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Biomedical subjects

M J Gimeno

Publications and source records attributed to M J Gimeno.

At least 19 recordsLinked to original sources
PubMed2005

Cell therapy: a therapeutic alternative to treat focal cartilage lesions.

BACKGROUND: Human mesenchymal stem cells (MSCs) are present in most of the tissue matrix, taking part in their regeneration when injury or damage occurs. The aim of this study was to investigate the presence of cells with pluripotential characteristics in synovial membranes from osteoarthritic (OA) patients and the capacity of these cells to differentiate to chondrocytes. METHODS: Synovial membranes (n = 8) from OA patients were digested with collagenase. Isolated cells were cultured with DMEM, 20% FBS, and FGFb10 ng/mL. Cells from second subculture were used to carry out phenotypic characterization experiments (flow cytometry analysis with 11 monoclonal antibodies) and chondrogenic differentiation experiments(micropellet cultured in chondrogenic medium). Chondrogenic differentiation of cells was assessment by quantification of cartilage extracellular matrix components by following techniques: Safranin O, Toluidine Blue, and Alcian Blue stains to detect proteoglycans and immunohistochemistry to detect type I and II collagen. RESULTS: Flow cytometry analyses showed that in our population more than 90% of cells were positive for MSC markers: CD29 (95%), CD44 (90%), CD73 (95%), CD90 (98%). Cells were negative for hematopoietic markers (CD11b, CD34, and CD45). Furthermore, cells showed positive stain to multipotent markers such as CD117 (c-kit) (98%), CD166 (74%), and STRO-1 (88%) and to quiescent satellite cells like PAX-7 (35%). The micropellet analyses showed that the culture of these cells with TGFbeta-3 for 2 and 3 weeks stimulates proteoglycan and collagen type II synthesis. Both molecules are characteristic of hyaline articular cartilage. CONCLUSION: In this work, we demonstrate the presence of a cellular population with MSC characteristics in synovial tissue from OA patients. As MSC takes part in reparative processes of adult tissues, these cells could play an important role in OA pathogenesis and treatment.

Antigens, CD↗
PubMed2005

[Diffuse pulmonary calcification in a patient with renal insufficiency].

We report the case of a 37-year-old man with chronic renal insufficiency, on hemodialysis, with no respiratory symptoms but whose chest radiograph showed parenchymal consolidation in the middle and upper lung fields. High resolution computed tomography showed a high-attenuating diffuse alveolar pattern that indicated calcium deposits. Bronchoscopy revealed metastatic calcification on the interalveolar septa and bronchiolar and arteriolar. The present report, based on radiologic and bronchoscopic findings, describes the pathogenesis and anatomical distribution of the patient's diffuse pulmonary calcification.

Adult↗
PubMed2004

[Producing intravenous medications in a pharmacy].

The authors explain the different intravenous mixtures and the types of preloaded syringes elaborated in a centralized unit, analysing their profitability and evaluating their repercussion on the daily work nurses have to perform. This study was carried out in the Hospital de Poniente in Almeria, a county hospital which has 165 beds. The hospital authorities defined those medications which were chosen to be prepared in a centralized unit in the Pharmacy Service of the hospital and they drew up a list/guide of their corresponding conservation conditions. The authorities determined the time which nursing personnel in the various hospital units would employ in the elaboration of these medications and compared that with the time employed in the Pharmacy Service.

Drug Compounding↗
PubMed2003

A novel controlled drug-delivery system for growth hormone applied to healing skin wounds in diabetic rats.

Controlled release systems for drugs, hormones and growth factors can be particularly useful in tissue repair processes. These systems act as a biodegradable support containing the substance to be delivered, allowing their gradual release. In the past years, the local application of growth factors has acquired special relevance as a therapeutic option for use in subjects who show deficient tissue scarring, the hormone dose being the limiting factor for its success. In this study, the in vitro biocompatibility of a copolymer formed by vinylpyrrolidone and 2-hydroxyethyl methacrylate, used as an administration vehicle for hGH, was evaluated. The system was then tested in vivo in terms of its capacity for healing incisional wounds in healthy and diabetic rats. For the in vitro studies, polymer and hormone degradation rates were determined, and polymer biocompatibility was evaluated in fibroblast cultures. In the in vivo experiments, an incision was made in the back of the animals, and polymers discs with/without hGH, were introduced in the aperture. Morphological, immunohistochemical and morphometric evaluations were performed on wound tissue specimens 3-10 days after surgery. In vitro, the polymer was found to be biodegradable and showed no toxic effects on fibroblasts, the hormone being slowly released to the culture medium. In untreated diabetic rats, a delayed skin scarring and cell response were observed, compared to that noted in healthy animals. Skin closure, keratinisation and fibrosis occurred earlier in the presence of the polymer-hGH system. The use of this co-polymer as an administration vehicle for hGH improves the wound scarring process in the pathological setting of diabetes.

Animals↗
PubMed2003

Modulatory role of IL10 in endothelial cell damage and platelet adhesion.

This study explores the possibility of a regulatory role for cytokine IL-10 in platelet aggregation as an active vascular repair mechanism. Endothelial cells from human umbilical cord vein were cultured in the presence of different IL-10 concentrations (0-100 ng/ml). Platelet-rich plasma was then added to these cultures and allowed to act for 30 minutes. To rule out blood plasma involvement, washed platelets were also incubated with IL-10 (0-100 ng/ml). Changes in endothelial cell morphology were observed depending on the IL-10 concentration used; apoptotic cells appearing at the highest IL-10 concentration. Greatest platelet adhesion was noted at the highest IL-10 concentration. It was concluded that, in this in vitro model, low IL-10 levels do not affect cell viability or the pattern of platelet adhesion, but at high doses, this cytokine induces cell death and enhances platelet deposition.

Apoptosis↗
PubMed2002

Mechanical and enzymatic thrombolysis for massive pulmonary embolism.

PURPOSE: To assess the efficacy and safety of mechanical fragmentation combined with intrapulmonary thrombolysis in massive pulmonary thromboembolism (PTE) with hemodynamic impairment. MATERIALS AND METHODS: Fifty-nine patients diagnosed with massive PTE with hemodynamic impact were treated. The initial clinical symptoms were shock in 23 patients (38.9%), syncope in eight (13.5%), and dyspnea at rest in 28 (47.4%). Mean O2 saturation was 67.8%. Mean pulmonary artery pressure (PAP) was 42.1 mm Hg. During fragmentation, thrombolysis was administered in the form of a urokinase bolus of 200,000-500,000 U in 57 patients and 20 mg of recombinant tissue plasminogen activator (rt-PA) in two patients. The mean urokinase dose used was 2,500,000 IU, whereas the total dose of rt-PA was 100 mg. Heparin sodium infusion was performed to reach activated partial thromboplastin time ratios of 2. The follow-up consisted of clinical assessment, pulmonary scintigraphy, and echocardiography. The patients received treatment with dicoumarin for 6 months after the procedure. RESULTS: Clinical improvement was seen in 56 patients (94%). Three patients died. The mean PAP after the treatment was 21.8 mm Hg. The mean posttreatment Miller index was 0.35. Technical success was achieved in all cases and clinical symptoms improved in all cases except those in which the patients died. Pulmonary scintigraphy showed improved perfusion in all cases. Echocardiography was performed after 3-6 months, showing a mean pressure of 22.8 mm Hg (corrected values). There were no signs of recurrent PTE or arterial hypertension in the follow-up. CONCLUSION: The data provided confirm the efficacy and safety of mechanical fragmentation and pharmacologic thrombolysis in the treatment of massive PTE with hemodynamic impairment, showing improvement of symptoms and a decrease in PAP.

Adult↗
PubMed2001

Animal experience in the Günther Tulip retrievable inferior vena cava filter.

PURPOSE: To assess the retrievability of the Günther Tulip temporary inferior vena cava filter from a technical viewpoint, and consider the histopathologic changes that occur at the anchoring site of the filter prongs to the vein endothelium in Landrace pigs. METHODS: Twenty-two Günther Tulip retrievable filters were inserted in 22 experimental Landrace pigs via the jugular vein. Device implantation time was 0, 3, 7, 12, 14, 15, 16, 20, 30, 35 and 56 days. Study subjects were divided into two groups. In one group the filter was retrieved percutaneously via the jugular vein whereas in the other group it was removed surgically. The specimens obtained (vena cava and filter) were histopathologically examined. Prior to filter retrieval, a venacavography was obtained in all cases. Degree of retrieval difficulty was rated as follows: no difficulty (N), slight (S), mild (M), high (H) and unretrievable (U). RESULTS: Of the 22 implanted filters, 11 should have been removed percutaneously but this was impossible in three cases (U). In four cases the device was retrieved with no difficulty (N); in two cases the degree of difficulty was mild (M) and in other two it was high (H) and slight (S) respectively. Retrieval difficulties were observed after 16 days. Starting from day 20, there was evidence of fibrosis with thick intimal proliferation and total filter prong involvement, which accounts for the difficulty in retrieving the device. CONCLUSIONS: It is advisable not to exceed a filter retrieval time of 16 days in view of the fibrotic changes reported. It might be necessary to perform a larger study with more animals and with retrieval times between 14 and 20 days.

Animals↗
PubMed2001

Fibroblasts from the transversalis fascia of young patients with direct inguinal hernias show constitutive MMP-2 overexpression.

OBJECTIVE: To determine the expression pattern of certain metalloproteinases (MMPs) known to be involved in the degradation of the extracellular matrix in cultured fibroblasts from the transversalis fascia (TF) of patients with inguinal hernia. SUMMARY BACKGROUND DATA: Inguinal hernia is a common pathology, the cause of which remains unknown. It is, however, clear that the TF is one of the anatomical structures that may impede the formation of hernias, and particularly the direct type of hernia. In previous studies the authors found enhanced MMP-2 expression in TF specimens in vivo. The persistence of increased expression in cultured fibroblasts might support the idea of a genetic defect as the cause for this pathology. METHODS: Fibroblasts from the TF of patients with direct and indirect inguinal hernia were cultured and compared with those obtained from control TF in terms of MMP (MMP-2 and MMP-9) expression. RESULTS: Significant active MMP-2 expression was shown by TF fibroblasts from young patients with direct hernias. These findings were confirmed by immunosorbent assay, immunoblotting, and zymography of the fibroblast culture media. No MMP-9 expression was detected. CONCLUSION: These results indicate that MMP-2 may be involved in the TF matrix degradative process in patients with direct hernia. The persistence of changes in MMP-2 levels in the cell cultures appears to suggest a genetic defect or irreversible change as the origin of this pathology rather than environmental factors, which may later participate in the development of the hernial process.

Adult↗
PubMed2001

Function of inflammatory cells and neoral cyclosporin-A in heart transplant-associated coronary vasculopathy.

The role of Sandimmun Neoral (S-n) and the immune response in transplant-associated coronary vasculopathy (TACV) was evaluated in a Lewis (Lew)-to-Fischer-344 (F344) rat abdominal heterotopic heart transplant model. Some of the transplant recipients were treated with S-n (5mg/kg/day) for 14 days post-transplant, or until sacrifice. Grafts were subjected to immunohistochemical (ED1, CD4, CD8 and alpha-actin+ cells) analysis from day 7 to 100 post-transplant. Singenic controls did not develop TACV, irrespective of whether they had received the drug or not. TACV was detected in Lew-F344 transplants regardless of S-n administration with participation of ED1+, CD8+ and alpha-actin+ cells, although its incidence was lower in animals receiving prolonged S-n treatment. In this model, accelerated arteriosclerosis of the graft appeared to be related more to the rejection effect than to the action of the immunosuppressive agent.

Actins↗
PubMed2001

Potential role of a new anti-beta3 integrin antibody in the development of intimal hyperplasia after vascular surgery: an in vitro smooth muscle cell model.

The occurrence of intimal hyperplasia after vascular surgery is an ongoing concern in current clinical practice. Among the many factors involved in the development of this pathology, platelet adhesion and myointimal proliferation play a major role. Both these processes are mediated by integrins (mainly alphavbeta3 integrins). Over the past years, several substances have been designed to delay or inhibit the cell proliferation that leads to hyperplasia and mainly include monoclonal antibodies directed against integrins. The aim of the present study was to evaluate the effects of an antibody denoted P37 (anti beta3 integrin) on human smooth muscle cells (SMC) and its role in blocking the B3 subunit. To this end, SMC from human umbilical artery were cultured in the presence or absence of the cell substrate vitronectin (VN) and incubated with P37. After 4 days of treatment, determination was made of cell proliferation and migration. Smooth muscle cells grown on VN showed increased proliferation and migration compared to control VN-free cultures. However, the presence of P37 in the culture medium inhibited proliferation and reduced migration. Combined treatment with VN and P37 led to improved proliferation but VN was unable to reverse the effects on migration observed in the former cultures. Results suggest that in vitro, P37 is capable of blocking human SMC beta3 integrins and thus impedes cell proliferation and migration These findings may have clinical implications related to modulation of the development of hyperplasia.

Antibodies↗
PubMed2001

[Ocular changes associated with connective tissue disorders: role of the elastic and collagen components].

Every day, the emerging fields of genomics and proteomics provide new information about both normal and pathological processes, among which, the extracellular matrix appears to play a significant role. Over the past decade, the classic fibrillar components of the matrix, collagen and elastin, have been the subject of extensive research leading to a wealth of information which is far form being fully interpreted. Although the basic composition and structure of the matrix components has been well established, today more than twenty five different varieties of collagen have been described, and elastic fibers are currently described as polymeric complexes, composed of at least 19 different proteins in their microfibrillar and amorphic portions. Mutations in three of the genes coding for some of the most abundant proteins in the elastic fibers give rise to a wide range of elastic tissue phenotypes, from skeletal or dermal anomalies to vascular or ocular defects. In this review, our aim was to gain insight into the fibrillar component of the extracellular matrix in an attempt to improve our understanding of certain ocular disorders.

Collagen↗
PubMed2000

Rapid thawing increases the fragility of the cryopreserved arterial wall.

OBJECTIVE: To extend present knowledge of the biomechanical and structural changes which occur in the cryopreserved, rapidly thawed arterial wall. MATERIALS AND METHODS: Minipig iliac arterial segments were cryopreserved at -196 degrees C in either minimum essential medium or Wisconsin solution. Fresh segments served as the control group. After 1 month, the specimens were rapidly thawed (37 degrees C) and processed for biomechanical, ultrastructural, morphological and immunohistochemical (MMP-1, MMP-2, MMP-3 and MMP-9) analysis. Visualisation of apoptotic cells was performed by TUNEL method. For the mechanical distension analysis, an in vitro circuit was designed. RESULTS: The cryopreserved segments showed a 42% incidence of spontaneous fracture and the appearance of microfractures which affected the endoluminal third of the vessel. An accumulation of liquid in the subelastica was observed. An increased expression of wall-degradative enzymes (mainly MMP-2) was also observed following cryopreservation. No significant differences were detected in the proportional elasticity module or tensile strength of the specimen groups. No differences in mechanical distension were observed between groups after the vessel segments were subjected to the pulsatile circuit flow for 72 h. Cell damage was most intense in the specimens cryopreserved in Wisconsin solution. CONCLUSIONS: Cryopreservation in both the solutions employed, followed by rapid thawing, induce changes in the permeability which increase the fragility of the cryopreserved arterial wall. Both increased expression of wall-degradative enzymes and accumulation of liquid may contribute to graft failure after implantation.

Adenosine↗
PubMed2000

Evaluation of the smooth muscle cell component and apoptosis in the varicose vein wall.

This study was designed to evaluate the role of the smooth muscle cell and the apoptosis in the pathogenesis of the varicose vein. Segments of saphenous vein were obtained from healthy subjects and from those with varicose veins. The vein specimens were subdivided according to subject age (younger or older than 50 years) and according to the varicose vein source (distal or proximal). Morphological, ultrastructural, cell proliferation (anti-PCNA method) and cell death (TUNEL method) analysis were performed. The walls of healthy, control vein specimens acquired a more collagenous and papillomatous appearance with age. A slight increase in the number of TUNEL-positive cells was also observed in specimens from older subjects. The proportion of apoptotic cells was much greater in the varicose veins than in control specimens. Most cellular alterations were seen in proximal varicose segments obtained from young subjects. These specimens showed hypertrophic areas with a high degree of cellularity (both in the media and in the thickened intima). The highest proportion of apoptotic cells and collagenisation were also observed in these areas. The enhanced number of apoptotic cells in varicose veins observed mainly in proximal/young vein specimens could be responsible, at least in part, for the acceleration of the final fibrosclerotic process characteristic of the varicose vein wall.

Adult↗
PubMed1999

Arterial damage induced by cryopreservation is irreversible following organ culture.

OBJECTIVES: The aim of the present study was to investigate the changes which occur to the arterial wall following cryopreservation and thawing and to determine whether these changes are reversible after a week of culture in an organ bath. MATERIALS AND METHODS: Rat iliac arterial segments were cryopreserved. Once thawed, the arterial segments were cultured for a period of 0, 1, 2, 4 or 7 days. Freshly isolated rat iliac vessels cultured for 7 days served as the control group. Evaluation was made of ultrastructural changes, the expression of metalloproteinase activity (MMP-1, MMP-3 and MMP-9) and the apoptotic state of cells. RESULTS: The freezing-thawing process induced damage to the arterial segments compared to fresh control vessels. After 1 week of culture, arteries showed a high degree of tissue degeneration. Only a few individual endothelial cells remained on the luminal surface. There was a gradual increase in the proportion of apoptotic cells. The sequential expression of MMP-1 during the first 2 days and subsequent expression of MMP-3 and MMP-9 were of most significance. CONCLUSIONS: Cryopreservation induced damage to the vessels which could not be reversed by organ culture. The changes observed in the expression of metalloproteinases may be indicative of the degenerative process which occurs in the extracellular matrix.

Animals↗
PubMed1999

Role of macrophages in myocardial apoptosis following cardiac transplant. Influence of immunosuppressive treatment.

Cytotoxic T cells may induce myocardial apoptosis by histiocyte activation during rejection following allogenic heart transplant. The aim of the present investigation was to evaluate the macrophage response and its relationship to the programmed death of cardiomyocytes in rejection and during cyclosporin-A (CsA) treatment. An abdominal, heterotopic heart transplant rat model was used establishing two groups: singenic (ST) and allogenic (AL) transplant. 5 mg/kg/day (s.c.) CsA (Sandimun) was administered to half of the animals in each group. Morphological and structural analysis was performed 7, 14, 21, 30, 50 and 100 days post-transplant. Macrophages were detected using the monoclonal antibody (ED1). The TUNEL method was used to visualise apoptotic cells. Two weeks after ST in animals without immuno-suppressive treatment, the transplanted myocardium had been extensively infiltrated by inflammatory cells, many of which were ED1-positive. At 21 days follow-up, the number of labelled cells had fallen. In animals treated with CsA the amount of ED1-positive cells was lower than that seen in the anterior group. Only a few isolated cells of the infiltrate were TUNEL-positive. In the AT group, rejection took place between 9-15 days in the untreated animals. The myocardium was highly infiltrated by mononuclear cells. Some were ED1-positive. Small groups of apoptotic cells were visible in the infiltrate and in some vessel lumens. Rejection was resolved in animals treated with CsA. The macrophage response diminished during follow-up in a similar way to that occurring in the ST. Few cells showed TUNEL positivity. It may be concluded that: a) CsA treatment diminishes the amount of infiltrated macrophages; b) animals receiving ST or AT, show a low level of apoptosis; c) in the present model, the apoptosis of cardiomyocytes does not appear to be induced by macrophages; and d) in this model it is not possible to relate apoptosis and rejection.

Animals↗
PubMed1998

Coating PTFE vascular prostheses with a fibroblastic matrix improves cell retention when subjected to blood flow.

An investigation was made into the effect of blood flow on endothelial cells (EC) and mesothelial cells (MC) seeded on a vascular expanded polytetrafluoroethylene (ePTFE) prosthesis coated with a fibroblastic matrix. Endothelial cells were obtained from the external jugular vein and MC from the omentum. To test the performance of prostheses, a custom designed, femoral "ex vivo" circuit was developed in mongrel dogs. Four study groups were established: a control group, A1, where prostheses were uncoated and seeded with EC; a second control group, A2, where prostheses were uncoated and seeded with MC; group B1 where prostheses were coated with a fibroblastic matrix and seeded with EC; and group B2 where coated prostheses were seeded with MC. All cells were labeled with 111Indium oxine (10 microCi/mL) before seeding. After the seeded cells had formed a monolayer on the ePTFE prostheses (which took approximately 24 h) the prostheses were placed in the "ex vivo" circuit. The rates of blood flow to which prostheses were exposed were measured at the point of inflow (117.5 +/- 12.50 mL/min, mean +/- SD) and outflow (72.6 +/- 14.3 mL/min). MC showed a greater baseline radionuclide uptake than did EC. The cells of groups B1 and B2 adhered sufficiently to the fibroblastic matrix and covered enough of the prosthetic surface to be positioned in the "ex vivo" circuit (76.90 +/- 8.24% surface covered in EC-seeded prostheses and 71.65 +/- 6.23% in MC-seeded prostheses). After exposure to blood flow the quantity of radionuclide-labeled cells and the prosthetic surface covered by them were greatly reduced though the fibroblast-coated prostheses showed greater cell retention.

Animals↗
PubMed1997

Mesothelial versus endothelial cell seeding: evaluation of cell adherence to a fibroblastic matrix using 111In oxine.

OBJECTIVES: The aim of this study was to compare the behaviour of mesothelial cells (MC) to that of endothelial cells (EC) when seeded onto a PTFE, prosthesis coated with a fibroblastic matrix. DESIGN, MATERIAL AND METHODS: Three study groups were examined: a control group (Control) of PTFE prostheses with a fibroblast matrix (n = 8); Group EC, PTFE prostheses seeded with EC on a fibroblastic matrix (n = 8); and Group MC, PTFE, prostheses seeded with MC on a fibroblastic matrix (n = 8). All cell types were labelled with 111In (100 microCi/ml) 24 h after seeding, when the cells had formed a monolayer on the prosthetic surface. Radioactive levels were measured at 2, 4, 6, and 24 h. RESULTS: Both EC and MC showed optimal adherence. The MC had a better radioactive uptake and retention than the EC. The number of EC and MC cells that remained adherent to the matrix was large enough to ensure complete covering of the prosthetic surface. CONCLUSION: The use of MC is therefore feasible as an optimal alternative for achieving a natural covering on vascular prostheses prepared with a fibroblastic matrix.

Blood Vessel Prosthesis↗