基于碳纳米管修饰的无酶型新型甲胎蛋白安培免疫传感器研究

目的构建新型甲胎蛋白安培免疫传感器。方法首先在玻碳电极（GCE）表面修饰一层羧基化碳纳米管（CNTs）,然后利用带负电荷的DNA分子和带正电荷的硫堇之间的静电作用,层层自组装修饰硫堇以增强检测信号,然后利用硫堇的氨基固定纳米金,以便固定抗体,最后利用牛血清白蛋白封闭未结合位点。结果修饰的碳纳米管能够显著地提高电极的导电性,利用层层组装技术修饰了5层硫堇。在优化的条件下（pH7.0,温浴时间25min）,制作的甲胎蛋白免疫传感器线性范围在0.5～25ng/ml内,检测限0.02ng/ml。结论成功利用层层自组装技术构建新型基于碳纳米管修饰的无酶型甲胎蛋白安培免疫传感器,该传感器灵敏度高,特异性好,有望成为原发性肝癌早期诊断的新方法。     

Inactivation of pathogens in platelet concentrates by using a two-step procedure

BACKGROUND AND OBJECTIVES: Platelet concentrates are contaminated with residual leucocytes and may also be infected with viruses and bacteria. We investigated whether these pathogens can be inactivated by a two-step procedure comprising photodynamic treatment in the presence of the phenothiazine dye, thionine, followed by irradiation with ultraviolet light (UV-B, wavelength range 290-330 nm). MATERIALS AND METHODS: Platelet concentrates were prepared from buffy coats. The concentrates were spiked with different viruses, bacteria and leucocytes, then illuminated with yellow light in the presence of thionine at dye concentrations between 1 and 5 microm and with UV-B at doses up to 2.4 J/cm2. The infectivity of samples and the viability of leucocytes were assayed before and after treatment. The influence of treatment on in vitro platelet function was also examined. RESULTS: The inactivation of free viruses in platelet concentrates by photodynamic treatment with thionine/light was significantly enhanced when it was followed by irradiation with UV-B. The inactivation of leucocytes and of bacteria by UV-B was improved when it was preceded by thionine/light. Sterile platelet concentrates were prepared from buffy coats infected with Staphylococcus epidermidis. Platelet function and the storage stability of platelet concentrates were only moderately influenced by the two decontamination steps. CONCLUSIONS: Photodynamic treatment in the presence of the phenothiazine dye, thionine, followed by low-dose UVB, has the potential to inactivate viruses, leucocytes and bacteria, which might contaminate platelet concentrates. Both treatments complement each other.     

Significance of adrenoceptor-mediated atrial natriuretic factor release in normal humans: Erratum

Abstract

The orosomucoid content of serum has been determined in healthy infants and children. Analyses of haptoglobin and of electrophoretic protein fractions have also been made.

The mean umbilical cord serum level of orosomucoid was significantly lower than the level in the maternal serum. Apart from a transient increase during the first week of life, low serum levels were found up to the age of three months.

The alpha₁, alpha₂ and beta globulins showed essentially the same changes with age as the orosomucoid.

The serum content of haptoglobin was very low at birth and rose slowly to the level found in adults.     

Small pancreatic tubular adenocarcinomas: Clinicopathological analysis with immunohistochemical and histochemical evaluation

Ten cases of surgically resected small pancreatic tubular adenocarclnomas (PTA), grossly 2 cm or less were analyzed. Nine patients presented with symptoms. The cumulative 5 year survival rate was 14.8%. According to the criteria proposed by the Japanese Pancreatic Society, in three patients the PTA was stage I and in seven patients it was stage II. lmmunohistochemical study detected overexpression of p53 In six PTA, of c-erbB-2 in four PTA, and of Ha- ras p21 in six PTA. the p53 overexpression was closely related to the poor clinical course ( P< 0.05). All PTA focally had gastric mucin. In eight cases, mucous metaplasia was frequently found in the non-cancerous pancreatic tissues. Most of the mucous metaplastic cells had gastric mucin, and their staining patterns resembled those of the respective PTA. These findings support the putative hypothesis that most PTA arise from 'gastric mucous cell metaplasia'. However, in two cases, mucous metaplasia was not found. In one other case, minute dysplastic glands determining the existence of in situ carcinoma or intrapancreatfc metastasis were found in the islet of Langerhans, relatively distant from the main cancer. These findings also present the possibility that some PTA develop de nowo without mucous metaplasia.