Role of site-directed mutagenesis and adjuvants in the stability and potency of anthrax protective antigen

Anthrax is a zoonotic infection caused by the gram-positive, aerobic, spore-forming bacterium Bacillus anthracis. Depending on the origin of the infection, serious health problems or mortality is possible. The virulence of B. anthracis is reliant on three pathogenic factors, which are secreted upon infection: protective antigen (PA), lethal factor (LF), and edema factor (EF). Systemic illness results from LF and EF entering cells through the formation of a complex with the heptameric form of PA, bound to the membrane of infected cells through its receptor. The currently available anthrax vaccines have multiple drawbacks, and recombinant PA is considered a promising second-generation vaccine candidate. However, the inherent chemical instability of PA through Asn deamidation at multiple sites prevents its use after long-term storage owing to loss of potency. Moreover, there is a distinct possibility of B. anthracis being used as a bioweapon; thus, the developed vaccine should remain efficacious and stable over the long-term. Second-generation anthrax vaccines with appropriate adjuvant formulations for enhanced immunogenicity and safety are desired. In this article, using protein engineering approaches, we have reviewed the stabilization of anthrax vaccine candidates that are currently licensed or under preclinical and clinical trials. We have also proposed a formulation to enhance recombinant PA vaccine potency via adjuvant formulation.     

Rociletinib (CO-1686) enhanced the efficacy of chemotherapeutic agents in ABCG2-overexpressing cancer cells in vitro and in vivo

Overexpression of adenosine triphosphate (ATP)-binding cassette subfamily G member 2 (ABCG2) in cancer cells is known to cause multidrug resistance (MDR), which severely limits the clinical efficacy of chemotherapy. Currently, there is no FDA-approved MDR modulator for clinical use. In this study, rociletinib (CO-1686), a mutant-selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), was found to significantly improve the efficacy of ABCG2 substrate chemotherapeutic agents in the transporter-overexpressing cancer cells in vitro and in MDR tumor xenografts in nude mice, without incurring additional toxicity. Mechanistic studies revealed that in ABCG2-overexpressing cancer cells, rociletinib inhibited ABCG2-mediated drug efflux and increased intracellular accumulation of ABCG2 probe substrates. Moreover, rociletinib, inhibited the ATPase activity, and competed with [¹²⁵I] iodoarylazidoprazosin (IAAP) photolabeling of ABCG2. However, ABCG2 expression at mRNA and protein levels was not altered in the ABCG2-overexpressing cells after treatment with rociletinib. In addition, rociletinib did not inhibit EGFR downstream signaling and phosphorylation of protein kinase B (AKT) and extracellular signal-regulated kinase (ERK). Our results collectively showed that rociletinib reversed ABCG2-mediated MDR by inhibiting ABCG2 efflux function, thus increasing the cellular accumulation of the transporter substrate anticancer drugs. The findings advocated the combination use of rociletinib and other chemotherapeutic drugs in cancer patients with ABCG2-overexpressing MDR tumors.     

PBL结合绘图教学模式在胰腺癌患者肝素钠皮下注射临床教学中的作用

[摘要]目的探讨问题导向学习(PBL)结合绘图教学模式在临床护理带教中的应用效果。方法纳入2016年6月~2017年6月在我院实习的本科护生78名,按等比例随机分为观察组和対照组,观察组采取PBL结合绘图学模式法,对照组采用单纯PBL教学模式,利用统计学方法按照参考指标对两组实习生的考核数据进行对比分。结果观察组理论知识得分明显大于对照组[(90.31±4.55)分vs.(81.30±5.69)分],观察组临床实践技能得分明显大于对照组[(92.21±4.18)分vs.(80.31±5.39)分],差异均有统计学意义(P0.05)。结论PBL结合绘图教学模式临床护理带教中效果显著,比单纯PBL教学模式更具有优势,更有利于培养学生的循证思维与创新能力,提高临护理教学质量,在临床护理带教中值得推广。     

Randomized Crossover Trial of Phosphate-binding Medication on Serum Phosphate Levels in Patients With Aortic Stenosis

PurposeAortic stenosis is a common cause of valvular heart disease with no means of prevention. The recognized association between aortic stenosis and serum phosphate raises the possibility of preventing progression of the disorder by using phosphate-binding drugs, but there is uncertainty whether such treatment lowers serum phosphate levels in patients without diagnosed renal failure. This pilot study was conducted to answer this question in patients with aortic stenosis.MethodsA randomized, double-blind, crossover trial of the phosphate-binding drug sevelamer was conducted in 72 patients. Patients were prescribed sevelamer 0.8 g (low-dose), sevelamer 2.4 g (high-dose), and matching placebo, 3 times daily with food; each regimen lasted 6 weeks and was allocated at random. Serum phosphate levels were measured at the end of each treatment period, and within-person levels were compared.FindingsSixty-one patients completed the 3 treatment periods. There was no significant difference in the mean end-treatment phosphate levels across all patients (3.38, 3.36, and 3.31 mg/dL with placebo, low-dose sevelamer, and high-dose sevelamer, respectively). Post hoc analysis showed a reduction in phosphate levels with increasing sevelamer dose in the highest baseline phosphate quartile group; a 0.3 mg/dL reduction (mean, 4.09 mg/dL with placebo, 3.95 mg/dL with low-dose sevelamer, and 3.79 mg/dL with high-dose sevelamer; P_trend = 0.027).ImplicationsSevelamer had no overall statistically significant effect in lowering serum phosphate levels, but a reduction was observed in patients with phosphate levels in the highest quartile group of the population distribution. This hypothesis-generating result requires confirmation in an independent study. If confirmed, a trial of sevelamer in preventing the progression of aortic stenosis may be justified in patients with high phosphate levels. ISRCTN Registry identifier: ISRCTN17365679.     

Four cases of sodium nitrite suicidal ingestion: A new trend and a relevant Forensic Pathology and Toxicology challenge

Sodium nitrite (NaNO₂) is an inorganic compound commonly used as a food additive, antifreeze admixture, and fertilizer. Its toxicity mechanism is mainly represented by the oxidation of ferrous iron to ferric iron of one of the four heme structures in haemoglobin with the onset of methaemoglobin. The mechanism of death by sodium nitrite toxicity is severe hypoxia. We present four cases of suicidal sodium nitrite ingestion that closely occurred within a two months-period. Self-poisoning with sodium nitrite actually represents an increasing trend in nitrates’ related deaths. In order to reach a precise diagnosis of NaNO₂ intoxication, a complete toxicological analysis should be carried out including not only MetHb blood levels but also nitrites and nitrites in standard or alternative matrices as a routine procedure. Autopsy should be carefully performed to detect common indicators of hypoxia or more rarely evident typical by themselves-non specific signs of sodium nitrite toxicity. Suicidal manner of death should be carefully considered when circumstantial data support that ingestion of large amounts of NaNO₂ occurred as a consequence of a self-injurious behaviour. Relevant informations include victim’s previous Internet or book researches about paths to follow to commit suicide with sodium nitrate, employment and past medical history, with strong regard to psychiatric diseases as well as eventual taking psycotropic drugs.Finally, an accurate integration of autoptic and toxicological results with circumstantial data is necessary to make correct diagnosis of death due to acute respiratory failure secondary to suicidal sodium nitrite ingestion.     

关节镜清理术联合透明质酸钠治疗膝骨性关节炎的效果

目的探讨关节镜清理术联合透明质酸钠治疗膝骨性关节炎患者的效果。方法100例膝骨性关节炎患者随机分为两组各50例,对照组采用关节镜清理术治疗,实验组采用关节镜清理术联合透明质酸钠治疗,比较两组的关节液炎性因子水平、膝关节功能以及疼痛情况。结果治疗后,实验组的TNF-α、IL-6、IL-8水平均显著低于对照组(P<0.05)。治疗1个月、3个月、6个月后,实验组的Lysholm评分均显著高于对照组,VAS评分均显著低于对照组(P<0.05)。结论关节镜清理术联合透明质酸钠治疗膝骨性关节炎可降低患者关节液炎性因子水平,改善膝关节功能,减轻疼痛。     

Faster bone union progression and less sclerosis at the osteotomy margin after medial opening-wedge high tibial osteotomy using highly porous β-tricalcium phosphate granules versus allogeneic bone chips: A matched case–control study

BackgroundThis study compared bone union progression using highly porous (80% porosity) β-tricalcium phosphate (β-TCP) granules or allogeneic bone chips in the gap created by medial opening-wedge high tibial osteotomy (MOWHTO).MethodsThe study population consisted of 54 patients who received MOWHTO with locking plate fixation: 27 patients using highly porous β-TCP granules, and 27 age- and sex-matched patients using allogeneic bone chips. Bone union progression was evaluated 1, 3, 6, and 12 months postoperatively. The presence of radiographic sclerosis at the osteotomy margin was also assessed.ResultsAmong all patients, the highest degree of bone union observed 12 months postoperatively was grade 4. As postoperative time passed, bone union progression of highly porous β-TCP granules increased linearly and was statistically significant compared with that of cancellous allogeneic bone chips (P = 0.014). The presence of radiographic sclerosis at the osteotomy margin was significantly less common in the β-TCP group than in the allograft group (P = 0.003) and was the strongest predictor of delayed progress of bone union (odds ratio = 6.16, P = 0.006).ConclusionsPatients who underwent MOWHTO using highly porous β-TCP granules had faster new bone remodeling, less radiographic sclerosis at the osteotomy margin, and no inferior clinical outcome compared with allogeneic bone chips, as determined at the 1-year follow up. The presence of radiographic sclerosis at the osteotomy margin in patients undergoing MOWHTO using allogeneic bone or synthetic bone substitute may indicate delayed progress of bone union.     

玻璃酸钠注射结合乙哌立松治疗膝骨关节炎的效果观察

目的 探讨玻璃酸钠注射结合乙哌立松治疗膝骨关节炎的临床效果。方法 94例膝骨关节炎患者,按照随机数字法将其分为对照组与实验组,每组47例。对照组患者使用玻璃酸钠进行治疗,实验组患者使用玻璃酸钠注射结合乙哌立松进行治疗。比较两组患者治疗前后尿液中CTX-Ⅱ含量、疼痛评分、膝关节功能评分、生活质量评分。结果 治疗后,实验组尿液中CTX-Ⅱ含量(236.78±26.59)ng/mmol低于对照组的(364.45±41.23)ng/mmol,差异具有统计学意义(P<0.05)。实验组疼痛评分(3.01±0.89)分低于对照组的(4.46±1.68)分,差异具有统计学意义(P<0.05)。实验组膝关节功能评分(84.45±11.68)分高于对照组的(75.89±11.84)分,差异具有统计学意义(P<0.05)。实验组物质生活、社会角色、心理健康、躯体健康评分分别为(86.23±1.89)、(87.43±2.13)、(87.52±3.01)、(88.23±4.13)分,均高于对照组的(76.02±4.31)、(79.23±4.56)、(79.01±4.89)、(77.25±4.89)分,差异具有统计学意义(P<0.05)。结论 玻璃酸钠注射结合乙哌立松治疗膝骨关节炎的临床效果显著。