Tetrahydronorharmane (Tetrahydro-β-carboline), a physiologically occurring compound of indole metabolism

Summary In the present paper a sensitive method is described to measure tetrahydronorharmane (THN) in the urine of man and rats as well as in the forebrain of rats. The compound is extracted into diethyl ether, separated by thin layer chromatography (TLC), acetylated with radiolabelled acetic anhydride and further isolated by two-dimensional TLC development. The existence of THN in urine of man was proven by using chromatography with different solvent systems, cocristallisation, isotope dilution technique as well as mass-spectrometry. The amount of THN in the urine varied over a wide range.With the same method it was demonstrated that THN occurs also in the forebrain of rats. The concentration increases after loading with tryptamine.The findings are discussed in view of the hypothesis that THN acts as a compound modulating neuronal mechanism.     

Pattern discrimination with flickering stimuli

The spatial contrast at which Observers are able to discriminate between horizontal and vertical gratings in a 2AFC task shows the same dependence on spatial and temporal frequency as does 2AFC detection. We conclude that mechanisms carrying information about spatial contrast have their sensitivity to low spatial frequency sinusoidal gratings improved by flicker and that such mechanisms are likely to mediate the detection of low spatial-frequency gratings both at low and at high temporal frequencies.     

Multivariate Analysis of Risk Factors for Postoperative Complications in Benign Goiter Surgery: Prospective Multicenter Study in Germany

Risk factors for postoperative complications of benign goiter surgery have not been investigated systematically. To this end, a prospective multicenter study (January 1 through December 31, 1998) was conducted involving 7266 patients with surgery for benign goiter from 45 East German hospitals. High-volume providers (>150 operations per year) performed 69% (5042/7266), intermediate-volume providers 27% (50–150), and low-volume providers 4% (258/7266) of operations. Among the hospital groups, the pattern of thyroid disease did not vary significantly, but there was a trend that small-volume providers tended to perform more operations for uninodular goiter and high-volume providers treated more patients with Graves' disease and recurrent goiter. Extent of resection (p < 0.0001) and remnant size (multinodular goiter and recurrent goiter, p < 0.001), differed significantly, with total thyroidectomy being performed more often in hospitals with more than 150 operations compared to hospitals with an operative volume of less than 150 procedures per year. Despite the larger extent of resection and smaller remnant size, rates of recurrent laryngeal nerve (RLN) palsy or hypoparathyroidism were not increased. When the logistic regression analyses were fitted to evaluate the impact of risk factors on transient and permanent RLN palsy and hypoparathyroidism, larger extent of resection [relative risk (RR) 1.5–2.1] and recurrent goiter (RR 1.8–3.4) consistently evolved as independent risk factors. With hypoparathyroidism, additional significant factors included patient gender (RR 2.1–2.4), hospital operative volume (RR 0.8–1.5), and Graves' disease (RR 2.8). Unlike parathyroid gland identification during hypoparathyroidism, RLN identification (RR 1.6) significantly (p= 0.01) reduced permanent RLN palsy rates. The multivariate analyses clearly confirmed the pivotal role of routine RLN identification, independent of the extent of the thyroid resection. These findings might help hospitals with lower operative volumes to identify patients at increased risk whom they might consider for specialist care.     

Patterns of treatment of patients with prostate cancer initially managed with surveillance: results from The CaPSURE database. Cancer of the Prostate Strategic Urological Research Endeavor

PURPOSE: We determined the demographic and clinical profile of men who elect surveillance as the initial management of prostate cancer as well as the incidence and predictors of secondary treatment of these patients. MATERIALS AND METHODS: The Cancer of the Prostate Strategic Urological Research Endeavor (CaPSURE) is a national disease registry of patients with various stages and treatments of prostate cancer. Using this database of 4,458 men we identified 329 (8.2%) who elected surveillance as the initial management of prostate cancer. Patients choosing watchful waiting were compared to other CaPSURE participants using the chi-square test. The likelihood of treatment initiation in the watchful waiting group was calculated using the Kaplan-Meier method. After adjusting for patient age, race, prostate specific antigen (PSA) at diagnosis, clinical T stage and total Gleason score the Cox proportional hazards regression model was used to determine significant predictors of treatment initiation. RESULTS: Compared with others in the database, patients on watchful waiting were more likely to be 75 years old or older (51% versus 16%, p <0.001), white (93% versus 85%, p <0.001), and have lower serum PSA (p <0.001), organ confined disease (97% versus 88%, p <0.001) and a total Gleason score of 7 or less (97% versus 88%, p <0.001). In the watchful waiting group there was a 52% likelihood of treatment initiation within 5 years of the diagnosis. Significant predictors of secondary treatment were age younger than 65 years and elevated serum PSA at diagnosis. Neither race, extraprostatic stage cT3 disease nor higher total Gleason score was a significant predictor of treatment. CONCLUSIONS: Men who elect initial watchful waiting for prostate cancer tend to be older, have lower serum PSA and more favorable disease characteristics than those who seek treatment. PSA at diagnosis is the dominant factor for predicting secondary treatment.     

Increased fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) uptake in childhood CNS tumors is correlated with malignancy grade: a study with FDG positron emission tomography/magnetic resonance imaging coregistration and image fusion.

PURPOSE Positron emission tomography (PET) has been used in grading of CNS tumors in adults, whereas studies of children have been limited. PATIENTS AND METHODS Nineteen boys and 19 girls (median age, 8 years) with primary CNS tumors were studied prospectively by fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) PET with (n = 16) or without (n = 22) H(2)(15)O-PET before therapy. Image processing included coregistration to magnetic resonance imaging (MRI) in all patients. The FDG uptake in tumors was semiquantitatively calculated by a region-of-interest-based tumor hotspot/brain index. Eight tumors without histologic confirmation were classified as WHO grade 1 based on location, MRI, and clinical course (22 to 42 months). Results Four grade 4 tumors had a mean index of 4.27 +/- 0.5, four grade 3 tumors had a mean index of 2.47 +/- 1.07, 10 grade 2 tumors had a mean index of 1.34 +/- 0.73, and eight of 12 grade 1 tumors had a mean index of -0.31 +/- 0.59. Eight patients with no histologic confirmation had a mean index of 1.04. For these 34 tumors, FDG uptake was positively correlated with malignancy grading (n = 34; r = 0.72; P < .01), as for the 26 histologically classified tumors (n = 26; r = 0.89; P < .01). The choroid plexus papilloma (n = 1) and the pilocytic astrocytomas (n = 3) had a mean index of 3.26 (n = 38; r = 0.57; P < .01). H(2)(15)O-uptake showed no correlation with malignancy. Digitally performed PET/MRI coregistration increased information on tumor characterization in 90% of cases. CONCLUSION FDG PET of the brain with MRI coregistration can be used to obtain a more specific diagnosis with respect to malignancy grading. Improved PET/MRI imaging of the benign hypermetabolic tumors is needed to optimize clinical use.     

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