Summary of the Report of the Ad Hoc Task Force on Psychopharmacology of the American Psychological Association

The American Psychological Association Board of Directors established an ad hoc task force on psychopharmacology to explore the desirability and feasibility of psychopharmacology prescription privileges for psychologists. In this context, the Task Force's charges were to determine the competence criteria necessary for training psychologists to provide service to patients receiving medications and to develop and evaluate the necessary curricular models. This article summarizes the Task Force's major recommendations and provides specific information regarding its training recommendations . It is hoped that this article will encourage broad discussion of psychology's most appropriate integration of psychopharmacology knowledge and its applications into its training programs and professional activities.

Collagen response and glycoprotein VI function decline progressively as canine platelets age in vivo

Clinical and experimental observations suggest that platelet function deteriorates quickly with cell age. However, efforts to define age-dependent alterations have detected only modest biochemical changes occurring late in the cell life span. In this report, we demonstrate two significant alterations of the collagen response occurring during in vivo aging of canine platelets: a progressive increase in the EC50 for collagen types I, III and V and the emergence of a population of aged platelets which are refractory to collagen. Experiments with convulxin, a specific agonist for the collagen receptor glycoprotein VI (GPVI), also demonstrate an age-dependent decline in activation and the appearance of a non-reactive, aged population as observed with native collagens. Our studies indicate that canine platelets have two distinct binding levels for FITC-labeled convulxin and that the higher binding level disappears upon cell aging. During these studies one dog (#428) was identified whose platelets not only failed to demonstrate an age-dependent decrease in convulxin reactivity but also maintained a high convulxin-binding ability throughout their otherwise normal life span. Transfusion of biotinylated platelets from control dogs into dog #428 showed that the expected changes in collagen response and GPVI function did not occur in the transfused platelets. These observations demonstrate that the canine platelet response towards collagen is strongly dependent upon cell-age and suggest that this functional decline is at least partly due to an extrinsic-mediated alteration, possibly proteolytic, of GPVI.

Stimulated platelets use serotonin to enhance their retention of procoagulant proteins on the cell surface

Activated platelets bind numerous adhesive and procoagulant proteins by receptor-mediated processes. Although there is little evidence to suggest that these processes are heterogeneous in platelets, we previously found that platelets co-stimulated with collagen and thrombin express functional alpha-granule factor V only on a subpopulation of cells. Here we show that these cells, referred to as 'COAT-platelets', bind additional alpha-granule proteins, including fibrinogen, von Willebrand factor, thrombospondin, fibronectin and alpha2-antiplasmin. These proteins are all transglutaminase substrates, and inhibitors of transglutaminase prevent the production of COAT-platelets. A synthetic transglutaminase substrate (CP15) also binds to COAT-platelets, and analysis by high performance liquid chromatography/mass spectrometry shows that a product is formed with a relative molecular mass (Mr) equal to CP15 plus 176. Serotonin, an abundant component of platelet-dense granules, has an Mr of 176, and fibrinogen isolated from COAT-platelets contains covalently linked serotonin. Synthetic bovine serum albumin-(serotonin)6 binds selectively to COAT-platelets and also inhibits the retention of procoagulant proteins on COAT-platelets. These data indicate that COAT-platelets use serotonin conjugation to augment the retention of procoagulant proteins on their cell surface through an as yet unidentified serotonin receptor.

Surface expression and functional characterization of alpha-granule factor V in human platelets: effects of ionophore A23187, thrombin, collagen, and convulxin

Factor V (FV) present in platelet alpha-granules has a significant but incompletely understood role in hemostasis. This report demonstrates that a fraction of platelets express very high levels of surface-bound, alpha-granule FV on simultaneous activation with 2 agonists, thrombin and convulxin, an activator of the collagen receptor glycoprotein VI. This subpopulation of activated platelets represents 30.7% +/- 4.7% of the total population and is referred to as convulxin and thrombin-induced-FV (COAT-FV) platelets. COAT-FV platelets are also observed on activation with thrombin plus collagen types I, V, or VI, but not with type III. No single agonist examined was able to produce COAT-FV platelets, although ionophore A23187 in conjunction with either thrombin or convulxin did generate this population. COAT-FV platelets bound annexin-V, indicating exposure of aminophospholipids and were enriched in young platelets as identified by the binding of thiazole orange. The functional significance of COAT-FV platelets was investigated by demonstrating that factor Xa preferentially bound to COAT-FV platelets, that COAT-FV platelets had more FV activity than either thrombin or A23187-activated platelets, and that COAT-FV platelets were capable of generating more prothrombinase activity than any other physiologic agonist examined. Microparticle production by dual stimulation with thrombin and convulxin was less than that observed with A23187, indicating that microparticles were not responsible for all the activities observed. These data demonstrate a new procoagulant component produced from dual stimulation of platelets with thrombin and collagen. COAT-FV platelets may explain the unique role of alpha-granule FV and the hemostatic effectiveness of young platelets. (Blood. 2000;95:1694-1702)

Effect of echo time pair selection on quantitative analysis for adrenal tumor characterization with in-phase and opposed-phase MR imaging: initial experience

PURPOSE: To determine the effect of two pairs of echo times (TEs) for in-phase (IP) and opposed-phase (OP) 3.0-T magnetic resonance (MR) imaging on (a) quantitative analysis prospectively in a phantom study and (b) diagnostic accuracy retrospectively in a clinical study of adrenal tumors, with use of various reference standards in the clinical study. MATERIALS AND METHODS: A fat-saline phantom was used to perform IP and OP 3.0-T MR imaging for various fat fractions. The institutional review board approved this HIPAA-compliant study, with waiver of informed consent. Single-breath-hold IP and OP 3.0-T MR images in 21 patients (14 women, seven men; mean age, 63 years) with 23 adrenal tumors (16 adenomas, six metastases, one adrenocortical carcinoma) were reviewed. The MR protocol involved two acquisition schemes: In scheme A, the first OP echo (approximately 1.5-msec TE) and the second IP echo (approximately 4.9-msec TE) were acquired. In scheme B, the first IP echo (approximately 2.4-msec TE) and the third OP echo (approximately 5.8-msec TE) were acquired. Quantitative analysis was performed, and analysis of variance was used to test for differences between adenomas and nonadenomas. RESULTS: In the phantom study, scheme B did not enable discrimination among voxels that had small amounts of fat. In the clinical study, no overlap in signal intensity (SI) index values between adenomas and nonadenomas was seen (P < .05) with scheme A. However, with scheme B, no overlap in the adrenal gland SI-to-liver SI ratio between adenomas and nonadenomas was seen (P < .05). With scheme B, no overlap in adrenal gland SI index-to-liver SI index ratio between adenomas and nonadenomas was seen (P < .05). CONCLUSION: This initial experience indicates SI index is the most reliable parameter for characterization of adrenal tumors with 3.0-T MR imaging when obtaining OP echo before IP echo. When acquiring IP echo before OP echo, however, nonadenomas can be mistaken as adenomas with use of the SI index value.