Learning styles of physiology students interested in the health professions.

Student learning may be classified according to the sensory modalities by which one prefers to take in information. One such classification scheme uses the VARK instrument, which categorizes learning preferences as visual (V), auditory (A), reading-writing (R), or kinesthetic (K). Many students have a single, strong preferences ("unimodal"), whereas others have multiple ("multimodal") learning preferences. Although limited in scope and reliability, knowledge of student learning preferences is important for reasons of pedagogy. Teaching and student learning styles may also affect student academic success in science coursework and fulfillment of student career goals. In our study, we determined the learning preferences of upper-division students in a human physiology course during a 2-yr period at a public undergraduate institution in California. We also sought to determine the association between individual learning styles and stated career intentions. We found that the majority of students interested in the health professions have multimodal learning preferences. Furthermore, a greater percentage of premedical students had multimodal preferences compared with predental and prescientist students. When data were compared by gender, we found that more female than male students had multimodal learning preferences. We also observed some gender differences when separating student groups by career choice. For example, more premedical men had multimodal preferences compared with nonpremedical men. In contrast to men, women showed little differences in their learning style profiles whether premedical or not and also self-predicted their learning preferences more accurately. Thus, career choice may be an important consideration in determining whether or not there are gender differences among students.

Evaluation of lactate and alanine as metabolic biomarkers of prostate cancer using 1H HR-MAS spectroscopy of biopsy tissues.

The goal of this study was to investigate the use of lactate and alanine as metabolic biomarkers of prostate cancer using (1)H high-resolution magic angle spinning (HR-MAS) spectroscopy of snap-frozen transrectal ultrasound (TRUS)-guided prostate biopsy tissues. A long-echo-time rotor-synchronized Carr-Purcell-Meiboom-Gill (CPMG) sequence including an electronic reference to access in vivo concentrations (ERETIC) standard was used to determine the concentrations of lactate and alanine in 82 benign and 16 malignant biopsies (mean 26.5% +/- 17.2% of core). Low concentrations of lactate (0.61 +/- 0.28 mmol/kg) and alanine (0.14 +/- 0.06 mmol/kg) were observed in benign prostate biopsies, and there was no significant difference between benign predominantly glandular (N = 54) and stromal (N = 28) biopsies between patients with (N = 38) and without (N = 44) a positive clinical biopsy. In biopsies containing prostate cancer there was a highly significant (P < 0.0001) increase in lactate (1.59 +/- 0.61 mmol/kg) and alanine (0.26 +/- 0.07 mmol/kg), and minimal overlap with lactate concentrations in benign biopsies. This study demonstrates for the first time very low concentrations of lactate and alanine in benign prostate biopsy tissues. The significant increase in the concentration of both lactate and alanine in biopsy tissue containing as little as 5% cancer could be exploited in hyperpolarized (13)C spectroscopic imaging (SI) studies of prostate cancer patients.

Feasibility of using hyperpolarized [1-13C]lactate as a substrate for in vivo metabolic 13C MRSI studies.

The development of dynamic nuclear polarization in solution has enabled in vivo 13C MR studies at high signal-to-noise ratio following injection of prepolarized 13C substrates. While prior studies have demonstrated the ability to observe metabolism following injection of hyperpolarized 13C pyruvate, the goal of this study was to develop and test a new hyperpolarized agent for investigating in vivo metabolism, [1-13C]lactate. A preparation for prepolarized 13C lactate and the requisite dissolution media were developed to investigate the feasibility for in vivo 13C MRS/MRSI studies following injection of this hyperpolarized agent. This study demonstrated, for the first time, not only the ability to detect hyperpolarized [1-13C]lactate in vivo but also the metabolic products 13C pyruvate, 13C alanine and 13C bicarbonate following injection in normal rats. The use of 13C lactate as a substrate provided the opportunity to study the conversion of lactate to pyruvate in vivo and to detect the secondary conversions to alanine and bicarbonate through pyruvate. This study also demonstrated the potential value of this hyperpolarized agent to investigate in vivo lactate uptake and metabolism in preclinical animal models.