Research progress on genetic model of mouse with glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

Glaucoma, currently the world's first irreversible blindness, is a complex multifactorial disease with a genetic predisposition, and pathologically elevated intraocular pressure is its risk factor. The pathogenesis of glaucoma is not fully understood, and most existing studies are based on animal models, with mice as the main research object, and the pathological damage process of glaucoma is reconstructed through experimental induction means or transgenic manipulation to further investigate the relevant pathogenesis and pathological changes. The technique of experimentally induced construction of glaucoma mouse models has been studied by many scholars and is gradually becoming mature. And as research in molecular biology and genetics has advanced, more and more studies have focused on the disease genes associated with glaucoma, and transgenic mouse models have become a hot topic in recent years. In contrast to experimental manipulation to control a single factor, gene editing is better able to simulate the complex process of disease pathogenesis. This paper focuses on providing a more complete direction and strategy for model selection in the future research by describing the progress of research on relevant transgenic mouse model of glaucoma.

LOX-1 Regulation in Anti-atherosclerosis of Active Compounds of Herbal Medicine: Current Knowledge and the New Insight / 中国结合医学杂志

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) have recently been identified to be closely related to the occurrence and development of atherosclerosis (AS). A growing body of evidence has suggested Chinese medicine takes unique advantages in preventing and treating AS. In this review, the related research progress of AS and LOX-1 has been summarized. And the anti-AS effects of 10 active components of herbal medicine through LOX-1 regulation have been further reviewed. As a potential biomarker and target for intervention in AS, LOX-1 targeted therapy might provide a promising and novel approach to atherosclerotic prevention and treatment.

Comparisons of Emu Necrotic Femoral Head Micro Structure Repaired in Two Different Methods / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare emu necrotic femoral head micro structure repaired in two different methods.</p><p><b>METHODS</b>Fifteen adult emus were divided into 3 groups (all n=5), and the right femoral head was selected to research. The first group was the control group; in the second group, femoral head necrosis was made by cryogen with liquid nitrogen; and in the third group, femoral head necrosis was made by local pure ethanol injection. Right femurs were taken for micro CT examination,then femoral head micro structures were compared among these three groups.</p><p><b>RESULTS</b>No infection or unexpected death was found in all groups. Compared with normal group, necrotic femoral heads in cryogen group showed that bone mineral density significantly reduced after repaire (P=0.015), trabecular space significantly reduced (P=0.001), bone volume fraction significantly enlarged (P=0.036), bone surface/volume fraction (P=0.032) and trabecular numbers (P=0.002) significantly enlarged; trabecular thickness showed no significant difference (P=0.060). Compared with control group, necrotic femoral heads in ethanol group showed that bone mineral density significantly enlarged after repaire (P=0.001), trabecular thickness (P=0.003) and bone surface/volume fraction (P=0.022) significantly enlarged, trabecular space (P=0.001) and bone volume fraction (P=0.001) significantly reduced; the trabecular numbers showed no significant difference (P=0.143). Compared with ethanol group, necrotic femoral heads in cryogen group showed significant lower bone mineral density after repair (P=0.001), significantly lower bone volume fraction (P=0.001), significantly lower trabecular thickness (P=0.001), significantly higher bone surface/volume fraction (P=0.022) and higher trabecular numbers (P=0.003); the trabecular space showed no significant difference (P=0.398).</p><p><b>CONCLUSION</b>Different repair methods make reconstructed femoral head weight bearing area have different bone structure and bone mineral density, along with different bone trabecular quality.</p>

Study of animal model of osteonecrosis induced by local ethanol injection in emu / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a new animal model of osteonecrosis of the femoral head by local ethanol injection in emu.</p><p><b>METHODS</b>Eight milliliter ethanol was injected slowly to the operated femoral head with customized probe in twenty adult male emus. Postoperatively, hip magnetic resonance imaging was performed at 1, 4, 8, 12 weeks. After emus were sacrificed, the femurs were collected for micro-computed tomography and histological analysis.</p><p><b>RESULTS</b>No emu demonstrated signs of infection or died unexpectedly. Magnetic resonance imaging examination showed broad edema at proximal femur at 1(th) week, and the edema decreased with time, till local edema at femoral head at the 12(th) week. Histological images showed human-like osteonecrotic changes with active bone repair. There were significant differences in trabecular structure and bone mineral density between the operated and intact femoral heads. No collapse was found 6 months after the operation.</p><p><b>CONCLUSIONS</b>This emu model of femoral head osteonecrosis by local ethanol injection can progress to early stage osteonecrosis. The different repair methods may have certain correlation with the results of osteonecrosis of the femoral heads.</p>

Combined effects of NEL-like type 1 gene and zoledronate in preventing collapse of the femoral head / 中国医学科学院学报

<p><b>OBJECTIVE</b>To determine if combined therapy consisting of NEL-like type 1 gene (NELL-1) and zoledronate can prevent the collapse of the femoral head and stimulate the new bone formation in an animal model of osteonecrosis.</p><p><b>METHODS</b>Ischemic osteonecrosis was surgically induced in 24 SD rats, whicih were equally randomly divided into three groups: combination group, treated with both NELL-1 and zoledronate; sham operation group; and placebo group, treated with normal saline solution. The animals were killed 5 weeks after surgery. Radiography, MicroCT, histology, and immunohistochemistry were performed to analyze the results.</p><p><b>RESULTS</b>Morphologically, the femoral head was at good shape in the combination group, while mildly flattened femoral head was seen in the placebo group. No heterotopic ossifications were observed in each group. MicroCT assessment showed significantly higher total and bone mineral volume in the combination group than in the placebo group (P<0.01), whereas no such significant difference was found when compared with the sham operation group(P>0.05). Histological assessment showed more active osteoblast activity and reduced osteoclast activity in the combination group compared with placebo group.</p><p><b>CONCLUSION</b>A combination of NELL-1 and zoledronate can decrease the femoral head deformity while stimulating bone formation in a traumatic rat osteonecrois model, showing a potential to reverse the osteonecrosis.</p>

Effect and mechanism of zoledronate on prevention of collapse in osteonecrosis of the femoral head / 中国医学科学院学报

<p><b>OBJECTIVE</b>To observe the effect and mechanism of zoledronate on prevention of collapse in an animal model of osteonecrosis.</p><p><b>METHODS</b>Ischemic osteonecrosis was surgically induced in 16 SD rats (which were further divided into zoledronate group and placebo group); another 8 rats were used as sham surgery group (n=8). The animals were killed 5 weeks after surgery. Radiographic, Micro-CT, histological, and immunohistochemical assessments were performed.</p><p><b>RESULTS</b>Radiographic assessment showed better preservation of the femoral head shape in the zoledronate group than in the placebo group but not significantly different from the sham surgery group. Micro-CT assessment showed higher total volume, bone volume, and total mineralized content in the zoledronate group(all P0.05). Compared with the placebo group, the zoledronate group had reduced osteoclast and osteoblast activity, as confirmed by histological examinations.</p><p><b>CONCLUSION</b>Zoledronate can decrease the femoral head deformity by reducing the osteoclast activity while suppressing new bone and vessels formation in a rat model of traumatic osteonecrosis, and therefore may delay the collapse of femoral head.</p>

Three-dimensional deformation field measurement system based on micro-CT images / 医用生物力学

Objective To develop a novel measurement system composed of micro-CT, mechanical loading device and digital volume correlation (DVC) technique, so as to measure the three-dimensional microstructural deformation field in bone tissue. Methods Uniaxial compression was applied on the specimen with the micromechanical loading device, and CT scans were also conducted while maintaining the same loads; then sequential CT images were matched and searched accordingly by DVC method to calculate the micro-displacement in the specimen along three directions before and after loading; repeated scanning of zero-displacement and rigid body translation were used to evaluate the accuracy and precision of the system. The three-dimensional distribution of displacement field in bovine cancellous bone was measured by the system. Results The result from repeated scanning of zero-displacement showed that the highest accuracy of measurement was performed in the loading direction and the precision was less than tenth of the CT resolution. The result of rigid body translation showed that the standard deviation was 0.001~0.002 μm. For cancellous bone specimen under the load of 600 N, the range of micro-displacement was 100.35~110.25 μm, with multilayer field distribution. Conclusions The accuracy and precision of this measurement system can meet the requirement of DVC method. It is proved that this system can be used for measuring the three-dimensional micro-deformation field in the cancellous bone and as a measurement platform for investigating the relationship between deformation distribution and structural response in bone tissue for the future research.

Study on differentiation of rat adipose tissue-derived stromal cells into Schwann-like cells / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the phenotypic, molecular and biological characteristics of adipose tissue-derived stromal cells (ADSCs) differentiated alonely a Schwann cells (SCs) lineage and to provide a new cells' seed source for nerve tissue engineering or cell therapy.</p><p><b>METHODS</b>Cultured ADSCs were isolated from SD rats and the undifferentiated ADSCs were confirmed by detection of MSC-specific cell-surface markers. The ADSCs were differentiated along a glial cell lineage using an established cocktail of growth factors. Following differention, we used immunofluorescene staining and RT-PCR to evaluate the characteristics of differentiated WJMSCs.</p><p><b>RESULTS</b>ADSCs were successfully isolated from the rats' fat tissue. The isolated ADSCs expressed CD29, CD90 but not CD34, CD44 nor CD45. Osteogenic differentiation was detected by Alizarin red staining and adipogenic differentiation was comfirmed by Oil-red O staining. ADSCs treated with a mixture of glial growth factors adopted a spindle-like morphology similar to Schwann cells. Immunocytochemical staining and RT-PCR analysis revealed that the treated cells expressed the glial markers S100, P75 and glial fibrillary acidic protein indicative of differentiation.</p><p><b>CONCLUSION</b>ADSCs can be differentiated into cells that are Schwann-like in terms of morphologic features and phenotype and could be suitable Schwann-cell substitutes for nerve repair in clinical applications.</p>

Comparison of the effects of recombinant human endostatin and docetaxel on human umbilical vein endothelial cells in different growth states / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recombinant human endostatin (rh-endostatin, Endostar) has been proved to be an inhibitor of angiogenesis. Docetaxel has been also considered as a common chemotherapeutic agent with inhibition of angiogenesis of malignancies. However, their function has been seldom compared and a best synergism protocol is not determined. This study aimed to compare the effects of two drugs, investigate their combined impact on human umbilical vein endothelial cells (HUVECs), a molecular basis and find ideal protocols to inhibit endothelial cell proliferation.</p><p><b>METHODS</b>HUVECs on confluent growth or activated by vascular endothelial growth factor (VEGF) were treated by rh-endostatin or/and docetaxel at respective gradient concentration in following operations as cell proliferation determined by MTT assay, cell cycle distribution, apoptosis and markers of CD146, CD62E and CD105 detected by flow cytometery, the structure of the channel formed by HUVECs measured by tube formation count.</p><p><b>RESULTS</b>Rh-endostatin exhibited time dependent inhibition of proliferation while docetaxel showed both time and dose dependent inhibition. HUVECs accumulated in G(0)-G(1) with decreased numbers of cells in G(2) after a single treatment of rh-endostatin or that followed by docetaxel treatment. Cells accumulated in G(2) after both a single docetaxel and simultaneous administration. Both the number of cells in G(0)-G(1) and apoptotic cells were increased by docetaxel followed by rh-endostatin treatment. The number of non-apoptotic cells at G(0)-G(1) was increased by first administering rh-endostatin then docetaxel. Sequential treatment of docetaxel followed by rh-endostatin resulted in the greatest increase in apoptosis (34.7%) and the second highest apoptosis was seen with simultaneous administration (18.2%). Expression of CD146 and CD105 on confluent HUVECs was reduced at certain doses of rh-endostatin and/or docetaxel. However, rh-endostatin reduced CD105 without any apparent impact on either CD146 or CD62E expression, whereas these markers were down-regulated by docetaxel after pre-activation by VEGF. Rh-endostatin treatment maintained tube-like structures for a limited time. In contrast, docetaxel swiftly reduced tube formation. Simultaneous treatment, or docetaxel followed by rh-endostatin, exhibited a stronger inhibition on tube formation than either agent alone.</p><p><b>CONCLUSIONS</b>Both rh-endostatin and docetaxel can inhibit HUVEC proliferation while the high apoptotic rate after combined administration was probably owing to different sequent administration by docetaxel followed by rh-endostatin or simultaneous treatment. Both proliferation and adhesion molecules on HUVECs of confluent growth are down-regulated by the two drugs. The rh-endostatin decreased proliferation markers, but only slightly modified adhesion molecules, while both markers were down-regulated by docetaxel on HUVECs activated by VEGF. Rh-endostatin could maintain adhesion of HUVECs at first then induce cells apoptosis to damage tube formation. We hypothesize that it could lead to vascular normalization in short time. In contrast, docetaxel can suppress HUVEC proliferation, adhesion, and reduced tube formation swiftly due to its cytotoxicity. Combined treatments can induce a synergistic inhibition of tube formation.</p>

Biocompatibility evaluation of electrospun aligned poly (propylene carbonate) nanofibrous scaffolds with peripheral nerve tissues and cells in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Peripheral nerve regeneration across large gaps is clinically challenging. Scaffold design plays a pivotal role in nerve tissue engineering. Recently, nanofibrous scaffolds have proven a suitable environment for cell attachment and proliferation due to similarities of their physical properties to natural extracellular matrix. Poly(propylene carbonate) (PPC) nanofibrous scaffolds have been investigated for vascular tissue engineering. However, no reports exist of PPC nanofibrous scaffolds for nerve tissue engineering. This study aimed to evaluate the potential role of aligned and random PPC nanofibrous scaffolds as substrates for peripheral nerve tissue and cells in nerve tissue engineering.</p><p><b>METHODS</b>Aligned and random PPC nanofibrous scaffolds were fabricated by electrospinning and their chemical characterization were carried out using scanning electron microscopy (SEM). Dorsal root ganglia (DRG) from Sprague-Dawley rats were cultured on the nanofibrous substrates for 7 days. Neurite outgrowth and Schwann-cell migration from DRG were observed and quantified using immunocytochemistry and SEM. Schwann cells derived from rat sciatic nerves were cultured in electrospun PPC scaffold-extract fluid for 24, 48, 72 hours and 7 days. The viability of Schwann cells was evaluated by 3-[4,5-dimethyl(thiazol-2-yl)-2,5-diphenyl] tetrazolium bromide (MTT) assay.</p><p><b>RESULTS</b>The diameter of aligned and random fibers ranged between 800 nm and 1200 nm, and the thickness of the films was approximately 10 - 20 µm. Quantification of aligned fiber films revealed approximately 90% alignment of all fibers along the longitudinal axis. However, with random fiber films, the alignment of fibers was random through all angle bins. Rat DRG explants were grown on PPC nanofiber films for up to 1 week. On the aligned fiber films, the majority of neurite outgrowth and Schwann cell migration from the DRG extended unidirectionally, parallel to the aligned fibers. However, on the random fiber films, neurite outgrowth and Schwann cell migration were randomly distributed. A comparison of cumulative neurite lengths from cultured DRGs indicated that neurites grew faster on aligned PPC films ((2537.6 ± 987.3) µm) than randomly-distributed fibers ((493.5 ± 50.6) µm). The average distance of Schwann cell migration on aligned PPC nanofibrous films ((2803.5 ± 943.6) µm) were significantly greater than those on random fibers ((625.3 ± 47.8) µm). The viability of Schwann cells cultured in aligned PPC scaffold extract fluid was not significantly different from that in the plain DMEM/F12 medium at all time points after seeding.</p><p><b>CONCLUSIONS</b>The aligned PPC nanofibrous film, but not the randomly-oriented fibers, significantly enhanced peripheral nerve regeneration in vitro, indicating the substantial role of topographical cues in stimulating endogenous nerve repair mechanisms. Aligned PPC nanofibrous scaffolds may be a promising biomaterial for nerve regeneration.</p>

A new animal model of osteonecrosis induced by focal alternative cooling and heating insults / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a new animal model of osteonecrosis of the femoral head(ONFH) with improved consistency and incidence of femoral head collapse for studies on the mechanism of osteonecrosis. and on the assessment of treatment effectiveness.</p><p><b>METHODS</b>Twenty adult male emus were used. Guide instrumentation was constructed to position the customized probe just articularly and at the proximal part of the femoral head. An alternating focal liquid nitrogen freezing and radiofrequency heating was applied. At 2, 4, 8, 12 and 16 weeks after surgery, hip magnetic resonance imaging (MRI) was performed. Before the emus were sacrificed, barium sulfate was infused to lower extremities for microangiography. The femoral samples were scanned by micro-computed tomography (Micro-CT) and evaluated histologically.</p><p><b>RESULTS</b>No bird demonstrated signs of infection or died unexpectedly. Hip MRI showed changes massive edema at the 4th week, increasingly localized abnormal signals at the 8th'" week, and femoral head collapse at the 12'h week. Micro-CT scans and histological images at the 16th week showed human-like osteonecrotic changes with impaired local blood supply. Bone mineral density of the collapsed head was (380. 31 + 28. 12) mg/cm3 and trabecular spaces were (0. 86 ±0.32) mm; both were significantly lower than those in the control side, which were (415.75 41.28) mg/cm3 and (1. 17 ± 0. 17) mm, respectively (P < 0. 05). Bone volume fraction of the collapsed head was(47.28 ± 17. 14)% and trabecular thickness was (506. 17 ± 220. 58) p.m; both were significantly higher than those at control side, which were (30. 92 ± 4. 01)% and (325. 50 ±44. 53) pm, respectively (P <0. 05). The microangiography at the 16th week showed that vessel volume fraction was (0. 315 ± 0. 055)% , which was significantly higher than the collapsed side [ (0. 142 ± 0. 059)% ] (P <0. 05).</p><p><b>CONCLUSIONS</b>The emu model of fem-oral head osteonecrosis was successfully established using focal alternating cooling and heating insults. The models, with improved consistency and incidence of femoral head collapse, can be used in studies on the mechanism of osteonecrosis and on the assessment of treatment effectiveness.</p>

Influence of ATP-binding cassette transporter A1 protein in eukaryocyte and its expression on arsenic resistance / 中国地方病学杂志

Objective To examine the expression of ATP-binding cassette transporter A1(ABCA1)in eukaryotie cells and the effect of arsenic resistance after the transfection of eukaryotic expression vector containing ABCA1 gene.Methods HeLa cells were transfected with the recombinant plasmid by lipofectaonmine 2000 (recombinant plasmid group),empty plasmid and untransfected HeLa cell as the control group.The level of the mRNA was examined by real-time PCR,and the expression of ABCA1 protein wag examined by Western blot,the change of cell survival rate was examined by methyl thiazolyl tetrazolium(MTT)after exposure in a series of arsenic [0(contro1),4,8,16,32,64,128 μmol/L]for 48 hours.Results Expression level of ABCA1 mRNA in recombinant plasmid,empty plasmid and untransfeeted groups was(2.09±0.08)×10-4,(0.09±0.02)×10-4,(0.08±0.02)×10-4,there was a significant difference between the groups(F=1499.23,P<0.01).The level of ABCA1 mRNA in recombinant plasmid group was higher than empty plasmid and untransfected group(all P<0.01).Western blot showed that specific protein straps existed at 254×103 in all the three groups,with a similar size to the ABCA1 protein.The amount of the recombinant plasmid group was higher than the other two groups.MTT shows that arsenic concentration at 4,8,16,32,64,128 μmol/L,the survival rates of recombinant plasmid group was(94.8±0.9)%,(86.5 ± 2.6)%, (77.8 ± 2.0)%, (56.0 ± 2.0)%, (23.8 ± 1.7)%, (18.6 ± 0.6)%, higher than that of empty plasmid group[ (85.3 ± 1.1)%, (78.7 ± 0.6)%, (67.8 ± 2.4)%, (43.2 ± 1.5)%, (14.5 ± 1.3)%, (8.0 ± 0.4)%], the difference of survival rate had a statistical signifieance(t = 18.985,6.689,5.922,9.504,9.481,32.634, all P < 0.01). Conclusions ABCA1 protein is over expressed in HeLa cells after transfect ABCA1 gene. ABCA1 protein increases resistance of arsenic in HeLa cells.

Mechanisms of autologous chondrocytes mass transplantation in the repair of cartilage defects of rabbits' knee / 中国骨伤

<p><b>OBJECTIVE</b>To trace the pathological changes of the cultured autologous chondrocytes mass after implanted in cartilage defects and investigate the pathophysiological mechanisms of the antologous chondrocytes mass transplantation in the repair of cartilage defects.</p><p><b>METHODS</b>Twenty-four New Zealand white rabbits of 4 to 6 month-old and weighing more than 3.0 kg (female and male was unrestricted) were randomly divided into experiment group and the control group. For 12 rabbits of experiment group, the cartilage defects were repaired with the autologous chondrocytes mass and sealed with one piece of periosteum. Firstly, cartilage tissue of 10 to 30 mg was obtained from the shoulder of the rabbits after anaesthetized by 1 mg/kg 20% sumianxin. Then, chondrocytes were isolated from the cartilage tissue with 0.2% type II collagenase digestion and were cultured in DMEM/F-12 supplemented with 20% fetal bovine serum (FBS), 50 microg/ml ascorbic acid-2-phosphate, 0.4 mM proline, 5 microg/ml insulin and 1 mM non-essential amino acids (NEAA) in flasks in vitro. The cells were harvested until a thin film of the cells covered the bottom of the flask could be seen with naked eyes. Then the film was collected with a curled glass stick and formed a solid mass. On this time, the animal was anaesthetized again and the full-thickness cartilage square defect of 4.0 mm x 6.0 mm was fabricated in the patellar grove of distal femur, and then the cellular mass was transplanted into the defect covered by one piece of periosteum which obtained from the upper anterior of tibia and sealed with the femoral condyles. For 12 rabbits of the control group, the defects were sealed with one piece of periosteum only. The animals were sacrificed in the 1st, 3rd, 6th and 12th weeks after the operation respectively. The histologic sections were stained with safranin O-fast green, hematoxylin-eosin (H&E) and picric acid-Sirius red and immunostained for type II collagen and aggrecan.</p><p><b>RESULTS</b>In the 1st week, the transplanted cells oriented to articular surface differentiated to matured hyaline chondrocytes and excrete large amount cartilage matrix. In the 3rd week, the trend was more obvious and the periosteum was union to the cell mass. In the 12th week, the defects were repaired with hyaline-like cartilage tissue, and in the 24th week, the repair tissue turned to matured hyaline cartilage. In the control group, the defects were repaired with fibrocartilage tissues.</p><p><b>CONCLUSION</b>It was evidenced that the defects were repaired by the autologous chondrocytes mass transplantation. The procedure was gradual and initialed from up toward joint to down to the deep of the defect.</p>

Fabrication and characteristics of oriental poly (lactic-co-glycolic acid) scaffold: a preliminary study / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the method of fabricating oriental scaffolds and investigate the biocompatibility of the scaffolds as well as cells distribution within the scaffolds in vitro.</p><p><b>METHODS</b>The oriental poly (lactic-co-glycolic acid) (PLGA) scaffolds were fabricated with modified emulsion-phase separation method. The scaffolds were treated with plasma and then anchored with collagen I. Articular chondrocytes were loaded into the scaffolds. The growth status and distributing characteristic of the cells were investigated by environmental scanning electron microscope.</p><p><b>RESULTS</b>The scaffold was well compatible with the articular chondrocytes. The cells could reach to 2.5 mm depth with unilateral loading. The cells distributed evenly in the scaffold and lined along the inner pipes.</p><p><b>CONCLUSIONS</b>The oriental scaffold fabricated could significantly promote the distributing characteristics of the chondrocytes. The vertical alignment of the chondrocytes within the scaffold is closely similar to that of articular cartilage.</p>

Analysis of cavitation of advanced NSCLC treated by rh-endostatin combined with NP chemotherapy / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the significance of intra-tumoral cavitation in the patients with advanced NSCLC treated by rh-endostatin plus NP chemotherapy.</p><p><b>METHODS</b>Fifty-seven patients with advanced NSCLC were randomly assigned to receive chemotherapy with rh-endostatin plus NP or NP alone. The numbers of activated circulating endothelial cells (aCECs) were measured by flow cytometry. Chest computed tomography was performed to evaluate the efficacy after 2 cycles of chemotherapy.</p><p><b>RESULTS</b>Cavitation occurred in 5 of 29 patients in the rh-endostatin plus NP group, but not in any case of the NP group. Of the 5 patients, there were 2 males and 3 females, with pathological types of 3 adenocarcinomas, 1 adenosquamous cell carcinoma and 1 sarcomatoid carcinoma. All of these 5 cases had a peripherally located tumor in the CT scan. There was only one cavity in each case and most of these were roundish. Four cavities were situated in the center of the tumor and another one was eccentric. There were 3 cavities with thin wall and 2 with thick wall. Their average diameter was 2.7 cm. No hemoptysis occurred in these 5 patients. The blood-supply of the tumors showed by perfusion CT images was inhibited in 3 cases after treatment. The average number of aCECs decreased from 323.2/10(5) to 33.0/10(5) after treatment.</p><p><b>CONCLUSION</b>Intratumoral cavitation is a peculiar imaging characteristics after anti-angiogenic therapy, which may be caused by inhibition of blood-supply to the tumor. CT perfusion imaging and measurement of activated circulating endothelial cells may be helpful to predict the efficacy of anti-angiogenic therapy combined with chemotherapy.</p>

Biological characterization of rabbit's articular chondrocytes by confluent culture in vitro / 中华外科杂志

<p><b>OBJECTIVE</b>To obtain large amount of differentiated chondrocytes in vitro, examine and compare the biological characterization of rabbits' articular chondrocyte cultured in different density in vitvo.</p><p><b>METHODS</b>From November 2001 to June 2004, articulate tissues were obtained from the joints of the adult rabbits. Chondrocytes were isolated from the cartilage tissue with type II collagenase digestion and cultured in DMEM/F-12 supplemented with 20% fetal bovine serum (FBS). The chondrocytes were cultured with low density of monolayer culture and high density of confluent culture respectively. The differentiated phenotype was evaluated by histochemistry or immunohistochemistry.</p><p><b>RESULTS</b>When chondrocytes cultured in monolayer and in low density, it proliferated rapidly during the three generations, but with the same time, dedifferentiation was also rapid. After the third passage, most of the passage cells lost the phenotype, and the proliferation also stagnated. While chondrocytes cultured in high density, dedifferentiation slowed down. And even the phenotypes of the dedifferentiated chondrocyte which were cultured in low density could reduced partly by followed high density culture.</p><p><b>CONCLUSIONS</b>Culture chondrocytes by high density in vitro can effectively maintain the differentiated phenotype of chondrocyte. It also keeps the proliferation character as monolayer culture. The dedifferentiated chondrocyte caused by many passages could redifferentiate partly. So it is indicated that confluent culture of original or expanded chondrocytes in high density is a better culture methods than culture in low density.</p>

Influences of decellularization processes on immunogenicity of chemically acellular nerve allografts / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the relationship between immunogenicity and decellularization processes of chemically acellular nerve allografts.</p><p><b>METHODS</b>Adult Sprague Dawley rats were used as nerve donors and adult male Wistar rats used as nerve recipient hosts. 25 mm nerve segments were excised from SD rats' sciatic nerves. The nerve segments were decellularized via an improved chemical decelluarization treatment as follows: (1) nerve segments were rinsed with cold sterile Ringer's solution; (2) stabilized by pinning the ends to a thin plastic support, and submerged in 4% Triton-100 solution 12 h; (3) soaked into 3% sodium deoxycholate for 12 h; (4) washed in distilled water for 6 h. The procedures were repeated once again. The acellular nerve allografts from SD rats were sterilized by gamma irradiation and implanted into Wistar rats subcutanously. The control group was implantation of fresh nerve allografts from SD rats. The immunogenicity of acellular nerve allograft was tested by immunohistochemical examination of the intensity of CD3(+), CD4(+) and CD8(+) cells that infiltrated the allografts. Ulnar nerve segments were obtained from forearms of dogs and decellularized according to above procedures. According as the decellularization times, The ulnar nerve segments were divided into three subgroups: in group I, group II and group III, the nerve segments were decellularized repeatedly two, three and four cycles respectively. Each ulnar nerve segment was subdivided into five portions from proximal to distal end. The degrees of decellularization, demyelination and basal lamina integrity of extracellular matrix scaffold were observed with microscope and assessed by a score system. The immunohistochemical staining of GAG was observed.</p><p><b>RESULTS</b>The intensity of CD3(+), CD4(+) and CD8(+) T cells that infiltrated the allografts was greatly lower in acellular nerves than in fresh nerves. The mild cell-mediated host-graft immunorejection in acellular nerves was observed. On the decellularization procedures, the cells were completely extracted from nerves in all groups, but the myelin sheath were partially existed, and the GAG was present in the basal membrane of myelin sheath. In the score of demyelination, there were no statistical differences between groups (P > 0.05). The statistical difference of basal lamina integrity scores between group I and group II, group I and group III were significant (P < 0.05). As increasing the times of process, the degrees of disintegrity of basal lamina was significantly enhanced.</p><p><b>CONCLUSIONS</b>Although decellularization processes significantly reduce the cell-mediated immunorejection of acellular nerve allografts, it can induce mild immunoreaction all the same, the antigen that responsible for immunogenicity may be the residual component of GAG in myelin sheath.</p>

The preparation, structure evaluation and preliminary application of biomimetic biphasic calcium phosphate scaffold / 中华外科杂志

<p><b>OBJECTIVE</b>To fabricate biomimetic biphasic calcium phosphate BCP ceramic scaffolds using three-dimensional (3D) gel-lamination technology and evaluated their structure with 3D parameters and related method.</p><p><b>METHODS</b>Series two-dimensional images of femoral head's specimen of dogs were obtained by micro-computed tomography (Micro-CT). According to these images, porous biomimetic biphasic calcium phosphate (BCP) ceramic scaffolds with oriented trabecular structure were fabricated by three-dimensional (3D) gel-lamination technology. And then, the three-dimensional structure of the scaffolds were reconstructed by computer according to Micro-CT images of these scaffolds and evaluated by three-dimensional parameters. These parameters included bone volume fraction (BVF, BV/TV), bone surface/bone volume (BS/BV) ratio, trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular spacing (Tb.Sp) and structure model index (SMI). The biomechanical properties and biocompatibility of these scaffolds were also evaluated in the study. Six scaffolds, which were combined with BMCs (bone mesenchymal cells, BMCs), were planted into the bone defect of six dogs' femoral head respectively.</p><p><b>RESULTS</b>There was no significant difference between trabecular samples and BCP scaffolds in BV/TV, Tb.Th, Tb.N, and Tb.Pf (P > 0.05). The trabecular system of the scaffold, which had some orientation, represented plate-like model. With a micro-porous porosity of 62%, the average compressive modulus and ultimate strength along the axis of the scaffolds reached (464.0 +/- 36.0) MPa and (5.6 +/- 0.8) MPa respectively. The results of animal test indicated that the trabeculae of these scaffolds were covered by a layer of new bone after 10 weeks of operation.</p><p><b>CONCLUSION</b>Porous BCP scaffolds have been produced with oriented microarchitectural features designed to facilitate vascular invasion and cellular attachment and with initial mechanical properties comparable to those of trabecular bone.</p>