BACKGROUND:Distraction osteogenesis is one of the most important tissue engineering technologies. However, the exact signaling pathway controling mesenchymal stem cel-osteoblast lineage (MSC-OB) migration during distraction osteogenesis has not yet been elucidated. More efforts should be paid to make a ful understanding of the mechanism on MSC-OB lineage migration, which can improve the clinical efficacy of distraction osteogenesis.
OBJECTIVE:To evaluate the effects of mechanical stretch on the ability of MSC-OB mobility and expression of mammalian target of rapamycin (mTOR) signaling pathway as wel as matrix metaloproteinases (MMPs) in MSC-OB, and to make clear the mechanism by which controls MSC-OB migration during distraction osteogenesis.
METHODS:Twelve Sprague-Dawley rats were randomized into two groups: experimental group (n=6), anin vivo rat mandibular distraction osteogenesis model was established on the right side of rats; non-stretch group (n=6), only the mandibular resection was done but with no distraction osteogenesis. Immunohistochemical staining was used to detect phosphorylated mTOR expression in new osteotylus at 15 days after operation. In addition, an in vitro cel stretch model was made in the mandibular mesenchymal stem cels from healthy Sprague-Dawley rats under resting tension force (6%, 4 hours); no distraction was done in control group. The ability of MSC-OB mobility, the expression of mTOR, Raptor, p70S6K and MMPs were evaluated using experiment methods including immunohistochemistry staining, real-time PCR and scratch assay.
RESULTS AND CONCLUSION: The expression of phosphorylated mTOR in MSC-OB was upregulated in the mandibular bone calus of the stretch group than the non-stretch group (P < 0.05). In thein vitro experiments, MSC-OB applied with mechanical stretch (6%, 4 hours) showed elevated gene expression levels of mTOR, Raptor, p70S6K, MMP-2, MMP-9 and MMP-13 compared with the control group (0%, 4 hours). Meanwhile, MSC-OB in the experiment group (6%, 4 hours) showed a greater ability of mobility, as demonstrated by a farther distance after 48 hours of observation (P < 0.05). The present study suggests that the enhancement of MSC-OB mobility correlates with increase of the gene expression of MMPs and mTOR signaling pathway. Mechanical stretch may promote MSC-OB migration through activation of mTOR/MMPs signaling pathway.

Objective To study the effect of injured podocytes on glomerular maturation and its underlying mechanism in neonatal mice.Methods Single i.p.injection with puromycin aminonucleoside (PA,0.1 mg/g BW) was given to ICR neonatal mice at day 1 after birth (1 dpp). Littermates injected with normal saline (NS) were used as control.Animals were examined for urine protein,blood pressure,kidney weight/body weight (KW/BW),renal histology at 2,4,8,12, 30,60 and 90 dpp (n=6～9 for each group).Immunohistochemistry and quantitative RT-PCR were performed to examine the expression of WT-1,CD31,VEGF,Flk-1,Ang-1,Ang-2,Tie-1 and Tie-2.Results Mice with PA injection had lower kidney weight and body weight at all time points as well as lower KW/BW at 4,8,12 dpp when compared with NS controls.Electron microscopy revealed nearly complete foot process effacement and segmental microvillous transformation as early as 1 day after PA injection.PA-injected kidneys showed fewer capillary loops and decreased maturation index as well as less CD31-positive endothelium in cortical glomeruli at 12 dpp. Glomerular mesangial injury and developing glomerulosclerosis along with proteinuria were noted in PA-injected kidneys starting from 30 dpp.Significantly increased systolic blood pressure was detected at 60 dpp in PA mice.Compared with NS injection,PA injection significantly induced decreased mRNA expression of Flk-1 and Tie-2 as well as increased expression of Ang-1,without obvious changes of VEGF at 2 dpp.Conclusions Podocytes in neonatal kidney of ICR mice are susceptible to PA. Such podocyte injury can alter the expression of VEGF and angiopoietin system in glomeruli,leading to abnormal development of glomerular capillaries,and subsequent proteinuria,hypertension and glomerulosclerosis.

s:The chemical constituents of gliocladium roseum(called Y)accelerating the growth of famous medicin al plant Anoectochilus roxburghiiwas studied.Five comp ounds were separated by silica gel column chromatograph from this fungal mycelia and their structures were elu cidated by the data of IR,NMR,UV and MS.Compound I was 6,22-diene-3-hydroxy- 5,8-epidioxy ergosta,compound 2 is ergosterol,compound 3 is D-arabitol and com pound 4 is mannitol.

Objective To study the mode and clinical implications of onset of spontaneous tosade de pointes in the congenital long QT syndrome. Methods We reviewed electrocardiograms (ECGs) of 55 patients with congenital QT syndrome for syncope. Documentation of the onset of tosade de pointes was available for 16 patients. All these patients had "definitive long QT syndrome" by accepted clinical and ECG criteria. Results One hundren and forty-nine runs of tosade de pointes were documented in 16 patients,of whom,there were 130 runs of pause-dependent tosade de pointes. Conclusion Our results show that the pause-dependent tosade de pointes,which has been recognized as a hallmark of tosade de pointes in the acquired long QT syndrome,plays a major role in the genesis of tosade de pointes in the congenital long QT syndrome.

OBJECTIVETo observe the clinical manifestations of bullous retinal detachment and analyze the etiological factors.

METHODSA retrospective analysis of the clinical data was conducted in 22 patients with multifocal retinal pigment epitheliopathy (DRPE) and big bullous retinal detachment (BBRD), who were admitted between 2003 and 2008 in Zhongshan Ophthalmic Center with the diagnoses established by ocular fundus examination, fundus fluorescein angiography (FFA) and/or indocyanine green angiography (ICGA).

RESULTSThe patients included 15 men (68%) and 7 women (32%), with a mean age at the initial visit of 42 years, ranging from 25 to 64 years. Four patients (18%) received previously systemic corticosteroid therapy, and 2 of them used corticosteroids before retina detachment, 1 suffered progression of retinal detachment after corticosteroid therapy, and the other developed retinal detachment in the healthy eye during the therapy. Multifocal bullous retinal detachment was diagnosed as diffuse pigment epitheliopathy (DRPE) in 9 cases. Most of the 13 cases of big bullous retinal detachment had poor vision after operation and laser therapy.

CONCLUSIONBullous retinal detachment occurs most frequently in mid-life and more often in men than women. Abnormal retinal pigment epithelium (RPE) and hyperpermeability of the choroid vessels are associated with its occurrence. Systemic corticosteroid therapy and mental stress may induce and aggravate this disease. Early medication and laser therapy are effective, and surgical intervention may save only part of the vision in advanced cases.

Adult ; Female ; Fundus Oculi ; Humans ; Male ; Middle Aged ; Retinal Detachment ; diagnosis ; etiology ; pathology ; therapy ; Retrospective Studies

Objective To assess the clinical application of contrast-enhanced MR angiography using three-dimensional(3D)time-resolved imaging of contrast kinetics(CE-MRA 3D-TRICKS).Methods TRICKS is a high temporal resolution(2—6s)MR angiographic technique using a short TR(2.8— 4.0 ms)and TE(0.9—1.3 ms),partial echo sampling and the central part of the k-space being updated more frequently than the peripheral part of the k-space.Pre-contrast mask 3D images are first acquired and 15--20 sequential 3D images following bolus injection of Gd-DTPA are then acquired.Results Thirty patients underwent contrast-enhanced MR angiography using TRICKS.Twelve vertebral arteries were well displayed on TRICKS.Seven of them showed normal,bilateral vertebral artery stenosis was shown in 1 case, and unilateral vertebral artery stenosis was shown in 4 wth aecompaning ipsilateral carotid artery bifurcation stenosis in one case.Bilateral renal artery showed normal in 4 cases,and the artery in transplanted kidney showed normal in one case and stenosis in another case.The cerebral artery showed normal in 2 cases, sagittal sinus thrombosis was detected in one case and intracranial arteriovenous malformation in one case. Pulmonary artery displayed normal in 3 cases,pulmonary artery thrombosis was seen in one case and pulmonary sequestration's abnormal feeding artery and draining vein was revealed in one case.The feeding artery in left lower limb fibrolipoma was showed in one case.The radial-ulnar artery artificial fistula stenosis was seen in one case,and left antebrachium hemangioma was showed in one case.Conclusion TRICKS can clearly delineate the whole body vascular system and can reveal any vascular abnormality.It is convenient and with high successful rate,which make it the first method of choice in displaying vascular abnormality.

Objective To investigate the therapeutic effect of interleukin-2(IL-2)on experimental autoimmune encephalomyelitis(EAE)mice.Methods After establishment of the EAE(experimental autoimmune encephalomyelitis) mouse models with MOG35-55 polypeptides,the mice were grouped according to the neurological function score and divided into control group,EAE group and low dose IL-2 treatment group.A double blind method was used to evaluate the neuro-logical impairment in mice.On the 29th day,pathological experiments were carried out in the mice's brain and spinal cord, hematoxylin-eosin staining was used to evaluate the scoring of inflammatory cell infiltration and luxol fast blue staining was used to evaluate the scoring of demyelinating.The proportion of regulatory T cells(Treg)and NK cells(natural killer cell, NK)was detected by flow cytometry,and the immunohistochemical method was used to detect the expressions of glial fibril -lary acidic protein(GFAP)and myelin basic protein(MBP)in the spinal cord.Results Compared with the EAE group, the neurological function score, the inflammatory cell infiltration score and the demyelinating score of the low dose IL-2 treatment group were reduced.The proportion of Treg cells in the low dose IL-2 treatment group was significantly higher than that in the EAE group,and the proportion of NK cells in the low dose IL-2 treatment group was slightly higher than that in the EAE group The expression of GFAP and MBP was detected by immunohistochemistry.The expression level of GFAP in low dose IL-2 treatment group was significantly lower than that in the EAE group,while the expression level of MBP was higher than that in the EAE group.Conclusion Low dose IL-2 has significant therapeutic effect on EAE mice.

Objective:To determine whether ox-LDL (oxdized low-density lipoprotein) is highly deposited on the uremic vessel wall and its influence on the vascular remodeling. Methods: Segments of radial arteries were obtained from 21 uremic subjects during the operation of A-V fistula prior to hemodialysis. Segments of internal thoracic arteries of similar diameter were obtained from patients with benign chest tumors as control.The vascular lesions and ox-LDL, CD68,MCP-1, eNOS,ET-1, PCNA,FN on the vessel wall were determined by means of H-E stain and immunohistochemistry. Results： With H-E stain,atherosclerotic plaques were found in the radial arteries of 4 uremic patients. The middle layer of the arteries in uremic patients were obviously thickened, and the T/D　(thickness of the wall/external diameter) ratio was significantly higher than those in control group(P<0.01). ox-LDL,CD68,MCP-1, ET-1, PCNA,FN on the vessel wall in uremic patients were much higher than those in control group (P<0.01). Moreover, ox-LDL on the vessel wall was positively related to the expression of other above mentioned substances on the vessel wall (P<0.01). Whereas the expression of eNOS on the vessel wall was lower than control group (P<0.01),and was negatively related to ox-LDL on the vessel wall(P<0.01). Conclusion: ox-LDL is an important factor contributing to uremic vascular remodeling by increasing the migration,adhesion and infiltration of monocyte,the proliferation of vascular smooth muscle cell and dysfunction of endothelia.

Objective:To determine whether ox-LDL (oxdized low-density lipoprotein) is highly deposited on the uremic vessel wall and its influence on the vascular remodeling. Methods: Segments of radial arteries were obtained from 21 uremic subjects during the operation of A-V fistula prior to hemodialysis. Segments of internal thoracic arteries of similar diameter were obtained from patients with benign chest tumors as control.The vascular lesions and ox-LDL, CD68,MCP-1, eNOS,ET-1, PCNA,FN on the vessel wall were determined by means of H-E stain and immunohistochemistry. Results： With H-E stain,atherosclerotic plaques were found in the radial arteries of 4 uremic patients. The middle layer of the arteries in uremic patients were obviously thickened, and the T/D　(thickness of the wall/external diameter) ratio was significantly higher than those in control group(P<0.01). ox-LDL,CD68,MCP-1, ET-1, PCNA,FN on the vessel wall in uremic patients were much higher than those in control group (P<0.01). Moreover, ox-LDL on the vessel wall was positively related to the expression of other above mentioned substances on the vessel wall (P<0.01). Whereas the expression of eNOS on the vessel wall was lower than control group (P<0.01),and was negatively related to ox-LDL on the vessel wall(P<0.01). Conclusion: ox-LDL is an important factor contributing to uremic vascular remodeling by increasing the migration,adhesion and infiltration of monocyte,the proliferation of vascular smooth muscle cell and dysfunction of endothelia.

Though all the marketed drugs of dipeptidyl peptidase IV inhibitors are structurally different, their inherent correlation is worthy of further investigation. Herein we rapidly discovered a novel DPP-IV inhibitor 8g (IC50 = 4.9 nmol.L-1) which exhibits as good activity and selectivity as the market drugs through scaffold hopping and drug splicing strategies based on alogliptin and linagliptin. This study demonstrated that the employment of classic medicinal chemistry strategy to the marketed drugs with specific target is an efficient approach to discover novel bioactive molecules.
Dipeptidyl-Peptidase IV Inhibitors ; chemical synthesis ; chemistry ; Drug Design ; Drug Discovery ; methods ; Humans ; Hypoglycemic Agents ; chemical synthesis ; chemistry ; Linagliptin ; chemical synthesis ; chemistry ; Molecular Structure ; Piperidines ; chemical synthesis ; chemistry ; Structure-Activity Relationship ; Uracil ; analogs & derivatives ; chemical synthesis ; chemistry