Dark Agouti rat donor hind limbs were orthotopically transplanted into Lewis rat recipients to verify the effects of bone marrow mesenchymal stem cells on neural regeneration and functional recovery of allotransplante...Dark Agouti rat donor hind limbs were orthotopically transplanted into Lewis rat recipients to verify the effects of bone marrow mesenchymal stem cells on neural regeneration and functional recovery of allotransplanted limbs in the microenvironment of immunotolerance, bone marrow mesenchymal stem cells were intramuscularly （gluteus maximus） injected with FK506 （tacrolimus） daily, and were transplanted to the injured nerves. Results indicated that the allograft group not receiving therapy showed severe rejection, with transplanted limbs detaching at 10 days after transplantation with complete necrosis. The number of myelinated axons and Schwann cells in the FK506 and FK506 ＋ bone marrow mesenchymal stem cells groups were significantly increased. We observed a lesser degree of gastrocnemius muscle degeneration, and increased polymorphic fibers along with other pathological changes in the FK506 ＋ bone marrow mesenchymal stem cells group. The FK506 ＋ bone marrow mesenchymal stem cells group showed significantly better recovery than the autograft and FK506 groups. The results demonstrated that FK506 improved the immune microenvironment. FK506 combined with bone marrow mesenchymal stem cells significantly promoted sciatic nerve regeneration, and improved sensory recovery and motor function in hind limb allotransplant.展开更多
In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indic...In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indicate that treatment with 1,25-dihydroxyvitamin D3 had minor effects in non-diabetic rats. The same treatment in streptozotocin-induced diabetic rats, although it did not correct the hyperglycemia and hypoinsulinemia induced by the diabetes, caused other actions that could mean beneficial effects on the amelioration of diabetes e.g., it avoided body weight loss, increased calcium and phosphorus plasma levels, and corrected the over-expression of the insulin receptor mRNA species of 9.5 and 7.5 Kb present in the hind limb muscle and heart of these animals. These genomic 1,25-dihydroxyvitamin D3 effects could involve transcriptional mechanisms of repression mediated by vitamin D response elements in the rat insulin receptor gene promoter. Using computer analysis of this promoter, we propose the -249/-235 bp VDRE (5’GGGTGACCCGGGGTT3’) with a pyrimidine (T) in the (+7) position of the3’half-site as the best candidate for negative control by 1,25-dihydroxy-vitamin D3. In addition, posttranscriptional mechanisms of regulation could also be implicated. Thus, computer inspection of the5’untranslated region of the rat insulin receptor pre-mRNA indicated the presence of a virtual internal ribosome entry segment whereas the computer inspection of the3’untranslated region localized various destabilizing sequences, including various AU-rich elements. We propose that through these virtual cis-regulatory sequences, 1,25-dihydroxyvitamin D3 could control the translation and stability of insulin receptor mRNA species in the hind limb muscle and heart of diabetic rats.展开更多
The goat’s hind limbs play an important role in dampening vibrations caused by ground impact during movement.Inspired by the unique structure of their hind limbs,a novel bionic limb vibration isolator has been develo...The goat’s hind limbs play an important role in dampening vibrations caused by ground impact during movement.Inspired by the unique structure of their hind limbs,a novel bionic limb vibration isolator has been developed to suppress low-frequency vibrations.It consists of the base,the carrying platform,four bionic legs and so on.The bionic legs are made up of rods of varying lengths and springs in different directions to imitate the various shapes of bones such as the femur and patella of the hind limbs of goats and developed muscles such as the biceps and quadriceps.The bionic device was found to have excellent nonlinear stiffness through statics analysis,and could be flexibly adjusted to the work range and load capacity.The bionic vibration isolator offers lower natural frequencies(2.3 Hz),better vibration isolation effect and a wider vibration isolation band than conventional linear vibration isolator.The bionic device can effectively suppress vibrations above 3.2 Hz and reduce the amplitude of random vibrations to more than 90%.In addition,compared to similar bionic vibration isolation devices,the bionic isolator achieves excellent load-bearing capacity in a smaller size,which facilitates its application in practical production.展开更多
Background Diabetes mellitus （DM） is a common disease accompanied with a high incidence of hind limb ischemia （HLI）.In recent years,numerous studies demonstrated that endothelial progenitor cells （EPCs） are invo...Background Diabetes mellitus （DM） is a common disease accompanied with a high incidence of hind limb ischemia （HLI）.In recent years,numerous studies demonstrated that endothelial progenitor cells （EPCs） are involved in angiogenesis and maintenance of vascular integrity following HLI.On the other side,it has been proved that Astragalus polysaccharide （APS） could promote angiogenesis.In the present study,we aimed to evaluate the effect of APS and EPCs on enhancing angiogenesis after experimental HLI caused by femoral artery ligation in rats with streptozotocin （STZ）-induced diabetes.Methods Rats （n=110） were randomly assigned to the following groups：sham group,ischemia group,APS group,EPCs group and APS＋EPCs group.APS,EPCs or an equal volume of vehicle was administered intramuscularly after HLI induction,and 6 rats were assessed by angiography at 28 days after induction of HLI,6 rats were sacrificed at the same time point to take histological studies,biochemical tests were also performed at that point in the rest rats.Results APS or EPCs treatment induced an increase,respectively,in the protein expression of vascular endothelial growth factor （VEGF） （36.61%,61.59%）,VEGF receptor-1 （VEGFR-1） （35.50%,57.33%）,VEGFR-2 （31.75%,41.89%）,Angiopoietin-1 （Ang-1） （37.57%,64.66%） and Tie-2 （42.55%,76.94%） （P 〈0.05）,after HLI injury.And combined therapy of APS and EPCs enhanced the effort of angiogenesis after HLI induction in diabetic rats,through elevating protein expression of VEGF （99.67%）,VEGFR-1 （105.33%）,VEGFR2 （72.05%）,Ang-1 （114.30%） and Tie-2 （111.87%） （P〈0.05）.Similarly,mRNA expression of VEGF,VEGFR-1,VEGFR2,Ang-1,Tie-2 also show similar trends as well as protein expression （P〈0.05）.Conclusion APS or EPCs could enhance angiogenesis,and the combined treatment leads to better effort,at least,partially via VEGFNEGFR and Ang-1/Tie-2 signaling pathway.展开更多
基金the National Natural Science Foundation of China,No.30801171，the Natural Science Foundation of Hebei Province,No.C2009001013 and No.H2012406015
文摘Dark Agouti rat donor hind limbs were orthotopically transplanted into Lewis rat recipients to verify the effects of bone marrow mesenchymal stem cells on neural regeneration and functional recovery of allotransplanted limbs in the microenvironment of immunotolerance, bone marrow mesenchymal stem cells were intramuscularly （gluteus maximus） injected with FK506 （tacrolimus） daily, and were transplanted to the injured nerves. Results indicated that the allograft group not receiving therapy showed severe rejection, with transplanted limbs detaching at 10 days after transplantation with complete necrosis. The number of myelinated axons and Schwann cells in the FK506 and FK506 ＋ bone marrow mesenchymal stem cells groups were significantly increased. We observed a lesser degree of gastrocnemius muscle degeneration, and increased polymorphic fibers along with other pathological changes in the FK506 ＋ bone marrow mesenchymal stem cells group. The FK506 ＋ bone marrow mesenchymal stem cells group showed significantly better recovery than the autograft and FK506 groups. The results demonstrated that FK506 improved the immune microenvironment. FK506 combined with bone marrow mesenchymal stem cells significantly promoted sciatic nerve regeneration, and improved sensory recovery and motor function in hind limb allotransplant.
基金This work was supported by research Funds from the Ministerio de Ciencia e Innovación(SAF2009-12671).
文摘In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indicate that treatment with 1,25-dihydroxyvitamin D3 had minor effects in non-diabetic rats. The same treatment in streptozotocin-induced diabetic rats, although it did not correct the hyperglycemia and hypoinsulinemia induced by the diabetes, caused other actions that could mean beneficial effects on the amelioration of diabetes e.g., it avoided body weight loss, increased calcium and phosphorus plasma levels, and corrected the over-expression of the insulin receptor mRNA species of 9.5 and 7.5 Kb present in the hind limb muscle and heart of these animals. These genomic 1,25-dihydroxyvitamin D3 effects could involve transcriptional mechanisms of repression mediated by vitamin D response elements in the rat insulin receptor gene promoter. Using computer analysis of this promoter, we propose the -249/-235 bp VDRE (5’GGGTGACCCGGGGTT3’) with a pyrimidine (T) in the (+7) position of the3’half-site as the best candidate for negative control by 1,25-dihydroxy-vitamin D3. In addition, posttranscriptional mechanisms of regulation could also be implicated. Thus, computer inspection of the5’untranslated region of the rat insulin receptor pre-mRNA indicated the presence of a virtual internal ribosome entry segment whereas the computer inspection of the3’untranslated region localized various destabilizing sequences, including various AU-rich elements. We propose that through these virtual cis-regulatory sequences, 1,25-dihydroxyvitamin D3 could control the translation and stability of insulin receptor mRNA species in the hind limb muscle and heart of diabetic rats.
基金This research was funded by the the Science and Technology Development Program of Jilin Province,China(Grant No.20230101117JC)National Natural Science Foundation of China(Grant No.51775234,91748211,51305157)the Science and Technology Development Program of Jilin Province,China(Grant No.20190302101GX,20180101090JC).
文摘The goat’s hind limbs play an important role in dampening vibrations caused by ground impact during movement.Inspired by the unique structure of their hind limbs,a novel bionic limb vibration isolator has been developed to suppress low-frequency vibrations.It consists of the base,the carrying platform,four bionic legs and so on.The bionic legs are made up of rods of varying lengths and springs in different directions to imitate the various shapes of bones such as the femur and patella of the hind limbs of goats and developed muscles such as the biceps and quadriceps.The bionic device was found to have excellent nonlinear stiffness through statics analysis,and could be flexibly adjusted to the work range and load capacity.The bionic vibration isolator offers lower natural frequencies(2.3 Hz),better vibration isolation effect and a wider vibration isolation band than conventional linear vibration isolator.The bionic device can effectively suppress vibrations above 3.2 Hz and reduce the amplitude of random vibrations to more than 90%.In addition,compared to similar bionic vibration isolation devices,the bionic isolator achieves excellent load-bearing capacity in a smaller size,which facilitates its application in practical production.
基金This work was supported by grants from Zhejiang Provincial Natural Science Foundation of China （No.Y12H070014） and National Natural Science Foundation of China （No.30972592）.
文摘Background Diabetes mellitus （DM） is a common disease accompanied with a high incidence of hind limb ischemia （HLI）.In recent years,numerous studies demonstrated that endothelial progenitor cells （EPCs） are involved in angiogenesis and maintenance of vascular integrity following HLI.On the other side,it has been proved that Astragalus polysaccharide （APS） could promote angiogenesis.In the present study,we aimed to evaluate the effect of APS and EPCs on enhancing angiogenesis after experimental HLI caused by femoral artery ligation in rats with streptozotocin （STZ）-induced diabetes.Methods Rats （n=110） were randomly assigned to the following groups：sham group,ischemia group,APS group,EPCs group and APS＋EPCs group.APS,EPCs or an equal volume of vehicle was administered intramuscularly after HLI induction,and 6 rats were assessed by angiography at 28 days after induction of HLI,6 rats were sacrificed at the same time point to take histological studies,biochemical tests were also performed at that point in the rest rats.Results APS or EPCs treatment induced an increase,respectively,in the protein expression of vascular endothelial growth factor （VEGF） （36.61%,61.59%）,VEGF receptor-1 （VEGFR-1） （35.50%,57.33%）,VEGFR-2 （31.75%,41.89%）,Angiopoietin-1 （Ang-1） （37.57%,64.66%） and Tie-2 （42.55%,76.94%） （P 〈0.05）,after HLI injury.And combined therapy of APS and EPCs enhanced the effort of angiogenesis after HLI induction in diabetic rats,through elevating protein expression of VEGF （99.67%）,VEGFR-1 （105.33%）,VEGFR2 （72.05%）,Ang-1 （114.30%） and Tie-2 （111.87%） （P〈0.05）.Similarly,mRNA expression of VEGF,VEGFR-1,VEGFR2,Ang-1,Tie-2 also show similar trends as well as protein expression （P〈0.05）.Conclusion APS or EPCs could enhance angiogenesis,and the combined treatment leads to better effort,at least,partially via VEGFNEGFR and Ang-1/Tie-2 signaling pathway.
基金Supported by National Natural Science Foundation of China(51147008)Specialized Research Fund for the Doctoral Program of Higher Education(20126102110055)
