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The unique pharmacological properties of δ-containing γ-aminobutyric acid type A receptors (δ-GABAARs) make them an attractive target for selective and persistent modulation of neuronal excitability. However, the availability of selective modulators targeting δ-GABAARs remains limited. AA29504 ([2-amino-4-(2,4,6-trimethylbenzylamino)-phenyl]-carbamic acid ethyl ester), an analog of K+ channel opener retigabine, acts as an agonist and a positive allosteric modulator (Ago-PAM) of δ-GABAARs. Based on electrophysiological studies using recombinant receptors, AA29504 was found to be a more potent and effective agonist in δ-GABAARs than in γ2-GABAARs. In comparison, AA29504 positively modulated the activity of recombinant δ-GABAARs more effectively than γ2-GABAARs, with no significant differences in potency. The impact of AA29504's efficacy- and potency-associated GABAAR subtype selectivity on radioligand binding properties remain unexplored. Using [3H]4'-ethynyl-4-n-propylbicycloorthobenzoate ([3H]EBOB) binding assay, we found no difference in the modulatory potency of AA29504 on GABA- and THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol)-induced responses between native forebrain GABAARs of wild type and δ knock-out mice. In recombinant receptors expressed in HEK293 cells, AA29504 showed higher efficacy on δ- than γ2-GABAARs in the GABA-independent displacement of [3H]EBOB binding. Interestingly, AA29504 showed a concentration-dependent stimulation of [3H]muscimol binding to γ2-GABAARs, which was absent in δ-GABAARs. This was explained by AA29504 shifting the low-affinity γ2-GABAAR towards a higher affinity desensitized state, thereby rising new sites capable of binding GABAAR agonists with low nanomolar affinity. Hence, the potential of AA29504 to act as a desensitization-modifying allosteric modulator of γ2-GABAARs deserves further investigation for its promising influence on shaping efficacy, duration and plasticity of GABAAR synaptic responses. [ABSTRACT FROM AUTHOR]

OBJECTIVES: A prospective study was undertaken to compare the efficacy of everolimus versus azathioprine or placebo in maintaining steroid-induced remission in active Crohn's disease (CD) and assess the safety and pharmacokinetics of everolimus. METHODS: This was a randomized, double-blind, placebo-controlled, proof-of-concept study in adults with moderate-to-severe active CD. The patients received oral steroids for a rapid induction of remission plus everolimus 6 mg/day, azathioprine 2.5 mg/kg/day, or placebo as maintenance treatment. The main outcome measure was the treatment success, defined as a steroid-free remission by the end of month 3 and maintained until study cutoff without the use of prohibited efficacy treatments. RESULTS: Following an interim analysis, the study was terminated before enrollment was completed due to the lack of efficacy. The full intent-to-treat population comprised 138 patients. Only 96 patients who entered the study ≥7 months prior to data cutoff were included in the primary efficacy population. The treatment success was achieved in 13 of 38 everolimus patients, 22 of 36 azathioprine patients, and 8 of 22 placebo patients. Using the Kaplan–Meier estimates at month 7, the incidence of treatment success was 22.0% with everolimus group (95% confidence interval [CI] 6.7–37.3%, P= 0.610 vs placebo), 38.3% with azathioprine group (95% CI 20.6–55.9%, P= 0.500 vs placebo), and 28.8% with placebo group (95% CI 7.7–49.9%). The type and incidence of adverse events in the everolimus cohort were similar to those reported in the approved transplantation indications. CONCLUSIONS: The safety and tolerability of everolimus (6 mg/day) in patients with active CD were comparable to azathioprine. At this dose, everolimus is not more efficacious in achieving a steroid-free remission in active CD than the comparators. [ABSTRACT FROM AUTHOR]

In a 5-year study involving 119 postmenopausal women, zoledronic acid 4 mg given once-yearly for 2, 3 or 5 years was well tolerated with no evidence of excessive bone turnover reduction or any safety signals. BMD increased significantly. Bone turnover markers decreased from baseline and were maintained within premenopausal reference ranges. After completion of the core study, two consecutive, 2-year, open-label extensions investigated the efficacy and safety of zoledronic acid 4 mg over 5 years in postmenopausal osteoporosis. In the core study, patients received 1 to 4 mg zoledronic acid or placebo. In the first extension, most patients received 4 mg per year and then patients entered the second extension and received 4 mg per year or calcium only. Patients were divided into three subgroups according to years of active treatment received (2, 3 or 5 years). Changes in BMD and bone turnover markers (bone ALP and CTX-I) were assessed. All subgroups showed substantial increases in BMD and decreases in bone markers. By the end of the core study, 37.5% of patients revealed a suboptimal reduction (< 30%) of bone ALP levels. After subsequent study drug administration during the extensions, there was no evidence of progressive reduction of bone turnover markers. Furthermore, increased marker levels after treatment discontinuation demonstrates preservation of bone remodelling capacity. This study showed that zoledronic acid 4 mg once-yearly was well tolerated and effective in reducing biomarkers over 5 years. Detailed analysis of bone marker changes, however, suggests that this drug regimen causes insufficient reduction of remodelling activity in one third of patients. [ABSTRACT FROM AUTHOR]

α-lipoic acid (α-LA) is an antioxidant used for the treatment of a variety of diseases, including liver cirrhosis, heavy metal poisoining, and diabetic polyneuropathy. In addition to its protective effect against oxidative stress, α-LA induces apoptosis in different cancer cells types. However, whether α-LA acid induces apoptosis of hepatoma cells is unknown. Herein, we investigated whether α-LA induces apoptosis in two different hepatoma cell lines FaO and HepG2. The results showed that α-LA inhibits the growth of both cell lines as indicated by the reduction in cell number, the reduced expression of cyclin A and the increased levels of the cyclin/CDKs inhibitors, p27Kip1 and p21Cip1. Cell cycle arrest was associated with cell loss, and DNA laddering indicative of apoptosis. Apoptosis was preceded by increased generation of reactive oxygen species, and associated with p53 activation, increased expression of Bax, release of cytochrome c from mitochondria, caspases activation, decreased levels of survivin, induction of pro-apoptotic signaling (i.e JNK) and inhibition of anti-apoptotic signaling (i.e. PKB/Akt) pathways. In conclusion, this study provides evidence that α-LA induces apoptosis in hepatoma cells, describes a possible sequence of molecular events underlying its lethal effect, and suggests that it may prove useful in liver cancer therapy. [ABSTRACT FROM AUTHOR]

[18F]FDG has been used as an inflammation marker and shown to accumulate in inflammatory atherosclerotic plaques. The aim of this study was to investigate the uptake and location of [18F]FDG in atherosclerotic plaque compartments. The biodistribution of intravenously administered [18F]FDG was analysed in atherosclerotic LDLR/ApoB48 mice ( n=11) and control mice ( n=9). Digital autoradiography was used to detect the ex vivo distribution in frozen aortic sections. In vitro binding of [18F]FDG in human atherosclerotic arteries was also examined. The uptake of [18F]FDG was significantly higher in the aorta of atherosclerotic mice as compared with the control mice. Autoradiography of excised arteries showed higher [18F]FDG uptake in the plaques than in the healthy vessel wall (mean ratio ±SD 2.7±1.1). The uptake of [18F]FDG in the necrotic, calcified sites of the advanced atherosclerotic lesions was 6.2±3.2 times higher than that in the healthy vessel wall. The in vitro studies of human arterial sections showed marked binding of [18F]FDG to the calcifications but not to other structures of the artery wall. In agreement with previous studies, we observed [18F]FDG uptake in atherosclerotic plaques. However, prominent non-specific binding to calcified structures was found. This finding warrants further studies to clarify the significance of this non-specific binding in human plaques in vivo. [ABSTRACT FROM AUTHOR]

The product of the MDR1 gene (P-gp) has been implicated in the transport of cholesterol from plasma membrane to endoplasmic reticulum for esterification. In previous studies on leukemia cell lines, we suggested that cholesterol esterification may regulate the rate of cell growth and that the MDR1 gene might be involved in this process by modulating intracellular cholesterol esters levels. To further investigate this matter, the rate of cell growth, cholesterol metabolism, expression of the MDR1 gene, and P-gp activity were compared in KB cell lines displaying differences in expression and function of P-gp (drug-sensitive phenotype versus MDR phenotype). The rate of cell growth correlated with cholesterol esterification in all KB cell lines, whereas the over-expression of MDR1 observed in the MDR cell lines was not always associated with an increased capacity of cells to esterify cholesterol. Two known inhibitors of P-gp activity, progesterone and verapamil, strongly inhibited both cholesterol esterification and cell proliferation in all KB cell lines, but they affected intracellular accumulation of labeled vinblastine only in MDR cell lines. These results further support a role for cholesterol esters in the regulation of cell growth and suggest that the P-gp expressed in MDR KB cells is not involved in the general process leading to cholesterol esterification. [ABSTRACT FROM AUTHOR]