Treatment Of Healthy Volunteers Research Articles

Alterations in Skeletal Muscle Insulin Signaling DNA Methylation: A Pilot Randomized Controlled Trial of Olanzapine in Healthy Volunteers.

Antipsychotics are associated with severe metabolic side effects including insulin resistance; however, the mechanisms underlying this side effect are not fully understood. The skeletal muscle plays a critical role in insulin-stimulated glucose uptake, and changes in skeletal muscle DNA methylation by antipsychotics may play a role in the development of insulin resistance. A double-blind, placebo-controlled trial of olanzapine was performed in healthy volunteers. Twelve healthy volunteers were randomized to receive 10 mg/day of olanzapine for 7 days. Participants underwent skeletal muscle biopsies to analyze DNA methylation changes using a candidate gene approach for the insulin signaling pathway. Ninety-seven methylation sites were statistically significant (false discovery rate < 0.05 and beta difference between the groups of ≥10%). Fifty-five sites had increased methylation in the skeletal muscle of olanzapine-treated participants while 42 were decreased. The largest methylation change occurred at a site in the Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-Alpha (PPARGC1A) gene, which had 52% lower methylation in the olanzapine group. Antipsychotic treatment in healthy volunteers causes significant changes in skeletal muscle DNA methylation in the insulin signaling pathway. Future work will need to expand on these findings with expression analyses.

St. John's wort extract with a high hyperforin content does not induce P-glycoprotein activity at the human blood-brain barrier.

St. John's wort (SJW) extract, a herbal medicine with antidepressant effects, is a potent inducer of intestinal and/or hepatic cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp), which can cause clinically relevant drug interactions. It is currently not known whether SJW can also induce P-gp activity at the human blood-brain barrier (BBB), which may potentially lead to decreased brain exposure and efficacy of certain central nervous system (CNS)-targeted P-gp substrate drugs. In this study, we used a combination of positron emission tomography (PET) imaging and cocktail phenotyping to gain a comprehensive picture on the effect of SJW on central and peripheral P-gp and CYP activities. Before and after treatment of healthy volunteers (n = 10) with SJW extract with a high hyperforin content (3-6%) for 12-19 days (1800 mg/day), the activity of P-gp at the BBB was assessed by means of PET imaging with the P-gp substrate [11C]metoclopramide and the activity of peripheral P-gp and CYPs was assessed by administering a low-dose phenotyping cocktail (caffeine, omeprazole, dextromethorphan, and midazolam or fexofenadine). SJW significantly increased peripheral P-gp, CYP3A, and CYP2C19 activity. Conversely, no significant changes in the peripheral metabolism, brain distribution, and P-gp-mediated efflux of [11C]metoclopramide across the BBB were observed following the treatment with SJW extract. Our data suggest that SJW does not lead to significant P-gp induction at the human BBB despite its ability to induce peripheral P-gp and CYPs. Simultaneous intake of SJW with CNS-targeted P-gp substrate drugs is not expected to lead to P-gp-mediated drug interactions at the BBB.

A phase 1 study of AL002 in healthy volunteers

AbstractBackgroundTriggering receptor expressed on myeloid cells ‐2 (TREM2) is a prominent Alzheimer’s disease (AD) risk gene that is expressed by microglia in the brain; reduced function of TREM2 is associated with a 3‐fold increase in AD risk. AL002 is a humanized monoclonal IgG1 antibody. The proposed mechanism of action is that it binds to TREM2 and activates the TREM2 signaling pathway to increase the ability of microglia to clear pathology and protect neurons with the goal of treating patients suffering from AD. INVOKE was a first‐in‐human Phase 1 study designed to investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of intravenously administered AL002 in healthy volunteers (HV).MethodINVOKE was a randomized, placebo‐controlled, double‐blind investigation of AL002 in healthy volunteers (HV). The SAD portion of the study, which included a total of 64 HV receiving a single dose of 0.003 to 60 mg/kg AL002 or matching placebo is complete. Blood and CSF biomarkers were measured before dosing and at multiple timepoints after dosing.ResultIn the SAD portion of the INVOKE study, AL002 was generally well tolerated in HV. AL002 decreased sTREM2 in cerebral spinal fluid (CSF), in a dose‐dependent manner, demonstrating proof of target engagement in the brain. Microglia biomarkers of TREM2 activation, such as CSF1R, SPP1 and IL1RN, were identified with in vitro and in vivo non‐clinical experiments. Consistent with these findings, treatment of HV with AL002 caused an increase in CSF levels of CSF1R, SPP1 and IL1RN in a dose‐dependent manner, suggesting proof of microglia activity through the TREM2 pathway.ConclusionAL002 treatment resulted in TREM2 target engagement and proof of activity in the CSF of HVs. These results have supported progressing AL002 to an ongoing Phase 2 study (INVOKE‐2) to investigate its effects on cognitive decline and neurodegeneration in subjects with early AD.

An Experimental Medicine Investigation of the Effects of Subacute Pramipexole Treatment on Emotional Information Processing in Healthy Volunteers.

Treatment with the dopamine D2/D3 receptor agonist pramipexole has demonstrated promising clinical effects in patients with depression. However, the mechanisms through which pramipexole might alleviate depressive symptoms are currently not well understood. Conventional antidepressant drugs are thought to work by biasing the processing of emotional information in favour of positive relative to negative appraisal. In this study, we used an established experimental medicine assay to explore whether pramipexole treatment might have a similar effect. Employing a double-blind, parallel-group design, 40 healthy volunteers (aged 18 to 43 years, 50% female) were randomly allocated to 12 to 15 days of treatment with either pramipexole (at a peak daily dose of 1.0 mg pramipexole salt) or placebo. After treatment was established, emotional information processing was assessed on the neural level by measuring amygdala activity in response to positive and negative facial emotional expressions, using functional magnetic resonance imaging (MRI). In addition, behavioural measures of emotional information processing were collected at baseline and on drug, using an established computerized task battery, tapping into different cognitive domains. As predicted, pramipexole-treated participants, compared to those receiving placebo, showed decreased neural activity in response to negative (fearful) vs. positive (happy) facial expressions in bilateral amygdala. Contrary to our predictions, however, pramipexole treatment had no significant antidepressant-like effect on behavioural measures of emotional processing. This study provides the first experimental evidence that subacute pramipexole treatment in healthy volunteers modifies neural responses to emotional information in a manner that resembles the effects of conventional antidepressant drugs.

ZFP91 Regulates Multiple Myeloma Cell Proliferation through IL-1β Mediated IL-6 Secretion in the Tumor Microenvironment

Multiple myeloma is a malignancy of terminally differentiated plasma cells that are primarily resident in the bone marrow. Despite novel therapies, myeloma remains a fatal disease. Through interactions with immune cells in the bone marrow microenvironment, myeloma cells have been shown to facilitate their own proliferation and drug resistance. Therefore, targeting the immune support cells in the myeloma bone marrow microenvironment could add further value to existing treatment regimens. ZFP91, a C2H2-type zinc-finger protein, is a substrate of IMID drugs (An et al, Nat. Commun. 2017). The downstream target of ZFP91 in myeloma has been elusive so far. Our myeloma-specific ZFP91 interactome data and recent publications indicate an immune related function for ZFP91. A recent study also indicated that treatment of healthy volunteers with iberdomide, impaired the ability of monocytes to secrete IL-1β in response to LPS (Schafer PH, et al. Ann Rheum Dis 2018). To further investigate this, we generated CRISPR knockouts of IKZF1, IKZF3 and ZFP91, three major substrates of lenalidomide and iberdomide, in THP-1 monocytic cells. Upon LPS induction, loss of ZFP91 impaired the ability of THP-1 monocytic cells to secrete IL-1β (WT 70 pg/ml of IL-1β vs ZFP91-/- 4.5 pg/ml of IL-1β). Loss of IKZF1/3, the other two substrates of lenalidomide and iberdomide did not impair IL-1β secretion. IL-1β is a known activator of IL-6, a critical cytokine for myeloma cell proliferation. As a next step, we created a co-culture model to mimic a minimal myeloma tumor microenvironment with ANBL-6 (IL-6 dependent) myeloma cell line and primary bone marrow stromal cells in the presence of pre-conditioned media from LPS stimulated THP-1 monocytes. Preconditioned media from ZFP91-/- monocytes impaired proliferation of myeloma cells in the co-culture model due to lack of IL-1β, the inducer of IL-6 from the stromal cells. Mechanistically, loss of ZFP91 impairs the TLR4 signaling pathway. Thus, targeting ZFP91 impairs proliferation of myeloma cells within the bone marrow microenvironment by acting in trans from monocytes. Our findings for the first time identify a tumor cell proliferative role for ZFP91 in the myeloma tumor microenvironment. In addition, it establishes ZFP91 as an immune substrate of lenalidomide and iberdomide and could be a key player that mediates the immune functions observed. Disclosures Jeyaraju: Celgene Corporation: Employment, Equity Ownership. Kumari:Celgene Corporation: Employment. Amatangelo:Celgene Corporation: Employment, Equity Ownership. Bjorklund:Celgene Corporation: Employment, Equity Ownership. Hsu:Celgene Corporation: Employment. Thakurta:Celgene: Employment, Equity Ownership.

Low molecular weight heparins prevent the induction of autophagy of activated neutrophils and the formation of neutrophil extracellular traps

The protection exerted by neutrophils against invading microbes is partially mediated via the generation of neutrophil extracellular traps (NETs). In sterile conditions NETs are damaging species, enriched in autoantigens and endowed with the ability to damage the vessel wall and bystander tissues, to promote thrombogenesis, and to impair wound healing. To identify and reposition agents that can be used to modulate the formation of NETs is a priority in the research agenda. Low molecular weight heparins (LMWH) are currently used, mostly on an empirical basis, in conditions in which NETs play a critical role, such as pregnancy complications associated to autoimmune disease. Here we report that LMWHs induce a profound change in the ability of human neutrophils to generate NETs and to mobilize the content of the primary granules in response to unrelated inflammatory stimuli, such as IL-8, PMA and HMGB1. Autophagy consistently accompanies NET generation in our system and autophagy inhibitors, 3-MA and wortmannin, prevent NET generation. Pretreatment with LMWH in vitro critically jeopardizes neutrophil ability to activate autophagy, a mechanism that might contribute to neutrophil unresponsiveness. Finally, we verified that treatment of healthy volunteers with a single prophylactic dose of parnaparin abrogated the ability of neutrophils to activate autophagy and to generate NETs. Together, these results support the contention that neutrophils, and NET generation in particular, might represent a preferential target of the anti-inflammatory action of LMWH.

Inhaled loxapine and intramuscular lorazepam in healthy volunteers: a randomized placebo-controlled drug-drug interaction study.

Pharmacodynamic effects and safety of single‐dose inhaled loxapine administered via the Staccato® system and intramuscular (IM) lorazepam in combination versus each agent alone were compared in a randomized, double‐blind, crossover study in healthy volunteers. Subjects received: inhaled loxapine 10 mg + IM lorazepam 1 mg; inhaled loxapine 10 mg + IM placebo; IM lorazepam 1 mg + Staccato placebo in random order, each separated by a 3‐day washout. Primary endpoints were maximum effect (minimum value) and area under the curve (AUC) from baseline to 2 h post treatment for respirations/min and pulse oximetry. Least‐squares means (90% confidence interval [CI]) for concomitant treatment versus each agent alone were derived and equivalence (no difference) confirmed if the 90% CI was within 0.8–1.25. Blood pressure (BP), heart rate (HR), sedation (100‐mm visual analog scale), and adverse events (AEs) were recorded. All 18 subjects (mean age, 20.4 years; 61% male) completed the study. There was no difference between inhaled loxapine + IM lorazepam and either agent alone on respiration or pulse oximetery during the 12‐h postdose period, confirmed by 90% CIs for AUC and C min ratios. BP and HR were no different for inhaled loxapine + IM lorazepam and each agent alone over a 12‐h postdose period. Although the central nervous system sedative effects were observed for each treatment in healthy volunteers, the effect was greater following concomitant lorazepam 1 mg IM + inhaled loxapine 10 mg administration. There were no deaths, serious AEs, premature discontinuations due to AEs, or treatment‐related AEs.

Efavirenz modulation of sleep spindles and sleep spectral profile.

Non-nucleoside reverse transcriptase inhibitors are important antiretroviral agents for the treatment of human immunodeficiency virus. Some non-nucleoside reverse transcriptase inhibitors, in particular efavirenz, have prominent effects on sleep, cognition and psychiatric variables that limit their tolerability. To avoid confounds due to drug-drug and drug-disease interactions, we assessed the effects of efavirenz in healthy volunteers on sleep, cognition and psychological endpoints during the first week of treatment. Forty healthy male subjects were randomized to receive placebo or efavirenz 600 mg nightly for 7 days after completion of a 3-day placebo run-in period. Treatment with efavirenz was associated with reduced time to sleep onset in the Maintenance of Wakefulness Test, an increase in non-rapid eye movement sleep, a large exposure-related decrease in sigma band spectral density and sleep spindle density during non-rapid eye movement sleep, and reduced performance on an attention switching task. Because efavirenz has been shown to have serotonin 2A receptor partial-agonist properties, we reasoned that antagonism of serotonin 2A receptor signalling in the thalamic reticular nucleus, which generates sleep spindles and promotes attention, may be responsible. Consistent with predictions, treatment of healthy volunteers with a single dose of a serotonin 2A receptor antagonist was found to significantly suppress sigma band spectral density in an exposure-related manner and modulated the overall spectral profile in a manner highly similar to that observed with efavirenz, consistent with the notion that efavirenz exhibits serotonin 2A receptor partial-agonist pharmacology in humans.

EPA-0380 – Effects of agomelatine and escitalopram on emotional detachment, emotional processing and motivation during a 9-week treatment in healthy volunteers

Dysfunctions of the emotion processing circuitry are associated with Major Depressive Disorder (MDD) and can be modulated by antidepressants like selective serotonin reuptake inhibitors (SSRIs). Moreover, motivation, pleasure or interest are important neuropsychological states of emotional life, and are known to be impaired in MDD patients. Under SSRIs, some patients report decreases in motivation and/or in emotional responsiveness commonly described as emotional detachment (Corruble E et al , 2013) and having significant impact on drug compliance and quality of life. The antidepressant agomelatine displays a unique neurochemical profile, different from SSRIs, being a MT1/MT2 receptors agonist and a 5HT2C receptors antagonist (De Bodinat C et al , 2010). Data from healthy volunteers and patients suggest that agomelatine is associated with less emotional detachment as compared to SSRIs notably with a more specific action in the facial expression recognition task (Harmer CJ et al , 2011), lower scores on scales for blunting (Corruble E et al , 2013), and absence of sexual dysfunction (Montejo AL et al , 2010). Here, the effects of two antidepressants, agomelatine (25 and 50mg) and escitalopram (10–20mg) on emotional detachment, emotional processing, motivation and sexual function were assessed during a 9-week randomised, double-blind, placebo-controlled, parallel-designed study in healthy male and female volunteers aged between 18-45 years. A battery of neuropsychological and motivation tasks/questionnaires available in the literature were used. Investigating antidepressant effects on key psychological processes in healthy volunteers allows elucidation of the direct actions of antidepressants unconfounded by changes in mood symptoms. The study is on progress.

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Alter the Hematopoietic Niche and Treatment In Healthy Volunteers Results In Mobilization of CD34+ Cells, Hematopoietic Colony Forming Cells, and Endothelial Colony Forming Cells

AbstractAbstract 556Bone and bone marrow are dynamic tissues with specialized niches that support numerous bone derived stem and progenitor cells with hematopoietic, mesenchymal and endothelial potentials. These niches are comprised of osteoblasts, stromal cells and an extracellular matrix of collagens, fibronectin and proteoglycans. Osteoblasts (OB) lining the endosteum are a significant regulatory component of hematopoiesis and numerous studies have demonstrated that stem cells reside in close proximity to OB. Prostaglandin E2 (PGE2) is an abundant lipid mediator that exerts numerous activities including inhibition of myelopoiesis and regulation of hematopoietic stem cell self-renewal, and is also a positive regulator of OB number and activity. We investigated the therapeutic potential of inhibiting PGE2 biosynthesis via NSAID administration to expand progenitor cells and disrupt the bone marrow niche in order to facilitate stem and progenitor cell mobilization. Mice were treated with NSAID for 1–4 days, and femurs analyzed for OB and stem and progenitor content. Endosteal OB lining both bony trabeculae and cortical bone in the diaphyseal and epiphyseal regions of the femur demonstrated a time dependent “flattening”, as determined by width measurement of 50 random OB per femur (2.82 to 1.45 microns after 4 days, P<0.001; n=4-5 femurs/group). Flushed bones were further subjected to sequential collagenase digestions and assessed for CD45- CD31- TER119- Sca-1- osteopontin (OPN)+ OB and for the Sca-1+ c-kit+ Lin- (SKL) and CD150+ CD48- SKL (SLAM SKL) hematopoietic cell populations. NSAID treatment resulted in a significant reduction in OPN+ OB (24±3%, P<0.05), and an increase in endosteal SKL and SLAM SKL (1.7±0.1 and 1.9±0.1 fold, respectively; P<0.05). This niche disruption directly correlated with an increase in hematopoietic stem and progenitor cell (HSPC) mobilization in mice and in peripheral CD34+ cells in baboons (2.07±0.12 fold, P<0.01). To determine if NSAIDs are also capable of HSPC mobilization in humans, peripheral blood (PB) of 7 healthy volunteers was analyzed for CD34+ cells by the ISHAGE protocol, and CFU-GM, BFU-E and CFU-GEMM in methylcellulose culture, before and after a 5 day regimen of the NSAID meloxicam. Meloxicam treatment resulted in significant mobilization of CD34+ cells, CFU-GM and CFU-GEMM (2.0±0.5, 3.8±0.9 and 3.4±0.7 fold, respectively; P<0.05) with no change in BFU-E, consistent with the erythropoietic stimulatory effect of PGE2. In addition to hematopoiesis, marrow progenitors are also implicated in neoangiogenesis. Endothelial progenitors are found in mouse bone marrow and blood, and in the CD34+ adult and cord blood populations, and can be mobilized by ischemic injury and various cytokines and growth factors. Utilizing a functional approach to define a rare population of circulating endothelial colony forming cells (ECFC) we previously described (Yoder et al., 2007, Blood), we assessed the level of ECFC in volunteers before and after meloxicam administration. Only 4/7 volunteers had detectable ECFC in 40 mL of blood before treatment, while 7/7 had detectable ECFC post-meloxicam. In addition, NSAID treatment increased ECFC number and reduced culture time to first ECFC detection. These data demonstrate that NSAID administration alters the bone marrow niche and mobilizes both hematopoietic and endothelial progenitors to PB. This provides a safe and effective strategy that can be easily added to existing mobilization regimens to improve efficacy. We also report for the first time the ability of NSAIDs to increase peripheral ECFC; perhaps suggesting an exciting possible mechanism, in addition to inhibition of platelets, for the beneficial effects of NSAIDs like aspirin on the cardiovascular system. It is interesting to note that the highly COX2 selective NSAID valdecoxib was recently withdrawn from the market due to adverse cardiovascular events, and our studies demonstrate that valdecoxib is unable to mobilize progenitors from the bone marrow, while aspirin is highly effective, possibly explaining some of the cardiovascular differences between these two compounds. Future pre-clinical and clinical studies utilizing NSAID administration, with and without other agents, are likely to lead to new strategies for acquisition of bone marrow derived hematopoietic and endothelial progenitors. Disclosures:No relevant conflicts of interest to declare.

Effects of short-term and long-term danazol treatment on lipoproteins, coagulation, and progression of atherosclerosis: Two clinical trials in healthy volunteers and patients with hereditary angioedema

Background: Danazol is a synthetic androgen derivative frequently used as prophylaxis in patients with hereditary angioedema (HAE) due to complement-1 esterase inhibitor deficiency. However, danazol has been reported to decrease high-density lipoprotein cholesterol (HDL-C) levels and to adversely affect coagulation parameters, which are considered to be proatherothrombotic. Objective: The short- and long-term effects of danazol were evaluated on proatherogenic intermediate end points in healthy volunteers and patients with HAE. Methods: Short-term effects were evaluated in healthy men randomly assigned to 200 mg/d of danazol or placebo for 4 weeks in a crossover trial with no washout period. Long-term effects of danazol on lipoproteins, coagulation, and carotid intima-media thickness (CIMT) were evaluated in a cross-sectional study in which patients with HAE treated with danazol, a mean dose of 170 mg/d for ≥2 years, were compared with healthy controls matched for age, sex, and body mass index (BMI). Drug tolerability was assessed by questionnaires and adherence was measured by pill count whendrug bottles were returned after every study visit. Results: Patients in the short-term study were 15 men with a mean (SD) age of 32.6 (6.9) years and BMI of 24.3 (4.1) kg/m 2. In the long-term study, patients with HAE were 10 women and 7 men with a mean (SD) age of 41.1 (12.9) years and BMI of 25.4 (2.6) kg/m 2; the 17 matched controls had a mean (SD) age of 39.8 (11.8) years and BMI of 25.4 (2.6) kg/m 2. Short-term danazol treatment was associated with a decrease from baseline in apolipoprotein A-I of 21% and in HDL-C of 23%. Flow-mediated dilation and coagulation parameters were unaffected after 4 weeks. Longterm danazol treatment did not adversely affect HDL-C concentration (1.1 [0.5] vs baseline, 1.2 [0.5] pmol/L), HDL-related transfer proteins such as paraoxonase-1 activity (92 [62] vs 80 [40] U/mM), cholesteryl-ester transfer protein mass (1.5 [0.4] vs 2.2 [0.6] µg/mL), lecithin cholesterol acyltransferase activity (21.2 [4.5] vs 32.1 [7.2] nmol CE · mL -1 · h -1), plasma phospholipid transfer protein activity (15.4 [1.5] vs 14.9 [1.2] AU), and apolipoproteins between patients with HAE and controls. The mean (SD) CIMT was similar between patients with HAE and controls (0.62 [0.09] vs 0.59 [0.08] mm; P = NS). However, HAE patients using danazol had increased coagulation activation when compared with controls (prothrombin fragments, 286 [119] vs 164 [57] pmol/L, P = 0.002; thrombinantithrombin complex, 3.9 [1.4] vs 2.6 [1.1] µg/L, P = 0.01). Conclusions: Short-term danazol treatment in healthy volunteers was associated with a reduction in HDL-C levels without a significant effect on endothelial function or coagulation parameters. In contrast, patients with HAE treated for >2 years with danazol had increased activation of coagulation, but there were no significant differences in HDL-C or CIMT compared with matched healthy controls.

Is the New Point-of-Care Test VerifyNow® Aspirin Able To Identify Aspirin Resistance Using the Recommended Cut-Off?.

Low dose aspirin inhibits platelet aggregation and is widely used in the treatment of cardiovascular disease. However, a considerable interindividuel variation in response to aspirin has been reported. Some studies suggest that patients with inadequate platelet inhibition by aspirin are at increased risk of suffering future cardiovascular events. Identification of these patients is of great interest. So far there is no consensus regarding the choice of method and definition for identifying patients with inadequate response to aspirin treatment, also referred to as aspirin resistance (AR). The VerifyNow® Aspirin system is a new point-of-care method for measurement of platelet aggregation response to aspirin. The main objectives were:1.to determine the repeatability of VerifyNow® Aspirin2.to determine the agreement between VerifyNow® and light transmission aggregometry (LTA) - the considered reference method3.to determine the frequency of AR defined by the two methods.We included 21 healthy volunteers and 40 patients with documented coronary artery disease. Duplicate measurements of platelet aggregation were performed with VerifyNow® Aspirin and LTA (agonist arachidonic acid 1.0 mM) in healthy volunteers before onset of aspirin treatment. After treatment of healthy volunteers with plain aspirin 75 mg daily for 7 days steady state was reached, and duplicate platelet aggregation measurements were performed once a day for four consecutive days in both healthy subjects and patients during continued treatment with plain aspirin 75 mg daily. Test results were expressed in Aspirin Reaction Units (ARU) using VerifyNow® Aspirin and in percent of max aggregation with LTA. The cut-off for determining AR was ≥ 550 ARU for VerifyNow® and ≥ 20% for LTA. To confirm compliance we measured serum-thromboxaneB2 (se-TXB2) levels. All participants were compliant to aspirin treatment as measured by se-TXB2; < 4,5 ng/mL 99% suppression. All duplicate analyses with VerifyNow® showed a high degree of repeatability as the coefficient of variance prior to aspirin treatment was 0.5% and 3.0% during aspirin treatment. Correlation of measurements of platelet aggregation during aspirin therapy with VerifyNow® and LTA respectively was moderate, Spearmans ρ=0.50. The agreement between the two methods regarding identification of individuals with AR was poor: According to VerifyNow® Aspirin none of the participants had AR, whereas LTA identified 7 (12%) subjects with AR. We performed ROC analysis using LTA as reference method. We found poor sensitivity and good specificity when using 550 ARU as a cut-off, table.ROC statistics on VerifyNow AR cut-off with LTA as referenceVerifyNow cut-offSensitivity, %Specificity, %≥ 460 ARU10072≥ 480 ARU4380≥ 500 ARU3091In conclusion we found that VerifyNow® Aspirin showed a very high repeatability, but correlated only moderately well with LTA. In 100% compliant participants treated with a low dose of aspirin 75 mg daily we found that none of the study participants were classified as AR with VerifyNow® Aspirin, but 12% were identified as AR by LTA. Our results imply that the recommended cut-off level at 550 ARU for identifying AR with VerifyNow® Aspirin is too high. Further studies are needed to investigate the relevance of a cut-off level lower than 550 ARU for determining AR and its clinical implications.

Limited cognitive benefits in Stage +2 postmenopausal women after 6 weeks of treatment with Ginkgo biloba

Gingko biloba has cognitive benefits both in populations suffering from dementia and after acute treatment in healthy volunteers, with some evidence indicating that those with poorer cognitive performance show greater benefit. We have previously found that 1 week of treatment with ginkgo improved attention, memory and mental flexibility in post-menopausal women, but the evidence for any beneficial effects of longer treatment is less well-established. The present study aimed to determine whether cognitive benefits, similar to those previously found after 1 week of treatment, would persist after 6 weeks of treatment, and whether those with poorer cognitive performance would benefit more. In a placebo-controlled, double-blind study, postmenopausal women (aged 51-67 years) were randomly allocated to receive a standardized extract of ginkgo (LI 1370, Lichtwer Pharma, Marlow, UK) (one capsule/day of 120 mg, n = 45) or matching placebo (n = 42) for 6 weeks. According to an established reproductive staging system, subjects were divided into those in the early (Stage +1; mean age 55 years) and late (Stage +2: mean age 61 years) stages of menopause. At baseline and after 6 weeks of treatment, subjects completed tests of mental flexibility, planning, memory and sustained attention, and ratings of mood, sleepiness, bodily and menopausal symptoms. The only significant effects of ginkgo were in the test of mental flexibility, in which there were significant menopausal stage-ginkgo interactions. This was because subjects in Stage +2 required fewer trials to complete the task and made fewer errors after ginkgo treatment, whereas those in Stage +1 showed no benefits. Subjects in Stage +2 had poorer performance at baseline compared to those in Stage +1 both in this task and the test of planning ability. The beneficial effects of ginkgo were limited to the test of mental flexibility and to those with poorer performance.

Effects of furosemide and bendroflumethiazide on saliva flow rate and composition

Aim of this study was to evaluate the effect on saliva flow rate and composition and on perceived xerostomia. The study used a Latin square design, all subjects being once daily (at 7.00 a.m.) taking the bendroflumethiazide (2.5 mg), furosemide (40 mg), or placebo, in a randomised order. Each treatment period of 7 days was separated by wash-out periods of 14 days. Unstimulated and paraffin chewing stimulated whole saliva, and 3% citric acid stimulated parotid and submandibular–sublingual secretion were collected twice daily, at 7.30 a.m., with the patients in a fasting condition (morning values), and at 10.30 a.m., about 2 h after intake of a standard breakfast (lunchtime values), on day 0 (baseline), day 1 (acute treatment), and day 7 (chronic treatment). Saliva flow rates were measured and all four secretions were analysed for the concentration of sodium, potassium, chloride, and total protein. Xerostomia was assessed by means of a Visual Analogue Scale. Statistical analysis used the Wilcoxon signed rank test. For flow rate, only that of submandibular–sublingual secretion was affected, significantly so in the morning during chronic treatment with both drugs. In resting whole saliva the output of both sodium and chloride tended to decrease especially during treatment with bendroflumethiazide, while in submandibular–sublingual secretion the output of all the electrolytes was decreased, especially for potassium and chloride and during treatment with furosemide. Further, xerostomia tended to increase during treatment with furosemide, statistically significant at lunchtime during chronic treatment. In conclusion, this study has demonstrated a modest effect on salivary flow rate and a more pronounced effect on saliva composition, especially in submandibular–sublingual secretion during treatment of healthy volunteers with therapeutic doses of two different diuretics, encouraging clinical studies in hypertensive patients and basic research as to the presence of a thiazide sensitive Na–Cl cotransporter in human salivary glands.

Tiotropium bromide. A review of its use as maintenance therapy in patients with COPD.

Tiotropium bromide. A review of its use as maintenance therapy in patients with COPD.

Hyperglycemic Clamp Assessment of Insulin Secretory Responses in Normal Subjects Treated with Olanzapine, Risperidone, or Placebo

The goal of this study was to evaluate the effect of olanzapine or risperidone treatment on beta-cell function in healthy volunteers. Subjects were randomly assigned to single-blind therapy with olanzapine (10 mg/d; n = 17), risperidone (4 mg/d; n = 13), or placebo (n = 18) for 15-17 d. Insulin secretion was quantitatively assessed at baseline and the end of the study period using the hyperglycemic clamp. Weight increased significantly (P < 0.01) in the olanzapine (2.8 +/- 1.7 kg) and risperidone (3.1 +/- 2.1 kg) treatment groups. An increase ( approximately 25%) in the insulin response to hyperglycemia and a decrease ( approximately 18%) in the insulin sensitivity index were observed after treatment with olanzapine and risperidone. The change in insulin response was correlated (r = 0.5576; P = 0.019) with a change in body mass index. When the impact of weight change was accounted for by multivariate regression analyses, no significant change in insulin response or insulin sensitivity was detected after treatment with olanzapine or risperidone. We found no evidence that treatment of healthy volunteers with olanzapine or risperidone decreased the insulin secretory response to a prolonged hyperglycemic challenge. The results of this study do not support the hypothesis that olanzapine or risperidone directly impair pancreatic beta-cell function.

Hyperglycemic Clamp Assessment of Insulin Secretory Responses in Normal Subjects Treated with Olanzapine, Risperidone, or Placebo

The goal of this study was to evaluate the effect of olanzapine or risperidone treatment on β-cell function in healthy volunteers. Subjects were randomly assigned to single-blind therapy with olanzapine (10 mg/d; n = 17), risperidone (4 mg/d; n = 13), or placebo (n = 18) for 15–17 d. Insulin secretion was quantitatively assessed at baseline and the end of the study period using the hyperglycemic clamp. Weight increased significantly (P < 0.01) in the olanzapine (2.8 ± 1.7 kg) and risperidone (3.1 ± 2.1 kg) treatment groups. An increase (∼25%) in the insulin response to hyperglycemia and a decrease (∼18%) in the insulin sensitivity index were observed after treatment with olanzapine and risperidone. The change in insulin response was correlated (r = 0.5576; P = 0.019) with a change in body mass index. When the impact of weight change was accounted for by multivariate regression analyses, no significant change in insulin response or insulin sensitivity was detected after treatment with olanzapine or risperidone. We found no evidence that treatment of healthy volunteers with olanzapine or risperidone decreased the insulin secretory response to a prolonged hyperglycemic challenge. The results of this study do not support the hypothesis that olanzapine or risperidone directly impair pancreatic β-cell function.

Erythropoetin treatment can increase 2,3-diphosphoglycerate levels in red blood cells

Some patients experience an improved well-being during treatment with recombinant human erythropoietin even with an unchanged Hb level. We have hypothesized that this may not be only a placebo effect. 2,3-diphosphoglycerate (2,3-DPG) in red blood cells increases in response to anaemia/hypoxia and causes a shift of the oxygen dissociation curve, allowing a more effective oxygen delivery. We have investigated red cell 2,3-DPG concentrations during erythropoietin treatment in healthy volunteers as a mediator of a possible physiological explanation. Thirteen healthy subjects with no iron deficiency were recruited and randomly assigned to a treatment group comprising five males and three females and a control group including three males and two females. The treatment group was treated with erythropoietin (Recormon®), 20 IE/kg subcutaneously three times/week for 4 weeks. Blood samples were collected at each injection day and 10 days after the last injection and at corresponding times in the control group. B-Hb, red cell 2,3-DPG and P50 were measured by standard techniques and oxygen-releasing capacity was calculated. Results

Thalidomide and the immune system. 4. Down-regulation of the CD26 receptor, probably involved in the binding of HIV components to T cells in primates

Thalidomide (Thd) is capable of down-regulating the CD26 receptor on CD4 + lymphocytes after treatment of healthy volunteers. Similar effects are observed when marmosets ( Callithrix jacchus) are treated with Thd. The Ta 1 epitope of the CD26 receptor has recently been shown to bind the HIV-1 Tat trans-activating protein, and CD26 has also been suggested to be a coreceptor for the binding of the V3 loop of the gp120 HIV envelope protein. This might provide a hint for possible therapeutic interventions.

Pharmacodynamic effects of chronic yohimbine treatment in healthy volunteers

The effects of 14 days of treatment with the alpha 2-adrenoceptor antagonist yohimbine on cardiovascular parameters (blood pressure and heart rate), plasma catecholamines, insulin and non-esterified fatty acids (NEFA), and the number of alpha 2-adrenoceptors on platelets have been evaluated. The treatment increased plasma noradrenaline but not adrenaline and did not change the other cardiovascular, metabolic or routine blood parameters. It caused a decrease in the velocity of adrenaline-induced platelet aggregation, although [3H]-yohimbine binding to platelets remained unchanged. Acute administration of yohimbine before the experiment led to a significant increase in plasma noradrenaline and NEFA levels. After the 15 day treatment, acute administration of the same dose of yohimbine had less effect on plasma NEFA and there was no significant change in plasma noradrenaline. The acute lipid-mobilizing effect of yohimbine in healthy volunteers persisted after the 14 days of treatment with no change in other parameters. The prolonged alpha 2-adrenoceptor blockade with yohimbine did not induce any change in platelet alpha 2-adrenoceptors.