The Effects of 4-Methylethcathinone on Conditioned Place Preference, Locomotor Sensitization, and Anxiety-Like Behavior: A Comparison with Methamphetamine.

BACKGROUND: 4-Methylethcathinone is a drug that belongs to the second generation of synthetic cathinones, and recently it has been ranked among the most popular "legal highs". Although it has similar in vitro neurochemical actions to other drugs such as cocaine, the behavioral effects of 4-methylethcathinone remain to be determined. METHODS: The addictive potential and locomotor potentiation by 4-methylethcathinone were investigated in rats using the conditioned place preference and sensitization paradigm. Methamphetamine was used as a positive control. Because synthetic cathinones can have psychological effects, we also examined anxiety-like behavior using the elevated plus maze. RESULTS: A conditioning dose of 10 mg/kg 4-methylethcathinone was able to induce conditioned place preference and reinstatement (following 2 weeks of withdrawal). Acute or repeated injections of 4-methylethcathinone at 3 or 10mg/kg failed to alter locomotor activity. At 30 mg/kg, however, acute 4-methylethcathinone increased locomotor activity compared with saline, while chronic 4-methylethcathinone induced a delayed and attenuated sensitization compared with methamphetamine. Additionally, repeated daily injections of 4-methylethcathinone (30 mg/kg) reduced, whereas methamphetamine increased time spent by rats in the open arm of an elevated plus maze compared with saline injections. Interestingly, a 2-week withdrawal period following chronic injections of 4-methylethcathinone or methamphetamine increased time spent in the open arm in all rats. CONCLUSIONS: The rewarding properties of 4-methylethcathinone were found to be dissociated from its effects on locomotor activity. Additionally, chronic 4-methylethcathinone use may trigger abnormal anxious behaviors. These behavioral effects caused by 4-methylethcathinone appear to last even after a withdrawal period.

[Development and evaluation of a quantitative double antibodies sandwich ELISA assay for rIFN-alpha1b].

OBJECTIVE: To develop a double antibody sandwich ELISA assay for quantitative determination of recombinant human interferon alpha1b. METHODS: Mouse monoclonal antibodies with different binding site on rIFN-alpha1b were screened to select optimized candidates as coating and HRP-labeled index antibodies respectively. And a double antibodies sandwich ELISA was assembled; the reliable lower detection limit, specificity, accuracy and reproducibility were evaluated and validated. RESULTS: The quantitative sandwich ELISA had a reliable lower detection limit of 10 ng/ml, with a liner detection range 10-100 ng/ml (R2 = 0.992), variation coefficient inter-plates is less than 10%. CONCLUSION: The developed sandwich ELISA was a sensitive and specific, accuracy and reproducibility method for quantitative determination of recombinant human interferon alpha1b in final product.

[Preparation and application of monoclonal antibodies to recombinant human IFN alpha].

OBJECTIVE: To prepare and apply monoclonal antibodies (McAb) against recombinant human interferon alpha (rHu IFN-alpha). METHODS: Five cell lines (2E9, 4G1, 2A7, 2C9, 4G10) secreting McAbs against rHu IFN-alpha were established by hybridoma technique. RESULTS: All the cell lines secreted monoclonal antibodies stably. Functions of secreting antibodies of the five cell lines lasted for 6 months in BALB/c mice and 8 months in cell culture. The specificity of antibody was constant. The Ig subclasses of the McAbs were IgG1. Anti-IFN McAb affinity purification column was prepared by coupling the anti IFN-alpha McAb to Sepharose 4B. The combining rate reached was higher than 95%. CONCLUSIONS: The highest purification efficiency was obtained by using 4G10 column.