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Biomedical subjects

Qun Chen

Publications and source records attributed to Qun Chen.

79 records · Page 5Linked to original sources

[Correlation of the factors on benign prostatic hyperplasia combined with obstruction].

Benign prostate obstruction(BPO) means bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH), which concerns BPH, and lower urinary tract symptoms(LUTS). To treat the BPO is the main purpose of therapy on BPH in clinic. This review includes recent advances in study of changes on urodynamics(UDS), morphology, prostatic composition, which occur in BPO.

Humans↗

[Preparation of calcium phosphate coatings on surfaces of commercially pure titanium induced by simulated body fluid].

All samples were divided into three groups and subjected to three different surface treatments, i.e. untreated group, group etched with mixed acid of 1:1 HCl and H2SO4 followed by immersion in 6N NaOH solution at 60 degrees C for 24 h and group etched with mixed acid of 1:1 HCl and H2SO4 followed by immersion in 6N NaOH solution at 60 degrees C for 24 h then heated at 600 degrees C for 1 h. After soaked in simulated body fluid for two weeks, a thin calcium phosphate coatings was precipitated on the surfaces of the two treated samples. Results of SEM and EDX showed that calcium phosphate coatings on the surfaces of the titanium samples etched and heated were more even than the titanium samples etched without heating. The analysis of XRD demonstrated the main component of calcium phosphate coating was hydroxyapatite.

Body Fluids↗

Effect of artificial acid rain and SO2 on characteristics of delayed light emission.

The structure and function of chloroplast in plant leaves can be affected by acid rain and air pollution. The photosystem II in a plant is considered the primary site where light-induced delayed light emission (DLE) is produced. With the lamina of zijinghua (Bauhinia variegata L.) and soybean (Glycine max (L.) Merr.) as testing models, we studied the effects of artificial acid rain and SO2 on characteristics of DLE by using a home-made weak luminescence detection system. The results show that the changes in DLE intensity of green plants can reflect the changes in chloroplast intactness and function. With proper calibration, DLE may provide an alternative means of evaluating environmental acid stress on plants. The changes in DLE intensity may provide a new approach for the detection of environmental pollution and its impact on the ecosystem.

Acid Rain↗

Tumor suppressor gene 14-3-3sigma is down-regulated whereas the proto-oncogene translation elongation factor 1delta is up-regulated in non-small cell lung cancers as identified by proteomic profiling.

Lung cancer, a leading cause of cancer deaths, consists of two major groups: small cell lung cancer (SCLC) and nonsmall cell lung cancer (NSCLC) with the NSCLC accounting for approximately 75% cases of lung cancers. It has been suggested that molecular changes including overexpression of oncogenes and decreased expression of tumor suppressor genes are responsible for lung carcinogenesis. In this study, we analyzed protein profiles of four different human NSCLC cell lines compared with normal human bronchial epithelial cells using two-dimensional PAGE and MALDI-TOF mass spectrometry. We identified 12 protein spots with different expressions between the normal and cancer cells. Of these proteins, vimentin, cytokeratin 8, YB-1, PCNA, Nm23, hnRNP A2/B1, and HSP90beta were known to be up-regulated in lung cancers, which is consistent with the current study. We also found that the expression of M-type pyruvate kinase is altered in NSCLC likely due to changes in translational control and/or differential phosphorylation of the protein. Interestingly, the expression of the tumor suppressor gene 14-3-3sigma is down-regulated while that of the proto-oncogene TEF1delta is up-regulated in NSCLC cells. On the basis of these observations and previous studies, we propose that the altered expression of 14-3-3sigma and TEF1delta may be involved in lung carcinogenesis.

14-3-3 Proteins↗

Feasibility of using fluoresceinyl Cypridina luciferin analog in a novel chemiluminescence method for real-time photodynamic therapy dosimetry.

Singlet oxygen ((1)O(2)) is the most important cytotoxic agent in photodynamic therapy (PDT). The feasibility of using a chemiluminescence (CL) probe, 3,7-dihydro-6-[4-(2-(N'-(5-fluoresceinyl)thioureido)ethoxy)phenyl]-2-methylimidazo{1,2-a}pyrazin-3-one sodium salt (fluoresceinyl Cypridina luciferin analog, FCLA), to monitor (1)O(2) production during PDT is evaluated in vitro. Lymphoma cells were treated with various protocols of PDT. The results show that the FCLA-CL production during PDT is linearly related to the corresponding cytotoxicity, regardless of the treatment protocol. With minimum cytotoxicity and interference to the PDT treatment outcome, the FCLA-CL system is an effective means to quantify PDT (1)O(2) production and may provide an alternative real-time dosimeter.

Cell Survival↗

Enhancement of fluoresceinyl cypridina luciferin analog chemiluminescence by human serum albumin for singlet oxygen detection.

Fluoresceinyl cypridina luciferin analog (FCLA) is a chemiluminescence (CL) probe for detecting reactive oxygen species (ROS). Its efficiency for detecting singlet oxygen (1O2) can be significantly enhanced in the presence of human serum albumin (HSA). This phenomenon may apply to important applications for both research and clinical testing, because of the broad presence of HSA in the human system. In the current study the mechanism of the FCLA-HSA CL system is studied by means of direct CL measurement and spectroscopy techniques. Our results show that FCLA can combine with HSA via a single binding site to form a complex. The CL efficiency of the system is largely governed by an intersystem energy transfer between the two components upon interaction with 1O2. The CL production reaches maximum in a synergetic manner when equal amounts of FCLA and HSA are present simultaneously, but production is less at other ratios. The results also show that the combination of FCLA with HSA does not significantly alter the ROS selectivity of FCLA. In conclusion, our study shows that FCLA and HSA can combine and form a complex with higher CL efficiency. This provides us a new approach in designing CL techniques for studying ROS.

Energy Transfer↗