中药外源性污染物检测技术的现代研究

中药外源性污染物残留现已成为引起中药不良反应的重要原因之一,按照其来源不同主要包括农/兽药残留、重金属污染、真菌毒素残留、病原微生物污染及其他有机污染物残留。对中药的主要外源性污染物的检查对象及检测方法的现代研究进行综述,为补充、完善、提升中药质量安全体系提供参考和依据。     

百两金皂苷A的微生物转化及其产物的细胞毒活性研究

目的利用燕麦曲霉Aspergillus avenaceus AA 3.4454对百两金皂苷A进行微生物转化,并对转化产物进行细胞毒活性研究。方法将百两金皂苷A放置燕麦曲霉液体培养基中,28℃、160 r/min条件下共培养3 d后,利用多种柱色谱分离转化产物,采用核磁共振等波谱手段鉴定结构;采用MTT法测定转化产物对肿瘤细胞系的细胞毒活性。结果从百两金皂苷A的燕麦曲霉液体发酵液中分离出3个主要转化产物,其结构分别鉴定为西克拉明皂苷元A-3β-O-{α-D-半乳吡喃糖基-(1→4)-[β-D-木吡喃糖基-(1→2)]-β-D-吡喃葡萄糖基-(1→4)-[β-D-吡喃葡萄糖基-(1→2)]-α-L-阿拉伯吡喃糖苷}(1)、西克拉明皂苷元A-3β-O-{α-D-半乳吡喃糖基-(1→4)-β-D-吡喃葡萄糖基-(1→2)-[β-D-木吡喃糖基-(1→2)-β-D-吡喃葡萄糖基-(1→4)]-α-L-阿拉伯吡喃糖苷}(2)、西克拉明皂苷元A-3β-O-{β-D-木吡喃糖基-(1→2)-β-D-吡喃葡萄糖基-(1→4)-[β-D-吡喃葡萄糖基-(1→2)]-[α-D-半乳吡喃糖基-(1→3)]-α-L-阿拉伯吡喃糖苷}(3)。结论首次利用燕麦曲霉对百两金皂苷A进行微生物转化并分离得到在糖链的不同位置增加了α-D型半乳糖的转化产物,3个转化产物均为新化合物,均具有一定的细胞毒活性,且转化产物1对大细胞肺癌细胞的细胞毒活性略优于底物。     

Variable selection for discrete survival model with frailty in presence of left truncation and right censoring: Studying association of environmental toxicants on time-to-pregnancy

Understanding the association between mixtures of environmental toxicants and time-to-pregnancy (TTP) is an important scientific question as sufficient evidence has emerged about the impact of individual toxicants on reproductive health and that individuals are exposed to a whole host of toxicants rather than an individual toxicant. Assessing mixtures of chemical effects on TTP poses significant statistical challenges, namely (i) TTP being a discrete survival outcome, typically subject to left truncation and right censoring, (ii) chemical exposures being strongly correlated, (iii) appropriate transformation to account for some lipid-binding chemicals, (iv) non-linear effects of some chemicals, and (v) high percentage of concentration below the limit of detection (LOD) for some chemicals. We propose a discrete frailty modeling framework (named Discnet) that allows selection of correlated covariates while appropriately addressing the methodological issues mentioned above. Discnet is shown to have better and stable false negative and false positive rates compared to alternative methods in various simulation settings. We did a detailed analysis of the pre-conception endocrine disrupting chemicals and TTP from the LIFE study and found that older females, female exposure to cotinine (smoking), DDT conferred a delay in getting pregnant, which was consistent across various approaches to account for LOD as well as non-linear associations.     

Ureaplasma species and Mycoplasma hominis in cervical fluid of pregnancies complicated by preterm prelabor rupture of membranes

Objective: To evaluate Ureaplasma species and Mycoplasma hominis DNA in the cervical fluid and their association with microbial invasion of the amniotic cavity (MIAC) and/or histological chorioamnionitis (HCA) in pregnancies complicated by preterm prelabor rupture of membranes (PPROM).

Study design: A prospective study of 68 women with singleton pregnancies complicated by PPROM between 24^0/7 and 36^6/7 weeks was conducted. Cervical fluid and amniotic fluid were collected from all women at the time of admission. The Ureaplasma species and Mycoplasma hominis DNA in the cervical fluid were identified using specific real-time PCR.

Results: Ureaplasma species and Mycoplasma hominis DNA were identified in 59% (40/69) of the cervical fluid samples. Women with the presence of Ureaplasma species DNA with and without Mycoplasma hominis DNA in the cervical fluid had a higher rate of MIAC alone [35% (14/40) versus 11% (3/28); p?=?0.02] and a higher rate of the presence of both MIAC and HCA [30% (12/40) versus 4% (1/28); p?=?0.01] than women without Ureaplasma species and Mycoplasma hominis DNA in the cervical fluid.

Conclusions: The presence of Ureaplasma species DNA with and without Mycoplasma hominis DNA in the cervical fluid is associated with a higher risk of MIAC or MIAC and HCA together in pregnancies complicated by PPROM.     

A rapid interleukin-6 bedside test for the identification of intra-amniotic inflammation in preterm labor with intact membranes

Objective: Preterm birth is associated with 5–18% of pregnancies and is the leading cause of neonatal morbidity and mortality. Amniotic fluid (AF) interleukin-6 (IL-6) is a key cytokine for the identification of intra-amniotic inflammation, and patients with an elevated AF IL-6 are at risk for impending preterm delivery. However, results of the conventional method of measurement (enzyme-linked immunosorbent assay; ELISA) are usually not available in time to inform care. The objective of this study was to determine whether a point of care (POC) test or lateral-flow-based immunoassay for measurement of AF IL-6 concentrations can identify patients with intra-amniotic inflammation and/or infection and those destined to deliver spontaneously before term among women with preterm labor and intact membranes.

Methods: One-hundred thirty-six women with singleton pregnancies who presented with symptoms of preterm labor and underwent amniocentesis were included in this study. Amniocentesis was performed at the time of diagnosis of preterm labor. AF Gram stain and AF white blood cell counts were determined. Microbial invasion of the amniotic cavity (MIAC) was defined according to the results of AF culture (aerobic and anaerobic as well as genital mycoplasmas). AF IL-6 concentrations were determined by both lateral flow-based immunoassay and ELISA. The primary outcome was intra-amniotic inflammation, defined as AF ELISA IL-6?≥?2600?pg/ml.

Results: (1) AF IL-6 concentrations determined by a POC test have high sensitivity (93%), specificity (91%) and a positive likelihood ratio of 10 for the identification of intra-amniotic inflammation by using a threshold of 745?pg/ml; (2) the POC test and ELISA for IL-6 perform similarly in the identification of MIAC, acute inflammatory lesions of placenta and patients at risk of impending spontaneous preterm delivery.

Conclusion: A POC AF IL-6 test can identify intra-amniotic inflammation in women who present with preterm labor and intact membranes and those who will subsequently deliver spontaneously before 34 weeks of gestation. Results can be available within 20?min – this has important clinical implications and opens avenues for early diagnosis as well as treatment of intra-amniotic inflammation/infection.     

Umbilical cord prostaglandins in term and preterm parturition

Objective: Prostaglandins (PGs) are considered the universal mediators of parturition. Amniotic fluid PGE₂ and PGF_2α concentrations increase before the onset of spontaneous labor at term, as well as during labor. This study was conducted to determine if the concentrations of umbilical cord PGE₂ and PGF₂α change with advancing gestational age, spontaneous labor at term, and preterm labor (with and without funisitis).

Methods: Umbilical cord (UC) tissue samples were obtained from women (N?=?158) with singleton pregnancies in the following groups: (1) term deliveries without labor (TNL; n?=?20); (2) term deliveries with labor (TIL; n?=?20); (3) spontaneous preterm deliveries (sPTD) with (n?=?20) and without acute funisitis (n?=?20); and (4) preeclampsia without labor (n?=?78). The concentrations of PGs were determined in different locations of the UC. PGE₂ and PGF_2α were measured by specific immunoassays. Non-parametric statistics were used for analysis.

Results: (1) In spontaneous preterm deliveries, the median UC PGE₂ concentration was higher in cases with funisitis than in those without funisitis (233.7?pg/µg versus 87.4?pg/µg of total protein, p?=?0.001); (2) the median UC PGE₂ concentration in sPTD with funisitis was also higher than that obtained from samples who had undergone labor at term (233.7?pg/µg versus 116.1?pg/µg of total protein, p?=?0.03); (3) the UC PGE₂ and PGF_2α concentration increased as a function of advancing gestational age before 36 weeks (PGE₂: ρ?=?0.59, p?<?0.001; PGF_2α: ρ?=?0.39, p?=?0.01), but not after 36 weeks (PGE₂: ρ?=??0.1, p?=?0.5; PGF_2α: ρ?=??0.2, p?=?0.2); (4) the median UC concentrations of PGE₂ and PGF_2α at term was similar in samples obtained from women with and without labor (PGE₂: TNL 133.7?pg/µg versus TIL 116.1?pg/µg of total protein, p?=?0.9; PGF_2α: TNL 8.4?pg/µg versus TIL 8.1?pg/µg of total protein, p?=?0.7); and (5) there was no correlation between UC PG concentration and gestational age at term pregnancy (PGE₂: ρ?=?0.01, p?=?0.9; PGF_2α: ρ?=?0.07, p?=?0.7).

Conclusions: (1) PGE₂ concentrations in the UC are higher in the presence of acute funisitis than in the absence of this lesion; (2) spontaneous labor at term was not associated with a change in the UC concentration of PGE₂ and PGF_2α; and (3) the UC concentrations of PGE₂ and PGF_2α increased as a function of gestational age. We propose that UC PGs act as inflammatory mediators generated in the context of fetal systemic inflammation.     

HIV immunotherapy comes of age: implications for prevention,treatment and cure

Antiretroviral therapy (ART) has reshaped the lives of millions of individuals infected with human immunodeficiency virus (HIV). Patients initiating ART early in the course of infection benefit from a considerable reduction in the risks of acquired immune deficiency syndrome (AIDS) and HIV-related inflammatory events. However, the absence of cure and lifelong requirements of treatment highlight the need of a vaccine and an immunotherapeutic strategy. Like for cancer, a paradigm shift has occurred with the contribution of immune activation and microbial translocation priming aberrant systemic immunity in restricting the ability of the host to mount an effective immune response. The approaches of implementing an effective vaccine to prevent infection and inhibition of immune activation with breakage of viral latency followed by vaccination should lead to an HIV-free generation.     

204株耐碳青霉烯铜绿假单胞菌的临床特点和耐药性分析

摘要： 目的 分析204株耐碳青霉烯铜绿假单胞菌的临床分布、 患者因素和耐药性, 为临床合理有效使用抗菌药物提供科学依据。方法 采取VITEK-2 Compact全自动微生物分析系统对2017年1月—12月我院分离的204株耐碳青霉烯铜绿假单胞菌进行鉴定及药敏试验, 分析临床分布、 标本来源。比较患者不同因素对耐碳青霉烯铜绿假单胞菌检出率的影响。比较呼吸道与非呼吸道分离株、 ICU与普通病房分离株的耐药性差异。结果 204株耐碳青霉烯铜绿假单胞菌分布于ICU 97株、 普通病房107株。标本来源以呼吸道为主, 共169株, 占82.84%; 非呼吸道35株,占17.16%。有基础疾病、 近90 d使用抗菌药物、 进行侵入性操作以及菌株检出时间距入院时间＞48 h的患者耐碳青霉烯铜绿假单胞菌的检出率均分别高于无基础疾病、 近90 d未使用抗菌药物、 未进行侵入性操作以及菌株检出时间距入院时间≤48 h的患者 （P＜0.01）。呼吸道标本组对头孢他啶、 环丙沙星的耐药率显著低于非呼吸道标本组 （P＜ 0.05）, 余12种抗菌药物耐药率差异无统计学意义 （P＞0.05）。普通病房分离株对替卡西林/克拉维酸、 头孢哌酮/舒巴坦、 阿米卡星、 头孢吡肟、 庆大霉素耐药率显著低于ICU病房 （P＜0.05）, 余9种抗菌药物耐药率差异无统计学意义（P＞0.05）。204株耐碳青霉烯铜绿假单胞菌对亚胺培南、 美罗培南耐药率差异无统计学意义 （P＞0.05）。结论 耐碳青霉烯铜绿假单胞菌感染多发生于院内, 在ICU、 普通病房, 呼吸道、 非呼吸道的耐药形势已同样严峻, 应引起临床高度重视。     

1061株血标本分离菌的分布及耐药性

目的了解某院血标本分离菌的分布及耐药状况,为临床诊治血流感染提供实验室依据。方法对该院2015年1月1日—2016年12月31日细菌室血标本分离菌进行鉴定和药敏分析。结果共分离1 061株病原菌,其中革兰阴性菌566株(53.35%),以大肠埃希菌和肺炎克雷伯菌为主;革兰阳性菌383株(36.10%),主要以凝固酶阴性葡萄球菌(CNS)为主;真菌112株(10.55%),以近平滑假丝酵母菌为主。重症监护病房(ICU)是血标本分离菌的主要来源科室,共308株(29.03%),其次为血液内科和小儿内科。大肠埃希菌对亚胺培南耐药率为2.65%,肺炎克雷伯菌对亚胺培南的耐药率为40.12%,产超广谱β-内酰胺酶(ESBLs)的大肠埃希菌和肺炎克雷伯菌分别占62.96%、33.14%。未发现对利奈唑胺和万古霉素耐药的葡萄球菌,耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)、耐甲氧西林金黄色葡萄球菌(MRSA)的检出率分别为83.61%、45.45%。发现对万古霉素和利奈唑胺耐药的屎肠球菌各1株。结论血标本分离病原菌种类多,临床应监测病原菌分布和耐药情况,有效指导临床经验性抗感染治疗。