胆红素诱导海马区神经细胞Fas蛋白过度表达的实验研究

目的探讨胆红素的神经毒性机制.方法制作高胆红素血症动物模型,观察海马区神经细胞的组织学变化,检测海马区神经细胞Fas蛋白表达率及神经细胞凋亡率,并探讨其间相关性.结果高胆红素血症时,海马区神经细胞出现凋亡的组织学改变,神经细胞Fas蛋白表达率在实验组1(T1 G,腹腔注射胆红素0.171μmol/g体重为(19.13±0.25)%,实验组2(T2G,腹腔注射胆红素0.342μmol/g体重)为(33.38±3.45)%,T1G神经细胞凋亡率为(6.13±0.37)%,T2G为(15.44±0.64)%,均较对照组差异有显著性(P＜0.001),二者与脑组织胆红素浓度均呈显著正相关.结论胆红素通过Fas系统的参与,传递凋亡信号,介导胆红素神经毒性,导致神经细胞凋亡.     

高胆红素血症新生大鼠脑组织Tau蛋白的变化与细胞凋亡的关系

目的 观察微管相关蛋白Tau蛋白在高胆红素血症新生大鼠脑组织中的变化与神经细胞凋亡的关系,探讨高胆红素血症中枢神经损伤的发生机制,为高胆红素血症中枢神经系统损伤提供较为特异的早期检测指标.方法 新生7日龄SD大鼠90只.随机分为正常对照组(C组,n=10)和实验组(T组,n=80),T组又根据腹腔注射胆红素剂量的不同分为T1组和 T2组,每组40只.C组大鼠腹腔注射9 g·L-1盐水1.0 mL,T1组腹腔注射胆红素100 μg·g-1,T2组腹腔注射胆红素200 μg·g-1.各实验组根据造模结束后时间点不同(4 h、8 h、12 h、24 h)分为4组,每组10只.观察各组动物不同时间点的神经行为异常如抽搐、翻滚、俯伏、对外界刺激的逃避反应减弱等,取各组动物脑组织常规苏木精-伊红(HE)染色,光镜下观察其脑组织病理改变,免疫组织化学法动态观察其海马区Tau蛋白及p-Tau的表达,脱氧核糖核酸末端转移酶介导的缺口末端标记法检测其海马区神经细胞凋亡率.结果 HE染色可见C组大鼠海马区神经元排列整齐、结构完整,未见胆红素沉积;T组大鼠脑组织内可见不等量的胆红素沉积及神经元细胞数量减少、排列紊乱等.C组大鼠造模结束后未见明显的神经行为异常,T1组大鼠于造模结束后12 h出现翻滚、震颤、俯伏及对外界刺激的逃避反应减弱等表现,T2组大鼠行为异常表现较T1组明显.T组海马区神经细胞出现Tau蛋白表达增加及其过度磷酸化,并表现出时间-剂量依赖性;神经细胞凋亡率随Tau蛋白及p-Tau表达的增加而升高.结论 高胆红素血症时神经细胞发生凋亡增加,Tau蛋白的过度表达及过度磷酸化参与胆红素诱导的神经细胞凋亡,Tau蛋白可作为高胆红素血症早期脑损伤较为特异的检测指标之一,也可将阻止Tau蛋白的过度表达及其磷酸化作为胆红素脑病的治疗靶点之一.     

bFGF对新生大鼠缺氧缺血后海马CA1区神经细胞凋亡的影响

为研究碱性成纤维细胞生长因子 (bFGF)对新生大鼠缺氧缺血 (HI)后海马CA 1区神经细胞凋亡的影响 ,应用新生Wistar大鼠制备缺氧缺血性脑损伤 (HIBD)模型 ,用HE染色、电镜及原位缺口末端标记 (TUNEL)法检测bFGF对HI后海马CA 1区神经细胞凋亡的影响。结果显示HE染色、电镜及TUNEL法均证实HI后海马存在选择性神经细胞凋亡 ,尤以CA 1区为重 ,CA 2和CA 3区病变较轻。TUNEL检测结果 ,bFGF治疗组阳性细胞数 ( 1 5 2 3± 1 4 2 )低于未治疗组 ( 2 5 1 2± 2 0 2 5) ,差异显著 (P <0 0 5)。因此 ,bFGF对HI后海马CA 1区神经细胞确有保护作用。     

bFGF对新生大鼠缺氧缺血后海马CA 1 区神经细胞凋亡的影响

为研究碱性成纤维细胞生长因子(bFGF)对新生大鼠缺氧缺血(HI)后海马CA 1区神经细胞凋亡的影响,应用新生Wistar大鼠制备缺氧缺血性脑损伤(HIBD)模型,用HE染色、电镜及原位缺口末端标记(TUNEL)法检测bFGF对HI后海马CA 1区神经细胞凋亡的影响.结果显示HE染色、电镜及TUNEL法均证实HI后海马存在选择性神经细胞凋亡,尤以CA 1区为重,CA 2和CA 3区病变较轻.TUNEL检测结果,bFGF治疗组阳性细胞数(15.23±14.2)低于未治疗组(25.12±20.25),差异显著(P＜0.05).因此,bFGF对HI后海马CA 1区神经细胞确有保护作用.     

幽门螺杆菌相关性胃炎胃粘膜上皮细胞的增殖凋亡及凋亡相关基因Fas的研究

目的　研究幽门螺杆菌 (HP)感染儿童胃粘膜上皮细胞的增殖、凋亡及凋亡相关基因Fas的变化 ,对幽门螺杆菌的致病机制进行探讨。方法　采用免疫组织化学和Tunel法检测 17例HP阳性小儿慢性胃炎和 19例HP阴性的小儿慢性胃炎胃粘膜上皮细胞增殖、凋亡和凋亡相关基因Fas的变化。结果　HP阳性组的胃粘膜上皮细胞增殖指数为 (9 0 2± 3 82 ) % ,凋亡指数为 (8 46±1 82 ) % ,Fas指数为 (31 2 9± 12 ) % ,HP阴性组胃粘膜上皮细胞增殖指数为 (3 41± 1 33) % ,凋亡指数为 (2 73± 0 85 ) % ,Fas指数为 (11 6 8± 9) %。三者在HP阳性组与HP阴性组之间差异有显著意义 ,与年龄性别无关 ;胃粘膜上皮细胞增殖指数在轻度胃炎为 (3 94± 3 5 1) % ,中度胃炎为 (6 5 3± 4) % ,重度胃炎为 (13 6 5± 7) % ,三者间差异有显著意义 ;凋亡指数在轻度胃炎为 (3 0 8± 1 0 5 ) % ,中度胃炎为 (5 82± 3) % ,重度胃炎为 (17 81± 2 6 3) % ,三者间亦差异有显著意义。细胞的增殖和凋亡在炎症程度间差异有显著意义。结论　HP促进胃粘膜上皮细胞的增殖和凋亡 ;Fas的表达在HP阳性组明显增加 ,提示Fas的过度表达可能是小儿HP相关性胃炎胃上皮细胞凋亡增加的原因之一。     

脑源性神经营养因子及酪氨酸激酶BmRNA在胆红素神经损伤豚鼠皮质及海马表达变化的实验研究

目的探讨新生豚鼠胆红素脑神经损伤时脑源性神经营养因子(BDNF)及其受体酪氨酸激酶B的mRNA(TrkB mRNA)在大脑皮质及海马表达特点。方法取生后2～5 d的豚鼠60只,随机分为3组,每组各20只。T1组腹腔注射晶体胆红素100μg/g;T2组腹腔注射胆红素200μg/g;C组为对照组,腹腔注射生理盐水。分别在注射后4、8 h各处死10只。作脑组织切片,电镜、光镜观察病理改变;并采用免疫组化、原位杂交和图像分析,观察不同时间点BDNF、TrkB mRNA在皮质及海马表达变化。结果胆红素脑神经元损伤模型成功建立。在腹腔注射胆红素4 h时,皮质及海马的BDNF阳性细胞数降低,而TrkB mRNA阳性细胞数增加,与对照组比较差异均有统计学意义(P<0.05)。随时间延长至8 h时,皮质及海马的BDNF和TrkB mRNA阳性细胞数均较4 h时增加,差异有统计学意义(P均<0.05)。T2组与T1组比较,皮质和海马的BDNF和TrkB mRNA的阳性细胞数变化更明显。结论胆红素脑神经元损伤时,皮质和海马的BDNF、TrkB mRNA表达变化可能在抑制神经元凋亡和神经元修复中发挥重要作用,有利于减轻神经元损伤,以及神经元的修复和再生,这可能是胆红素脑神经元损伤时机体的自我保护机制之一。     

N-乙酰-L-半胱氨酸对缺氧缺血新生大鼠海马CA1区神经元凋亡影响的研究

探讨抗氧化剂N-乙酰-L-半胱氨酸(NAC)对缺氧缺血新生大鼠海马CA1区神经元凋亡的影响.将70只7日龄Wistar大鼠随机分成3组,①假手术组(n=10)仅作颈正中切口,不作颈总动脉结扎;②观察组(NAC组n=30,HIBD)后即刻腹腔内注射NAC 200 ug/只;③对照组(生理盐水组n=30),HIBD后即刻腹腔注射等体积的生理盐水.假手术组于手术后即刻,观察组、对照组于处置后48小时断头取脑,进行HE和Tunel染色光镜下检测脑细胞凋亡数.结果对照组大鼠海马CA1区可见典型的凋亡细胞,表现为细胞固缩、胞浆深染、核浓缩、碎片、核浆分布不清,有凋亡小体形成;NAC组上述凋亡细胞明显减少;Tunel染色对照组阳性细胞数与NAC组比较差异有明显的统计学意义(P＜0.05).结论NAC对HIBD后海马CA1区神经细胞凋亡有明显的抑制作用.     

L-肌肽对高热惊厥幼鼠神经细胞凋亡的影响

目的 探讨L-肌肽对幼年大鼠实验性高热惊厥后神经细胞凋亡的影响.方法 40只15日龄SD大鼠采用随机数字表法分为L-肌肽干预组(n=30)和惊厥对照组(n=10).采用热水浴法诱导干预组和惊厥对照组大鼠实验性FS发作10次;干预组又随机分为E、G、H组,分别在每次惊厥发作后30、60、120min腹腔注射L-肌肽250mg/kg;惊厥对照组仅诱发癫癎,不给予干预,末次惊厥后12 h处死大鼠,并采用原位末端脱氧核苷酸生物素标记法分别测定幼鼠海码结构及大脑皮层神经元凋亡情况,透射电镜观察其凋亡细胞超微形态学改变.结果 惊厥对照组神经细胞凋亡计数为25.37±1.95,E组为l2.364±1.13,G组为17.854±2.04,H组为22.69±2.69.惊厥对照组神经细胞凋亡明显高于干预组(F=10.75 P＜0.01);给予L-肌肽腹腔注射后E组和G组神经细胞凋亡明显低于惊厥对照组(t=18.26,8.45 Pa＜0.01);但H组神经细胞凋亡与惊厥对照组无明显差异(t=2.55 P＞0.05).透射电镜观察可见,惊厥对照组和H组大鼠海马CA1区、齿状回神经元损伤明显高于E组.结论 早期给予L-肌肽具有减轻反复FS引发的幼鼠神经细胞凋亡,具有一定的保护神经细胞作用.     

N-乙酰-L-半胱氨酸对缺氧缺血新生大鼠海马CA1区神经元凋亡影响的研究

探讨抗氧化剂N-乙酰-L-半胱氨酸(NAC)对缺氧缺血新生大鼠海马CAl区神经元凋亡的影响。将70只7日龄Wistar大鼠随机分成3组,①假手术组:(n=10)仅作颈正中切口,不作颈总动脉结扎;②观察组(NAC组n=30,HIBD)后即刻腹腔内注射NAC 200ug/只;③对照组(生理盐水组n=30),HIBD后即刻腹腔注射等体积的生理盐水。假手术组于手术后即刻,观察组、对照组于处置后48小时断头取脑,进行HE和Tunel染色光镜下检测脑细胞凋亡数。结果:对照组大风海马CAl区可见典型的凋亡细胞,表现为细胞固缩、胞浆深染、核浓缩、碎片、核浆分布不清,有凋亡小体形成;NAC组上述凋亡细胞明显减少;Tunel染色对照组阳性细胞数与NAC组比较差异有明显的统计学意义(P<0.05)。结论:NAC对HIBD后海马CAl区神经细胞凋亡有明显的抑制作用。     

兴奋性氨基酸受体拮抗剂对胆红素神经毒性的影响

目的　探讨兴奋性氨基酸受体拮抗剂磷酸甲基谷氨酰氨酸 (GAPA)对胆红素神经毒性的影响。方法　在制作胆红素脑病动物模型基础上予GAPA干预 ,观察对照组、模型组、模型干预组新生豚鼠 (每组 10只 )干预后 4、8h脑组织超微结构、脑组织ATP含量与含水量。结果　模型组脑组织ATP含量在 4、8h分别为 (2 .7± 0 .7) μmol/g与 (2 3± 0 7) μmol/g,显著低于对照组 (4 3± 0 6 )μmol/g与 (4 1± 0 6 ) μmol/g ;GAPA干预组脑组织ATP含量在干预后 4、8h分别为 (2 6± 0 9) μmol/g与 (2 5± 0 8) μmol/g,显著低于对昭组 ,但与模型组比较 ,差异无显著性。胆红素脑病脑组织含水量显著增高 ,GAPA显著减轻胆红素毒性脑水肿 ,脑组织超微结构变化亦与此相符。结论　沉积于脑组织胆红素可抑制神经元能量代谢 ,致脑细胞水肿 ;兴奋性氨基酸受体拮抗剂GAPA可减轻脑水肿 ,但不影响能量代谢变化 ,其作用环节介于能量代谢变化与脑水肿之间。     

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.     

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   

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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.     

A profile of respiratory symptoms in urban and rural South Australian school children

This report describes the cross-sectional analyses of data from the first year of a longitudinal study using questionnaire and respiratory function data over a 5 year period from a sample of rural South Australian school children. The cumulative or lifetime prevalences of respiratory symptoms were estimated in 825 rural and 1261 urban school children aged between 5 and 15 years in order to determine if the prevalence rates differed between rural and urban school children. The study found the overall cumulative prevalence of asthma and/or wheezy breathing (AWB) to be 24.1% in the rural school children compared to 27.6% in the urban school children. Most children developed AWB symptoms before the age of 7 years, with 20% reporting moderately severe symptoms and 10% having more than one attack per fortnight. The cumulative prevalence of bronchitis, loose/rattly cough (BLRC) differed significantly between the rural school children (34.1%) and urban school children (47.9%). The BLRC symptoms preceded the development of AWB in many cases. Urban school children also reported a higher prevalence of atopic conditions.     

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.     

Hauttemperaturen verschiedener Körperoberflächenareale des Rumpfes bei Säuglingen

Summary In two groups of infants (3–53 weeks old) skin temperatures were controlled in different areas of the trunk—i.e.: regions of sternum, lungs, heart, liver, spleen, kidneys—at different room-temperatures (group I: 21–25°C; group II: 29–32°C). Rectal temperatures of some probands in both groups also had been controlled simultaneously. A definite change in the reaction to heat was proofed in different periods of the first year of life. In higher environmental temperatures the skin temperature was almost constant at every controll-point of the skin, even in older infants. In lower environmental temperatures the skin temperatures lowered continuously with age till 7. to 9. moth. From 10. to 12. month the lowering of skin temperature discontinued. The rectal temperatures were relatively constant in all infants. Only in infants from 7. to 12. month, whose skin temperatures were controlled in lower as well as in higher environmental temperatures, a tendency to higher rectal temperatures was proofed in warmer environmental temperatures.The significance of these results is discussed.

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Untersuchungen mit Unterstützung durch die Deutsche Forschungsgemeinschaft.