十二烷基苯磺酸钠对引发内置物感染表皮葡萄球菌生物被膜的作用

【背景】随着医用内置物的广泛使用,由表皮葡萄球菌生物被膜导致的医院获得性感染不断增多,目前鲜见关于表面活性剂针对表皮葡萄球菌生物被膜作用的报道。【目的】通过研究阴离子型表面活性剂十二烷基苯磺酸钠(sodium dodecyl benzene sulfonate,SDBS)分别对ATCC 35984 (产膜表皮葡萄球菌标准株)生物被膜的清除、生物被膜内细菌代谢和形成生物被膜的关键物质多糖胞间黏附素(polysaccharide intercellular adhesion,PIA)产生的影响,为临床使用SDBS防治由表皮葡萄球菌生物被膜引起的相关感染提供可靠的理论及实践依据。【方法】利用XTT减低法,评价SDBS对ATCC 35984已形成生物被膜的清除效率及对生物被膜内细菌代谢的影响;激光共聚焦显微镜观察SDBS对生物被膜作用的效果;采用刚果红培养基观察SDBS对PIA产生的影响。【结果】浓度为256、128、64、32、16 mg/L的SDBS在作用6、12、24 h时,对ATCC 35984的生物被膜均有显著的清除效率(P0.01);浓度为32 mg/L时对生物被膜内细菌的代谢有显著抑制作用(P0.05),并随作用浓度的增加而增强;激光共聚焦显微镜观察显示256、128、64 mg/L的SDBS对生物被膜的清除效率较为理想,SDBS浓度为64、32 mg/L时对PIA的形成无明显抑制作用。【结论】SDBS对表皮葡萄球菌生物被膜内细菌的代谢有显著抑制作用,对生物被膜形态结构有显著破坏作用。     

阿托伐他汀对慢性硬膜下血肿患者术后MBI、CSS评分的影响

目的:探讨阿托伐他汀对慢性硬膜下血肿(CSDH)患术后改良barthel指数(MBI)和中国卒中量表(CSS)评分的影响。方法:选择2014年2月至2019年2月我院接诊的126例CSDH术后患者进行研究,通过随机数表法将其分为观察组和对照组,每组各63例。两组患者均接受钻孔引流术,对照组术后给予常规处理,观察组联合阿托伐他汀口服治疗,均持续用药1个月。比较两组治疗前后血清神经元特异性烯醇化酶(NSE)、人S100B蛋白(S-100B、肿瘤坏死因子-α(TNF-α)、白介素-1(IL-1)、MBI、CSS评分的变化情况及不良反应的发生情况和复发情况。结果:观察组治疗后血清NSE、S-100B、CRP、TNF-α、IL-1水平均低于对照组(P0.05),MBI评分高于对照组,CSS评分低于对照组(P0.05);两组不良反应发生率比较差异无统计学意义(P0.05),观察组复发率明显低于对照组(P0.05)。结论:阿托伐他汀能降低CSDH患者患术后炎症反应,提高MBI、CSS评分,降低复发率,且不增加不良反应。     

Synthesis of useful fragments in drug discovery: 2-Amino-5-tert-butylpyridine and its oxidised analogues

A novel and robust synthesis of the fragment, 2-amino-5-tert-butylpyridine, has been described, which has been shown to have improved physicochemical properties over 4-tert-butylaniline, when considering drug-like properties. The synthesis also yields fragments containing more highly oxidised precursors to the tert-butyl group as intermediates. These fragments can be incorporated into final target molecules, yielding pharmaceutical compounds and their putative CYP-mediated oxidative metabolites, which can aid in elucidation of metabolic clearance processes.     

The Hyplip2 locus causes hypertriglyceridemia by decreased clearance of triglycerides

The Hyplip2 congenic mouse strain contains part of chromosome 15 from MRL/MpJ on the BALB/cJ background. Hyplip2 mice show increased plasma levels of cholesterol and predominantly triglycerides (TGs) and are susceptible to diet-induced atherosclerosis. This study aimed at elucidation of the mechanism(s) explaining the hypertriglyceridemia. Hypertriglyceridemia can result from increased intestinal or hepatic TG production and/or by decreased LPL-mediated TG clearance. The intestinal TG absorption and chylomicron formation were studied after intravenous injection of Triton WR1339 and an intragastric load of olive oil containing glycerol tri[(3)H]oleate. No difference was found in intestinal TG absorption. Moreover, the hepatic VLDL-TG production rate and VLDL particle production, after injection of Triton WR1339, were also not affected. To investigate the LPL-mediated TG clearance, mice were injected intravenously with glycerol tri[(3)H]oleate-labeled VLDL-like emulsion particles. In Hyplip2 mice, the particles were cleared at a decreased rate (half-life of 25 +/- 6 vs. 11 +/- 2 min; P < 0.05) concomitant with a decreased uptake of emulsion TG-derived (3)H-labeled fatty acids by the liver and white adipose tissue. The increased plasma TG levels in Hyplip2 mice do not result from an enhanced intestinal absorption or increased hepatic VLDL production but are caused by decreased LPL-mediated TG clearance.     

Stochastic Modeling Predictions for the Clearance of Insoluble Particles from the Tracheobronchial Tree of the Human Lung

Bronchial clearance of deposited particles was simulated using a stochastic model of the tracheobronchial tree. The clearance model introduced in this study considers (1) a continuous decrease of the mucus thickness from the trachea to the terminal bronchioles according to a linear or an exponential function, (2) the possibility of mucus discontinuities, which are mainly found in intermediate and distal airways of the tracheobronchial compartment, (3) mucus production in proximal airways, (4) a slow bronchial clearance phase due to the capture of a defined particle fraction f _s in the periciliary sol phase, and (5) an eventual delay of the mucociliary transport at carinal ridges of airway bifurcations. Based on the concept of mucus volume conservation in single bifurcations, a reduction of the thickness of the mucus blanket from proximal to distal airways causes a significant increase of the mucus velocities in small ciliated airways compared to other stochastic modeling predictions assuming a constant thickness of the mucus layer throughout the conducting airways. This effect is further enhanced by the consideration of mucus discontinuities. In contrast, the ability of bronchial airways to produce a certain volume of mucus has a decreasing effect on the mucus velocities. In all generated clearance velocity models, mucociliary clearance is completely terminated within 24 h after exposure, consistent with the experimental evidence. Implementation of a slow bronchial clearance phase predicts a long-term retention fraction, which is fully cleared from the lung after several weeks. For 1-μm MMAD particles, 24-h retention varies between 0.42 and 0.52, in line with the suggestions of the ICRP. Mucus delay at carinal ridges only affects short-term clearance by increasing the retained particle fraction at a given time, while long-term retention is not influenced.     

Selective clearance of glycoforms of a complex glycoprotein pharmaceutical caused by terminal N-acetylglucosamine is similar in humans and cynomolgus monkeys

To understand how the carbohydrate moieties of a recombinant glycoprotein affected its pharmacokinetic (PK) properties, the glycan distribution was directly assessed from serial blood samples taken during PK studies in cynomolgus monkeys and humans. The protein studied was an immunoadhesin (lenercept), containing an Fc domain from human immunoglobulin G (IgG-1) and two copies of the extensively glycosylated extra cellular domain of tumor necrosis factor receptor p55. The protein was recovered in pure form using a dual column, immunoaffinity-reversed-phase high-performance liquid chromatography method. The glycans were released and analyzed by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Alternatively, trypsin was used to obtain glycopeptides, and these were analyzed by MALDI-TOF. The composition versus time profiles show that the distribution of glycans in the Fc domain was not altered over 10 days of circulation, consistent with their sequestration in the interior of the protein. However, the glycan composition in the receptor domain was changed dramatically in the first 24 h and then remained relatively constant. Analysis of the acidic glycans (derived exclusively from the receptor domain) showed that, in the rapid initial phase of clearance, glycans carrying terminal N-acetylglucosamine (tGlcNAc) were selectively cleared from the circulation. This phenomenon occurred similarly in humans and cynomolgus monkeys. Sialic acid content and terminal galactose showed only small changes. These data confirm the correlation of tGlcNAc and half-life of the molecule, and support the hypothesis that the mannose receptor (which can also bind tGlcNAc) causes the variable clearance of this molecule.     

Falls are associated with decreased renal function and insufficient calcitriol production by the kidney

In a double blind placebo controlled 3-year osteoporosis study in elderly women, we collected prospective data on falls. The study population comprised 489 normal elderly women aged 65–77 years randomized to four groups: placebo, calcitriol 0.25 mcg b.i.d., conjugated equine estrogens (0.625 mg/day) and calcitriol + estrogen. Falls occurred in 57% of all women.

Using a Poisson regression model, the placebo group with low GFR-creatinine clearance (CrCl < 60 ml/min) had 60% more falls compared to the group with CrCl ≥ 60 ml/min. Further sub group analyses showed that there is no increased risk of falls with CrCl 60–70, 70–80 and >90 ml/min. Calcitriol treatment significantly reduced the number of falls by 50% (OR = 0.5, 95% CI: 0.4–0.9, p = 0.010) compared to placebo in the low CrCl group.

The group with lower CrCl had lower calcium absorption (p < 0.001), lower serum 1,25-dihydroxyvitamin D (1,25(OH)₂D) (p < 0.001) and normal serum 25OHD suggesting that there is decreased conversion of 25OHD to 1,25(OH)₂D by the aging kidney. It is postulated that the decrease in falls on calcitriol therapy is related to an increase in serum 1,25(OH)₂D, upregulation of VDR and improvement in muscle strength although one cannot exclude an effect on the central nervous system.     

微创颅内血肿清除术对神经细胞损伤因子及血清炎症因子的影响

本研究选取2015年6月至2017年6月我院收治的高血压脑出血患者124例,根据不同的治疗方法分为对照组和观察组。对照组患者采用常规治疗,观察组患者采用常规治疗联合微创颅内血肿清除术治疗,分析微创颅内血肿清除术对脑出血血清铁蛋白(SF)、神经营养因子(NTF)水平以及血清中炎症因子的影响及临床治疗效果。结果表明,治疗前,两组患者出血量、昏迷程度评分比较无统计学差异(p>0.05);治疗后,观察组患者出血量、昏迷程度评分低于对照组(p<0.05)。治疗前,两组患者MMP-9、SF、NTF、GFAP、TNF-α、hs-CRP水平比较无统计学差异(p>0.05);治疗后,观察组患者MMP-9、SF、NTF、GFAP、TNF-α、hs-CRP水平低于对照组(p<0.05)。治疗前,两组患者神经功能评分比较无统计学差异(p>0.05);治疗7 d、14d后,观察组患者神经功能评分低于对照组(p<0.05)。本研究的结果初步说明,微创颅内血肿清除术治疗脑出血可减少患者出血量,降低患者血清炎症因子水平及神经细胞损伤因子的表达水平,改善患者神经功能。     

Suitability of a generic virus safety evaluation for monoclonal antibody investigational new drug applications

Biologics produced from CHO cell lines with endogenous virus DNA can produce retrovirus-like particles in cell culture at high titers, and other adventitious viruses can find their way through raw materials into the process to make a product. Therefore, it is the industry standard to have controls to avoid introduction of viruses into the production process, to test for the presence of viral particles in unclarified cell culture, and to develop purification procedures to ensure that manufacturing processes are robust for viral clearance. Data have been accumulated over the past four decades on unit operations that can inactivate and clear adventitious virus and provide a high degree of assurance for patient safety. During clinical development, biological products are traditionally tested at process set points for viral clearance. However, the widespread implementation of platform production processes to produce highly similar IgG antibodies for many indications makes it possible to leverage historical data and knowledge from representative molecules to allow for better understanding and control of virus safety. More recently, individualized viral clearance studies are becoming the rate-limiting step in getting new antibody molecules to clinic, particularly in Phase 0 and eIND situations. Here, we explore considerations for application of a generic platform virus clearance strategy that can be applied for relevant investigational antibodies within defined operational parameters in order to increase speed to the clinic and reduce validation costs while providing a better understanding and assurance of process virus safety.