Multicenter comparison of different real-time PCR assays for quantitative detection of Epstein-Barr virus.

Quantification of Epstein-Barr virus (EBV) in peripheral blood is important for the diagnosis and management of serious EBV diseases, including posttransplant lymphoproliferative disorder. A variety of PCR-based methods are currently in use; however, there is little information on their comparability. This study assessed the relative performance of different quantitative assays. A multicenter comparative study was performed at eight sites using three panels consisting of serial dilutions of quantified EBV DNA and extracts from a total of 19 whole-blood specimens. Samples were distributed and tested blindly. Instrumentation, probe chemistries, amplification targets, and other test-related aspects varied considerably between laboratories. Each laboratory's calibration curve indicated strong evidence of a consistent log-linear relationship between viral load and cycle threshold, suggesting that intralaboratory tracking of a given patient would yield similar relative quantitative trends among the participating test sites. There was strong concordance among laboratories with respect to qualitative test results; however, marked quantitative discordance was seen. For most samples, the across-laboratory interquartile range of the reported viral load (in copies/microl) was roughly 0.6 log-units, and for one sample the overall range was approximately 4.2 log-units. While intralaboratory tracking of patients may yield similar results, these data indicate a need for caution when attempting to compare clinical results obtained at different institutions and suggest the potential value to be gained by more standardized testing methodology.

Anabolic agents.

This article provides a comprehensive but practical discussion of four anabolic agents used by athletes. Anabolic-androgenic steroids, dehydroepiandrosterone, human growth hormone, and insulin-like growth factor are discussed. A thorough review of available literature on the basic chemistry and physiology, epidemiology, reasons for use, and performance and side effects of each agent are also presented.

The role of the medial prefrontal cortex (cingulate gyrus) in the regulation of hypothalamic-pituitary-adrenal responses to stress.

In the studies reported here we have examined the role of the medial prefrontal cortex (MpFC) in regulating hypothalamic-pituitary-adrenal (HPA) activity under basal and stressful conditions. In preliminary studies we characterized corticosteroid receptor binding in the rat MpFC. The results revealed high-affinity (Kd approximately 1 nM) binding with a moderate capacity (42.9 +/- 3 fmol/mg) for 3H-aldosterone (with a 50-fold excess of cold RU28362; mineralocorticoid receptor) and high-affinity (Kd approximately 0.5-1.0 nM) binding with higher capacity (183.2 +/- 22 fmol/mg) for 3H-RU 28362 (glucocorticoid receptor). Lesions of the MpFC (cingulate gyrus) significantly increased plasma levels of both adrenocorticotropin (ACTH) and corticosterone (CORT) in response to a 20 min restraint stress. The same lesions had no effect on hormone levels following a 2.5 min exposure to ether. Implants of crystalline CORT into the same region of the MpFC produced a significant decrease in plasma levels of both ACTH and CORT with restraint stress, but again, there was no effect with ether stress. Neither MpFC lesions nor CORT implants had any consistent effect on A.M. or P.M. levels of plasma ACTH or CORT. Manipulations of MpFC function were not associated with changes in the clearance rate for CORT or in corticosteroid receptor densities in the pituitary, hypothalamus, hippocampus, or amygdala. Taken together, these findings suggest that MpFC is a target site for the negative-feedback effects of glucocorticoids on stress-induced HPA activity, and that this effect is dependent upon the nature of the stress.

Peripheral benzodiazepine binding sites in Alzheimer's disease frontal and temporal cortex.

Much evidence has accumulated to suggest that the peripheral type benzodiazepine (PBZ) binding site has a predominantly glial localization. Elevated PBZ binding densities have been reported in various models of brain damage, apparently reflecting glial proliferation in response to neurodegeneration. In the present study, PBZ receptor densities were examined in frontal and temporal cortex of Alzheimer's disease (AD) patients using the ligand [3H]PK 11195. There was a highly significant (p less than 0.01) increase in PBZ binding sites in the temporal cortex from AD patients. In the frontal cortex, a moderate increase was observed that approached statistical significance (p = 0.07). Decreased choline acetyltransferase activity was observed in both regions. These findings offer support for the potential use of the PBZ binding site as a marker for gliosis associated with neuronal cell death.

Effect of increasing estradiol levels on platelet peripheral benzodiazepine binding sites in women undergoing human menopausal gonadotropin treatment.

The effect of increasing serum estradiol levels on platelet [3H]PK 11195 binding was investigated to determine the influence of gonadal steroids on platelet peripheral benzodiazepine binding sites. Serum estradiol and platelet [3H]PK 11195 binding were determined in 10 anovulatory, but otherwise healthy women before and after treatment with human menopausal gonadotropin. Despite a 30-fold increase in posttreatment estradiol, the kinetic parameters of platelet [3H]PK 11195 binding (Kd, Bmax) remained essentially unchanged. These data indicate that peripheral benzodiazepine binding sites on platelets are not influenced by elevated concentrations of estradiol. Thus, it is suggested that variations in circulating levels of this female gonadal steroid are likely not responsible for the modifications in platelet peripheral benzodiazepine binding sites seen in association with various disease states.

Health abuse marketing.

The Health Care Industry is being challenged by diverse needs and demands from the population at large. A growing market is the chemically dependent and the variety of situations that each individual and substance brings. As the public awareness and education increases, organizations, hospitals and groups are responding. This paper will discuss the behaviors around cigarettes, food, alcohol, co-dependency and drugs along with programs and approaches established to address these issues.

Clinical experience with steroid-eluting unipolar electrodes.

In continuing search of low chronic threshold leads, a new concept of electrode design which is capable of delivering corticosteroids at the myocardial tissue interface has been made available by Medtronic. Twenty-three patients, 17 females and 6 males, were either implanted with 4003 (n = 21) or 5023 (n = 2) steroid-eluting electrodes in the ventricular chamber. Pacing modes utilized were VVIM (n = 13) or DDD (n = 10). Pulse generators used were Medtronic (7005, 8317, 8329) Pacesetter (285) and Intermedics (283). Thresholds at the time of implantation at 0.50 msec pulse width were 0.40 +/- 0.02 volts at 0.66 +/- 0.05 milliamps. Resistance and R wave measured were 565.43 +/- 22.07 ohms and 9.24 +/- 1.06 mv, respectively. Chronic thresholds were checked on routine follow-up visits by either decreasing pulse width and/or pulse amplitude. Data is being reported between 1 and 88 (23.22 +/- 4.35) weeks. Pulse width threshold at 2.5 volts were 0.10 msec (n = 11) and 0.05 msec or lower (n = 12). At 5.0 volts no loss of capture was seen at 0.05 msec (n = 22) except in one patient at 0.10 msec. Pulse width thresholds in the first 24 weeks were lower than 0.20 msec at 2.5 volts (n = 15) and less than 0.70 msec. at 0.8 volts (n = 6). No loss of sensing was seen by electrocardiographic analysis at the time of threshold checks with the pulse generator at standard setting of the R wave. Thus, in this initial report, the steroid-eluting electrodes have demonstrated very low thresholds both in the early and chronic follow-up phase.(ABSTRACT TRUNCATED AT 250 WORDS)