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Biomedical subjects

A Lee

Publications and source records attributed to A Lee.

At least 19 recordsLinked to original sources

Haemagglutination profiles of Helicobacter species that cause gastritis in man and animals.

Thirty-five Helicobacter pylori isolates, 21 H. mustelae isolates and four strains of H. felis were compared for their ability to agglutinate red blood cells (RBCs). Isolates were examined in a slide haemagglutination assay with RBCs from 11 animal species, including rodents, carnivores and primates, as well as man. RBCs were agglutinated by 65-90% of H. mustelae isolates and 16-57% of H. pylori isolates. Treatment of H. mustelae with pronase and heat inhibited haemagglutination (HA) whereas heating only of H. pylori inhibited HA. Treatment of all strains of H. mustelae with trypsin inhibited agglutination of human RBCs; 75% of the treated strains did not agglutinate ferret RBCs. These results suggested that protein(s) may be important haemagglutinins for these bacteria. Variable HA profiles together with varying results after treatment of RBCs with fetuin, D-mannose, and neuraminidase suggested that multiple receptors may be involved in HA reactions with H. pylori and H. mustelae. The observation that H. mustelae and H. pylori agglutinated RBCs of several species and closely adhered to gastric epithelium supported the hypothesis that adherence plays a role in the colonisation and pathogenicity of H. mustelae and H. pylori. H. felis did not adhere to gastric epithelium and did not agglutinate RBCs of any species; nevertheless, H. felis can readily colonise and produce gastritis in several mammals.

Animals

Consumer survey on microbiology reports.

5 typical microbiology reports were circulated to the medical staff of a 900-bed teaching hospital and they were asked for their interpretations. Approximately 160 completed replies were received and it was clear that the reports were often misinterpreted; one report (isolation of a gram-negative rod from sputum) was misinterpreted by four doctors out of five. The reasons for this failure of communication seem to be the use of jargon and unfamiliar names of bacterial species, and use of ill-defined reporting conventions. The omission of a clear-cut conclusion from many reports also contributed to misunderstanding. These deficiencies in reporting practices result in unnecessary antibiotic therapy and unnecessary work for the laboratory, since clinicians are more likely to ask for a repeat of a test with a doubtful interpretation. Communications with clinicians would be more effective if microbiologists ensured that each report is free of jargon, states what conclusion can be drawn from the test, and makes recommendations, where appropriate, for antibiotic therapy.

Aged

The preservation of surface-associated micro-organisms prepared for scanning electron microscopy.

Scanning electron microscopy (SEM) has become a popular means of studying micro-organisms which associate with surfaces. However, as yet no detailed examination has been made of the influence of specimen preparation on the number of organisms finally seen on the SEM screen. In this investigation critical assessment is made of the influence of a wide range or preparative factors on the preservation of filamentous bacteria associated with the epithelial surfaces of rat intestine. Organisms were quantitated using a rigorous counting method (transect line analysis); statistical testing of these counts enabled the comparison of different preparative factors. The composition of the fixative was found to significantly influence the number of organisms preserved; of the fifteen fixatives studied, Karnovsky's fixative with ruthenium red best preserved surface-associated organisms. The influence of other factors on the number and appearance of preserved organisms was also examined. These factors included the washing of specimens prior to fixation, the storage of fixed specimens, and the handling and storage of critical point dried specimens. The results are discussed with reference to the optimal methods for preparing specimens for SEM.

Animals

Effects of maternal drinking on neonate state regulation.

Sleep-awake state distribution during inter-feed intervals over a 24-hour period on the third day of life was investigated by means of a continuous non-intrusive bassinet sleep monitor. 31 infants were studied: 14 born to mothers who drank heavily throughout pregnancy (group A), eight whose mothers modified their heavy drinking (group B) and nine whose mothers never were heavy drinkers (group C). Over the 24-hour period, group A infants slept less than those in group B. In comparison with group C, group A infants had a larger proportion of quiet sleep episodes interrupted by awake or unclassified epochs, and were more restless, with more frequent major body movements. These pilot observations suggest that heavy maternal consumption of alcohol, when continued throughout pregnancy, is associated with a disturbance of sleep-awake state distribution. Successful therapy of heavy drinking during pregnancy may improve the physiological competence of the newborn to regulate sleep-awake states and facilitate interaction between mother and infant.

Adolescent

Once daily propranolol in the treatment of mild to moderate hypertension: a dose range finding study.

Propranolol was administered in a single dose of 80 mg, 120 mg, 160 mg, 240 mg, or 320 mg, to 23 patients with essential mild to moderate hypertension in a randomised, double-blind cross-over study. All treatments produced a significant fall in lying and standing blood pressures compared with placebo, but there was no statistically significant difference in the effects of the different doses. The percentage of patients showing a satisfactory fall in blood pressure was not different in the five treatment groups. The major anti-hypertensive effect of each dose was present by two weeks. The frequency of side-effects were similar on all the doses.

Adult

The mucosa-associated microflora of the rat intestine: a study of normal distribution and magnesium sulphate induced diarrhoea.

Specimens of intestinal mucosa of rats were examined closely to determine the distribution of the mucosa-associated microbial flora. Six distinct zones were found along the length of the intestinal tract. The first zone, in the small intestine 50 cm or more from the ileocaecal junction, had no associated flora: however, each of the five other zones had different populations of microorganisms associated with the mucosa. Some of these organisms have not been reposted previously. Treatment of rats with oral doses of the purgative magnesium sulphate resulted in dramatic changes in the distribution of these mucosa-associated microorganisms. The normal flora of ileal and caecal crypts disappeared, while the organisms in colonic crypts were unchanged. Large numbers of mucosa-associated bacteria appeared in the stools of treated animals.

Animals