气相色谱-质谱法测定肝、肾和肉中β_2-受体激动剂残留量

本文用气相色谱-质谱法同时测定肝、肾和肉中β-受体激动剂中1O种βr受体激动剂残留.样品经粉碎、酶水解、沉淀蛋白质、液-液分配后,经SCX柱净化和TMS衍生化后,用美托洛尔(metoprolol)为内标,GC-MS测定.可同时测定11种βr受体激动剂,检出限为0.002mg/kg.……

液相色谱-串联四极杆质谱法对动物源基质中β_2-受体激动剂的检测

A method for the simultaneous determination of β2-agonists residues was developed by LC-MS/MS.The results indicated that the calibration curves showed good linear range from 0.1 g/L to 10 g/L for 11 β2-agonists.The spiked recoveries were between 79% and 110%.The method was rapid,accurate,and was suitable for the determination of β2-agonists in animal food.

Determination of 23 β_2-agonists and 5 β-blockers in animal muscle by high performance liquid chromatography-linear ion trap mass spectrometry

A high performance liquid chromatography-linear ion trap mass spectrometry method using isotope dilution technique has been developed for the simultaneous determination of 23 β2-agonists and 5 β-blockers in animal muscle tissues. Pork and chicken muscle samples were acid hydrolyzed and extracted with 5% trichloracetic acid in water, and then cleaned up using MCX solid phase extraction (SPE) cartridge. Methanol and 0.1% formic acid were used as mobile phases for gradient elution. A Waters AtlantisT3 column was used for separation. ESI positive ion scan mode was used with selective reaction monitoring. 9 β2-Agonists labeled by the deuterium isotope were used as internal standards for quantification. The linear ranges of 23 β2-agonists and 5 β-blockers were 5-200 μg/L, the coefficient of correlation was not less than 0.995, and the limit of detection for each compound in the muscle tissue was below 0.2 μg/kg. The recoveries of each compound in the spiked samples at three levels 5, 10, 20 μg/kg were in the range of 47.3%-123.7%, and the relative standard deviations were in the range of 3.2%-25.7%. The developed method is sensitive and specific for the determination of β2-agonists and β-blockers in pork and chicken muscle samples.

β_2-adrenoceptor in obstructive airway diseases:Agonism, antagonism or both?

Obstructive airway disease is a complex disease entity including several maladies characterized by bronchoconstriction and abnormal airway inflammation. Reversing bronchoconstriction leads to symptomatic relief and improvement in quality of life, both in reversible(bronchial asthma) and partially reversible(chronic obstructive airway disease) obstructive airway diseases. β2-adrenoceptor expressed in human airway is the main β-receptor subtype, and its activation in airway smooth muscle cells leads to bronchodilatation. Drugs targeting β-adrenoceptors have been around for many years, for which agonists of the receptors are used in bronchodilation while antagonists are used in cardiovascular diseases. This review article summarizes the effect and usage of β2-agonist in obstructive airway disease, addressing the benefits and potential risks of β2-agonist. The article also looks at the safety of β-blocker usage for cardiovascular disease in patients with obstructive airway disease. There is also emerging evidence that non-selective β-blockers with inverse agonism ironically can have longterm beneficial effects in obstructive airway disease that is beyond cardiovascular protection. Further trials are urgently needed in this area as it might lead to a dramatic turnaround in clinical practice for obstructive airway diseases as has already been seen in the usage of β-blockers for heart failure.

Fixed-ratio combinations of basal insulin and glucagon-like peptide-1 receptor agonists as a promising strategy for treating diabetes

The maintenance of appropriate glycemic control is important for the prevention of diabetic complications in people with type 2 diabetes(T2D). Numerous oral antidiabetic drugs are now clinically available, but in particular, the introduction of injection regimens using insulin and/or glucagon-like peptide-1 receptor agonist(GLP-1RA)s represents promising step-up options for oral antidiabetic drug treatment. The recently licensed fixed-ratio combination(FRC) products,which comprise basal insulin and a GLP-1RA, have potent anti-hyperglycemic effects and reduce the undesirable side-effects of each component, such as body weight gain, hypoglycemia, and gastrointestinal symptoms. Two FRCs-insulin degludec/Liraglutide and insulin glargine/Lixisenatide-are now clinically available and, to date, several phase Ⅱ/Ⅲ trials have been conducted in particular groups of subjects with T2D. However, their utility in real-world clinical settings is of interest for most clinicians. Recently reported real-world clinical trials of these two FRCs in various situations have demonstrated their efficacy regarding glycemic control and the quality of life of people with T2D. Their long-term safety and efficacy require confirmation, but a treatment strategy that includes an FRC may be compatible with the concept of “well-balanced” therapy in certain groups of patients with T2D who have inadequate glycemic control.

The effect of using long-acting octreotide as adjuvant therapy for patients with grade 2 pancreatic neuroendocrine tumors after radical resection

Objective:To investigate the effect of long-acting octreotide as adjuvant therapy in the prevention of tumor recurrence in patients with grade 2 pancreatic neuroendocrine tumors(pNETs)after radical resection.Methods:The postoperative follow-up data of 130 patients with resectable G2 pNET treated in the Changhai Hospital from 2008 to 2018 were retrospectively analyzed:59 patients received long-acting octreotide as adjuvant therapy for 6 to 12 months(Oct group)and 71 patients received active follow-up(control group),both of which began after the radical resection,with the primary observation endpoint of disease-free survival(DFS)and the secondary study endpoint of overall survival.Results:The median age of the patients in the Oct group and control group was 52 and 54 years,respectively.There were 28 male cases(47.5%)and 33 male cases(46.5%)in the 2 groups.The median maximum tumor diameter was 3.5 and 3.0 cm,respectively;lymph node metastasis was positive in 13 cases(22.0%)and 9 cases(12.7%);there was peripancreatic nerve invasion in 11 cases(18.6%)and 6 cases(8.5%).Survival analysis revealed that there were significant differences in 2-year DFS%(98.3%vs 88.7%,P=.0371)and 3-year DFS%(96.6%vs 85.9%,P=.0498)between the Oct group and control group.Long-acting octreotide treatment was found to reduce the risk of 3-year recurrence of G2 pNET after radical resection(HR=0.2,P=.044)with the application of inverse-probability-of-treatment weighted to balance the limited data bias.Conclusion:Using long-acting octreotide as adjuvant therapy for G2 pNET patients after radical surgery may improve the rate of 3y-DFS,but the benefit needs to be confirmed in a well-designed random control clinical trial.

Voltammetric Method Using Multi-Walled Carbon Nanotubes Modified Glassy Carbon Electrode for the Determination of Terbutaline Sulfate in Pork Sample

Electrochemical properties of terbutaline sulfate (TBS) at the glassy carbon electrode modified with multi-walled carbon nanotubes (MWNTs) were explored by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The response was evaluated with respect to pH, scan rate and other variables. Some electrochemical parameters, such as the charge number and proton number, were calculated. The results indicated that TBS underwent irreversible oxidation at the modified electrode, which was an adsorption-controlled process with two protons and two electrons. The reductive peak current of TBS significantly increased and the peak potential shifted negatively at the modified electrode, thus resulting in an electrode for TBS. The current was proportional to the concentration of TBS over 1.12 and 141 μM with a detection limit of 0.34 μM (at S/N = 3). The modified electrode showed good sensitivity, selectivity and stability for the determination of TBS in pork sample.