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Biomedical subjects

C Warren

Publications and source records attributed to C Warren.

At least 73 records · Page 4Linked to original sources
PubMed1987

Oral cholecystography and sonography of gallbladder in cholecystectomy patients.

In comparing the diagnostic specificity and sensitivity of oral cholecystography with that of sonography in 479 patients in a community hospital, the oral cholecystogram, when used with a double dose of contrast agent, showed greater specificity (1.00) and sensitivity (0.99) than the sonogram (0.54 and 0.94, respectively). Because of lower cost, the oral cholecystogram should be used as the initial diagnostic study when cholelithiasis is suspected, unless specific contraindications exist.

Adolescent↗
PubMed1986

A comparison of the homogeneous enzyme immunoassay (EMIT) autocarousel and quantitative single test (QST) systems with the radioenzymatic assay.

A comparison was made of three methods for gentamicin assay; a modification of the radioenzymatic transferase technique, which was used as the reference method; EMIT autocarousel; and EMIT quantitative single test (QST). Correlation of both EMIT systems with the radioenzymatic method and with each other gave acceptable correlation coefficients, 0.955-0.975, for the range of concentrations tested. The coefficients of variation for within assay studies were between 3.3 and 4.9 for all three methods. Both EMIT systems provided rapid results, within minutes, albeit at a higher cost than the radioenzymatic assay. The radioenzymatic technique although cheaper with regard to the cost of materials involves considerably more technical time and effort and might not be considered suitable for samples received out-of-hours. However the combination of both EMIT systems provides facilities for batch and one-off sample tests and the ease of operation and rapid results are suited to out-of-hours operation.

Costs and Cost Analysis↗
PubMed1986

Macrolide, lincosamide and streptogramin resistance in Campylobacter jejuni/coli.

Strains of erythromycin-resistant Campylobacter jejuni/coli isolated in the United Kingdom, Canada and Europe, were also resistant to tylosin, spiramycin and clindamycin and, like sensitive strains, were insensitive to virginiamycin and pristinamycin component B. These were designated as macrolide-lincosamide-streptogramin generalized resistant organisms and macrolide-lincosamide generalized resistant on the basis of patterns of resistance to pristinamycin components A and B. Two erythromycin-sensitive strains whose resistance to spiramycin and tylosin had been produced in the laboratory showed cross resistance to erythromycin, but were still sensitive to clindamycin. These were characterized as macrolide-streptogramin A inducible resistant organisms. The isolates tested were identified and all were found to be C. coli, except for two strains, one erythromycin-resistant and one erythromycin-sensitive, which hydrolyzed hippurate and were thus identified as C. jejuni.

Anti-Bacterial Agents↗
PubMed1984

Monitoring of somatosensory evoked responses during carotid endarterectomy.

During carotid endarterectomy (CEA), we monitored somatosensory evoked responses (SERs) ipsilaterally over the scalp following stimulation of the contralateral median nerve at the wrist. Thirty-eight CEAs in 36 patients were studied. Of the 10 CEAs performed with patients under general anesthesia, three involved marked changes in SERs, reversed by shunt insertion. The remaining 28 CEAs were done with patients under local anesthesia. The SERs remained stable during an average clamp time of 30 minutes in all except one patient, in whom SER changes developed within a minute of clamping; the changes were reversed by shunt placement. Four of the 38 CEAs required a shunt based on SER changes, although measurement of stump pressure (less than 50 mm Hg) would have indicated the necessity of a shunt in eight additional operations. We concluded that SERs are useful in signaling cerebral ischemia and the need for a shunt during CEA.

Aged↗
PubMed1983

Evoked response studies in patients with adrenoleukodystrophy and heterozygous relatives.

Brain-stem auditory evoked responses (BAERs) and somatosensory evoked responses (SERs) were studied in three patients and seven female relatives in three families with adrenoleukodystrophy (ALD). All patients with ALD had abnormal BAERs and SERs, reflecting the central demyelination occurring in ALD. Four of the seven female family members had abnormalities of SERs with or without abnormalities of BAERs, similar to those seen in the patients. We suggest that these abnormalities demonstrate the morphological effects of the ALD gene in the CNS and reflect the physiological alteration in the heterozygous females in families with ALD.

Adolescent↗
PubMed1983

Cefotetan: in-vitro antibacterial activity and susceptibility to beta-lactamases.

The in-vitro antibacterial activity of cefotetan was assessed against recent clinical isolates of common bacteria and also against reference strains that produced known beta-lactamases. The compound was active against most staphylococci (MICs 4 to 8 mg/l) though methicillin-resistant strains were less sensitive. It was also generally active against streptococci (MICs mostly in the range 1 to 16 mg/l). However, enterococci and penicillin-resistant pneumococci were resistant. Cefotetan was highly active against enterobacteria, with 75% of isolates inhibited by 0.5 mg/l and 90% inhibited by 4 mg/l. It was also highly active against Haemophilus influenzae (MICs 0.5 to 4 mg/l) and Neisseria gonorrhoeae (MICs 0.06 to 2 mg/l) but had relatively poor activity against Acinetobacter spp. (MICs mostly 4 to 128 mg/l). Cefotetan had little useful activity against Pseudomonas aeruginosa (MICs 16 to 512 mg/l) but was more active against most other pseudomonads. Cefotetan had moderate activity against the Bacteroides fragilis group (MICs mostly less than or equal to 32 mg/l), though Bact. fragilis sensu stricto and Bact. vulgatus were more sensitive (MICs usually less than or equal to 4 mg/l). It was more active against most other anaerobes, though its activity was always exceeded by that of ampicillin. Cefotetan possessed a high degree of resistance to both plasmid-mediated and chromosomally-determined beta-lactamases.

Anti-Bacterial Agents↗
PubMed1982

Brain stem auditory, visual and somatosensory evoked potentials in leukodystrophies.

Brain stem auditory (BAERs), visual (VEPs) and somatosensory evoked responses (SEPs) were recorded in 12 patients with Pelizaeus-Merzbacher leukodystrophy (PMD), three with adrenoleukodystrophy (ALD) and three with metachromatic leukodystrophy (MLD). All the 3 evoked responses were abnormal in all patients except normal VEPs and SEPs in a patient with early ALD. In most patients wave I with and without wave II were the only components of the BAERs that remained, subsequent components (waves III-VII) were absent. VEPs were severely altered; either no identifiable response to flash or pattern reversal stimuli could be recorded or the major components were significantly delayed in latency. Short latency SEPs following median nerve stimulation usually showed a normally recorded Erb's potential (N10), but an absence or marked attenuation of cervical (N14) and early scalp components (N19 and P22) or the occurrence of the scalp components with a significant delay. Multimodality evoked responses provide more information regarding the functional integrity of several afferent systems in patients with white matter disorders.

Acoustic Stimulation↗
PubMed1982

The effects of priming on picture recognition.

In two experiments we show that the prior presentation of a picture serves to facilitate the recognition of that picture in a tachistoscope up to 45 minutes later. Facilitation of recognition also occurred with prior presentation of a different picture with the same name. This cannot be explained items of a response bias, since the presentation of a word, which the subject read aloud, had no effect whatsoever upon the subsequent recognition of the picture. The data are interpreted in terms of a categorization stage for pictures which is completely independent of the verbal system. Data from other experimental paradigms are also examined. Our categorization model enables consistent interpretation of these data, which otherwise appear contradictory.

Discrimination Learning↗
PubMed1982

In vitro antibacterial activity of norfloxacin (MK-0366).

The in vitro activity of norfloxacin (MK-0366) compared with that of beta-lactam antibiotics and, where appropriate of gentamicin or metronidazole was assessed against recent clinical isolates of common bacteria. The compound was highly active against most enterobacteria (minimal inhibitory concentrations [MICs], 0.008 to 32 micrograms/ml; 90% inhibited by 0.25 micrograms/ml), Haemophilus influenzae (MICs, 0.03 to 0.12 micrograms/ml), and Neisseria gonorrhoeae (MICs, 0.008 to 0.016 micrograms/ml). It was also active against Pseudomonas aeruginosa (MICs, 0.12 to 2 micrograms/ml), most other pseudomonads (MICs, 0.03 to 32 micrograms/ml), and Acinetobacter calcoaceticus (MICs 0.06 to 4 micrograms/ml). Norfloxacin was somewhat less active against staphylococci (MICs, 0.25 to 4 micrograms/ml; 1 microgram/ml required to inhibit 50% of isolates) and streptococci (MICs, 0.5 to 64 micrograms/ml). Members of the Bacteroides fragilis group of anaerobes were relatively resistant to norfloxacin (MICs, 8 to 128 micrograms/ml), as were most other anaerobes.

Aerobiosis↗
PubMed1982

Serum concanavalin-A binding in rheumatoid arthritis.

A nephelometric assay of concanavalin-A binding of serum acute phase proteins (con-A binding) has been used in cross-sectional and sequential studies of disease activity in rheumatoid arthritis (RA). Con-A binding correlated well with blood viscosity, C-reactive protein, and other individual acute phase reactants in patients with active RA. Twenty-four patients were treated for 6 months with D-penicillamine and assessed clinically and seriologically. Clinical improvement was accompanied by significant falls in both C-reactive protein and con-A binding, although the serological changes did not always occur in parallel in individual patients. The advantages of this simple, cheap assay of acute phase proteins are discussed.

Adolescent↗