Computer-based simulations enhance clinical experience of dietetics interns.

OBJECTIVE: To determine the impact of computer-based simulations on the performance of dietetics interns in initial clinical rotations. DESIGN: Interns used either a simulation program (Care Planning Simulation System CPSS[) or a computer-based tutorial (Nutrition Care Planning Tutorial NCPT[) during their orientation. Performance of these interns on nutrition care skills was evaluated during their initial clinical rotations. SUBJECTS/SETTING: Participants were 108 dietetics interns from 8 different programs. Each internship had at least 8 interns, and none of the internships awarded a graduate degree. INTERVENTION: Subjects in the experimental group completed nutrition assessment and care planning activities for 3 simulated patients. Subjects in the control group completed a tutorial on assessment and care planning. MAIN OUTCOME MEASURES: Likert scale ratings of 31 behaviors were recorded by clinical preceptors. Behavior statements were grouped into 8 categories and average ratings for each category were determined. STATISTICAL ANALYSIS: Repeated-measures analysis of variance and linear regression were used to compare performance ratings between groups. RESULTS: There were no differences in overall evaluations of the simulation and tutorial groups for the 8-week period. Interns who started clinical rotations immediately after orientation (CPSS-I and NCPT-I groups) were rated lower in all categories than those who began their clinical rotations later (CPSS-D and NCPT-D groups). Maturation and acquisition of general skills likely influenced ratings of interns with delayed clinical rotations. For most categories of behavior the rate of improvement in rating scores was greatest for interns who used CPSS. APPLICATIONS: Computer-based simulations are a promising supplement to current techniques in didactic instruction and may be useful in both didactic and practice settings. Computer-based simulations can provide more varied practice experiences to didactic students and interns in preparation for more skilled entry-level positions in dietetics.

Computer-assisted instruction improves clinical reasoning skills of dietetics students.

OBJECTIVE: The effects of a computer-assisted instruction (CAI) tutorial program on learning clinical reasoning skills were compared in undergraduate dietetics students. DESIGN: A drill-and-practice program to control for time on task, and tutorial program, and a simulation program, as the test vehicle, were developed. The tutorial and simulation programs presented data on a patient with cardiovascular disease. SETTING: Subjects were tested in 30 undergraduate dietetics programs. SUBJECTS: Participants were 413 undergraduate diet therapy students enrolled in a coordinated program in dietetics (CPD) or a didactic program in dietetics (DPD). INTERVENTION: After completion of lectures on cardiovascular disease, subjects were given the drill-and-practice program plus a simulation test (group 1), the tutorial plus a simulation test (group 2), or the simulation test only (group 3). MAIN OUTCOME MEASURES: Scores on the simulation test were compared. Variables included type of CAI, dietetics program, year in school, computer experience, and experience using a medical chart. Mastery of objectives related to lower- and higher-level clinical reasoning skills introduced in the tutorial program was computed. STATISTICAL ANALYSIS: One-way analysis of variance and Student-Newman Keuls tests were conducted to determine any differences among the three groups. Reliability was determined using the Kuder-Richardson Formula 20. RESULTS: The reliability coefficient of the stimulation test was 0.93. Group 2 higher on the simulation test than group 1 or group 3. As a group, the CPD students scored higher than the DPD students. When CPD and DPD students were divided into the three experimental groups, there was no significant difference between the CPD and DPD student simulation scores. Group 2 mastered all objectives for lower-level reasoning skills and the higher-level decision-making objective better than groups 1 and 3. APPLICATIONS/CONCLUSIONS: A computer tutorial program enhanced clinical reasoning skills in undergraduate dietetics students. This type of program could be used to supplement many topics taught in diet therapy and provide DPD students with experimental learning before their clinical intern practicums.

Effect of nicotinamide on drug metabolizing enzymes in the neonatal rat.

Sprague-Dawley rats were raised by dams (mother reared, MR) or artificially reared from day 4 to day 11, using chronic intragastric cannulas, and infused with one of four diets: control (AR); or supplemented with nicotinamide-low (LN, 300 mg/l), medium (MN, 750 mg/l), or high (HN, 1500 mg/l). Liver to body weight ratios were higher in all artificially reared groups (AR, LN, MN, HN) compared to MR pups. The amount of recovered hepatic microsomal protein was lower in all artificially reared groups when compared with MR pups. Uridine diphosphoglucuronyl transferase activity with para-nitrophenol as the substrate (UDPGT-PNP) was greater in all of the artificially reared groups compared to the MR group. UDPGT-PNP activity in the HN group was greater than in the AR, LN, or MN groups. Cytochrome P-450 concentration was highest in the MR group, whereas there were no differences among the artificially reared groups. It was concluded that the artificial rearing process stimulated hepatic UDPGT-PNP activity and depressed cytochrome P-450 concentrations, whereas dietary supplementation with nicotinamide during the preweanling period resulted in a further increase in UDPGT-PNP activity.

Paraquat concentration and renal function in mice fed purified and cereal-based diets.

Paraquat, a broad spectrum herbicide, has differential effects in mice depending upon whether a purified or a cereal-based diet is fed. Male ICR mice were fed either a cereal-based closed-formula diet or a purified diet for 7-14 days. After intraperitoneal injection, radiolabeled paraquat was measured in blood, lung, kidney, liver, heart, and urine over a 48-hr period. Accumulation of organic ions was measured in renal tissue slices at 3 hrs after injection of paraquat. Hematocrit, plasma urea nitrogen, and urine volume were measured from 8 to 72 hr after administration of paraquat. From 3 to 12 hr after injection, concentrations of paraquat in plasma, kidney, and liver were greater in mice fed a purified diet than in mice fed a closed-formula diet. Concentration of paraquat in the lung and urine did not differ between dietary groups over a 48-hr period. Three hours after paraquat intake renal tissue organic ion accumulation was higher in mice fed a purified diet. Within 72 hr after paraquat administration plasma urea nitrogen concentration and hematocrit were greater in mice fed a purified diet. Higher tissue concentrations of paraquat in mice fed a purified diet could explain dietary differences previously observed for LD50 and survival time after paraquat injection. While changes in plasma urea and paraquat concentration in the kidney were observed, the effect of a diet-paraquat interaction on renal function was not conclusive, since there was no difference in excretion of paraquat between the dietary groups.

Lack of effect of a purified diet on carbon tetrachloride or oxygen toxicity.

The study was designed to examine the effect of feeding a purified versus a cereal-based closed formula (control) diet on toxicity to carbon tetrachloride or oxygen. Twenty-eight-day-old male ICR mie were fed a purified or cereal-based closed formula diet for 14 or 84 days. After treatment with carbon tetrachloride or exposure to a 100% oxygen atmosphere, survival time and percentage survival were the same for mice fed either diet. In both dietary groups, carbon tetrachloride injection caused a similar decrease in hepatic nonprotein sulfhydryl compounds and glucose-6-phosphatase activity. It was concluded that, unlike previous findings with the herbicide paraquat, toxicity to carbon tetrachloride or oxygen is not increased by feeding a purified diet compared to a closed formula diet. The results provided further evidence to suggest that a free radical-lipid peroxidation process may not be the primary mechanism of the toxic effects of paraquat.

Alteration of toxicity to paraquat in mice fed a purified or cereal-based diet.

Toxicity to several compounds is affected by dietary changes that by themselves do not result in nutrient deficiency or toxicity. The herbicide paraquat was tested to determine whether feeding a cereal-based closed formula diet or a purified diet would affect the sensitivity of mice to paraquat. After an intraperitoneal injection of paraquat, 28-day-old male ICR mice, which had been fed a purified diet for periods of 3 to 84 days, had shorter survival times and lower 7-day percent survivals than mice fed a cereal-base closed formula diet. The median lethal dose of paraquat was significantly lower in mice fed the purified diet rather than the closed formula diet. Median effective time to death was also significantly shorter for male ICR mice fed the purified diet rather than the closed formula diet. Female ICR mice and male B6C3F1 mice fed the purified diet for 7 days were more susceptible to paraquat toxicity than similar mice fed the closed formula diet. Male C57BL/6J mice were more sensitive to the effects of paraquat regardless of the type of diet. Modifying the content of lipid, vitamin E, or selenium, or adding butylated hydroxytoluene to the purified diet did not prevent a decrease in 7-day percent survival and survival time compared to male ICR mice fed a closed formula diet. Male ICR mice fed the purified diet with egg-white protein had significantly longer survival times compared to mice fed the purified diet with casein. It is concluded that strictly defined diets must be used in the study of paraquat toxicity to control for any paraquat-diet interactions.