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Biomedical subjects

D M Wilson

Publications and source records attributed to D M Wilson.

At least 361 records · Page 20Linked to original sources
PubMedDate not supplied

The interaction of dopamine, cocaine, and cocaethylene with ethanol on central nervous system depression in mice.

The interactions between dopamine, cocaine, cocaethylene, and ethanol were studied in Swiss-Webster mice. The loss of the righting reflex (LORR) was used as a measure of CNS depression. Animals were injected intraperitoneally (IP) with ethanol (4.0 g/kg). which caused a LORR. Immediately upon regaining of the righting reflex, mice were injected intracerebroventricularly (ICV) with saline, dopamine (0.1, 0.5, or 1.0 mumol/kg), cocaine (1, 15, or 25 mumol/kg), or cocaethylene (1, 15, or 25 mumol/kg). In the presence of systemic ethanol, all three compounds produced CNS depression in a dose-dependent manner. The dopamine D2-receptor antagonist sulpiride and the D1-receptor antagonist fluphenazine were given acutely ICV with dopamine in the presence of systemic ethanol to examine whether these antagonists could block the return to the LORR produced by dopamine. Sulpiride, however, actually enhanced the interaction between ethanol and dopamine in a dose-dependent manner as measured by the LORR; fluphenazine neither blocked nor enhanced the effect of dopamine in the presence of systemic ethanol. In addition, these antagonists had no effect on cocaine- and cocaethylene-induced CNS depression in the presence of systemic ethanol. The results of this study showed that the neurotransmitter dopamine and both cocaine and cocaethylene can promote further CNS depression in the presence of systemic ethanol, and that dopamine was significantly more potent than cocaine and cocaethylene as measured by the return to the LORR.

Animals↗
PubMedDate not supplied

Production of aflatoxins B1, B2, G1, and G2 in pure and mixed cultures of Aspergillus parasiticus and Aspergillus flavus.

Production of aflatoxins B1, B2, G1, and G2 in pure and mixed cultures of Aspergillus parasiticus and aspergillus flavus were compared. Differing percentages of A. parasiticus (NRRL 2999) and A. flavus (NRRL 5520) conidia were used as inoculum and allowed to grow in static liquid culture for 10 days. The pure and mixed cultures of A. parasiticus/A. flavus were extracted and the aflatoxins partially purified. High-performance liquid chromatography was then used to determine aflatoxin concentrations. The maximal decreases of G1 and G2 production occurred when the inocula went from 0 to 12.5% or 25% A. flavus. Aflatoxins G1 and G2 comprised less than 10% of the total aflatoxins when the A. parasiticus/A. flavus inocula contained greater than 25% A. flavus. Production of aflatoxins B1 and B2 increased slightly as the percentage of A. flavus in the A. parasiticus/A. flavus mixed inoculum increased. A. flavus is apparently capable of suppressing accumulation of aflatoxins G1 and G2 by A. parasiticus when these fungi are grown in mixed culture.

Aflatoxin B1↗
PubMedDate not supplied

Prediction of stone composition from plain radiographs: a prospective study.

BACKGROUND AND OBJECTIVES: Stone composition, as reflected in radiographic appearance, is important to help choose between SWL and percutaneous/endoscopic procedures. Predicting a stone's composition accurately from a plain radiograph would be a useful tool in clinical decision-making. However, the ability of physicians to predict composition has not been adequately assessed. A prospective study was designed to quantify the accuracy of a panel of physicians who routinely deal with stones in classifying stone composition solely from radiographs. MATERIALS AND METHODS: A panel of six members was created to review 100 plain-film radiographs from patients with renal stones of known composition. The panel consisted of two urologists, two radiologists, and two nephrologists, all of whom have expertise in stone disease. If the composition guessed was at least 40% of the total stone composition, the response was deemed correct. RESULTS: Overall, there was an average 39% correct response score among the six panelists. When the stones were divided by size, 35% were <1 cm, and 65% were larger. The accuracy of chemical composition determination did not improve with greater stone size, nor was there a difference in accuracy for pure and mixed stones. The most frequently misclassified stone was calcium phosphate, with only 14% being correctly diagnosed. CONCLUSIONS: With a random sampling of plain radiographs, a panel of physicians specializing in stone disease correctly diagnosed the composition of renal calculi less than half of the time without being given clinical information.

Calcium Oxalate↗
PubMedDate not supplied

Ultradian cardiac rhthms in surgical intensive care unit patients.

Several reports have suggested that heart rate may be regulated by an ultradian biological rhythm with a period of about 90--100 min. Blood pressure and heart rate were collected from 10 Surgical Intensive Care patients at 5-min intervals and analyzed by computer. No 90-min rhthms were found, indicating this rhythm has no significant influence on heart rate or blood pressure in postsurgical patients.

Adult↗
PubMedDate not supplied

Semi-automated entry of clinical temporal-abstraction knowledge.

OBJECTIVES: The authors discuss the usability of an automated tool that supports entry, by clinical experts, of the knowledge necessary for forming high-level concepts and patterns from raw time-oriented clinical data. DESIGN: Based on their previous work on the RESUME system for forming high-level concepts from raw time-oriented clinical data, the authors designed a graphical knowledge acquisition (KA) tool that acquires the knowledge required by RESUME. This tool was designed using Protégé, a general framework and set of tools for the construction of knowledge-based systems. The usability of the KA tool was evaluated by three expert physicians and three knowledge engineers in three domains-the monitoring of children's growth, the care of patients with diabetes, and protocol-based care in oncology and in experimental therapy for AIDS. The study evaluated the usability of the KA tool for the entry of previously elicited knowledge. MEASUREMENTS: The authors recorded the time required to understand the methodology and the KA tool and to enter the knowledge; they examined the subjects' qualitative comments; and they compared the output abstractions with benchmark abstractions computed from the same data and a version of the same knowledge entered manually by RESUME experts. RESULTS: Understanding RESUME required 6 to 20 hours (median, 15 to 20 hours); learning to use the KA tool required 2 to 6 hours (median, 3 to 4 hours). Entry times for physicians varied by domain-2 to 20 hours for growth monitoring (median, 3 hours), 6 and 12 hours for diabetes care, and 5 to 60 hours for protocol-based care (median, 10 hours). An increase in speed of up to 25 times (median, 3 times) was demonstrated for all participants when the KA process was repeated. On their first attempt at using the tool to enter the knowledge, the knowledge engineers recorded entry times similar to those of the expert physicians' second attempt at entering the same knowledge. In all cases RESUME, using knowledge entered by means of the KA tool, generated abstractions that were almost identical to those generated using the same knowledge entered manually. CONCLUSION: The authors demonstrate that the KA tool is usable and effective for expert physicians and knowledge engineers to enter clinical temporal-abstraction knowledge and that the resulting knowledge bases are as valid as those produced by manual entry.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Nicotine replacement combined with a novel compound (ProBAN) for smoking cessation: a pilot study.

BACKGROUND: Smoking cessation rates with available pharmacological therapies remain suboptimal. Anecdotal observations with a combination of sublingual pralidoxime and ipratropium (ProBAN) suggested that these agents in combination with nicotine gum improved quit rates. OBJECTIVE: To determine whether ProBAN together with nicotine replacement improves quit rates compared with nicotine replacement alone. DESIGN: A 12-week, prospective, double-blind, randomized, placebo controlled pilot study. SETTING: University-affiliated outpatient clinic. POPULATION STUDIED: Healthy adult smokers were recruited via advertisements. Of 107 subjects seen at the screening visit, 27 were excluded because of comorbid illness or concomitant medication use. INTERVENTIONS: Of 80 eligible subjects, 40 were randomly assigned to receive treatment with ProBAN sub- lingual tablets and nicotine gum (treatment group), and 40 to receive placebo tablets and nicotine gum (control group) for 12 weeks. The primary outcome was complete continuous abstinence of smoking from one through 12 weeks after the quit date. MAIN RESULTS: There were no adverse effects in the treatment group. At one week after the quit date, 35% of ProBAN-treated subjects had quit compared with 18% of control subjects (odds ratio [OR] 2.5, 95% CI 0.9 to 7.2). Corresponding quit rates at four weeks were 28% and 15% (OR 2.1, 95% CI 0.7 to 6.5), at eight weeks were 25% and 13% (OR 2.3, 95% CI 0.7 to 7.6), and at 12 weeks were 23% and 13% (OR 2.0, 95% CI 0.6 to 6.7), respectively. CONCLUSIONS: This pilot study indicated that ProBAN combined with nicotine replacement doubled the continuous sustained quit rate compared with nicotine replacement alone, with no adverse effects. Although not statistically significant due to the size of the study, this result suggests that it may be an effective therapy for smoking cessation, and larger studies are warranted.

Administration, Sublingual↗
PubMedDate not supplied

Histologic lesions associated with intravenous infusions of large volumes of isotonic saline solution in rats for 30 days.

The objective of this study was to characterize the changes associated with intravenous infusions of large volumes of isotonic saline solution in rats so that effects of the infusion process could be more easily distinguished from effects of test articles. Male Sprague-Dawley rats weighing approximately 225-275 g at the beginning of the study were given intravenous infusions of isotonic saline solution once daily for 30 consecutive days at dosages of 40 or 80 ml/kg body weight. Saline solution was administered through catheters placed in the caudal veins of the tail according to one of the following regimens: 80 ml/kg at 0.25 ml/min; 80 ml/kg at 0.5 ml/min; 80 ml/kg at 1.0 ml/min; and 40 ml/kg at 1.0 ml/min. Control rats were catheterized but not administered intravenous fluids. One day following the last treatment, all rats were necropsied and major organs were collected in 10% formalin. Histologic lesions associated with treatment included increased incidence and severity of pulmonary periarterial infiltrates of eosinophils, multifocal pulmonary inflammation, pulmonary granulomas that often contained hairshaft fragments, endothelial hypertrophy and hyperplasia within pulmonary arterial vessels, and pulmonary arterial medial thickening. Infiltrates of eosinophils around small pulmonary arteries were more severe in rats given intravenous infusions than in untreated rats and were more severe in rats given isotonic saline at the 80-ml/kg dosage than at the 40-ml/kg dosage. The severity of periarterial infiltrates of eosinophils increased with increasing infusion rates in rats that received 80 ml/kg isotonic saline. Pulmonary granulomas and multifocal pulmonary inflammation were observed in more rats that received intravenous saline than in control rats, but their incidences did not appear to vary with the volume or rate of infusion. Multifocal endothelial hypertrophy and hyperplasia occurred in most rats given isotonic saline solution at all volumes and rates, but not in untreated control rats. Inflammatory lesions in the tail near the injection site were considered sequellae of catheter insertion that, in some instances, may have been exacerbated by intravenous saline infusion. There were no lesions in other organs that were attributable to intravenous infusions of isotonic saline solution.

Animals↗
PubMedDate not supplied

Educational video game for juvenile diabetes: results of a controlled trial.

Packy & Marlon, an interactive video game designed to improve self-care among children and adolescents with diabetes, was evaluated in a six-month randomized controlled trial. In the game, players take the role of animated characters who manage their diabetes by monitoring blood glucose, taking insulin injections, and choosing foods, while setting out to save a diabetes summer camp from marauding rats and mice who have stolen the diabetes supplies. Study participants were patients aged 8 to 16 from two separate diabetes clinics. Each participant received a Super Nintendo video game system at an initial clinic visit and was randomly assigned to receive either Packy & Marlon (treatment group, N = 31) or an entertainment video game containing no diabetes-related content (control group, N = 28). Participants were interviewed and a parent filled out a questionnaire at baseline, three months, and six months. The findings in this study indicate that well-designed, educational video games can be effective interventions. There was improvement in the treatment group relative to the control group in terms of diabetes-related self-efficacy (p = 0.07), communication with parents about diabetes (p = 0.025), and self-care behaviours (p = 0.003), and a decrease in unscheduled urgent doctor visits (p = 0.08). There were no significant differences between the groups in knowledge about diabetes or in glycated haemoglobin (HbA1c) levels. Since participants in the study were in general well-controlled patients who were receiving excellent medical care, future research is contemplated involving youngsters who are not under good glycaemic control.

Adolescent↗
PubMedDate not supplied

A family physician smoking cessation program: an evaluation of the role of follow-up visits.

Our purpose in this randomized clinical trial was to compare a two-visit smoking cessation intervention by family physicians with the same intervention supplemented by additional follow-ups. Forty-one southern Ontario family physicians volunteered for the study and subsequently participated in a four-hour training program on smoking cessation techniques. Physicians advised patients who smoked and indicated an interest in attempting to quit with the help of their physician to stop smoking at the end of a regularly scheduled visit. Physicians instructed patients to make a specific appointment for an evaluation of their smoking habits. Six hundred forty-seven patients returned for that assessment and were than randomized into either the two-visit intervention group (with risk assessment, support, the setting of a cessation date, self-help literature, and a prescription for nicotine gum, where appropriate) or into the other intervention group (with the same maneuvers as well as the offer of four more supportive follow-up visits). We found no statistically significant difference in one-year, biochemically validated, sustained cessation rates between the group offered the long-term follow-up visits (12.5%) and the group given the brief intervention (10.2%). The 95% confidence interval on the difference between the groups was 2.8% in favor of the brief intervention group to 7.3% in favor of the group offered follow-up. The results do not support the value of long-term follow-up visits for smokers.

Adult↗
PubMedDate not supplied

Patients' perspectives of a physician-delivered smoking cessation intervention.

Forty-three patients--recipients of a highly structured, physician-delivered smoking cessation intervention--were interviewed using ethnographic (anthropological) research methods. We conducted interviews with patients after visits with the physician, then audiotaped and transcribed them. Discourse analysis of interview texts identified features and components of the physician maneuver most effective from the patients' point of view. Patients discussed two general areas of physicians' preventive activities: an interventionistic component (in which professional, diagnostic, and authoritative features were emphasized) and a personalistic component (in which physicians were experienced as equals, supportive, caring, empowering, and challenging). From the perspective of patients, the personalistic component of the physician-delivered smoking cessation maneuver appeared most effective. We conclude that, in clinical preventive medicine generally, patients (1) evaluate the kind of support they receive from their physician (e.g., degree of empathy, encouragement, and sincerity), (2) respond favorably to positive imagery in the challenge to alter their lifestyle, (3) look for a balance in the relationship established with their physician (negotiation, respect, mutual understanding, and rapport), and (4) remember the consistency and regularity of their physician's health promotion messages.

Female↗
PubMedDate not supplied

Comparison of postcolumn derivatization-liquid chromatography with thin-layer chromatography for determination of aflatoxins in naturally contaminated corn.

Quantitation of aflatoxins by liquid chromatography with postcolumn iodine derivatization (LC-PCD) and fluorescence detection was compared with quantitation by the AOAC CB method, 968.22. Thirty-seven naturally contaminated corn samples were ground and then divided. One portion was extracted, and the extract was cleaned up and analyzed by thin-layer chromatography according to the CB method. The second portion was extracted and cleaned up in a similar fashion, but quantitation was by the LC-PCD method. For aflatoxin B1 concentrations ranging from 0 to 150 ng/g, results obtained by the 2 methods were fitted to a linear equation with the LC-PCD results as the dependent variable. The correlation coefficient was 0.99, the intercept was near 0, and the slope was near 1. For aflatoxin B2, the correlation coefficient was 0.97, and the intercept was near 0. However, the slope of the equation relating LC-PCD concentration to TLC concentration was only 0.5. We believe that this lack of equivalence between the methods for determination of aflatoxin B2 is due to overestimation by the TLC method because the low levels present are near the TLC detection limit for B2.

Aflatoxin B1↗
PubMedDate not supplied

Fluorometric screening method for citrinin in corn, barley, and peanuts.

A fluorometric method is described for rapid screening of citrinin in corn, barley, and peanuts. The initial extraction uses an aqueous acidified acetonitrile solution, and the resulting extract is partially purified by several acid-base partition steps. Citrinin is determined by using a fluorometer. Mean recoveries of added citrinin from corn, barley, and peanuts were 56.4, 66.6, and 40.0%, respectively, at levels of 100-8000 ng/g.

Arachis↗