Rapid multi-class multi-residue method for the confirmation of chloramphenicol and eleven nitroimidazoles in milk and honey by liquid chromatography-tandem mass spectrometry (LC-MS)

A confirmatory method was developed to allow for the analysis of eleven nitroimidazoles and also chloramphenicol in milk and honey samples. These compounds are classified as A6 compounds in Annex IV of Council Regulation 2377/90 (European Commission 1990) and therefore prohibited for use in animal husbandry. Milk samples were extracted by acetonitrile with the addition of NaCl; honey samples were first dissolved in water before a similar extraction. Honey extracts underwent a hexane wash to remove impurities. Both milk and honey extracts were evaporated to dryness and reconstituted in initial mobile phase. These were then injected onto a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system and analysed in less than 9 min. The MS/MS was operated in multiple reaction monitoring (MRM) mode with positive and negative electrospray ionization. The method was validated in accordance with Commission Decision 2002/657/EC and is capable of analysing metronidazole, dimetridazole, ronidazole, ipronidazole and there hydroxy metabolites hydroxymetronidazole, 2-hydroxymethyl-1-methyl-5-nitroimidazole, and hydroxyipronidazole. The method can also analyse for carnidazole, ornidazole, ternidazole, tinidazole, and chloramphenicol. A recommended level of 3 µg l^?1/µg kg^?1 for methods for metronidazole, dimetridazole, and ronidazole has been recommended by the Community Reference Laboratory (CRL) responsible for this substance group, and this method can easily detect all nitroimidazoles at this level. A minimum required performance level of 0.3 µg l^?1/µg kg^?1 is in place for chloramphenicol which the method can also easily detect. For nitroimidazoles, the decision limits (CCα) and detection capabilities (CCβ) ranged from 0.41 to 1.55 µg l^?1 and from 0.70 to 2.64 µg l^?1, respectively, in milk; and from 0.38 to 1.16 µg kg^?1 and from 0.66 to 1.98 µg kg^?1, respectively, in honey. For chloramphenicol, the values are 0.07 and 0.11 µg l^?1 in milk and 0.08 and 0.13 µg kg^?1 in honey. Validation criteria of accuracy, precision, repeatability, and reproducibility along with measurement uncertainty were calculated for all analytes in both matrices.     

风险管理在药品生产监管中的应用

通过分析现阶段药品生产企业风险管理的现状,提出药品监管部门如何更好的利用风险管理。高水平的专家队伍是利用好风险管理的前提;对辖区内药企深入调研是利用好风险管理的基础;对各种检查记录信息的汇总分析是更好利用风险管理的阶梯。     

Illegal treatment of barrows with nandrolone ester: effect on growth,histology and residue levels in urine and hair

The effect of 17β-19-nortestosterone (17βNT) treatment of barrows on residue levels and growth was evaluated. Five barrows were treated three times during the fattening period with 17βNT phenylpropionate (Nandrosol, nandrolone phenylpropionate 50?mg/ml,1?mg/kg body weight). Another five barrows were untreated and five boars (untreated) were kept as positive control. Boars and treated barrows showed a 13 and 9% improvement in growth compared to untreated barrows, with mean final body weights of 121.6, 117.8 and 109.0?kg, respectively. The bulbourethral glands of the treated barrows were three times heavier than untreated barrows. The histology of the prostate and bulbourethral gland of the treated barrows was comparable to the boars, whereas the control barrows showed atrophic glands. Levels of 17βNT ester in hair from treated barrows were high, whereas boars and untreated barrows did not show levels above LLQ. It is concluded that analysis of hair can detect illegal treatment with 17βNT ester in barrows. The size of the bulbourethral gland can also be used for screening in the slaughterhouse.     

Development of an accelerated solvent extraction,ultrasonic derivatisation LC‐MS/MS method for the determination of the marker residues of nitrofurans in freshwater fish

A rapid method using accelerated solvent extraction (ASE) and ultrasound enhanced derivatisation has been developed for the quantitative determination of metabolites of nitrofurans, namely 3‐amino‐2‐oxalidinone (AOZ), 5‐morpholinomethyl‐3‐amino‐2‐oxalidinone (AMOZ), 1‐amino‐hydantoin (AHD) and semicarbazide (SEM), in muscle and skin of carp and finless eel. The target analytes were extracted using ASE, ultrasonic derivatisation for 1?h and then purified by solid phase extraction. Averaged decision limits (CCα) and detection capability (CCβ) of the method were in the range of 0.07–0.13 and 0.31–0.49?µg?kg^?1 in carp and finless eel, respectively. The accuracy in terms of recovery was in the range 77.2–97.4%. The simplified and traditional methods were compared with incurred residue samples. The simplified method reduced the derivatisation time and has been applied to the determination of nitrofurans residues in fish.     

Depletion of metronidazole in brook trout (Salvelinus fontinalis)

Metronidazole (MNZ), which is effective in the treatment of intestinal infections in fish, is also a suspected carcinogen and has been banned in numerous jurisdictions for use in any food-producing animal, including fish. Few reports have been published on the depletion of MNZ in fish. A depletion study was therefore undertaken using MNZ in feed provided to trout under controlled conditions. The water was maintained at 17.5 ± 0.9°C throughout the medication and depletion periods in the study. Following a 20-day acclimatisation period in the holding tanks, the trout (approximately 150–200 g bodyweight at the start of the study) were subjected to two separate medication and withdrawal periods: (A) 5 day medication/5 day withdrawal and (B) 5 day medication/16 day withdrawal. This simulated a potential multiple dosing in an aquaculture setting. In both medication periods, the trout were dosed with medicated feed containing 3 g MNZ kg^–1 fish. Fish were sacrificed in accordance with accepted animal care protocols and tissue samples were analysed by UPLC-MS/MS. Analyte concentrations in trout muscle ranged from a high of 27 000 ± 10 000 ng g^–1 for MNZ and 830 ± 570 ng g^–1 for MNZ-OH on day 1 of withdrawal period A to a low of 1.8 ± 2.3 ng g^–1 for MNZ and < 0.4 ng g^–1 for MNZ-OH on day 16 of withdrawal period B. The results demonstrate that when using the UPLC-MS/MS method, residues of MNZ may be detected in fish treated with MNZ after 16 days of withdrawal.     

羧甲基壳聚糖的生物特性及其在医药领域的应用

羧甲基壳聚糖是壳聚糖经羧甲基化而得的一种水溶性多糖,与壳聚糖相比,羧甲基壳聚糖的水溶性提高,具有比壳聚糖更广泛的应用范围.本文综述了羧甲基壳聚糖的抑菌、抗氧化、止血、抑制肿瘤细胞生长等生理活性,并对其在药物载体、医用材料等医药领域应用的研究进展做一综述.     

Ketoprofen affects the mammary immune response in dairy cows in vivo and in vitro

Nonsteroidal anti-inflammatory drugs are commonly administered parenterally in addition to antimicrobial mastitis therapy to increase the well-being of the diseased animal. As mastitis is usually a localized infection of mammary tissue, we tested the hypothesis that a local administration of nonsteroidal anti-inflammatory drugs through the teat canal could have anti-inflammatory effects on the affected area. We investigated the effects of intramammarily administered ketoprofen (KET) during an LPS-induced immune response on somatic cell count (SCC) and blood–milk barrier integrity. In addition, we investigated the effects of KET on the mRNA abundance of immune factors and their prostaglandin E2 secretion in primary bovine mammary epithelial cells in vitro. Six cows received 0.2 µg of LPS (serotype O26:B6) together with 50 mg of KET into one quarter and LPS only in the opposing quarter. The increase of SCC and of serum albumin (SA) and IgG concentrations and the increase of lactate dehydrogenase (LDH) activity in milk induced by LPS were lower in quarters that received KET in addition. In 3 cows, intramammary KET (50 mg) without additional LPS did not affect SCC, SA, IgG, and LDH in milk. Effects of KET on the immune response of mammary epithelial cells in vitro were investigated in cells from 3 cows challenged with or without LPS (0.2 µg/mL) and with or without additional KET in 2 concentrations (1.25 or 2.5 mg/mL). Ketoprofen reduced the LPS-induced increase of mRNA abundance of tumor necrosis factor α, IL-8, serum amyloid A, and cyclooxygenase-2. The mRNA abundance of cyclooxygenase-1 and prostaglandin E synthase was reduced in cells without LPS challenge by addition of KET at 2.5 mg/mL. Furthermore, the LPS-induced secretion of prostaglandin E2 of mammary epithelial cells into the supernatant could not be detected if KET was added. The results demonstrate that intramammary KET diminishes the increase of SCC and reduces the impairment of the blood–milk barrier (based on SA and LDH in milk), leading to a reduced IgG concentration in milk during LPS-induced mastitis. In mammary epithelial cells, KET limits the expression of several immune factors that are increased during an immune response. In summary, intramammary administration of KET reduces the inflammatory response in the mammary gland. However, it remains unclear whether the inhibited transfer of immune cells and IgG from blood into milk after KET administration would reduce the success of the immune defense in infectious mastitis.     

Distribution of hydrophilic and lipophilic antibacterial drugs in skim milk,cream, and casein

This study determined the distribution of drugs to different milk fractions according to their physicochemical properties. Hydrophilic drugs tend to concentrate in skim milk, whereas lipophilic drugs tend to concentrate in cream. The concentration of a drug in casein is related to its degree of binding to milk proteins. Thus, we aimed to determine whether withdrawal time in whole milk differs from that in cream, casein, and skim milk. Amoxicillin and tylosin were selected as prototype hydrophilic and lipophilic drugs, respectively. The study was conducted in vitro and in vivo to determine whether in vitro conditions reflect the distribution of drugs in the different milk fractions in vivo. The in vivo study was conducted using a crossover design on 6 healthy Holstein dairy cattle. First, amoxicillin (i.m., single dose, 14 mg/kg) was administered to cows. Following a 1-wk washout period, tylosin (i.m., single dose, 15 mg/kg) was administered. Concentrations of amoxicillin and tylosin in milk and milk fractions were measured using HPLC-UV. In the in vitro study, 0.04 to 400 μg/g of amoxicillin and 0.05 to 50 μg/g of tylosin were spiked to drug-free milk and the concentrations in milk and milk fractions were measured. In addition, the percentage of total protein in milk and milk fractions was determined. Amoxicillin accumulated more in skim milk than in cream and casein, both in vitro (92%) and in vivo (73%, skim milk-to-whole milk ratio). The distribution of tylosin in whole and skim milk was similar to that of amoxicillin in the in vitro study, in contrast to the accumulation of tylosin in cream seen in vivo. However, the accumulation ratio of tylosin in cream was lower than expected. By either method, tylosin was less concentrated in casein than in skim milk and cream. The percentage of total protein was similar in skim milk and whole milk and higher than in cream. Thus, amoxicillin accumulates less in cream and casein, suggesting that these fractions would pose a lower risk to the consumer. Tylosin was still present at the maximum residue limit (50 μg/kg) 24 h after injection in the casein fraction and 48 h after injection in the cream fraction.     

Drugs – Do we need them? Applications of non-pharmaceutical therapy in anterior eye disease: A review

Natural products have been in use long before the introduction of modern drug therapies and are still used in various communities worldwide for the treatment of anterior eye disease. The aim of this review is to look at the current non-pharmaceutical modalities that have been tried and assess the body of existing evidence behind them. This includes alternative medicine, existing non-pharmaceutical therapy and more recent low and high tech solutions.A detailed search of all available databases including MEDLINE, Pubmed and Google was made to look for English-language studies for complementary and alternative treatment modalities (CAM), natural therapies and new modalities for anterior eye disease such as blepharitis, dry eye and microbial keratitis. We have included a broad discussion ranging from traditional treatments like honey and aloe vera which have been used for centuries, to the more recent technological advances like Intense Pulsed Light (IPL), LipiFlow and photoactivated chromophore for corneal cross linking in infectious keratitis (PACK-CXL).Alternative management strategies may have a role in anterior eye diseases and have a potential in changing the way we currently approach them. Some of the available CAM could play a role if incorporated in to current management practices of not only chronic diseases like blepharitis and dry eye, but also acute conditions with significant morbidity like microbial keratitis. Further large-scale randomized control trials stratified by disease severity are required to improve our understanding and to evaluate the use of non-pharmaceutical therapy against current practice.     

口服铁剂类药物联合饮食疗法治疗孕产妇贫血的临床价值研究

目的：探讨口服铁剂类药物联合饮食疗法治疗孕产妇贫血的临床价值,以供参考。方法：将牡丹江医学院2011年5月—2013年4月收治的贫血孕产妇105例纳入本研究,随机分组。对照组孕产妇给予口服铁剂类药物治疗,实验组孕产妇给予口服铁剂类药物联合饮食疗法治疗。观察两组孕产妇在治疗前后血红蛋白（Hb）、红细胞计数（RBC）、平均血红蛋白浓度（McHc）、血清铁（SI）、转铁蛋白饱和度（TS）等指标的变化和妊娠结局的差异性。结果：与治疗前对比,治疗后孕产妇Hb、RBC、McHc、SI、TS等指标均有一定程度的上升,其中实验组各指标上升幅度明显大于对照组,组间差异经统计学分析后认为有意义（P〈0.05）。与对照组对比,实验组不良妊娠结局发生率明显较低,组间差异统计学分析后认为有意义（P〈0.05）。结论：口服铁剂类药物联合饮食疗法治疗孕产妇贫血可有效改善贫血症状,对妊娠结局具有积极的影响。