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     

太空发育鸡胚的前庭感受器细胞形态学研究

为了探讨太空微重力对鸡胚前庭感觉上皮细胞的形态发育的影响 ,选取在航天飞机 (STS-2 9)发育鸡胚和地面发育鸡胚各两只 ,利用计算机显微测量技术分别测量椭圆囊和球囊的毛细胞、支持细胞核的切面面积、周长、形状系数。太空发育鸡胚的球囊支持细胞核的切面面积、周长显著大于地面组 ,形状系数无差异 ;太空发育鸡胚的椭圆囊支持细胞核的切面面积、周长、形状系数以及椭圆囊和球囊毛细胞的切面面积、周长与地面发育鸡胚相比无明显差异。微重力可能对球囊支持细胞核的体积发育有影响 ,对椭圆囊和球囊的毛细胞以及椭圆囊支持细胞核的形态发育无影响。     

9株YONBAN相关TTV变异株全基因序列测定及其结构、分型的研究

目的：对9个TTV新分离株全基因序列测定，基因结构及基因分型的研究。方法：从9名TTV第4基因群感染阳性的婴儿血清中抽提取其DNA，用long inverted PCR扩增出全基因组，克隆和测定全基因组序列，并对测序结果进行计算机分析。结果：首次次测定了TTV第4基因群共9个新分离株的全基因序列，其中8个分离株代表核基因群首次报道的8个新基因型。结论：TTV基因组核酸序列具有高度异质性及基因型的高度多样性，但是，其独特的转录特性和基因组的基本结构在各自的基因群及基因型中十分保守。     

Race and the response to adrenergic blockade with carvedilol in patients with chronic heart failure

BACKGROUND: The benefits of angiotensin-converting-enzyme inhibitors and beta-blockers may be smaller in black patients than in patients of other races, but it is unknown whether race influences the response to carvedilol in patients with chronic heart failure. METHODS: In the U.S. Carvedilol Heart Failure Trials Program, 217 black and 877 nonblack patients (in New York Heart Association class II, III, or IV and with a left ventricular ejection fraction of no more than 0.35) were randomly assigned to receive placebo or carvedilol (at doses of 6.25 to 50 mg twice daily) for up to 15 months. The effects of carvedilol on ejection fraction, clinical status, and major clinical events were retrospectively compared between black and nonblack patients. RESULTS: As compared with placebo, carvedilol lowered the risk of death from any cause or hospitalization for any reason by 48 percent in black patients and by 30 percent in nonblack patients. Carvedilol reduced the risk of worsening heart failure (heart failure leading to death, hospitalization, or a sustained increase in medication) by 54 percent in black patients and by 51 percent in nonblack patients. The ratios of the relative risks associated with carvedilol for these two outcome variables in black as compared with nonblack patients were 0.74 (95 percent confidence interval, 0.42 to 1.34) and 0.94 (95 percent confidence interval, 0.43 to 2.05), respectively. Carvedilol also improved functional class, ejection fraction, and the patients' and physicians' global assessments in both the black patients and the nonblack patients. For all these measures of outcome and clinical status, carvedilol was superior to placebo within each racial cohort (P<0.05 in all analyses), and there was no significant interaction between race and treatment (P> 0.05 in all analyses). CONCLUSIONS: The benefit of carvedilol was apparent and of similar magnitude in both black and nonblack patients with heart failure.     

Comparison of the unlabeled and labeled pre-mRNA splicing assays in vitro

Pre-mRNA splicing is a fundamental process required for the expression of most metazoan genes. It is carried out by the spliceosome that catalyzes the removal of non-coding intron sequences to ligate exons into mature mRNA prior to transport and translation. The purpose of our study is to explore whether the in vitro unlabeled pre-mRNA splicing assay could be performed as an alternative method of splicing reaction other than the radiolabeled one. Two different splicing methods in vitro , P labeled and unlabeled pre-mRNA as the substrates in the reaction, were investigated. The radiolabeled products were visualized by autoradiography while the unlabeled products were observed by Ethidium Bromide (EB) staining. As a result, although there are more unspecific bands in the EB staining assay than 32P labeled one, the RNA products of in vitro splicing could be observed clearly. This suggests that the unlabeled pre-mRNA splicing assay can be an optional substitution for the isotope-labeled assay.     

Urinary leukotriene E(4), eosinophil protein X, and nasal eosinophil cationic protein are not associated with respiratory symptoms in 1-year-old children

BACKGROUND: Eosinophilic airways inflammation forms the pathophysiologic basis for a proportion of children at risk of developing recurrent wheezing. Early preventive measures and/or anti-inflammatory treatment may be guided by the identification of such children. We aimed to study the relationship between respiratory symptoms and indirect markers of airway inflammation. METHODS: We measured eosinophil protein X (EPX) and leukotriene E(4) (LTE(4)) in urine, as well as eosinophil cationic protein (ECP) in nasal lavages, in a random sample of 1-year-old children with a family history of atopy who participated in an international multicenter study on the prevention of allergy in Europe. For urine analyses, 10 children with upper respiratory illness and 19 healthy children without a family history of atopy were also enrolled. Endogenous urinary LTE(4) was separated by HPLC and determined by enzyme immunoassay with a specific antibody. The concentrations of nasal ECP and urinary EPX were determined by RIA analysis. RESULTS: One hundred and ten children (mean age: 1.05+/-0.1 years) were enrolled. Prolonged coughing during the first year of life was reported in 29 children, wheezy breathing in 17 children, and dry skin in 33 children. A doctor's diagnosis of wheezy bronchitis was given to 17 children. Sensitization to dust mites (specific IgE > or =1.43 ML/units) was detected in two children. Children with a doctor's diagnosis of atopic dermatitis within the first 12 months of life (n=6) had significantly higher urinary EPX than children without this (66.7 vs 30.1 microg/mmol creatinine, P=0.01). Urinary excretion of EPX and LTE4 showed a weak correlation (r=0.22, P=0.02). There were no significant differences in urinary excretion of EPX and LTE(4) or nasal ECP between children with and without respiratory symptoms (P>0.1). CONCLUSIONS: At the age of 1 year, urinary EPX is increased in children with atopic dermatitis. With regard to respiratory symptoms, urinary and nasal inflammatory parameters are not helpful in characterizing the phenotype of a single patient.     

Evolution of age at menarche and at onset of regular cycling in a large cohort of French women

BACKGROUND: Early exposure to ovarian hormones is considered to increase breast cancer incidence. The age at which the ovaries become functional is thus important. METHODS: We explored the evolution of age at first menstruation and at onset of regular cycling in 86 031 women participating in the E3N-EPIC cohort study, part of the European Prospective Investigation into Cancer. RESULTS: We observed an increase in mean age at menarche among women born between 1925 and 1930, followed by a steady decrease in the youngest birth cohorts. In contrast, age at onset of regular cycling increased gradually from 1925 onwards. There was thus a steady increase in the interval between age at menarche and at onset of regular cycling, mainly due to an increase in the percentage of women in whom regular cycling started at least 5 years after menarche (from 9.0% among women born in 1925-1929 to 20.8% in those born in 1945-1950). The increase in the interval between menarche and onset of regular cycling was even greater among women with a late menarche. CONCLUSIONS: This increase might be due to a change in dietary intake and/or physical exercise aimed at achieving the slim silhouette desired by the younger generations.     

大鼠新生期皮下注射谷氨酸单钠对成年后下丘脑ACTH神经元和正中隆起CRF神经纤维免疫反应性的影响

本文采用过氧化酶—抗过氧化酶(PAP)的免疫组织化学和荧光免疫组织化学的方法,研究了新生期大鼠皮下注射谷氨酸单纳(MSG)对成年后下丘脑弓状核促肾上腺皮质激素(ACTH)神经元和正中隆起内促肾上腺皮质激素释放因子(CRF)神经纤维免疫反应的影响。新生期MSG处理后,弓状核中ACTH神经元的数目明显减少,正中隆起CRF样免疫反应末稍也大大减少,减少程度随MSG剂量增大而增加。提示MSG通过损伤前阿黑皮素(POMC)衍生的神经多肽,从而影响下丘脑—垂体—肾上腺皮质轴的功能。     

大鼠单克隆抗体——Ⅶ.用降植烷和福氏佐剂预处理大鼠后腹水产生及单克隆抗体产量的增加

作者研究了腹腔注射降植烷、福氏不完全佐剂(IFA)以及上述两种佐剂的混合物(V/V)(称PIFA)对Louvain大鼠腹水产生及单克隆抗体(McAb)产量的影响。当腹腔注射杂交瘤或免疫细胞瘤细胞的同时注射2ml PIFA可获得最佳结果。若与未经处理的对照大鼠相比,腹水产生增加4.7倍,单克隆抗体产量增加6倍多。 大鼠-大鼠杂交瘤系统有以下优点:①在小鼠系统不适宜的情况下,可用大鼠代     

不同型Kaposi肉瘤的免疫表型观察

对Kaposi肉瘤(KS)的免疫表型特征，仍有不同观点，多数学者认为是一恶性肿瘤，也有学者认为是一增生性病变。我们对30例地方性和AIDS相关KS做了观察。