2.Synergistic Effect of Nerve Growth Factor on Ectopic Bone Formation Induced by Recombinant Human Bone Morphogenetic Protein-2
sheng-li, XIA ; ke-rong, DAI ; ting-ting, TANG
Journal of Shanghai Jiaotong University(Medical Science) 2006;0(03):-
Objective To investigate the effect of nerve growth factor (NGF) on the bone induction of recombinant human bone morphogenetic protein-2 (rhBMP-2) through local application of NGF in the osteoinductive process of BMP. Methods Thirty-six ICR mice were divided into the experimental group and control group at random, and rhBMP-2/collagen composite was implanted into the right thigh muscle pouch of each group. NGF or vehicle was daily injected into the implanted sites of BMP, respectively, for 7 days starting from the third day after surgery. At d10, d20 and d30 after implantation, new bone formation was measured radiographically, biochemically and histologically to compare the osteogenetic capacity of the two groups. Results In both groups, new bone formation was found at d10. However, there was significantly more new bone in the experimental group according to histological and radiographic examinations. At d10 and d20, alkaline phosphatase activity of the local tissue in the experimental group was significantly greater than that in the control group, and calcium and phosphonium contents of samples were also greater in the experimental group. Arrangement of collagen fibers became more regular in the experimental group than that in the control group. Conclusion NGF possesses synergistic effect on ectopic bone formation induced by rhBMP-2.
3.The effect of long-term culture in vitro on biological characteristics of human adipose tissue derived stem cells
Hui-Wu LI ; Ke-Rong DAI ; Ting-Ting TANG ; Shengli XIA ; Yaokai GAN ; Yuanqing MAO ;
Chinese Journal of Orthopaedic Trauma 2004;0(10):-
Objective To observe the effect of lnng-term in vitro culture on the biological properties of adipose-derived stem cells(ADSCs)as seeding cells of tissue engineering.Methods The surface makers and apoptosis of primary and passaged human ADSCs were identified by flow cytometric analysis.Osteogenic differentiation of ADSCs at different passages were identified by alkaline phosphatase(ALP),Von Kossa staining and RT-PCR respectively.Results The surface marker expression of mesenchymal stem cells on ADSCs was high and did not change with passages of the cells.The early apoptosis rate of the cells was 1% to 2%,and increased insignificantly from passage one to passage nine.The osteogenic potential of ADSCs confirmed by ALP,Von Kossa staining and RT-PCR was maintained to as late as passage eight.Conclusion Since the biological properties of ADSCs are stable,they can be served as optimal seeding cells for tissue engineering and regenerative research.
4.Clinical feature and management of uveal effusion syndrome
Chan, WU ; Fang-tian, DONG ; You-xin, CHEN ; Rong-ping, DAI ; Ke, TAN
Chinese Journal of Experimental Ophthalmology 2012;30(9):811-814
Background Uveal effusion syndrome is uncommon in clinic.To understand the clinical characteristics of uveal effusion syndrome is helpful for rescuing visual acuity of patient.Objective This study was to discuss the diagnosis,classification and surgical outcome of uveal effusion syndrome.Methods This was a descriptive study.The clinical data of 14 eys from 10 patients with uveal effusion syndrome,ineluding ophthalmologic examination,B-scan sonography,ultrasound biomicroscopy (UBM),fundus fluorescence angiography (FFA),indocyanine green angiography (ICGA),surgical treatment and prognosis,were retrospectively analyzed.The follow-up period was 6 months.Results The fundus findings of all impacted eyes showed bullous-shape retinal detachment (RD).B-scan sonography revealed retinal and choroidal detachment.A annular peripheral ciliochoroidal detachment was observed in the cases under the UBM.FFA exhibited leopard spots without any leakage from choroid into the subretinal space.ICGA demonstrated diffusely choroidal granular hyperfluorescence in the very early phase,which presented with an increasing intensity as time lapse until the late phase.Full-thickness sclerectomy was performed on 4 eyes of 2 patients and subscleral sclerectomy was performed in 1 eye of 1 patient,achieving a retinal anatomic reattachment after surgery.All of the patients finished the fellow-up.No recurrence of RD was seen during the followup duration.Conclusions Comprehensive preoperative evaluation,including ophthalmologic ultrasonography,MRI and CT,is crucial for accurate classification of uveal effusion syndrome and determine of proper management strategy.
5.Epidemiological characteristics of influenza in Mianyang, Sichuan, 2019-2021
WEN Yan ; CHEN Hua ; LIU Shi-an ; YANG Xiao-rong ; CHEN Guo ; DAI Yu-ke
China Tropical Medicine 2023;23(1):64-
Objective To understand the epidemiological and etiological characteristics of influenza in Mianyang City
from 2019 to 2021, so as to provide a basis for the prevention and control of influenza. Methods Influenza surveillance data
in Mianyang City from 2019 to 2021 were collected and analyzed statistically. Results A total of 55 970 cases of influenza
were reported in Mianyang City from 2019 to 2021, with an average annual incidence of 388.08/100 000. A total of 103 723
cases of influenza -like illness cases (ILI) were reported, with an average annual ILI% of 3.58%. The incidence, ILI% , and
positive detection rates of influenza were all far higher than those in the corresponding period in 2019. The classification of the
population is mainly composed of students under the age of 15. The top three reported cases were Fucheng District (20 118,
35.94%), Youxian District (6 394, 11.42%) and Jiangyou District (5 800, 10.36%). 10 126 samples of ILI were received and
detected, with a positive rate of 19.53%, the positive rate of ILI samples was mainly students under 15 years old. The dominant
strains of influenza viruses showed an alternating trend over the years, and A (H3) was the predominant type in 2019. Except for
2 A (H9) strains detected in 2021, the rest were all BV strains. Due to the impact of COVID-19 in 2020, the positive detection
rate was low throughout the year. 43 outbreaks of ILI were reported, which were mainly occurred in winter, and most of them
were in primary schools. Conclusion From 2019 to 2021, the characteristics of cases, ILI, pathogen surveillance and
outbreak events of influenza in Mianyang City are basically the same, with students under 15 years of age and schools
remaining the key population and sites of concern. the importance of non-pharmaceutical interventions for influenza prevention
and control is further evidenced by the low incidence of influenza during the COVID-19 pandemic.
7.Inhibition of protein kinase A leads to cleavage of platelet GP I balpha and downregulation of GP I b-dependent platelet aggregation.
Chinese Journal of Hematology 2009;30(3):171-174
OBJECTIVETo explore the regulatory role of protein kinase A (PKA) in platelet surface glycoprotein (GP) I balpha expression.
METHODSWashed platelets from healthy volunteers were incubated with PKA inhibitor. The N-terminal fragment of GP I balpha (glycocalicin, GC) in the supernatant of platelet suspensions was detected by Western blot and GP I balpha surface expression by flow cytometry. Calpain activity was determined by cytoskeletal proteins proteolysis and calpain surface expression by flow cytometry. The effect of PKA inhibitor on ristocetin-induced platelet aggregation was measured by platelet aggregometer.
RESULTSAfter PKA was inhibited in washed platelets, GP I balpha was cleaved and released to the supernatant, which significantly decreased the surface expression of GP I balpha (P < 0.05). The event was suppressed by pre-treatment with various calpain inhibitors, indicating that PKA inhibitor-mediated shedding was calpain dependent. The actin-binding protein (ABP) and talin proteolysis demonstrated that calpain was activated by PKA inhibitor and expressed on the platelet membrane. Ristocetin-induced aggregation was inhibited by PKA inhibitor.
CONCLUSIONPKA inhibition results in calpain-dependent GP I balpha shedding, which thus reduces GP I balpha surface expression and GP I balpha-dependent platelet aggregation. These results might provide a view to develop new drugs for thrombotic diseases.
Blood Platelets ; drug effects ; Calpain ; metabolism ; Cyclic AMP-Dependent Protein Kinases ; antagonists & inhibitors ; Flow Cytometry ; Humans ; Platelet Aggregation ; drug effects ; Platelet Aggregation Inhibitors ; pharmacology ; Platelet Glycoprotein GPIb-IX Complex ; biosynthesis
8.The influence of lipopolysaccharide on adipose metabolism in liver during shock stage of scalded rats.
Dai-feng HAO ; Zhen-rong GUO ; Jia-ke CHAI ; Yan-qiu WU
Chinese Journal of Burns 2005;21(5):333-335
OBJECTIVETo investigate the influence of lipopolysaccharide (LPS) on adipose metabolism in liver during shock stage of scalded rats.
METHODSSixty adult Wistar rats were inflicted with 30% TBSA full thickness scald and were randomly divided into 3 groups: i. e. sham group (control, n = 20), simple scald group [(n = 20) and LPS group (n = 20, with intra-peritoneal injection of 3.0 mg/kg LPS at 2 postscald hour (PSH)]. The contents of LPS, tumor necrosis factor alpha (TNF-alpha), free fatty acids (FFA) in plasma and adenosine triphosphate (ATP), triglyceride (TG), malonaldehyde (MDA) in liver in each group were determined at 24 and 48 PSH. The histological changes in hepatic tissue in each group were also observed.
RESULTSThe plasma contents of FFA in LPS group at 24 and 48 PSH were 2.3 +/- 0.3 mmol/L and 2.5 +/- 0.4 mmol/L, respectively, which were obviously higher than those in control (0.4 +/- 0.3 mmol/L, 0.5 +/- 0.3 mmol/L) and scald (0.9 +/- 0.3, 1.2 +/- 0.5 mmol/L, P <0.01) groups. Meanwhile, there was obvious difference in the contents of TG and ATP in liver between LPS group (TG: 530 +/- 30 mmol/g, ATP: 1.7 +/- 0.5 micromol/g) and scald group (TG: 242 +/- 27 mmol/g, ATP: 6.0 +/- 2.4 micromol/g, P < 0.01). Pathological examination revealed that adipose denaturalization and injury to mitochondria in hepatocytes in scald group were significantly milder than those in LPS group. The morphology of hepatocyte in control group appeared normal.
CONCLUSIONLPS challenge to burn subjects could induce impairment in utilizing fat derived energy, and it would aggravate adipose denaturalization in the liver.
Adenosine Triphosphate ; metabolism ; Adipose Tissue ; metabolism ; Animals ; Burns ; metabolism ; pathology ; Disease Models, Animal ; Fatty Acids ; blood ; Lipopolysaccharides ; toxicity ; Liver ; metabolism ; pathology ; Male ; Rats ; Rats, Wistar ; Shock ; metabolism ; pathology ; Triglycerides ; metabolism
9.Evaluation of damage to trabecular bone of the osteoporotic human acetabulum at small strains using nonlinear micro-finite element analyses.
Hai DING ; Zhen-an ZHU ; Ke-rong DAI
Chinese Medical Journal 2009;122(17):2041-2047
BACKGROUNDWith advance of age, alterations in bone quality, quantity and microarchitecture render osteoporotic trabecular bone become more sensitive to local failure. The aims of the present study were to clarify the extent to which the distribution of tissue-level stresses and strains was affected by structural changes and the extent to which osteoporotic acetabular trabecular bone was damaged at small strains.
METHODSUsing a DAWING 4000A supercomputer, nonlinear micro-finite element (microFE) analyses were performed to calculate the tissue-level strains and stresses for each element in the trabecular bone of one osteoporotic acetabulum at small strains to quantify the tissue-level damage accumulation and mechanical properties.
RESULTSIn contour plots of the tissue, maximum principal logarithmic strains, high tissue-level strains, both compressive and tensile, were observed in the osteoporotic trabecular bone at small apparent strains from 0.2% to 0.5% strain. The compressive apparent stress-strain curve showed typical nonlinear behavior and tangent modulus reduction with increasing strains. The microdamage curve suggested that microdamage began at 0.2% apparent strain in the osteoporotic trabecular bone and increased sharply, although very few microfractures occurred. The quartiles of the maximum principal logarithmic strains, minimum principal logarithmic strains and Von Mises stresses increased nonlinearly. For the inter-quartile range of the Von Mises stresses, a leap occurred at small strains ranging from 0.2% to 0.3% while microdamage commenced.
CONCLUSIONSExtensive microdamage was primarily responsible for the large loss in apparent mechanical properties that occurred in the trabecular bone of the osteoporotic acetabulum at small strains. With increasing apparent strains, continuous nonlinear increments of tissue-level strains and stresses resulted in microdamage that propagated throughout the specimen with very few microfractures.
Acetabulum ; injuries ; Algorithms ; Compressive Strength ; Computer Simulation ; Finite Element Analysis ; Humans ; Stress, Mechanical ; Tensile Strength
10.Effects of sex and lower extremity alignment on orientation of the knee joint line in knee surgery.
Yi-Ming ZENG ; You WANG ; Zhen-An ZHU ; Ke-Rong DAI
Chinese Medical Journal 2012;125(12):2126-2131
BACKGROUNDDetermination of the proper orientation of the knee articular surface is required both for correction of knee malalignment by osteotomy and for correct component alignment in knee arthroplasty. We sought to determine whether the patients' sex and lower extremity alignment (hip-knee-ankle angle) affects proper knee realignment in osteotomy or component alignment in total knee arthroplasty.
METHODSWe examined 199 healthy adult knees with malalignment of < 5° to determine the mechanical medial distal femoral angle, mechanical medial proximal tibial angle, surgical transepicondylar axis angle, and discrepancies between bone-cut orientations of osteotomy or total knee arthroplasty and the joint line of the distal femoral condyles, posterior femoral condyles and proximal tibial plateaus, using a three-dimensional computed tomography model.
RESULTSThe mean mechanical medial distal femoral angle and mean mechanical medial proximal tibial angle were (94.4 ± 1.9)° and (87.6 ± 1.8)° respectively for women and (93.8 ± 2.0)° and (87.1 ± 1.4)° respectively for men. The surgical transepicondylar axis angle was (2.9 ± 1.6)° for women and (3.2 ± 1.7)° for men. Independent of sex, the hip-knee-ankle angle was closely related to the mechanical medial distal femoral angle and mechanical medial proximal tibial angle, but not to the surgical transepicondylar axis angle. A slightly more valgus alignment of the knee and a more valgus angulation of the distal femoral joint line were found in women, whereas a more varus angulation of the proximal tibial joint line was found in men. Sex had the greatest effect on knee joint line orientation when the lower extremity was valgus in alignment.
CONCLUSIONSA more valgus femoral joint line can be expected in women and in persons with valgus lower extremity alignment; a more varus tibial joint line can be found in men and in persons with varus lower extremity alignment.
Adult ; Arthroplasty, Replacement, Knee ; Bone Malalignment ; pathology ; surgery ; Female ; Humans ; Knee Joint ; pathology ; surgery ; Lower Extremity ; pathology ; surgery ; Male ; Middle Aged ; Sex Factors