MTT显色法对成人急性白血病细胞药敏预测性的临床评价

本文报告１２种抗癌剂及２－３种药物联用的体外药敏试验的结果。４８例次ＡＬ的临床疗效与体外药敏符合率６８．８％。在ＡＮＬＬ组，阳性符合率８３．３％。复发病例的符合率７８．６％，阴性队伍率１００％。体外联合药敏与临床疗效的符合率７２．７％，高于单一药，ＭＴＴ药敏试验有助于临床个体化治病的药物选择。     

全自动凝血分析仪检测 ２ 种诱导剂诱导的血小板聚集 试验参考区间的建立

摘要：目的 基于全自动凝血分析仪血小板聚集试验通道，建立表观健康人群血小板最大聚集率（ＭＰＡＲ）的参考区间。方法 募集表观健康人 １３４ 例，采用 Ｓｙｓｍｅｘ ＣＮ３０００ 和 Ｓｙｓｍｅｘ ＣＳ５１００ 全自动凝血分析仪进行不同终浓度二磷酸腺苷（ＡＤＰ）和花 生四烯酸（ＡＡ）诱导的血小板聚集试验检测。根据美国临床和实验室标准协会（ＣＬＳＩ）ＥＰ２８ Ａ３ｃ 文件，按照非参数法计算 ＭＰＡＲ 的参考区间。结果 不同终浓度 ＡＤＰ 和 ＡＡ 诱导的 ＭＰＡＲ 重复性为 ２．０３％ ～ ４．９２％。不同终浓度 ＡＤＰ 和 ＡＡ 诱导的 ＭＰＡＲ 在不同性别和年龄组之间差异均无统计学意义（Ｐ 均＞０．０５）。２ 个检测系统各自 ＡＤＰ 终浓度 ２ 和 ５ μｍｏｌ ／ Ｌ 之间、ＣＳ 系列 ＡＡ 终浓度 ０．５ 和 １．０ ｍｍｏｌ ／ Ｌ 之间 ＭＰＡＲ 差异均有统计学意义（Ｐ 均＜０．０５）。除 ＡＡ 终浓度 １．０ ｍｍｏｌ ／ Ｌ（Ｚ ＝ －２．３１９，Ｐ ＝ ０．０２０），余不同终浓度诱导的 ＭＰＡＲ 在 ２ 个系统间差异均无统计学意义（Ｐ 均＞０．０５）。ＡＤＰ 终浓度 ２、５ 和 １０ μｍｏｌ ／ Ｌ 诱导的 ＭＰＡＲ 生物参考区间在 ＣＮ３０００ 分别为 ４５．４％ ～ ９５．７％、７２．０％ ～ ９４．３％和 ７６．３％ ～ ９５．１％，在 ＣＳ５１００ 分别为 ４５．３％ ～ ９３．７％、 ７３．１％ ～ ９９．１％和 ７５．９％ ～ ９７．６％；ＡＡ 终浓度 ０．５ 和 １．０ ｍｍｏｌ ／ Ｌ 诱导的 ＭＰＡＲ 参考区间在 ＣＮ３０００ 分别为 ７２．１％ ～ ９５．７％和 ８１．０％ ～ ９５．９％，在 ＣＳ５１００ 分别为 ７７．１％ ～ ９６．９％和 ８１．１％ ～ ９９．５％。结论 本研究初步建立了 ＣＮ３０００ 和 ＣＳ５１００ 不同终浓度 ＡＤＰ 和 ＡＡ 诱导的血小板聚集试验 ＭＰＡＲ 参考区间。     

MDM2和p53基因蛋白在急性白血病细胞中表达及与化疗反应的关系

目的：研究人急性白血病（ＡＬ）细胞ＭＤＭ２及ｐ５３基因蛋白表达水平、它们的相互关系及对ＡＬ化疗反应预测的价值。方法：免疫组化方法检测ＭＤＭ２及ｐ５３蛋白。结果：①４６例ＡＬ细胞ＭＤＭ２蛋白阳性率为７１．７％，ｐ５３蛋白阳性率为２１．７％，无细胞类型不同的差别（Ｐ＞０．０５），复发难治组比初发未治组约高１倍；②ＭＤＭ２与ｐ５３蛋白呈反向表达者多见，以ＭＤＭ２（＋），ｐ５３（－）方式表达（６７．４％）高于同向方式表达（１５．２％）（Ｐ＜０．０１）；③ＭＤＭ２蛋白阴性者骨髓缓解（ＢＭＲ）率（６９．２％）高于阳性者（３３３％）（Ｐ＜０．０５），两种蛋白不同表达关系对化疗效应有影响；④ＡＬ患者４例中２例化疗后ＭＤＭ２蛋白转阴性，获ＢＭＲ，另２例则反之。结论：人ＡＬ细胞ＭＤＭ２蛋白阳性率高，ｐ５３蛋白阳性率低；在同一ＡＬ细胞中两者多呈反向表达，且不同表达方式对化疗有影响；在ＡＬ细胞中确实存在ＭＤＭ２（＋），ｐ５３（－）表达方式。ＭＤＭ２蛋白，特别是ＭＤＭ２蛋白与ｐ５３蛋白联检可能预测ＡＬ细胞对化疗的敏感性     

骨髓增生异常综合征降钙素基因甲基化的定量研究

目的：探讨降钙素（ＣＴ）基因高甲基化能否作为骨髓增生异常综合征（ＭＤＳ）向白血病转化的分子标志。方法：采用设有内、外参照的多聚酶链反应（ＰＣＲ），结合限制性内切酶和激光扫描技术，检测２７例ＭＤＳ和６例由ＭＤＳ转化的急性髓细胞白血病（ＡＭＬ）患者骨髓细胞的ＣＴ基因５′端甲基化率（ＣＴＭＲ）。结果：ＭＤＳ患者ＣＴＭＲ为３３．６５％±２３．３７％，显著高于对照组（８．０１％±４．２５％，Ｐ＜０．００１），其中ＲＡＥＢｔ组显著高于对照组和ＲＡ组，已随访３～１０年的ＲＡ患者５例均在正常范围，且无白血病转化。９例ＲＡＥＢｔ的ＣＴＭＲ均＞３０％，随访８例中７例于２个月内转化为ＡＭＬ。结论：ＣＴＭＲ对早期预测ＭＤＳ向白血病转化可能是一个有用的指标。     

广西瑶族与汉族葡萄糖—6—磷酸脱氢酶基因三种常见突变型？…

目的 研究广西瑶族葡萄糖－６－磷酸脱氢酶（Ｇ６ＰＤ）基因突变特点,并与汉族作比较。方法 用突变特异性扩增系统（ＡＲＭＳ）法对广西瑶族３４例和汉族３７例Ｇ６ＰＤ缺乏进行中国常见的三种Ｇ６ＰＤ基因突变型筛查。结果 广西３４例瑶族Ｇ６ＰＤ缺乏的基因型分别为Ｇ１３７６Ｔ １４例（４１．２％）,Ｇ１３８８Ａ９例（２６．５％）,Ａ９５Ｇ５例（１４．７％）,Ｃ１３１１Ｔ１例（２．９％）。     

捕获ELISA法用于肾综合征出血热早期诊断的研究

目的 探讨肾综合征出血热（ＨＦＲＳ）早期诊断方法。方法 用ＭａｃＥＬＩＳＡ、ＩＦＡＴ二种方法同时检测ＨＦＲＳ病人血清４０份;非出血热血清２０份;正常人血清２０份进行对比研究。而且,阳性血清用２－巯基乙醇破坏特异性ＩｇＭ试验,阴性血清加类风湿因子阳性血清干扰试验。结果 用ＭａｃＥＬＩＳＡ法检测ＨＦＲＳ于病程第２日即可出现特异性ＩｇＭ阳性,３～４病日阳性率达８９％;５～７病日阳性率达１００％,而ＩＦＡ     

自体骨髓移植治疗急性白血病73例疗效分析

目的：评价自体骨髓移植（ＡＢＭＴ）治疗急性白血病的疗效。方法：自１９８６年１０月至１９９７年１２月，用ＡＢＭＴ治疗急性白血病７３例，中位年龄２５．５（９～４８）岁。其中急性非淋巴细胞白血病（ＡＮＬＬ）４３例（ＣＲ１３５例，ＣＲ２或早期复发８例），急性淋巴细胞白血病（ＡＬＬ）３０例（ＣＲ１２５例，ＣＲ２或早期复发５例）。预处理方案包括环磷酰胺（ＣＴＸ）１２０ｍｇ／ｋｇ＋单次全身照射（ＳＴＢＩ）９～１０Ｇｙ或马利兰（Ｂｕ）１６ｍｇ／ｋｇ或马法兰（Ｍｅｌ）１６０～１８０ｍｇ／ｍ２＋阿糖胞苷（ＡｒａＣ）４ｇ／ｍ２。结果：所有患者移植后均重建造血，中位随访时间８０６（３２～３４００）天，移植相关死亡７例（９．５％），ＡＮＬＬ、ＡＬＬＣＲ１期移植者３年无病生存率分别为５４９％±７．７％和６７．０％±１０６％，复发率３９．３％±９．３％和２３．７％±１０．６％。结论：为降低白血病复发率和提高患者无病生存率，无骨髓供者的ＣＲ１期急性白血病患者适合接受ＡＢＭＴ。     

孕早期特异性IgM抗体检测Torch感染的实际诊断价值

目的：探讨孕早期检测特异性ＩｇＭ抗体诊断Ｔｏｒｃｈ感染的实际诊断价值。方法：采用ＥＬＩＳＡ法和ＰＣＲ技术对照测定１０２例早孕妇女的特异ＩｇＭ抗体和Ｔｏｒｃｈ病原体。结果：以ＰＣＲ检测阳性作为金标准，弓形体ＩｇＭ的敏感性达１００％，特异性为７２４％，阳性预测值为１２９％，阴性预测值为１００％；风疹病毒ＩｇＭ和ＰＣＲ检测无阳性发现；巨细胞病毒ＩｇＭ的敏感性为９５７％。特异性为４４３％，阳性预测值为３３３％，阴性预测值为９７２％，疱疹病毒的敏感性为８８９％，特异性为５７０％，阳性预测值为１６７％，阴性预测值为９８１％。其中弓形体和巨细胞病毒的敏感性高，但阳性预测值低。结论：ＥＬＩＳＡ法检测Ｔｏｒｃｈ特异性ＩｇＭ抗体作为临床筛查是非常有用和必要的，但仅凭ＩｇＭ抗体阳性尚不能说明孕妇目前是否感染，应对ＩｇＭ抗体阳性者进一步做ＰＣＲ－ＤＮＡ测定。     

质谱快速鉴定联合直接药敏试验在肠杆菌目细菌血流感染诊断中的应用评估

目的 评估质谱快速鉴定联合直接药敏试验在肠杆菌目细菌血流感染诊断中的临床应用价值。 方法 收集 ２０２０ 年 ４ 月—７ 月南京医科大学第一附属医院镜检为革兰阴性杆菌的血培养阳性培养物,采用基质辅助激光解吸电离飞行时间质谱 （ＭＡＬＤＩ?ＴＯＦ ＭＳ）直接鉴定,根据欧洲药敏试验委员会（ ＥＵＣＡＳＴ）发布的阳性血培养液直接快速药敏（ ＲＡＳＴ）指南对大肠埃 希菌和肺炎克雷伯菌进行快速药敏试验和 ４ ｈ、６ ｈ 和 ８ ｈ 药敏结果判读。 将鉴定结果与 Ｖｉｔｅｋ ２ Ｃｏｍｐａｃｔ 全自动微生物鉴定和 药敏系统结果比较。 结果 １２６ 例血培养阳性标本中经常规鉴定后共有肠杆菌目细菌 １０４ 株,质谱快速鉴定检出率为 ９６．２％ （１００ ／ １０４）。 共有 ９０ 株肠杆菌目细菌进行血培养 ＲＡＳＴ,包括肺炎克雷伯菌 ５０ 株和大肠埃希菌 ４０ 株。 肠杆菌目细菌在 ４ ｈ、 ６ ｈ、８ ｈ 时判读的药敏结果与常规药敏试验结果的符合率分别为 ７６．０％（４５３ ／ ５９６）、９２．４％（５５１ ／ ５９６）、９４．０％（５６０ ／ ５９６）;６ ｈ 判 读药敏符合率优于 ４ ｈ（χ２ ＝ １５．５６６,Ｐ＜０．００１）,与 ８ ｈ 差异无统计学意义（χ２ ＝ ０．４９５,Ｐ ＝ ０．４８２）;肺炎克雷伯菌在 ４ ｈ、６ ｈ 和 ８ ｈ 判读的药敏符合率均高于大肠埃希菌（８７．４％ ｖｓ ４８．８％;９５．７％ ｖｓ ８７．８％;９４．６％ ｖｓ ９３．１％）,且在 ４ ｈ 和 ６ ｈ 判读时的差异有统 计学意义（χ２ ＝ １０５．８３９,Ｐ＜０．００１;χ２ ＝ １２．９４７,Ｐ＜０．００１）;耐碳青霉烯类肠杆菌目细菌（ＣＲＥ）在 ４ ｈ、６ ｈ、８ ｈ 的检出率差异无统 计学意义（χ２ ＝ ０．５２８,Ｐ ＝ ０．７６８）,药敏结果符合率差异无统计学意义（χ２ ＝ １．９０８,Ｐ ＝ ０．３８５）。 结论 肠杆菌目细菌血培养阳性 标本质谱快速鉴定准确性高,６ ｈ 可作为肠杆菌目细菌 ＲＡＳＴ 药敏判读的最佳时间点,４ ｈ 即可判断是否存在 ＣＲＥ 感染并推测 其整体抗菌谱。     

用允许性高碳酸血症并机械通气治疗急性呼吸窘迫综合征疗效观察

目的：观察应用允许性高碳酸血症的机械通气方法治疗急性呼吸窘迫综合征（ＡＲＤＳ）的疗效。方法：９例ＡＲＤＳ患者，应用低潮气量（ＶＴ，平均为５．５２ｍｌ／ｋｇ），呼气末正压通气（ＰＥＥＰ）为（０．８６±０．１８）ｋＰａ（１ｋＰａ＝１０．２０ｃｍＨ２Ｏ），ＦｉＯ２为０．５５±０．１７，允许一定限度的呼吸性酸中毒存在（ｐＨ≥７．２０），使动脉血氧分压（ＰａＯ２）维持≥７．３０ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）。结果：９例患者中存活６例（６６．７％），其ｐＨ均值为７．４２±０．０５，ＰａＣＯ２均值为（５．６０±０．５７）ｋＰａ，ＰａＯ２均值为（９．１４±０．６７）ｋＰａ，ＳａＯ２均值为０．９２±０．０３。结论：允许性高碳酸血症的机械通气方法治疗ＡＲＤＳ值得推广。     

急性淋巴细胞性白血病MTT法联合药敏试验对化疗疗效的价值

目的 :探讨急性淋巴细胞性白血病 (ALL)体外联合药敏试验结果与体内化疗疗效的关系。方法 :采用MTT法对 2 4例ALL进行体外药敏。结果 :2 4例患者 ,S/S 10例 ,R/R 10例 ,R/S 4例 ,S/R 0例 ;体外药敏与体内疗效总符合率为 83 .3 % ,阳性符合率为 10 0 % ,阴性符合率为 71.4 % ,灵敏度为 71.4 % ,特异度为 10 0 %。结论 :MTT法敏感性较高 ,特异性强 ,有很好的预示价值 ,同时具有快速、简单 ,经济适用等优点     

Experimental in vitro efficacy study on the interaction of epiroprim plus isoniazid against Mycobacterium tuberculosis

Thirty Mycobacterium tuberculosis strains (8: INH(R)/INH(R), 12: INH(R)/RIF(S), 10: INH(S)/RIF(S)) were examined against MICs of epiroprim (EPM) and isoniazid (INH) separately or in association. EPM alone proved to be insufficiently active against the various mycobacterial isolates (MIC > or =256 microg/ml). The observed average sensitivity to the association of EPM plus INH was, in contrast, considerably increased, as reflected by reduced MICs and lower percentages of resistant strains. MICs ranged between 16 and 32 microg/ml EPM and 2 and 4 microg/ml INH for INH(R) strains. All INH(S) isolates were inhibited by a concentration of 0.125 microg/ml EPM and 0.06 microg/ml INH. The fractional inhibitory concentration indices indicated an additive activity on INH(R)/RIF(R) strains and a synergistic activity on INH(R)/RIF(S) and INH(S)/RIF(S) strains. The synergistic activity of this drug association needs to be confirmed in an animal model.     

Preservation of topoisomerase genetic sequences during in vivo and in vitro development of high-level resistance to ciprofloxacin in isogenic Stenotrophomonas maltophilia strains

OBJECTIVES: To ascertain the participation of topoisomerase mutations in the development of ciprofloxacin resistance in isogenic Stenotrophomonas maltophilia mutants. METHODS: gyrAB and parCE sequences in three paired in vivo isogenic ciprofloxacin-susceptible (MIC range 0.5-4 mg/L) and resistant (16-128 mg/L) S. maltophilia strains (PFGE-characterized) sequentially isolated from three patients, and their corresponding in vitro mutants (ciprofloxacin MIC range 2->128 mg/L), were studied. Efflux phenotype was also investigated. RESULTS: Despite different quinolone susceptibilities, each paired clinical strain displayed identical gyrAB and parCE sequences as well as their corresponding in vitro mutants. Up to 50% (18/36) of in vitro mutants displayed a positive efflux phenotype when nalidixic acid was combined with MC-207,110, while 6% (2/36) showed the phenotype when exposed to nalidixic acid and reserpine. Carbonyl cyanide m-chlorophenylhydrazone or arsenite failed to alter quinolone MICs. CONCLUSIONS: The increase of ciprofloxacin MICs in in vivo and in vitro isogenic S. maltophilia mutant strains was not related to quinolone resistance determining region mutations. Highly effective efflux mechanisms might preserve topoisomerase targets from a ciprofloxacin challenge in S. maltophilia.     

Clinical significance of chemosensitivity in chronic heart failure: influence on neurohormonal derangement, Cheyne-Stokes respiration and arrhythmias

Increased chemosensitivity has been observed in HF (heart failure) and, in order to clarify its pathophysiological and clinical relevance, the aim of the present study was to investigate its impact on neurohormonal balance, breathing pattern, response to exercise and arrhythmic profile. A total of 60 patients with chronic HF [age, 66+/-1 years; LVEF (left ventricular ejection fraction), 31+/-1%; values are means+/-S.E.M.] underwent assessment of HVR (hypoxic ventilatory response) and HCVR (hypercapnic ventilatory response), neurohormonal evaluation, cardiopulmonary test, 24-h ECG monitoring, and assessment of CSR (Cheyne-Stokes respiration) by diurnal and nocturnal polygraphy. A total of 60% of patients had enhanced chemosensitivity. Those with enhanced chemosensitivity to both hypoxia and hypercapnia (i.e. HVR and HCVR), compared with those with normal chemosensitivity, had significantly (all P<0.01) higher noradrenaline (norepinephrine) and BNP (B-type natriuretic peptide) levels, higher prevalence of daytime and night-time CSR, worse NYHA (New York Heart Association) class and ventilatory efficiency [higher VE (minute ventilation)/VCO(2) (carbon dioxide output) slope], and a higher incidence of chronic atrial fibrillation and paroxysmal non-sustained ventricular tachycardia, but no difference in left ventricular volumes or LVEF. A direct correlation was found between HVR or HCVR and noradrenaline (R=0.40 and R=0.37 respectively; P<0.01), BNP (R=0.40, P<0.01), N-terminal pro-BNP (R=0.37 and R=0.41 respectively, P<0.01), apnoea/hypopnoea index (R=0.57 and R=0.59 respectively, P<0.001) and VE/VCO(2) slope (R=0.42 and R=0.50 respectively, P<0.001). Finally, by multivariate analysis, HCVR was shown to be an independent predictor of both daytime and night-time CSR. In conclusion, increased chemosensitivity to hypoxia and hypercapnia, particularly when combined, is associated with neurohormonal impairment, worse ventilatory efficiency, CSR and a higher incidence of arrhythmias, and probably plays a central pathophysiological role in patients with HF.     

In vivo pharmacodynamic efficacy of gatifloxacin against Streptococcus pneumoniae in an experimental model of pneumonia: impact of the low levels of fluoroquinolone resistance on the enrichment of resistant mutants

OBJECTIVES: To investigate the impact of low levels of fluoroquinolone resistance on the emergence of resistant mutants, we examined the mutant selection window (MSW) hypothesis in experimental pneumonia in rabbits infected with pneumococci with various susceptibility levels to fluoroquinolones and treated with gatifloxacin using a human-like regimen (equivalent to 400 mg once daily). The MSW corresponds to the range of concentrations between the minimal inhibitory concentration (MIC) and the mutant prevention concentration (MPC), which is the antibiotic concentration that prevents selection of resistant mutants. MATERIALS AND METHODS: Five pneumococcal strains were tested and were defined as follows [MIC of ciprofloxacin (mg/L)/MIC of gatifloxacin (mg/L)/MPC of gatifloxacin (mg/L)/involved quinolone resistance mechanisms]: strain 16089=0.5/0.25/0.25/wild-type; strain MS1A=2/0.5/1/efflux; strain MS2A=8/1/8/parC S79F; strain MR3B4=10/1/8/parC S79T; strain Gyr-1207=6/4/4/gyrA S81F. RESULTS: A 48 h human-like treatment with gatifloxacin was significantly bactericidal on pneumonia induced by strain 16089 ( > 6 log(10) killing) as well as the efflux derivative strain MS1A ( > 5 log(10) killing). However, a small number of parC-gyrA mutants were recovered in 26% of the animals infected with this efflux strain. As expected, no decrease in viable bacteria counts was observed when pneumonia was induced by the gyrA resistant strain. In contrast, because of the enrichment of highly resistant mutants in 100% of the animals, no significant bacterial reduction was observed after treatment of pneumonia induced by the two susceptible parC mutated strains. A classification and regression tree (CART) analysis identified T(MSW) (percentage of the time during which gatifloxacin serum concentrations are inside the MSW) and AUC(MSW) (area under curve between MIC and MPC values) as the best parameters associated with the enrichment of resistant pneumococci. CONCLUSIONS: This study shows that the acquisition of a low level of fluoroquinolone resistance (especially a parC mutation and to a lesser extent an efflux mechanism) is associated with a clearly lower potential for preventing resistance development. These data support the concept that resistant mutants are selectively enriched when antibiotic concentrations fall inside the mutant selection window and suggest that in vivo dynamic models have to be used to predict the relative abilities of quinolones to prevent mutant selection.     

Pharmacodynamic activity of a cephalosporin, Ro 40-6890, in human skin blister fluid: antibiotic activity in concert with host defense mechanisms.

The pharmacokinetics of an antimicrobial drug in human plasma and in vitro susceptibility testing of an antimicrobial drug do not necessarily predict its efficacy in vivo. Therefore, the combined activity of an antimicrobial drug and blood-derived polymorphonuclear leukocytes (PMN) against Staphylococcus aureus were investigated in vitro. In addition, a pharmacological model allowing analysis of the bactericidal activity of a drug-containing exudate against S. aureus ex vivo was developed. For this purpose, a phagocytic-bactericidal assay was miniaturized to a volume of 100 microliters in order to test the bactericidal activities of an antimicrobial drug with blood PMN in vitro and with skin blister fluid (CBF) ex vivo. Ro 40-6890, the active metabolite of the ester prodrug Ro 41-3399, was used as the test drug. Killing of S. aureus was clearly enhanced when Ro 41-6890 was combined in vitro with a suboptimal number of blood-derived PMN. In eight healthy volunteers, skin blisters were provoked by plasters containing cantharidin. Following a single oral dose of Ro 41-3399, CBF containing PMN was sampled at regular intervals and incubated ex vivo with S. aureus (5 x 10(5) CFU/ml) for 2, 4, 6, and 24 h at 37 degrees C. Concentrations of Ro 40-6890 were measured in CBF (CCBF) and plasma. Ro 40-6890 distributed well from plasma into CBF. When CCBF was below the MIC, an enhanced effect of Ro 40-6890 and host defense factors present in CBF against S. aureus was observed. In conclusion, the present model can provide additional information on human plasma drug concentrations and MICs established in vitro.     

DHFR and DHPS genotypes of Plasmodium falciparum isolates from Gabon correlate with in vitro activity of pyrimethamine and cycloguanil,but not with sulfadoxine-pyrimethamine treatment efficacy

OBJECTIVES: To assess the relationship between the presence of DHFR and DHPS mutations in Plasmodium falciparum, parasite in vitro resistance, and in vivo efficacy of sulfadoxine-pyrimethamine (SP) treatment. PATIENTS AND METHODS: Measurement of SP treatment efficacy in malaria-infected children in Gabon was combined with in vitro tests of susceptibility to pyrimethamine and cycloguanil, and molecular genotyping at several DHFR and DHPS loci of parasites isolated before treatment. DHFR was studied at codons 108, 51, and 59, whereas DHPS gene was typed at positions 436, 437, 540 and 581. RESULTS: SP treatment was effective in 86% of children by day 28. Seventy-five percent of isolates were in vitro resistant to pyrimethamine and 65.5% to cycloguanil. No mutation was detected at codons 540 and 581 of the DHPS gene. Most isolates (71.8%) presented with the triple mutant DHFR genotype, whereas 64.3% combined at least three DHFR and one DHPS mutations. The increase in the number of DHFR mutations was associated with an increase in in vitro resistance to pyrimethamine and cycloguanil; three DHFR mutations conferred pyrimethamine and to a lesser extent cycloguanil resistance. Treatment failures only occurred with isolates presenting at least two DHFR mutations (S108N and C59R) and one DHPS mutation (S436A or A437G), but SP treatment of infections with such parasites gave treatment success in 82.0% of children. CONCLUSIONS: DHFR mutations that lead to high-level in vitro resistance to pyrimethamine plus 1-2 DHPS mutations are not sufficient to induce in vivo failure of SP treatment in young children from Gabon.     

临床呼吸道感染细菌培养检验中涂片镜检技术的病原学诊断价值研究

目的:探讨革兰染色涂片镜检技术在临床微生物室呼吸道感染痰液标本培养检验中病原学诊断价值与临床意义.方法:选取2019年3月～2019年9月送检的临床下呼吸道感染病患者痰液标本,标本前处理后革兰染色涂片,并行接种培养.分析革兰染色涂片检查结果、痰培养结果阳性率与在临床诊断治疗中的有效性.通过SPSS19.0统计学软件应用...     

1704例慢性乙型肝炎患者拉米夫定耐药相关基因突变分析

目的对慢性乙型肝炎(CHB)患者进行拉米夫定(LAM)多位点耐药突变检测。方法提取病毒核酸,对聚合酶链反应扩增产物进行测序,采用DNA STAR(Lasergene)软件分析测序结果。结果共对1 704例CHB患者进行耐药突变检测,检出的主要突变类型为rtM204V/I,约占60.1%,约36.1%的患者合并rtL180M突变,1.3%的患者合并rtV173L突变。结论rtM204V/I是LAM耐药突变的主要类型,可合并rtL180M或rtV173L突变;准确检测各类型耐药突变对临床用药具有重要的指导意义。     

In vitro activities of 5-fluorocytosine against 8,803 clinical isolates of Candida spp.: global assessment of primary resistance using National Committee for Clinical Laboratory Standards susceptibility testing methods

We determined the in vitro activity of flucytosine (5-fluorocytosine [5FC]) against 8,803 clinical isolates of Candida spp. (18 species) obtained from more than 200 medical centers worldwide between 1992 and 2001. The MICs were determined by broth microdilution tests performed according to NCCLS guidelines by using RPMI 1640 as the test medium and the following interpretive breakpoints: susceptible (S), < or =4 micro g/ml; intermediate (I), 8 to 16 micro g/ml; resistant (R), > or =32 micro g/ml. 5FC was very active against the 8,803 Candida isolates (MIC(90), 1 micro g/ml), 95% S. A total of 99 to 100% of C. glabrata (MIC(90), 0.12 micro g/ml), C. parapsilosis (MIC(90), 0.25 micro g/ml), C. dubliniensis (MIC(90), 0.12 micro g/ml), C. guilliermondii (MIC(90), 0.5 micro g/ml), and C. kefyr (MIC(90), 1 micro g/ml) were susceptible to 5FC at the NCCLS breakpoint. C. albicans (MIC(90), 1 micro g/ml; 97% S) and C. tropicalis (MIC(90), 1 micro g/ml; 92% S) were only slightly less susceptible. In contrast, C. krusei was the least susceptible species: 5% S; MIC(90), 32 micro g/ml. Primary resistance to 5FC is very uncommon among Candida spp. (95% S, 2% I, and 3% R), with the exception of C. krusei (5% S, 67% I, and 28% R). The in vitro activity of 5FC, combined with previous data demonstrating a prolonged post-antifungal effect (2.5 to 4 h) and concentration-independent activity (optimized at 4x MIC), suggest that 5FC could be used in lower doses to reduce host toxicity while maintaining antifungal efficacy.