ABSTRACT
There is high demand for a sensitive method for miRNA detection in clinical diagnosis. In this work, we developed a method for miRNA detection based on the surface plasmon-enhanced energy transfer ( SPEET ) between gold nanoparticles ( AuNPs ) and silver nanoclusters ( AgNCs ) , coupled with DNA polymerase and nicking enzyme-assisted isothermal amplification for target recycling. Two DNA probes ( Probe a and Probe b) were assembled onto the surface of AuNPs to form Probe b-Probe a-AuNP conjugates. Probe a consisted three domains:the complementary sequence of miRNA, the specific site of the nicking enzyme, and the self-assembly sequence for AgNCs. The 3′ end of Probe a was modified with thiol as a binding site for AuNPs. The SPEET of AgNCs and AuNPs was inhibited when miRNA was added to produce the dumbbell shaped template by polymerase. The template could promote synthesis of AgNCs, resulting in replacement and subsequently recycling of the target molecule for signal amplification. In comparison with the traditional method of miRNA detection with commercial RT-PCR kits, this method avoided the process of reverse transcription and was easy to perform. In addition, this method with a detection limit of 2. 5×10-11 mol/L was cost-effective, label-free, and highly selective for detecting miRNA, and could be applied to the analysis of miRNA in biological samples.
ABSTRACT
Objective To discuss the method,safety and effect of malignant pancreas tumor treated by CT guided percutaneous embedding of~(125)I. Methods 32 cases of malignant pancreas tumor with CT scan and contrast enhancement were retrospectively analysed.All the cases had been confirmed pathologically be- fore CT guided therapy.The number of~(125)I particle was 12～46,The distance between particles was 0.～1.2 cm. The number of puncture point was 1～2.The number of puncture direction was 2-5 times.Results Regarding 32 cases for 1 month,the size of the tumor reduced in 11 cases,no change in 20 cases,and increased in 1 case.As for 31 cases for 2 months,the size reduced in 16 cases,no change in 13 cases,and enlarged in 3 cases.Regarding 30 cases for 3 months,the size reduced in 18 cases,no change in 11 cases,and increased in 3 cases. Regarding 28 cases for 6 months, he size reduced in 10 cases, no change in 5 cases, and in- creased in 13 cases.Regarding 22 cases for 1 year,12 cases had been done the second therapy,the size of the tumor reduced in 16 cases,no change in 3 cases,and increased in 3 cases.Conclusion The size of pancreas tumors were reduced obviously,the symptoms were relieved after the treatment.The method turned out to be safe and accurate.
ABSTRACT
<p><b>BACKGROUND</b>To observe cytopathogenic effect of Hantaan virus (HV) on cultured human bone marrow cells.</p><p><b>METHODS</b>Light and transmission electron microscopy and direct immunofluorescent technique were applied to study cellular structure especially ultrastructural changes of bone marrow cells from patients with Hantaan virus infection. Bone marrow cells of one healthy volunteer were also studied as control.</p><p><b>RESULTS</b>The antigen of HV was found in bone marrow cells of 20 of 27 HFRS patients by the aid of direct immunofluorescent technique. It was found that the granulocytes had the highest percentage of HV antigen positive cells (76%), followed by monocytes (65%), lymphocytes (40%), megakaryocytes (20%) and the lowest was found in erythrocytes (3.7%). The injury of cell membrane after infection with HV was significantly more severe than that in the control group under the light and electron microscopy.</p><p><b>CONCLUSION</b>This study demonstrated that HV could attack human bone marrow cells and cause cytopathogenic effect on them.</p>