PubMed Health⌕ Search

Biomedical subjects

F Muller

Publications and source records attributed to F Muller.

At least 163 records · Page 9Linked to original sources

Molecular forms and solubility of acetylcholinesterase during the embryonic development of rat and human brain.

Acetylcholinesterase (EC 3.1.1.7) and butyrylcholinesterase (EC 3.1.1.8) form homologous sets of multiple molecular forms. The central nervous system of mammals contains mostly tetramers (G4) and monomers (G1). Their proportions have been shown to vary during maturation in rat brain. In order to examine whether a similar evolution occurs in the human, we performed parallel studies of the activity, solubility and molecular forms of acetylcholinesterase in rat and human brains at various stages. We find both similarities and differences: in rat brain, the enzyme increases mostly postnatally but in human brain acetylcholinesterase reaches a maximum at birth. There is an increase in the proportion of G4 and a decrease in the solubility of this from in the absence of detergent in human as well as in rat brain. These changes occur around birth in rat, but during early pregnancy, before 11 weeks in human brain. In both species, the solubility of the enzyme in detergent-free buffers decreases progressively from more than 50% before birth to about 10-20% in the adult. In addition we analyzed butyrylcholinesterase as well as the levels of the neuron-specific enolase and of the glial S-100 protein. In human, gamma gamma-enolase rises to its adult level after birth, but before the S-100 protein.

Acetylcholinesterase↗

Partial bronchial stenosis following inadvertent right bronchial intubation in a neonate.

This case reports difficulties encountered in weaning a premature infant with bronchopulmonary dysplasia from prolonged mechanical ventilation. On chest X-ray alternating atelectasis and hyperinflation of the right lung were observed. This resulted from a short episode of misplaced endotracheal tube that produced a traumatic bronchial stenosis. Treatment by prednisolone allowed the detubation.

Bronchi↗

[The concept of protein profile].

From their own experience of the simultaneous immunonephelometry of eight serum proteins, the authors propose a definition of protein profile from the point of view both of laboratory technique and interpretation. The assay should be performed quickly and the results expressed diagrammatically in normalised values, in such a way that the relative variation in protein levels can be easily visualised. A protein profile should thus comprise a minimum of proteins to be measured, chosen according to protein physiopathology and the type of abnormality under investigation. Interpretation is based on inter-protein correlations that may appear or disappear depending on the underlying physiopathology. This makes it possible to study inter-protein variation and thus avoid the probabilistic "interpretation" of single proteins taken in isolation. From this approach syndromes can be divided into two groups, elementary or complex. The authors provide examples of each, and propose an interpretation model based on this dichotomy.

Blood Protein Electrophoresis↗

[Gammopathies with oligoclonal electrophoretic patterns. Incidence, immunochemical nature and association with neoplastic pathology].

Electrophoretic study of 680 cases of human sera containing monoclonal bands showed an oligoclonal pattern in 92 cases (13.5%). Immunoelectrophoretic analysis of 52 oligoclonal cases showed various patterns: polyclonal in 12 cases, monoclonal in 23 cases, monoclonal with associated Bence Jones proteinemia in four cases, and biclonal in only 13 cases. In cases lacking immunoelectrophoretic evidence for the oligoclonal nature of gammopathy, a restricted heterogeneity in molecular weight of subunits was evidenced in 12 out of 27 cases. Associated diseases were investigated comparatively in the monoclonal and the oligoclonal groups. A significant increase in cancer aetiology was found in the oligoclonal group (p less than 0.0005).

Electrophoresis↗

Comparative affinity chromatography of acetylcholinesterases from five vertebrate species.

The efficacy of N-methylacridinium affinity chromatography in the purification of acetylcholinesterases from chicken, rat, calf and human brain and from the electric organ of the electric fish Torpedo marmorata has been investigated. Retention of the enzymes on the N-methylacridinium columns exceeded 90% in all instances except for the chicken enzyme, where 40-80% retention was observed depending on the acridinium concentration. Sucrose density gradient centrifugation profiles revealed no difference between the distribution of molecular forms in the crude extracts and in the partially purified fractions eluted from the columns by decamethonium iodide.

Acetylcholinesterase↗

Survival following massive overdose of adrenergic blocking agents (acebutolol and labetalol).

Massive overdosage of adrenergic blocking drugs is associated with severe morbidity and a high mortality rate. We report the case of a 24-year-old medical intern who ingested 9.6 g acebutolol, 7.2 g labetalol and 0.625 g trimipramine in an attempted suicide. Blood samples drawn on admission were shown to contain markedly elevated plasma levels of acebutolol and its major metabolite and of labetalol. The patient was deeply comatose on admission. The heart rate was 60 min-1 (sinus rhythm) and the blood pressure was clinically unrecordable. Atropine, isoproterenol and dopamine initially had no effect on either heart rate or blood pressure. Only following the administration of inordinately large doses of isoproterenol and dopamine, together with glucagon was a clinical response obtained. The patient remained haemodynamically dependent on dopamine for 12 h and isoproterenol for 65 h. The total dose of isoproterenol administered was 260 mg, two thirds of this during the first 12 h. The patient left hospital well after 7 days but was readmitted after 26 days because of intestinal obstruction due to ischemic bowel necrosis.

Acebutolol↗