with 1% meat extract while 5% meat extract resulted in a modification of antacid characteristics. Therefore the antacid capacities of respective mixtures were of smaller magnitude (50-60%) than the sum of the activities of antacids plus meat extracts.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Hydroxide↗
PubMed1988

[Home thrombolysis for myocardial infarction. A multicenter study of the feasibility and evaluation of short-term prognosis].

It has been proven since 1986 that in myocardial infarction the sooner thrombolysis is performed the better. Forty-four patients were selected to enter a double-blind randomized trial in which they received either an acylated plasminogen streptokinase activator complex or a placebo. The injections were given intravenously at home within the first 3 hours (within the first 2 hours in 26 of them), by doctors from Mobile care units. This home treatment in the acute phase made it possible to gain 75 minutes on average, and up to 90 minutes when it was performed by an anaesthetist trained in emergency management. No serious complication, such as haemorrhagic or allergic reaction, occurred, and arrhythmia was no more frequent in the treated group than in the placebo group. Home thrombolysis did not delay admission to a cardiology Intensive Care unit (66 min. versus 64 min). Mean coronary patency was 75 per cent, and up to 82 per cent, in patients treated within 2 hours of the first symptoms. There was no significant difference between areas of reperfused or not reperfused patients in relation to time (P less than 0.08). Diagnosis sensitivity was 100 per cent. Thus, home thrombolysis is feasible and safe when performed by trained emergency medical teams and when criteria for inclusion and exclusion are fulfilled.

Double-Blind Method↗
PubMed1988

A model of an 'artificial stomach' for assessing the characteristics of an antacid.

A model of an 'artificial stomach' has been constructed in order to take into account some of the parameters lacking in conventional in vitro antacid evaluation, namely the interaction between secretory flux and variation in emptying fluxes, the presence of proteins, and the use of human gastric juice instead of an aqueous solution of hydrochloric acid. The 'artificial stomach' has two elements, the 'stomach' and the pH recording system. The 'stomach' includes a 'gastric' reservoir receiving secretory flux and is emptied by variable fluxes. Aluminium phosphate gel has been studied in 100 ml of 0.1 N HCl, without and with 1 or 5% meat extracts and also in 100 ml of human gastric juice. The antacid effect of 1 or 5% meat extracts has also been assessed. The antacid effect of aluminium phosphate was characterized by the pH rise of the 'gastric' contents, the buffering capacity, and the dilution of gastric contents. These factors were modulated by emptying fluxes. The same characteristics were found when antacid was studied in gastric juice. Proteins exerted a neutralizing effect and modified aluminium phosphate's antacid capacity. A mechanism for buffering capacity by cation aluminium is suggested.

Antacids↗
PubMed1987

Torsade de pointes during loading with amiodarone.

Torsade de pointes represents a potential complication of chronic amiodarone therapy. Several reports have emphasized the need for a loading dose in order to achieve therapeutic blood levels rapidly. We report a case of torsade de pointes following a single oral dose of amiodarone (1400 mg or 30 mg kg-1) administered after short intravenous loading for prevention of paroxysmal atrial flutter. Torsades de pointes were preceded and associated with marked QT prolongation and bradycardia. This report suggests that careful monitoring of patients undergoing oral amiodarone loading is necessary.

Administration, Oral↗
PubMed1987

[Antacid action of the aluminum cation: comparison of the in vitro effect of hydroxide and phosphate in open and closed systems].

Antacid capacity of two aluminium containing-antacid drugs was evaluated in vitro; the first drug contained aluminium hydroxide (Alternagel), the second, aluminium phosphate (Phosphalugel). The antacid evaluation was performed 1) in a closed system by measuring antacid activity by down titration, 2) by a dynamic evaluation simulating acid secretion and gastric emptying. The results were reported both to the recommended therapeutical dose and to 100 mg aluminium. In static conditions, without gastric emptying, it was shown that aluminium hydroxide and phosphate acted by their buffer capacity in pH range less than or equal to pH 1.5. The therapeutical dose of aluminium phosphate displayed greater antacid activity than aluminium hydroxide, this fact being due to the empiric choice of the doses. With regard to aluminium content, aluminium phosphate activity remained greater than that of aluminium hydroxide although the difference decreased with decreasing pH values. The antacid capacities were related to the emptying outputs. Antacid activity corresponding to 100 mg aluminium was similar in both antacids less than pH 1.5. This effect was dependent on emptying rates. It can be suggested that Al was responsible for antacid activity in both preparations, and that the buffering capacity was supported by the change of aluminium cation in hydrolysis intermediary compounds.

Aluminum↗
PubMedDate not supplied

[Evaluation of the antacid properties of Gelox in a dynamic milieu using the artificial stomach apparatus].

Gelox antacid activity has been evaluated in a dynamic procedure by using the "artificial stomach" model that mimics both gastric fluxes, gastric secretion and gastric emptying. At time 0, the gastric reservoir has been filled by 100 ml of 0.1 N hydrochloric acid solution without or with protein, or by 100 ml of human gastric juice (pH 1.1). Gastric secretion was simulated by a constant 3 ml/min flux of HCl solution or of human gastric juice. Gastric emptying fluxes varied from 1.5 to 4.5 ml/min. Gelox addition to 100 ml of 0.1 N HCl or of human gastric juice induced 1) a pH-rise from 1.0 to 4.5-5.8, 2) a buffering capacity close to pH 3.6-4.0 and 3) the consumption of an acid amount between 25 and 50 mmol according to emptying fluxes, for recovering initial pH. In a mixture of HCl 0.1 N and protein extract 1 or 5%, Gelox induced 1) a pH-rise related to the protein concentrations, 2) a buffering capacity close to pH 3.2-3.9 when 1% protein extract has been used, and close to pH 5.0-5.9 with 5% protein extract and 3) a greater acid consumption with 1% than with 5% protein extract. For both protein concentrations, the resistance for recovering the initial pH, expressed as the amount of consumed mmol H+, was therefore less than the sum of individual capacities of proteins and Gelox.(ABSTRACT TRUNCATED AT 250 WORDS)

Antacids↗