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Cell Injection (cell + injection)
Selected AbstractsViscoelastic and Histologic Properties in Scarred Rabbit Vocal Folds After Mesenchymal Stem Cell Injection,THE LARYNGOSCOPE, Issue 7 2006S Hertegård MD Abstract Objective/Hypothesis: The aim of this study was to analyze the short-term viscoelastic and histologic properties of scarred rabbit vocal folds after injection of human mesenchymal stem cells (MSC) as well as the degree of MSC survival. Because MSCs are antiinflammatory and regenerate mesenchymal tissues, can MSC injection reduce vocal fold scarring after injury? Study Design: Twelve vocal folds from 10 New Zealand rabbits were scarred by a localized resection and injected with human MSC or saline. Eight vocal folds were left as controls. Material and Methods: After 4 weeks, 10 larynges were stained for histology and evaluation of the lamina propria thickness. Collagen type I content was analyzed from six rabbits. MSC survival was analyzed by fluorescent in situ hybridization staining from three rabbits. Viscoelasticity for 10 vocal folds was analyzed in a parallel-plate rheometer. Results: The rheometry on fresh-frozen samples showed decreased dynamic viscosity and lower elastic modulus (P < .01) in the scarred samples injected with MSC as compared with the untreated scarred group. Normal controls had lower dynamic viscosity and elastic modulus as compared with the scarred untreated and treated vocal folds (P < .01). Histologic analysis showed a higher content of collagen type 1 in the scarred samples as compared with the normal vocal folds and with the scarred folds treated with MSC. MSCs remained in all samples analyzed. Conclusions: The treated scarred vocal folds showed persistent MSC. Injection of scarred rabbit vocal folds with MSC rendered improved viscoelastic parameters and less signs of scarring expressed as collagen content in comparison to the untreated scarred vocal folds. [source] CURRENT STATUS AND FUTURE PERSPECTIVE OF INTERVENTIONAL ENDOSCOPIC ULTRASOUND IN JAPANDIGESTIVE ENDOSCOPY, Issue 2009Mitsuhiro Kida Vilmann and Grimm made the first reports of endoscopic ultrasound (EUS)-fine needle aspiration (FNA), and since then EUS-FNA has become popular in the clinical fields, especially in Western countries. Furthermore interventional EUS such as pseudocyst drainage, EUS-guided biliary drainage, celiac plexus neurolysis, and dendritic cell injection, etc. have been introduced. We have investigated the current status and future perspectives of interventional EUS in Japan. Standardization of EUS-guided pseudocyst drainage has been achieved, but EUS-guided biliary dranage is still controversial, and EUS-fine needle injection (FNI) including EUS-celiac plexus neurolysis (CPN) and dendritic cell injection have been under investigation. In any case, EUS-FNA seems to be a promising future technique and new applications have to be invented. [source] Relevance of a new rat model of osteoblastic metastases from prostate carcinoma for preclinical studies using zoledronic acidINTERNATIONAL JOURNAL OF CANCER, Issue 4 2008François Lamoureux Abstract Animal models that mimic osteoblastic metastases associated with prostate carcinoma are required to improve the therapeutic options in humans. A new model was then developed and characterized in immunocompetent rats. The bisphosphonate zoledronic acid (ZOL) was tested to validate this model as a therapeutic application. Rat AT6-1 prostate tumor cells were characterized in vitro at the transcriptional (bone and epithelial markers) and functional (induction of mineralized nodules) levels. The bone lesions induced after their direct injection into the femur bone marrow were characterized by radiography, microscanner and histology analyses. ZOL effects were studied in vivo on bone lesion development and in vitro on AT6-1 cell proliferation, apoptosis and cell cycle analysis. Apart from epithelial markers, AT6-1 cells express an osteoblast phenotype as they express osteoblastic markers and are able to induce mineralized nodule formation in vitro. A disorganization of the trabecular bone at the growth zone level was observed in vivo after intraosseous AT6-1 cell injection as well as cortical erosion. The tumor itself is associated with bone formation as revealed by SEM analysis and polarized light microscopy. ZOL prevents the development of such osteoblastic lesions, related to a direct inhibitory effect on tumor cell proliferation independent of caspase 3 activation, but associated with cell cycle arrest. A new rat model of osteoblastic bone metastases was validated in immunocompetent rats and used to show the relevance of using ZOL in such lesions, as this compound shows bifunctional effects on both bone remodelling and tumor cell proliferation. © 2007 Wiley-Liss, Inc. [source] Methylation-Associated Silencing of Death-Associated Protein Kinase Gene in Laryngeal Squamous Cell Cancer,THE LARYNGOSCOPE, Issue 8 2005Wei-Jia Kong MD Abstract Objectives/Hypothesis: Death-associated protein kinase (DAPK) is a Ca2+/calmodulin-regulated Ser/Thr kinase that functions as a positive mediator of programmed cell death. It has been found that DAPK gene is frequently inactivated by its promoter hypermethylation in some cancers and tumor cell lines. However, it is not clear whether promoter hypermethylation of DAPK gene exists in laryngeal squamous cell cancer (LSCC). The aim of this study was to investigate the promoter methylation status of the DAPK gene in LSCC and the effect of 5-Aza-2'-deoxycytidine (5-Aza-CdR), a demethylating agent, on Hep-2 cells, a human laryngeal cancer cell line, and on xenografts of Hep-2. Methods: Methylation-specific polymerase chain reaction (PCR) and reverse-transcription PCR techniques were used to determine the promoter methylation status and mRNA expression of DAPK gene in LSCC. Furthermore, Hep-2 cells in vitro and in vivo were treated by 5-Aza-CdR to explore the effect of demethylating agents on DAPK mRNA expression and tumor growth. Results: Hypermethylation of DAPK gene promoter was found in 39 (67.2%) of 58 LSCC samples. There was no significant difference in the promoter hypermethylation rate among the samples of different histologic grades or samples from patients with different T stages. However, there was significant difference in methylation status of DAPK gene between the samples from patients in N0 stages and those from patients in N1 stages. No promoter hypermethylation of DAPK gene was found in any of the five normal laryngeal tissue samples. DAPK mRNA expression was not detected in tumor specimens with promoter hypermethylation. On the contrary, DAPK mRNA expression was observed in the unmethylated tumor specimens, specimens from tissues adjacent to the tumor, and normal laryngeal tissues samples. Promoter hypermethylation of DAPK gene was found, and no DAPK mRNA expression was detected in Hep-2 cells. DAPK mRNA expression in Hep-2 cells and xenografts could be restored by treating cells and xenografts with 5-Aza-CdR. The tumors' xenografts, induced by way of Hep-2 cell injection in nude mice treated with 5-Aza-CdR, were obviously smaller than those in nude mice treated with phosphate-buffered saline. Conclusions: Abnormal loss of DAPK expression could be associated with aberrant promoter region methylation in the LSCC. 5-Aza-CdR may slow the growth of Hep-2 cells in vitro and in vivo by reactivating tumor suppressor gene DAPK silenced by de novo methylation. [source] Evaluation of the effect of autologous mesenchymal stem cell injection in a large-animal model of bilateral kidney ischaemia reperfusion injuryCELL PROLIFERATION, Issue 3 2009L. Behr Objectives: Adult mesenchymal stem cells (MSC) have been proven to be of benefit to the kidney in different experimental models of renal injuries. All studies have been performed in valuable rodent models, but the relevance of these results to large mammals and ultimately, to humans remains unknown. Therefore, the aim of this study was to investigate the effect of MSC transplantation in an alternative ovine large-animal model of bilateral kidney ischaemia reperfusion injury. Material and methods: Sheep were divided into three groups: one sham-operated group and two groups submitted to renal bilateral ischaemia for 60 min. Animals with ischaemia reperfusion injury were treated with injection of autologous MSCs or with vehicle medium. Results: The model sheep presented with renal histological manefestations that closely resembled lesions seen in patients. Transplanted MSCs were found in glomeruli but not in tubules and did not express glomerular cell markers (podocin, von Willebrand factor), but functional evaluation showed no beneficial effect of MSC infusion. Morphological and molecular analyses corroborated the functional results. MSCs did not repair kidney parenchyma and failed to modulate cell death and proliferation or cytokine release (tumour necrosis factor-alpha, vascular endothelial growth factor alpha (VEGF-,), Bcl-2, caspase). Conclusion: In this unique autologous large-animal model, MSCs did not exhibit reparative or paracrine protective properties. [source] | ||||||||||