阿糖胞苷代谢关键酶基因在儿童恶性血液肿瘤中的表达

目的通过检测儿童急性白血病(AL)及非霍奇金淋巴瘤(NHL)骨髓细胞内阿糖胞苷(Ara-C)代谢关键酶———脱氧胞苷激酶(DCK)和胞苷脱氨酶(CDA)的基因表达及酶活性水平,探索DCK和CDA表达与临床疗效的关系。方法共计31例患儿,其中初诊27例(ALL20例,AML3例,NHL4例),复发4例(ALL2例,AML、NHL各1例),采集患儿骨髓细胞,采用荧光定量PCR检测细胞内DCK、CDA基因表达,核素液闪法检测细胞内DCK、CDA酶活性,统计分析各组患儿的检测结果。结果 (1)DCK:ALL和NHL患儿DCK mRNA与酶活性水平均明显高于AML患儿(P0.05);初治患儿均明显高于复发患儿(P0.05);(2)CDA:AML和复发患儿的CDA酶活性水平明显高于ALL、NHL和初治患儿(P0.05),但各组病例间的CDA mRNA表达差异无显著性(P0.05)。(3)DCK和CDAmRNA表达与酶活性水平呈高度正相关。结论 AML以及某些复发的血液肿瘤患儿,其总体DCK酶活性及基因表达水平降低,CDA酶活性水平增高。DCK和CDA酶活性可能与儿童恶性血液肿瘤疗效相关。     

急性白血病、恶性淋巴瘤患儿大剂量阿糖胞苷治疗的药代动力学及代谢关键酶基因表达研究

目的 探索大剂量阿糖胞苷(HD-AraC)治疗儿童恶性血液肿瘤的药代动力学,以及代谢关键酶基因表达与临床疗效的关系.方法 应用高效液相色谱法测定HD-AraC治疗时血液和脑脊液中药物浓度;采用RT-PCR法检测3种白血病细胞株和48例急性白血病(AL)患儿骨髓细胞中脱氧胞苷激酶(dCK)和胞苷脱氨酶(CDA)基因表达,通过分析不同类型AL患儿,以及初治和复发患儿dCK和CDA mRNA表达差异,探讨dCK和CDA mRNA表达与疗效的关系.结果 ①HD-AraC治疗时血浆药物浓度可达到常规剂量Ara-C的50倍,脑脊液中药物浓度达到血浆浓度的10%;②不同类型儿童AL,以及初治和复发患儿的dCK mRNA表达强度差异有统计学意义,与临床疗效明显相关;③体外实验发现经Ara-C不同剂量和时间作用后,白血病细胞株的dCK和CDA mRNA表达没有变化.结论 HD-AraC治疗可明显提高血浆和脑脊液中药物浓度,是治疗儿童AL的有效疗法.dCKmRNA表达强弱可能为儿童AL远期疗效的重要影响因素之一.     

急性白血病患儿骨髓血管内皮生长因子与增殖细胞核抗原的表达及其意义

目的探讨增殖细胞核抗原(PCNA)和血管内皮生长因子(VEGF)在儿童急性白血病(AL)中的表达及其意义。方法采用S-P免疫组织化学方法,检测59例AL患儿骨髓细胞PCNA和VEGF表达,比较不同类型白血病、初治组与复发难治组、治疗缓解组与未缓解组间的表达差别。选择同期住院15例非白血病患者正常骨髓作为对照组。结果PCNA、VEGF在AL患儿中表达均明显高于对照组(t=5.59,6.67 P均<0.05);PCNA在初治ALL中表达显著高于ANLL(t=2.681 P<0.05),VEGF表达无差异(t=0.970 P>0.05);初治组与复发难治组、缓解组与未缓解组两者表达均有显著性差异(P均<0.05)。结论PCNA和VEGF在儿童AL中存在高表达,以不同机制参与AL发生、发展,与疾病预后有关。     

急性白血病患儿血浆基质细胞衍生因子-1及其受体CXCR4表达的临床意义

目的探讨儿童急性白血病(AL)血浆基质细胞衍生因子-1(SDF-1)的水平和骨髓细胞表面CXCR4的表达及其临床意义。方法收集50例AL患儿、20例健康儿童和10例非恶性血液病患儿(对照组)。采用ELISA法分别检测AL患儿初诊时、缓解6个月、复发时和对照组儿童外周血浆SDF-1水平。用流式细胞仪检测50例AL患儿初诊时和10例非恶性血液病患儿骨髓细胞表面CXCR4的表达。结果1.AL初诊组和缓解组血浆SDF-1水平明显高于对照组(Pa<0.01),且初诊组高于缓解组(P<0.01);急性淋巴细胞白血病(ALL)组血浆SDF-1水平高于急性髓细胞白血病(AML)组(P<0.01);SDF-1水平在ALL和AML各亚型之间差异无统计学意义;复发的4例患儿,其血浆SDF-1水平在初诊时和复发时均高于缓解时(Pa<0.05);髓外浸润组SDF-1水平与非髓外浸润组比较差异无统计学意义(P>0.05)。2.AL患儿骨髓细胞表面CXCR4的相对荧光强度明显高于对照组(P<0.01);ALL组高于AML组(P<0.01);CXCR4在ALL的L1组与L2组的表达,无统计学差异,但T-ALL组高于B-ALL组(P<0.05...     

nm-23H1基因在儿童白血病细胞表达的研究

目的探讨nm23H1基因在儿童急性白血病(AcuteLeakemia,AL)细胞中的表达及临床意义。方法采用半定量逆转录聚合酶链反应,RTPCR检测67例次AL儿童患者,ALL31例,AML14例,AL(CR)18例,复发4例及10例ITP患儿骨髓细胞nm23H1表达,将nm23H1/GAPDH≥0.5定为(+)。结果儿童ALL、AML中nm23H1基因表达显著高于正常对照组(P<0.001),AML中M4+M5组的nm23H1表达程度较M2+M3组高(P<0.05)。经化疗在CR后儿童AL患者表达显著低于初诊患儿,复发病人再度升高且阳性表达程度高的易复发。nm23H1基因表达程度与外周血白细胞计数及乳酸脱氢酶值呈正相关(r=0.472P<0.01;r=0.403P<0.05)。CD7+患者nm23H1表达高CD7患者(P<0.05)而与HLADR,CD34阳性或阴性表达无显著性。结论nm23H1可能在儿童AL中发挥一定作用,尤其在粒单或单核细胞性白血病中更具重要作用,还与儿童AL的病情活动有关,与白血病细胞处的分化阶段无明显关系。nm23H1基因的表达是儿童AL重要的预后因素。     

黑色素瘤特异性抗原基因在儿童急性白血病中的表达及初步应用

目的探讨急性白血病(AL)儿童骨髓及外周血单个核细胞(MNC)中黑色素瘤特异性抗原(PRAME)基因表达情况,以及用于微小残留病监测的临床意义。方法釆用半定量逆转录聚合酶链反应(RT-PCR)方法检测31例初发、6例复发、10例完全缓解期AL儿童骨髓及外周血PRAME mRNA的表达情况,同时检测10例非血液系统恶性疾病患儿骨髓、5例正常成人外周血中PRAME mRNA的表达情况,分析该基因与疗效、预后之间的关系。结果 37例初发及复发AL病例中15例PRAME mRNA表达阳性(40.5%),其中在急性淋巴细胞白血病(ALL)组、急性髓系白血病(ANLL)组的阳性率分别为37.9%、50.0%,两组比较差异无显著性(P0.05)。在初发组及复发组的表达率分别为38.7%、50.0%,两组比较差异无显著性(P0.05)。10例完全缓解期及15例对照组病例中PRAME mRNA表达均阴性。PRAME基因表达阳性的患儿完全缓解率(CR)显著低于表达阴性的患儿(CR率分别为60.0%,90.99%,P=0.042)。随访1例初诊PRAME基因表达阳性的ALL患儿,经化学治疗达完全缓解后PRAME基因表达转阴。结论 PRAME基因可在AL患儿中呈阳性表达,并可随疾病的缓解情况逐渐降低或转阴。因此,PRAME基因作为儿童AL的一个重要基因标记物,动态监测其表达水平在评估疗效、判断预后、预测复发方面有一定的意义。     

HOXA10基因在儿童急性白血病中的表达及意义

目的探讨急性白血病患儿同源盒(HOX)A10基因的表达及其临床意义。方法选择50例初治急性白血病患儿,其中急性髓系白血病(AML)25例、急性淋巴细胞白血病(ALL)25例,以及13例对照儿童,分离其骨髓单个核细胞,运用逆转录-聚合酶链反应(RT-PCR)检测骨髓单个核细胞HOXA10 mRNA;检测急性白血病患儿外周血白细胞计数(WBC),分析不同类型急性白血病患儿HOXA10基因表达之间的关系。结果对照儿童HOXA10基因的阳性表达率为23.08%,ALL患儿为40%,AML患儿为100%;平均表达灰度比值(ODR)分别为对照儿童0.022±0.001,AML患儿0.373±0.113,ALL患儿0.151±0.006,三组间阳性表达率及表达水平差异均有统计学意义(P<0.01),其中尤以AML患儿最高。HOXA10基因在各型AML中均有表达,其表达水平依次为M1和(或)M2型、M3型、M4和(或)M5型,差异有统计学意义(P<0.01)。WBC≥30×109/L的急性白血病患儿的HOXA10基因阳性表达率显著增高;高危组急性白血病患儿的HOXA10基因的阳性表达率也明显高于中危组和低危组。结论 HOXA10基因的高表达与儿童急性白血病,尤其是与AML明显相关,并且随着AML白血病细胞分化成熟表达逐渐下降;HOXA10基因的阳性表达率与儿童急性白血病危险程度呈正相关,有望成为儿童急性白血病诊断、治疗及判断预后的一个靶点。     

同源盒基因HOXA9在儿童急性白血病中的表达及其临床意义

目的：研究同源盒基因HOXA9在儿童急性白血病（AL）患儿骨髓单个核细胞中的表达,并探讨其临床意义。方法：采用RT-PCR方法检测46例不同时期AL患儿HOXA9 mRNA的表达水平,以15例特发性血小板减少性紫癜（ITP）患儿作为对照。结果：46例AL患儿（52份骨髓标本）HOXA9基因阳性表达率为63%,其中急性髓细胞白血病(AML)组阳性表达率（86%）明显高于急性淋巴细胞白血病（ALL）组（35%）及对照组（13%）（P<0.05）; AML组HOXA9 mRNA表达水平明显高于ALL组及对照组（P<0.05）。HOXA9在各型儿童AML中表达不同,mRNA相对表达水平依次为：M5型＞M4型＞M1和（或）M2型,而在M3型中未检测到表达。HOXA9在AML患儿高危组中的阳性表达水平较高。AML患儿初治组HOXA9基因阳性表达率及mRNA水平明显高于缓解组和对照组（P<0.05）,而缓解组与对照组比较差异无统计学意义;未缓解组HOXA9基因表达显著高于缓解组和对照组（P<0.05）。结论：HOXA9基因高表达与AL的发生相关;AML患儿HOXA9基因表达水平明显高于ALL患儿。HOXA9基因高表达者与白血病危险程度有关,且提示预后不良。因此,HOXA9基因有望成为儿童AL诊断、治疗及判断预后的一个靶点。     

急性白血病患儿mdr1基因定量表达的研究

目的应用新型MGB探针的实时荧光定量聚合酶链反应(FQ-PCR)分析方法,研究mdr1 mRNA在K562细胞系和其耐药细胞系K562/A02细胞及急性白血病(AL)患儿细胞中的表达水平。方法运用Taq Man-MGB探针,以含有目的基因mdr1cDNA的质粒pHaMDR1/A为阳性模板,设立实时FQ-PCR反应体系,研究mdr1 mRNA在不同类型、不同分期AL患儿白血病细胞中的表达;并就AL患儿初治组、难治复发组、完全缓解组分别与正常对照组比较其mdr1 mRNA表达率和表达量,且在AL患儿3组间再作mdr1 mRNA表达率及其表达量比较,数据均作统计学处理。结果初治和完全缓解期AL患儿mdr1 mRNA表达阳性率和表达水平均较正常对照组升高。难治复发组AL患者白血病细胞mdr1 mRNA表达阳性率和表达水平较其他AL各组明显升高;AL完全缓解患者维持期化疗的随访观察中,部分患儿mdr1 mRNA表达量渐升高,尤其是复发AL患儿升高更显著。结论AL患儿化疗耐药的发生与mdr1 mRNA表达有较密切的联系,应用Taq Man-MGB荧光探针进行实时FQ-PCR检测人类mdr1基因在AL细胞中表达,可为AL患儿个体化化疗方案的合理制定、化疗疗效和预后判断及针对性逆转由于mdr1基因表达导致的多药耐药提供有价值的实验室依据。     

儿童急性白血病端粒酶活性与p15基因表达关系的研究(英文)

目的：探讨端粒酶活性与pINK4b(p15)基因表达在儿童急性白血病(AL)发病中的关系。方法：采用改良端粒重复序列PCR扩增和逆转录聚合酶链反应检测27例儿童AL骨髓单个核细胞端粒酶活性和p15基因表达情况,并与9例正常骨髓单个核细胞端粒酶活性及p15基因表达进行比较。结果：初诊时,AL患儿骨髓细胞端粒酶活性(34. 5±37. 0)TPG较对照组(2. 4±2. 2 )TPG明显增高(P<0. 001 ); AL患儿p15基因表达水平(9. 8±16. 2)%, 明显低于对照组(45. 8±16. 9)% (P<0. 001 )。AL患儿骨髓细胞端粒酶活性与p15基因表达水平之间无相关关系(r= 0.01304, P> 0. 05)。结论：端粒酶活化和p15基因表达水平降低与急性髓性白血病发展有关,但两者可能通过不同的机制作用于白血病。     

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.