Design of shipborne magnetic resonance imaging system / 医疗卫生装备

Objective To develop a magnetic resonance imaging (MRI) system for pelagic definitive treatment platforms, large support ships and ocean vessels.Methods The system was designed based on normal electromagnetic MRI technology, which was composed of six parts of gradient system, magnet system, coil system, radiofrequency system, spectrum control system and imaging system.The magnet system was developed with C-shaped open magnet,five systems were designed such as a super-stability excitation system, a super-sensitivity signal detection system, a magnetic filed dissipation precision control system, a shipborne sensitive equipment vibration control system and a software system, and a set of technical detection standards was proposed.Results The developed MRI system realized mobile imaging,gained advantages in imaging velocity,resolution,magnetic field dissipation control,ship bump resistance and environmental suitability,and thus could be used in marine mobile conditions. Conclusion The developed MRI system meets the requirements of pelagic medical treatment, and contributes to improving pelagic medical support ability of Chinese navy.

Effects of Niaoduqing Granule on quality of life and TGF- β1/Smad signalling in chronic renal failure rats received peritoneal dialysis / 实用医学杂志

Objective To investigate the effect of Niaoduqing Granule on the quality of life and the activa-tion of TGF-β1/Smad signalling in chronic renal failure rats received peritoneal dialysis. Methods Thirty SD rats were used to establish peritoneal dialysis models and were randomly divided into the model group(group M),the low dose group(group L),and the high dose group(group H).The dosage of group L and group H was 2 and 4 g/(kg·d),respectively. The body mass,the number of independent activities,the index of renal hypertrophy, Scr,BUN,experssion of TGF-β1 and p-Samd2/3 were determined. Results The body weight growth rate was shown decreased as follows:group N>group H>group L>group M.The number of spontaneous activity of group M decreased significantly than those in other groups. Scr,BUN and kidney hypertrophy index were significantly different among the four groups.Compared with group M,BUN,Scr,kidney hypertrophy index,levels of TGF-β 1 and p-Samd2/3 were significantly decreased in group L and H. Levels of TGF-β1 and p-Samd2/3 were signifi-cant different between group L and H. Conclusions Niaoduqing Granule can improve the quality of life and re-duce the level of serum creatinine and urea nitrogen in chronic renal failure rats received peritoneal dialysis,and the mechanism may be associated with the regulation of TGF-β1/Smad signaling pathway.

The research of the foamy fracture fixation splint / 中国医疗器械杂志

A new production method of fracture fixation splint is introduced in the paper. The basic raw materials are multi-isocyanic acid, mixed with surfactants, catalysts, fillers, and so on. The splint, with light weight, high strength, and good injured anastomosis site, could be able to shape easily. It is dry and comfortable, avoiding a gas-tight uncomfortable feeling, easy to remove, remodel, nurse, clean and disinfect after fixed. Patients also could film review directly with fixed splint.

Effects of specific small interfering RNA on Smoothened expression and LoVo cell proliferation and apoptosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of specific small interfering RNA (siRNA) on Smoothened (Smo) gene expression and the proliferation and apoptosis of colorectal cancer LoVo cells.</p><p><b>METHODS</b>Three different siRNAs (siRNA-1, siRNA-2, and siRNA-3, respectively) were transfected into LoVo cells via cationic liposome, and the changes of Smo mRNA level were determined using semi-quantitative RT-PCR 48 h after transfection. Flow cytometry and MTT assay were performed to assess the effect of the siRNAs on the proliferation and apoptosis of LoVo cells.</p><p><b>RESULTS</b>Forty-eight hours after Smo siRNA-1 transfection, Smo mRNA expression in LoVo cells decreased by about 63.56%, a reduction significantly greater than that in cells transfected with the other two siRNAs. The cell proliferation decreased significantly after Smo siRNA-1 transfection in comparison with the control cells, and 48 h after transfection, significantly higher apoptosis rate was observed in Smo siRNA-1-transfected cells than in the control cells.</p><p><b>CONCLUSION</b>Specific siRNA can significantly decrease Smo mRNA expression and inhibit the proliferation while inducing apoptosis of LoVo cells.</p>

Antitumor effect of GPI-CD80 fusion protein in nude mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the antitumor effect GPI-CD80 fusion protein and its mechanisms.</p><p><b>METHODS</b>A tumor vaccine was prepared by culturing HepG2 cells in the presence of purified GPI-CD80 followed by inactivation with mitomycin, with mitomycin-inactivated HepG2 cells as the control group. The two preparations were co-cultured with nude mouse splenic lymphocytes, and the changes of lymphocyte proliferation and the production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) were detected by MTT assay. The cytotoxic T-lymphocyte (CTL) activity was evaluated by LDH-release assay, and the changes of gross tumor volume were measured in tumor-bearing nude mice after administration of different vaccines.</p><p><b>RESULTS</b>The application of GPI-CD80 tumor vaccine resulted in significantly increased optical density, IL-2 and IFN-gamma levels and CTL activity of the nude mouse splenic lymphocytes in comparison with the control groups. The average tumor volume in nude mice treated with GPI-CD80 tumor vaccine was significantly smaller than that in negative control and blank control groups.</p><p><b>CONCLUSION</b>GPI-CD80 fusion protein may inhibit the tumor growth velocity in nude mice, possibly by promoting lymphocyte proliferation, stimulating the production of the cytokines IL-2 and IFN-gamma, and enhancing of CTL activity.</p>

The tracking of allogenic grafted rat bone marrow stem cells in rat liver and their role on repairing injured liver / 中华外科杂志

<p><b>OBJECTIVE</b>To study the location, immigration of allogenic grafted Feridex-labeled rat bone marrow stem cells (BMSCs) in chemically-induced acute injured livers and their role on repairing the injured liver function.</p><p><b>METHODS</b>The rat models of chemically-induced acute hepatic injury established with CCl4 Feridex-labeled BMSCs were injected into the injured livers. Magnetic resonance imaging (MRI) examination was conducted on rat livers, the levels of ALT, AST and Fe3+ in the serum and hepatic tissues were studied 6 h before and 6 h, 1 w and 5 w after injection.</p><p><b>RESULTS</b>Cellular necrosis, congestion in the hepatic sinusoid and infiltration of inflammatory cells were seen in the model livers. Above 90 percent of the cells were Feridex-labeled BMSCs positive by prussian blue staining and iron particles were found in their endochylema through electron microscopy. MRI examination at the sequence of SE-T2WI showed remarkably low signal changes 6 h after injecting Feridex-labeled BMSCs and the site with signal changes gradually expanded 1 and 5 w after injection. Comparatively, the changes of low signal images at each time point in the injured livers were more obvious than those of the controls at all time points, respectively. Simultaneously, pathological injuries in the livers were ameliorated and the levels of ALT and AST in serums declined: these changes in the Feridex-labeled BMSCs group were more obvious than those in the non-Feridex-labeled BMSCs group. Uniformly, there were no significant differences between the Feridex-labeled BMSCs group and the non-Feridex-labeled BMSCs group in view of histopathological examination and serological examination (including ALT, AST, Fe3+ levels) at all time points.</p><p><b>CONCLUSIONS</b>The liver function in the model of chemically-induced acutely-injured liver may be repaired by BMSCs implantation. Traced by MRI, BMSCs in the injured liver of rats disperse at a higher rate than in the normally fed ones.</p>

Investigation of the role of hepatic oval cell in primary hepatocarcinogenesis using specific Y chromosome / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the role of hepatic oval cell in primary hepatocarcinogenesis using specific Y chromosome.</p><p><b>METHODS</b>The model of hepatic oval cell proliferation was established by feeding 30 male Wistar rats with 0.06% 3'3-diaminobenzidine (DAB) for 4 weeks. Another 40 female Wistar rats were equally randomized into two groups: control group and experimental group. Experimental group was inoculated with oval cells suspension from the prepared male rats under the hepatic amicula and fed with DAB for 14 weeks continuously to promote hepatocarcinogenesis. Control group was fed with DAB for 14 weeks. After primer fragments were worked out on the male rats' SRY genes using the software of primer design, DNAs were extracted from the hepatic carcinomas of the female rats of the two groups and then amplified with PCR. Electrophoretic analysis was performed on the products.</p><p><b>RESULTS</b>After 14 weeks, primary hepatocarcinogenesis was found in the livers of all the 40 female rats. Electrophoresis showed the positive straps from the experimental group with the same length to the designed segments, whereas no positive straps were seen in the control group.</p><p><b>CONCLUSIONS</b>The hepatic oval cells can differentiate into hepatic cancer cells, which provides the evidence that the hepatocellular carcinoma has its source from the hepatic oval cells.</p>

Microenvironment of positive pressure powered air purifying medical protective equipment / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the filtration efficiency of a positive pressure powered air purifying medical protective equipment and the effect of the flow rate on the microenvironment of the equipment.</p><p><b>METHODS</b>The filtration efficiency of high efficiency particulate air (HEPA) filter was measured with the biologic aerosol of simulating virus (Escherichia coli bacteriophage f(2)). The simulation work was done at the walk rate of 4 km/h in summer. The effect of the flow rate on the oxygen content, the carbon dioxide content, the temperature and the humidity of the microenvironment of the equipment was investigated. The clinical experiments were conducted in three appointed hospital for fighting against SARS.</p><p><b>RESULTS</b>The HEPA filter could filtrate 99.99% simulating viruses in the air. When the flow rate ranged from 75 to 125 L/min, the microenvironment parameters of the equipment were: the oxygen content was between 19.6% and 20.1% (the physiological safety limit is more than 14.6%); the carbon dioxide content ranged from 0.43% to 0.57% (the physiological safety limit is less than 1.0%); the temperature was between 32.0 degrees C to 32.2 degrees C; the humidity ranged from 49.7% to 59.4% (the physiological safety limit is the temperature 31 degrees C and the humidity 85% or temperature 38 degrees C and humidity 50%). Each microenvironment parameter met the demand of a healthy person under the normal workload. In the clinical experiments, the doctors wearing the equipment who performed the tracheotomy for a SARS patient in a deep coma were not infected.</p><p><b>CONCLUSION</b>The medical protective equipment can protect the doctor and nurse in SARS contaminated areas effectively and improve their work conditions.</p>

Histological observations of chemically induced acute hepatic injury repaired by allogeneic bone marrow stem cell transplantation / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the possibility of repairing chemically induced acute hepatic injuries with allogeneic bone marrow stem cell (BMSC) transplantation.</p><p><b>METHODS</b>A SD rat model of CCl(4)-induced acute hepatic injury was established, which received transplantation of BMSCs (2.0 ml, 1x10(6)/ml) or normal saline injection into the local liver parenchyma, respectively. The rats were sacrificed at 6 h before and 6 h, 1, and 5 weeks after transplantation, and the livers were prepared for microscopic examination.</p><p><b>RESULTS</b>Cellular necrosis, bridging necrosis, congestion in the hepatic sinusoid, and inflammatory cell infiltration were seen in the chemically injured livers 6 h after model establishment, and these changes were ameliorated in rats receiving BMSC transplantation.</p><p><b>CONCLUSIONS</b>Allogeneic BMSC transplantation can repair chemically induced acute liver injuries.</p>

Expression of Smo protein and the downstream transcription factor Gli1 protein in Sonic hedgehog signal transduction pathway in gastric carcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the expression of Smo protein and the downstream transcription factor Gli1 protein in Sonic hedgehog signal transduction pathway in gastric carcinoma.</p><p><b>METHODS</b>A tissue microarray was constructed using 85 gastric carcinoma and 25 normal gastric mucosa specimens. The expression of Smo and Gli1 proteins were detected immunohistochemically and the correlation between their expression in gastric carcinoma was analyzed.</p><p><b>RESULTS</b>Only weak expression, if any, of Smo and Gli1 proteins was detected in normal gastric mucosa, but in papillary adenocarcinoma, tubular adenocarcinoma and poorly differentiated adenocarcinoma, their expressions were significant increased as the differentiation degree was lowered. Smo protein expression in gastric carcinoma was significantly correlated with that of Gli1 protein with correlation coefficient of 0.989 (P<0.001).</p><p><b>CONCLUSION</b>The abnormal activity of Sonic hedgehog signal transduction pathway may play an important role in the occurrence of papillary adenocarcinoma, tubular adenocarcinoma and poorly differentiated adenocarcinoma, and this abnormality is associated with Smo protein overexpression, which upregulates the expression of the downstream transcription factor Gli1 protein.</p>