Cardiovascular indices of physiological arousal in boys with fragile X syndrome

In this study, the relationship between physiological arousal, as indexed by heart rate variability, was examined in boys with fragile X syndrome (FXS) and typically developing boys matched on chronological age. In addition, the relationship of heart activity to clinical and molecular factors in the group of boys with FXS was examined. Results suggest that boys with FXS have higher levels of heart activity during the passive phases, as reflected in shorter heart periods. This high level of heart activity appears to be due to increased sympathetic activity and reduced parasympathetic activity. Boys with FXS did not display the expected patterns of heart activity in response to phases of increasing challenge, and sympathetic and parasympathetic systems did not appear coordinated in these boys with FXS. Clinical factors may be related to neural regulation of heart activity while molecular factors do not appear to be.     

重组神经生长因子受体基因在受体缺乏的神经母细胞瘤细胞系中的表达

神经母细胞瘤是儿童期的常见恶性肿瘤之一。临床上,半数以上神经母细胞瘤有明显的N-myc癌基因扩增。神经生长因子(NGF)可使某些神经母细胞瘤细胞分化成神经元样的细胞。但对有N-myc扩增的神经母细胞瘤则可能因NGF受体缺乏而无明显促分化反应。本研究运用重组DNA技术将人NGF受体基因重组到有N-myc扩增,且NGF受体表达很低的神经母细胞瘤系(IMR-32)中,经克隆化培养、筛选,建立了稳定的细胞系—IMR-32/NGFR和对照细胞系IMR-32/NEO。经用抗NGFR的单克隆抗体检测用Flow cytometry技术证实IMR-32/NGFR系中有明显的NGF受体表达,而其母系IMR-32和空病毒对照系IMR-32/NEO则无表达迹象,说明NGF受体表达在IMR-32/NGFR系中是特异的,并能同抗NGFR单克隆抗体特异结合。用Northern B10ting技术亦测得IMR-32/NGFR中NGFR的mRN A明显表达。而其母系IMR-32和对照系IMR-32/NEO则无明显表达。这说明IMR-32/NGFR系中NGFR在mRNA水平上亦是特异的。N-myc和K-ras癌基因在IMR-32、IMR-32/NEO、IMR-32/NGFR三系中无明显变化。在NGF处理后,形态上三系均无明显的分化迹象。但IMR-32/NGFR在神经原纤维轻链的表达上轻度增高。c-fos癌基因的表达见于所有三个细胞系,IMR-32/NGFR略强些。这些说明,在恢复了NGFR基因和表达之后,对N-myc和K-ra     

一氧化氮诱导HL-60细胞凋亡及其机制探讨

目的：观察一氧化氮对人类白血病细胞是否具有致凋亡作用，并研究Bcl-2基因和P53基因在此过程中的作用。方法：将不同浓度的外源性一氧化氮供体亚硝基铁氰化钠与HL-60细胞作用，观察其作用的时间效应和剂量效应；用MTT法观察NO对细胞的抑制作用，用透射电镜观察细胞结构改变，用DNA凝胶电泳、细胞DNA含量、DNA末端标记、Annexin-V/PI法等分析细胞凋亡，并用流式细胞法进一步观察在NO作用过程中凋亡调控因子Bcl-2和P53蛋白及线粒体膜蛋白表达变化。结果：NO能抑制HL-60细胞生长，并在一定的剂量范围内显示作用时间和剂量的量效关系；典型的细胞形态改变、DNA片段化、亚G1峰检出、DNA末端标记、Annexin-V/PT^-表达增加等证实。NO能诱导白血病细胞凋亡；在此过程中，P53蛋白表达上调，而Bcl-2蛋白表达下调，线粒体膜蛋白表达增加。结论：NO对HL-60细胞有强的致凋亡作用，Bcl-2和P53参与NO诱导HL-60细胞凋亡的调控。     

Renpenning syndrome in an Indian patient

Renpenning syndrome is one of the well‐characterized causes of X‐linked intellectual disability and is associated with microcephaly and various visceral malformations. Face is considered characteristic but the dysmorphism is subtle. Here we report an Indian adult with a very lean habitus, progressive atrophy of the upper back muscles, microcephaly, loss of cervical lordosis, and upper thoracic scoliosis. Using whole‐exome sequencing, a hemizygous deletion was identified in PQBP1 that leads to a frameshift and premature termination of translation. The loss of normal curvatures of cervical and upper thoracic spine due to muscular atrophy is a characteristic feature, though it may be age dependent.     

Central precocious puberty and abnormal chromosomal patterns

Central precocious puberty (PP) can be caused by chromosomal aberrations. We report three patients presenting with central PP in whom karyotype analysis demonstrated abnormal chromosomal patterns. The first patient was affected by the triple-X syndrome, commonly characterized by premature ovarian failure. The second patient, a girl with inv dup(15)(pter→q12::q12→pter), had a chromosomal aberration involving an imprinted region of the human genome, whose deletion is commonly associated with Prader-Willi syndrome (PWS) and hypogonadotrophic hypogonadism. The third patient was a boy carrying a rare chromosome abnormality, the duplication of chromosome 9 (q22→qter). All patients had mental retardation, which was mild in patient 1, moderate in patient 2, and severe in case 3. They underwent treatment with luteinizing hormone releasing hormone (LHRH) analogs, which were able to stop the progression of the sexual development. We confirm that chromosomal aberrations are an important cause of central PP, and that karyotype analysis in patients with PP and mental retardation, even if mild, is necessary because chromosomal abnormalities can be present.     

In vivo and in vitro correlates of food allergy.

Sera of 86 patients clinically sensitive to foods were tested by passive sensitization of human and/or monkey lung (127 tests) and the radioallergosorbent test (RAST) (72 tests), using whole-food antigens; the results were compared with skin (prick) testing. Results of the prick test correlated with history in 76% of cases; lung sensitization correlated with history in 37% and with prick test in 57%; and RAST correlated with history in 54% and prick test in 72%. It is concluded that a very large percentage of adverse reactions to foods are IgE-mediated. The prick test is of use in diagnosis, particularly when combined with RAST; the lung sensitization test is technically impractical and not a reliable indicator. The best diagnostic method is careful history with food challenge and withdrawal and rechallenge; the latter is safe except in patients with a history of violent reaction.     

Neurobehavioral phenotype in carriers of the fragile X premutation

There have been contradictory findings in the fragile X (fraX) literature about possible neurocognitive and psychological symptoms due to the fraX premutation (pM). The purpose of the present study was to investigate the relationship between CGG repeat length and neurobehavioral functioning in carriers of the fraX pM. Eighty‐five female carriers of the pM with allele sizes ranging from 59–166 were administered a comprehensive IQ test (WAIS‐III) and completed a questionnaire designed to measure psychopathology (Symptom Checklist (SCL)‐90‐R). No relationship between allele size and cognition was identified. A significant negative relationship between allele size and age was found, as well as a positive relationship between allele size and depression. Follow‐up analyses separating small and large allele sizes (below and above 100 CGG repeats) indicated that individuals with larger allele sizes scored significantly higher on the Interpersonal Sensitivity and Depression subscales of the SCL‐90‐R. Despite the limitation of few individuals with high CGG repeat lengths, our findings suggest that females with larger premutated alleles (≥ 100 repeats) display some clinical manifestations of fraX syndrome. © 2001 Wiley‐Liss, Inc.     

人工假肢膝关节微电脑控制装置的研究

高位截肢的伤残病人，即使安装了人工假肢，也因为人工假肢的关节不能自由活动，因而行走起来很吃力，动作不协调，姿态不美观。如果在人工假肢的关节处安装一个步进电机，采用微电脑控制技术，使步进电机按照人的意志转动，那么人在行走（或奔跑、弹跳、上下楼梯、下蹬起立等）时，假肢的逼真程度将会大大提高，动作也就十分自然。本文就这种构想谈了制作过程。     

CT三维重建在侧颅底的应用研究

目的 探讨CT三维重建在侧颅底的应用价值。方法 15例健康成人在Picker5000全身CT机上行连续轴位扫描，将扫描获得的原始数据输入Voxel Q图像后处理工作站，采用表面阴影法(surface shaded display，SSD)进行三维重建。结果 侧颅底CT三维重建能清楚显示正常侧颅底孔、裂和重要的骨性标志。重建的结构可整体显示或切割后单独显示，两均可在三维空间绕任意轴旋转任意角度。结论 三维CT能立体而直观的显示侧颅底骨性结构，有利于侧颅底外科手术方案的设计。