1.A qualitative study of in vivo pulsed electric field distribution model in rabbit liver tissues.
Xiaojun YANG ; Li'na HU ; Jun LI ; Caixin SUN ; Chenguo YAO ; Lan XIONG ; Shibin WANG
Journal of Biomedical Engineering 2005;22(3):497-500
Pulsed electric fields (PEFs) with fixed frequency, width and gradually increased peak value of voltage was applied to 30 healthy rabbit liver tissues. The specific aims were to explore the feasibility of establishing a model of in vivo PEFs distribution in healthy rabbit liver tissues and to provide important references for clinical electrochemotherapy and for electrotransfer. Repeated experiment and self-comparison statistics design were implemented. The rabbit underwent the experiment under intravenous anesthesia and their liver tissues, after exposure to PEFs, were sent for HE staining. Necrotic borderline was visible 3 days after PEFs application, the necrotic shape of concentric circle was evident around the electrodes under optical microscope at lower voltage, as voltage increasing, two necroses in the shape of concentric circle gradually enlarged; nuclei with chromatin condensation, fragmentation and lysis alterations were seen in the middle region between the needles; concentric circles changed into ellipse fusiform and finally overlaped each other forming irregular necrosis contours. Cell cavitation and tissues ischemia were also observed within electric field. The shape of tissue necrosis from the experiment was noted to correlate with theoretic simulation of electric field distribution. Therefore, rabbit liver tissues can be a good carrier for in vivo modeling of electric field distribution when the lethal effects of PEFs in tissues are investigated. PEFs also show safety for the surrounding normal tissue while causing damage or injury to the target area therapeutically.
Animals
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Electricity
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adverse effects
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Electrochemotherapy
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Liver
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pathology
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Male
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Models, Theoretical
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Necrosis
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Rabbits
2.Electrostatic protection of oxygen pressure cabins.
Zhi-Man ZHENG ; Jin-Feng LIU ; Xiao-Shan HUANG ; Wei-Chun LIU
Chinese Journal of Medical Instrumentation 2005;29(2):138-139
This paper describes electrostatic harms to oxygen pressure cabins and protection measures which should be taken.
Fires
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prevention & control
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Humans
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Humidity
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Hyperbaric Oxygenation
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Oxygen Inhalation Therapy
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instrumentation
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Static Electricity
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adverse effects
3.Analysis of 4 Cases of Electrocution due to Direct Current Electronic Hunter.
Long Long ZHU ; Fang TONG ; Yue LIANG ; Ten Zin LOPSONG ; Wei Sheng HUANG ; Yu Luo LIU ; Yi Wu ZHOU
Journal of Forensic Medicine 2019;35(5):592-595
Objective To summarize the characteristics of cases of electrocution due to direct current (DC) electronic hunter, and to provide references for forensic identification. Methods Four cases of electrocution due to DC electronic hunter were collected. Statistical analysis was carried out from the perspective of the scene and electric marks distribution, damage characteristics and histopathological changes. Results All the 4 cases of electrocution were accidental events. There were multiple electric marks, most of which were located in the lower limbs with serious damage. Some strip type electric marks were visible. Conclusion The distribution, morphological characteristics and severity of the electric marks caused by DC electronic hunter are different from those of the ordinary low-voltage alternating current damage. It is alerting that there would be actions of destroying the scene and abandoning the corpse in such cases.
Cadaver
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Electric Injuries/pathology*
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Electricity/adverse effects*
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Fatal Outcome
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Forensic Pathology/methods*
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Humans
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Lower Extremity
4.Changes in the expression of large-conductance calcium-activated potassium channels in dorsal root ganglion neurons after electrical injury in rats' sciatic nerves and its influence on sensory conduction function.
Guangning WANG ; Xueyong LI ; Xiaoli XU ; Pan REN
Chinese Journal of Burns 2016;32(6):363-369
OBJECTIVETo study the changes in the expression of large-conductance calcium-activated potassium (BKCa) channels in dorsal root ganglion (DRG) neurons after electrical injury in rats' sciatic nerves and its influence on sensory conduction function.
METHODSOne-hundred and thirty-six adult SD rats were divided into normal control group, sham electrical injury group, and 75, 100, 125 V electrical injury groups according to the random number table, with 8 rats in normal control group and 32 rats in each of the rest 4 groups. Rats in normal control group were routinely fed without any treatment. Blunt dissection of the sciatic nerves of left hind leg of rats was performed in sham electrical injury group, while sciatic nerves of left hind leg of rats in electrical injury groups were electrically injured with corresponding voltage. Eight rats of normal control group fed for one week, and 8 rats from each of the rest four groups on post injury day (PID) 3 and in post injury week (PIW) 1, 2, 3 respectively were collected to detect the paw withdrawal mechanical threshold (PWMT). In addition, rats of 100 V electrical injury group in PIW 1 were collected and intrathecally injected with NS1619 after former PWMT detection, and PWMT was detected per 30 minutes within three hours post injection. The rats in each group at each time point were sacrificed after PWMT detection. The DRG of L4 to L6 segments of spinal cord was sampled to observe the BKCa channels distribution with immunohistochemical staining and to detect the protein and mRNA expressions of BKCa channels with Western blotting and reverse transcription-polymerase chain reaction respectively. Data were processed with one-way analysis of variance, analysis of variance of factorial design, and SNK test.
RESULTS(1) The PWMT values of rats in 75 and 100 V electrical injury groups on PID 3 and in PIW 1, 2, 3 were (5.8±0.6), (5.0±0.8), (4.2±0.3), (5.9±1.1) g; (5.3±1.3), (5.9±2.0), (4.5±2.7), (4.3±1.3) g, respectively, which were significantly lower than the value (s) in normal control group [(11.2±2.0) g] and sham electrical injury group [respectively (11.3±2.1), (12.0±2.0), (11.1±1.6), (10.3±2.1) g, with P values below 0.05]. The PWMT values of rats in 125 V electrical injury group decreased obviously on PID 3 and in PIW 1 [(6.1±1.6) and (5.7±1.7) g] as compared with the value (s) in normal control group and sham electrical injury group, and they were obviously increased in PIW 2 and 3 [(26.7±3.3) and (21.7±3.4) g] as compared with the value (s) of the rest 4 groups (with P values below 0.05). The PWMT of 100 V electrical injury group in PIW 1 firstly increased and then decreased within three hours post injection, which increased significantly at post injection minutes 30, 60, 90, 120 as compared with that before intervention [respectively (8.5±0.8), (9.7±1.2), (11.0±1.5), (8.6±0.8) g, with P values below 0.05]. (2) The positive expression of BKCa channels in large amount was observed in the cytoplasm and cytomembrane of neurons on the DRG of rats in normal control group and sham electrical injury group at each time point. The positive expression of BKCa channels in the cytoplasm and cytomembrane of neurons on the DRG of rats decreased over time in electrical injury groups, which was most obvious in 125 V electrical injury group. (3) There were no statistically significant differences in the protein expression of BKCa channels in DRG of rats among the five groups on PID 3 (with P values above 0.05). Compared with those in normal control group (0.477±0.027, 0.521±0.034, 0.475±0.022) and sham electrical injury group (0.511±0.025, 0.489±0.025, 0.483±0.032) in PIW 1, 2, 3, the protein expressions of BKCa channels in DRG of rats in 75, 100, 125 V electrical injury groups were decreased significantly (0.274±0.026, 0.202±0.019, 0.285±0.033; 0.253±0.022, 0.233±0.024, 0.203±0.017; 0.092±0.017, 0.095±0.021, 0.087±0.016, with P values below 0.05). The protein expressions of BKCa channels in DRG of rats in 125 V electrical injury group in PIW 1, 2, 3 were obviously lower than those in 75 and 100 V electrical injury groups (with P values below 0.05). (4) The mRNA expression levels of BKCa channels in DRG of rats in 75, 100, 125 V electrical injury groups on PID 3 and in PIW 1, 2, 3 were 0.326±0.021, 0.238±0.019, 0.291±0.022, 0.364±0.018; 0.264±0.020, 0.293±0.017, 0.243±0.023, 0.295±0.021; 0.134±0.023, 0.089±0.017, 0.074±0.018, 0.087±0.020, respectively, significantly decreased as compared with the level (s) in normal control group (0.581±0.051) and sham electrical injury group (0.603±0.045, 0.586±0.032, 0.614±0.045, 0.572±0.038), with P values below 0.05. The mRNA expression levels of BKCa channels in DRG of rats in 125 V electrical injury group at each time point were lower than those in 75 and 100 V electrical injury groups (with P values below 0.05).
CONCLUSIONSThe electrical injury in sciatic nerves results in reduction of the BKCa channels expression in rat's DRG of corresponding spinal segments, which plays a role in the pathological process of sensory conduction dysfunction.
Animals ; Blotting, Western ; Electricity ; adverse effects ; Ganglia, Spinal ; metabolism ; Large-Conductance Calcium-Activated Potassium Channels ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries
5.Multilayer Coating of Tetrandrine-loaded PLGA nanoparticles: Effect of surface charges on cellular uptake rate and drug release profile.
Rui MENG ; Ke LI ; Zhe CHEN ; Chen SHI
Journal of Huazhong University of Science and Technology (Medical Sciences) 2016;36(1):14-20
The effect of surface charges on the cellular uptake rate and drug release profile of tetrandrine-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TPNs) was studied. Stabilizer-free nanoprecipitation method was used in this study for the synthesis of TPNs. A typical layer-by-layer approach was applied for multi-coating particles' surface with use of poly(styrene sulfonate) sodium salt (PSS) as anionic layer and poly(allylamine hydrochloride) (PAH) as cationic layer. The modified TPNs were characterized by different physicochemical techniques such as Zeta sizer, scanning electron microscopy and transmission electron microscopy. The drug loading efficiency, release profile and cellular uptake rate were evaluated by high performance liquid chromatography and confocal laser scanning microscopy, respectively. The resultant PSS/PAH/PSS/PAH/TPNs (4 layers) exhibited spherical-shaped morphology with the average size of 160.3±5.165 nm and zeta potential of-57.8 mV. The encapsulation efficiency and drug loading efficiency were 57.88% and 1.73%, respectively. Multi-layer coating of polymeric materials with different charges on particles' surface could dramatically influence the drug release profile of TPNs (4 layers vs. 3 layers). In addition, variable layers of surface coating could also greatly affect the cellular uptake rate of TPNs in A549 cells within 8 h. Overall, by coating particles' surface with those different charged polymers, precise control of drug release as well as cellular uptake rate can be achieved simultaneously. Thus, this approach provides a new strategy for controllable drug delivery.
Antineoplastic Agents, Phytogenic
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administration & dosage
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chemistry
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Benzylisoquinolines
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administration & dosage
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chemistry
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Cell Line, Tumor
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Drug Liberation
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Humans
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Lactic Acid
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chemistry
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Nanoparticles
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adverse effects
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chemistry
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metabolism
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Polyamines
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chemistry
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Polyglycolic Acid
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chemistry
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Polystyrenes
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chemistry
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Static Electricity