BACKGROUND:The plateau environment affects the immune function and metabolic status of patients with osteomyelitis,leading to acceleration or complication of the disease process.The construction of effective and stable animal models of chronic osteomyelitis is essential for experimental studies of chronic osteomyelitis.OBJECTIVE:To establish a sheep model of chronic osteomyelitis in plateau regions for toxicity assessment and therapeutic research.METHODS:Fifteen healthy sheep were selected in this study.Sodium morrhuate and Staphylococcus aureus suspension were injected into the medullary cavity of the middle segment of the tibia to establish the chronic osteomyelitis model.General observation,body mass and temperature monitoring,blood infection index detection,radiological scoring,and microbial culture were performed for evaluation and analysis.RESULTS AND CONCLUSION:(1)Local tissue swelling and lameness of the affected leg were observed in all sheep in the early stage after modeling,accompanied by varying degrees of anorexia.A slight decrease in body mass was observed in sheep 1 week after modeling,while no significant changes in body temperature were observed.(2)The erythrocyte sedimentation rate significantly accelerated 4 days after modeling(P<0.05)and gradually returned to normal levels after 1 month.The white blood cell count showed a significant increase within 4 days after modeling and returned to normal after 1 week.The level of C-reactive protein increased significantly after modeling(P<0.05)and remained significantly higher than normal until the end of the experiment(P<0.05).(3)Fifteen sheep exhibited typical radiological manifestations of osteomyelitis,including unclear boundaries,irregular osteolytic lesions,and low-density bright absorption areas with interspersed necrotic bone fragments of increased and uneven density.Different degrees of periosteal reaction were observed in the cortex near the lesion.(4)Thirteen sheep were cultured for a single strain of Staphylococcus aureus,while two sheep were cultured for Staphylococcus aureus and Escherichia coli.These findings indicate that a reliable chronic osteomyelitis animal model of sheep tibia can be successfully established in plateau regions by injecting an appropriate amount of Staphylococcus aureus suspension into the medullary cavity of sheep,combined with local implantation of foreign cotton thread and sodium morrhuate.

BACKGROUND:The plateau environment affects the immune function and metabolic status of patients with osteomyelitis,leading to acceleration or complication of the disease process.The construction of effective and stable animal models of chronic osteomyelitis is essential for experimental studies of chronic osteomyelitis.OBJECTIVE:To establish a sheep model of chronic osteomyelitis in plateau regions for toxicity assessment and therapeutic research.METHODS:Fifteen healthy sheep were selected in this study.Sodium morrhuate and Staphylococcus aureus suspension were injected into the medullary cavity of the middle segment of the tibia to establish the chronic osteomyelitis model.General observation,body mass and temperature monitoring,blood infection index detection,radiological scoring,and microbial culture were performed for evaluation and analysis.RESULTS AND CONCLUSION:(1)Local tissue swelling and lameness of the affected leg were observed in all sheep in the early stage after modeling,accompanied by varying degrees of anorexia.A slight decrease in body mass was observed in sheep 1 week after modeling,while no significant changes in body temperature were observed.(2)The erythrocyte sedimentation rate significantly accelerated 4 days after modeling(P<0.05)and gradually returned to normal levels after 1 month.The white blood cell count showed a significant increase within 4 days after modeling and returned to normal after 1 week.The level of C-reactive protein increased significantly after modeling(P<0.05)and remained significantly higher than normal until the end of the experiment(P<0.05).(3)Fifteen sheep exhibited typical radiological manifestations of osteomyelitis,including unclear boundaries,irregular osteolytic lesions,and low-density bright absorption areas with interspersed necrotic bone fragments of increased and uneven density.Different degrees of periosteal reaction were observed in the cortex near the lesion.(4)Thirteen sheep were cultured for a single strain of Staphylococcus aureus,while two sheep were cultured for Staphylococcus aureus and Escherichia coli.These findings indicate that a reliable chronic osteomyelitis animal model of sheep tibia can be successfully established in plateau regions by injecting an appropriate amount of Staphylococcus aureus suspension into the medullary cavity of sheep,combined with local implantation of foreign cotton thread and sodium morrhuate.

Objective To investigate the potential therapeutic efficacy of lentivirus-mediated artemin (ARTN) gene modified bone marrow mesenchymal stem cells (MSCs) transplantation on the rat model of Parkinson' s disease (PD) and the effects on expression of brain-related proteins.Methods MSCs were isolated and cultured in vitro,transfected by recombinant lentiviral vectors carrying ARTN gene.The PD rat model established by 6-hydroxydopamine (6-OHDA) was randomly divided into 5 groups:Sham group,PD group,MSCs group,MSCs transfected with empty lentiviral vectors transplanted (LV-MSCs)group and MSCs transfected with recombinant lentiviral vectors carrying ARTN gene transplanted (LVARTN-MSCs) group.The MSCs,LV-MSCs and LV-ARTN-MSCs groups were transplanted into the left striatum of each rat model of PD and ethology tests in every group were made with intraperitoneal injection of apomorphine (APO) 2,4,6,8 weeks after transplantation.The expression of tyrosine hydroxylase (TH) protein in substantia nigra (SN) was measured by Western blotting and immunohistochemistry,and immunofluorescence showed ARTN gene modified MSCs expression in rat brain tissue.The levels of dopamine (DA),dihydroxy-phenylacetic acid and homovanillic acid in striatum of each group were detected by high performance liquid chromatography.Results After injection of APO,rotation frequency decreased in LV-ARTN-MSCs group,i.e.(179.33 ± 10.74) circles/30 min vs (235.83 ± 18.95),(203.67 ±11.50) and (206.33 ± 11.86) circles/30 min in PD,MSCs and LV-MSCs groups (q =8.828,P ＜ 0.01;q =3.802,P ＜ 0.05;q =4.219,P ＜ 0.05).The percentage of TH-positive cells in SN after cell transplantation was increased significantly in LV-ARTN-MSCs group (64.05％ ± 5.49％) when compared with PD group (34.18％ ±3.35％),MSCs group (52.59％ ±4.48％) and LV-MSCs group (50.57％ ± 4.41％),respectively (q =13.280,5.135,6.028,all P ＜0.01).At the same time,TH protein in SN after cell transplantation was also increased obviously in LV-ARTN-MSCs group.ARTN gene modified MSCs can survive for at least 6 weeks in the rat brain of PD,mainly concentrated in the transplantation side of striatum.Eight weeks later,the levels of DA in striatum after cell transplantation were elevated significantly in MSCs group (2.34 ± 0.54),LV-MSCs group (2.28 ± 0.45) and LV-ARTN-MSCs group (2.28 ± 0.45)when compared with PD group (0.87 ± 0.07) (q =5.233,P ＜ 0.05;q =5.020,P ＜ 0.01;q =20.190,P ＜ 0.01),and LV-ARTN-MSCs group showed the most significant improvement.Conclusion ARTN gene modified bone marrow MSCs transplanted into the striatum of brain may have therapeutic effects on rat models of PD.

Objective To discuss the protective effect of Artemin (ARTN) on 6-hydroxydopamine (6-OHDA)-mediated neurotoxic injury,and the alternations of related proteins in Parkinson's disease (PD) model rats.Methods Bone marrow mesenchymal stem cells (MSCs) were isolated and cultured in vitro.After being transfected with recombinant lentiviral vectors carrying A RTN gene,MSCs stably expressed ARTN were chosen (Lv-ARTN-MSCs cells).The SH-SY5Y cells were treated with supematant of Lv-ARTN-MSCs prior to 6-OHDA treatment,and then,cell survival rate was measured by MTT assay and morphologic changes in cultured SH-SY5Y cells were observed by fluorescence microscope (Hochest33258 staining).PD rat models were established and randomly divided into four groups (n=6):PD group,MSCs group,Lv-MSCs group and Lv-ARTN-MSCs group; and sham-operated group (n=6) was also chosen.The PD,MSCs,Lv-MSCs and Lv-ARTN-MSCs groups were transplanted with 5 μL of saline,MSCs (1.0×l05 cell/5 μL),empty virus modified MSCs (1.0×105 cell/5 μL) and ARTN gene modified MSCs (1.0×105 cell/5 μL),respectively,into the left striatum; rats in the sham-operated group were injected with saline when rats in the other groups were received 6-OHDA injection (the same surgical procedures and coordinates).The expressions of tyrosine hydroxylase (TH) and dopamine transporter (DAT) in the striatum were measured by Western blotting.Results Western blotting indicated obvious ARTN protein expressions in the Lv-ARTN-MSCs groups.The supematant of Lv-ARTN-MSCs could effectively reduce the apoptosis rate induced by 6-OHDA; as compared with that of SH-SY5Y cells in the 6-OHDA group,the cell survival rate in the Lv-A R TN-MSCs group increased by 13.67％,with significant difference (P＜0.05).Eight weeks after transplantation,the levels of TH and DAT protein in the striatum were elevated significantly in MSCs group,Lv-MSCs group and Lv-ARTN-MSCs group as compared with those in the PD group (P＜0.05),and the Lv-ARTN-MSCs group showed the most significant improvement.Conclusion ARTN which is a secreted protein can protect dopaminergic neuron against 6-OHDA-induced toxicities in Parkinson's disease,and the mechanism might be related to the increased expressions of TH and DAT.