大鼠眼外肌成肌细胞的增殖及分化特征

目的:完善眼外肌成肌细胞体外培养、鉴定的方法及观察其生物学特性。方法:实验于2005-02/08在青岛大学医学院附院中心实验室(省级实验室)完成。取出生后3～7d的大鼠,通过大鼠眼外肌细胞的取材、分离、消化、培养等技术,观察细胞的形态、生长曲线、细胞融合率,观察大鼠眼外肌卫星细胞的增殖与分化能力,利用成肌细胞标记物α-横纹肌肌动蛋白、中间丝结蛋白免疫细胞化学染色对所获得的细胞进行鉴定。结果:①成肌细胞的生长情况:在生长培养基作用下,细胞增殖旺盛;在分化培养基条件下,细胞分化良好,可融合成肌管。②成肌细胞融合率:在24h和48h融合率提高明显,72h达高峰,之后不再变化。③细胞免疫化学检测结果:α-横纹肌肌动蛋白和中间丝结蛋白免疫细胞化学染色阳性。结论:体外培养的大鼠眼外肌卫星细胞具有良好的增殖与分化能力,其生物学特征同骨骼肌卫星细胞。     

The regulation of hemopoiesis in long-term bone marrow cultures. II. Stimulation and inhibition of stem cell proliferation

The isolation of a DNA synthesis inhibitor (NBME fraction IV) and stimulator (RBME fraction III) specific for the hemopoietic stem cell (CFU-s) from freshly isolated normal adult and regenerating murine bone marrow, respectively, has been well documented. We have utilized long- term liquid bone marrow cultures in a further analysis of the role of these factors in the regulation of CFU-s proliferation. Our results show that shortly after feeding, at a time when the cultured CFU-s are actively proliferating, high levels of the hemopoietic stem cell proliferation stimulator fraction III can be isolated from the culture medium. In contrast, the presence of essentially noncycling CFU-s found in cultures fed 8-10 days previously correlates with high levels of the hemopoietic stem cell inhibitor fraction IV. These results suggest that a certain balance between these factors determines CFU-s proliferation in the long-term cultures. In support of this, DNA synthesis in actively cycling CFU-s in the long-term cultures is inhibited for at least 3 days by the addition of excess NBME fraction IV (inhibitor). Furthermore, DNA synthesis in noncycling cultured CFU-s is stimulated for at least 5 days by the addition of RBME fraction III (stimulator).     

Home blood pressure monitoring in children: how many measurements are needed?

OBJECTIVE: To investigate the minimum schedule of blood pressure (BP) measurements necessary to provide a reliable assessment of home BP (HBP) in children and adolescents. METHODS: Subjects aged 6-18 years referred for elevated BP were assessed with HBP monitoring (6 workdays, duplicate morning and evening measurements) and 24-h ambulatory BP monitoring (ABP). Criteria for HBP reliability were its reproducibility (test-retest correlations and SD of differences (SDDs) between repeated measurements), its stability (average home BP of an increasing number of readings and its SD), and its relationship with ABP. RESULTS: Data from 100 subjects were analyzed (mean age 13 +/- 2.8 (SD) years, 61 boys). The reproducibility of 3-day HBP (r 0.88/0.79, SDDs 5.1/4.9, systolic/diastolic) was superior to that of a single (r 0.79/0.65, SDDs 7.6/7.1) or 2-day HBP (r 0.85/0.72, SDDs 6.1/5.4). By averaging up to 12 readings (3 days), there was a progressive decline in average HBP, with no further decline thereafter. The SD of average HBP was also progressively reduced, with little change after day 3. The association of HBP with ABP was improved by averaging more readings up to 12, with no further improvement when more readings were averaged. The exclusion of first-day measurements slightly increased the SD of average HBP and weakened the correlation with ABP, probably due to reduced number of readings. CONCLUSIONS: In children and adolescents, 3-day monitoring with duplicate morning and evening measurements appears to be the minimum schedule for the reliable assessment of HBP.     

Autoantibodies against bactericidal/permeability-increasing protein in patients with cystic fibrosis

Cystic fibrosis (CF), a genetic disorder, is characterized by chronic pulmonary infection/inflammation which leads to respiratory failure. The presence of anti-neutrophil cytoplasmic autoantibodies (ANCA) has previously been observed in the sera of patients with CF. In view of the known relationship of ANCA with primary vasculitis and of their putative pathogenetic role in these disorders, we studied the presence, specificity and isotype of ANCA and their clinical associations in 66 adult CF patients. None of the 66 CF samples had autoantibodies to the major ANCA antigens, proteinase 3 or myeloperoxidase. However, 60/66 (91%) CF samples contained IgG and 55/66 (83%) IgA, autoantibodies to bactericidal/permeability increasing protein (BPI), a recently characterized ANCA specificity. All the IgA anti-BPI-positive samples were also IgG anti-BPI-positive. The autoantibody specificity was confirmed by inhibition assay and immunoblotting of CF sera against a neutrophil granule preparation. Furthermore, in this cross-sectional study, anti-BPI levels were inversely correlated with the observed reductions in FEV1 and FVC (IgA anti-BPI and FEV1: r = 0.508, <it>p</it> &lt; 0.0001), and both IgG and IgA anti-BPI levels were higher in CF patients with secondary vasculitis (<it>n</it> = 6) than in those without (<it>p</it> &lt; 0.05). ANCA with specificity for BPI were present in the majority of CF sera in this study and autoimmune processes may be associated with the development of pulmonary injury in CF.