电视纵隔镜与CT在胸部疾病诊断的临床应用

目的 探讨电视纵隔镜检查与CT在纵隔疾病的诊断及术前肺癌N分期上的价值,并比较两种诊断方法之间的差别.方法 回顾性分析临床行CT或PET-CT检查后诊断为纵隔疾病及高度怀疑为肺癌的患者68例的电视纵隔镜检查.纵隔疾病组的电视纵隔镜检查诊断与CT诊断相比较,判断术前术后的诊断符合率及CT的误诊率;以肺癌组行电视纵隔镜检查后病理报告为"金标准"推测电视纵隔镜及CT对肺癌纵隔淋巴结转移诊断的灵敏度、特异度、真实性、阳性预测值及阴性预测值,并比较电视纵隔镜与CT在肺癌纵隔淋巴结转移的诊断上有无差异性.结果 ①纵隔疾病组中电视纵隔镜检查术前术后的诊断符合率是55%(11/20),CT的误诊率是45%(9/20).术前诊断为肺癌的病例组中,以41例病理报告确诊为肺癌的病例为样本推测电视纵隔镜检查对肺癌伴有纵隔淋巴结转移诊断的灵敏度93.3%,特异度100%,真实性97.6%,阳性预测值100%,阴性预测值96.3%;CT对肺癌伴有纵隔淋巴结转移诊断的灵敏度66.7%,特异度53.8%,真实性58.5%,阳性预测值45.5%,阴性预测值73.7%,电视纵隔镜检查的各项指标均高于CT,P<0.05(X<,C><'2>=4.083),差异有显著性.②本研究组的手术并发症发生率2.94%(2/68),其中,1例为气胸,1例为喉返神经损伤.结论 电视纵隔镜检查对纵隔疾病诊断及对术前肺癌N分期准确性高,优于CT;电视纵隔镜检查安全有效,在胸外科领域的发展前景广阔.     

术前超声检查评估甲状腺微小乳头状癌颈部淋巴结转移的临床价值

目的探讨术前超声检查评估甲状腺微小乳头状癌颈部淋巴结转移的临床价值。方法回顾性分析2009年1月至2012年7月在上海交通大学医学院附属瑞金医院行超声检查并进行甲状腺手术的315例甲状腺微小乳头状癌患者。以术后石蜡切片病理检查结果作为金标准,计算术前超声评估颈部淋巴结有无转移、中央组淋巴结有无转移、颈侧组淋巴结有无转移的敏感度、特异度、阳性预测值及阴性预测值。结果共308例患者行淋巴结清扫,7例患者未行淋巴结清扫。术前超声检查评估颈部淋巴结有无转移的敏感度为38.8%（50/129）,特异度为96.1%（172/179）,阳性预测值为87.7%（50/57）,阴性预测值为68.5%（172/251）;术前超声检查评估中央组淋巴结有无转移的敏感度为31.4%（38/121）,特异度为96.7%（181/187）,阳性预测值为86.4%（38/44）,阴性预测值为68.5%（181/264）;术前超声检查评估颈侧组淋巴结有无转移的敏感度为80.9%（34/42）,特异度为98.4%（262/266）,阳性预测值为89.5%（34/38）,阴性预测值为97.0%（262/270）。以术前超声检查评估中央组淋巴结有无转移作为一项评估手段预测颈侧组有无转移,其敏感度为59.5%（25/42）,特异度为92.8%（247/266）。6.4%（17/264）的术前超声检查判断中央组淋巴结无转移患者中术后颈侧组淋巴结有转移。4.3%（8/187）的术中冰冻切片病理检查结果显示中央组淋巴结无转移患者中术后颈侧组淋巴结有转移。结论术前超声检查评估中央组淋巴结有无转移的敏感度较低,因此常规的中央组淋巴结清扫是必要的;术前超声检查评估颈侧组淋巴结有无转移的敏感度及特异度均较高,术前超声怀疑颈侧组淋巴结有转移的患者行颈侧区淋巴结的清扫是必要的。     

18F-FDG PET/CT诊断非小细胞肺癌纵隔淋巴结转移

目的 探讨¹⁸F-FDG PET/CT诊断非小细胞肺癌（NSCLC）纵隔淋巴结转移的价值。方法 回顾性分析130例初诊NSCLC患者（337个纵隔淋巴结）术前PET/CT资料,与术后病理结果相对照,评价PET/CT诊断NSCLC纵隔淋巴结转移的灵敏度、特异度及准确率。结果 以患者为观察单位,PET/CT发现纵隔淋巴结转移66例,无纵隔淋巴结转移64例,灵敏度79.41%（54/68）,特异度80.65%（50/62）,准确率80.00%（104/130）,阳性预测值81.82%（54/66）,阴性预测值78.13%（50/64）;以淋巴结数为单位,PET/CT诊断纵隔淋巴结转移125个,非纵隔淋巴结212个,PET/CT诊断纵隔淋巴结转移的灵敏度74.42%（96/129）,特异度86.06%（179/208）,准确率81.60%（275/337）,阳性预测值76.80%（96/125）,阴性预测值84.43%（179/212）。PET/CT结果与病理结果比较差异无统计学意义。结论 ¹⁸F-FDG PET/CT诊断NSCLC纵隔淋巴结转移具有较高价值。     

术前磁共振检查及术中探查对I型子宫内膜癌系统淋巴清扫评估的临床价值分析

目的通过术前磁共振(MRI)检查及术中探查对I型子宫内膜癌(EC)系统清扫淋巴结术后病理符合率比较,探讨是否可避免不必要的淋巴清扫。方法回顾性选取2015年4月至2019年4月在我院治疗的134例I型EC患者,进行术前MRI检查与术中探查在淋巴结转移和肌层有无浸润的评估与术后病理在灵敏度、特异度、准确度、阳性预测值及阴性预测值符合率的比较。并计算ROC曲线面积。结果术前MRI诊断淋巴结阳性的敏感度57.1%,特异度85.8%,准确度82.8%,阳性预测值32.0%,阴性预测值94.5%。术中探查诊断淋巴结阳性的敏感度71.4%,特异度88.3%,准确度86.6%,阳性预测值41.7%,阴性预测值96.4%。即两者阴性预测值均较高:94.5%,96.4%。术前MRI诊断淋巴结是否转移及肌层有无浸润与术后病理相比ROC曲线面积分别为0.732,0.714。术中探查判断淋巴结是否转移与术后病理相比ROC曲线面积为0.767。其余ROC曲线面积0.7,无实用意义。结论术前MRI检查及术中探查对I型EC判断淋巴结是否转移及肌层有无浸润的评估与术后病理金标准比较阴性预测率较高,有较好的临床应用价值,可避免不必要的系统淋巴结清扫。     

MSCT引导TBNA联合LCT技术在诊断纵隔淋巴结肿大中的应用研究

目的探讨胸部CT影像学(MSCT)引导经支气管针吸活检术(TBNA)联合液基细胞学(LCT)技术在诊断纵隔淋巴结肿大中的应用价值。方法回顾性分析2011年8月～2015年4月间在宝鸡市中心医院224例行胸部CT检查发现纵隔淋巴结肿大病例,均行TBNA检查,总结穿刺结果,评价该技术的诊断价值和安全性。结果①224例患者经TBNA检查7个部位共394组淋巴结,TBNA穿刺成功788针(96.10%)。②190例恶性肿瘤患者中,TBNA结果阳性180例(94.74%),其中64例患者TBNA结果是惟一病理学依据。③44例TBNA阴性患者中,除12例经过TBNA确诊为结节病外,其余经开胸手术确诊,2例为淋巴瘤,8例为纵隔淋巴结转移癌,22例阴性。在纵隔淋巴结肿大诊断中敏感度、特异度和准确度分别为94.76%,100%和95.54%。④64例患者行肺癌根治术,以术后淋巴结病理结果为参考,TBNA判断肺癌纵隔淋巴结分期诊断的敏感度、特异度、准确度、阳性预测值和阴性预测值分别是96.05%,100%,96.51%,100%,76.92%。⑤小细胞肺癌TBNA的阳性率高于非小细胞肺癌,差异有统计学意义(χ2值为10.24,P＜0.01)。直径≥3　cm淋巴结TBNA的阳性率稍高于＜3 cm淋巴结,差异无统计学意义(χ2值为1.72,P＞0.05)。结论MSCT引导TBNA联合LCT技术在诊断纵隔淋巴结肿大中敏感度、准确度等均大大提高,且安全易行,值得基层医院临床推广应用。     

直肠癌术前CT诊断与术后病理对照研究

目的 探讨CT检查在直肠癌术前诊断中的临床应用价值.方法 回顾性分析经手术病理证实的67例直肠癌患者的CT表现,其中男38例,女29例,与术后病理结果 进行对照,分析CT分期和病理分期中的各项准确性指标,评价CT检查的临床价值.结果 直肠充气CT扫描对67例直肠癌患者的诊断准确率为100%;诊断直肠癌侵犯浆膜外脂肪的阳性预测值、阴性预测值、敏感度、特异度、假阳性、假阴性分别为94.6%、72.7%、94.6%、72.7%、27.3%、5.4%;诊断盆腔区域淋巴结转移的阳性预测值、阴性预测值、敏感度、特异度、假阳性、假阴性分别为74.2%、69.4%、67.6%、75.8%,24.2%、32.4%;CT分期和病理分期Ⅰ-Ⅲ期的符合率分别为75.0%、68.8 oA、74.2%,总符合率为71.6%.结论 CT检查 能准确的检出直肠癌,并能准确的显示浆膜外脂肪的侵犯,但直肠癌的CT分期和对淋巴结转移的判定仍有限制.     

电视纵隔镜在胸部疾病诊断中的初步体会

目的 探讨电视纵隔镜对胸部疾病诊断价值。方法 38例患者接受了经颈纵隔镜检查术，术前未获得明确病理诊断的纵隔疑难疾病16例，高度怀疑为肺部恶性肿瘤3例，已明确诊断肺癌且影象学显示纵隔淋巴结肿大（≥1．0cm）19例。结果 16例纵隔肿瘤或纵隔不明原因的肿大淋巴结经颈纵隔镜后经病理明确诊断为：结核3例．恶性胸腺瘤2例、纵隔淋巴结淋巴滤泡增生2例、肺炎性假瘤2例，转移性肺癌1例、转移性甲状腺癌1例、成熟性畸胎瘤1例、结节病1例和肺炎性假瘤1例，余2例未能确诊；诊断符合率为87．5％。3例临床怀疑为肺部肿瘤，经颈纵隔镜检查1例诊断为结核；2例未能确诊，后经胸腔镜和剖胸探查诊断，1例为肺非霍奇金淋巴瘤，1例为肺炎性假瘤。19例肺癌纵隔镜诊断纵隔淋巴结转移的灵敏度为86．4％，特异度为100％。全组术后出血1例，无其他合并症。结论 纵隔镜对诊断纵隔肿瘤和对肺癌的分期安全准确。     

乳腺癌患者腋中组转移性淋巴结的声像学特征分析

目的：利用高频超声探讨乳腺癌患者腋中组转移性淋巴结的声像学特征。方法2008年1月至2013年10月在中山大学肿瘤防治中心行超声检查,并发现腋中组存在淋巴结病例共89例,均为女性乳腺癌患者,其中66例为乳腺癌首诊患者,23例为乳腺癌术后复查患者。观察腋中组淋巴结的数量、最大径、纵横比及是否存在淋巴门、血流情况。统计学分析出有意义的参数,并计算其敏感度、特异度、阳性预测值及阴性预测值。结果超声检查发现腋中组淋巴结数量≥3个,诊断淋巴结良恶性的敏感度为56.8%,特异度为89.7%,准确性为71.9%,阳性预测值和阴性预测值分别为87.9%和61.4%;若腋中组有一个淋巴结最大径≥10 mm,则诊断淋巴结良恶性的敏感度为58.0%,特异度为79.5%,准确性为67.4%,阳性预测值和阴性预测值分别为78.4%和59.6%;如果同时存在两个声像学特征,则可明显提高诊断的敏感度（87.8%）和准确性（78.6%）,特异度为60.0%,阳性预测值为72.3%,阴性预测值为80.0%。结论腋中组淋巴结的数量和大小是判断淋巴结良恶性有意义的声像图指征。     

CT能谱成像在诊断肺癌淋巴结转移中的价值

目的:研究并探讨CT能谱成像在诊断肺癌淋巴结转移中的应用价值。方法:选取2014年1月～2016年10月期间我院收治的80例肺癌患者作为研究对象,所有患者均接受CT能谱成像检查,对其胸腔内淋巴结的CT能谱曲线斜率进行计算,比较转移性淋巴结与非转移性淋巴结的能谱曲线斜率,并以病理组织学诊断结果作为金标准,对CT能谱成像诊断肺癌淋巴结转移的诊断灵敏度、特异度、准确度、阳性预测值、阴性预测值进行计算。结果:80例肺癌患者经CT能谱成像分析,共发现29例转移性淋巴结、51例非转移性淋巴结,转移性淋巴结的CT能谱曲线斜率明显低于非转移性淋巴结(P0.05)。经病理组织学诊断得出,80例肺癌患者中共有31例淋巴结转移,CT能谱成像对肺癌淋巴结转移的诊断灵敏度、特异度、准确度、阳性预测值、阴性预测值分别为90.32%、97.96%、95.00%、96.55%、94.12%,与病理组织学诊断结果之间的一致性良好(Kappa=0.723)。结论:采用CT能谱成像对肺癌淋巴结转移情况进行判断具有较高的准确性,可作为术前淋巴结转移评估的重要手段,为手术方案的制定提供指导意见。     

超声支气管镜引导经支气管针吸活检术在胸部疾病的诊断价值

目的评价超声支气管镜引导下经支气管针吸活检术(EBUS-TBNA)在胸部疾病诊断中的应用价值。方法回顾分析100例经胸部影像学检查(CT或PET-CT)诊断为胸内气管或支气管旁肿块及肺门和(或)纵隔淋巴结肿大的患者行EBUS-TBNA的资料,统计EBUS-TBNA诊断的特异性、准确率、敏感度以及阳性预测值和阴性预测值。结果 (1)已确诊或怀疑肺癌72例,经EBUS-TBNA检查证实纵隔淋巴结转移52例。EBUS-TBNA检查阴性者中,18例接受胸腔镜或开胸手术,其中有12例肺癌术后病理证实纵隔淋巴结未见转移,3例肺癌出现纵隔淋巴结转移,其余3例为肺良性病变;EBUS-TBNA在本研究中肺癌纵隔淋巴结分期中的特异性、敏感度和准确性分别为100%(12/12)、94.5%(52/55)和95.5%(64/67);阳性预测值及阴性预测值分别为100%(52/52)和80%(12/15)。(2)不明原因的纵隔和(或)肺门淋巴结肿大以及纵隔肿物16例,经EBUS-TBNA检查后明确恶性病变5例,良性病变11例;EBUS-TBNA在纵隔病变良恶性诊断方面的敏感性和准确性分别为83.3%(5/6)和93.8%(15/16)。(3)大气道旁肺内病变12例,经EBUS-TBNA检查后明确肺癌10例,EBUS-TBNA在大气道旁肺内病变中诊断的敏感性和准确率分别为90.9%(10/11)和91.7%(11/12)。所有患者检查耐受良好,无严重并发症出现。结论在胸部疾病诊断中EBUS-TBNA是一种安全、有效的诊断手段。     

Measurement of L-carnitine and acylcarnitines in body fluids and tissues in children and in adults

We have developed a reliable and validated radio-enzymatic method for the assay of L-carnitine and acylcarnitines, using a modification of existing methods. The sensitivity of the assay is 10 mumol/l using 10 microliters of plasma or urine. It is also suitable for measurements of carnitine in a 10 mg sample of liver or muscle obtained by percutaneous biopsy. The use of N-ethylmaleimide in the reaction mixture together with an excess of [1-14C]acetyl CoA ensures that the reaction proceeds to completion and a linear response is obtained. Using this method control ranges have been established for plasma and urine carnitine concentrations in healthy children and adults, and for the carnitine content of liver and muscle in adults. No significant difference was found between fasting and post-prandial plasma carnitine levels. An age-related increase was found in urinary total carnitine and acylcarnitine concentration throughout childhood. These data provide a reliable basis for studies of patients with abnormal carnitine and acylcarnitine metabolism, distribution and excretion.     

Activity of amikacin and ampicillin in succession and in combination

One strain each of Escherichia coli and Streptococcus faecalis were exposed to amikacin and ampicillin in combination as well as in succession. Exposure to ampicillin for 1 hr followed by amikacin for 3 or 4 hr had the greatest antibacterial activity when the antibiotics were applied in succession. The least effective exposures for both organisms were 1 hr to amikacin followed by 3 or 4 hr to ampicillin. Exposure to the antibiotics in combination each at 1 MIC had the overall greatest antibacterial activity. Simultaneous exposure to the antibiotic combination does not necessarily mean simultaneous activity of both ampicillin and amikacin on the E. coli. The cell wall autolytic activities produced by ampicillin are triggered within 10 min after physical contact with the bacteria. In contrast, amikacin requires at least 30 min after physical contact to manifest its activity on the ribosome. Although physical exposure to both antibiotics in the combination is simultaneous, the specific activity of each is in fact sequential, with ampicillin acting first. This explains the synergistic effect of the combination. It appears, therefore, that the synergistic or antagonistic affect of a drug combination is determined by the sequence and timing of the antibacterial manifestations of its components.     

纤维支气管镜在儿童咯血诊断与治疗中的应用

目的 评价纤维支气管镜术在儿童咯血病因诊断及治疗中的价值以及安全性.方法 应用用日本产Olympus BF 3c-40纤维支气管镜(最小外径3.6 mm)给58名咯血原因不明的患者行纤维支气管镜检查,并予镜下局部止血治疗.判断出血部位、观察病变情况和出血的原因、临床表现、其他辅助检查、治疗及转归等进行综合分析.结果 引起咯血的主要疾病为气管支气管、肺部的炎症24例(41.3%)、支气管内膜结核12例(20.7%)、支气管异物8例(13.7%)、特发性肺含铁血黄素沉着症7例(12.1%)、支气管扩张4例(6.9%)、心肺血管发育异常1例,原因不明2例.诊断阳性率为96.5%.镜下发现有活动性出血18例,镜下局部止血治疗后显效者10例,有效者8例,有效率为100%.术中并发短暂低氧血症(SaO2＜85%,＜20 s)15例,加大吸氧流量后均改善;术后发热3例均为低热,24 h后热退.结论 纤维支气管镜检查可明确出血部位及原因并可进行局部治疗,且安全的有效.     

Sites of in vivo extraction and interconversion of testosterone and androstenedione in dogs

The interconversion and extraction of testosterone and androstenedione across and within different tissues or areas have been studied by the constant infusion technique. The results were calculated using the (3)H/(14)C ratios and radioactive concentrations of testosterone and androstenedione obtained from afferent and efferent blood and tissues at equilibrium. In each tissue studied, the interconversion between testosterone and androstenedione inside the tissue was significantly higher than the corresponding interconversion across the tissue. The pulmonary contribution to the total interconversion between testosterone and androstenedione was far more important than that of any of the other tissues studied. The hepatic metabolic clearance rates of testosterone and androstenedione were not different from their metabolic clearance rates in the mesenteric area. The extraction of each of these compounds, although not negligible, was lower in the kidney and the femoral bed compared with the extraction in the liver and the mesenteric area. Finally, with the possible exception of the liver, testosterone and androstenedione were more completely metabolized when they originated from the cells than from afferent blood.The evaluation of these different tissue transfer constants provides more precise information concerning the relative importance of different sites in the metabolism of these interconverting hormones.     

Evaluation of aprotinin and tranexamic acid in different in vitro and in vivo models of fibrinolysis, coagulation and thrombus formation

BACKGROUND: The serine protease inhibitor aprotinin and plasminogen inhibitor tranexamic acid are used in coronary artery bypass graft (CABG) surgery to reduce bleeding. Clinicians may consider these agents as readily substitutable regarding their pharmacological profiles. OBJECTIVE: These agents were evaluated in assays of hemostasis to elucidate their underlying mechanism(s) of action. METHODS: In human plasma, effects on both clot fibrinolysis and coagulation were spectrophotometrically quantified in vitro. Rat-tail bleeding and arteriovenous shunt thrombus formation models were conducted in vivo. RESULTS: Fibrinolysis was inhibited by aprotinin (IC(50), 0.16 +/- 0.02 micromol L(-1)) and tranexamic acid (IC(50), 24.1 +/-1.1 micromol L(-1)). In vivo, aprotinin dose-dependently reduced rat-tail bleeding time (minimal effective dose, 3 mg kg(-1) bolus plus 6 mg kg(-1 )h(-1) infusion); tranexamic acid reduced bleeding time (minimal effective dose, 100 mg kg(-1) h(-1)). In vitro, coagulation time was doubled by aprotinin at 3.2 +/- 0.2 micromol L(-1), while tranexamic acid showed no effect at concentrations up to 3 mmol L(-1). Aprotinin inhibited thrombus formation in vivo in a dose-dependent manner (minimal effective dose, 3 mg kg(-1) bolus plus 6 mg kg(-1) h(-1) infusion). Conversely, tranexamic acid dose-dependently increased thrombus formation and thrombus weight (minimal effective dose, 100 mg kg(-1 )h(-1) infusion). CONCLUSIONS: These data show that aprotinin and tranexamic acid have differential effects on hemostasis and are not necessarily substitutable with respect to mechanism of action. Although both agents have been shown to reduce bleeding in patients undergoing CABG, their divergent effects on thrombus formation observed in vitro and in vivo should be critically evaluated clinically.     

Noradrenaline and Adrenaline in Blood and Urine in a Case of Phaeochromocytoma

A case of phaeochromocytoma is described in which X-ray investigation and pharmacodynamical tests with tetraethyl-ammonium and Regitin were non-informative. The diagnosis was established by the increased excretion of catechols with the urine (1010–2400 μg noradrenaline and 16–19 μg adrenaline per 24-hour period).

Estimation of catechols in samples of the blood and of the urine from the same period showed an average blood level of 3.6 μg/100 ml noradrenaline and a corresponding urinary output of 110 μg per hour.

The high systolic and diastolic blood pressure, the electrocardiographic changes, the increased basal metabolic rate, the response to the glucose tolerance test, sweating, eosinopenia and fatigue are explained as symptoms and signs of hypernoradrenalinemia.

Biological estimation of the catechols in the tumor, which weighed 40 g, showed 590 μg/g noradrenaline and 12 μg/g adrenaline.

After operation the blood pressure and the level of the urinary catechols returned to normal.     

Population pharmacokinetics and pharmacogenetics of alcohol in Chinese and Indians in Singapore

What is known and Objective:  Interindividual variability in alcohol pharmacokinetics is influenced by a number of factors, including polymorphisms in genes mediating alcohol pharmacology, ethnicity, sex and body size. Several studies have evaluated the population pharmacokinetics of alcohol from breath alcohol measures. None of these studies, however, have evaluated ethnicity and alcohol‐metabolizing enzyme genotypes as covariates in their population pharmacokinetic modelling. We aimed to develop a population pharmacokinetic model using clinical and genetic factors and to identify covariates that influenced interindividual variability in alcohol clearance and volume of distribution. Methods:  Hundred and eighty healthy subjects (90 Chinese and 90 Indians; 45 males and 45 females from each ethnic group) ingested a vodka–orange juice mixture to simulate social drinking. Subjects were genotyped for the ADH1B (Arg48His), ALDH2 (Glu504Lys) and CYP2E1 (c.‐1293G>C and c.‐1053C>T) polymorphisms. A base pharmacokinetic model was developed using the nonmem software (NONMEM Project Group, University of California, San Francisco, San Francisco, CA, USA) to determine the alcohol clearance and volume of distribution. The model was extended to include covariates that influenced the between‐subject variability. Results and Discussion:  Body weight and sex significantly influenced absorption rate and volume of distribution of alcohol. Body weight and ADH1B Arg48His polymorphism significantly influenced alcohol clearance. The Michaelis–Menten elimination rate (V_max) was decreased by 10% in homozygous ADH1B*1/*1 subjects. Ethnicity was not determined to be a significant covariate in the final population pharmacokinetic model. What is new and Conclusion:  Gender and body weight were covariates that contributed most to explaining the observed interindividual alcohol pharmacokinetic variability. Of the four SNPs examined in this study, only ADH1B Arg48His polymorphism had a significant, though modest, effect on the pharmacokinetics of alcohol.     

Safety and efficacy of linezolid in 16 infants and children in Japan

Linezolid, an oxazolidinone antibiotic, exhibits a broad spectrum of activity against Gram-positive bacteria. It has been licensed for adult use in Japan since 2006 for MRSA infections, and has also been used off-label for pediatric patients. At our university hospital, a total of 16 infants and children (including one non-Japanese Asian) were administered linezolid owing to infection with multidrug-resistant Gram-positive bacteria, after consent had been provided. All patients had severe underlying diseases or indications for surgery. Eighty-eight percent of the causal microorganisms were methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant coagulase-negative Staphylococcus and all were sensitive to linezolid. Linezolid was administered because the antecedent anti-MRSA medications were ineffective or contraindicated, or intravenous-to-oral switch therapy was requested owing to cardiac or orthopedic surgical-site infections. The median duration of administration was 13 days (range 3-31 days). The overall efficacy was 91 % (10/11) in those for whom efficacy could be evaluated. Only two patients (both teen-aged) encountered linezolid-related adverse effects (13 %, 2/16). One patient showed elevation of liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), requiring that administration be withdrawn, but enzyme levels returned to normal after the patient had been switched to vancomycin. The other patient showed transiently decreased platelet counts. Linezolid is considered generally safe and effective for children in Japan, especially for those who cannot use other anti-MRSA medications or those who require oral antibiotics for infections with multidrug-resistant Gram-positive bacteria.