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Biomedical subjects

I M Steven

Publications and source records attributed to I M Steven.

14 recordsLinked to original sources

Metabolism of halothane in children having repeated halothane anaesthetics.

Metabolism of halothane was studied in nine children receiving daily halothane anaesthetics (from 10 up to a maximum of 31) over periods of two to seven weeks. Serum bromide concentrations never exceeded 3.5 mmol/l, a concentration below the toxic threshold. Repeated halothane anaesthetics at short intervals did not induce the reductive metabolism of halothane as assessed by 2-chloro-1,1,1-trifluoroethane (CTF) in the expired breath. One patient developed viral hepatitis A during the course of anaesthetic administration; this patient was the only one whose serum bromide concentrations fell substantially and whose exhaled CTF concentration increased as more anaesthetics were administered.

Adult↗

The significance of fat-filled macrophages in the diagnosis of aspiration associated with gastro-oesophageal reflux.

Tracheal aspirates from 46 children were examined for the presence of fat-filled macrophages. They had no history suggestive of gastro-oesophageal reflux. The number of positive results from this group (46%) was compared with the number of positive results (73%) in a group of 40 children with proven gastro-oesophageal reflux. The difference in proportion of positive results between the two groups was statistically significant (P less than 0.05). In addition, subgroups of subjects, negative for gastro-oesophageal reflux and lower respiratory tract disease, were compared with children who had both conditions. A slightly greater difference, although at a similar level of significance, was found. The fact that 42% of subjects without lower respiratory tract disease or gastro-oesophageal reflux had tracheal aspirates positive for fat-filled macrophages would, however, suggest that this test is of limited clinical value and may need better quantitation before it can be recommended for widespread clinical use.

Child↗

Quantities of Clostridium botulinum organisms and toxin in feces and presence of Clostridium botulinum toxin in the serum of an infant with botulism.

A 7-week-old boy presented with symptoms and signs characteristic of infant botulism, and the diagnosis was confirmed by the detection of Clostridium botulinum type A organisms and toxin in the feces. The levels of organisms and toxin in the feces were measured throughout the 81-day period in hospital. The maximum levels detected were 2.46 x 10(8) C. botulinum type A colony-forming units and 64,000 mouse 100% lethal doses of type A toxin per g (wet weight) of feces. C. botulinum toxin was also detected in two samples of the patient's serum, collected 3 and 10 days after admission. Improvement in the patient's clinical condition occurred before the levels of organisms and toxin in the feces reached their maxima. A slight improvement may also have occurred while toxin was still present in the serum.

Botulinum Toxins↗