Diagnostic Value of the Preoperative Sestamibi Scan in Intraoperative Localization of Parathyroid Adenomas: A Case Study

A retrospective chart review of 43 patients who underwent technetium 99m (Tc-99m) sestamibi scans from June 1995 to January 1997 was performed. Only those who underwent subsequent parathyroid exploration with excision were included in the study. Twenty subjects (13 women and seven men) were included in the study. Ages ranged from 21 to 84 years (mean, 58 years). All patients had laboratory values and clinical findings consistent with primary hyperparathyroidism. Two patients had preoperative magnetic resonance imaging (MRI) scans (one patient with recurrent disease), and one had a preoperative computed tomography (CT) scan. The remaining patients had the sestamibi scan as the only preoperative localization study. There were 18 pathologic diagnoses of parathyroid adenoma and two of parathyroid hyperplasia. Sestamibi failed to correctly identify the location of the parathyroid lesion in two cases. In 18 cases the preoperative sestamibi scan correctly localized the lesion, a predictive value of 90%. We conclude that the Tc-99m sestamibi scan is an accurate preoperative tool that can be used as a single modality to localize parathyroid adenomas.     

Assessing professional behavior: yesterday, today, and tomorrow.

PURPOSE: The author interprets the state of the art of assessing professional behavior. She defines the concept of professionalism, reviews the psychometric properties of key approaches to assessing professionalism, conveys major findings that these approaches produced, and discusses recommendations to improve the assessment of professionalism. METHOD: The author reviewed professionalism literature from the last 30 years that had been identified through database searches; included in conference proceedings, bibliographies, and reference lists; and suggested by experts. The cited literature largely came from peer-reviewed journals, represented themes or novel approaches, reported qualitative or quantitative data about measurement instruments, or described pragmatic or theoretical approaches to assessing professionalism. RESULTS: A circumscribed concept of professionalism is available to serve as a foundation for next steps in assessing professional behavior. The current array of assessment tools is rich. However, their measurement properties should be strengthened. Accordingly, future research should explore rigorous qualitative techniques; refine quantitative assessments of competence, for example, through OSCEs; and evaluate separate elements of professionalism. It should test the hypothesis that assessment tools will be better if they define professionalism as behaviors expressive of value conflicts, investigate the resolution of these conflicts, and recognize the contextual nature of professional behaviors. Whether measurement tools should be tailored to the stage of a medical career and how the environment can support or sabotage the assessment of professional behavior are central issues. FINAL THOUGHT: Without solid assessment tools, questions about the efficacy of approaches to educating learners about professional behavior will not be effectively answered.     

Direct effect of acute metabolic and respiratory acidosis on parathyroid hormone secretion in the dog.

Because both metabolic (Met Acid) and respiratory acidosis (Resp Acid) have diverse effects on mineral metabolism, it has been difficult to establish whether acidosis directly affects parathyroid hormone (PTH) secretion. Our goal was to determine whether acute Met Acid and Resp Acid directly affected PTH secretion. Three groups of dogs were studied: control, acute Met Acid induced by HCl infusion, and acute Resp Acid induced by hypoventilation. EDTA was infused to prevent acidosis-induced increases in ionized calcium, but more EDTA was needed in Met Acid than in Resp Acid. The PTH response to EDTA-induced hypocalcemia was evaluated also. Magnesium needed to be infused in groups receiving EDTA to prevent hypomagnesemia. The half-life of intact PTH (iPTH) was determined during hypocalcemia when PTH was measured after parathyroidectomy. During normocalcemia, PTH values were greater (p < 0.05) in Met Acid (92 +/- 19 pg/ml) and Resp Acid (77 +/- 22 pg/ml) than in controls (27 +/- 5 pg/ml); the respective pH values were 7.23 +/- 0.01, 7.24 +/- 0.01, and 7.39 +/- 0.02. The maximal PTH response to hypocalcemia was greater (p < 0.05) in Met Acid (443 +/- 54 pg/ml) than in Resp Acid (267 +/- 37 pg/ml) and controls (262 +/- 48 pg/ml). The half-life of PTH was greater (p < 0.05) in Met Acid than in controls, but the PTH secretion rate also was greater (p < 0.05) in Met Acid than in the other two groups. In conclusion, (1) both acute Met Acid and Resp Acid increase PTH secretion when the ionized calcium concentration is normal; (2) acute Met Acid may increase the bone efflux of calcium more than Resp Acid; (3) acute Met Acid acts as a secretogogue for PTH secretion because it enhances the maximal PTH response to hypocalcemia.     

Long-term results of pectoralis major muscle transposition for infected sternotomy wounds.

During an 11.5-year period, 100 consecutive patients (79 male, 21 female) underwent repair of an infected sternotomy wound. Sixty-five patients had failed attempts at wound closure by other physicians. Median age was 61.5 years (range, 5 to 85 years). Reconstruction included muscle in 79 patients, omentum in 4, and both in 15. A total of 175 muscles were transposed, including 169 pectoralis major, 3 rectus abdominis, 2 external oblique, and 1 latissimus dorsi. Median number of operations was four (range, 1 to 11). Mechanical ventilation was required in 30 patients. Two perioperative deaths occurred, one related to sepsis. Median follow-up was 4.2 years (range, 1.3 to 13.5 years). Twenty-six patients had recurrent infection. Median time from our closure to recurrence was 5.5 months (range, 0.3 to 27.6 months). Cause of recurrence was inadequate removal of cartilage in 16 patients, bone in 6, and retained foreign body in 4. Eighteen patients had the wound reopened with further resection; 10 had another muscle or omentum transposition. There were 30 late deaths, only one related to recurrent infection. At the time of death or last follow-up, 92 patients had a healed chest wall. Transposition of the pectoralis major muscle remains an excellent method of management for infected sternotomy wounds. Failure is directly related to persistent infection of cartilage, bone, or retained foreign bodies.     

Ischemia independent lesion evolution during focal stroke in rats

Lesion evolution during focal cerebral ischemia may depend on flow restrictions or on accumulation of toxic mediators within the infarct and expansion of these factors to the periinfarct region. So far, the precise contribution of flow dependent versus spreading-mediated impairment of viable periinfarct tissue has not been determined. Therefore, we measured lesion expansion, flow restrictions and glutamate distribution on serial brain sections at different time points after experimental focal ischemia.Permanent focal ischemia was induced by occlusion of the right middle cerebral artery in male rats and the flow reduction was subsequently measured at 1, 12 and 24 h using iodo[¹⁴C]antipyrine autoradiography. Additionally, the necrotic volume was determined on serial brain sections and the glutamate content was measured in tissue samples from adjacent microdissections.Twelve hours after focal ischemia no noteworthy viable areas with blood flow restrictions of 20-40 ml 100 g^− 1 min^− 1 existed but at 24 h the necrotic tissue exceeded the hemodynamically compromised region by 40 ± 21 mm³ (24%). Furthermore, at 12 and 24 h the glutamate content was elevated in areas surrounding the infarct.Relevant flow restrictions are detectable only during early stages of infarct maturation, whereas the propagation of secondary factors may be the predominant mechanism for delayed infarct evolution.     

Quantitative assessment of ALZ-50 immunoreactivity in Alzheimer's disease.

A quantitative assay for ALZ-50 immunoreactivity was evaluated in samples of superior temporal gyrus taken at autopsy from 13 Alzheimer patients and 11 controls. The assayable immunoreactivity appears to be stable for at least 24 hours postmortem but was lost with formalin fixation. The mean value of the Alzheimer patients was tenfold higher than that of the controls (P less than .002). The values of four Alzheimer samples overlapped with the low levels seen in controls, but no controls had elevated levels. In this sample population, therefore, the assay had a sensitivity of 69% and specificity of 100%.