The volatile flavor and the antioxidant properties of a novel chrysanthemum rice wine during natural aging.

Chrysanthemum morifolium cv. Fubaiju, a traditional tea in southern China with high nutritional and health functions was used in this study. Optimized production conditions of a novel chrysanthemum rice wine (FRW) were obtained by the Box-Behnken design response surface experiment. FRW with best sensory quality was developed with 0.68% chrysanthemum, 0.79% Jiuqu and 0.81:1 liquid-to-solid ratio. Compared with rice wine (RW) control, the total phenolic and flavonoid contents, as well as antioxidant activity of the FRW increased significantly. GC-MS analysis showed that more flavor compounds including alcohols, aldehydes, acids, and esters were detected in FRW. During the aging process, it was found that the antioxidant substances, the antioxidant activity and the flavor substances decreased, with the wine body tending to be homogenized. After 6 months of storage, overall sensory quality of FRW was more harmonious, with special nectar taste, which dramatically improved the flavor characteristics and functionality compared with traditional RW.

A novel tissue engineered nerve graft constructed with autologous vein and nerve microtissue repairs a long-segment sciatic nerve defect.

Veins are easy to obtain, have low immunogenicity, and induce a relatively weak inflammatory response. Therefore, veins have the potential to be used as conduits for nerve regeneration. However, because of the presence of venous valves and the great elasticity of the venous wall, the vein is not conducive to nerve regeneration. In this study, a novel tissue engineered nerve graft was constructed by combining normal dissected nerve microtissue with an autologous vein graft for repairing 10-mm peripheral nerve defects in rats. Compared with rats given the vein graft alone, rats given the tissue engineered nerve graft had an improved sciatic static index, and a higher amplitude and shorter latency of compound muscle action potentials. Furthermore, rats implanted with the microtissue graft had a higher density and thickness of myelinated nerve fibers and reduced gastrocnemius muscle atrophy compared with rats implanted with the vein alone. However, the tissue engineered nerve graft had a lower ability to repair the defect than autogenous nerve transplantation. In summary, although the tissue engineered nerve graft constructed with autologous vein and nerve microtissue is not as effective as autologous nerve transplantation for repairing long-segment sciatic nerve defects, it may nonetheless have therapeutic potential for the clinical repair of long sciatic nerve defects. This study was approved by the Experimental Animal Ethics Committee of Chinese PLA General Hospital (approval No. 2016-x9-07) on September 7, 2016.

Bioinformatic analysis of cytokine expression in the proximal and distal nerve stumps after peripheral nerve injury.

In our previous study, we investigated the dynamic expression of cytokines in the distal nerve stumps after peripheral nerve injury using microarray analysis, which can characterize the dynamic expression of proteins. In the present study, we used a rat model of right sciatic nerve transection to examine changes in the expression of cytokines at 1, 7, 14 and 28 days after injury using protein microarray analysis. Interleukins were increased in the distal nerve stumps at 1-14 days post nerve transection. However, growth factors and growth factor-related proteins were mainly upregulated in the proximal nerve stumps. The P-values of the inflammatory response, apoptotic response and cell-cell adhesion in the distal stumps were higher than those in the proximal nerve stumps, but the opposite was observed for angiogenesis. The number of cytokines related to axons in the distal stumps was greater than that in the proximal stumps, while the percentage of cytokines related to axons in the distal stumps was lower than that in the proximal nerve stumps. Visualization of the results revealed the specific expression patterns and differences in cytokines in and between the proximal and distal nerve stumps. Our findings offer potential therapeutic targets and should help advance the development of clinical treatments for peripheral nerve injury. Approval for animal use in this study was obtained from the Animal Ethics Committee of the Chinese PLA General Hospital on September 7, 2016 (approval No. 2016-x9-07).

Association between glaucoma and the risk of Alzheimer's disease: A systematic review of observational studies.

To address inconsistency as well as investigate the relationship between glaucoma and the risk of Alzheimer's disease (AD). We systematically conducted this meta-analysis based on observational studies published up to 15 January 2018, identified from PubMed and Web of Science. Two team members independently extracted the data and assessed the quality of each included study. Summary relative risk (RR) and 95% confidence intervals (CIs) were calculated using a random-effects model. Eight observational studies with 6870 AD cases were included. The majority of these studies (n = 6) were graded as low risk according to the Newcastle-Ottawa Quality Assessment Scale. Individuals diagnosed with glaucoma, compared to those who were not, had an increased risk of AD (RR = 1.52; 95% CI: 1.41-1.63; I2  = 97%, p < 0.001). A significant finding was also observed for primary open-angle glaucoma (RR = 1.52; 95% CI: 1.41-1.63; I2  = 97%, p < 0.001). However, when stratified by study design, only the case-control studies (RR = 1.08; 95% CI: 0.89-1.31; I2  = 37.3%, p = 0.207) yielded significant results, while the cohort studies did not (RR = 1.08; 95% CI: 0.89-1.31; I2  = 97.7%, p < 0.001). Of note, our meta-regression analysis suggested that study design might be a source of heterogeneity (p = 0.009). Additionally, a significantly positive association was observed when the analyses were restricted to Asia (RR = 2.03; 95% CI: 1.02-4.07). There was no significant publication bias in these analyses. Recent evidence suggests that glaucoma may increase the risk of AD. Additional cohort studies are needed to confirm these findings and to have improved knowledge on the true nature of this association.

Extracellular matrix from human umbilical cord-derived mesenchymal stem cells as a scaffold for peripheral nerve regeneration.

The extracellular matrix, which includes collagens, laminin, or fibronectin, plays an important role in peripheral nerve regeneration. Recently, a Schwann cell-derived extracellular matrix with classical biomaterial was used to mimic the neural niche. However, extensive clinical use of Schwann cells remains limited because of the limited origin, loss of an autologous nerve, and extended in vitro culture times. In the present study, human umbilical cord-derived mesenchymal stem cells (hUCMSCs), which are easily accessible and more proliferative than Schwann cells, were used to prepare an extracellular matrix. We identified the morphology and function of hUCMSCs and investigated their effect on peripheral nerve regeneration. Compared with a non-coated dish tissue culture, the hUCMSC-derived extracellular matrix enhanced Schwann cell proliferation, upregulated gene and protein expression levels of brain-derived neurotrophic factor, glial cell-derived neurotrophic factor, and vascular endothelial growth factor in Schwann cells, and enhanced neurite outgrowth from dorsal root ganglion neurons. These findings suggest that the hUCMSC-derived extracellular matrix promotes peripheral nerve repair and can be used as a basis for the rational design of engineered neural niches.

Comparisons of Emu Necrotic Femoral Head Micro Structure Repaired in Two Different Methods.

OBJECTIVE: To compare emu necrotic femoral head micro structure repaired in two different methods. METHODS: 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. RESULTS: 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). CONCLUSION: Different repair methods make reconstructed femoral head weight bearing area have different bone structure and bone mineral density, along with different bone trabecular quality.

MicroRNAs' Involvement in Osteoarthritis and the Prospects for Treatments.

Osteoarthritis (OA) is a chronic disease and its etiology is complex. With increasing OA incidence, more and more people are facing heavy financial and social burdens from the disease. Genetics-related aspects of OA pathogenesis are not well understood. Recent reports have examined the molecular mechanisms and genes related to OA. It has been realized that genetic changes in articular cartilage and bone may contribute to OA's development. Osteoclasts, osteoblasts, osteocytes, and chondrocytes in joints must express appropriate genes to achieve tissue homeostasis, and errors in this can cause OA. MicroRNAs (miRNAs) are small noncoding RNAs that have been discovered to be overarching regulators of gene expression. Their ability to repress many target genes and their target-binding specificity indicate a complex network of interactions, which is still being defined. Many studies have focused on the role of miRNAs in bone and cartilage and have identified numbers of miRNAs that play important roles in regulating bone and cartilage homeostasis. Those miRNAs may also be involved in the pathology of OA, which is the focus of this review. Future studies on the role of miRNAs in OA will provide important clues leading to a better understanding of the mechanism(s) of OA and, more particularly, to the development of therapeutic targets for OA.

Application of bone marrow mesenchymal stem cells to the treatment of osteonecrosis of the femoral head.

Osteonecrosis of the femoral head (ONFH) is a type of common and refractory disease in the orthopedic clinic that is primarily caused by a partial obstruction of the blood supply to the femoral head, resulting in a series of pathological processes. Mesenchymal stem cells (MSCs) comprise a mixture of various stem cells in myeloid tissue with multipotential differentiation capacity. They can differentiate into bone cells under specific conditions and can be used to treat ONFH through cell transplantation. This review summarizes research on MSCs in the field of ONFH in recent years, reveals the inner characteristics of MSCs, describes their potential to treat osteonecrosis disease, and analyzes the existing challenges of using MSCs in clinical applications.

Effect of cervus and cucumis peptides on osteoblast activity and fracture healing in osteoporotic bone.

Osteoporosis is associated with delayed and/or reduced fracture healing. As cervus and cucumis are the traditional Chinese treatments for rheumatoid arthritis, we investigated the effect of supplementation of these peptides (CCP) on bone fracture healing in ovariectomized (OVX) osteoporotic rats in vitro and in vivo. CCP enhanced osteoblast proliferation and increased alkaline phosphatase activity, matrix mineralization, and expression of runt-related transcription factor 2 (Runx2), bone morphogenetic protein 4 (BMP4), and osteopontin. In vivo, female Sprague-Dawley rats underwent ovariectomy and the right femora were fractured and fixed by intramedullary nailing 3 months later. Rats received intraperitoneal injections of either CCP (1.67 mg/kg) or physiological saline every day for 30 days. Fracture healing and callus formation were evaluated by radiography, micro-CT, biomechanical testing, and histology. At 12 weeks after fracture, calluses in CCP-treated bones showed significantly higher torsional strength and greater stiffness than control-treated bones. Bones in CCP-treated rats reunified and were thoroughly remodeled, while two saline-treated rats showed no bone union and incomplete remodeling. Taken together, these results indicate that use of CCP after fracture in osteoporotic rats accelerates mineralization and osteogenesis and improves fracture healing.

[Study of animal model of osteonecrosis induced by local ethanol injection in emu].

OBJECTIVE: To establish a new animal model of osteonecrosis of the femoral head by local ethanol injection in emu. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Bone microstructure and regional distribution of osteoblast and osteoclast activity in the osteonecrotic femoral head.

OBJECTIVE: To detect and compare the bone microstructure and osteoblast and osteoclast activity in different regions of human osteonecrotic femoral heads. METHODS: Osteonecrotic femoral heads were obtained from 10 patients (6 males, 4 females; Ficat IV) undergoing total hip arthroplasty between 2011 and 2013. The samples were divided into subchondral bone, necrotic, sclerotic, and healthy regions based on micro-computed tomography (CT) images. The bone microstructure, micromechanics, and osteoblast and osteoclast activity were assessed using micro-CT, pathology, immunohistochemistry, nanoindentation, reverse transcription polymerase chain reaction (RT-PCR), tartrate-resistant acid phosphatase staining and Western blotting. RESULTS: (1) The spatial structure of the bone trabeculae differed markedly in the various regions of the osteonecrotic femoral heads. (2) The elastic modulus and hardness of the bone trabeculae in the healthy and necrotic regions did not differ significantly (P >0.05). (3) The subchondral bone and necrotic region were positive on TRAP staining, while the other regions were negative. (4) On immunohistochemical staining, RANK and RANKL staining intensities were increased significantly in the subchondral bone and necrotic region compared with the healthy region, while RUNX2 and BMP2 staining intensities were increased significantly in the sclerotic region compared with the necrotic region. (5) OPG, RANK, RANKL, RUNX2, BMP2, and BMP7 protein levels were greater in the necrotic and sclerotic region than in subchondral bone and the healthy region. CONCLUSION: The micromechanical properties of bone trabeculae in the necrotic region did not differ significantly from the healthy region. During the progress of osteonecrosis, the bone structure changed markedly. Osteoclast activity increased in subchondral bone and the necrotic region while osteoblast activity increased in the sclerotic region. We speculate that the altered osteoblast and osteoclast activity leads to a reduction in macroscopic mechanical strength.

Basic research and clinical applications of bisphosphonates in bone disease: what have we learned over the last 40 years?

It is now 40 years since bisphosphonates (BPs) were first used in the clinic. So, it is timely to provide a brief review of what we have learned about these agents in bone disease. BPs are bone-specific and have been classified into two major groups on the basis of their distinct molecular modes of action: amino-BPs and non-amino-BPs. The amino-BPs are more potent and they inhibit farnesyl pyrophosphate synthase (FPPS), a key enzyme of the mavalonate/cholesterol biosynthetic pathway, while the non-amino-BPs inhibit osteoclast activity, by incorporation into non-hydrolyzable analogs of ATP. Both amino-BPs and non-amino-BPs can protect osteoblasts and osteocytes against apoptosis. The BPs are widely used in the clinic to treat various diseases characterized by excessive bone resorption, including osteoporosis, myeloma, bone metastasis, Legg-Perthes disease, malignant hyperparathyroidism, and other conditions featuring bone fragility. This review provides insights into some of the adverse effects of BPs, such as gastric irritation, osteonecrosis of the jaw, atypical femoral fractures, esophageal cancer, atrial fibrillation, and ocular inflammation. In conclusion, this review covers the biochemical and molecular mechanisms of action of BPs in bone, particularly the discovery that BPs have direct anti-apoptotic effects on osteoblasts and osteocytes, and the current situation of BP use in the clinic.

[Combined effects of NEL-like type 1 gene and zoledronate in preventing collapse of the femoral head].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

In vitro cartilage production using an extracellular matrix-derived scaffold and bone marrow-derived mesenchymal stem cells.

BACKGROUND: Cartilage repair is a challenging research area because of the limited healing capacity of adult articular cartilage. We had previously developed a natural, human cartilage extracellular matrix (ECM)-derived scaffold for in vivo cartilage tissue engineering in nude mice. However, before these scaffolds can be used in clinical applications in vivo, the in vitro effects should be further explored. METHODS: We produced cartilage in vitro using a natural cartilage ECM-derived scaffold. The scaffolds were fabricated by combining a decellularization procedure with a freeze-drying technique and were characterized by scanning electron microscopy (SEM), micro-computed tomography (micro-CT), histological staining, cytotoxicity assay, biochemical and biomechanical analysis. After being chondrogenically induced, the induction results of BMSCs were analyzed by histology and Immunohisto-chemistry. The attachment and viability assessment of the cells on scaffolds were analyzed using SEM and LIVE/DEAD staining. Cell-scaffold constructs cultured in vitro for 1 week and 3 weeks were analyzed using histological and immunohistochemical methods. RESULTS: SEM and micro-CT revealed a 3-D interconnected porous structure. The majority of the cartilage ECM was found in the scaffold following the removal of cellular debris, and stained positive for safranin O and collagen II. Viability staining indicated no cytotoxic effects of the scaffold. Biochemical analysis showed that collagen content was (708.2-44.7) µg/mg, with GAG (254.7 ± 25.9) µg/mg. Mechanical testing showed the compression moduli (E) were (1.226 ± 0.288) and (0.052 ± 0.007) MPa in dry and wet conditions, respectively. Isolated canine bone marrow-derived stem cells (BMSCs) were induced down a chondrogenic pathway, labeled with PKH26, and seeded onto the scaffold. Immunofluorescent staining of the cell-scaffold constructs indicated that chondrocyte-like cells were derived from seeded BMSCs and excreted ECM. The cell-scaffold constructs contained pink, smooth and translucent cartilage-like tissue after 3 weeks of culture. We observed evenly distributed cartilage ECM proteoglycans and collagen type II around seeded BMSCs on the surface and inside the pores throughout the scaffold. CONCLUSION: This study suggests that a cartilage ECM scaffold holds much promise for in vitro cartilage tissue engineering.

9p21 polymorphisms increase the risk of peripheral artery disease in the Han Chinese population.

OBJECTIVE: A case-control study to investigate the association of the 9p21 single nucleotide polymorphisms (SNPs) rs10757274 and rs10757278 (known to be associated with coronary artery disease [CAD] risk) with peripheral arterial disease (PAD), in a Han Chinese population. METHODS: The rs10757274 and rs10757278 genotypes of patients with PAD, and age- and sex-matched control subjects, were determined. Multivariate unconditional logistic regression analyses were performed, with adjustments for age, sex, hypertension, dyslipidaemia, diabetes and smoking status. RESULTS: The study included 420 patients with PAD and 418 control subjects. Variant forms of both SNPs were associated with increased risk of PAD in the total study population, when excluding patients with CAD or stroke (additive genetic model). The GG haplotype increased the risk of PAD, but this association did not remain significant after further sensitivity analysis. Both SNPs were associated with PAD risk in patients aged <65 years, but not in those aged ≥ 65 years (additive model). CONCLUSIONS: 9p21 is associated with PAD. When stratified according to age, 9p21 increases PAD risk in individuals aged <65 years, but not in those aged ≥ 65 years.

Reconstruction of the medial patellofemoral ligament using hamstring tendon graft with different methods: a biomechanical study.

OBJECTIVE: To measure the tensile strength of the normal medial patellofemoral ligament (MPFL), and evaluate the biomechanics of different fixation methods of the hamstring tendon graft on the patella. METHODS: Eight fresh cadaver knees were prepared by isolating the patella, leaving only the MPFL as its attachment to the medial condyle of femur. The MPFL was reconstructed by three different methods: four-suture fixation, anchors-single suture fixation, and anchors-double suture fixation. The tensile strength and the elongation of the normal MPFL and the tendon grafts were measured. RESULTS: The tensile strength of the four-suture fixation group (234.86±49.02 N) was stronger than that of the normal MPFL (146.91±25.30 N, P=0.0014) and the anchors-single suture group (159.17±49.07 N, P=0.0077), while weaker than that of the anchors-double suture group (314.74±78.46 N, P=0.0052) CONCLUSIONS: With regard to the tensile strength, the four-suture fixation method is reliable for clinical use. Compared with the anchor-suture method, the four-suture fixation method which has no specific implants is more economical, convenient and efficient.

Effect and mechanism of zoledronate on prevention of collapse in osteonecrosis of the femoral head.

OBJECTIVE: To observe the effect and mechanism of zoledronate on prevention of collapse in an animal model of osteonecrosis. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[A new animal model of osteonecrosis induced by focal alternative cooling and heating insults].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

[In vitro cartilage tissue engineering with cartilage extracellular matrix-derived porous scaffolds and bone marrow mesenchymal stem cells].

OBJECTIVE: To develop a novel cartilage ECM-derived porous scaffold (CEDPS) and investigate the attachment, proliferation and distribution of bone marrow mesenchymal stem cells (BMSCs) cultured in vitro within the scaffolds. METHODS: Cartilage microfilaments were prepared after pulverization and gradient centrifugation and prepared into suspension after acellularization treatment. The scaffolds were examined by histological staining, scanning electron microscope (SEM), biochemical and biomechanical analysis. After labeling with PKH26, the canine BMSCs were seeded onto the scaffolds. The attachment, proliferation and differentiation of cells were observed by inverted fluorescent microscope and SEM. RESULTS: On histology, most extracellular matrices were retained in the scaffold after the removal of cell fragments. Safranin O staining and immunofluorescence examination with collagen II antibodies provided positive results. Biochemical analysis showed that the collagen content was (708.2 ± 44.7) µg/mg, glycosaminoglycan (254.7 ± 25.9) µg/mg and DNA (0.021 ± 0.007) µg/mg. Mechanical testing showed the compression moduli (E) were (1.226 ± 0.288) and (0.052 ± 0.007) MPa under dry and wet conditions respectively. Inverted fluorescent microscope and SEM showed moderate cell adhesion, chondrocyte-like morphology and matrix synthesis around cells. CONCLUSION: The CEDPS retains most extracellular matrices after a thorough decellularization so as to possess an excellent microstructure with ideal biomechanical characteristics and a good biocompatibility. Thus it is a suitable candidate as an alternative cell-carrier for cartilage tissue engineering. Chondrogenic BMSCs and CEDPS may be used to construct cartilage-like tissue in vitro.

Efficacy of intravitreal captopril on oxygen-induced retinopathy in mice.

AIM: To study the inhibitory effect of intravitreal captopril on oxygen-induced retinopathy (OIR) in mice. METHODS: Eighty postnatal day (P)7 C57BL/6J mice were randomly divided into treated group and control group with forty mice in each group. The mice were exposed to 75% ± 2% oxygen for 5 days (P7-P11) and then returned to room air for 5 days (P12-P17) to induce retinal neovascularization (RNV). Beginning on P12, the mice in treated group received daily intravitreal injections of captopril (3.0mL/kg), while those in control group received daily intravitreal injections of phosphate-buffered saline (PBS) (3.0mL/kg) through P17. After anesthetized at P17, one eye was chosen randomly as experimental eye and were enucleated. RNV was examined by Adenosine diphosphate-ase (ADPase) stained retina flat-mounts and was quantitated histologically by counting the neovascular endothelial cell nuclei anterior to inner limiting membrane (ILM). The expressions of matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) were measured by immunohistochemical method. RESULTS: Comparing with control group, more regular distributions, better branch and reduced density of RNV were observed in eyes of treated group. The number of neovascular cell nuclei was less in treated group than that in control group (t=6.135, P<0.01). Stain of MMP-2 and VEGF was weaker in treated group than that in control group. CONCLUSION: The results indicate that captopril can significantly inhibit RNV in OIR mice.