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Biomedical subjects

J G Crowder

Publications and source records attributed to J G Crowder.

At least 19 recordsLinked to original sources
PubMed1995

Determination of anaesthetic agent concentration by refractometry.

Reference refractivity values have been derived for the anaesthetic agents halothane, isoflurane, enflurane, sevoflurane and desflurane which are traceable to national measurement standards. A simple method and equation have been derived for the application of these data to the measurement of agent concentration by refractometry. The main instrumental sources of uncertainty associated with this method are discussed and their respective contributions quantified. Agent concentration can be measured routinely at the +/- 1% level of uncertainty using this approach.

Anesthetics, Inhalation↗
PubMed1994

The evaluation of interactions between anaesthetic agent vapours and carrier gases by laser refractometry.

A measurement system and technique have been developed for the evaluation of interactions between anaesthetic agent vapours and carrier gases. The refractivities of mixtures of anaesthetic agent and carrier gas have been compared to values derived from the addition of the absolute refractivities of the individual components. These results show that there is no significant interaction between the anaesthetic agent and the carrier gas at the +/- 0.06% level of uncertainty. Results for the anaesthetic agents isoflurane, sevoflurane, enflurane, halothane, chloroform and desflurane and the carrier gases nitrogen, oxygen and dry air will be presented.

Anesthetics, Inhalation↗
PubMed1976

Propionibacterium acnes: pathogen in central nervous system shunt infection. Report of three cases including immune complex glomerulonephritis.

Propionibacterium acnes is a pleomorphic gram-positive anaerobic rod usually isolated as a contaminant from skin. We report three cases of P. acnes infection of central nervous system shunts for hydrocephalus. The organism was seen repeatedly on gram stain in a specimen of shunt fluid in all three cases; initially, it was regarded as a contaminant. In addition, two of the patients had precipitins to extracts of their organism. Serum from normal control subjects had no such precipitins. One of the patients had an immune-complex glomerulonephritis--an entity not previously associated with anaerobic organisms. All three patients recovered after removal of the shunt and treatment with antibiotics. P. acnes is a significant pathogen in patients with central nervous system shunts.

Adolescent↗