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Biomedical subjects

C Doillon

Publications and source records attributed to C Doillon.

13 recordsLinked to original sources
PubMed2000

Three-dimensional type I collagen co-culture systems for the study of cell-cell interactions and treatment response in bone metastases.

The available monolayer culture systems for the study of bone metastases constitute a suboptimal simulation of the in vivo pathophysiology of bone metastases, and therefore, do not provide sufficient information to assess the morphologic evidence of bone reaction to cancer cells, the nature of cell-specific mediators of osteolysis and osteoplasia and the response to treatment. Therefore, we have developed a three-dimensional (3-D) type I collagen gel system that allows co-culture of human osteoblasts (MG-63) with cancer cells, such as MCF-7, MDA-MB-231 or ZR-75 breast cancer cells, PC-3 prostate cancer, KLE endometrial cancer cells and Calu-1 lung cancer cells. We used type I collagen purified from rat tail tendons and the 3-D system was prepared by mixing MG-63 cells with type I collagen in 24-well plates. The 3-D system was inoculated with cancer cells and processed with standard cell culture procedures. After 1 week of culture, the matrix gel was fixed with formalin and embedded in paraffin. Serial sections were stained with trichrome Masson stain and modified Masson-Goldner stain, as well as analyzed by in situ hybridization, immunohistochemistry and the TUNEL technique for semi-quantitative detection of apoptotic cell death, assessing the response to adriamycin therapy. The inoculation of PC-3 cells in this collagen matrix produced a blastic reaction, documented by an increased number of MG-63 cells and increased density of type I collagen. The human KLE cells and inoculation of cell-free media produced no reaction, while ZR-75, MCF-7 and Calu-1 cells produced local degradation of the collagen matrix. In situ hybridization revealed the expression of Insulin-like growth factor 1 (IGF-1) and urokinase-type plasminogen activator (uPA) mRNA, while immunohistochemistry detected differential expression of uPA and cathepsin D. Adriamycin induced apoptotic cell death in prostate cancer cells and estrogen receptor negative (ER-) MDA-MB-231 breast cancer cells, while adriamycin did not induce apoptosis but cytostasis in ER+ MCF-7 cells. The adriamycin-induced apoptosis was inhibited by co-culture with osteoblast-like cells (MG-63). We conclude that this 3-D culture system is a useful in vitro model allowing the analysis of local mediators of osteolytic and osteoblastic reactions to bone metastases and treatment response.

Journal Article↗
PubMed1999

A model for laparoscopic aortic aneurysm resection.

BACKGROUND: The laparoscopic treatment of abdominal aortic aneurysm (AAA) could improve the perioperative course of patients suffering from this disease. The goal of the current experiment was to develop an animal model that could simulate many of the difficulties encountered in the treatment of human AAA. METHODS: Twelve piglets were submitted to a laparotomy. An AAA was created by suturing a 12- by 5-cm piece of knitted dacron to an aortotomy. Four to 15 days later, the piglets underwent the laparoscopic treatment of their AAA. RESULTS: All procedures were completed successfully. The average duration of the laparoscopic intervention was 210 min (range, 150-300 min). Aortic cross-clamping took 55 min (range, 38-72 min). Blood loss averaged 150 ml (range, 80-250 ml). During each procedure, four to six lumbar arteries were treated by intraluminal aortic clip application. Intraoperative complications consisted of one splenic trauma, one anastomotic stenosis, and one case of bleeding from a lumbar vein. CONCLUSION: Laparoscopic AAA resection is feasible in this animal model, which presents similarities to human AAA.

Anastomosis, Surgical↗
PubMed1999

Impregnated polyester arterial prostheses: performance and prospects.

Impregnated polyester arterial prostheses have gained wide acceptance by most vascular surgery teams, probably because these prostheses are easy to use, without any preclotting. We offer here a synthesis of the main studies that have appraised the experimental and clinical performance of these prostheses, and we delineate their major prospects.

Animals↗
PubMed1999

Chemotherapy cytotoxicity of human MCF-7 and MDA-MB 231 breast cancer cells is altered by osteoblast-derived growth factors.

One-third of women with breast cancer will develop bone metastases and eventually die from disease progression at these sites. Therefore, we analyzed the ability of human MG-63 osteoblast-like cells (MG-63 cells), MG-63 conditioned media (MG-63 CM), insulin-like growth factor I (IGF-I), and transforming growth factor beta 1 (TGF-beta1) to alter the effects of adriamycin on cell cycle and apoptosis of estrogen receptor negative (ER-) MDA-MB-231 and positive (ER+) MCF-7 breast cancer cells, using cell count, trypan blue exclusion, flow cytometry, detection of DNA fragmentation by simple agarose gel, and the terminal deoxynucleotidyl transferase (TdT)-mediated nick end-labeling method for apoptosis (TUNEL assay). Adriamycin arrested MCF-7 and MDA-MB-231 cells at G2/M phase in the cell cycle and inhibited cell growth. In addition, adriamycin arrested the MCF-7 cells at G1/G0 phase and induced apoptosis of MDA-MB-231 cells. Exogenous IGF-I partially neutralized the adriamycin cytotoxicity/cytostasis of cancer cells. MG-63 CM and TGF-beta1 partially neutralized the adriamycin cytotoxicity of MDA-MB-231 cells but enhanced adriamycin blockade of MCF-7 cells at G1/G0 phase. MG-63 osteoblast-like cells inhibited growth of MCF-7 cells while promoting growth and rescued MDA-MB-231 cells from adriamycin apoptosis in a collagen co-culture system. These data suggest that osteoblast-derived growth factors can alter the chemotherapy response of breast cancer cells. Conceivably, host tissue (bone)-tumor cell interactions can modify the clinical response to chemotherapy in patients with advanced breast cancer.

Antineoplastic Agents↗
PubMed1999

Experimental laparoscopic aortobifemoral bypass with end-to-side aortic anastomosis.

The goal of this animal experiment was to demonstrate the feasibility of laparoscopic end-to-side aortic anastomosis, which is mandatory in certain cases presenting with aortoiliac occlusive disease. Six piglets were submitted to laparoscopic approach of the aortoiliac vessels using the "apron" technique. After clamping the infrarenal aorta with a laparoscopic Satinsky clamp, a 3-cm end-to-side laparoscopic aortic anastomosis was constructed. Mean operative and dissection times were 198 (170-240) and 92 (75-105) min, respectively, with a mean blood loss of 86 (50-120) mL. Mean preoperative and postoperative hematocrits were 38 (3448) and 38 (34-46). Aortic cross-clamp and anastomotic times were 51 (40-65) and 44 (35-60) min, respectively. No extra sutures were needed to secure the anastomoses. At autopsy, all the anastomoses were patent without stenoses. Results indicate the feasibility of laparoscopic aortobifemoral bypass with an end-to-side aortic anastomosis.

Anastomosis, Surgical↗
PubMed1998

Osteoblast-derived survival factors protect PC-3 human prostate cancer cells from adriamycin apoptosis.

OBJECTIVES: Hormone-independent and cytotoxic drug-resistant tumor growth in osteoblastic metastases defines poor survival in patients with advanced prostate cancer. Therefore, we analyzed the ability of human osteoblast-like cells (MG-63 cells) and MG-63 conditioned media (MG-63 CM) to protect PC-3 human prostate cancer cells from adriamycin cytotoxicity in vitro. METHODS: Adriamycin cytotoxicity was assessed in MG-63 osteoblast-like and PC-3 prostate cancer monolayer and three-dimensional collagen coculture systems using the DNA content and trypan blue exclusion assays, analysis of indexes of cell cycle by flow cytometry, determination of DNA fragmentation on simple agarose gel and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and immunocytochemistry. RESULTS: Adriamycin (100 nM) arrested both the PC-3 and MG-63 cells at the G2/M phase in the cell cycle but induced apoptosis only in PC-3 cells, as assessed by flow cytometry, trypan blue exclusion, and agarose gel. Optimal doses of MG-63 CM (50 microg/mL), insulin-like growth factor I (50 ng/mL), and transforming growth factor-beta-1 (25 ng/mL), as determined by DNA content assay, partially neutralized the adriamycin cytotoxicity of PC-3 cells detected by flow cytometry and trypan blue exclusion. In addition, MG-63 cells rescued PC-3 cells from adriamycin apoptosis in the three-dimensional type I collagen gel coculture system, as analyzed by TUNEL assay. CONCLUSIONS: These data suggest that osteoblast-like cells and osteoblast-derived growth factors can optimize survival of metastatic prostate cancer cells, thereby helping to develop cytotoxic drug-resistant growth in vitro.

Biological Factors↗
PubMed1994

In vitro exposure of a novel polyesterurethane graft to enzymes: a study of the biostability of the Vascugraft arterial prosthesis.

The biostability of the Vascugraft arterial prosthesis, a porous synthetic graft made by a novel spinning process from a unique poly(ester urethane) polymer, has been studied by means of an in vitro enzyme incubation technique. Samples of the Vascugraft were exposed to buffered solutions of collagenase and pancreatin, as well as the buffer solutions alone, for periods of up to 100 days at 37 +/- 1 degrees C. On removal and after cleaning, a number of different analytic methods, including X-ray photoelectron spectroscopy for chemical analysis (ESCA), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), scanning electron microscopy (SEM), interference microscopy, moisture content and contact angle measurements, were used to examine the changes in chemical structure and surface morphology of the samples. During incubation in both enzymes the molecular weight of the polyurethane appeared to decrease in the presence of enzyme but increase in the presence of buffer. Further microphase separation in the polyurethane material developed during incubation in buffer solutions. Such changes in microstructure were associated with increased surface hydrophilicity, increased moisture content and a significant improvement in the extent of order and preferred orientation of the hard segment domains within the fibres. In the sampling depth of about 5 nm, both enzymes decreased the carbonate group content at the surface of the prosthesis to as little as 40% of their original values. The results from ATR-FTIR and DSC demonstrated that this phenomenon was limited primarily to the soft segment phase. While the Vascugraft prosthesis did exhibit some limited chemical modifications on exposure to concentrated enzyme solutions, nevertheless such changes were confined to the surface layer of the polyurethane microfibres. The importance and significance of those results will be more adequately determined by in vivo investigation.

Blood Vessel Prosthesis↗
PubMed1991

Effects of fibroblasts and basic fibroblast growth factor on facilitation of dermal wound healing by type I collagen matrices.

Healing of large open dermal wounds is associated with decreased values of the tensile strength even up to 6 months post-wounding. Results of previous studies have shown that healing is facilitated in the presence of a type I collagen sponge by promoting deposition of newly synthesized large-diameter collagen fibers parallel to the fibers of the sponge. In this study healing is evaluated in dermal wounds treated with a collagen sponge seeded with fibroblasts or coated with basic fibroblast growth factor (bFGF). Experimental results indicate that the presence of a collagen sponge results in increased wound tensile strength and increased collagen fiber diameters in the upper dermis 15 days post-wounding in an excisional guinea pig dermal wound model. In comparison, dermal wounds treated with collagen sponges seeded with fibroblasts or coated with bFGF showed increased tensile strengths 15 days postimplantation and increased degree of reepithelialization. These results indicate that fibroblast seeding and bFGF coating in conjunction with a type I collagen sponge matrix facilitate early dermal and epidermal wound healing.

Animals↗
PubMed1981

Course of the initial epithelial lesions associated with autologous bile duct replacement. Experimental study in rats.

Mucosal lesions and healing of the common bile duct were analyzed after various chemical and surgical insults in the rat by means of histologic and scanning electron microscopic investigations. Autogenous bile duct replacement is rapidly associated within the first 72 postoperative hours with complete epithelial cell desquamation, and its precocious consequence is biliary sludge. These lesions also occurred when the bile flow was diverted; the extrinsic devascularization and denervation did not produce extensive epithelial cell loss. Heparin perfusion within the biliary tree or the induction by glycerol of epithelial cell loss before bile duct transplantation is suggested in order to avoid extensive biliary sludge after bile duct transplantation.

Animals↗
PubMed1981

Effects of glycerol pretreatment upon biliary or venous grafts in bile duct replacement.

With the use of microsurgical procedures, sequential studies have been done to compare the short and long term outcome of the bile duct and the femoral vein as autogenous bioprostheses of the bile duct. Nonpretreated grafts of both types are associated with an early superficial cell loss, either epithelial or endothelial. An initial biliary sludge resulted with further consequences, that in biliary stasis, lithiasis and biliary cirrhosis. Both grafted ducts became epithelialized but were the site of an extensive inflammatory reaction followed by fibrosis within the underlying connective tissue and retraction of the graft. On the contrary, pretreatment of the grafts by immersion in concentrated glycerol allowed the initial cell shedding to occur before implantation. The process of epithelialization and glandular formation was not altered in these conditions, whereas the inflammatory and fibrotic reaction in the duct wall was reduced or absent.

Animals↗
PubMedDate not supplied

Development of a parallel plate flow chamber for studying cell behavior under pulsatile flow.

The design of a new parallel plate perfusion chamber for cell behavior studies involving pulsatile flowrates is presented. It was based on fluid mechanical considerations to ensure a region of regular and uniform shear stress at the wall. A numeric solution of the flow was performed to study the effect of pulsating flow on the entrance length. Dye injection investigations in the chamber showed laminar and uniform flow in the culture region under steady state conditions.

Cell Adhesion↗
PubMedDate not supplied

Three-dimensional type I collagen gel system containing MG-63 osteoblasts-like cells as a model for studying local bone reaction caused by metastatic cancer cells.

We inoculated the KLE human endometrial cancer, MCF-7 and ZR-75 human breast cancer, and PC-3 human prostate cancer cells into three-dimensional type I collagen gel system that contained uniformy dispersed MG-63 osteoblast-like cells. Then, we analyzed the morphological evidence of osteoblasts reaction, local invasion around the inoculated cancer cells and expression of the cathepsin D and urokinase-type plasminogen activator (uPA) around the sites of inoculation using immunocytochemistry. The prostate cancer cells produced morphological evidence of blastic reaction presented as an increased number of MG-63 osteoblasts and increase density of type I collagen around the sites of inoculation with PC-3 cells. The inoculated MCF-7 and ZR-75 cells decreased the density of type I collagen and number of osteoblasts and invaded the collagen gel around the sites of inoculation. The KLE endometrial cancer cells and cell-free media produced no reaction at the inoculation sites suggestive of cancer cell-specific interactions with osteoblasts in this system. The expression of uPA was remarkably higher at the inoculation sites of PC-3 cells as compared with those of the other cancer cells. Cathepsin D expression was higher at the sites of inoculation with KLE, MCF-7 and PC-3 cancer cells. MG-63 osteoblasts contained relatively low expression of uPA and cathepsin D. We conclude that this collagen gel system is a useful model for studying the morphological evidence of local invasion and osteoblasts reaction produced in response to local growth of metastatic cancer cell in vitro.

Bone Neoplasms↗