AIM:To study chromosome aberration due to ethidium bromide (EB), a heterocyclic organic compound and an organic fluorescence dye commonly used in biochemical experiment, and to help further understanding the molecular mechanism of tumor or cancer induced by EB and other heterocyclic organic compounds. METHODS: The toxicity action of EB was evaluated from three aspects including DNA, chromosome and embryo stem cells (ESCs) using atomic force microscopy (AFM), and thereinto, the morphology structural difference of ESCs treated with two EB doses was also valuated. RESULTS: The morphological structures of DNA, chromosome and ESCs were dramatically damaged. The average height of DNA decreased 0.5 nm; chromosomal arms were ruptured from centromere location; molecules of cellular membrane congregated and loop-like structure formed, and ES cell masses were collapsed and became dead after large EB doses treatment and mesh-like morphological structure was discernable. CONCLUSION: The toxicity action of EB is strong and destroys the surface structure of DNA and chromosome. EB induces structural aberration of ES cellular membrane and cell death. The results indicate that the action of EB is externalized at gene level and cell level, which is important to study the carcinogenicity of EB.

Gold nanorods is a capsule-shaped gold nanoparticles. Gold nanorods give rise to two absorption peaks corresponding to their plasmonic modes, transverse mode and longitudinal mode, corresponding to light absorption and scattering along the short and long axis, respectively. The longitudinal surface plasmon resonance can be tuned by adjusting their aspect ratio from the visible to the NIR region and extremely sensitive to changes in the dielectric properties of the surroundings including solvents, adsorbates, and the interparticle distance of the gold nanorods. This unique optical property of gold nanorods opens up fascinating applications in biological and chemical sensors. Optical properties and biomedical application of gold nanorods are introduced, and its future research prospects are discussed.

Objective To study the effects of surfactants on conformation of hemoglobin and further to understand the potential impact of surfactants in environment on human health. Methods The changes of the conformation of hemoglobin induced by cation and anion surfactants were investigated with four methods, such as synchronous fluorescence spectra, UV, electrochemistry and atom force microscope. Results The changes of the conformation of hemoglobin induced by anion surfactant were obvious but were not by cation surfactant. Conclusion Sodium lauryl sulphate, an anion surfactant, may change the conformation of hemoglobin.

Atomic force microscope(AFM) has one important feature that it is used to scan the samples with non-modified and modified probes to obtain sample appearance,and force-distance curve at certain point,based on which the adhesion,bond force and mechanical properties of the sample can be obtained.Until recently,the application of the AFM to measure the mechanical properties of biological sample is very extensive,which is significant in biomedicine and clinical medicine.This paper introduced the force curve theory of AFM,and reviewed the application of AFM to measure the mechanical properties of biological sample including elasticity,adhesion,stiffness,the interaction between antibody and antigen of the cell.In addition,we prospected the application and development of AFM to analyze cell mechanical properties.

BACKGROUND:The main symptoms of herpes zoster (HZ) manifest as pain and skin eruption and the pain, when treated inadequately, may proceed to become post herpetic neuralgia (PHN) which has progressively increasing incidence with age.OBJECTIVE: To observe the effect of combined therapy of super laser and Durogesic patch (transdermal fentanyl) in the treatment of elderly patients with herpes zoster and diabetes.DESIGN: Randomized controlled observation.SETTING: The First Affiliated Hospital of Jinan University.PARTICIPANTS: Thirty (14 males and 16 females) elderly patients of age 62-83 years with concurrent herpes zoster (duration 6-14 days) and diabetes who had received the conventional dermatological and medication treatment but still had persistent pain were selected form the First Affiliated Hospital of Jinan University from 2003 to 2006. All elderly patients were randomly divided into 3 groups with 10 in each group.METHODS: ① Super Lizer group (SL Group): Patients were received Super Lizer (linear polarized near-infrared light) therapy once a day for 15 days. ② Durogesic patch group (DR Group): Patients were received 2.5 mg Durogesic patch once for every 3 days. ③ Combined group (SL+ DR Group): Patients were received both the Super Lizer therapy and the Durogesic patch for 15 days.MAIN OUTCOME MASURES: All patients received the assigned treatment for 3 days and VAS was evaluated before and at the 3rd, 15th day during treatment, also at 7th day after termination of treatment. Visual analogue scales were used to assess the degree of pain and global evaluation were done With pain relief more than 70% rated as excellent, pain relief between 30%-70% rated as effective and pain relief less than 30% rated as ineffective. Adverse effects were also recorded.RESULTS: Thirty patients were all involved in the final analysis. VAS scores of all three groups were significantly decreased after 15-day treatment (P ＜ 0.05); after 3-day treatment, VAS scores of DR group (2.35±1.43) and SL+DR group (2.41 ±1.54) were significantly lower than their respective baselines and that of the SL group (7.00±0.82) (P ＜ 0.05) which showed no significant change from the baseline value. SL+DR group showed significantly higher excellent rating than that of the SL group and DR group (80%, 60%, 70%, P ＜ 0.05) at the end of the 15-day treatment. At 7th days after treatment, VAS scores of SL group (3.01±1.20) and SL+DR group (2.41±1.54) were still significantly lower than that of DR group (6.70±0.67) (P ＜ 0.05) which had returned to the pretreatment level. No serious adverse effects such as respiratory depression were observed in any of the patients. Mild side effects such as dizziness, nausea and vomiting, constipation were observed in the DR and SL+DR groups which usually subsided after a week.CONCLUSION: Combined therapy of SL and DR shows a better pain relief in the elderly patients with herpes zoster and diabetes without significant adverse effects. It provides the advantage of fast onset of effect with the Durogesic patch and the long-term effect of Super Lizer.

BACKGROUND: During the embryonic stage, E-cadherin expression plays a critical role in the formation of hepatic tissue.OBJECTIVE: E-cadherin gene was transfected into mouse embryonic stem cells (ESCs) to observe its effects on adhesive capacity of differentiated cells.DESIGN, TIME AND SETTING: A cytological in vitro observation was performed at the Laboratory of Surgery, First Hospital Affiliated to Sun Yat-sen University between December 2007 and December 2008.MATERIALS: BALB/c mice at gestational 13 days, of clean grade, were provided by Laboratory Animal Center, Sun Yat-sen University. BALB/c mouse ESCs were preserved by professor Huang Bing from the Department of Ophthalmology, Sun Yat-sen University. CMV promoter-containing eukaryotic expression plasmid pEGFP-N1 was gifted by doctor Lu Zhi-yue from Medical College, Sun Yat-sen University.METHODS: Total RNA was extracted from BALB/c mouse fresh hepatic tissue and synthesized into cDNA by reverse transcription (RT). The synthesized cDNA was used as a template to perform a polymerase chain reaction (PCR) that amplifies a targeted fragment. Following double enzyme digestion, pEGFP-E-cadherin plasmids were reconstructed and transfected into mouse ESCs. In vitro differentiation of transfected mouse ESCs was performed.MAIN OUTCOME MEASURES: Detection of E-cadherin expression in the differentiation system using RT-PCR and immunocytochemistry and observation of adhesive capacity of differentiated cells.RESULTS: E-cadherin gene-transfected ESCs could stably express E-cadherin during differentiational 1-17 days, while non-transfected ESCs expressed a decreasing amount of E-cadherin. The adhesive capacity of differentiated cells that stably expressed E-cadherin was markedly enhanced. Compact cell connection and multi-layer growth state remained at 19 days. While non-transfected ESCs gradually changed from embryoid bodies into noncohesive cell populations.CONCLUSION: Differentiating E-cadherin ESCs exhibit markedly enhanced adhesive capacity and maintain multi-layer growth state.

BACKGROUND:E-cadhedn plays an important role in development of liver tissue in the embryonic stage.Therefore,it is importance for investigating the feasibility of dynamic expression of E-cadherin in embryonic stern cell differentiation to in vitro development of liver tissue.OBJECTIVE:To observe the dynamic expression of E-cadherin in embryonic stem cell differentiation and the effect on cell adhesion.DESIGN,TIME AND SETTING:An in vitro cytological observation was performed at Surgical Laboratory of the First Affiliated Hospital of Sun Yat-sen University from December 2007 to December 2008.MATERIALS:Embryonic stem cells of BALB/c mice were obtained from Professor Huang (Department of Ophthalmology,Sun Yat-sen University).Twenty 13-day-old pregnant BALB/c mice of clean grade were provided by the Experimental Animal Centar of Sun Yat-sen University.METHODS:Following trypsinization,embryonic stem cells were suspend-incubated in DMEM culture medium containing fetal bovine serum,2-mercaptoethanol,HEPES,penicillin,and streptomycin.Embryoid body was formed 5 days after normal development and incubated in the culture plate at day 6.Liver tissue which was obtained from 13-day-old pregnant BALB/c mice was prepared for fetal liver cells which were frozen-sectioned as the controls.MAIN OUTCOME MEASURES:E-cadherin expression was detected using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry st varying time points of 1,5,9,13,and 17 days in stages of initial differentiation of embryonic stem cells,formation of embryoid body,and formation of differentiated clusters.Additionally,the effect of E-cadherin expression on cell adhesion was also detected.RESULTS:RT-PCR showed that E-cadherin mRNA expression was not observed at day 1 but peaked at day 5;gradually,the expression was decreased until the expression was stopped at day 17.E-cadherin mRNA expression was strong in fetal liver cells in the control group.Immunocytochemistry showed a similar outcome.Morphologically,embryonic stem cells developed from unicells into compact three-embryonic layer embryoid body and into incompact cell population.CONCLUSION:E-cadherin expression correlates with differentiated cell adhesion;additionally,the lost expression in an in vitro environment may be an important cause for unable regularization of differentiated cells.

Objective To investigate the effects of structured triglyceride (STG) and physical mixed medium chain/long chain triglycerides (MCT/LCT) on hepatic and renal function and lipometabolism of patients with acute necrotizing pancreatitis (ANP).Methods The clinical data of 30 patients with ANP who were admitted to the PLA General Hospital between January 2012 and June 2014 were prospectively analyzed.A double-blind,randomized,controlled study was performed in 30 patients who were allocated into the experimental group (15 patients received STG) and the control group (15 patients received physical mixed MCT/LCT).All the patients received isometrical nitrogen and isocaloric parenteral nutrition more than 5 days.The levels of alanine transaminase (ALT),aspartate transaminase (AST),glutamyl-transpeptidase (GGT),alkaline phosphatase (ALP),creatinine (Cr),blood urea nitrogen (BUN),triglyceride (TG) and total cholesterol (TC) were assayed before nutritional support treatment and at day 1,3 and 5 after nutritional support therapy.The measurement data with normal distribution was presented as (x) ± s.The skew distribution data were described as M (range).The comparison between groups were evaluated with an independent sample t test or one-way ANOVA.The count data were analyzed using the chi-square test.Results A total of 30 patients were screened for eligibility.The levels of ALT,AST,GGT,ALP,Cr,BUN,TG and TC were changed within a certain range at day 1,3 and 5 after nutritional support treatment.The levels of ALT,AST,GGT,ALP,Cr,BUN and TC before treatment and at day 5after treatment were changed from 29.0 U/L,25.4 U/L,83.2 U/L,(193 ± 115) U/L,(124 ± 97) μmol/L,(8±6)mmol/L and (2.4±1.1)mmol/L to 29.4 U/L,33.0 U/L,77.7 U/L,(172±74)U/L,(117 ±103)μmol/L,(8 ± 5) mmol/L and (2.3 ± 1.0) mmol/L in the experimental group,and from 23.8 U/L,22.9 U/L,96.2 U/L,(148 ± 108) U/L,(82 ± 57) μmol/L,(9 ± 7) mmol/L and (2.5 ± 0.7) mmol/L to 21.3 U/L,24.5 U/L,127.4 U/L,(179 ± 126) U/L,(80 ± 54) μmol/L,(10 ± 6) mmol/L and (2.4 ±0.8) mmol/L in the control group,respectively.There were no significant differences in the changing trends of the levels of ALT,AST,GGT,ALP,Cr,BUN and TC between the 2 groups (F =0.647,1.186,0.282,0.553,0.862,0.182,0.369,P＞0.05).The level of TG in the experimental group from pre-treatment to day 5 after treatment was changed from (1.5 ± 0.6) mmol/L to (1.5 ± 0.7) mmol/L,with increasing trend from pre-treatment to day 1 after treatment and reaching the normal level at day 3 and 5 after treatment.The level of TG in the control group from pre-treatment to day 5 after treatment was changed from (1.5 ± 0.6) mmol/L to (2.4 ± 0.6) mmol/L,with increasing trend from pre-treatment to day 1,3 and 5 after treatments.There were significant differences in the changing trends of TG before and after nutritional support therapy between the 2 groups (F =7.940,P ＜ 0.05).Conclusion STG and physical mixed MCT/LCT don't influence the hepatic and renal function of patients with ANP undergoing parenteral nutritional support therapy,while STG has a better effect of lipometabolism compared with physical mixed MCT/LCT.Registry This study was registered with the UMIN Clinical Trial Registry with the registry number of UMIN000016958

BACKGROUND: Effects of embryonic stem cell-derived hepatocyte-like cell transplantation on oncogenicity of differentiated hepatocyte-like cells and biochemical metabolism of liver should be further studied.OBJECTIVE: To evaluate the therapeutic efficacy of embryonic stem cell-derived hepatocyte-like cell transplantation on the acute liver failure.DESIGN: Randomized controlled study.SETTING: the First Affiliated Hospital of Sun Yat-sen University.MATERIALS: This study was performed at the Central Laboratory, the First Affiliated Hospital of Sun Yat-sen University from January 2005 to February 2006. D3-ES cells extracted from the mice which underwent transfection of green fluorescent protein were graciously presented by professor Huang, Ophthalmology Center of Sun Yat-sen University. Forty 6-week-old D3-129 mice of clean grade and irrespective of gender were provided by Experimental Animal Center of Sun Yat-sen University [certification: SCXK (yue) 2004-0011]. The experimentzl animals were disposed according to ethical criteria.Transforming growth factor, basic fibroblast growth factor, and hepatocyte growth factor were provided by Gibco BRL Company, USA.METHODS: Transforming growth factor, basic fibroblast growth factor, and hepatocyte growth factor were combined to differentiate D3-ES cells into hepatic cells. Cell suspension was poured into liver capsule of 20 mice with 2.0×10(6)cells per mouse. Another 20 mice that determined as the controls were injected with saline. Twenty-four hours later, intraperitoneal injection of 5 μL/20 g carbon tetrachloride was used to induce acute liver failure and to observe quality of life and mean survival time. Twenty-four hours after acute liver failure, vena cava posterior blood was drawn to detect total bilirubin,glutamate-pyruvate transaminase, albumin, blood glucose, pro-time prothrombin time, and other hepatic functional parameters. By scarification, hepatic samples were obtained to evaluate oncogenesis condition, and then HE staining and immunohistochemistry were adopted to detect growth of transplanted cells and albumin expression.MAIN OUTCOME MEASURES: Quality of life, average survival time, hepatic functional parameters, growth of transplanted cells, and oncogenesis condition.RESULTS: Quality of life and average survival time: After the onset of acute liver failure, mice in the control group had incoordination and other symptoms of central nervous system. In addition, 14 mice in the control group and 8 in the transplantation group had abdominal dropsy. Average survival time in the control group was significantly shorter than that in the transplantation group (23, 62 hours, P<0.05). Hepatic functional parameters: Levels of total bilirubin and glutamate-pyruvate transaminase in the control and transplantation groups were higher than those before modeling; levels of albumin and blood glucose were lower than those before modeling; pro-time prothrombin time was significantly longer than that before modeling(P<0.01). Furthermore, levels of total bilirubin and glutamate-pyruvate transaminase in the transplantation group were lower than those in the control group; blood glucose in the transplantation group was higher than that in the control group, and pro-time prothrombin time in the transplantation group was significantly shorter than that in the control group (P<0.05). Growth of transplanted cells and oncogenesis condition: Pathological section demonstrated that structure of liver tissue was not changed remarkably, and tumor was not formed. Moreover, transplanted cells and hepatocyte-like cell were well arranged and combined to express albumin.CONCLUSION: Embryonic stem cell-derived hepatocyte-like cell transplantation can improve quality of life, prolong survival time of model mice with acute liver failure; additionally, transplanted cells may well support biochemical metabolism of liver tissue.

Scanning near-field optical microscopy (SNOM) is developing on the base of near-field optical theory and SPM technique, and producing the highest optical resolution to break through the diffraction limit. It is able to study cellular ultrastructure, function and interaction between biomolecules without destructing the living cells. Recent advances in applying SNOM to cellular and molecular biology were introduced in this review.