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C Arnold

Publications and source records attributed to C Arnold.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Predictive modelling of fluorescent AFLP: a new approach to the molecular epidemiology of E. coli.

Amplified fragment length polymorphism (AFLP) permits simultaneous sampling of multiple loci distributed throughout a genome, using restriction site/adaptor-specific primers under stringent conditions. Fluorescent detection instrumentation further refines this methodology, permitting internal size standards and accurate, reproducible sizing of amplified fragments. We have evaluated the potential of fluorescent AFLP (FAFLP) as a potentially definitive genotyping method for bacteria, by comparing MseI/EcoRI fragments derived experimentally from the Escherichia coli K12 MG1655 genome with those predicted by analysis of its published sequence. In silico, MseI/EcoRI digestion of this sequence produced 1200 fragments from 36 and 2151 base pairs (bp) in size. Fragment subsets which would be amplified by seven different selective (1-2 bases added to the 3' end of the core primer sequence) primer combinations were modelled. Depending on the primer pair, three to 54 fragments (range 70-400 bp) were predicted, while all seven primer pair combinations together generated 121 predicted fragments. When genomic DNA of strain MG1655 was subjected to experimental FAFLP with these seven primers, 111 correctly sized fragments were observed (+/- 1 bp) out of the 121 predicted (92% accuracy). Twenty-five unpredicted fragments were obtained; an average of four per primer pair. The size and number of fragments in FAFLP, and their gel distribution, were dictated by the choice of restriction endonucleases and the degree of primer selectivity. Our data show that FAFLP is accurate, discriminatory, reproducible and capable of standardisation. Under agreed conditions, this method shows considerable promise as a generally applicable standardised bacterial genotyping method. The fragments predicted in silico to result from amplification of MseI/EcoRI-digested DNA with the seven primer pairs described are here used to define a prototypic FAFLP analysis of E. coli.

Escherichia coli↗
PubMedDate not supplied

Comparison of gastrointestinal tolerance to two enteral feeding protocols in critically ill patients: a prospective, randomized controlled trial.

BACKGROUND: The purpose of this study was to compare gastrointestinal tolerance to two enteral feeding protocols in critically ill patients. METHODS: A prospective, randomized controlled trial, that involved 96 consecutive patients expected to stay in the intensive care unit for > or =3 days and who had no contraindications to enteral feeding. The patients were randomized to either the current protocol (group I; gastric residual volume threshold, 150 mL, optional prokinetic) or proposed feeding protocol (group II; gastric residual volume threshold 250 mL, mandatory prokinetic). Gastrointestinal intolerance was recorded as episodes of high gastric residual volume, emesis, or diarrhea. The time to reach the goal rate of feeding and the percentage of nutritional requirements received during the study period were also recorded. RESULTS: Nineteen of 36 patients (19/36 = 0.53) in group I had one or more episodes of high gastric residual volume, compared with 10 of 44 patients (10/44 = 0.23) in group II (p < .005). There was no statistical difference between the two protocols with regards to emesis, diarrhea, or the total episodes of intolerance. The patients in group II reached their goal rates on average in 15 hours and received 76% of their nutritional requirements, compared with 22 hours and 70% in group I; however, these differences were not statistically significant. CONCLUSIONS: The incidence of enteral feeding intolerance was reduced by using a gastric residual volume of 250 mL along with the mandatory use of prokinetics. The study showed a trend of improved enteral nutrition provision and reduced the time to reach the goal rate in group II. These improvements support the adoption of the proposed feeding protocol for critically ill patients.

Adult↗