Structure-activity relationship of pyrazol-4-yl-pyridine derivatives and identification of a radiofluorinated probe for imaging the muscarinic acetylcholine receptor M4

There is an accumulating body of evidence implicating the muscarinic acetylcholine receptor 4 (M4) in schizophrenia and dementia with Lewy bodies, however, a clinically validated M4 positron emission tomography (PET) radioligand is currently lacking. As such, the aim of this study was to develop a suitable M4 PET ligand that allows the non-invasive visualization of M4 in the brain. Structure-activity relationship studies of pyrazol-4-yl-pyridine derivates led to the discovery of target compound 12 - a subtype-selective positive allosteric modulator (PAM). The radiofluorinated analogue, [18F] 12, was synthesized in 28 ± 10% radiochemical yield, >37 GBq/μmol and an excellent radiochemical purity >99%. Initial in vitro autoradiograms on rodent brain sections were performed in the absence of carbachol and showed moderate specificity as well as a low selectivity of [18F] 12 for the M4-rich striatum. However, in the presence of carbachol, a significant increase in tracer binding was observed in the rat striatum, which was reduced by >60% under blocking conditions, thus indicating that orthosteric ligand interaction is required for efficient binding of [18F] 12 to the allosteric site. Remarkably, however, the presence of carbachol was not required for high specific binding in the non-human primate (NHP) and human striatum, and did not further improve the specificity and selectivity of [18F] 12 in higher species. These results pointed towards significant species-differences and paved the way for a preliminary PET study in NHP, where peak brain uptake of [18F] 12 was found in the putamen and temporal cortex. In conclusion, we report on the identification and preclinical development of the first radiofluorinated M4 PET radioligand with promising attributes. The availability of a clinically validated M4 PET radioligand harbors potential to facilitate drug development and provide a useful diagnostic tool for non-invasive imaging.

18FMAGL-4-11 positron emission tomography molecular imaging of monoacylglycerol lipase changes in preclinical liver fibrosis models

Monoacylglycerol lipase (MAGL) is a pivotal enzyme in the endocannabinoid system, which metabolizes 2-arachidonoylglycerol (2-AG) into the proinflammatory eicosanoid precursor arachidonic acid (AA). MAGL and other endogenous cannabinoid (EC) degrading enzymes are involved in the fibrogenic signaling pathways that induce hepatic stellate cell (HSC) activation and ECM accumulation during chronic liver disease. Our group recently developed an 18F-labeled MAGL inhibitor ([18F]MAGL-4-11) for PET imaging and demonstrated highly specific binding in vitro and in vivo. In this study, we determined [18F]MAGL-4-11 PET enabled imaging MAGL levels in the bile duct ligation (BDL) and carbon tetrachloride (CCl4) models of liver cirrhosis; we also assessed the hepatic gene expression of the enzymes involved with EC system including MAGL, NAPE-PLD, FAAH and DAGL that as a function of disease severity in these models; [18F]MAGL-4-11 autoradiography was performed to assess tracer binding in frozen liver sections both in animal and human. [18F]MAGL-4-11 demonstrated reduced PET signals in early stages of fibrosis and further significantly decreased with disease progression compared with control mice. We confirmed MAGL and FAAH expression decreases with fibrosis severity, while its levels in normal liver tissue are high; in contrast, the EC synthetic enzymes NAPE-PLD and DAGL are enhanced in these different fibrosis models. In vitro autoradiography further supported that [18F]MAGL-4-11 bound specifically to MAGL in both animal and human fibrotic liver tissues. Our PET ligand [18F]MAGL-4-11 shows excellent sensitivity and specificity for MAGL visualization in vivo and accurately reflects the histological stages of liver fibrosis in preclinical models and human liver tissues.

Preparation and Drug Release in vitro of Danshensu Liposomes / 中国药师

Objective:o prepare Danshensu liposomes and investigate drug release characteristics in vitro. Methods: Danshensu liposomes were prepared by a reverse-phase evaporation method. The encapsulation efficiency was used as the index, an orthogonal test was adopted to investigate the effect of concentration of soybean lecithin, ratio of lipid-Danshensu and pH value of solution on the preparation procedure of Danshensu liposomes. The particle size of the liposomes was also investigated by a transmission electron micro-scope ( TEM) . The concentration of Danshensu was determined by HPLC, and the difference of release characteristics in Danshensu li-posomes and Danshensu solution was measured by a dialysis method. Results:The optimum preparation technology was as follows:the concentration of soybean lecithin was 40 mg·ml-1 ,the ratio of drug-lipid was 1: 10,and the pH value of solution was 6. 6. The mor-phology of the prepared liposomes showed spheric structure with uniform diameter, and the average particle size was ( 174 ± 36 ) nm and the encapsulation efficiency was 38. 9%. The linear range of Danshensu was 2. 0-20. 0 mg·L-1(r=0. 9984). The drug release of liposomes in vitro was slower than that of free Danshensu solution in 24 h. Conclusion:Danshensu liposomes with fine morphology have sustained release property.

Effect of Rehabilitation Gymnastics with Music on Postlaparoscopic Pain Syndrome / 中国康复理论与实践

@#Objective To observe the effect of rehabilitation gymnastics with music on non-incisional pain of gynecological patients after laparoscopic operation.Methods 192 gynecological patients undergone laparoscopic operation were divided into the music group (66 cases, adopted rehabilitation gymnastics matching music after operation), non-music group (64 cases, adopted rehabilitation gymnastics) and routine group (62 cases, adopted routine nursing without rehabilitation gymnastics or music).Results The patients of the music group got pain eased more obviously than those of the non-music group and rule group ( P<0.05).Conclusion The rehabilitation gymnastics with music can relieve non-incisional pain after gynecological laparoscopic operation, and improve anus exhausting.