Biomedical subjects
Publications and source records attributed to G R Stephenson.
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A method for the characterization of flavanones in fruit juices, involving solvent extraction, hydrolysis to the corresponding aglycones, trimethylsilylation and combined gas chromatography-mass spectrometry, is reported. The application of the method is demonstrated for the analysis of orange, lemon, grapefruit and grape juices.
Total body dose received in home gardeners applying 2,4-D and bystanders living within the household, but not applying the pesticide was measured. Levels of 2,4-D were monitored in air samples both inside the home and downwind of the application site. Homeowners were divided into protective and non-protective apparel groups and applied both a granular and liquid formulation of 2,4-D on two separate dates. Analyses of urine collected from homeowners for 96 hours following applications found total body doses ranging from non-detectable to 0.0071 mg/kg of body weight. The highest exposures occurred in the non-protected group and were consistently associated with spills of the liquid concentrate or excessive contact with the dilute mixture on the hands or forearms. Residues of 2,4-D were not detected in urine samples supplied by bystanders to home applicators. Residues of 2,4-D were detected in five of the 76 air samples taken during the home applications. Two of these air samples coincided with measurable applicator exposure but it is unlikely that this was a major route of exposure.
This study examined four aspects of mothers' working models of infant feeding: (1) infant behaviour that cues feeding decisions; (2) infant self-regulative behaviour; (3) importance of infant self-regulative behaviour and maternal effort directed to it; and (4) maternal effort and value given to task-oriented and efficient feeding. The relation of these aspects to maternal experience, age, formal education, family income, and feeding method was also explored. Subjects were 122 mothers of healthy, term infants between 14 and 60 days old. A telephone interview obtained demographic and attribute data and assessed the four aspects with 30 scaled items. Crying before and sleepiness during feeding were relatively compelling cues for maternal action. Most mothers gave only moderate ratings to the importance of infant self-regulative behaviour and to task-oriented and efficient feeding. Parity and feeding method affected response to specific items, with primiparae more concerned about length and regularity of feedings. Mothers who bottle-fed their infants were more concerned about maintaining a feeding once initiated than mothers who breast-fed their infants. Four-factor analysis yielded two item clusters with good internal consistency: Cluster a. Maternal Effort to Accomplish Feeding Goals; and Cluster b. Importance of Infant Self-Regulative Behaviour. Cluster a. and b. were strongly correlated. Feeding method influenced both clusters, and the interaction of parity and feeding method had an effect on Cluster a. Mothers with lower family income had higher scores on Cluster b; multiparae with lower family income on Cluster a. How and when infant self-regulation develops as a goal is a question in need of study.
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In the examination of stream waters for fecal coliforms, pale yellow colonies regularly appeared on m-FC broth base medium plates. The yellow colonies may comprise 70% more of the colonies of an m-FC plate. More than 80% of these colonies were identified as Escherichia coli by the API 20E identification system and by serotyping. The atypical yellow E. coli strains were not environmentally stressed E. coli since the atypical colonies continued to be yellow on m-FC medium after growth in a nonselective medium. However, 50% of the atypical E. coli strains were o-nitrophenyl-beta-D-galactopyranoside positive, and 20% produced gas in EC medium at 44.5 degrees C. Failure to consider these atypical E. coli strain in water quality analyses could lead to a significant error in the estimation of water quality in some instances.
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PURPOSE: To determine whether fibrin sealant injected into the tract created by liver biopsy can be used to decrease postprocedural bleeding. An innovative delivery system was used to deploy the fibrin sealant. MATERIALS AND METHODS: Fibrin sealant is a hemostatic agent consisting of a suspension of fibrinogen and thrombin. A delivery system was devised whereby fibrin sealant could be injected into the tract created by liver biopsy. Thirty swine were randomized into three groups: control (n = 10), heparin (n = 10), and warfarin (n = 10). Each swine underwent laparotomy and was randomized to undergo three to five open liver biopsies with either a 14-gauge cutting needle in conjunction with the fibrin sealant device or a standard 14-gauge cutting needle alone. Forty-seven biopsy procedures were performed with the device; 64 biopsy procedures were performed without the device. Immediate blood loss per biopsy (mL) was estimated based on the size of the blood stain on a sponge. Specimens were assessed for sample size. RESULTS: Immediate blood loss with and without the device, respectively, was: control, 0.1 mL, 5.4 mL; heparin, 0 mL, 7 mL; warfarin, 0.1 mL, 9.3 mL. These differences were significant (P < .01) for each group of swine. In 43 of 47 biopsies (91%), the device functioned without difficulty. There was no difference in sample size when the device was used. CONCLUSIONS: The fibrin sealant device is effective in reducing bleeding after open liver biopsy in anticoagulated and nonanticoagulated swine. The promising results suggest that a trial of percutaneous liver biopsy in swine should be considered.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A generalizable, computerized method has been designed to describe in detail interactive events that occur within phases of a process involving two or more interactants. The objectives of the method are: (A) visual discernment of patterns of events within and across phases through graphically displayed data and (B) summarization of events within phases for comparison of events across phases. Stages of the implementation of these objectives are illustrated with data obtained from observations of mother-infant feeding interaction. The method provides a means for an investigator to structure the exploration of patterns of behaviors in the context of the social activity in which the behaviors occur and to develop hypotheses about the data.