BACKGROUND:Constructing a three-dimensional tissue-like structure in vitro plays a critical role in modern tissue engineering and regenerative medicine. Several advances have been made in the past decade. However, it is stil a chal enge to promote microvascular-like structure formation and improve limited nutritional transportation, thereby promoting cel viability.
OBJECTIVE:To explore the feasibility of constructing a three-dimensional microvascular-like structure through the co-culture technique.
METHODS:Human bone marrow mesenchymal stem cel s and human endothelial cel s were co-cultured on a three-dimensional porous silk scaffold. Cel proliferation was analyzed by Pico-green DNA assay. Their growth profiles were evaluated by scanning electron microscope and laser scanning confocal microscopy, respectively. The mRNA levels of von Wil ebrand factor and CD31, two key functional markers of endothelial cel s, in the co-cultured endothelial cel s was assayed by real-time quantitative reverse transcription-PCR.
RESULTS AND CONCLUSION:The three-dimensional culture system constructed by the silk scaffold and bone marrow mesenchymal stem cel s provided an ideal microenvironment for cel growth and proliferation in vitro. Moreover, this microenvironment was capable of promoting endothelial cel differentiation evidenced by their significantly improved mRNA levels of von Wil ebrand factor and CD31. Premicrovascular-like structure was also observed in the co-cultures under the confocal microscope. Thus, al the data supported that the unique co-culture system could promote endothelial cel differentiation and self-assembling in vitro. This culture system provides a robust tool for the studies addressing microvessel-based tissue engineering.

BACKGROUND:The quantity and quality of seed cel s is a critical bottleneck of the development of vascular tissue engineering. To address this issue, stem cel-derived endothelial cel s have been a hot spot in this field due to their potential in providing the ideal seed cel s.
OBJECTIVE:To elucidate the effect of vascular endothelial growth factor (VEGF) supplementation combined with hypoxic culture condition on the lineage-specific differentiation of embryonic stem cel s into endothelial cel s.
METHODS:Serum-free medium mTeSR?1 was applied to cultivate H9 cel s in vitro. A conditioned medium containing 50μg/L vascular endothelial growth factor was utilized to induce H9 cel s to differentiate into endothelial cel s under the hypoxic culture condition (5%O2). The cel under normal condition (5%CO2) with or without vascular endothelial growth factor served as controls. The phenotype and function of human embryonic stem cel s-derived endothelial cel s were assayed by immunofluorescence staining, quantitative RT-PCR, and low-density lipoprotein uptake experiment.
RESULTS AND CONCLUSION:Compared with the control group, the H9 cel s were induced to be differentiated into endothelial-like cel s more efficiently when they were cultivated under a conditioned medium with vascular endothelial growth factor supplementation under the hypoxic condition. These differentiated cel s not only expressed some important surface markers of endothelia cel s, including kdr, pecam, but also took in low-density lipoprotein to form microvessle-like structures. This culture system supports a synergy effect of vascular endothelial growth factor and hypoxic environment that can efficiently promotes the lineage-specific differentiation
of embryonic stem cel s into endothelial cel s with good phenotype and functionality.

Objective To explore the effects of residual renal function (RRF) on quality of life (QOL) in patients with continuous ambulatory peritoneal dialysis (CAPD),and analyze the factors influencing QOL.Methods One hundred and eighteen patients treated with CAPD for at least 3 months in No.455 Hospital of People's Liberation Army were enrolled.All patients were divided into two groups according to residual glomerular filtration rate (rGFR):the group with RRF [rGFR≥ 1 ml·min-1 · (1.73 m2)-1],and the group without RRF [rGFR ＜ 1ml · min-1 · (1.73 m2)-1].The demographic characteristics,laboratory data,cardiothoracic ratio,dialysis adequacy parameters,rGFR,blood pressure,urine volume,ultrafiltration volume and dialysis prescription were investigated.Patient's QOL was evaluated by Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36).Results There was no significant differences between the groups with and without RRF in the age,gender,causes of disease,complication,body mass index (BMI),systolic blood pressure (SBP),diastolic blood pressure (DBP),haemoglobin (Hb),cholesterol,triglyceride,high-density lipoprotein,low-density lipoprotein,normalized protein catabolic rate (nPCR) and cardiothoracic ratio (all P ＞ 0.05).Compared with the patients with RRF,PD duration,ultrafiltration volume,serum creatinine (Scr),calcium,phosphorus,C-reactive protein (CRP),parathyroid hormone (PTH) and peritoneal dialysis dose in the patients without RRF were significantly higher,and urine volume,serum albumin (Alb),potassium,and urea total Kt/V were significantly lower (all P ＜ 0.05).The patients without RRF had a significantly lower score in physical function and physical component summary as compared to the patients with RRF (all P ＜ 0.05).There was no significant differences in role physical,bodily pain,general health,vitality,social function,role emotional,mental health,mental component summary and SF-36 scores (all P ＞ 0.05).Simple linear regression showed that there was no correlation between rGFR and SF-36 scores (β=1.330,P=0.070).Multiple linear regression revealed that SF-36 scores were correlated with CRP (β=-0.477,P ＜ 0.001),Scr (β=0.020,P ＜ 0.001),cardiothoracic ratio (β=-57.823,P=0.004),Alb (β=0.772,P=0.016) and ultrafiltration volume (β=-0.006,P=0.031),but not correlated with rGFR (β=0.099,P=0.302).Conclusions PD patients without and with RRF perceived different scores in physical health,but their scores were similar in mental health and QOL.RRF was no related to QOL in PD patients.Chronic inflammation,fluid overload and malnutrition were the main factors that affect QOL.

Objective To simulate the three-dimensional(3-D) growth pattern of stem cells in vivo by a 3-D culture system in vitro constructed by rat tail collagen scaffold.Methods Circular strands were prepared by mixing suspended murine embryonic stem cells(mESCs) with rat tail collagen.Growth profile of mESCs within the collagen strand was observed with phase contrast microscopy.Their metabolic activity was evaluated by glucose/lactic acid contents.To evaluate the effect of 3D culture system on ESCs differentiation,ES-derived cardiomyocytes were detected by immunohistochemistry,RT-PCR and transmission electron microscopy respectively.Results ESCs grew well in the 3-D culture system constructed by rat tail collagen.Cell connections can be found in those cell clusters formed within collagen stands,which indicated that tissue-like cultures should be produced during the process of 3-D culture in vitro.ESCs cultured by 3-D collagen strand differentiated into cardiomyocytes spontaneously.Conclusion Collagen provides an ideal growth matrix for ESCs proliferation in vitro and promotes ESCs differentiation towards tissue-like structures.Thus,the three dimensional culture system constructed by rat tail collagen can be applied to study ESCs differentiation in vivo.

Objective To research the diagnostic value of troponin in the acute myocardial infarction after cardiac surgery.Methods The prospective study method was used.One hundred and thirtyfour patients of cardiac surgery were selected as observation group,36 patients of thoracic surgery were selected as control group.All the patients were given continuous electrocardiogram monitoring and measured troponin I,and the results were compared between the 2 groups.Results There was no statistical difference in the troponin I before anesthesia between the 2 groups (P ＞ 0.05).The troponin I 4 h after surgery was (13.010 ± 14.829) μg/L in observation group,(0.019 ± 0.007) μg/L in control group,there was statistical difference (P ＜ 0.05).One case of observation group happened the acute myocardial infarction after cardiac surgery,the troponin I was ＞ 40.000 μ g/L.Conclusions The troponin is obviously increased in the early stage in most patients of cardiac surgery,the false positive rate in diagnostic acute myocardial infarction is higher according to the troponin.For troponin,it will need the more evidence of evidence-based medicine to establish the diagnosis of acute myocardial infarction after cardiac surgery.

Objective To evaluate the histocompatibility of novel manufactured xenogenic tendon matrix materials by an animal experimental study.Methods The study was conducted on 15 dogs,weighing 10-13 kg.The prepared xenogenic tendon matrix materials were implanted into the bilateral area of spine in dogs subcutaneously (experimental group),and the implantation of silicon served as control group.The animals were killed 14,30,60 days after surgery and the specimens were processed in laboratory to receive gross and histology observation.The histological sections were stained with hematoxylin-eosin and analyzed by light microscopy.Scores were assigned to the inflammatory process and statistically compared by two related samples with non-parametric test.Results All dogs survived well during the embedded test.There was no tissue necrosis,effusion or inflammation at all implantation sites in both groups during the test.The xenogenic implant materials promoted slight to moderate inflammation process after 14 days,with no statistically significant difference compared to the control.However,after 30 days,there was a regression of inflammation.After 60 days,it was observed the presence of well-organized connective tissue,and few inflammatory cells.Score evaluation of inflammation response at different time after operation of two groups showed no statistically significant difference (P＞0.05).Conclusions The new xenogenic tendon matrix materials are considered biocompatible with subcutaneous tissue.

Objective To determine the power-time-ablation scope correlogram of a water-cooled single needle electrode radiofrequency (RF) ablation system and to establish a theoretical basis for its practical application.Methods RF ablations were performed using a water-cooled single needle electrode radiofrequency ablation system developed by the authors using fresh ox liver as well as liver and muscles of healthy adult New Zealand white rabbits.The temperature of the ablation area was monitored using a multichannel thermometric system.The maximum ablation scope was determined by detecting the rim at which the temperature was no less than 50 °C.The specific absorption rate (SAR) of the isolated liver tissue was calculated.Results In the treatment voltage range of 100-130V,the process was smooth and steady.No impedance variation was obvious.The maximum diameter of a single ablation was 51 cm.With the treatment voltage at 140-170 V,a larger ablation area could be reached in less time,but eventually the impedance began to increase while the ablation area was no longer expanded.When the treatment voltage reached the range of 180-200 V the impedance almost always increased rapidly out of limits,and the treatment system stopped automatically.The measured SAR value was consistent with the theoretical value.Pathology confirmed that both liver tissue and muscle tissue manifested typical coagulative necrosis.Conclusions The power amplifier,cooling,thermometric and control sections of the RF ablation system worked stably,and the practical ablation effect met the design and clinical treatment requirements.

Objective To evaluate the protective effects and mechanism of levocarnitine preconditioning (LCN) on myocardial is-chemia-reperfusion injury in patients undergoing cardiopulmonary bypass .Methods 60 cases of ASA Ⅱ or Ⅲ degree and NYHAⅡ or Ⅲ degree patients who aged 25 ~ 57 years old ,undergoing cardiopulmonary bypass with elective cardiac valve replacement were randomly divided into 2 groups (n = 30 each) :group C (treated with 0 .9% sodium chloride) and group L (treated with LCN) .Group L was infused levocarnitine 50 mg/kg per 1 day at the beginning of 7 days before operation ,group C was given the same amount of 0 .9% sodium chloride .Blood samples were taken from central vein at 5 min after the induction the level of anesthe-sia (T0 ,baseline) ,5 min before aortic cross-clamping (T1) ,30 min after release of the aortic cross-clamp (T2) and at 6 (T3) ,12 (T4) and 24 h (T5) after operation for determination .The level of plasma cardiac troponin I (cTnI) ,creatine kinase-MB (CK-MB) and tumor necrosis factor-α (TNF-α) .Myocardial specimens were obtained from right auricle before aortic cross-clamping and after release of aortic cross-clamp to observe the pathologic changes ,the protein expression of p38 MAPK and phosphorylational-p38 MAPK that analyzed by western blotting .Cardiac index (CI) and left ventricular ejection fraction (LVEF) were measured at 1st day before operation and 7th day after operation by using heart color ultrasonography .Results The levels of cTnI ,CK-MB and TNF-α were significantly lower at all time points in group L than in group C (P< 0 .05) .Myocardial mitochondrion impairment was lighter ,the expression of p38 MAPK and phosphorylational-p38 MAPK were significantly attenuated in group L than in group C (P< 0 .05) .CI and LVEF were significantly higher at 7th day after operation in group L than in group C(P< 0 .05) .Conclusion Le-vocarnitine preconditioning can attenuate myocardial ischemia-reperfusion injury and recover cardiac function in patients undergoing cardiopulmonary bypass ,the mechanism may be related to keep the integrity of the mitochondrial membrane and space structures , inhibit the expression of p38 MAPK and phosphorylational-p38 MAPK and decrease the inflammatory response .

Justified the necessity of remote pathology consultation in China, and described the basic approach of such consultation in terms of the conditions, organizational framework, specialists and consultation process of the hospital. on the basis of benefit in pationts, the consultation helps the development of the pathology department and other specialist departments at the same time, builds initially a pathology quality control system, and accelerates the multi-discipline diagnosis and treatment approach. Expect to encourage contemplation on international remote pathology consultation in an effort to improve such a practice for the benefit of patients.

Objective:To study the association of air pollution with health service demand of the elderly and middle-age patients with cardiovascular and cerebrovascular diseases,and to provide a scientific ba-sis for development of environmental protection policy and health service policy of the Chinese govern-ment.Methods:This study included survey data on self-evaluated health,outpatient service demand and inpatient service demand of the patients with hypertension,heart disease and stroke in 62 cities of 1 7 provinces from China Health and Retirement Longitudinal Study(CHARLS)in 201 1 and 201 3,and com-bined it with the data on the annual concentrations of inhalable particulate matter(PM1 0 ),sulfur dioxide (SO2 )and nitrogen dioxide(NO2 )of those provinces and cities.Conditional Logistic regression was car-ried out to assess the possible effects of air pollutants on self-evaluated health and health service utiliza-tion.Results:The results showed that turning points existed in the effects of concentrations of NO2 and SO2 on the health service demand of the patients with hypertension,heart disease and stroke.The inpa-tient service demand of the hypertension patients increased with NO2 concentration when it was lower than 35.1 μg/m3 and decreased with NO2 concentration for higher value.Self-evaluated health of the patients with heart disease and stroke decreased with SO2 concentration when it was lower than 63.8 μg/m3 and increased with SO2 concentration for higher value.In addition,no evidence was found for the association between PM1 0 and health service demand.Conclusion:Air pollution may have effects on health service demand of the patients with hypertension,cardiovascular and cerebrovascular diseases,and different air pollutants at high or low concentration may have different health effects.