The effects of caffeine on food and water intake was assessed in rats maintained under several experimental conditions. In Experiment 1, caffeine, 3.125, 6.25, 12.5, 25.0, 50.0 or 100.0 mg/kg was injected into 23 hr food deprived, 23 hr water deprived or ad lib animals. In Experiment 2, animals were adapted to a 21 hr food deprivation schedule and administered the same doses of caffeine as were used in Experiment 1. Results indicate that caffeine both enhances and decreases food and water intake and that the effects observed depend on the experimental circumstances.

Animals↗

PubMed1977

Academic achievement as a function of specific and global measures of self-concept.

This study examined the correlations between academic achievement and factor specific, as well as global, measures of self-concept for 314 fourth and sixth grade boys and girls divided into grade level groups with and without Spanish surnames. The Primary Self-Concept Inventory was used to measure self-concept on six scales: physical size, emotional state, peer acceptance, helpfulness, success, and student-self. A global self-concept score was derived by totaling the scores on the six scales. Achievement was measured as total score on the Comprehensive Tests of Basic Skills. The two specific measures of self-concept that were most reflective of school performance, success and student-self, tended to show low positive correlations with achievement. The remaining specific measures, as well as the global measure, tended to show no relationship to achievement. These results suggest that an area specific model of self-concept is more useful than a global or undifferentiated model. Further, the low correlations between school related self-concept and achievement suggest that, as a group, students frequently have rather inaccurate academic self-concepts.

Achievement↗

PubMedDate not supplied

Validation of left ventricular volume measurements by gated SPECT 99mTc-labeled sestamibi imaging.

BACKGROUND: Previous studies have shown that gated single photon emission computed tomography (SPECT) technetium 99-labeled sestamibi imaging provides accurate and reproducible measurement of left ventricular (LV) ejection fraction (EF), wall motion, and thickening. This study examined the reliability of gated SPECT sestamibi imaging in measuring LV end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV). METHODS AND RESULTS: Gated SPECT measurements were compared with an independent nongeometric method based on thermodilution SV and first-pass radionuclide angiographic EF (using a multicrystal gamma camera). Twenty-four patients aged 58+/-11 years underwent cardiac catheterization and coronary angiography for evaluation of chest pain syndromes. None had primary valvular disease, intracardiac shunts, or atrial fibrillation. RESULTS: The correlation between the two methods were as follows: EDV: r = 0.89, P<.001; ESV: r = .938, P<.001; SV: r = 0.577, P<.001. Bland-Altman plots showed mean differences (+/-standard deviation [SD]) for EDV of -14.3+/-33.3 mL, for ESV of -0.4+/-23.7 mL, and for SV of -13.9+/-15.2 mL. The reproducibility of measuring EDV and ESV by gated SPECT was very high (r = 0.99 each). CONCLUSION: Gated 99mTc-labeled sestamibi SPECT provides reproducible LV volume measurements. With validation of volume measurement, gated SPECT provides comprehensive assessment of regional and global LV function. This information is important in many patient groups such as those with ischemic cardiomyopathy, concomitant coronary and valve disease, and those who have had myocardial infarction. It will also be useful to assess the incremental value of LV volumes in risk assessment.

Cardiac Output↗

PubMedDate not supplied

New payment incentives affect management strategies in Maryland and New Jersey.

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Maryland↗