The AC impedance of human hepatoma SMMC-7721 cells were measured in our laboratory by Agilent 4294A impedance analyzer in the frequency range of 0.01-100 MHz. And then the effect of hematocrit on electrical impedance characteristics of hepatoma cells was observed by electrical impedance spectroscopy, Bode diagram, Nyquist diagram and Nichols diagram. The results showed that firstly, there is a frequency dependence, i.e., the increment of real part and the imaginary part of complex electrical impedance (δZ', δZ"), the increment of the amplitude modulus of complex electrical impedance (δ[Z *]) and phase angle (δθ) were all changed with the increasing frequency. Secondly, it showed cell volume fraction (CVF) dependence, i. e. , the increment of low-frequency limit (δZ'0, δ[Z*] 0), peak (δZ"(p), δθ(p)), area and radius (Nyquist diagram, Nichols diagram) were all increased along with the electric field frequency. Thirdly, there was the presence of two characteristic frequencies: the first characteristic frequency (f(c1)) and the second characteristic frequency (f(c2)), which were originated respectively in the polarization effects of two interfaces that the cell membrane and extracellular fluid, cell membrane and cytoplasm. A conclusion can be drawn that the electrical impedance spectroscopy is able to be used to observe the electrical characteristics of human hepatoma cells, and therefore this method can be used to investigate the electrophysiological mechanisms of liver cancer cells, and provide research tools and observation parameters, and it also has important theoretical value and potential applications for screening anticancer drugs.
Carcinoma, Hepatocellular ; Cell Line, Tumor ; Cell Membrane ; Cytoplasm ; Electric Impedance ; Electrophysiological Phenomena ; Humans ; Liver Neoplasms ; Membrane Potentials

[Abstract ] Objective The spleen plays an important role in brain ischemia-induced cerebral injury.This study aimed to ex-plore the correlation of the spleen mass index with the neurological function scores and infarction volume following permanent occlusion of the middle cerebral artery ( pMCAO) in rats. Methods Thirty male SD rats were equally randomized into a sham operation, a 3-day brain ischemia, and a 7-day brain ischemia group.The pMCAO model was established by ligation in the right brain of the rats. Neurological function scores were obtained with the Longa 5-Point Scale at 0, 3, and 7 days after modeling, and at 3 and 7 days, the spleen mass index was calculated, the infarction volume measured by TTC, and brain histopathological changes evaluated by HE stai-ning. Results Compared with the 7-day ischemia group, the 3-day ischemia rats showed significantly reduced spleen mass index ([1.62 ±0.58] vs [0.87 ±0.59] mg/g) and increased neurological function score (1.00 [1.00, 1.25] vs 2.00 [1.75, 2.25]) and infarct volume ([18.67 ±7.92] vs [36.20 ±14.92]%) (all P<0.05).An extremely significant decrease was found in the spleen mass index of the 3-day ischemia rats in comparison with that of the animals in the sham operation group ([1.90 ±0.22] mg/g) (P<0.01).HE staining revealed more obvious pathological injury of the cerebral cortex in the 3-day than in the 7-day group.The spleen mass index was negatively correlated with the neurological dys-function score (r=-0.851, P=0.019) and infarction volume (r=-0.717, P =0.013). Conclusion In pMCAO rats, measure-ment of the spleen mass index contributes significantly to the preven-tion and improvement of ischemia-induced cerebral injury.

Objective To explore the effect of carnosine in the expression of B cell lymphomal/leukemia-2 (bcl-2) and bcl-2-associated X protein (bax) after focal cerebral ischemia in rats. Methods Thirty male SD rats (SPF scale) were ran?domly divided into 3 groups:sham-operated group, model group and carnosine treated group (n=10 for each group). The mid?dle cerebral artery occlusion model (MCAO) was induced in model group and carnosine treated group. Rats were received carnosine [1 000 mg/(kg·d), orally] in carnosine treated group, and the other rats were received the same volume of normal sa?line (NS) in shame-operated group and model group. The neurological deficit score was used to evaluate the neurological function at 24 h and 72 h after MCAO. Morphological changes were observed by HE staining. TCC staining was used to label infarct volume, and immunohistochemistry was used to detect the expression of bcl-2 and bax. Results Compared with model group, the score of neurological function and infarct volume were significantly declined in carnosine treated group at 72 h after injury (P<0.05 or P<0.01). The changes of ischemic impairment were lighter in carnosine treated group than that of model group. Compared with sham-operated group, the expression levels of bcl-2 and the ratio of bcl-2/bax were de?creased while the expression of bax was increased in model group (P<0.05). Compared with model group, carnosine could sig?nificantly increase the expression of bcl-2 and the ratio of bcl-2/bax, and reduce the expression of bax (P<0.01 or P<0.05). Conclusion Carnosine can enhance bcl-2 expression, decrease bax expression and increase the ratio of bcl-2/bax, which is likely to be one of the mechanisms of neuroprotection.

Dysfunction after stroke caused great burden to patients,families and society,early rehabilitation training is an effective and economic way to improve the function.Motor relearning program (MRP) is a popular rehabilitation method in recent years.In this reviw,the concept and characteristics of MRP are introduced firstly,then we summarize three elements in implementation of MRP,including time,strength and environment,and finally,the application of MRP in clinical stroke patients is emphasized.

Objective To investigate the effects of different therapeutic strategies on recurrence of postoperative Crohn's disease (CD) patients.Methods From September 2009 to September 2014,85 CD patients with intestinal resection were enrolled.The clinical features and maintenance therapeutic medication were retrospectively analyzed.The patients were divided into non-treatment group (induding continuously or cumulatively taking medicine less than three months),5-aminosalicylic acid (5-ASA) group and immunosuppressant agents group (including azathioprine,methotrexate and thalidomide).Kaplan-Meier method was performed to compare the recurrence rate in postoperative CD with different therapeutic medication and the risk factors of postoperative recurrence were also analyzed.Results Among 85 CD patients,there were 32,21 and 32 patients in non-treatment group,5-ASA group and immunosuppressive agents group,respectively.After surgery,the one year accumulated clinical recurrence rate of immunosuppressant agents group was 12.5％ (4/32),which was significantly lower than that of non-treatment group (56.3％,18/32) and 5-ASA group (38.1％,8/21),and the differences were statistically significant (x2 =12.250,P＜0.01;x2 =4.102,P =0.043).After surgery,the two years accumulated clinical recurrence rate of immunosuppressant agents group was 12.9 ％ (4/31),which was significantly lower than that of non-treatment group (75.9％,22/29) and 5-ASA group (47.6％,10/21),and the differences were statisitcally significant (x2 =17.840,P＜0.01;x2 =6.597,P=0.010).After operation,the one year accumulated endoscopic recurrences rates of non-treatment group,5-ASA group and immunosuppressant agents group were 39.1％ (9/23),5/16 and 34.6％ (9/26),respectively;while the two year accumulated endoscopic recurrence rates were 59.1％ (13/22),6/16 and 44.0％ (11/25),respectively.However,there was no statistically significant difference among the groups (all P＞0.05).Penetrating lesion was an risk factor of postoperative clinical recurrence in CD patients (x2 =4.963,P=0.026,oddsratio (OR) =2.221,95 ％ confidence interval (CI) 1.121 to 5.775).Conclusions Immunosuppressive agents rather than 5-ASA have remarkable effects in preventing postoperative clinical recurrence in CD patients.Postoperative clinical recurrence is more likely to happen in patients with penetrating lesions.

Objective:To determine the valproate concentration in plasma of epilepsy patients by HPLC, and compare with the re-sults of chemiluminescence microparticle immunoassay ( CMIA) to evaluate the consistency of the two methods. Methods:HPLC and CMIA was respectively applied to determine the plasma concentration of valproate in 230 epileptic patients. The correlation of the two methods was studied by Passing-Bablok regression and Bland-Altman method. Results:The regression equation of the determination re-sults of HPLC (Y) and CMIA (X) was Y=1. 069 7X+2. 338 2 (R2 =0. 969, n=230), which showed promising correlation. Bland-Altman analysis showed that the consistency of the two methods was poor, and the values of HPLC were higher. Conclusion: HPLC and CMIA used for the determination of valproate plasma concentration show good correlation. However, the consistency is poor and there is system error. In the clinical treatment, adjustment and choice should be paid more attention.

Animals ; Cochlea ; pathology ; Female ; Guinea Pigs ; Hyperlipidemias ; pathology ; physiopathology ; Male ; Otoacoustic Emissions, Spontaneous

Anti-Bacterial Agents ; pharmacology ; Child ; Humans ; Macrolides ; pharmacology ; Microbial Sensitivity Tests ; Mycoplasma pneumoniae ; drug effects

Objective To evaluate the clinical value of spectral CT monochromatic imaging in improvement of imaging quality of bronchial arteries.Methods We retrospevtively analyzed the chest CT images in 38 patients who underwent the contrast-enhanced spectral CT.These images included a set of 140 kVp polychromatic images and default 70 keV monochromatic images.Using a standard Gemstone Spectral Imaging (GSI)viewer at an advanced workstation (AW4.6),an optimal energy level (in keV)for obtai-ning the best CNR of the bronchial artery could be automatically obtained.The SNR,CNR and objective imaging quality score for these 3 imaging sets (140 kVp,70 keV and optimal energy level)were obtained and compared with one-way ANOVA .Results The optimal energy levels for obtaining the best CNR were (62.58±2.74)keV.The SNR of the 140 kVp polychromatic images,70 keV monochromatic images,and the optimal keV monochromatic images were 1 6.44±5.85,20.96 ±8.32 and 24.91 ±9.91,the CNR were 13.30±5.45,1 7.25±6.97 and 20.67±8.62,and the subjective imaging quality scores were 1.97 ±0.82,3.24±0.75 and 4.47±0.60,respectively,exhibiting significant differences among groups (F =10.1 7,10.1 7 and 1 1 1.12,P <0.00).The optimal monochromatic group was superior to the 70 keV group and the 140 kVp mixed-energy group.Conclusion Monochromatic images at approximately 62 keV in dual-energy spectral CTA yields the best CNR and highest diagnostic confidence for imaging bronchial ar-teries,which may improve imaging quality for imaging bronchial arteries.

Objective To compare the virtual non-enhanced chest CT (VNCT)generated from spectral CT with conventional non-enhanced chest CT in patients with lung disease in terms of CT number accuracy and image quality.Methods A total of 30 patients with lung disease proved by pathology underwent the conventional non-enhanced thoracic CT and contrast enhanced CT with spectral imaging mode in arterial phase (AP)and venous phase (VP).The VNCT images were reconstructed based on the enhanced spectral CT imaging data.The mean CT number,signal to noise ratio (SNR)for the lesions and image quality score were obtained and compared between the true non-contrast CT (TNCT)and the VNCT (including AP and VP)with paired t test.Results The mean±standard deviation for CT number were (38.74±5.17)HU,(39.08±5.07)HU and (38.96± 5.18)HU for TNCT,VNCT at AP and VNCT at VP,respectively, with no statistical difference (P>0.05).All 3 sets of images demonstrated acceptable image quality,even though there were statistically significant differences in the SNR value and image quality score.The mean ± standard deviation values for SNR were 4.74±0.42 with TNCT, 3.79 ± 0.5 1 with VNCT at AP and 3.77 ± 0.39 with VNCT at VP (P <0.05),and the image quality scores were 5.00 ±0.00 with TNCT,4.17±0.65 with VNCT at AP and 4.17±0.53 with VNCT at VP (P<0.05).Conclusion In patients with lung disease,the vir-tual non-enhanced CT images generated from spectral CT provide accurate CT numbers for lesions and acceptable image quality com-pared with the true non-contrast CT.VNCT may be used to replace TNCT to improve work flow and reduce radiation dose.