BACKGROUND:The electrical impedance tomography (EIT) is a kind of examination that is used to non-invasively measure the change and distribution of electrical bio-impedance by reconstructing the frequency response obtained by electrical stimuli applied onto the human body. The characteristics of impedance of any tissues are of great importance to the imaging of EIT and locating and monitoring the lesion focus.OBJECTIVE: To measure the human brain impedance in the frequency range from 0.1 Hz to 1 MHz and to compare these with those of other human tissues and the rabbit brain tissues.DESIGN: An observational experiment.SETTING:The Department of Medical Electric Engineering of the Biomedical Engineering College of the Fourth Military Medical University of Chinese PLA.MATERIALS:The experiment was conducted at the Otolaryngology Laboratory, Department of Medical Electric Engineering of Biomedical Engineering College, Fourth Military Medical University of Chinese PLA from April, 2000 to June, 2000. Two brains were harvested from two cadavers of adult men who died in less than 12 hours before the brains were taken.INTERVENTIONS :The brains were divided into 15 samples and the Solartron 1255B frequency resoonse analyzer was used to measure the complex impedance of human brain in vitro with four-electrode measurement method in the frequency range from 0.1 Hz to 1 MHz.There were also impedance interface (1294)and self-made experimental measurement box.MAIN OUTCOME MEASURES:The resistivity frequency response,curves of real part and imaginary part of complex impedance as well as the equivalent circuit model of the complex impedance.RESULTS:The resistivity of human brain tissues was about 1 200 Ω·cm in the frequency range of 0.1-100 Hz.But it decreased to 650 Ω·cm in the frequency range of 100-1×106 Hz. The real part of complex impedance remained steady in the frequency range of 0.1-100 Hz and it decreased along with the increase of frequency in the range of 100-1×106 Hz. The absolute value of frequency response curves of the imaginary part of human brain's complex impedance presented a tendency of monotonic increase.CONCLUSION: The resistivity and the real part of complex impedance curve of human brain were in accordance with those of other tissues such as muscles, the liver, kidney and lungs. The frequency response curve of the imaginary part of human brain's complex impedance was different from that of other animal tissues (such as muscles, the liver and kidney) but was in accordance with that of rabbit brain tissues in vitro. The construction of the equivalent circuit model obtained was more complex than other models known.

BACKGROUND: Electrical impedance tomography (EIT) uses non-invasive signals to probe the human body and then detect the responses on the boundary of the body in order to reconstruct an impedance distribution inside the body. Compared to CT and MRI, EIT takes the advantages of realtime technique, lower cost and easiness for both continuous monitoring and functional imaging.OBJECTIVE: This study was designed to perform the in vivo measurement of the rabbit brain impedance frequency response before and after ischemia. And it was to verify the feasibility of EIT in brain functional imaging by ischemia brain functional imaging using EIT.DESIGN: It was a single-sample experiment.SETTING: It was conducted at the Department of Medical Electronic Engineering, Faculty of Biomedical Engineering, Fourth Military Medical University of Chinese PLA.MATERIALS: This study was conducted at the Department of Medical Electronic Engineering, Faculty of Biomedical Engineering, Fourth Military Medical University of Chinese PLA from August to September 2001 and 10 healthy rabbits were selected.METHODS: Cerebral ischemia animal model was made using carotid artery ligation. Then the in vivo measurement of the rabbit brain impedance frequency response before and after ischemia was performed.Dynamic unilateral brain blood supply was recorded using EIT imaging.curves were plot before and after ischemia in the frequency range from 0.1 Hz EIT imagingRESULTS: Nine rabbits entered the statistical analysis and one was omitimpedance increased significantly. The ratio of increasing impedance can be up to 75% at frequencies lower than 10 Hz. And in the range from 1 kHz namic imaging showed that the changes in unilateral brain blood supply is accordant with the corresponding regions having a changing impedance.CONCLUSION: The changes in brain tissue impedance before and after ischemia can be imaged and it could be used as a variable for EIT imaging.

Objective To investigate the proliferative inhibition of lens epithelial cell (LEC) by arsenic trioxide (ATO) and rhizoma curcumae (RC), in order to provide scientific basis for pursuing safe and effective natural drugs to prevent and cure after cataract. Design Experimental study. Participants Cultured Bovine LEC in vitro. Methods Changes of cellular form were observed with microscope. Different concentration of ATO (2.5, 5, 10?mol/L) and RC(5, 10, 20mg/ml) were added to the proliferative LEC separately. The effects of proliferative inhibition by ATO and RC on the LEC were measured with methyl thia-zolyl tetrazolium (MTT) assay method after 72 hours incubation. Main Outcome Measures Cellular form, Absorbance. Results Under the microscope, good growth and quantity increase were found in proliferative control group. Slowing proliferation,poor growth, and few disintegration were observed in ATO group and RC group. MTT assay: Different concentration of ATO (2.5, 5, 10?mol/L)and RC(5, 10, 20mg/ml) can significantly inhibit the proliferation of LEC and these effects were dose dependent(P

Transarterial chemoembolization (TACE) combined the embolization with chemotherapy,whose efficacy has been verified in the treatment of hepatocellular carcinoma.Factors like the incomplete embolism,the formation of collateral circulation,neoangiogenesis and the like greatly weaken the clinical efficacy of TACE in the long term.Thus,the improvement of TACE efficacy depends on the comprehensive treatment.This paper reviewed the present application status and the progress on the treatment of hepatocellular carcinoma with TACE.

OBJECTIVE: To investigate the signal transduction mechanism of curcumin in inhibiting the proliferation of bovine lens epithelial cell (LEC) induced by recombinant human epidermal growth factor (rhEGF). METHODS: There were three groups in this experiment, which were normal control group, untreated group and curcumin-treated group. Proliferation of LEC was induced by rhEGF (50 microg/L). The concentration of intracellular Ca(2+) ([Ca(2+)](i)) in LEC was measured with Fura-2/AM by spectrofluorimetry. The contents of intracellular cAMP and cGMP were assayed by radioimmunoassay. RESULTS: The [Ca(2+)]i in LEC was obviously increased in the untrated group as compared with that in the normal control group (P<0.01), and the [Ca(2+)](i) in LEC in the curcumin-treated group was highest among three groups (P<0.01). The content of intracellular cAMP in LEC was decreased while the content of intracellular cGMP was obviously increased in the untreated group as compared with those in the normal control group (P<0.01). The content of intracellular cAMP in LEC was higher in the curcumin-treated group than that in the untreated group, while the content of intracellular cGMP was lower than that in the untreated group (P<0.01). CONCLUSION: The antiproliferation effects of curcumin on LEC may relate to the regulations of multiple processes of signal transduction.

Objective To investigate the effects of the treatment of open injury and orthopedic postoperative wound infections with Vacuum Sealing Drainage.Methods Retrospective analysis of the clinical results of 32 patients with open injury or orthopedic postoperative wound infections in our hospital.Results Follow the indications and contraindications strictly and ensure right pressure,all the infection of wounds was controlled,and split skin graft survived.Without the package and pressurized fixation,the wounds healed better.Conclusion Vacuum Sealing Drainage can be considered one of the effective methods to treat the open injury or orthopedic postoperative wound infections and is worthy to be carried out as a routine.For patients with vascular rupture or defect,when there was still skin defects after vascular graft repair,as long as covered vascular anastomosis with the surrounding skin and soft tissue during the operation,there was still can use closed vacuum sealing drainage to cover the wound to prevent infection.

Objective To evaluate the role of autophagy in hydrogen-induced inhibition of apoptosis in hippocampal neurons in a rat model of orthotopic liver transplantation (OLT).Methods Fifty-six pathogen-free healthy adult male Sprague-Dawley rats,aged 8-10 weeks,weighing 220-250 g,were used in the study.Thirty-two rats were selected and assigned into 4 groups (n =8 each) using a random number table:sham operation group (group S),OLT group,hydrogen-rich saline group (group HS) and chloroquine group (group CQ).The other 24 rats severed as the donors.In group S,laparotomy was performed,and the related blood vessels were isolated.The model of OLT was established in OLT,HS and CQ groups.In group OLT,normal saline 6 ml/kg was slowly injected via the inferior vena cava at 5 min before anhepatic phase.In group HS,hydrogen-rich saline 6 ml/kg was slowly injected via the inferior vena cava at 5 min before anhepatic phase.In group CQ,autophagy inhibitor chloroquine 60 mg/kg was injected intraperitoneally at 1 h before establishment of the model,and the other treatments were similar to those previously described in group HS.At 6 h of reperfusion,the rats were sacrificed and hippocampi were isolated for determination of malondialdehyde (MDA) content and superoxide dismutase (SOD) activity,for pathological examination (with light microscope),and for detection of cell apoptosis (by TUNEL staining) and expression of autophagy-and apoptosis-related proteins caspase-3,cytochrome c (Cyt c),microtubule-associated protein 1 light chain 3 Ⅱ (LC3 Ⅱ),Beclin-1 and p53 in hippocampal tissues (by Western blot analysis).Apoptosis index (AI) was calculated.Results Compared with group S,the MDA content and AI were significantly increased,the SOD activity was decreased,and the expression of caspase-3,Cyt c,LC3 Ⅱ,Beclin-1 and p53 was up-regulated in OLT,HS and CQ groups (P＜0.05).Compared with group OLT,the MDA content and AI were significantly decreased,the SOD activity was increased,the expression of caspase-3 and Cyt c was down-regulated,and the expression of LC3 Ⅱ,Beclin-1 and p53 was up-regulated in group HS (P＜0.05).Compared with group HS,the MDA content and AI were significantly increased,the SOD activity was decreased,and the expression of caspase-3 and Cyt c was up-regulated,and the expression of LC3 Ⅱ,Beclin-1 and p53 was down-regulated in group CQ (P＜0.05).Conclusion The mechanism by which hydrogen inhibits apoptosis in hippocampal neurons is related to promotion of autophagy in a rat model of OLT.

Objective To investigate the measurement , feasibility and clinic effect of hyperthermic intraperitoneal chemotherapy (HIPEC) guided by B ultrasound in the treatment of malignant ascites from peritoneal carcinomatosis. Methods From July 2011 to June 2013, B ultrasound-guided approach was used to perform HIPEC on 36 patients affected by malignant ascites secondary to peritoneal carcinomatosis. Every patient underwent HIPEC for three times , by way of continuous circulatory perfusion into peritoneal cavity with saline at 400 ~ 600 mL/min and intraperitoneal perfusion with 5-FU mitomycin-C and cisplatin for 90 minutes with an inflow temperature of (43 ± 0.2)℃. These patients were followed up for a long term. Results Intraoperative course was uneventful in all cases. Complete clinical regression of ascites and related symptoms was achieved in all the 26 patients, partial regression achieved in 8 patients, and no curative effect achieved in 2 cases. The acquired total clinic effectiveness was 94.44%. No postoperative deaths and complication related to the procedure occurred in this study. The KPS grades of patients rose (P < 0.001), the level of tumor markers decreased, including CA199 (P < 0.001), CEA (P < 0.001), CA125 (P = 0.003). Conclusion HIPEC guided by B ultrasound appears to be a safe, feasible and effective procedure for the treatment of debilitating malignant ascites from unresectable peritoneal carcinomatosis , which would have a clinic good perspective in future.

The complex impedance measurements of human brain tissue in vitro are made by using four-electrode measurement methods in the frequency range from 0.1 Hz to 1 MHz. The Solartron 1255 B frequency response analyzer is used. The frequency response curves of the imaginary part of human brain's complex impedance do not appear as a single peak curve which other bio-tissues show, and the Cole-Cole diagram of human brain is different from the others as well. The construction of the equivalent circuit model obtained is more complex. However, these characteristics of human brain are all the same as rabbit brain's. The equivalent circuit model obtained will be helpful to constructing the equivalent circuit model of human head in the EIT researches.
Adult ; Brain ; physiology ; Electric Impedance ; Electrodes ; Humans ; In Vitro Techniques ; Male ; Models, Biological

The human skull impedance was quantitatively measured by means of Frequency Response Analyzer and its software. The impedance-frequency response curves of human skull were obtained. By analyzing the curves, we found that the characteristic frequency of human skull should be around 10 KHz.
Adult ; Electric Impedance ; Humans ; Middle Aged ; Skull ; physiology ; Time Factors