Carboxylesterase catalyzed 18O-labeling of carboxylic acid and its potential application in LC-MS/MS based quantification of drug metabolites

LC-MS quantification of drug metabolites is sometimes impeded by the availability of internal standards that often requires customized synthesis and/or extensive purification. Although isotopically labeled internal standards are considered ideal for LC-MS/MS based quantification, de novo synthesis using costly isotope-enriched starting materials makes it impractical for early stage of drug discovery. Therefore, quick access to these isotope-enriched compounds without chemical derivatization and purification will greatly facilitate LC-MS/MS based quantification. Herein, we report a novel ¹⁸O-labeling technique using metabolizing enzyme carboxylesterase (CES) and its potential application in metabolites quantification study. Substrates of CES typically undergo a two-step oxygen exchange with H₂¹⁸O in the presence of the enzyme, generating singly- and doubly-¹⁸O-labeled carboxylic acids; however, unexpected hydrolytic behavior was observed for three of the test compounds – indomethacin, piperacillin and clopidogrel. These unusual observations led to the discovery of several novel hydrolytic mechanisms. Finally, when used as internal standard for LC-MS/MS based quantification, these in situ labeled compounds generated accurate quantitation comparable to the conventional standard curve method. The preliminary results suggest that this method has potential to eliminate laborious chemical synthesis of isotope-labeled internal standards for carboxylic acid-containing compounds, and can be developed to facilitate quantitative analysis in early-stage drug discovery.     

Inactivated influenza vaccine formulated with single-stranded RNA-based adjuvant confers mucosal immunity and cross-protection against influenza virus infection

Influenza vaccination is considered the most valuable means to prevent and control seasonal influenza infections, which causes various clinical symptoms, ranging from mild cough and fever to even death. Among various influenza vaccine types, the inactivated subunit type is known to provide improved safety with reduced reactogenicity. However, there are some drawbacks associated with inactivated subunit type vaccines, with the main ones being its low immunogenicity and the induction of Th2-biased immune responses. In this study, we investigated the role of a single-stranded RNA (ssRNA) derived from the intergenic region in the internal ribosome entry site of the Cricket paralysis virus as an adjuvant rather than the universal vaccine for a seasonal inactivated subunit influenza vaccine. The ssRNA adjuvant stimulated not only well-balanced cellular (indicated by IgG2a, IFN-γ, IL-2, and TNF-α) and humoral (indicated by IgG1 and IL-4) immune responses but also a mucosal immune response (indicated by IgA), a key protector against respiratory virus infections. It also increases the HI titer, the surrogate marker of influenza vaccine efficacy. Furthermore, ssRNA adjuvant confers cross-protective immune responses against heterologous influenza virus infection while promoting enhanced viral clearance. Moreover, ssRNA adjuvant increases the number of memory CD4⁺ and CD8⁺ T cells, which can be expected to induce long-term immune responses. Therefore, this ssRNA-adjuvanted seasonal inactivated subunit influenza vaccine might be the best influenza vaccine generating robust humoral and cellular immune responses and conferring cross-protective and long-term immunity.     

Acute total hip arthroplasty for older patients with acetabular fractures: A meta-analysis

ObjectiveMultiple treatment options for acetabular fractures in geriatric patients exist. However, no large-scale studies have reported the outcomes of acute total hip arthroplasty (THA) in this patient population. We systematically evaluated all available evidence to characterize clinical outcomes, complications, and revisions of acute THA for acetabular fractures in geriatric patients.MethodsMeta-analysis of 21 studies of 430 acetabular fractures with mean follow-up of 44 months (range, 17−97 months). Two independent researchers searched and evaluated the databases of Ovid, Embase, and United States National Library of Medicine using a Boolean search string up to December 2019. Population demographics and complications, including presence of heterotopic ossification (HO), dislocation, infection, revision rate, neurological deficits, and venous thromboembolic event (VTE), were recorded and analyzed.ResultsWeighted mean Harris Hip Score was 83.3 points, and 20% of the patients had reported complications. The most common complication was HO, with a rate of 19.5%. Brooker grade III and IV HO rates were lower at 6.8%. Hip dislocation occurred at a rate of 6.1%, 4.1% of patients developed VTE, deep infection occurred in 3.8%, and neurological complications occurred in 1.9%. Although the revision rate was described in most studies, we were unable to perform a survival analysis because the time to each revision was described in only a few studies. The revision rate was 4.3%.ConclusionsAcute THA is a viable option for treatment of acetabular fracture and can result in acceptable clinical outcomes and survivorship rates in older patients but with an associated complication rate of approximately 20%. Considering the limited treatment options, THA might be a viable alternative for appropriately selected patients.     

糖尿病肾病内热证与肾功能及炎症因子的相关性研究

目的:观察糖尿病肾病不同分期内热证与肾功能及炎症指标的相关性。方法:收集202例糖尿病肾病患者的临床资料,采用酶联免疫吸附法检测微炎症指标,包括超敏C反应蛋白(high-sensitivity C-reactive protein,HS-CRP)、白细胞介素-6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α),进行统计分析。结果:与非内热证组比较,中期、晚期内热证组24小时尿蛋白定量明显升高;晚期内热证组的血清肌酐明显升高,肾小球滤过率(glomerular filtration rate,GFR)明显降低;炎症因子CRP、IL-6、TNF-α随疾病进展均呈上升趋势;晚期内热证组与非内热证组比较,IL-6、TNF-α升高;中期HS-CRP与内热积分呈正相关,晚期TNF-α与内热积分呈正相关。结论:内热病机贯穿于糖尿病肾病的始终,与糖尿病肾病肾功能以及疾病进展密切相关;同时,内热积分与炎症因子HS-CRP、TNF-α的表达存在一定的相关性,这种相关性在疾病中期、晚期表现更加明显。     

浮肩损伤的临床特征和治疗

目的 总结浮肩损伤（floating shoulder injury，FSI）的临床特征和治疗效果。方法1993年1月-2004年9月收治浮肩损伤患者8例，除2例行锁骨固定带固定外，其余6例均行手术治疗，其中单纯行锁骨切开复位重建钢板内固定1例，同时行肩胛骨内固定5例。受伤至手术时间为2h～7d，平均3．5d，术后6个月对患肩功能进行Constant评分判定疗效，并对浮肩损伤的临床特征和治疗进行总结。结果6例患者经过6个月～3年（平均11个月）的随访，锁骨和肩胛骨骨折均愈合，肩关节活动范围无明显受限，但有2例患者在举重物时肩关节有轻度的疼痛，1例患侧上肢肌力较对侧稍减弱。术后6个月患肩功能Constant评分平均为93分。结论浮肩损伤多为高能量暴力所致的不稳定性肩胛带损伤，在治疗方案上尚存争议。但对移位明显的浮肩损伤以及有伴发伤的浮肩损伤进行手术治疗是必要的。     

后路椎弓根螺钉内固定结合椎体成形治疗胸腰椎骨折

目的探讨应用椎弓根螺钉内固定加自固化磷酸钙人工骨(CPC)椎体成形治疗胸腰椎骨折的临床效果。方法对38例新鲜胸腰椎骨折行椎弓根螺钉系统固定的同时,加CPC行椎体成形。结果33例获随访5~29个月,无内固定松动及断裂,伤椎高度及脊柱生理弧度无丢失。3例发生CPC渗漏至椎管和椎间孔内,椎管内静脉丛漏2例,椎前静脉漏1例。结论椎弓根螺钉内固定加CPC椎体成形是治疗新鲜胸腰椎骨折的一种可行方法。     

经关节入路微创钢板固定技术治疗股骨远端C型骨折

目的探讨经关节入路微创钢板固定(MIPPO)技术治疗股骨远端C型骨折的临床疗效。方法2002年4月～2005年2月,应用MIPPO技术治疗股骨远端C型骨折14例,按AO/ASIF分类：C1型3例,C2型6例,C3型5例。先行关节内骨折切开复位、松质骨螺钉固定,再行髁上部分骨折间接复位、经关节内切口插入髁支撑钢板或LISS钢板桥接固定骨折。结果12例患者获得10～32个月(平均18．4个月)随访,骨折均获愈合,愈合时间10周～12个月,平均4．6个月。按Kolmert和Wulff的评价标准：优4例,良5例,可2例,差1例,优良率为75%。结论应用MIPPO技术治疗股骨远端C型骨折实现了微创操作,具有创伤小、软组织干扰少、骨折愈合快等优点,疗效满意。     

AO钢板内固定治疗跟骨骨折

目的 探讨复杂跟骨骨折治疗方法及AO钢板内固定价值.方法 应用AO钢板治疗累及距下关节的跟骨骨折24例,术中注意关节面复位和Bohler角的恢复.结果 24例病人经12～24个月随访,按照Fernandez评定标准:24例跟骨SandersⅡ-Ⅳ型骨折病人有18足评为优良.结论 距下关节面的复位和Bohler角的恢复,牢固的内固定和术后足够长时间的负重限制是成功的关键.     

空心螺钉治疗股骨颈骨折术后并发症的分析

目的探讨影响空心螺钉治疗股骨颈骨折术后早期并发症及中晚期股骨头缺血性坏死的因素。方法对1994年1月～2004年1月间应用空心螺钉治疗的116例股骨颈骨折患者进行回顾性总结,将患者性别、年龄、骨折类型、骨折复位情况、外伤至手术时间与骨折术后早期并发症及中晚期股骨头缺血性坏死间的关系进行统计学分析。结果116例患者获平均(3．2±2．5)年(1～11年)随访。术后早期并发症包括：骨折内固定失败6例,骨折周围再骨折2例,感染2例,下肢深静脉血栓6例。年龄是引起骨折术后早期并发症的主要因素之一；骨折术后早期并发症还与骨质情况及内固定技术有关。本组16例出现股骨头缺血性坏死,其坏死率为13．8%。造成股骨头缺血性坏死的因素主要是骨折类型,其次为骨折复位情况。结论①年龄大于60岁的患者股骨颈骨折术后早期并发症相对多。②对于骨折移位严重的高龄患者,建议行人工关节置换术。③内固定术应尽可能解剖复位、坚强牢靠,以减少术后股骨头缺血性坏死的发生。