Sodium halide solid state electrolyte of Na3YBr6 with low activation energy.

Halide solid-state electrolytes (SSEs) are considered promising candidates for practical applications in all-solid-state batteries (ASSBs), due to their outstanding high voltage stability and compatibility with electrode materials. However, Na+ halide SSEs suffer from low ionic conductivity and high activation energy, which limit their applications in sodium all-solid-state batteries. Here, sodium yttrium bromide solid-state electrolytes (Na3YBr6) with a low activation energy of 0.15 eV is prepared via solid state reaction. Structure characterization using X-ray diffraction reveals a monoclinic structure (P21/c) of Na3YBr6. First principle calculations reveal that the low migration activation energy comes from the larger size and vibration of Br- anions, both of which expand the Na+ ion migration channel and reduce its activation energy. The electrochemical window of Na3YBr6 is determined to be 1.43 to 3.35 V vs. Na/Na+, which is slightly narrower than chlorides. This work indicates bromides are a good catholyte candidate for sodium all solid-state batteries, due to their low ion migration activation energy and relatively high oxidation stability.

The RING Domain of Rice HEI10 is Essential for Male, But Not Female Fertility.

HEI10 is a conserved E3 ubiquitin ligase involved in crossover formation during meiosis, and is thus essential for both male and female gamete development. Here, we have discovered a novel allele of HEI10 in rice that produces a truncated HEI10 protein missing its N-terminal RING domain, namely sh1 (shorter hei10 1). Unlike previously reported hei10 null alleles that are completely sterile, sh1 exhibits complete male sterility but retains partial female fertility. The causative sh1 mutation is a 76 kb inversion between OsFYVE4 and HEI10, which breaks the integrity of both genes. Allelic tests and complementation assays revealed that the gamete developmental defects of sh1 were caused by disruption of HEI10. Further studies demonstrated that short HEI10 can correctly localise to the nucleus, where it could interact with other proteins that direct meiosis; expressing short HEI10 in hei10 null lines partially restores female fertility. Our data reveal an intriguing mutant allele of HEI10 with differential effects on male and female fertility, providing a new tool to explore similarities and differences between male and female meiosis.

Roles of MT-ND1 in Cancer.

The energy shift toward glycolysis is one of the hallmarks of cancer. Complex I is a vital enzyme complex necessary for oxidative phosphorylation. The mitochondrially encoded NADH: ubiquinone oxidoreductase core subunit 1 (MT-ND1) is the largest subunit coded by mitochondria of complex I. The present study summarizes the structure and biological function of MT-ND1. From databases and literature, the expressions and mutations of MT-ND1 in a variety of cancers have been reviewed. MT-ND1 may be a biomarker for cancer diagnosis and prognosis. It is also a potential target for cancer therapy.

LncRNA SPRY4­IT1 promotes progression of osteosarcoma by regulating ZEB1 and ZEB2 expression through sponging of miR­101 activity.

Long non­coding (lnc)RNA sprouty receptor tyrosine kinase signalling antagonist 4­intronic transcript 1 (SPRY4­IT1) has been demonstrated to serve a critical role in the tumorigenesis of osteosarcoma (OS); however, the specific underlying mechanism remains unclear. The aim of the present study was to examine the interactions between SPRY4­IT1 and its downstream effectors, to determine if any of the interactions contributed to SPRY4­IT1­mediated proliferation, migration and invasion in cancer cells. A signalling cascade which involved SPRY4­IT1, miR­101 and zinc finger E­box­binding homeoboxes (ZEBs) was examined in the present study. Intracellular SPRY4­IT1 and miR­101 expression levels were altered through transfection to assess their effect on proliferation, cell cycle progression, survival, migration and invasion. A dual­luciferase assay was utilized to determine the association between SPRY4­IT1/miR­101 and ZEBs/miR­101 and nude mouse xenograft experiments were performed to determine the effect of SPRY4­IT1 in vivo. The results indicated that the SPRY4­IT1 levels were negatively associated with miR­101 expression levels in OS cells, an association which was not observed in the normal osteoblast cells. SPRY4­IT1 knockdown or miR­101 overexpression reduced proliferation, cell cycle progression, survival, migration and invasion of MG­63 and U2OS cells. SPRY4­IT1 knockdown was accompanied by increased expression of miR­101 and E­cadherin levels, as well as decreased expression levels of ZEB1/2 and other epithelial­mesenchymal transition­associated proteins. Simultaneous knockdown of SPRY4­IT1 and inhibition of miR­101 partially reversed the anti­tumour effects of SPRY4­IT1 inhibition in vitro. Consistent with these findings, short hairpin RNA targeting SPRY4­IT1 also hindered xenograft tumour growth and altered the levels of miR­101, ZEB1/2 and E­cadherin in vivo. Dual­luciferase reporter assays demonstrated that SPRY4­IT1 may have regulated the expression of ZEB1 and ZEB2 by sponging miR­101. In conclusion, SPRY4­IT1 inhibition increased miR­101 levels, resulting in downregulation of ZEB1/2 expression and thus exerting anti­tumour effects in OS.

[Case-control study on self-setting calcium phosphate cement and allograft for Sanders II-IV fractures of calcaneus].

OBJECTIVE: To compare clinical results of Sanders II-IV fractures of calcaneus treated by self-setting calcium phosphate cement and allograft with locking reconstruction bone plate internal fixation. METHODS: From March 2012 to December 2015, 48 patients with Sanders II-IV fractures of calcaneus were treated by open reduction and internal fixation through L-shape incision, bone grafting were performed on reserved bone defect of calcaneal fracture. The patients were divided into self-setting calcium phosphate cement and allograft group according to different materials. Twenty-eight patients in self-setting calcium phosphate cement group, including 23 males and 5 females aged from 22 to 52 years old with an average of (34.46±7.33) years old; 8 cases were type II, 11 cases were type III and 7 cases were type IV according to Sanders classification. Twenty patients in allograft group, including 17 males and 3 females aged from 24 to 55 years old with an average of(36.40±7.93) years old; 6 cases were type II, 7 cases were type III and 9 cases were type IV according to Sanders classification. Postoperative wound complications, Böhler angle before and after operation and 12 months, Maryland functional score were evaluated. RESULTS: All patients obtained bone union, and were followed up from 12 to 42 months with an average of 25 months. There were no statistical significance in Böhler angle and Manyland score before and after operation and 12 months between two groups. Five patients occurred wound complications in allograft group and 2 cases occurred wound complications in self-setting calcium phosphate cement and allograft group. CONCLUSIONS: Both of open reduction bone grafting and reconstructive plate internal fixation have good effective results for calcaneal fracture. Compared with allograft, self-setting calcium phosphate cement, which has no rejection response and less complications, has equal effects for calcaneal fracture and deserves to be popularized.

Case-control study on self-setting calcium phosphate cement and allograft for Sanders II-IV fractures of calcaneus / 中国骨伤

<p><b>OBJECTIVE</b>To compare clinical results of Sanders II-IV fractures of calcaneus treated by self-setting calcium phosphate cement and allograft with locking reconstruction bone plate internal fixation.</p><p><b>METHODS</b>From March 2012 to December 2015, 48 patients with Sanders II-IV fractures of calcaneus were treated by open reduction and internal fixation through L-shape incision, bone grafting were performed on reserved bone defect of calcaneal fracture. The patients were divided into self-setting calcium phosphate cement and allograft group according to different materials. Twenty-eight patients in self-setting calcium phosphate cement group, including 23 males and 5 females aged from 22 to 52 years old with an average of (34.46±7.33) years old; 8 cases were type II, 11 cases were type III and 7 cases were type IV according to Sanders classification. Twenty patients in allograft group, including 17 males and 3 females aged from 24 to 55 years old with an average of(36.40±7.93) years old; 6 cases were type II, 7 cases were type III and 9 cases were type IV according to Sanders classification. Postoperative wound complications, Böhler angle before and after operation and 12 months, Maryland functional score were evaluated.</p><p><b>RESULTS</b>All patients obtained bone union, and were followed up from 12 to 42 months with an average of 25 months. There were no statistical significance in Böhler angle and Manyland score before and after operation and 12 months between two groups. Five patients occurred wound complications in allograft group and 2 cases occurred wound complications in self-setting calcium phosphate cement and allograft group.</p><p><b>CONCLUSIONS</b>Both of open reduction bone grafting and reconstructive plate internal fixation have good effective results for calcaneal fracture. Compared with allograft, self-setting calcium phosphate cement, which has no rejection response and less complications, has equal effects for calcaneal fracture and deserves to be popularized.</p>

[Surgical revision of lumbar vertebrae using transforaminal endoscopic spine system].

OBJECTIVE: To explore the clinical effects of transforaminal endoscopic spine system in surgical revision of lumbar vertebrae. METHODS: From January 2012 to October 2013,14 patients who needed reoperations of lumbar vertebrae were treated using transforaminal endoscopic spine system (TESSYS). There were 8 males and 6 males, aged from 27 to 84 years old with an average of (50.4 ± 18.9) years. Visual analogue scale (VAS) and Japanese Orthopaedic Association Scores (JOA) were compared before and after surgical revision. Macnab standard was used to assess the clinical effect. RESULTS: All the patients were followed up from 6 to 27 months with the mean of 18 months. Preoperative VAS score was 6.79 ± 1.31, and in a week,3 months and 6 months after operation were 2.50 ± 1.29, 2.21 ± 1.53, 1.64 ± 1.08, respectively, which were all much lower (P < 0.01) than preoperative score. Preoperative JOA score was 12.43 ± 1.95, and the above corresponding postoperative JOA scores were 21.50 ± 3.78, 21.93 ± 4.55, 23.36 ± 4.33, respectively, which were all much higher than preoperative score (P < 0.01). According to the modified Macnab criteria, 5 patients got an excellent results, 7 good, 1 fair and 1 poor. The nerve root injury of L5 occurred in 1 case during paracentesis and no other complications were found. CONCLUSION: Selecting the appropriate indications using TESSYS in surgical revision of lumbar vertebrae can successfully avoid the operation scar, reduce the surgical complications and obtain satisfactory clinical outcomes.

[Analysis of posterior lumbar interbody fusion (PLIF) in treating lumbar degenerative disease in elderly patients].

OBJECTIVE: To explore the clinical effects of PLIF surgery for elderly patients with lumbar degenerative disease. METHODS: From March 2010 to May 2013, 28 patients with lumbar degenerative disease, aged more than 80 years were treated with PLIF surgery. There were 10 males and 18 females, aged from 80 to 93 years old with an average of (85.44±3.66) years. Course of disease was from 3 to 20 years. The operation time, intra-operative blood loss, operation complications were recorded and JOA scores and Macnab criteria were used to evaluate the clinical outcomes. RESULTS: All patients were followed up from 12 to 40 months with an average of 26.5 months. The average operation time was (150.00±26.42) min and the average intra-operative blood loss was (373.33±99.88) ml. The pre-operative JOA score was 12.30±2.43, and the corresponding postoperative JOA score at the final follow-up was 24.81±2.09 which was much higher than the preoperative one (P<0.01). According to the modified Macnab criteria to evaluate at the final follow-up, 16 patients got an excellent result, 10 good, 2 fair. In the weeks postoperatively, injuries of nerve root happened in 3 cases, superficial wound infection with delayed healing in 3 cases, and tear of the dural sac accompanied with cerebrospinal fluid leakage in 1 case. After long term follow-up, adjacent segment degeneration and the corresponding spinal canal stenosis occurred in 1 case at 34 months after operation. All cases got successful fusion without any displacement of internal fixation and pseudoarthrosis formation. CONCLUSION: With proper cases, fully preoperative preparation, perfect intra-operative manipulation and active treatment after operation, even advanced ages older than 80 years with lumbar degenerative disease could get satisfactory outcomes after PLIF surgery.

Epithelial-to-mesenchymal transition predicts cyclosporine nephrotoxicity in renal transplant recipients.

Maintenance immunosuppression with cyclosporine A (CsA) can cause nephrotoxicity in renal transplant recipients. Identifying patients at increased risk for CsA nephrotoxicity may allow interventions to prolong graft survival. Here, we studied the effect of early CsA withdrawal or maintenance among 96 kidney recipients at risk for interstitial fibrosis and tubular atrophy (IF/TA) on the basis of tubular expression of vimentin and ß-catenin in a protocol biopsy performed 3 months after transplant. In this retrospective analysis of biopsies collected during a randomized trial of early withdrawal of CsA or mycophenolate mofetil, the semiquantitative score of early phenotypic changes suggestive of epithelial-to-mesenchymal transition (EMT) progressed with time among those maintained on a CsA-containing regimen. EMT-positive grafts displayed a significantly higher IF/TA score and greater progression of the IF/TA score at 12 months (P=0.001 and 0.008, respectively). EMT-positive grafts exposed to CsA also had a greater decrease in estimated GFR compared with EMT-negative grafts exposed to CsA and EMT-positive grafts withdrawn from CsA exposure. Multivariable analysis revealed that the presence of EMT was an independent risk factor for a 10% decline in graft function up to 4 years posttransplant (odds ratio 4.49; 95% confidence interval 1.02 to 19.9). Collectively, these data demonstrate that changes consistent with EMT are strong prognostic biomarkers in renal transplant recipients exposed to CsA.

[Effects of serum containing Fructus Cnidii and Psoralea corylifolia on highly metastatic human breast cancer cell line MDA-MB-231BO and bone marrow stromal cell line ST-2].

OBJECTIVE: To explore the effects of different proportions of Fructus Cnidii (Shechuangzi) and Psoralea corylifolia (Buguzhi) on highly metastatic human breast cancer cell line MDA-MB-231BO and bone marrow stromal cell line ST-2 in vitro. METHODS: Thirty-six female SD rats were randomly divided into 6 groups to prepare the drug-medicated sera by administering with different proportions of Fructus Cnidii and Psoralea corylifolia, including 4:0 group, 3:1 group, 1:1 group, 1:3 group, 0:4 group and control group. MDA-MB-231BO cells and ST-2 cells were cultured in Dulbecco's modified Eagle's medium containing drug-medicated serum. Inhibition rates of MDA-MB-231BO cells and ST-2 cells were measured by methyl thiazolyl tetrazolium (MTT) method; migration ability of MDA-MB-231BO cells was tested by a cell migration experiment; alkaline phosphatase activity (ALP) of ST-2 cells was measured by using 4-nitrophenyl phosphate disodium salt, and mineralized nodule formation of ST-2 cells was measured by alizarin red staining. RESULTS: Sera contaning different proportions of Fructus Cnidii and Psoralea corylifolia inhibited the migration activity of MDA-MB-231BO cells as compared with the blank serum, and serum contaning Fructus Cnidii and Psoralea Corylifolia at proportion of 1:1 had the best function (P<0.01). Fructus Cnidii and Psoralea corylifolia at ratio of 1:1 also enhanced the ALP activity of ST2 cells (P<0.05) and increased the number of mineralized nodules of ST2 cells (P<0.01). CONCLUSION: Kidney-warming recipe of Fructus Cnidii and Psoralea corylifolia can inhibit proliferation and migration of MDA-MB-231BO cells and increase the activity of ST-2 cells.

[Interstitial fibrosis in renal grafts: On the way to a better detection]. / Fibrose interstitielle du greffon rénal : vers un meilleur dépistage.

In renal grafts, the progression of interstitial fibrosis and tubular atrophy (IF/TA) is exponential during the first months post-transplant. Consequently, roughly 40% of the cadaveric grafts will function less than ten years. There is, however, no specific strategy to halt fibrogenesis, i.e. the progression of fibrosis with time, in kidney recipients. Epithelial to mesenchymal transition (EMT) is a biological process used to disperse cells during embryogenesis. In the setting of injury, it is also a mechanism to escape cellular death. The last five years, several studies demonstrated that EMT does occur in tubular epithelial cells, which have been shown to loose the expression of epithelial markers, and acquire the expression of mesenchymal proteins, like vimentin. The aim of this review is triple: 1) discuss the connections between EMT and the context of transplantation; 2) explain how EMT markers may be useful in clinical practice, as promising surrogate markers for fibrogenesis; 3) discuss some therapeutic perspectives.

[Additional screws fixation on fractured vertebrae versus only short-segment posterior instrumentation for thoracolumbar A3 fracture without neurologic deficit].

OBJECTIVE: To compare the clinical results of additional screws fixation on fractured vertebrae versus only short-segment posterior transpedicular instrumentation for A3 thoracolumbar fracture without neurologic deficit. METHODS: Clinical data of 52 cases of thoracolumbar burst fracture without neurologic deficit were retrospectively analyzed. All patients were divided into 2 groups due to different instrumentation and all fractures were classified as type A3 according to AO Classification.From January 2005 to December 2006, 23 cases in group A were treated by short-segment posterior instrumentation combined with additional screws fixation on fractured vertebrae. There were 18 male and 5 female with a mean age of (35.3+/-8.3) years. The fracture segment included 1 in T11, 9 in T12, 11 in L1 and 2 in L2. From January 1999 to December 2004, 29 cases in group B were treated only by conventional short-segment posterior transpedicular instrumentation. There were 20 male and 9 female with a mean age of (37.3+/-6.8) years. The fracture segment included 1 in T11, 7 in T12, 20 in L1 and 1 in L2. The clinical effect and radiographic measurements were respectively compared preoperatively, immediate and 2 years postoperatively. RESULTS: All patients were followed up and the mean follow-up time was (37.4+/-10.9) months (from 24 to 48 months). There was no statistic difference of mean JOA and VAS score between 2 groups preoperatively, immediate and 2 years postoperatively (P>0.05). The average immediate postoperative correction of Cobb's angle was 13.7 degrees+/-7.7 degrees in group A, which was statistically significantly higher than that of 8.8 degrees+/-5.0 degrees in group B (P<0.01). The mean kyphosis correction loss of 2.9 degrees+/-1.5 degrees in group A was statistically significantly lower than that of 5.0 degrees+/-2.9 degrees in group B 2 years postoperatively (P<0.01). The average restoration of anterior height of fractured vertebral body immediate postoperatively was (29.4+/-6.0)% and (21.7+/-6.9)% respectively. The mean correction loss of anterior height 2 years postoperatively was (3.1+/-0.8)% and (6.6+/-3.0)% respectively. The average restoration of posterior height of fractured vertebral body immediate postoperatively was (8.5+/-3.2)% and (6.1+/-1.8)% respectively. The mean correction loss of posterior height 2 years postoperatively was (2.0+/-0.8)% and (3.4+/-1.0)% respectively. There were significant differences in average restoration of anterior/posterior height immediate postoperatively and correction loss of anterior/posterior height 2 years postoperatively between the 2 groups (P<0.01). According to fracture fragments protruded into the spinal canal on immediate postoperative CT image, there were complete reduction in 11 cases (47.8%) and partial reduction in 12 cases (52.2%) in group A, which was statistically significantly better than those in group B (P<0.01). There was no severe neurologic complications and no other complications related to additional screws fixation postoperatively. Pedicle screw breakage occurred in 2 cases in group B and none in group A. CONCLUSIONS: Better initial kyphosis correction and less loss of correction 2 years after operation can be obtained by using additional screws fixation on fractured vertebra for thoracolumbar A3 fracture without neurologic deficit.

Concurrent arthroscopic bicruciate ligament reconstruction using Achilles tendon-bone allografts: experience with 15 cases.

OBJECTIVE: To evaluate the clinical outcome of arthroscopically assisted combined anterior and posterior cruciate ligament (ACL/PCL) reconstructions using Achilles tendon-bone allografts. METHODS: Associated meniscus injuries were treated according to established methods prior to ligament reconstructions during arthroscopic surgery. Thirty Achilles tendon-bone allografts were used to reconstruct torn ACL and PCL in 15 knees. At postoperative follow-up, all knees were graded using the modified IKDC and the Lysholm scoring systems just as done preoperatively. RESULTS: were analyzed compared with the contralateral healthy knees. Results: Eleven men and 4 women with a minimum of 3-year follow-up (mean 38 months) were included in the study. Preoperatively, the group ratings by the modified IKDC standards were all severely abnormal. Twelve bicruciate reconstructions were performed in subacute or chronic stage (larger than 3-8 weeks), 3 for acute ligamentous deficiencies (less than or equal to 3 weeks). The noticeable early complication was transitory local fever combined with joint effusion in one case. At postoperative follow-up, 9 knees were normal, 5 nearly normal and 1 abnormal. On Lysholm score the difference was statistically significant (t- test, P less than 0.001) before and after operation. CONCLUSIONS: Achilles tendon-bone allograft offers an alternative for simultaneous arthroscopic ACL/PCL reconstructions. However, further investigation is needed to eradicate its potential immunogenicity for better use.

Two hybrid compaction algorithms for the layout optimization problem.

In this paper we present two new algorithms for the layout optimization problem: this concerns the placement of circular, weighted objects inside a circular container, the two objectives being to minimize imbalance of mass and to minimize the radius of the container. This problem carries real practical significance in industrial applications (such as the design of satellites), as well as being of significant theoretical interest. We present two nature-inspired algorithms for this problem, the first based on simulated annealing, and the second on particle swarm optimization. We compare our algorithms with the existing best-known algorithm, and show that our approaches out-perform it in terms of both solution quality and execution time.

Development and potential of a biomimetic chitosan/type II collagen scaffold for cartilage tissue engineering.

BACKGROUND: Damaged articular cartilage has very limited capacity for spontaneous healing. Tissue engineering provides a new hope for functional cartilage repair. Creation of an appropriate cell carrier is one of the critical steps for successful tissue engineering. With the supposition that a biomimetic construct might promise to generate better effects, we developed a novel composite scaffold and investigated its potential for cartilage tissue engineering. METHODS: Chitosan of 88% deacetylation was prepared via a modified base reaction procedure. A freeze-drying process was employed to fabricate a three-dimensional composite scaffold consisting of chitosan and type II collagen. The scaffold was treated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. Ultrastructure and tensile strength of the matrix were carried out to assess its physico-chemical properties. After subcutaneous implantation in rabbits, its in vivo biocompatibility and degradability of the scaffold were determined. Its capacity to sustain chondrocyte growth and biosynthesis was evaluated through cell-scaffold co-culture in vitro. RESULTS: The fabricated composite matrix was porous and sponge-like with interconnected pores measuring from 100-250 microm in diameter. After cross-linking, the scaffold displayed enhanced tensile strength. Subcutaneous implantation results indicated the composite matrix was biocompatible and biodegradable. In intro cell-scaffold culture showed the scaffold sustained chondrocyte proliferation and differentiation, and maintained the spheric chondrocytic phenotype. As indicated by immunohistochemical staining, the chondrocytes synthesized type II collagen. CONCLUSIONS: Chitosan and type II collagen can be well blended and developed into a porous 3-D biomimetic matrix. Results of physico-chemical and biological tests suggest the composite matrix satisfies the constraints specified for a tissue-engineered construct and may be used as a chondrocyte carrier for cartilage tissue engineering.

[Comparative study of vertebral body stress distribution following insertion of artificial lumbar intervertebral disc].

OBJECTIVE: To study vertebral body stress distribution of normal disc, post-Diskectomy and artificial disk respectively by 3-D finite element methods, and to explore artificial intervertebral disk insertion impact on stress distribution of vertebral body. METHODS: Models of normal disk, post-Diskectomy, artificial disk and L(4 - 5) motion segment were established by using finite element software MSC. MARK, then vertebral body stress was analyzed through model of L(4 - 5) motion segment respectively. RESULTS: The vertebral body's stress was the smallest after insertion of artificial intervertebral disk (AID), and its stress distributed equally. But the stress under post-discectomy was bigger than the normal disc's in all the motion state. On the other hand, the stress distribution state of the post-discectomy changed while the spine were in different motion state, during the spine flexion, the stress in the anterior of vertebral body was the biggest; While extension, in the posterior and in right flexion state, the biggest stress was in the right. While vertical compression and rotation, the stress distributed equally. CONCLUSION: The results illustrate that the vertebral body's stress is the smallest after insertion of AID in 3 groups of all motion state, and its stress distributes equally. But the level of vertebral body stress increases after discectomy comparing with the normal group. In generally, it is much more reasonable that the disc is reconstructed with AID because of the biomechanical effect on vertebral body made by AID insertion.

Morphological insights into the origin of glomerular endothelial and mesangial cells and their precursors.

Glomerular endothelial and mesangial cells may originate from the metanephric mesenchyme. We used the MAb Thy1.1, a mesangial cell marker in the adult rat kidney, and rat endothelial cell markers MAb RECA-1, MAb PECAM-1 (CD31), and MAb Flk-1 as potential markers to characterize the spatial and temporal distribution of mesangial and endothelial cell precursors during nephrogenesis in the rat. At early stages of glomerulogenesis, RECA-1- and Thy1.1-positive cells were detected in the metanephric blastema at 14 days post conception (dpc) embryos and 15 dpc, respectively, with Thy1.1 expression in cells surrounding the ureteric bud. At 17 and 18 dpc, both RECA-1- and Thy1.1-positive cells were found in the cleft of the S-shaped bodies and in the capillary loops of maturing glomeruli. Double staining for BrdU, a marker of proliferation, and for RECA-1 or BrdU and Thy1.1 also localize in the cleft of S-shaped bodies and in glomerular capillary loops at later stages of development. PDGFRbeta co-localizes in cells expressing endothelial or mesangial markers. The data suggest that endothelial and mesangial cell precursors share common markers during the course of glomerulogenesis and that full differentiation of these cells occurs at late stages of glomerular maturation. Thy1.1- and RECA-1-positive cells may be derived from the metanephric blastemal cells at early stages of kidney development. A subpopulation of these Thy1.1- or RECA-1-positive cells may be precursors that can migrate into the cleft of comma and S-shaped bodies and proliferate in situ to form glomerular capillary tufts.