Binding of the veterinary drug tetracycline to bovine hemoglobin and toxicological implications

Tetracycline (TC) is a widely used veterinary drug in animal breeding and fishery. Because of its low bioavailability, the TC residue extensively exists in the environment (e.g. soils, lakes and rivers), which can enter the human body, being potentially harmful. Hemoglobin (Hb) is a protein responsible for oxygen carrying in the vascular system of animals. The aim of this study was to investigate the interaction of bovine hemoglobin (BHb) with TC through spectroscopic and molecular modeling methods. The experimental results revealed that TC can interact with BHb with one binding site to form a TC-BHb complex, mainly through van der Waals interactions and hydrogen bonds. The UV-visible absorption, synchronous fluorescence, and circular dichroism (CD) results revealed that the binding of TC can cause conformational and some microenvironmental changes of BHb, which may affect BHb physiological functions. The synchronous fluorescence experiment disclosed that TC binds into BHb central cavity, which was verified by molecular modeling study. The work contributes to clarify the molecular mechanism of TC toxicity in vivo.     

混凝-氧化法预处理原料药废水

采用混凝-Fenton试剂氧化或混凝-臭氧氧化两种氧化技术预处理上海某医药集团原料药废水。实验结果表明：采用聚合氯化铝（PAC）和聚丙烯酰胺（PAM）复合混凝处理该废水,在混凝pH为9.5、混凝时间1h、PAC和PAM加入量分别为600mg/L和12mg/L时,COD的去除率可达23%;混凝后废水再分别用臭氧氧化和Fenton试剂氧化处理,臭氧氧化明显比Fenton试剂氧化经济有效,在臭氧氧化pH为10、臭氧加入量为15g/L、臭氧氧化时间为1h的条件下,废水COD去除率为27.8%,废水BOD₅/COD明显提高,为后续生化处理提供了良好的条件。     

Determination of chloramphenicol, enrofloxacin and 29 pesticides residues in bovine milk by liquid chromatography-tandem mass spectrometry

A sensitive method for determination of chloramphenicol, enrofloxacin and 29 pesticides residues in bovine milk by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed. Residues of the targets were extracted from milk with acetonitrile, cleaned up by C₁₈-SPE cartridge, and then determined by HPLC-MS/MS. The MS detection was operated in positive or negative ionization mode, depending on the compounds. For confirmation of each target compound, two precursor ion > product ion transitions were selected by multi-reaction monitoring mode (MRM). The method showed good linearity for all the tested compounds over the studied concentration range with correlation coefficient higher than 0.9910. Recoveries for the studied compounds at three spiked levels (0.05, 0.10, 0.19 mg kg⁻¹) in bovine milk were in the range of 71-107% with RSDs not larger than 13.7%, except that recoveries of trifluralin ranged between 62% and 70% at the spiked levels. Limits of quantitation for the analytes were estimated to range between 0.03 × 10⁻³ and 14.5 × 10⁻³ mg kg⁻¹. The proposed method was applied for the determination of the analytes residues in real samples. The found levels of the analytes in milk samples were lower than maximum residues levels (MRL).     

Evaluation of the presence of drugs of abuse in tap waters

A total of seventy samples of drinking water were tested for non-controlled and illicit drugs. Of these, 43 were from Spanish cities, 15 from seven other European countries, three from Japan and nine from seven different Latin American countries. The most frequently detected compounds were caffeine, nicotine, cotinine, cocaine and its metabolite benzoylecgonine, methadone and its metabolite EDDP. The mean concentrations of non-controlled drugs were: for caffeine 50 and 19 ng L⁻¹, in Spanish and worldwide drinking water respectively and for nicotine 13 and 19 ng L⁻¹. Illicit drugs were sparsely present and usually at ultratrace level (<1 ng L⁻¹). For example, cocaine has mean values of 0.4 (Spain) and 0.3 ng L⁻¹ (worldwide), whereas for benzoylecgonine, these mean values were 0.4 and 1.8 ng L⁻¹, respectively. Higher concentrations of benzoylecgonine were found in Latin American samples (up to 15 ng L⁻¹). No opiates were identified in any sample but the presence of methadone and EDDP was frequently detected. Total mean values for EDDP were 0.4 ng L⁻¹ (Spain) and 0.3 ng L⁻¹ (worldwide). Very few samples tested positive for amphetamines, in line with the reactivity of chlorine with these compounds. No cannabinoids, LSD, ketamine, fentanyl and PCP were detected.     

渤海污染现状与治理对策研究

近年来,由于环境污染以及对海洋生物的狂捕滥捞,蓝色海洋面临沦为“死海“和“空海“的危险.实地调查和对实验数据的比较表明:渤海污染呈上升趋势,陆源污染和狂捕滥捞是造成污染的主要原因,其中污染物以无机氮、活性磷酸盐和石油类为主.因此,需要从污染源头和制度上综合治理渤海污染.     

北京市水环境中精神活性物质污染特征

为评价北京市水环境中精神活性物质的污染水平和生态环境风险,利用高效液相色谱-质谱联用法检测了该地区地表水和地下水中6种典型精神活性物质[甲基苯丙胺(METH)、苯丙胺(AMP)、氯胺酮(KET)、麻黄碱(EPH)、甲卡西酮(MC)和羟亚胺(HY)]的质量浓度.结果表明,北京市地表水中共检测出3种目标药物,其质量浓度范围为低于检出限n.d.~70.9ng·L~(-1).EPH的检出频率和质量浓度平均值最高,分别为42%和10.1 ng·L~(-1);其次为METH,检出频率为25%,质量浓度平均值为1.8 ng·L~(-1).地下水样品中只检测到了AMP,检出频率21%,质量浓度水平在n.d.~2.2 ng·L~(-1)之间.与国内外其他研究相比,北京市水环境中精神活性物质的污染浓度总体处于较低水平.METH和EPH浓度最高值均出现在北京市第二大排污河和南城主要污灌渠凉水河.风险评估结果显示,北京市地表水中6种目标药物的风险熵值均小于0.10,表明存在较低的环境风险,但考虑到精神活性物质具有较强的生物活性,它们对水生生态系统的长期和综合风险值得关注.     

X射线衍射法在有机药物研究中的运用

目前随着新药开发、研制过程中对测试方法要求的不断增高,X射线衍射法因其能快速准确地判断药物晶体而被广泛应用于有机药物研究的各个领域.通过对X射线衍射法中装样方法、θ角度和狭缝的选择等参数研究,以获得该方法测定有机药物成分的最佳工作条件,使该法能为有机药物测定提供满意的图谱和更准确的测定结果.     

有机肥中4类典型兽药抗生素的多残留测定

建立了固相萃取-超高效液相色谱-串联质谱（SPE—UPLC—MS／MS）法同时测定有机肥中7种磺胺类、4种氟喹诺酮类、4种四环素类和3种大环内酯类抗生素残留的方法。采用乙腈和磷酸盐缓冲液（pH=3）的混合液作为有机肥样品的提取溶液,用强阴离子交换柱（SAX）-亲水亲脂平衡萃取柱（HLB）串联进行提取液的富集和纯化。以甲醇-φ=0．1％的甲酸溶液作为流动相,进行液相质谱分析。18种抗生素在5—500μg·kg-1的浓度范围内线性关系良好,决定系数（r2）1〉0．99。以3倍信噪比估算磺胺类、氟喹诺酮类、四环素类和大环内酯类的检测限分别为0．37～4．65、0．43—2．42、0．94～2．78和0．83～4．20μg·kg-1,这4类抗生素50和500μg·kg。2个添加水平的样品平均加标回收率分别为71．6％～94．3％、72．3％～86．7％、71．0％～102．2％和70．7％～93．3％,相对标准偏差在2．1％～11．4％之间。采用所建方法对南京地区市售8种有机肥中18种抗生素含量的测定结果显示,除磺胺类外,其他抗生素均有不同程度的检出。     

Fatal motorcycle crashes in wide urban area of Zagreb,Croatia—A 10-year review

Objective: The objective of our study was to determine the prevalence of alcohol and drug intoxication among fatally injured motorcyclists in a wide urban area of Zagreb, Croatia.

Methods: We conducted a single-center observational retrospective study over a 10-year period (2007–2016) in 3 counties covering an area including 1.2 million residents. We reviewed the records on fatally injured motorcyclists, collecting information relating to sex, age, cause of death, time of death in relation to the time of the crash, and the circumstances of the crash (time of day, day of the week, season). Blood alcohol concentration (BAC) and toxicology analysis results were collected and analyzed.

Results: We identified 163 deaths (95.7% males, 4.3% females). Overall, 64.2% of the victims were 20 to 39 years old. The majority (50.9%) of those fatally injured were responsible for causing the traffic crash; the rest were determined not to be responsible or the responsibility could not be determined. The most frequent causes of death were multiple injuries (55.8%) and isolated head trauma (23.3%). The rider’s BAC was above the legal limit for driving (>0.50?g/kg) in 53.8% of cases, with a mean BAC of 1.91?g/kg. There was no difference in riding a motorcycle with a BAC above the legal limit between groups defined as younger (≤39 years of age) and older (≥40 years of age). The number of people with an illegal BAC was significantly higher during weekends than during the work week. The BAC of riders who were responsible for the crash was significantly higher than that of those who were not responsible or whose responsibility could not be determined. Use of illegal drugs or nontherapeutic use of legal drugs was not common and was detected in 10.4% of fatally injured riders.

Conclusions: Alcohol intoxication has a major role in motorcycle crash–related mortality. A significant difference in BAC between fatally injured riders responsible for the accident and those who were not responsible implies that measures directed toward prevention of drinking and driving behavior could lower the number of fatal motorcycle crashes. Weekend measures, especially during spring and summer, could have particularly significant effects.