Effect of negative polarity electret on dielectric properties and hypoglycemic effects of insulin / 第二军医大学学报

Objective To study the effect of negative polarity electret on the dielectric properties and structure of insulin, and to observe the influence of electrostatic field on the hypoglycemic effect of insulin. Methods Negative polarity electrets of –500, –1 000 and –1 500 V were prepared using polypropylene film by a gate voltage corona charging system, and were used to treat insulin, respectively. The equivalent surface potential of each electret within 48 h was measured by compensation method. The relationship between the polarization of insulin and the electrostatic field was measured by the dielectric constant d33. The influence of the electrostatic field on the molecular structure of insulin was examined by nuclear magnetic resonance and gel electrophoresis. Insulin exposed to –500, –1 000 and –1 500 V negative polarity electret for 12 h was injected into the diabetic rats, and then the hypoglycemic effect of insulin were observed. Results The potential differences between the two sides of insulin solution effected by negative polarity electrets with different surface potentials were exponentially increased within 0-4 h and gradually became constant at 4-48 h. Compared with the insulin patch treated by non-electret electrostatic field, the d33 values of insulin patch effected by –500, –1 000 and –1 500 V electret for 12 h were increased by 14.7 times, 26.7 times and 45.0 times, respectively, and all tended to be stable after 12 h. The spatial structure of insulin exposed to electrostatic field did not change, but the hydrogen bond content of most perssad was decreased; the proportion of monomers of the insulin was increased, and the main structures of the insulin were monomers and dimers. Compared with the electret-free insulin treatment group, the blood glucose content of diabetic rats treated with the –500 V and –1 000 V negative polarity electrets insulin for 8 h were decreased by 50.9% and 22.1%, respectively (P<0.05). Conclusion Negative polarity electret can further improve the hypoglycemic effect of insulin.

Perioperative change in serum neutrophil gelatinase-associated lipocalin level among children with congenital heart disease and pulmonary hypertension / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the perioperative change in serum neutrophil gelatinase-associated lipocalin (NGAL) level among children with congenital heart disease (CHD) and pulmonary hypertension (PH) and its significance.</p><p><b>METHODS</b>Eighty children with CHD were divided into four groups according to pulmonary artery systolic pressure: non-PH, mild PH, moderate PH and severe PH groups. Serum NGAL levels were measured before operation, immediately after operation and 24 hours after operation. The relationship of serum NGAL level with PH and early prognosis was analyzed.</p><p><b>RESULTS</b>The mild, moderate and severe PH groups had significantly higher serum NGAL levels than the non-PH group, and the severer the PH, the higher the serum NGAL level (P<0.01). All groups showed significant decreases in serum NGAL levels after operation (P<0.01). Serum NGAL level was positively correlated with the degree of PH and length of stay in the intensive care unit (P<0.01).</p><p><b>CONCLUSIONS</b>Serum NGAL level increases in children with CHD and PH, and it gradually decreases after operation for closing the abnormal shunt. Serum NGAL level may be used as a serological indicator for evaluating the degree of PH and surgical outcome.</p>

Promoting effect of positive polarity electret combined with azone on transdermal penetration of cyclosporin A / 第二军医大学学报

Objective To study the effects of positive polarity electret combined with different concentrations of azone in promoting the transdermal delivery of cyclosporin A, so as to explore the feasibility and the rule of electret combined with chemical enhancers in promoting transdermal delivery. Methods Cyclosporin A was used as the model drug in the present study. Positive polarity electret was prepared using corona charge technique. Franz diffusion cell system and HPLC techniques were applied to investigate the roles of positive polar electret, azone of different concentrations and their combination in promoting penetration of cyclosporin A in vitro. Results Satisfactory penetration promoting effects for cyclosporin A was observed in excised skin 24 h after exposure to +500 V, +1 000 V and +2 000 V electret. Compared to the control group, 1%, 3%, and 5% azone promoted the steady-state penetration rates of cyclosporin A by 6. 72, 2. 11, and 1. 43 folds after 24 h exposure. Combination of +1 000V electret plus 1% azone showed better penetration promoting effect than other combinations, but electret with different positive charges and different concentrations of azone showed no synergistic effect in promoting cyclosporin A penetration. Conclusion Positive polarity electret has a penetration promoting effect for transdermal delivery of cyclosporin A. Positive polarity electret and azone show no synergistic effect on promoting penetration of cyclosporin A.

Preventive and therapeutical effects of N-acetylcysteine on selenite-induced cataract in vivo / 中华实验眼科杂志

Background The mechanism of both selenite-induced cataract and age-related cataract is oxidative damage.N-acetylcysteine (NAC) is one of the effective antioxidants,but the literature is little about the preventive and treating effects of NAC on cataract. Objective This study attempted to investigate the preventive and therapeutical effects of NAC on the selenite-induced cataract,and to discuss the possible mechanism. Methods Sixty 10-day-old clean SD rats were randomly divided into normal control group-1,normal control group-2,selenite-induced cataract group,NAC preventive group,NAC+normal saline group and NAC treatment group.Selenite cataract models were induced by subcutaneous injection of 3.46 mg/kg sodium selenite once daily for three days.The rats of NAC preventive group received the intraperitoneal injection of 2 mmol/L NAC 30 minutes before the injection of sodium selenite once daily for 6 days.In NAC treating group,2 mmol/L NAC was intraperitoneally injected 1 day after the injection of sodium selenite for 30 days,and the normal saline solution was injected at the same method in the NAC+normal saline group.Lens opacification was graded according to LOCS Ⅲ criteria.Histopathological change of lens epithelium was examined under a light microscope after hemotoxylin and eosin staining,and the ultrastructure was observed under the scanning electron microscope.The expression of caspase-3 in lens was assayed using immunochemistry.The levels of superoxide dismutase ( SOD ),malonaldehyde ( MDA ) in rat lens were detected respectively in corresponding time points.The use of the experimental animals complied with the Regulation for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Committee. Results In 7 days after experiment,lenses were completely clear in the normal control group.Lens opacification of Ⅴ grade was found in 11 eyes in selenite cataract model group,but no lens opacification of Ⅴ grade was seen in NAC preventive group,showing a significant difference(x2 =40.000,P＜0.05 ).In 30 days after experiment,Ⅳ- Ⅴ grades of cataracts were found in 20 eyes both in NAC + normal saline group and NAC treating group (x2=0.153,P＞ 0.05 ).Histopathological examination showed that lens structure was normal,and the separation between LECs and anterior capsule,the rupture of cellular membrane,deformation of cellular nuclei and the feature of lens fiber were seen in selenite cataract group,but the damage of lens was mild in the NAC preventive group.Ultrastructure of lens was obviously abnormal in selenite cataract group,NAC+normal saline group and NAC treating group.Expressions of caspase-3 and SOD in lens were significantly lower,but that of MDA was significantly higher in the selenite cataract group than the normal control group (P＜0.05) ;while those of the NAC preventive group were significantly different from selenite cataract group(P＜0.05).No significant difference was found in the expressions of caspase-3 and the levels of SOD and MDA between NAC+normal saline group and NAC treating group (P＞0.05 ). Conclusions Selenite can induce the apoptosis of LECs.NAC can evidently postpone formation of selenite cataract by increasing the activity of SOD,decreasing the level of MDA and the expression of caspase-3.However,NAC could not reverse selenite-induced lens damage.

Experimental study of ginsenoside Rb1 on herpes simplex virus-1 infection for protecting nerves / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the action mechanism of ginsenoside Rb1 (GRb1) on protecting herpes simplex virus-1 (HSV-1) infected nerves by studying its inhibitory effects on abnormal changes of apoptosis and nerve growth factor (NGF) mRNA expression in HSV-1 infected human glioma cells U251.</p><p><b>METHODS</b>The inhibitory effects of GRb1 on HSV-1 induced abnormal apoptosis of U251 cells were detected using MTT colorimetry and flow cytometry. The NGF mRNA expressions in different treatment groups were detected using semiquantitative RT-PCR.</p><p><b>RESULTS</b>(1) In 400 microg/mL GRb1 + HSV-1 group, MTT value was higher than HSV-1 group at 24, 36, and 48 h after infection (P < 0.05). (2) Cytopathic effects (CPE) were observed in HSV-1 group at 36 h after infection. In 400 microg/mL GRb1 + HSV-1 group merges increased at 36 h after infection, but most cells were in normal shapes. (3) Results of flow cytometry showed that the cell apoptosis rate was lower in 400 microg/mL GRb1 + HSV-1 group than in the HSV-1 group at24 and 36 h after infection (P < 0.05). (4) Results of RT-PCR showed that in 400 microg/mL GRb1 + HSV-1 group, NGF mRNA expressions decreased at 6-12 h after infection (P < 0.05), but it increased at 24, 36, and 48 h after infection, and was obviously higher than that in the HSV-1 group (P < 0.05).</p><p><b>CONCLUSIONS</b>GRb1 at an appropriate concentration could inhibit abnormal cell apoptosis and changes of NGF mRNA expressions in HSV-1 infection. Therefore, we inferred that GRb1 could protect nerves possibly through up-regulating NGF mRNA expressions and inhibiting apoptosis.</p>

Effect of perioperative glucose-insulin-potassium infusions on the prognosis in patients undergoing coronary artery bypass grafting: a meta-analysis / 中华外科杂志

<p><b>OBJECTIVE</b>To assess the effect of perioperative glucose-insulin-potassium (GIK) infusions on the prognosis in patients undergoing coronary artery bypass grafting.</p><p><b>METHODS</b>Electronic databases including Cochrane library (Issue 3, 2011), Pubmed, EMbase, Highwire, CBM and CNKI were searched. A meta-analysis of all randomized controlled trials (RCTs) comparing GIK with control in coronary artery bypass grafting was performed. Study selection and meta-analysis were conducted which according to the Cochrane Handbook for systematic reviews. Date were extracted from these trials by 3 reviewers independently and analyzed by RevMan5.0 software.</p><p><b>RESULTS</b>A total of 9 RCTs including 1029 patients were assessed in this study. GIK infusion was associated with significantly fewer perioperative myocardial infarctions (RR = 0.59, 95%CI: 0.38 - 0.91, P = 0.02), less inotropic support requirement (RR = 0.44, 95%CI: 0.35 - 0.56, P < 0.01), and increase the incidence of postoperative atrial fibrillation (RR = 1.23, 95%CI: 1.05 - 1.43, P = 0.009).</p><p><b>CONCLUSIONS</b>GIK significantly reduces myocardial injury and improves cardiac function in patients undergoing coronary artery bypass grafting, but also increases the incidence of postoperative atrial fibrillation.</p>

Experimental study on adipose-derived stem cells combined with acellular dermal matrix particles for vocal fold injection / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To explore the feasibility of adipose-derived stem cells (ASC) combined with micronized acellular dermal matrix (MADM) for vocal cord injection.</p><p><b>METHODS</b>The adipose-deprived stem cells were harvested from rabbit adipose tissue in vitro. The 3rd generation of ASC was labeled with DiI (1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate) and cultured with MADM to form a complex. The adhesion of ASC to MADM was observed by fluorescence microscope and electron microscope. The proliferation of ASC on MADM was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy methoxyphenyl)-2-(4-sulfonyl)-2H-tetrazolium, inner salt (MTS). Three days after the culture, the complex was mixed with appropriate amount of collagen, and then injected into the unilateral vocal cord of the rabbit. The animals were sacrificed 2, 4, 8 weeks after injection, the survival time and distribution of ASC in vocal fold were tested, and the responses of vocal cord to ASC-MADM and the degradation of MADM were observed.</p><p><b>RESULTS</b>The ASC adhered to MADM and grew well (P < 0.05 or < 0.01), showing good compatibility with MADM in vocal cord tissue. The complex of ASC-MADM could be injected into the rabbit vocal cords, while no adverse reactions was observed in the vocal cord by endoscope, frozen section and HE staining. ASC could survive for 8 weeks in vocal cords, and no inflammatory cell infiltration was observed.</p><p><b>CONCLUSIONS</b>MADM is an ideal scaffold material and shows perfect compatibility with ASC which can adhere and proliferate well on it. The complex of ASC-MADM can be injected into the vocal cord and can survive. There is no adverse reaction in vocal cords.</p>

The isolation, cultivation and identification of laryngeal mucosal mesenchymal stem cells / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the presence of mesenchymal stem cells (MSC) in laryngeal mucosa, and to seek for the method to isolate, cultivate and identify these cells.</p><p><b>METHODS</b>Normal laryngeal mucosa was obtained from patients with laryngeal carcinoma during surgery, and the generating mesenchymal cells was obtained by digestive method. The cell growth curve was evaluated by 3-(4.5-methylthiazol-2yl)-2.5-diphenyltetrazolium bromide (MTT) assay. Colony forming cell assay was used to screen different morphologic colonies and evaluate clone formation ability. Flow cytometry was performed for the expression of the cells of the 4th passage surface marker profiles. Multiple differentiation potentials were confirmed by adipogenic, osteogenic and neural lineages induction.</p><p><b>RESULTS</b>MTT assay and colony forming cell assay showed that laryngeal mucosa MSC had a relatively rapid proliferation capacity and a relatively high clone formation capacity (clone formation rate 7.1%). Flow cytometry analysis revealed that the laryngeal mucosa MSC were positive for CD29 (16.9%), CD44 (97.4%), CD90 (89.5%), CD105 (85.9%), CD146 (2.5%) and stro-1 (20.4%), but negative for CD34 (1.2%) and CD45 (0.8%). Laryngeal mucosa MSC undergone adipogenic, osteogenic and neural lineages induction were positive for oil red staining, alizarin red staining and S100 staining respectively, which suggested that laryngeal mucosa MSC could differentiate into adipogenic, osteogenic and neural lineages.</p><p><b>CONCLUSION</b>This study demonstrated that MSC with rapid proliferative capacity and multiple differentiation potential could be obtained from lamina propria of laryngeal mucosa.</p>