In Vitro and Ectopic In Vivo Studies toward the Utilization of Rapidly Isolated Human Nasal Chondrocytes for Single-Stage Arthroscopic Cartilage Regeneration Therapy.

Nasal chondrocytes (NCs) have a higher and more reproducible chondrogenic capacity than articular chondrocytes, and the engineered cartilage tissue they generate in vitro has been demonstrated to be safe in clinical applications. Here, we aimed at determining the feasibility for a single-stage application of NCs for cartilage regeneration under minimally invasive settings. In particular, we assessed whether NCs isolated using a short collagenase digestion protocol retain their potential to proliferate and chondro-differentiate within an injectable, swiftly cross-linked and matrix-metalloproteinase (MMP)-degradable polyethylene glycol (PEG) gel enriched with human platelet lysate (hPL). NC-hPL-PEG gels were additionally tested for their capacity to generate cartilage tissue in vivo and to integrate into cartilage/bone compartments of human osteochondral plugs upon ectopic subcutaneous implantation into nude mice. NCs isolated with a rapid protocol and embedded in PEG gels with hPL at low cell density were capable of efficiently proliferating and of generating tissue rich in glycosaminoglycans and collagen II. NC-hPL-PEG gels developed into hyaline-like cartilage tissues upon ectopic in vivo implantation and integrated with surrounding native cartilage and bone tissues. The delivery of NCs in PEG gels containing hPL is a feasible strategy for cartilage repair and now requires further validation in orthotopic in vivo models.

Interaction between extracellular cancer matrix and stromal breast cells.

INTRODUCTION: Stromal-epithelial interactions are fundamental for normal organ development and there is a multitude of evidence that the different components of the microenvironment are also necessary for the maintenance and promotion of the "tumor organ". Deregulated tumor associated extracellular matrix (tECM) is a hallmark of cancer, causing an alteration in the amount and composition of the different components (i.e. proteins, proteoglycans, glycoproteins and polysaccharids) of the ECM. As epithelial-stromal interactions are reciprocal, it is possible that tECM itself is able to initiate tumor development. We therefore established a mouse model to examine the influence of tECM of murine breast cancer on developing breast tissue in mice. MATERIALS AND METHODS: Breast cancer was established in 5 BALB/c mice by subcutaneous injection of 1×106 4T1 cells in 100µl PBS into the left mammary fat pad. The mammary fat pad including the primary tumor was excised after two weeks, decellularised and labelled as tumor extracellular matrix (tECM). Tumor ECM of 4T1 tumors was implanted into the 4th inguinal mammary fat pad of BALB/c mice (n = 5) aged 5 days. After 12 weeks the fourth mammary fat pad including the primary tumor was excised. Tissue was used for paraffin embedding and mouse breast cancer PCR array. Murine breast cancer tissue (BCT) and normal murine breast tissue (BT) served as control. RESULTS: Gene array analysis of 84 breast cancer-specific transcripts revealed that the mammary gland cells which were exposed to tumor ECM (tECM-BT) showed a similarly high overexpression for 22 genes as apparent for breast cancer tissue (BCT). The corresponding scatter plot showed a high agreement in the expression of the examined genes between the mammary gland cells which were exposed to tumor ECM and the breast cancer tissue. DISCUSSION: Our results clearly demonstrate that the tECM is able to shift the gene expression pattern of murine mammary epithelial cells towards that of carcinoma, indicating a role in breast cancer initiation. These data underlines that the acellular component of the tumor (ECM) can lead to a transformation of mammary gland tissue cells. These data show for the first time that the interaction of normal breast tissue cells with tumor ECM leads to an exchange of information and a consecutive overexpression of tumor-specific genes.

Intra-individual comparison of human nasal chondrocytes and debrided knee chondrocytes: Relevance for engineering autologous cartilage grafts.

OBJECTIVE: Implantation of autologous chondrocytes for cartilage repair requires harvesting of undamaged cartilage, implying an additional joint arthroscopy surgery and further damage to the articular surface. As alternative possible cell sources, in this study we assessed the proliferation and chondrogenic capacity of debrided Knee Chondrocytes (dKC) and Nasal Chondrocytes (NC) collected from the same patients. METHODS: Matched NC and dKC pairs from 13 patients enrolled in two clinical studies (NCT01605201 and NCT026739059) were expanded in monolayer and then chondro-differentiated in 3D collagenous scaffolds in medium with or without Transforming Growth Factor beta 1 (TGFß1). Cell proliferation and amount of cartilage matrix production by these two cell types were assessed. RESULTS: dKC exhibited an inferior proliferation rate than NC, and a lower capacity to chondro-differentiate. Resulting dKC-grafts contained lower amounts of cartilage specific matrix components glycosaminoglycans and type II collagen. The cartilage forming capacity of dKC did not significantly correlate with specific clinical parameters and was only partially improved by medium supplemention with TGFß1. CONCLUSIONS: dKC exhibit a reproducibly poor capacity to engineer cartilage grafts. Our in vitro data suggest that NC would be a better suitable cell source for the generation of autologous cartilage grafts.

Posterior pelvic ring fractures: Intraoperative 3D-CT guided navigation for accurate positioning of sacro-iliac screws.

INTRODUCTION: Posterior pelvic ring fractures frequently pose a problem of stability with an elevated risk of complications. The traditional method of percutaneous sacroiliac (SI) stabilization with the use of fluoroscopic image amplifiers demands a high degree of experience and has an elevated risk of screws' malpositioning. HYPOTHESIS: Intraoperative 3D-CT scan coupled with a navigation system (O-Arm©) can allow screw fixation accuracy while limiting the risk of complications for the treatment of posterior pelvic ring fractures. MATERIAL AND METHODS: Patients with posterior pelvic ring fractures stabilized with percutaneous SI screws through O-Arm© navigation from August 2008 to December 2017 were analyzed. A modified Gras classification was used to determine screws' positioning under CT visualization, and intraoperative and early postoperative complications were documented. RESULTS: Among the 21 patients evaluated, 14 men and 7 women with a mean age of 57.8 years (range 25-91), receiving 39 screws, the rate of misplacement was low: 82% grade I, 15.4% grade II, and only 2.6% grade III. Only one patient underwent revision surgery, not because of misplacement but rather for a secondary implant loosening. No complications occurred in this series. DISCUSSION: This study documented a large series of patients treated for pelvic ring fractures using the intraoperative 3D-CT O-Arm© guided navigation. This surgical approach provided a precise and safe SI screw positioning with no complications. LEVEL OF EVIDENCE: IV, Retrospective study.

[Early results of topotecan therapy in patients with recurrent ovarian cancer]. / Kiújult petefészekrák topotecankezelésével szerzett korai tapasztalatok.

INTRODUCTION: Topotecan inhibits the topoisomerase-I enzyme resulting its stabilisation on the DNA and the suspension of replication and transcription. AIMS: The authors summarized their first experience on second-line topotecan treatment in a prospective non-randomized study. METHOD: Topotecan was given for recurrent epithelial ovarian cancer in the dose of 1.5 mg/m2/d for 5 days repeated in every 3 weeks in a 30-minute infusion intravenously. RESULTS: Twenty five recurrent ovarian cancer patients were treated between March, 1999 and March, 2001. Complete and partial response rates were found 12% and 12%, respectively. Stable disease was observed in 48% of patients for 4-8 courses, then progression continued. In these 3 groups of patients the median progression free interval was shown as 12 weeks. CONCLUSION: When comparing to previous chemotherapies, topotecan treatment failed to show a definitive improvement in the outcome of recurrent ovarian cancer.