Methocinnamox (MCAM), a mu opioid receptor antagonist with a long duration of action, attenuates heroin self-administration in rhesus monkeys, suggesting it could be an effective treatment for opioid use disorder (OUD). This study examined effects of acute and repeated MCAM administration on self-administration of the high-efficacy mu opioid receptor agonist fentanyl and characterized MCAM pharmacokinetics. Four rhesus monkeys self-administered i.v. infusions of fentanyl (0.00032 mg/kg/infusion) or cocaine (0.032 mg/kg/infusion). MCAM (0.1-0.32 mg/kg) or the opioid receptor antagonist naltrexone (0.001-0.032 mg/kg) was injected prior to test sessions to evaluate acute effects. On a separate occasion, 0.32 mg/kg MCAM was injected every 12 days for 5 total injections to evaluate the effectiveness of repeated treatment. Following acute injection, MCAM and naltrexone decreased fentanyl self-administration on the day of treatment, with attenuation lasting for up to 2 weeks after the larger MCAM dose and <1 day after naltrexone. Repeated MCAM administration decreased fentanyl self-administration for more than 2 months without altering cocaine self-administration. MCAM plasma concentrations peaked 15-45 min after injection, with a half-life ranging from 13.7 to 199.8 min, and decreased markedly 1 day after injection. MCAM selectively reduced opioid self-administration and remained effective with repeated administration. Moreover, MCAM was effective at times when plasma levels were very low, suggesting that pharmacodynamic (i.e., pseudoirreversible binding to mu opioid receptors) and not pharmacokinetic factors play a significant role in its long-lasting effects. Taken together with previous studies, these data indicate that MCAM could be a safe, effective, and longacting treatment for OUD.
Clinical evidence indicates brain serotonin (5-HT) stores and neurotransmission may be inadequate in subpopulations of individuals with autism, and this may contribute to characteristically impaired social behaviors. Findings that depletion of the 5-HT precursor tryptophan (TRP) worsens autism symptoms support this hypothesis. Yet dietetic studies show and parents report that many children with autism consume less TRP than peers. To measure the impact of dietary TRP content on social behavior, we administered either diets devoid of TRP, with standard TRP (0.2 gm%), or with 1% added TRP (1.2 gm%) overnight to three mouse strains. Of these, BTBRT+Itpr3tf/J and 129S1/SvImJ consistently exhibit low preference for social interaction relative to C57BL/6. We found that TRP depletion reduced C57BL/6 and 129S social interaction preference, while TRP enhancement improved BTBR sociability (p < 0.05; N= 8–10). Subsequent marble burying was similar regardless of grouping. After behavior tests, brain TRP levels and plasma corticosterone were higher in TRP enhanced C57BL/6 and BTBR, while 5-HT levels were reduced in all strains by TRP depletion (p <0.05; N= 4 −10). Relative hyperactivity of BTBR and hypoactivity of 129S, evident in self-grooming and chamber entries during sociability tests, were uninfluenced by dietary TRP. Our findings demonstrate mouse sociability and brain 5-HT turnover are reduced by acute TRP depletion, and can be enhanced by TRP supplementation. This outcome warrants further basic and/or clinical studies employing biomarker combinations such as TRP metabolism and 5-HT regulated hormones to characterize the conditions wherein TRP supplementation can best ameliorate sociability deficits.
The recreational use of synthetic cannabinoids has recently increased. This increase is due, in part, to the recent availability of inexpensive compound sold legally online in bulk. In particular, JWH-018 (1-pentyl-3-(1-naphthoyl)indole) and JWH-073 (1-butyl-3-(1-naphthoyl)indole) have been found in herbal blends marketed as alternatives to cannabis. Although these particular compounds have recently been emergency scheduled in the United States, online suppliers have shifted sales to other, similar compounds that are not currently scheduled. However, the purity of the drugs obtained from online suppliers is not known. Relative purity of JWH-018 and JWH-073 from three different online suppliers was determined using high-performance liquid chromatography with ultraviolet detection and validated standards obtained from a traditional research chemical supplier. Our results show that JWH-018 and JWH-073 obtained from online vendors was of comparable purity to validated standards, even though the physical properties varied in color, texture, and odor. It is concluded that adverse events following consumption of synthetic cannabinoid preparations is unlikely to be due to impurities or residue from the manufacturing process, but rather to effects of the active drug or interactions with other psychoactive chemicals from herbs blended into products marketed as cannabis alternatives.
The pharmacokinetics of PEth 16:0/20:4 in whole blood samples is detectable after alcohol consumption and differs in amount synthesized and rate of elimination versus PEth 16:0/18:1 and 16:0/18:2. Measuring the concentrations of these 3 homologs has the potential to provide more information about the amount and time frame of alcohol consumption than any one alone.
The Breast Cancer Metastasis Suppressor 1 (BRMS1) belongs to an expanding category of proteins called metastasis suppressors that demonstrate in vivo metastasis suppression while still allowing growth of the orthotopic tumor. Since BRMS1 decreases either the expression or function of multiple mediators implicated in resistance to chemotherapy (NF-κB, AKT, EGFR), we asked whether breast carcinoma cells expressing BRMS1 could be sensitized upon exposure to commonly used therapeutic agents that inhibit some of these same cellular mediators as BRMS1. In this report, we demonstrate that chemosensitivity of breast cancer cells is preserved in the presence of BRMS1. Further, BRMS1 does not change expression of AKT isoforms or PTEN, implicated in chemoresistance to common drug agents. Overall, our data with two different metastatic breast cancer cell lines indicates that BRMS1 expression status may not interfere with the response to commonly used chemotherapeutic agents in the management of solid tumors such as breast cancer. Since tumor protein expression analysis increasingly guides therapy decisions, our data may be of clinical benefit in disease management including profiling for BRMS1 expression before start of therapy.Keywords breast cancer metastasis suppressor 1 (BRMS1); chemoresistance; 3D-culture; breast cancer; metastasis
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