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Purpose: The detection of recurrent pituitary adenoma by magnetic resonance imaging (MRI) is rendered uncertain by the tissue remodelling that follows surgery or radiotherapy. We aimed to evaluate the contribution of PET with 11C-methionine (MET-PET) in the detection and management of recurrent pituitary adenoma. Methods: Thirty-three patients with pituitary adenoma were evaluated postoperatively by MET-PET, either because of biological evidence of active residual tumour or because of MRI demonstration of non-functional adenoma growth. We studied 24 secreting adenomas and nine nonfunctional adenomas. Results: In 30 patients, MET-PET detected abnormally hypermetabolic tissue. In 14 out of these, MRI did not differentiate between residual tumour and scar formation. In nine of these 14 cases, major therapeutic decisions were undertaken (radiosurgery and surgery). In another group of 16 patients, both MET-PET and MRI detected abnormal tissue. In one case, neither MRI nor MET-PET detected adenomatous tissue. Finally, abnormal tissue was detected in two patients on MRI solely. In these two cases, failure of MET-PET to reveal the adenoma was attributable to concomitant inhibitory therapy. The sensitivity of METPET and MRI varied as a function of the tumour type: all non-functional adenomas were localised by both modalities, while MET-PET detected all adrenocorticotropic hormone-secreting adenomas whereas MRI depicted only one of these eight lesions. Fifteen out of 17 patients treated by radiosurgery showed clinical improvement after treatment. Conclusion: We suggest that MET-PET is a sensitive technique complementary to MRI for the detection of residual or recurrent pituitary adenomas. It should gain a place in the efficient management of these tumours. [ABSTRACT FROM AUTHOR]

Eugenics casts a long shadow over contemporary genetics. Any measure, whether in clinical genetics or biotechnology, which is suspected of eugenic intent is likely to be opposed on that ground. Yet there is little consensus on what this word signifies, and often only a remote connection to the very complex set of social movements which took that name. After a brief historical summary of eugenics, this essay attempts to locate any wrongs inherent in eugenic doctrines. Four candidates are examined and rejected. The moral challenge posed by eugenics for genetics in our own time, I argue, is to achieve social justice. [ABSTRACT FROM AUTHOR]

Background: Serotonin receptors may play an important role in the pathophysiology of affective disorders. We studied type-2 serotonin (5-HT2) receptors in the brain of patients with major depression.Method: Using positron emission tomography (PET) and the selective radioligand [18F]altanserin, we investigated 5-HT2 receptor distribution in eight drug-free unipolar depressed patients and 22 healthy subjects. Data were analysed using Statistical Parametric Mapping 95.Results: In depressed patients, [18F]altanserin uptake was significantly reduced in a region of the right hemisphere including the posterolateral orbitofrontal cortex and the anterior insular cortex. A trend to similar changes was found in the left hemisphere. No correlation was found between the uptake and the Hamilton rating scale score.Conclusions: Pathophysiology of depression may involve changes in 5-HT2 receptor in brain regions selectively implicated in mood regulation. [ABSTRACT FROM AUTHOR]

Considers whether American bioethics needs an American Association of Bioethics. Reports that representatives of a number of organizations active in bioethics met recently at the New York Academy of Medicine to discuss the need. Places of agreement and debate.

Serotonin constricts coronary arteries with endothelial dysfunction, a common abnormality in cardiac transplant recipients. To assess whether endothelial dysfunction is associated with myocardial blood flow (MBF) abnormalities, 24 patients were studied 1 to 12 months after transplantation. Serotonin in increasing doses (1, 10, and 20 micrograms/min for 2.5 min each) was infused into the coronary circulation. Diameters were measured by quantitative angiography. Fourteen patients (group A) had a pronounced artery constriction (diameter reduction > 40%), while in 10 other patients (group B), such a constriction was never reached. No patient had evidence of rejection and all had angiographically normal coronary arteries. MBF was measured at rest and after intravenous dipyridamole with dynamic nitrogen-13 ammonia positron emission tomography (PET). The resting MBF was higher in group A than in group B (94 +/- 12 vs 74 +/- 15 ml/min/100 g of tissue; p < 0.05). During dipyridamole, MBF was not significantly different (191 +/- 53 vs 184 +/- 64 ml/min/100 g; p = NS). Coronary flow reserve (the ratio of perfusion after dipyridamole to perfusion at rest) was significantly lower in group A than in group B (2.08 +/- 0.54 vs 2.66 +/- 0.57; p < 0.05). Thus, coronary hypersensitivity to serotonin in cardiac transplant recipients is associated with elevated resting MBF and reduced coronary flow reserve. Immune mechanisms inducing endothelial injuries and inflammation-related hyperemia may account for these abnormalities. [ABSTRACT FROM AUTHOR]