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The regional distributions of monoamine oxidase (MAO) types A and B have been identified in human brain in vivo with intravenously injected 11C-labeled suicide enzyme inactivators, clorgyline and L-deprenyl, and positron emission tomography. The rapid brain uptake and retention of radioactivity for both 11C tracers indicated irreversible trapping. The anatomical distribution of 11C paralleled the distribution of MAO A and MAO B in human brain in autopsy material. The corpus striatum, thalamus, and brainstem contained high MAO activity. The magnitudes of uptake of both [11C]clorgyline and L-[11C]deprenyl were markedly reduced in one subject treated with the antidepressant MAO inhibitor phenelzine. A comparison of the brain uptake and retention of the 11C-labeled inactive (D-) and active (L-) enantiomers of deprenyl showed rapid clearance of the inactive enantiomer and retention of the active enantiomer within MAO B-rich brain structures, in agreement with the known stereoselectivity of MAO B for L-deprenyl. Prior treatment with unlabeled L-deprenyl prevented retention of L-[11C]deprenyl. Thus, suicide enzyme inactivators labeled with positron emitters can be used to quantitate the distribution and kinetic characteristics of MAO in human brain structures.

The aim of this study was to determine the effects of initial treatment with a GnRH agonist on body composition in asymptomatic men with nonmetastatic prostate cancer. Forty men with locally advanced, node-positive or biochemically recurrent prostate cancer, no radiographic evidence of metastases, and no prior androgen deprivation therapy were treated with leuprolide 3-month depot 22.5 mg im every 12 wk for 48 wk. The main outcome measures were percentage changes in weight, percentage fat body mass, percentage lean body mass, fat distribution, and muscle size after 48 wk. Thirty-two subjects were evaluable. Serum T concentrations decreased by 96.3% plus or minus 0.4% (P < 0.001). Weight increased by 2.4% plus or minus 0.8% (P = 0.005). Percentage fat body mass increased by 9.4% plus or minus 1.7% (P < 0.001), and percentage lean body mass decreased by 2.7% plus or minus 0.5% (P < 0.001). Cross-sectional areas of the abdomen and abdominal sc fat increased by 3.9% plus or minus 1.2% (P = 0.003) and 11.1% plus or minus 3.4% (P = 0.003), respectively. In contrast, the cross-sectional area of intraabdominal fat did not change significantly (P = 0.94). Cross-sectional paraspinal muscle area decreased by 3.2% plus or minus 1.3% (P = 0.02). GnRH agonists increase weight and percentage fat body mass and decrease percentage lean body mass and muscle size in men with nonmetastatic prostate cancer. Increased fatness resulted primarily from accumulation of sc rather than intraabdominal adipose tissue.

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BACKGROUND A new miniature high-resolution pocket-mobile echocardiographic (PME) device has become available to clinicians, but there are no data available comparing this technology with standard transthoracic echo (TTE) examination. OBJECTIVE To assess the potential validity of PME imaging as a quick assessment of cardiovascular disease by direct comparison to standard TTE. DESIGN Ultrasonographers attempted to acquire seven standard echocardiography views with the PME prior to performing comprehensive standard TTEs. In blinded fashion, images from the two modalities were compared by two experienced echocardiographers and two cardiology fellows. PRIMARY FUNDING SOURCE This work was funded in part by Scripps Health and the NIH UL1 RR025774 (Scripps Translational Science Institute, Clinical and Translational Science Award). SETTING Scripps Clinic/Green Hospital PATIENTS 97 consecutive unselected patients MEASUREMENTS Comparisons were made in regards to ejection fraction (EF), segmental wall motion abnormalities (WMA), left ventricular end-diastolic dimension (LVEDD), inferior vena cava (IVC) size, aortic and mitral valve pathology, and pericardial effusion. RESULTS PME images were adequate for interpretation of EF in 95% of the studies, LVEDD 95%, mitral valve 90%, WMA 83%, aortic valve 83%, and IVC 75%. Compared to standard TTE, PME interpretation by attendings and fellows had an accuracy of 97% and 93% for EF, respectively. Likewise, accuracy for WMA was 90% and 87% ; LVEDD 94% and 91%; aortic stenosis 97% and 95%; mitral abnormality 88% and 82%; and IVC size 81% and 74%. LIMITATIONS As this was a validation study of imaging alone, further evaluation with clinician image acquisition is needed. CONCLUSIONS PME images obtained rapidly by skilled ultrasonographers provide excellent visualization in the vast majority of patients and correlate well with standard, comprehensive TTE. Such validation needs to be extended to untrained clinicians in larger and diverse patient populations before broad dissemination of this technology can be recommended.