血管舒张反应关系研究

目的 探讨体位性心动过速综合征（POTS）儿童血浆硫化氢（H2S）含量和血流介导血管舒张反应（FMD）的变化及二者之间的关系。方法 收集自2013年1月至7月在北京大学第一医院儿科门诊或住院部经直立试验或直立倾斜试验确诊为POTS的儿童36例,（11±3）岁;以18例正常儿童为对照组,（11±4）岁。POTS的诊断依据临床表现及直立试验或直立倾斜试验,血浆H2S含量测定使用敏感硫电极方法,FMD的测定使用彩色多普勒超声检测方法。结果 两组儿童在年龄、性别分布、身高、体重、体重指数、平均动脉压方面差异无统计学意义（P＞0.05）,POTS组儿童平卧位心率明显高于正常对照,分别为（88±15）次/min和（77±11）次/min（P = 0.006）。血浆H2S含量在POTS组明显高于正常对照［（30.25±11.64） μmol/L和（17.58±1.74） μmol/L, P＜0.01］, FMD水平在POTS组明显高于正常对照［（9.87±1.63）%和（5.92±2.14）%, P＜0.001］,血浆H2S含量与FMD水平呈明显正相关,相关系数为0.565（P＜0.001）。结论 POTS儿童血浆H2S含量和FMD水平明显升高,提示POTS儿童中异常的血管舒张反应。     

儿童一过性意识丧失基础疾病谱分析

目的 通过多中心、大样本的临床研究,分析儿童一过性意识丧失（transient loss of consciousness,TLOC）的基础疾病谱.方法 研究对象为1999年8月至2013年4月在北京、湖南、湖北、上海四地儿科晕厥门诊就诊或住院的1203例TLOC患儿,其中男559例,女644例,年龄2-18岁,平均（11.5±3.2）岁,从病因学角度分析,得出儿童晕厥的基础疾病谱.结果 1203例TLOC患儿中,1125例为晕厥患儿,占所有患儿的93.5％,78例为非晕厥患儿.在晕厥患儿中,血管迷走性晕厥（vasovagal syncope,VVS）最常见,共409例,占34.1％,其中VVS-血管抑制型（VVS-vasoinhibitory,VVS-Ⅵ）234例,是VVS最常见的血流动力学类型,其次为体位性心动过速综合征（postural orthostatic tachycardia syncope,rOTS）,共346例（28.8％）,直立性高血压（orthostatic hypertension,OHT）24例,占2.0％.结论 晕厥是引起儿童TLOC最常见的原因,而VVS是引起晕厥最常见的病因,VVS-血管抑制型是VVS最常见的血流动力学类型,OHT可以导致儿童晕厥.     

不明原因晕厥患儿直立倾斜试验中血流动力学反应模式及意义

目的　探讨不明原因晕厥患儿在直立倾斜试验中血流动力学反应模式及构成比例。方法　对 2 0 0 1年1月至 2 0 0 3年 12月北京大学第一医院儿科收治的 90例不明原因晕厥患儿在安静环境下进行直立倾斜试验或硝酸甘油激发的直立倾斜试验 ,持续监测患儿心率和血压变化。结果　 90例不明原因晕厥患儿直立倾斜试验中 ,经典的血管迷走性反应者 4 9例 ( 5 4 4 % ) ,其中血管抑制型 33例 ( 36 7% ) ,心脏抑制型 6例 ( 6 7% ) ,混合型 10例( 11 1% )。正常直立反应者 12例 ( 13 3% ) ,体位性心动过速反应者 2 8例 ( 31 1% ) ,直立性低血压反应者 1例( 1 1% ) ,没有发现自主神经反应障碍型及心脏变时功能障碍型。结论　不明原因晕厥患儿在直立倾斜试验中以经典的血管迷走性反应为主 ,其次为体位性心动过速综合征的反应 ,还可能出现体位性低血压等其他的异常血流动力学变化     

直立倾斜试验在儿童血管迷走性晕厥中的诊断价值

目的：探讨直立倾斜试验儿童血管迷走性晕厥的诊断价值。方法：对24例不明原因晕厥的患儿进行基础直立倾斜试验，并以12名正常儿童作对照，在倾斜过程中动态观察心电图、血压、心率，并进行分析。结果：24例晕厥患儿中，基础直立倾斜试验阳性16例，而对照组为0.诊断敏感度为67%,特异度为100%,诊断价值为78%.16例阳性反应中，心脏抑制型反应3例（19%），表现为心动过缓，血压无变化；血管抑制型反应9例（56%），表现为血压下降，心率加快；混合型反应4例（25%），表现为心率、血压均有明显下降。结论：基础直立倾斜试验可作为儿童血管迷走性晕厥的一种重要诊断方法。     

基于生物标记分子的儿童血管迷走性晕厥与体位性心动过速综合征临床鉴别诊断

血管迷走性晕厥(VVS)与体位性心动过速综合征(POTS)是儿童及青少年自主神经介导性晕厥中最为常见的两种类型,临床有时难以区分。明确诊断需进行直立倾斜试验,随着转化医学的开展,硫化氢(H2S)及血清铁等内源性生物标记物在VVS及POTS的诊断预测和个体化治疗方面已取得了重要的临床价值。     

儿童直立倾斜试验血流动力学变化与身高、体重及体质量指数的关系

目的 探讨儿童直立倾斜试验（HUTT）血流动力学变化与身高、体重及体质量指数（BMI）的关系.方法 收集2000年1月至2012年8月在中南大学湘雅二医院儿童晕厥专科 门诊就诊或住院的不明原因晕厥、头痛、头晕、胸闷、叹气等儿童1 906例,男964例,女942例,年龄2.00 ～ 17.92岁,平均10.84±2.97）岁.测量身高、体重,计算BMI.在取得受试者或监护人书面知情同意后,进行HUTT.根据HUTT结果及反应类犁分HUTT阴性组、体位性心动过速综合征（POTS）组、血管迷走性晕厥（VVS）血管抑制型组、VVS心脏抑制型组、VVS混合型组.结果 与HUTT阴性组相比,年龄在POTS组、VVS血管抑制型组、VVS混合型组较大（P＜0.05）,身高、体重、体表面积在POTS组、VVS血管抑制型组、VVS混合型组增加（P＜0.01）.与POTS组相比,体重、体表面积在VVS血管抑制型组、VVS混合型组降低（P＜0.05）,VVS心脏抑制型组与其他各组比较差异未见统计学意义（P＞0.05）.结论 儿童HUTT血流动力学变化与身高、体重及BMI存在一定关系.     

儿童青少年自主神经介导性晕厥的临床诊治

自主神经介导性晕厥是儿童晕厥中最常见的类型,是一种功能性心血管疾病,包括血管迷走性晕厥(vasovagal syncope,VVS)、体位性心动过速综合征(postural tachycardia syndrome,POTS)、直立性低血压(orthostatic hypotension,OH)、直立性高血压(orth...     

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目的应用多普勒超声显像法探讨血管迷走性晕厥(VVS)儿童的血管内皮功能。方法研究对象共20例,均为2002年1月至2003年12月在北京大学第一医院儿科就诊儿童,分为VVS组(n=10)及非VVS对照组(n=10),对10例经直立倾斜试验确诊的血管迷走性晕厥儿童,应用多普勒超声测定肱动脉的血流介导的血管舒张反应,并与10例经直立倾斜试验除外VVS的对照组儿童进行比较。结果两组患儿的年龄、性别、身高、体重、基础血压及基础肱动脉血管内径均无显著性差异,但血管迷走性晕厥儿童的血管内皮依赖性舒张功能较对照组显著增强[(11.93±4.46)%vs(8.46±2.18)%,P<0.05]。结论血管内皮依赖性舒张功能增强可能是儿童血管迷走性晕厥发生机制之一。     

基础状态下空腹血糖与儿童直立倾斜试验结果的关系

目的 探讨基础状态下空腹血糖与儿童直立倾斜试验（head-up tilt table test,HUTT）结果的关系.方法 收集2012年9月至2013年2月在我院儿童晕厥专科门诊就诊或住院的不明原因晕厥、头痛、头晕、胸闷、叹气等儿童157例,男86例,女71例,年龄3 ～18岁,平均（11.34±3.29）岁.在排除器质性心脑血管疾病及其他原因所致上述症状,取得受试者或监护人书面知情同意后,进行HUTT.HUTT前监测患儿基础状态下空腹微量血血糖.结果 （1） HUTT阴性组（n=63）与HUTT阳性组（n=94）之间空腹血糖差异未见统计学意义[（5.40 ±0.52） mmol/L vs （5.35±0.61） mmol/L,t=-0.590,P＞0.05].（2） 94例HUTT阳性儿童中心脏抑制型血管迷走性晕厥仅l例未纳入统计,血管抑制型血管迷走性晕厥（n=67）、混合型血管迷走性晕厥（n=10）及体位性心动过速综合征（n=16）之间空腹血糖未见组间差异[（5.34±0.54）mmol/L vs （5.07 ±0.64） mmol/L vs （5.49 ±0.81） mmol/L,P均＞0.05].（3） 67例血管抑制型血管迷走性晕厥儿童中基础直立倾斜试验（n=16）与舌下含化硝酸甘油倾斜试验（n=51）两种诱发方式的空腹血糖差异未见统计学意义[（5.32±0.54） mmol/L vs（5.35 ±0.55） mmol/L,t=0.166,P＞0.05].（4）空腹血糖＜5.5 mmol/L与≥5.5 mmol/L两组的HUTT阴性率[37.63％（35/93） vs43.75％（28/64）]和HUTT阳性率[62.37％ （58/93） vs 56.25％ （36/64）]差异未见统计学意义（x2 =0.585,P＞0.05）.结论 空腹血糖对儿童HUTT结果没有预测价值.     

儿童血管迷走性晕厥诊治进展

血管迷走性晕厥(vasovagal syncope,VVS)是儿童自主神经介导性晕厥(neuromediated syncope,NMS)中最常见的一种类型[1],占儿童晕厥的40%~50%以上[1-2],严重影响患儿的生活和学习[3-4]。1997年,北京大学第一医院儿科首次发现我国儿童中存在VVS,并将基础直立倾斜试验用     

Allergic factors associated with the development of asthma and the influence of cetirizine in a double-blind, randomised, placebo-controlled trial: First results of ETA®

There is a common progression known as the allergic march from atopic dermatitis to allergic asthma. Cetirizine has several antiallergic properties that suggest a potential effect on the development of airway inflammation and asthma in infants with atopic dermatitis. Methods. Over a two year period, 817 infants aged one to two years who suffered from atopic dermatitis and with a history of atopic disease in a parent or sibling were included in the ETAC^® (Early Treatment of the Atopic Child) trial, a multi-country, double-blind, randomised, placebo-controlled trial. The infants were treated for 18 months with either cetirizine (0.25mg/ kg b.i.d.) or placebo. The number of infants who developed asthma was compared between the two groups. Clinical and biological assessments including analysis of total and specific IgE antibodies were performed. Results. In the placebo group, the relative risk (RR) for developing asthma was elevated in patients with a raised level of total IgE (≥ 30 kU/I) or specific IgE (≥ 0.35 kUA/I) for grass pollen, house dust mite or cat dander (RR between 1.4 and 1.7). Compared to placebo, cetirizine significantly reduced the incidence of asthma for patients sensitised to grass pollen (RR = 0.5) or to house dust mite (RR = 0.6). However, in the population that included all infants with normal and elevated total or specific IgE (intention-to-treat - ITT), there was no difference between the numbers of infants developing asthma while receiving cetirizine or placebo. The adverse events profile was similar in the two treatment groups. Discussion. Raised total IgE level and raised specific IgE levels to grass pollen, house dust mite or cat dander were predictive of subsequent asthma. Cetirizine halved the number of patients developing asthma in the subgroups sensitised to grass pollen or house dust mite (i.e. 20% of the study population). In view of the proven safety of the drug, we propose this treatment as a primary pharmacological intervention strategy to prevent the development of asthma in specifically sensitised infants with atopic dermatitis.     

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孤独症谱系障碍(autistic-spectrum disorders,ASDs)近年来患病率逐年攀升至1%左右,其症状往往伴随终生,成为严重威胁儿童健康和发展的神经发育性疾患;注意缺陷多动障碍(attention deficit hyperactivity disorder,ADHD)是儿童期最常见的精神障碍,国内报道患病率为4.13%～5.83%,其症状可延续至青少年期,甚至到成年期[1]。这两类精神障碍在成年期的临床表现、共患病、治疗策略和预后与儿童期有哪些不同呢?本文通过回顾相     

EXCITING NEW TREATMENT APPROACHES FOR PATHYPHYSIOLOGIC MECHANISMS OF SICKLE CELL DISEASE

During the past several decades, our understanding of the complex pathophysiology of vasoocclusion associated with sickle cell disease has improved greatly. Interaction of genes, hemoglobin molecules, red cell membrane and metabolic changes, cell-cell interactions and cell-plasma interactions, red cell adhesion to vascular endothelium, activation of coagulation, and vascular reactivity play a role in vaso occlusion. Penicillin prophylaxis of pneumococcal infections and appropriate use of blood transfusions and other supportive measures improved survival of sickle cell patients. Hydroxyurea made a major impact on sickle cell therapy when it was shown to decrease acute painful episodes, acute chest syndrome, and the need for blood transfusion in adults. Significant experience in the use of hydroxyurea has been accumulated in older children. The benefits and risks of hydroxyurea for younger children and long-term risks in all patients will be evaluated in future investigations. Other promising therapies include butyrate compounds, clotrimazole, magnesium supplementation, poloxamer 188, antiadhesion agents, anticoagulant approaches, and nitric oxide. Hemopoietic transplantation remains the only curative therapy. However, several transgenic mouse models are available for studies of gene therapy or other treatment approaches on biochemical, cellular, and pathologic effects of mutant genes.     

Infiltrations of Epstein-Barr virus-carrying cells in granular lymphocyte-proliferative disorders corresponding to chronic active Epstein-Barr virus infection

A 21-year-old man with granular lymphocyte-proliferative disorders (GLPD) associated with chronic active Epstein-Barr virus (EBV) infection is described. Chromosomal analyses revealed several clonal abnormalities and two of them were mainly repetitious. High copy numbers of monoclonal EBV genome were also detected in the proliferative large granular lymphocytes (LGLs), indicating the monoclonal expansion of EBV-infected LGLs. The patient had an indolent course for several years, and there was no evidence of infiltrations of his bone marrow until the end stage. At autopsy, microscopic studies revealed marked infiltrations of LGL in the liver and spleen, and the infiltrating cells were NK-cell immunophenotype. The infiltrated LGLs showed latency I.     

LUTEINIZING HORMONE RECEPTOR MUTATIONS IN DISORDERS OF SEXUAL DEVELOPMENT AND CANCER

Human male sexual development is regulated by chorionic gonadotropin (CG) and luteinizing hormone (LH). Aberrant sexual development caused by both activating and inactivating mutations of the human luteinizing hormone receptor (LHR) have been described. All known activating mutations of the LHR are missense mutations caused by single base substitution. The most common activating mutation is the replacement of Asp-578 by Gly due to the substitution of A by G at nucleotide position 1733. All activating mutations are present in exon 11 which encodes the transmembrane domain of the receptor. Constitutive activity of the LHR causes LH releasing hormone-independent precocious puberty in boys and the autosomal dominant disorder familial male-limited precocious puberty (FMPP). Both germline and somatic activating mutations of the LHR have been found in patients with testicular tumors. Activating mutations have no effect on females. The molecular genetics of the inactivating mutations of the LHR are more variable and include single base substitution, partial gene deletion, and insertion. These mutations are not localized and are present in both the extracellular and transmembrane domain of the receptor. Inactivation of the LHR gives rise to the autosomal recessive disorder Leydig cell hypoplasia (LCH) and male hypogonadism or male pseudohermaphroditism. Severity of the clinical phenotype in LCH patients correlates with the amount of residual activity of the mutated receptor. Females are less affected by inactivating mutation of the LHR. Symptoms caused by homozygous inactivating mutation of the LHR include polycystic ovaries and primary amenorrhea.     

Resurgence of measles in Singapore: profile of hospital cases

OBJECTIVE: To ascertain the profile of cases of measles seen at a general hospital during a recent outbreak that occurred despite a measles vaccination program. METHODOLOGY: A retrospective study from January 1991 to March 1998. All patients with measles (ICD code 055. 9) seen at the emergency unit or as inpatients were included. RESULTS: There were 87 cases identified. The diagnosis was clinical in all and proven serologically in 71%. Eighty-five per cent of the cases occurred between January 1997 and March 1998. There was a bi-modal age distribution with peaks in the very young (相似文献   

Personality profiles and heart rate variability (vagal tone) in children with recurrent abdominal pain

The aim of the study was to explore psychological factors and autonomic activity in children with recurrent abdominal pain and to compare them with those in a control group of healthy children. The Personality Inventory for Children was used for assessment of developmental, emotional and psychosocial factors in 25 children with recurrent abdominal pain (age, 7-15 y). Parasympathetic and sympathetic functions in these children and in 23 healthy control subjects (age, 7-13 y) were also investigated, non-invasively using a computerized polygraph. Vagal tone (parasympathetic function) was indexed by calculation of respiratory sinus arrhythmia in beats/min. Skin conductance (sympathetic function) was recorded by the constant current method. On the Personality Inventory for Children, 16 patients had high scores on somatic concern. Several patients had scores in the clinical range for depression, withdrawal and anxiety, but the mean scores for these personality profile scales were well within the normal range of healthy children. Interestingly, there was a spike on the L (Lie)-scale for most of the patients and 15 patients had scores above or close to the clinical cut-off value. As compared with the scores in healthy children, vagal tone and sympathetic tone were normal. Conclusion: Many children with recurrent abdominal pain have scores in the clinical range for depression, withdrawal, anxiety and L-scale indicating coping problems, denial and a trend towards somatic concern that may contribute to the evolution of abdominal pain. Autonomic nerve activity was not disturbed in these children.     

Overcoming surfactant inhibition with polymers

Inhibition of the function of pulmonary surfactant in the alveolar space is an important element of the pathophysiology of many lung diseases, including meconium aspiration syndrome, pneumonia and acute respiratory distress syndrome. The known mechanisms by which surfactant dysfunction occurs are (a) competitive inhibition of phospholipid entry into the surface monolayer (e.g. by plasma proteins), and (b) infiltration and destabilization of the surface film by extraneous lipids (e.g. meconium-derived free fatty acids). Recent data suggest that addition of non-ionic polymers such as dextran and polyethylene glycol to surfactant mixtures may significantly improve resistance to inhibition. Polymers have been found to neutralize the effects of several different inhibitors, and can produce near-complete restoration of surfactant function. The anti-inhibitory properties of polymers, and their possible role as an adjunct to surfactant therapy, deserve further exploration.     

Understanding infant formula

The World Health organisation recommends breast feeding infants for the first six months of life. When this breast feeding does not occur either through parental choice or medical need, infant formulas will be required. There is a bewildering array of formulas on the UK market for many different requirements. When faced with an unsettled infant many parents (and healthcare professionals) will experiment with the infant formula available and then attend the paediatric clinic looking for help and advice. It is therefore essential that paediatricians understand what milks are available and what the key differences between different products are. This review attempts to provide a simple guide through many of the formulations currently available in the UK; and offers advice for the dietary management of the child with extra calorie requirements, infants with cow's milk protein allergy, gastro oesophageal reflux disease, apparent unresolved hunger and infantile colic. Whatever the underlying condition, there is likely to be an infant formula that is suitable in this generation of ever expanding formulations.