儿童过敏性紫癜遗传学机制研究进展

对儿童过敏性紫癜临床表现特点及流行病学的深入研究揭示遗传因素与本病发病及病理过程密切相关.近年来分子生物学的研究显示,与IgA1异常糖基化密切相关的C1GALT1基因及IL基因、血管舒缩和内皮功能调节基因、血管紧张素转化酶基因、血管紧张素原基因、MEFV基因等与儿童过敏性紫癜密切相关.该文就近年来与过敏性紫癜发病相关的遗传学机制研究进展作一综述.     

儿童紫癜性肾炎的诊治进展

过敏性紫癜是儿童时期以小血管炎为主要病变的全身性血管变态反应性疾病。紫癜性肾炎是过敏性紫癜最常见的继发性肾脏疾病,临床上在过敏性紫癜病程中(多数6个月内)出现血尿和(或)蛋白尿即可诊断。其临床表现轻重不一,发病率呈逐年升高趋势,发病机制可能与感染、过敏、免疫异常、免疫损伤等有关。提高对儿童紫癜性肾炎的认识,早期诊断、早期治疗对患儿预后具有很大的影响。     

过敏性紫癜相关基因多态性研究进展

许多研究显示,疾病的发生、发展以及治疗效果与基因的多态性有关.近年来一些研究结果显示,某些基因多态性与过敏性紫癜及过敏性紫癜.肾炎的发病机制、易感性、病理进展及预后明显相关,如肾素-血管紧张素系统基因、人类白细胞抗原基因、细胞因子基因、PAX2基因、一氧化氮合酶基因等.该文就过敏性紫癜相关基因多态性的研究进展作一综述.     

过敏性紫癜糖皮质激素受体的研究

目的通过对外周血淋巴细胞糖皮质激素受体(GCR)测定,探讨GCR与儿童过敏性紫癜发病及预后的关系.方法采用完整细胞放射配基结合分析法测定35例过敏性紫癜初始发病儿童的外周血淋巴细胞GCR.结果过敏性紫癜儿童外周血淋巴细胞GCR为3060±2153结合位点/细胞,低于正常儿童外周血淋巴细胞GCR(5210±1639结合位点/细胞)(t=7.4P＜0.001).18例随访1a以上.复发5例,复发者GCR水平低于未复发者.复发者中1例初始病程长达4个月,1a中复发3次,其GCR仅为127结合位点/细胞.14例并紫癜性肾炎与无肾损害患儿GCR水平无显著差别.结论过敏性紫癜儿童淋巴细胞GCR水平下降,可能与本病的免疫病损发生有关;GCR水平明显下降可能预示疾病预后差,易复发.     

过敏性紫癜患儿血清白三烯B_4白介素-5的测定及其临床意义

目的：观察过敏性紫癜患儿血清白介素-5(IL-5)和白三烯B4(LTB4)在不同发病阶段的浓度变化,以探讨IL-5和LTB4在过敏性紫癜发病机制中的作用。方法：采集31例过敏性紫癜患儿急性期和恢复早期血清,以及27例健康儿童血清,应用酶联免疫吸附试验检测血清中IL-5,LTB4和C反应蛋白(CRP)含量。结果：过敏性紫癜患儿的急性期血清IL-5,LTB4和CRP含量明显高于恢复早期(P<0.01),恢复早期血清IL-5,LTB4和CRP含量又显著高于正常组儿童(P<0.01)。IL-5和LTB4变化与CRP呈正相关。结论：过敏性紫癜患儿的急性期血清IL-5和LTB含量升高,恢复早期有所下降,提示IL-5和LTB参与了过敏性紫癜的发病过程。     

儿童时期的紫癜性肾炎

过敏性紫癜所引起的肾损害,简称为紫癜性肾炎,是儿童时期重要的肾小球疾病之一。也是具有潜在危险的肾炎之一。根据Habib等人报告此病占儿童时期肾小球疾病的7%,在作者收住院的143名终末期肾功能衰竭的患儿中紫癜性肾炎有11例(7%)。发病情况紫癜性肾炎的发病率其说不一,约占过敏性紫癜的20～100%或25～50%,发病率的高低悬殊与查尿方法和次数以及过敏性紫癜追踪时间的长短有关。尿常规检查完全正常的患儿肾活体组织检查即可异常,因此肾     

儿童过敏性紫癜临床特征分析(附184例报道)

目的　了解过敏性紫癜儿童的临床特征。方法　回顾性分析过敏性紫癜患儿 184例 ,对其临床表现及特征进行分析。结果　①发病年龄均 >2岁 ,平均发病年龄 (7.8± 2 .6 )岁 ;6 7.4 %患儿于秋冬季节发病 ;6 2 .5 %患儿有明确诱因 ,以上呼吸道感染为主。②所有病人均有典型皮肤紫癜 ,分布于下肢 (10 0 % )、臀部(47.3% )、上肢 (17.4 % )等。 89.1%患儿以皮肤紫癜首发 ,少数以胃肠道及关节症状为首发症状后 2周内出疹 ,先出现肾脏损害而后出疹者罕见。胃肠道及关节症状发生率分别为 6 0 .9%和 4 4 .6 %。紫癜性肾炎发生率为 5 2 .2 % ,临床上主要表现为血尿和 (或 )蛋白尿 (6 8.8% ) ,病理改变主要为Ⅰ～Ⅲ级 (85 .2 % )。③ 4 4 .0 %病人血沉增快 ,2 4 .1%ASO增高 ;6 3.7%病人IgA增高 ,IgG ,IgM及补体绝大多数正常。 结论　过敏性紫癜为儿童常见病 ,且有其本身临床特征及发病规律     

儿童过敏性紫癜与幽门螺杆菌感染关系初步探讨

过敏性紫癜(HSP)为儿童时期常见病,占小儿风湿性疾病首位。其临床表现多样,其中约60％出现消化道症状,以腹痛最多见。发病诱因以感染占第一位,可为链球菌、支原体、EB病毒及微小病毒B19感染,而幽门螺杆菌(H．pylori)感染诱发儿童过敏性紫癜国内尚未见报道。本研究通过对过敏性紫癜伴腹痛患儿行胃镜检查及H．pylori检测,探讨H．pylori感染与过敏性紫癜发病及复发的关系。     

儿童脑积水发病机制的研究进展

脑积水是一种脑脊液生理代谢过程紊乱所致的常见疾病,其损伤机制为脑室系统异常扩张并对周围脑组织造成损害.儿童脑积水随发病年龄和发病原因的不同可表现出个体化的临床症状,同时此类疾病容易造成儿童脑发育迟滞,因此了解疾病的发生机制及病因、早期诊断以提出针对性的治疗策略尤为重要.该文主要对儿童脑积水病理生理、病因及特征性临床表现的研究进行综述.     

过敏性紫癜患儿血清细胞因子的检测及意义

目的 研究肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6和IL-8在过敏性紫癜和紫癜性肾炎发病中的作用.方法 采用双抗体夹心ELISA法检测过敏性紫癜患儿血清TNF-α、IL-6和IL-8的水平.结果 过敏性紫癜急性发病期血清TNF-α、IL-6和IL-8水平较对照组明显增高(P<0.01);在恢复期,TNF-α、IL-6和IL-8则明显下降;紫癜性肾炎时TNF-α、IL-6、IL-8水平较过敏性紫癜时有所增高(P<0.05).结论 TNF-α、IL-6和IL-8在过敏性紫癜和紫癜性肾炎的发病中发挥了一定的作用.     

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.