人巨细胞病毒肝炎综合征婴儿外周血宿主microRNA表达的变化北大核心CSCD

目的观察人巨细胞病毒（HCMV）所致肝炎综合征婴儿治疗前后外周血microRNA（miRNA）水平变化,探讨宿主miRNA与更昔洛韦（GCV）疗效的关系及临床意义。方法收集HCMV感染所致肝炎综合征婴儿44例为病例组,分为GCV不敏感组（20例）和GCV敏感组（24例）;15例同期体检健康婴儿为健康对照组。分别在GCV治疗前2d和停药后（或用药4周末）,采集患儿外周静脉血1mL,提取miRNA,采用SYBRGreenI实时荧光定量PCR方法检测hsa—miR一92a、hsa—miR一96、hsa—miR-433和hsa—miR一183表达水平,结果用相对表达量表示。结果病例组hsa—miR-92a、hsa—miR一96、bsa—miR-433和hsa—miR一183表达水平均高于健康对照组,差异均有统计学意义（P均〈0．05）;治疗前GCV不敏感组hsa—miR-96表达水平（1．24±0．62）低于GCV敏感组患儿（5．43±1,11）,差异有统计学意义（t：一2．41,P=0．02）;治疗后GCV不敏感组hsa—miR-96（0．70±0．06）和hsa—miR一183（2．97±0．14）均明显低于敏感组（6．47±1．01、9．84±0．95）,差异均有统计学意义（t’=一5．46,P〈0．01;t=一2．52,P=0．019）;GCV不敏感组hsa—miR一183治疗后（2．974-0．14）较治疗前（9．79±1．31）明显下降,hsa—miR-433治疗后（6．20±0．92）较治疗前（10．90±0．77）表达水平下降,差异均有统计学意义（t=一3．54,P=0．002;t：2．45,P=0．027）;GCV敏感组hsa—miR-183表达水平治疗后（9．84±0．95）较治疗前（9．27±0．96）升高,hsa—miR-433治疗后（6．57±0．71）较治疗前（9．88±1．32）下降,差异均有统计学意义（t=-2．54,P=0．018;t=3．70,P〈0．001）。结论GCV敏感患儿用药前后hsa—miR-96表达均高于不敏感患儿,用药后敏感患儿hsa-miR一-83表达也高于不敏感患儿,miRNA对临床治疗婴儿肝炎综合征具有指导意义。     

不同疗程更昔洛韦治疗婴儿巨细胞病毒性肝炎的疗效

目的 观察不同疗程更昔洛韦(GCV)治疗婴儿巨细胞病毒性肝炎(CMV肝炎)的效果及不良反应.方法 选取2009年1月-2010年12月在本科住院的1～4月龄CMV肝炎患儿48例,随机分为治疗1组(n=25)和治疗2组(n=23).二组均予保肝、退黄治疗,治疗1组给予GCV 5 mg·kg-1,每日2次,连用2周.治疗2组诱导期给予GCV 5 mg·kg-1,每日2次,连用2周;维持期给予GCV 5 mg·kg-1,每日1次,连用7 d.治疗前后常规检查肝、肾功能及心肌酶谱,所有患儿出院后随访2个月,监测其血CMV-IgM水平.结果 二组患儿治疗后血清ALT、总胆红素、结合胆红素水平均显著下降,与治疗前比较差异均有统计学意义(Pa＜0.05);治疗后二组ALT、总胆红素及结合胆红素水平比较差异亦有统计学意义(Pa＜0.05).治疗后随访2个月,血CMV-IgM转阴率治疗2组高于治疗1组.血常规、肾功能及心肌酶谱二组比较无统计学差异(Pa＞0.05).结论 GCV治疗婴儿CMV肝炎的疗效肯定,且 3周二期治疗方案优于2周一期治疗方案,前者能够获得高病毒转阴率和较低复发率,同时较长程疗法更少引起不良反应,较经济且易于被小婴儿耐受,易于推广.     

血浆miRNA在儿童急性淋巴细胞白血病中表达特点

目的研究血浆miRNAs(hsa-let-7d-5p、hsa-miR-27a-3 p、hsa-miR-29a-3p、hsa-miR-197-3p、hsa-miR-652-3p)在儿童急性淋巴细胞白血病(ALL)不同疾病状态的表达特点。方法选取北京儿童医院2009年1月-2013年12月住院的ALL患儿血浆标本70例次,包括初诊-缓解配对30对,复发10例;对照组为2013年8月在北京儿童医院进行健康体检的志愿者30例。采用不提取RNA而直接RT-PCR方法检测患儿血浆中5种miRR NAs的表达情况,分析其表达与儿童ALL的诊断、治疗以及与TEL/AML1融合基因之间的关系。结果 5种miRNAs表达水平均呈现初诊组表达水平低于正常组,缓解后表达水平升高,而复发后表达水平再次明显降低的特点,各组间比较差异有显著性(P0.05);5种miRNAs对儿童ALL的诊断效能提示:ROC曲线下面积(AUC)均≥0.844,其中以hsa-let-7d-5p表达最高,AUC=0.956;在初诊组和缓解组,5种miRNAs的表达情况在有无TEL/AML1融合基因患儿血浆间差异无显著性(P0.05)。结论血浆中hsa-let-7d-5p、hsa-miR-27a-3p、hsa-miR-29a-3p、hsa-miR-197-3p、hsa-miR-652-3p在儿童ALL的发病过程中可能起到抑癌基因的作用,这为血浆miRNA用于儿童ALL的诊断、治疗及预后监测的分子标记物提供了一定的依据。     

东莨菪碱改善先天性室间隔缺损合并肺动脉高压患儿体外循环术后氧合指数的效果探讨

目的检测东莨菪碱改善先天性室间隔缺损(VSD)合并肺动脉高压(PH)患儿体外循环(CPB)术后氧合指数(OI,PaO_2/FiO_2)的效果。方法将49例VSD合并PH患儿随机分为两组,治疗组26例,均在麻醉前30分钟肌肉注射东莨菪碱(0.01 mg/kg)和术后静脉注射东莨菪碱(初始剂量0.03~0.05 mg·kg~(-1)·h~(-1));对照组23例,不用此类药物。两组其它治疗方案均相同。监测和对比两组患儿术后6 h内平均OI、平均气道峰压、机械通气时间,以及拔管后IO,以评价东莨菪碱的疗效。结果治疗组术后6 h内平均OI为(268.5±58.0)mmHg,对照组为(233.5±40.8)mmHg,经统计学分析差异有意义(t=2.402,P=0.011);治疗组平均气道峰压(21.2±2.2)cmH_2O,对照组为(22.0±3.2)cmH_2O,经统计学分析差异无意义(t=0.979,P=0.164);机械通气时间治疗组(13.7±7.9)h,短于对照组的(19.7±13.0)h,经统计学分析差异有意义(t=1.935,P=0.029);治疗组拔管后氧合指数为(285.0±32.3)mmHg,对照组(243.7±40.1)mmHg,差异有统计学意义(t=3.897,P=0.001)。2例患儿出现用药不良反应(腹胀)。结论东莨菪碱的适量应用能明显提高VSD合并PH患儿CPB术后OI,缩短术后机械通气时间。     

川崎病患儿外周血单个核细胞中γ干扰素诱导蛋白10表达的意义

目的探讨川崎病(KD)患儿外周血单个核细胞(PBMC)中γ干扰素诱导蛋白-10(IP-10) mRNA表达意义。方法实时荧光定量反转录聚合酶链反应(real-time RT-PCR)检测42例KD及40例健康儿童PBMC中IP-10 mRNA表达。结果KD组PBMC中IP-10 mRNA表达水平为0.741±0.161,明显高于健康对照组0.388±0.063(t=12.988 P=0);KD冠状动脉损伤(CAL)亚组PBMC中IP-10 mRNA表达水平为0.825±0.142,高于无冠状动脉损伤(non-CAL)亚组0.708±0.158(t=2.233 P=0.031);静脉注射人免疫球蛋白(IVIG)治疗后IP-10 mRNA表达水平为0.421±0.119,较治疗前0.728±0.170下降(P<0.05),与健康对照组比较无显著性差异(P>0.05);未予IVIG治疗者常规治疗后IP-10 mRNA表达水平为0.674±0.140,较常规治疗前0.780±0.131轻度下降,但无显著性差异(P>0.05)。结论IP-10在KD患儿PBMC中表达增加,参与KD的发病过程,并与KD CAL发生有关,对PBMC中IP-10 mRNA表达抑制可能是IVIG治疗KD的作用机制之一。     

特异性免疫治疗对哮喘患儿自然杀伤细胞和嗜碱性细胞的影响

目的探讨特异性免疫治疗哮喘患儿NK细胞活性和嗜碱性细胞表达变化的意义。方法将60例轻、中度哮喘患儿(均对屋尘螨过敏)分为两组,其中治疗组30例,采用屋尘螨特异性免疫治疗联合吸入糖皮质激素为主的哮喘防治方案;对照组30例,仅采用吸入激素为主的哮喘防治方案。检测两组治疗前后NK细胞活性和嗜碱性粒细胞表达以及血清总IgE、屋尘螨特异性IgE(DP-IgE)、嗜酸性细胞阳离子蛋白(ECP)水平,评价两组患儿治疗前后哮喘急性发作次数,比较治疗前后哮喘控制测试(C-ACT)评分和最大用力呼气峰流速(PEF)测试结果。结果治疗组治疗后外周血NK细胞活性(12.01±1.41)%,明显高于对照组(10.11±2.49)%(t=3.83,P=0.00)。治疗组治疗后嗜碱性粒细胞含量、血清总IgE及DP-IgE水平下降程度均明显高于对照组(Z=2.23~3.57,P均<0.05);治疗后两组哮喘急性发作次数较治疗前均明显减少,C-ACT评分和PEF结果较治疗前均有提高,治疗组更优于对照组,差异有统计学意义(t=3.63~4.02,P均<0.01)。结论特异性免疫治疗联合规范化防治使哮喘患儿病情更趋稳定,哮喘控制效果更理想。特异性免疫治疗能显著提高机体NK细胞活性、减少嗜碱性粒细胞含量。     

小剂量阿奇霉素对哮喘儿童气道反应性的影响

目的 探讨小剂量阿奇霉素对哮喘儿童气道反应性的影响.方法 中重度持续哮喘患儿104例分为A组(56例)和B组(48例).所有患儿均应用沙美特罗替卡松(50/100μg/剂)2剂/d,吸人4周,重度持续哮喘患儿加服孟鲁司特5 mg/d,合并过敏性鼻炎者加糠酸莫米松100～200μg/d喷鼻,然后进入观察期.A组继续吸入沙美特罗替卡松(剂量同前),并加口服阿奇霉素7.5 mg/( kg·d)(最大剂量250 mg/d),每周服药2d;B组仅继续吸入沙美特罗替卡松(剂量同前).观察期为12周.试验结束两组分别评定观察期内有症状天数;开始及结束时,两组分别检测一秒钟用力呼气量( FEV1)、最大呼气峰流量(PEF)占预计值的百分率,观察期第15天及结束时检测使FEV1下降20％的组胺激发剂量(PD20-FEV1);观察开始前24h及结束后24h分别检测24h尿17-羟皮质醇(17-OHCS)和17-酮皮质醇(17-KS);试验结束后2周检测血清丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST).结果 (1)A、B两组有症状天数分别为(2.13±1.18)d、(2.25±1.19)d,差异无统计学意义(t =0.54,P=0.59).(2)观察前、后PEF占预计值百分率:A组分别为(49.77±15.02)％、(82.73±7.81)％,差异有统计学意义(t=16.59,P=0.000),B组分别为(52.69±13.90)％、(81.15+7.28)％,差异有统计学意义(t=12.37,P=0.000);观察前、后FEV1占预计值百分率:A组分别为(50.48±15.08)％、(83.18±6.61)％,差异有统计学意义(t=16.25,P=0.000),B组分别为(53.29±13.89)％、(82.73±6.10)％,差异有统计学意义(t=12.83,P=0.000).(3)观察期第15天、结束时PD20-FEV1水平:A组分别为(65.13±26.08) μg、(460.79± 221.72) μg,差异有统计学意义(t=13.54,P=0.000),B组分别为(65.27±25.75) μg、(65.66±25.09) μg,差异无统计学意义(t=1.45,P=0.15);观察期结束时A、B两组间PD20 - FEV1水平比较,差异有统计学意义(t=13.29,P=0.000).(4)观察前、后24h尿17 -OHCS水平A组分别为(14.27±3.41) nmol/L、(14.43±3.69) nmol/L,B组分别为(14.31±3.66) nmol/L、(14.56±3.37)nmol/L,两组比较差异均无统计学意义;观察前、后24h尿17-KS水平A组分别为(22.43±5.69)nmol/L、(22.07±5.21) nmol/L,B组分别为(22.40±5.04)nmol/L、(22.54±4.74)nmol/L,两组比较差异均无统计学意义.(5)观察期结束后2周血清ALT水平A、B两组分别为(20.39±9.12)U/L、(20.83±7.83) U/L,差异无统计学意义(t=0.26,P=0.79);AST水平A、B两组分别为(20.68±8.67) U/L、(21.44±8.60) U/L,差异无统计学意义(t=0.45,P=0.66).结论 小剂量阿奇霉素口服12周,并联合沙美特罗替卡松吸入可降低哮喘患儿的支气管高反应性,但未减少患儿的有症状天数,也未使FEV1、PEF较单独应用沙美特罗替卡松改善明显,对患儿肾上腺功能及肝功能无影响.     

哮喘患儿外周血CD4~+T细胞来源瘦素水平的变化

目的检测哮喘患儿外周血CD4+T细胞瘦素表达的水平,探讨其在哮喘发生发展中的作用。方法收集27例哮喘患儿在发作期和缓解期以及25例健康对照儿童的外周血标本,分离外周血单个核细胞(PBMC),再用CD4+T细胞免疫磁珠分离CD4+T细胞,体外培养,酶联免疫吸附试验检测上清液中瘦素水平。采用实时定量PCR方法检测PBMC中孤儿核受体γt(RORγt)相对表达量。结果哮喘发作期、缓解期患儿以及健康对照儿童的CD4+T细胞培养液中瘦素水平分别为(68.46±13.08)pg/ml、(36.73±6.13)pg/ml及(32.82±5.79)pg/ml,三组间差异有统计学意义(P0.01);经两两比较,发作期高于缓解期和健康对照儿童,差异均有统计学意义(P0.01);而缓解期和健康对照儿童的差异无统计学意义(P0.05)。哮喘发作期、缓解期患儿以及健康对照儿童的血浆瘦素水平分别为(16.64±3.53)ng/ml、(14.91±3.24)ng/ml及(13.72±5.79)ng/ml,三组间差异无统计学意义(P0.05)。哮喘发作期、缓解期患儿以及健康对照儿童PBMC中RORγt的相对表达量分别为(0.341±0.175)、(0.089±0.028)及(0.068±0.018),三组间差异有统计学意义(P0.01);两两比较,发作期高于缓解期和健康对照儿童,差异均有统计学意义(P均0.01);缓解期和健康对照儿童的差异无统计学意义(P0.05)。哮喘患儿发作期CD4+T细胞培养液中瘦素水平与PBMC中RORγt相对表达量呈正相关(r=0.681,P0.01)。结论哮喘患儿CD4+T细胞瘦素水平升高,与疾病的发生发展关系密切。     

36例婴儿痉挛患儿血清孕酮与硫酸脱氢表雄酮表达及药物影响的研究

目的 探讨婴儿痉挛患儿血清中孕酮（progesterone,Prog）、硫酸脱氢表雄酮（dehydroepiandrosterone sulfate,DHEAS）水平及丙戊酸钠（sodium valproate,VPA）、拉莫三嗪（lamotrigine,LTG）对患儿Prog和DHEAS水平的影响.方法 以36例未经治疗的婴儿痉挛患儿（病例组）与40例健康婴儿（对照组）为研究对象,应用电化学发光免疫法测定血清Prog及DHEAS水平,并分别对21例单药服用VPA（VPA治疗组）、13例添加LTG（LTG添加治疗组）治疗4个月前后对比,观察各治疗组女婴患儿和男婴患儿性激素的变化.结果 病例组与对照组女婴患儿与男婴患儿血清Prog和log（DHEAS）（经对数转换）水平差异均无统计学意义（P均＞0.05）.VPA治疗组治疗后女婴患儿和男婴患儿血清Prog水平均明显低于治疗前（t=2.603、3.146,P=0.003、0.008）;LTG添加治疗组治疗后女婴患儿和男婴患儿血清log（DHEAS）水平均明显高于治疗前（t=3.185、2.663,P=0.007、0.041）.结论 婴儿痉挛可能并不影响患儿激素代谢,VPA、LTG可影响婴儿激素水平,在治疗期间应该监测患儿血清激素水平.     

Breastfeeding perceptions in communities in Mangochi district in Malawi

Aim: To investigate mothers’ perceptions of breastfeeding and influences from their social network. Methods: A cross‐sectional survey was carried out in Mangochi district, Malawi where questionnaire data from 157 rural and 192 semi‐urban mother–infant pairs were obtained. Results: The proportion of mothers who thought that exclusive breastfeeding should last for 6 months and those who reported to have actually exclusively breastfed were 40.1% and 7.5% respectively. Of those who reported practising exclusive breastfeeding for 6 months, 77.5% stated that exclusive breastfeeding should last for 6 months. This opinion was independently associated with giving birth in a Baby‐Friendly facility, OR = 5.22; 95% CI (1.92–14.16). Among the mothers who thought that exclusive breastfeeding should last for less than 6 months, 43.9% reported having been influenced in their opinion by health workers. Infant crying was the most common (62.4%) reason for stopping exclusive breastfeeding. Conclusion: The findings illustrate the positive impact health workers can have, as well as the need to raise awareness of the benefits of exclusive breastfeeding among both health workers and mothers. Furthermore, continued counselling of mothers on how to deal with stressful infant behaviour such as crying may assist to prolong exclusive breastfeeding.     

胶原成分在儿童系膜增生性肾小球肾炎中的变化

目的观察系膜增生性肾小球肾炎（ＭｓＰＧＮ）系膜区胶原成分的变化。方法应用链菌素亲生物素过氧化酶连接法观察了３０例轻度ＭｓＰＧＮ肾穿刺活组织标本和正常的肾小球系膜区Ⅳ型胶原及其α链（α１、α３、α５链）、Ⅵ型胶原及Ⅰ型胶原的变化。结果（１）正常肾脏组织中，Ⅳ型胶原及其α１（Ⅳ）链分布于系膜区和基底膜，α３（Ⅳ）、α５（Ⅳ）链分布于基底膜，Ⅵ型胶原分布于系膜区、肾小球基底膜和间质，Ⅰ型胶原仅分布于肾间质。（２）在轻度ＭｓＰＧＮ时，系膜区内Ⅳ型胶原及其α１链、Ⅵ型胶原含量较正常对照明显增多（Ｐ＜０．０１）；当系膜区系膜细胞超过４个时，Ⅰ型胶原开始在肾小球内出现，且在硬化肾小球内Ⅰ型胶原均呈阳性；α３（Ⅳ）、α５（Ⅳ）链与正常对照比较无明显变化，硬化肾小球α３（Ⅳ）、α５（Ⅳ）染色呈阳性。结论系膜区胶原成分增多可先于系膜细胞增生，并随系膜细胞增生而增多，间质胶原成分Ⅰ型胶原，不但出现于硬化肾小球内，而且出现于系膜细胞增生较重时     

Cardiomyopathy in children in Ahmedabad

A clinical study and follow up of 20 children with cardiomyopathies upto age of 16 years are presented. The DCM was most common variety followed by RCM and HCM in pediatric age group. SHMD presenting with cardiomyopathy were common in infancy and early childhood. Cardiomyopathies presented most frequently between 2–5 years and 10–16 years age group with DCM having almost equal distribution. Clinical presentation of various types is described, despite of vigorous decongestive and vasodilator treatment in advanced cases, course was rapidly downhill and prognosis is poor in general.     

Achalasia in siblings in infancy

Achalasia is rare in children, more so familial. We report two siblings with familial achalasia who presented in their infancy with vomiting and failure to thrive. Achalasia can be misdiagnosed as upper gastrointestinal obstruction as happened in one of our siblings. Esophageal contrast roentgenography is diagnostic. Both the children were treated successfully by transabdominal esophagomyotomy with fundoplication.     

哮喘大鼠气道重塑中尾加压素-的表达变化

目的：研究哮喘大鼠气道重塑血清和支气管肺泡灌洗液（BALF）中尾加压素 Ⅱ（U-II）含量的变化及其作用。方法：32只雄性Sprague-Dawley大鼠随机分为正常对照组、哮喘2周组、哮喘4周组和哮喘8周组,每组8只。以卵清白蛋白(OVA)致敏与激发建立哮喘大鼠气道重塑模型,图像分析技术测量大鼠支气管壁总面积和平滑肌面积,计算单位基底膜周径(Pbm)的支气管壁厚度(Wat)和平滑肌厚度(Wam),ELISA法测定血清和BALF中U-II的含量。结果：哮喘各组Wat及Wam均明显高于正常对照组（P<0.01）;哮喘组血清和BALF中U-II含量均显著高于正常对照组（P<0.01）,其中哮喘8周组血清和BALF中U-II含量显著高于哮喘4周组和哮喘2周组（P<0.01）,哮喘4周组也显著高于哮喘2周组（P<0.01）。各组大鼠BALF中的U-II含量与Wat及Wam呈正相关,BALF与血清中U-II含量亦呈正相关。结论：哮喘大鼠气道重塑血清和BALF中U-II含量增加;且U-II含量的变化与气道重塑相关。［中国当代儿科杂志,2010,12（4）：287-289］     

北京地区2007年儿童A群轮状病毒腹泻的流行病学研究

目的 研究北京地区急性腹泻儿童中A群轮状病毒(RV)感染的流行病学特点.方法 收集2007年4月至12月我院肠道门诊就诊的2039例急性腹泻患儿的粪便标本,采用标记金的A群RV单克隆抗体,以免疫层析双抗体夹心法定性检测A群RV抗原.结果 2039份粪便标本中,621份检测到A群RV,总检出率为30.5%(621/2039),其中男430例(69.2%),女191例(30.8%).RV感染者中,以6个月～2岁年龄段的患儿为最多,共571例(91.9%).检出率以10～12月份最高,均在30%以上,其中高峰出现在11月份,达43.4%.北京地区18个区县的统计数据显示,距市区较近的区县RV抗原检出率较低,边远区县较高.少部分患儿合并肠道细菌感染.结论 A群RV为北京地区2岁以下儿童急性腹泻病的主病原,6个月～2岁婴幼儿是A群RV的易感人群,10～12月份为北京地区的流行高峰.在流行季节对肠道细菌感染患儿常规进行A群RV抗原检测有助于避免漏诊和进行更合理的治疗.     

转流术治疗小儿精索静脉曲张

目的 采用转流术治疗小儿精索静脉曲张，重新建立精索静脉通道，使静脉回流受阻立即得到改善，消除因睾丸淤血而造成的损害，以利睾丸的正常发育。方法 对28例30侧(左侧26例，双侧2例)精索静脉曲张与腹壁下静脉进行吻合，通过腹壁下静脉，髂静脉转流，手术在放大镜下应用显微外科技术进行，其中28侧用精索静脉主干，2侧结扎一条属支，用另一条静脉进行吻合。结果 通畅率为100％。术后扩张迂曲静脉团消失，阴囊下坠感消失。术后随访24例，时间为3个月-10年。除1例二次手术证实为一条静脉属支漏扎而复发外，另23例全部治愈。结论 精索静脉曲张转流术效果明显优于结扎术，可减少因睾丸淤血对其造成的进一步损害，且术后复发率低。     

Poisoning in children in Japan

The Japan Poison Information Centre (JPIC) received 31510 inquiries about poisoning in children under 6 years old being exposed to poison in the fiscal year 1995. The most frequently implicated products were tobacco (20%) and the peak age for ingestion of household products was 1 year and younger (83.3%). Especially, the inquiries related to children less than 1 year old were 35.7% of the cases. In contrast, the American Association of Poison Control Centers (AAPCC) data showed that the most common poisonings were due to pharmaceutical products and the inquiries related to children less than 1 year old were only 12.1%. The objective of this report was to find out the poison exposure in children in Japan and to compare the data with that of AAPCC.     

Rotavirus infection in children in Japan

Currently, a high morbidity of rotavirus diarrhea has been seen in children in developed and developing countries. Improvement of the vaccines is necessary in order to reduce the burden of diarrhea caused by rotavirus. A survey of rotavirus infection from diarrheal stool specimens in children of seven regions in Japan was conducted from 1984 to 1999. The present study discusses the survey results and reviews the national and international data of more than 23 papers and congress proceedings about rotavirus infection in Japan. We analyze the prevalence of rotavirus infection in acute diarrheal in- and outpatients, the distribution of rotavirus G-serotypes and surveillance data for seasonality and age groups in Japan. The data indicated that rotavirus is the most important cause of diarrhea in Japan among young children, with the prevalence ranging from approximately 9.7 to 88%. The most common rotavirus strains belonged to serotype G1, specifically since 1993. Serotypes G2, G3 and G4 had also been documented to be predominantly based in the area and year before 1992. However, untypeable rotavirus strains had been found each year, with a prevalence up to 56.7% which suggests that rare serotypes (except G1-4) or new serotypes might exist. Unexpectedly, in Tokyo and Sapporo from 1998 to 1999, G9 was found to be the first most prevailing serotype with a high prevalence of 52.9 and 71.4%, respectively. Despite these data from different geographic areas, the year under investigation was relatively clear in respect to seasonality, with a peak of rotavirus activity in late winter (February) through early spring (March). Age distribution had also characterized that the infection was predominant among children aged 1-2 years of age, although it was also common in children of 2-3 years. In addition, mixed infection with bacteria was documented.