1.Preparation and in vivo biocompatibility evaluation of thermosensitive hydrogel poly-N-isopropylacrylamide-co-N-hydroxymethylacrylamide
Yu HE ; Shuhua YANG ; Tao LI
Chinese Journal of Tissue Engineering Research 2007;0(01):-
AIM: To prepare and evaluate the biocompatibility of a thermosensitive hydrogel poly-(N-isopropylacrylamide-co-N-hydroxymethylacrylamide) (P-NIPAAm-co-NHMPA) in vivo so as to appraise its safety as a medical implant in clinical use. METHODS: The experiments were carried out in the Central Laboratory, Union Hospital, Tongji Medical College, Huazhong University of Science & Technology(HUST) and the Key Laboratory of Biomedical Polymer Materials, Ministry of Education, College of Chemistry, Wuhan University between January and October in 2007. ① Preparation of thermosensitive hydrogel P-NIPAAm-co-NHMPA: Taking ammonium persulfate and tetramethyl ethylene diamine as oxidation-reduction initiation system, while N, N'-methylene bisacrylamide as cross-linking agent, P-NIPAAm-co-NHMPA was prepared with the addition of NHMPA in reaction system. Low critical solution temperature was determined by shrinking tests. ②A series of biocompatibility tests such as sensitization test, acute systemic toxicity test, genetic toxicity test and implantation test were conducted to evaluate the safety of the implant. RESULTS: ①Synthesized hydrogel showed thermosensitive character as expected, and the low critical solution temperature was 38 ℃.②In sensitization test, there was no sensitization proved in the material; in acute systemic toxicity test, the symptom of toxicity was not found; the genetic toxicity test suggested no teratogenic or mutagenic effects; in vivo implantation test showed that the inflammation around the material was mild and limited. CONCLUSION: Thermosensitive hydrogel P-NIPAAm-co-NHMPA has good biocompatibility and is a potential medical implant.
2.Influence of ciliary neurotrophic factor on spinal cord caspase-3 expression in rats of different age following sciatic nerve damage
Chinese Journal of Tissue Engineering Research 2005;9(37):166-169
BACKGROUND: Caspase-3 is a cysteine proteinase that can promote cell apoptosis. Ciliary neurotrophic factor has many kinds of biological activities, such as protecting various neurons from injury, especially motorial neurons, thereby reducing the occurrence of nerve cell injury.OBJECTIVE: To observe the Influence of ciliary neurotrophic factor on spinal cord caspase-3 expression in different ages rats following sciatic nerve injury, aiming to make further investigation about the changing regularity and modulating character of peripheral nerve damage at various ages rats.DESIGN: Randomized controlled experiment.SETTING: Ultrasound Department and the 5th Research Institute of Daping Hospital, Field Surgery Research Institute of the 3rd Military Medical University of Chinese PLA.MATERIALS: This experiment was carried out at the Field Surgery Research Institute of the 3rd Military Medical University of Chinese PLA from April 2000 to December 2001. Altogether 810 wistar rats including infant rats with body mass of 30-100 g (birth age of 20 days), adult rats of 200-350 g (birth age of 4 m), elder rats of 400-800 g (birth age of 18-24 m),were selected with 270 rats in each age stage. Female and male does not limit.METHODS: [1] Experimental animal grouping: Various age rats were randomly divided into normal group (n=18), ciliary neurotrophic factor group(n=126) and physiological saline group (n=126), rats in ciliary neurotrophic factor group and physiological saline group were subdivided into 1 day, 3days, 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks subgroups. [2] Animal model preparation: In Ciliary neurotrophic factor group and physiological saline group, rats were cut off a piece of sciatic nerve of 2 mm long, both ends connected with silica tube for constructing neuranagenesis cab, in which 15 μL recombined ciliary neurotrophic factor (25 mg/L) was injected in ciliary neurotrophic factor group, and 15 μL physiological saline in physiological saline group. [3] Preparation and examination of specimen:Six rats were randomly selected from each group, lumbar L3-5 spinal cord were obtained for carryingonnation, caspase-3 activity examination and Western blotting examination.MAIN OUTCOME MEASURES: [1] Expression of spinal cord caspase-3 with IHC assay. [2] Distribution and expression intensity of spinal cordcaspase-3 by Western blotting technique. [3] Changes in caspase-3 activity.RESULTS: Altogether 810 rats completed the experiment, all data was entered the final result analysis. [1] Expression of spinal cord caspase-3 with IHC assay: After injury, neuronal caspase-3 expression became strengthened at injured side of various age physiological saline groups, which obviously increased at posttraumatic 2 weeks and 4 weeks, but less expressed at 8 weeks and 12 weeks; while in ciliary neurotrophic factor group, posttraumatic caspase-3 expression was mostly obvious at 2 weeks and 4 weeks. [2] Distribution and expression intensity of spinal cordcaspase-3 by Western blotting technique: Caspase-3 expression was not significant difference between various age subgroups in normal group(P > 0.05). Comparing to the same age normal group and non traumatic group, caspase-3 expression was strengthened at 1 week, 2 weeks, 4 weeks in various age physiological saline group and ciliary neurotrophic factor group damages (P < 0.05-0.01); in ciliary neurotrophic factor group, caspase-3 showed weaker expression at 1 week, 2 weeks, 4 weeks in infants; 2weeks and 4 weeks in adults, 4 weeks in elders comparing to corresponding physiological saline group, difference was significant (P < 0.05-0.01).The comparison between untraumatic side of each group and normal group showed no statistical difference (P > 0.05). [3] Changes in caspase-3 activity: In child, adult and elder physiological saline groups, caspase-3 activity was increased in traumatic spinal cord, moreover caspase-3 activity was higher than elder and adult group at various age point (P < 0.05-0.01); in child, adult and elder ciliary neurotrophic factor groups, caspase-3 activity is lower than physiological saline group (P < 0.05-0.01). After damage,caspase-3 activity at traumatic side in physiological saline group and ciliary neurotrophic factor group was difference from normal group but without significant meaning (P > 0.05), except the expression in child posttraumatic 12 weeks group was lower than normal group (P < 0.05).CONCLUSION: After sciatic nerve damage, caspase-3 protein expression and activity were found to be increased in spinal cord of different age groups rats which can be reduced by extragenous ciliary neurotrophic factor, which playing protective role on spinal cord nerve cells, such protection would gradually attenuated in child group, adult group to elder group in turns.
3.Preparation and in vivo biocompatibility of a novel thermosensitive hydrogel
Yu HE ; Shuhua YANG ; Tao LI
Chinese Journal of Tissue Engineering Research 2008;12(6):1157-1160
BACKGROUND: Thermosensitive hydrogel materials present stability at human body temperature, which is necessary for its application as a medical implant, thus the lower critical solution temperature (LCST) of thermosensitive hydrogel should be beyond the human body temperature by adjustment.OBJECTIVE: To prepare a thermosensitive hydrogel poly-N-isopropylacrylamide-co-N-hydroxymethylacrylamide P(NIPAAm-co-NHMPA) with over 37 ℃ LCST, and primarily appraise its safety as a medical implant in vivo.DESIGN: Random, non-blind, group control, animal experimental study.SETTING: Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science & Technology(HUST).MATERIALS: The experiments were carried out in the Central Laboratory, Union Hospital, Tongji Medical College, HUST and the Key Laboratory of Biomedical Polymer Materials of the Ministry of Education, College of Chemistry, Wuhan University between January and October in 2007. NIPAAm monomer and NHMPA monomer were purchased from Aldrich Company, crosslinking agent N, N'-methylene bisacrylamide from Fluka Company, and initiator ammonium persulfate and accelerating agent tetramethyl ethylene diamine from Sigma Company.METHODS: ①Taking ammonium persulfate and tetramethyl ethylene diamine as oxidation-reduction initiation system, while N, N'-methylene bisacrylamide as cross-linking agent, P-NIPAAm-co-NHMPA was prepared with the addition of NHMPA in the reaction system. LCST was determined by shrinking tests.②A series of biocompatibility tests such as sensitization test, acute systemic toxicity test, genetic toxicity test and implantation test were conducted in several experimental animals to evaluate the safety of the implant. MAIN OUTCOME MEASURES: The erythema and edema of stimulated lesions were recorded in sensitization test; the general state of each animal in acute systemic toxicity test were recorded 4, 24, 48 and 72 hours after injection; in genetic toxicity test, mouse bone marrow polychromatic erythrocyte (PEC) micronucleus was counted six hours after injection under microscope; sections after implantation were observed under light microscope.RESULTS: ①Synthesized hydrogel showed thermosensitive character and the LCST was 38 ℃.②In sensitization test, there was no erythema and edema occurred after leaching liquor and saline were injected; acute systemic toxicity test result revealed no symptom of toxicity; the genetic toxicity test suggested no difference of PEC frequency between experimental group and negative control group; in vivo implantation test, the inflammation around the material was mild and limited.CONCLUSION:P(NIPAAm-co-NHMPA) shows good biocompatibility and can be potentially used as an implant material.
4.Analysis on distribution characteristics and risk factors of extended stay at tertiary comprehensive hospitals
Wenhan YU ; Hongbing TAO ; Jinlu HE ; Li JIN ; Pan ZHANG
Chinese Journal of Hospital Administration 2017;33(7):515-518
Objective To analyze the distribution characteristics and risk factors of extended stay over 30 days at tertiary comprehensive hospitals, and explore methods of shortening average length of stay(LOS).Methods Homepage of all inpatients discharged from October 2014 to October 2015 of 31 tertiary comprehensive hospitals in Shanxi province were collected.39 234 cases of these inpatients stayed over 30 days and their case information was complete.A generalized linear model was used for risk factors analysis.Results With the extension of LOS, most of the inpatients with extended stay were found during their 30th-40th days, accounting for 50.21% of all and constituting the highest daily costs as well.The ratio of inpatients decreases with their LOS, and its distribution presents a positive skew in entirety.Distribution of inpatients over 30 days identified urban employees under medical insurance accounting for the highest ratio among all payment categories,and those from the department of orthopedics for the highest ratio among all departments, while those of diseases from injury and poisoning accounting for the highest ratio among all disease categories.The findings indicated ten important factors for extended stay, namely gender, medical payment category, ICD, inter-department transfer, nosocomial infection, and clinical pathway.Conclusions To strengthen management of specific departments and inpatients, focus on key process of medical quality, and accelerate medical insurance payment reform can effectively control extended stay.
5.Surgical treatment and prognosis of incidental gallbladder carcinoma:a study of 27 cases
Qiao WU ; Xiaodong HE ; Wei LIU ; Lianyuan TAO ; Lan YU
Chinese Journal of General Surgery 2010;25(9):725-728
Objective To summarize the clinical and pathological characteristics of incidental gallbladder carcinoma,analyze the factors such as surgical procedures,tumor stages that associated with prognosis,and standardize the diagnosis and treatment strategy of incidental gallbladder carcinoma. Methods Between January 1991 and October 2009,27 incidental gallbladder carcinoma patients were treated in Peking Union Medical College Hospital (PUMCH).A retrospective study was performed based on the clinical data of these patients to evaluate the methods of diagnosis,curative treatment and prognosis. Results Twenty-seven patients were collected (8 male and 19 female) with the mean age of (68.3 ± 1.9)years.Abdominal pain,obstructive jaundice and fever were the main symptoms of incidental gallbladder carcinoma.All the 27 cases underwent open cholecystectomy based on preoperative tentative diagnosis of benign disease,and carcinoma of gallbladder was confirmed by postoperative pathology.In this group(9 lowdifferentiation,9 moderate-differentiation,4 high-differentiation and 5-carcinogenesis from adenoma).Two cases were on the stage of Nevin Ⅰ,5 on Nevin Ⅱ,8 on Nevin Ⅲ,5 on Nevin Ⅳ and 7 on Nevin Ⅴ.The survival terms were of statistic significance between the radical cholecystectomy groups and simple cholecystectomy groups(x2 =4.450,P=0.035); The prognosis of patients on stages Ⅰ、Ⅱ are better than those who are on stages Ⅲ、Ⅳ、Ⅴ (x2 = 6.825,P = 0.014). Conclusion The clinical manifestations of incidental gallbladder carcinoma are diverse,which usually lead to misdiagnosis.Frozen section examination during operation is key to diagnose incidental gallbladder carcinoma.Surgical operation is the first choice of therapy,offering much better prognosis than those received simple cholecystectomy.
6.Biocompatibility of an implantable thermosensitive hydrogel in vitro
Yu HE ; Shuhua YANG ; Shunan YE ; Tao LI
Chinese Journal of Tissue Engineering Research 2009;13(51):10101-10104
BACKGROUND: Thermosensitive hydrogel has made great progresses in drug carrier and tissue engineering. However, its phase-transition temperature is lower than human body temperature, so it has not been used as implants. OBJECTIVE: To prepare and evaluate the biocompatibility of a thermosensitive hydrogel poly-(N-isopropylacrylamide-co-N-hydroxymethylacrylamide)[P(NIPAAm-co-NHMPA)] In vitro so as to assess its safety as a medical implant.DESIGN, TIME AND SETTING: Material experiment was performed at the Central Laboratory of Union Hospital of Tongji Medical College, Huazhong University of Science & Technology and Key Laboratory of Biomedical Polymers, Ministry of Education, Wuhan University Chemical Department from January to October 2007.MATERIALS: L929 mice fibroblast line was provided by Professor Chen, Stomatology Hospital of Wuhan University. N-isopropylacrylamide and N-hydroxymethylacrylamide were purchased from Aldrich.METHODS: Using ammonium persulfate and tetramethylethylenediamine as oxidateion-reduction initiation system and N, N'-methylene bisacrylamide as crosslinking agent, mass fraction 8.5% N-hydroxymethylacrylamide was added to the reaction system. The N-isopropylacrylamide and N-hydroxymethylacrylamide were dissolved in deionized water and reacted with N, N'-methylene bisacrylamide, ammonium persulfate and tetramethylethylenediamine at room temperature for 3 hours. The colorless transparent cylinder gel was obtained, soaked in deionized water and dried.MAIN OUTCOME MEASURES: Biocompatibility in vitro of the material was validated by cytotoxicity test, cells/scaffolds interaction test, hemolysis test and pyrogen test in vitro.RESULTS: Synthesized hydrogel showed thermosensitive character as expected and the lower critical solution temperature was 38 ℃. The toxicity rate was grade 0-1. Through the scanning electron microscopy, cells and scaffolds were tightly attached, producing a perfect interface, and the shape of cells was all right. Hemolysis rate was 2.54%. No pyrogen reaction was found. CONCLUSION: P(NIPAAm-co-NHMPA) has been successfully prepared with good biocompatibility in vitro and might become a good medical implant for clinical use.
7.Effects of dust particles on autophagy of macrophages
Haijie WANG ; Yuzhen TAN ; Tao HE ; Zhang YU
Chinese Journal of Pathophysiology 2000;0(08):-
AIM:To investigate the changes of autophagy of macrophages after phagocytizing dust particles and explore the mechanisms of dust particle-induced autophagy of the cells.METHODS:The bronchopulmonary lymph nodes were collected from patients with lung operation.The paraffin sections were prepared and then stained with Wilder's method.The tissue structures were viewed.Peritoneal macrophages were harvested from rats and then treated with carbon particles.Influences of carbon particles in autophagic activities of macrophages were examined.The ultrathin sections of the lymph nodes and the cells phagocytized carbon particles were prepared.The structures and distribution of phagosomes,autophagosomes and lysosomes were viewed.The apoptotic cells in the dust cells of the lymph nodes and the cells having phagocytized carbon particles were examined using transmission electron microscope and TUNEL staining.RESULTS:In adult lymph nodes,dust particles were deposited significantly in macrophages,collagen fibres and density of microvessels increased.There were autophagosome precursors,autophagosomes,autophagolysosomes as well as phagosomes in the dust cells and the cells phagocytized carbon particles.In autophagosomes,mitochondrion,dust particle or carbon particle were usually observed.There were positive cells by TUNEL staining in the dust cells and the cells phagocytized carbon particles.Nuclear condensation or apoptotic body in the apoptotic cells were observed under transmission electron microscope.CONCLUSION:Deposition of dust particles induces enhancement of autophagic activities and apoptosis of macrophages.Autophagy plays an important role in cleaning dust particles and the injured mitochondria.
8.The Correlation Analysis between Short Term Variation and Basal Heart Rate and Short Time Monitoring Analysis
Zheng WANG ; Tao JI ; Qiang YU ; Zhiwei WANG ; Qicai HE
Chinese Journal of Medical Physics 2009;26(6):1549-1553
Objective: Fetal monitoring is extremely important in perinatal care. Analysis of cardiotocogragh(CTG) can suppose if the fetus is lack of oxygen, distressed, acidosis, etc. in order to take measures timely. Methods: We have designed Meticare analysis software package to analyze 867 pieces of CTG data, and researched the relationship between short term variation (STV) and basal heart rate(BHR) by statistics, and short time monitoring analysis based on STV. Results: The amplitude of fetal heart rate curve variation(long term variation) tended to decrease when BHR increasing, with the negative correlation and regression equation STV = 9.866-0.02×BHR. Positive correlation exists between 5 and 10 mimute-STV, with the regression equation STV_(10min)=2.861-0.596×STV_(5min).Conclusion: STV calculated by 5 minutes CTG data can forecast the one by 10 minutes data as a reference demanded by Dawes & Redman criterion. If fetal doppler contains STV analysis function, out-patient fetal heart auscultation will be more significant. After 30 weeks pregnancy, with the STV decreasing, fetal distress, asphyxia, low birth weight, and even mortality increasing. BHR increasing should cause attention that STV might decrease, when monitoring with no analysis functional devices or fetal dopplars.
9.Effects of brain-derived neurotrophic factor on extracellular proteolytic enzymes
Chunyan SUN ; Yu HU ; Yadan WANG ; Tao WU ; Wenjuan HE
Chinese Journal of Pathophysiology 1986;0(01):-
AIM:To investigate the effects of brain-derived neurotrophic factor(BDNF)on extracellular proteolytic enzymes including matrix metalloproteinases(MMPs)and serine proteases,in particular,the urokinase-type plasminogen activator(uPA)-plasmin system in a human umbilical vein endothelial cell(HUVEC)model.METHODS:The HUVEC was activated with different doses of BDNF(25-200 ?g/L)for different time period(6-48 h).Reverse transcriptase-polymerase chain reaction(RT-PCR)was used to assay MMP-2,MMP-9,TIMP-1,and TIMP-2 mRNA in HUVEC.The cultured conditioned medium was analyzed for MMP and uPA activity by gelatin zymography and fibrin zymography,respectively.uPA,PAI-1,TIMP-1,and TIMP-2 were quantified by Western blotting analysis.RESULTS:The stimulation of serum-starved HUVECs with BDNF caused marked increase in MMP-2 and MMP-9 mRNA expression and induced the pro-MMP-2 and pro-MMP-9 activation without significant differences in proliferation.However,BDNF had no effect on TIMP-1 and TIMP-2 production.BDNF increased uPA and PAI-1 production in a dose dependent manner up to 100 ?g/L,while effects of 200 ?g/L were approximately equal to those of 100 ?g/L.BDNF stimulated uPA and PAI-1 production beyond that in control cultures from 12 h until 48 h after BDNF addition.Protease activity for uPA was also increased by BDNF in a dose dependent manner.CONCLUSION:BDNF activates MMP and uPA/PAI-1 proteolytic network in HUVEC.
10.The risk factors for type 2 diabetes complicated with gallstones
Lan YU ; Xiaodong HE ; Qiao WU ; Wei LIU ; Tao HONG
Chinese Journal of Hepatobiliary Surgery 2011;17(9):790-792
Insulin resistance, lipid metabolism disorders, independent autonomic neuropathy are high risk factors for gallstone formation in type 2 diabetic patients. In recent years, there have been a lot of new developments on the relationship between type 2 diabetes and gallstones, such as adiponectin, leptin and metabolic syndrome, etc. Based on these studies, the risk factors of type 2 diabetes complicated with gallstones are summarized in this paper.