Parathyroid adenomas evaluated by Tl-201/Tc-99m pertechnetate subtraction scintigraphy and high-resolution ultrasonography

Thallium-201/technetium-99m pertechnetate subtraction scintigraphy of the parathyroid glands was performed in a prospective study of 33 patients who had undergone bilateral neck exploration for elevated serum calcium and serum parathyroid hormone levels. In 31 cases, the Tl-201/Tc-99m subtraction technique yielded an overall sensitivity of 81%, specificity of 99%, and accuracy of 94% for identifying solitary parathyroid adenomas. Tl-201/Tc-99m subtraction scintigraphy correctly identified 73% of parathyroid adenomas weighing less than 499 mg, 79% of those weighing 500-1,499 mg, and 100% of adenomas weighing more than 1,500 mg. In a subgroup of 24 patients with solitary parathyroid adenomas who underwent both scintigraphy and high-resolution sonography, the sensitivity, specificity, and accuracy of both procedures were similar.     

The Akt of translational control

The oncogene AKT (also called protein kinase B (PKB)) signals to the translational machinery, and activation of protein synthesis by Akt is associated with cancer formation. Akt directly stimulates the activity of translation initiation factors and upregulates ribosome biogenesis. Activation of protein synthesis by Akt is phylogenetically conserved from Drosophila to humans, and is important for regulating cell growth, proliferation and cell survival. Consequently, translation defects due to aberrant Akt activation may be a crucial mechanism leading to tumorigenesis. However, few in vivo studies have established a causative role for aberrant protein synthesis control in cancer. A major challenge in the future will be to identify the specific mRNAs regulated at the level of translation control directly relevant for cellular transformation. In this review, we highlight and discuss the emerging molecular and genetic evidence that support a model by which deregulation of specific or global protein synthesis contributes to cancer.     

Radiofrequency tumor ablation: insight into improved efficacy using computer modeling

OBJECTIVE: To use computer modeling of the Bio-Heat equation to demonstrate factors influencing RF ablation tissue heating. CONCLUSION: Computer modeling demonstrates the importance of energy deposition, tumor and background tissue electrical and thermal conductivity, and perfusion on RF ablation outcomes.     

Evaluating medical student obstetrics and gynecology clerkship performance: which assessment tools are most reliable?

OBJECTIVE: This study was undertaken to investigate medical student performance on an obstetrics and gynecology (Ob-Gyn) core clerkship to determine the most discriminating measures of student performance. STUDY DESIGN: Four-hundred twenty-one clinical clerks were assessed with the use of 46 performance indicators in 4 different categories. Final Scores were weighted: (1) Clinical Performance = 60%, (2) Formal Presentation = 10%, (3) Oral Examination = 10%, and (4) National Board of Medical Examiners (NBME) Subject Test score = 20%. RESULTS: A total of 17,023 scores were examined. Final Scores were normally distributed. Clinical Performance and Formal Presentation scores were highly skewed, explaining 35% and 5% of the Final Score variance, respectively. Oral Examination scores were slightly skewed, explaining 17% of the variance. The NBME Subject Test score was the only normally distributed performance indicator and, despite comprising only 20% of Final Scores, was the most highly correlated ( R = 0.86), explaining 74% of the variance. CONCLUSION: Despite their minor weighting in our grading system, NBME Subject Test scores were very highly correlated with overall clinical clerkship performance. By combining written Subject Test and Oral Examination scores, 91% of the variance in Final Scores can be explained.