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1.
Angiogenesis ; 21(4): 883-900, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30014172

RESUMEN

VEGF induces normal or aberrant angiogenesis depending on its dose in the microenvironment around each producing cell in vivo. This transition depends on the balance between VEGF-induced endothelial stimulation and PDGF-BB-mediated pericyte recruitment, and co-expression of PDGF-BB normalizes aberrant angiogenesis despite high VEGF doses. We recently found that VEGF over-expression induces angiogenesis in skeletal muscle through an initial circumferential vascular enlargement followed by longitudinal splitting, rather than sprouting. Here we investigated the cellular mechanism by which PDGF-BB co-expression normalizes VEGF-induced aberrant angiogenesis. Monoclonal populations of transduced myoblasts, expressing similarly high levels of VEGF alone or with PDGF-BB, were implanted in mouse skeletal muscles. PDGF-BB co-expression did not promote sprouting and angiogenesis that occurred through vascular enlargement and splitting. However, enlargements were significantly smaller in diameter, due to a significant reduction in endothelial proliferation, and retained pericytes, which were otherwise lost with high VEGF alone. A time-course of histological analyses and repetitive intravital imaging showed that PDGF-BB co-expression anticipated the initiation of vascular enlargement and markedly accelerated the splitting process. Interestingly, quantification during in vivo imaging suggested that a global reduction in shear stress favored the initiation of transluminal pillar formation during VEGF-induced splitting angiogenesis. Quantification of target gene expression showed that VEGF-R2 signaling output was significantly reduced by PDGF-BB co-expression compared to VEGF alone. In conclusion, PDGF-BB co-expression prevents VEGF-induced aberrant angiogenesis by modulating VEGF-R2 signaling and endothelial proliferation, thereby limiting the degree of circumferential enlargement and enabling efficient completion of vascular splitting into normal capillary networks despite high VEGF doses.


Asunto(s)
Becaplermina/metabolismo , Proliferación Celular , Células Endoteliales , Músculo Esquelético , Neovascularización Fisiológica , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Células Endoteliales/citología , Células Endoteliales/metabolismo , Ratones , Ratones SCID , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/citología , Músculo Esquelético/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo
3.
Physiol Behav ; 98(1-2): 176-85, 2009 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-19460392

RESUMEN

Stressful early life events can have short- and long-term effects on neuroendocrine and behavioural mechanisms of adaptation. Here, we investigated the effects of a single social isolation (4 h) of domestic piglets on both behavioural alterations in open-field tests and modifications in the expression of genes regulating glucocorticoid response in stress-related brain regions at 7, 21 or 35 days of age. The mRNAs of glucocorticoid receptor (GR), mineralocorticoid receptor (MR), 11ss-hydroxysteroid dehydrogenase 1 and 2 (11ss-HSD1 and 11ss-HSD2) and c-fos were analysed by real-time RT-PCR in the hypothalamus, hippocampus and amygdala. The social isolation caused both elevated stress hormone concentrations (e.g. cortisol) and open-field reactivity (e.g. locomotion, vocalisation) compared to control piglets. The enhanced behavioural and neuroendocrine activity was associated with distinct changes in gene expression in the limbic system. The hypothalamic GR, MR and 11ss-HSD1 mRNA expressions and the hippocampal 11ss-HSD1 mRNA was significantly higher in isolated piglets, whereas in the amygdala social isolation caused a significant decrease in MR mRNA expression. Isolated piglets also displayed significantly higher c-fos mRNA expression, an estimate of neuronal activation, in hypothalamus and amygdala. The mRNA alterations as well as the behavioural and hormonal pattern show an effect of social isolation on days 7 and 21, but no effect on day 35. In conclusion, a single social isolation in piglets caused age-dependent neuroendocrine and behavioural changes that indicate increased arousal and experienced distress. The present results also suggest that psychosocial stress effects should be considered for the assessment of livestock handling practices with respect to health and welfare.


Asunto(s)
Nivel de Alerta/fisiología , Conducta Animal/fisiología , Química Encefálica/genética , Química Encefálica/fisiología , Expresión Génica/fisiología , Hormonas/metabolismo , Sistemas Neurosecretores/metabolismo , Aislamiento Social/psicología , Estrés Psicológico/genética , Estrés Psicológico/metabolismo , Animales , Genes fos/fisiología , Hormonas/biosíntesis , Hormonas/genética , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipófiso-Suprarrenal/metabolismo , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Porcinos , Transcripción Genética/genética
4.
Knee Surg Sports Traumatol Arthrosc ; 17(11): 1377-83, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19305976

RESUMEN

We present a novel method to support precise insertion of engineered osteochondral grafts by pulling from the bone layer, thereby minimizing iatrogenic damage associated with direct manipulation of the cartilage layer. Grafts were generated by culturing human expanded chondrocytes on Hyaff-11 meshes, sutured to Tutobone spongiosa cylinders. Through the bone layer, shaped to imitate the surface-contours of the talar dome, two sutures were applied: the first for anterograde implantation, to pull the graft into the defect, and the second for retrograde correction, in case of a too deep insertion. All grafts could be correctly positioned into osteochondral lesions created in cadaveric ankle joints with good fit to the surrounding cartilage. Implants withstood short-term dynamic stability tests applied to the ankle joint, without delamination or macroscopic damage. The developed technique, by allowing precise and stable positioning of osteochondral grafts without iatrogenic cartilage damage, is essential for the implantation of engineered tissues, where the cartilage layer is not fully mechanically developed, and could be considered also for conventional autologous osteochondral transplantation.


Asunto(s)
Traumatismos del Tobillo/cirugía , Trasplante Óseo , Condrocitos/trasplante , Astrágalo/lesiones , Astrágalo/cirugía , Cadáver , Humanos , Implantación de Prótesis , Mallas Quirúrgicas , Técnicas de Sutura , Ingeniería de Tejidos
5.
Chirurg ; 80(2): 130-7, 2009 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-18972092

RESUMEN

AIM: Mission and organization of emergency units were analysed to understand the underlying principles and concepts. METHODS: The recent literature (2000-2007) on organizational structures and functional concepts of clinical emergency units was reviewed. An organizational portfolio based on the criteria specialization (presence of medical specialists on the emergency unit) and integration (integration of the emergency unit into the hospital structure) was established. The resulting organizational archetypes were comparatively assessed based on established efficiency criteria (efficiency of resource utilization, process efficiency, market efficiency). RESULTS: Clinical emergency units differ with regard to autonomy (within the hospital structure), range of services and service depth (horizontal and vertical integration). The "specialization"-"integration"-portfolio enabled the definition of typical organizational patterns (so-called archetypes): profit centres primarily driven by economic objectives, service centres operating on the basis of agreements with the hospital board, functional clinical units integrated into medical specialty units (e.g., surgery, gynaecology) and modular organizations characterized by small emergency teams that would call specialists immediately after triage and initial diagnostic. CONCLUSIONS: There is no "one fits all" concept for the organization of clinical emergency units. Instead, a number of well characterized organizational concepts are available enabling a rational choice based on a hospital's mission and demand.


Asunto(s)
Servicio de Urgencia en Hospital/organización & administración , Ambiente de Instituciones de Salud , Grupo de Atención al Paciente/organización & administración , Conducta Cooperativa , Atención a la Salud/organización & administración , Alemania , Guías como Asunto , Humanos , Comunicación Interdisciplinaria , Medicina , Objetivos Organizacionales , Garantía de la Calidad de Atención de Salud/organización & administración , Derivación y Consulta/organización & administración , Especialización
6.
Br J Cancer ; 96(7): 1072-82, 2007 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-17342088

RESUMEN

Cancer cells' growth in three-dimensional (3D) architectures promotes resistance to drugs, cytokines, or irradiation. We investigated effects of 3D culture as compared to monolayers (2D) on melanoma cells' recognition by tumour-associated antigen (TAA)-specific HLA-A(*)0201-restricted cytotoxic T-lymphocytes (CTL). Culture of HBL, D10 (both HLA-A(*)0201+, TAA+) and NA8 (HLA-A(*)0201+, TAA-) melanoma cells on polyHEMA-coated plates, resulted in generation of 3D multicellular tumour spheroids (MCTS). Interferon-gamma (IFN-gamma) production by HLA-A(*)0201-restricted Melan-A/MART-1(27-35) or gp 100(280-288)-specific CTL clones served as immunorecognition marker. Co-culture with melanoma MCTS, resulted in defective TAA recognition by CTL as compared to 2D as witnessed by decreased IFN-gamma production and decreased Fas Ligand, perforin and granzyme B gene expression. A multiplicity of mechanisms were potentially involved. First, MCTS per se limit CTL capacity of recognising HLA class I restricted antigens by reducing exposed cell surfaces. Second, expression of melanoma differentiation antigens is downregulated in MCTS. Third, expression of HLA class I molecules can be downregulated in melanoma MCTS, possibly due to decreased interferon-regulating factor-1 gene expression. Fourth, lactic acid production is increased in MCTS, as compared to 2D. These data suggest that melanoma cells growing in 3D, even in the absence of immune selection, feature characteristics capable of dramatically inhibiting TAA recognition by specific CTL.


Asunto(s)
Antígenos de Neoplasias/inmunología , Melanoma/inmunología , Esferoides Celulares/inmunología , Linfocitos T Citotóxicos/inmunología , Técnicas de Cultivo de Célula , Proteína Ligando Fas/genética , Proteína Ligando Fas/metabolismo , Granzimas/genética , Granzimas/metabolismo , Antígeno HLA-A1/inmunología , Antígeno HLA-A2/inmunología , Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Antígeno MART-1 , Melanoma/secundario , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de Neoplasias/inmunología , Perforina , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Esferoides Celulares/metabolismo , Esferoides Celulares/patología , Linfocitos T Citotóxicos/metabolismo , Células Tumorales Cultivadas
7.
Br J Cancer ; 90(1): 263-9, 2004 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-14710238

RESUMEN

Tumour-associated antigens (TAA)-specific vaccination requires highly immunogenic reagents capable of inducing cytotoxic T cells (CTL). Soluble peptides are currently used in clinical applications despite an acknowledged poor immunogenicity. Encapsulation into liposomes has been suggested to improve the immunogenicity of discrete antigen formulations. We comparatively evaluated the capacity of HLA-A2.1 restricted Melan-A/MART-1 epitopes in soluble form (S) or following inclusion into sterically stabilised liposomes (SSL) to be recognised by specific CTL, to stimulate their proliferation and to induce them in healthy donors' peripheral blood mononuclear cells (PBMC), as well as in melanoma-derived tumour-infiltrating lymphocytes (TIL). HLA-A2.1(+), Melan-A/MART-1-NA-8 melanoma cells served as targets of specific CTL in 51Cr release assays upon pulsing by untreated or human plasma-treated soluble or SSL-encapsulated Melan-A/MART-1 27-35 (M27-35) or 26-35 (M26-35) epitopes. These reagents were also used to stimulate CTL proliferation, measured as 3H-thymidine incorporation, in the presence of immature dendritic cells (iDC), as antigen-presenting cells (APC). Induction of specific CTL upon stimulation with soluble or SSL-encapsulated peptides was attempted in healthy donors' PBMC or melanoma-derived TIL, and monitored by 51Cr release assays and tetramer staining. Na-8 cells pulsing with SSL M27-35 resulted in a five-fold more effective killing by specific CTL as compared with equal amounts of S M27-35. Encapsulation into SSL also provided a partial (50%) protection of M27-35 from plasma hydrolysis. No specific advantages regarding M26-35 were detectable in these assays. However, at low epitope concentrations (

Asunto(s)
Antígenos de Neoplasias/inmunología , Melanoma/inmunología , Proteínas de Neoplasias/inmunología , Neoplasias Cutáneas/inmunología , Linfocitos T Citotóxicos/inmunología , Epítopos , Humanos , Inmunoterapia/métodos , Liposomas , Linfocitos Infiltrantes de Tumor/inmunología , Antígeno MART-1
8.
Hum Gene Ther ; 14(16): 1497-510, 2003 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-14577912

RESUMEN

We performed a phase I/II clinical trial in metastatic melanoma patients with an ultraviolet (UV)-inactivated nonreplicating recombinant vaccinia virus enabling the expression, from a single construct, of endoplasmic reticulum-targeted HLA-A0201-restricted Melan-A/MART-1(27-35), gp100(280-288), and tyrosinase(1-9) epitopes, together with CD80 and CD86 costimulatory proteins. Corresponding soluble peptides were used to boost responses and granulocyte-macrophage colony-stimulating factor was used as systemic adjuvant. Safety and immunogenicity, as monitored with in vitro-restimulated peripheral blood mononuclear cells by cytotoxic T lymphocyte precursor (CTLp) frequency analysis and tetramer staining, were specifically addressed. Of 20 patients entering the protocol, 2 had to withdraw because of rapidly progressing disease. Immune responses were evaluated in 18 patients (stage III, n = 5; stage IV, n = 13) and increases in specific CTLp frequencies were observed in 15. In 16 patients responsiveness against all 3 antigens could be analyzed: 7 (43%), including all stage III cases, showed evidence of induction of CTLs specific for the three epitopes, and 2 (12%) and 4 (25%), respectively, showed reactivity against two or one tumor-associated antigen. In three stage IV patients no specific CTL reactivity could be induced. Increases in CTLp frequency were detected mostly after viral vaccine injections. However, in a majority of patients final CTLp levels were comparable to initial levels. Tetramer characterization of Melan-A/MART-1(27-35)-specific CTLs during the protocol also suggested preferential expansion after recombinant virus administration. Vector-specific humoral responses, frequently undetectable in stage IV patients, did not appear to prevent tumor-associated antigen-specific CTL induction. Aside from a single occurrence of transient grade 3 leukopenia, no major clinical toxicity was reported. Seventeen of 18 patients completed the 3-month trial (one patient died before the last delayed-type hypersensitivity test). Three displayed regression of individual metastases, seven had stable disease, and progressive disease was observed in seven patients. This is the first report on the administration of a UV-inactivated recombinant vaccinia virus coexpressing five transgenes in cancer patients. The results described here, in terms of safety and immunogenicity, support the use of this reagent in active specific immunotherapy.


Asunto(s)
Vacunas contra el Cáncer/uso terapéutico , Epítopos/inmunología , Antígenos HLA-A/inmunología , Melanoma/terapia , Linfocitos T Citotóxicos/inmunología , Virus Vaccinia/inmunología , Adulto , Anciano , Antígenos CD/inmunología , Antígenos de Neoplasias , Antígeno B7-1/inmunología , Antígeno B7-2 , Vacunas contra el Cáncer/administración & dosificación , Virus Defectuosos , Femenino , Estudios de Seguimiento , Vectores Genéticos , Humanos , Antígeno MART-1 , Masculino , Melanoma/inmunología , Glicoproteínas de Membrana/inmunología , Persona de Mediana Edad , Proteínas de Neoplasias/inmunología , Vacunas Sintéticas/uso terapéutico
9.
Biotechnol Bioeng ; 84(2): 205-14, 2003 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-12966577

RESUMEN

We developed a bioreactor for automated cell seeding of three-dimensional scaffolds by continuous perfusion of a cell suspension through the scaffold pores in oscillating directions. Using quantitative biochemical and image analysis techniques, we then evaluated the efficiency and uniformity of perfusion seeding of Polyactive foams as compared to conventional static and spinner flask methods. Finally, we assessed the efficacy of the perfusion seeding technique for different scaffolds and cell types. Perfusion seeding of chondrocytes into Polyactive foams resulted in "viable cell seeding efficiencies," defined as the percentages of initially loaded cells that were seeded and remained viable, that were significantly higher (75 +/- 6%) than those by static (57% +/- 5%) and spinner flask seeding (55% +/- 8%). In addition, as compared to static and spinner flask methods, cells seeded by perfusion were respectively 2.6-fold and 3.8-fold more uniformly distributed and formed more homogeneously sized cell clusters. Chondrocytes seeded by perfusion into Hyaff-11 nonwoven meshes were 26% and 63%, respectively, more uniformly distributed than following static and spinner flask seeding. Bone marrow stromal cells seeded by perfusion into ChronOS porous ceramics were homogeneously distributed throughout the scaffold volume, while following the static method, cells were found only near the top surface of the ceramic. In summary, we demonstrated that our cell seeding perfusion bioreactor generated constructs with remarkably uniform cell distributions at high efficiencies, and was effective for a variety of scaffolds and different mesenchymal cell types.


Asunto(s)
Reactores Biológicos , Técnicas de Cultivo de Célula/métodos , Ácido Hialurónico/análogos & derivados , Animales , Células de la Médula Ósea/fisiología , Fosfatos de Calcio/química , Cartílago Articular/citología , Adhesión Celular/fisiología , Agregación Celular/fisiología , Recuento de Células , Técnicas de Cultivo de Célula/instrumentación , División Celular/fisiología , Supervivencia Celular , Células Inmovilizadas/fisiología , Condrocitos/fisiología , Interpretación Estadística de Datos , Humanos , Ácido Hialurónico/química , Poliésteres/química , Polietilenglicoles/química , Reología , Coloración y Etiquetado , Células del Estroma/fisiología , Sales de Tetrazolio/metabolismo , Tiazoles/metabolismo
10.
Swiss Surg ; 9(2): 43-53, 2003.
Artículo en Alemán | MEDLINE | ID: mdl-12723283

RESUMEN

UNLABELLED: Scientific journals currently face challenges including cost pressures caused by economic constraints, increasing rivalry among competitors, limited market potential of non-english speaking journals, increasing medical specialization with resulting market fragmentation, and internet-based competition. We therefore analyzed strategic opportunities of the journal Swiss Surgery on the basis of customer surveys and of a market analysis. RESULTS: Swiss surgeons expressed their interest in the continuation of the journal but also indicated their support for changes in its concept and for an increased use of electronic media. An international market analysis points-out the difficulties of national, non-english speaking journals in gaining impact points and in attracting authors and readers of scientific medical articles. Therefore, a journal such as Swiss Surgery should identify and use publication niches. RECOMMENDATION: The demand for a concept addressing surgical training including continuous postgraduate education was confirmed by the customers of Swiss Surgery. A corresponding offer does not presently exist in the area and could become the new focus of the journal. This change of concept may have a number of consequences: A journal focusing on surgical training and education should use the results of readers' surveys rather than impact point assignment to evaluate quality. The journal should increasingly use electronic services including data bases, pictures, videos and closed user groups to supplement the print version. At short term, however, the printed version should be continued and not be substituted by the electronic version in order to maintain the established brand "Swiss Surgery".


Asunto(s)
Actitud del Personal de Salud , Competencia Económica/tendencias , Cirugía General/tendencias , Mercadotecnía/tendencias , Publicaciones Periódicas como Asunto/tendencias , Especialización/tendencias , Estudios de Evaluación como Asunto , Predicción , Humanos , Edición/tendencias , Suiza
11.
Cancer Gene Ther ; 8(9): 655-61, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11593334

RESUMEN

The effect on immunogenicity of different tumor T cell epitope formulations was evaluated in vitro using nonreplicating recombinant vaccinia vector expressing two forms of the melanoma-associated MART-1/Melan-A antigen. The first recombinant virus expressed a minigene encoding a fusion product between an endoplasmic reticulum (ER)-targeting signal and the HLA-A201 binding 27-35 peptide. The second viral construct encoded the complete MART-1/Melan-A protein. The capacity of HLA-A201 cells infected with either viral construct to generate and to stimulate MART-1/Melan-A 27-35 specific cytotoxic T-lymphocytes (CTL), was comparatively characterized. The results obtained here with a tumor antigen confirmed the capacity of vaccinia virus-encoded ER-minigene to generate a very strong antigenic signal. In cytotoxicity assays, recognition of target cells infected with high amounts of both recombinant viruses with activated specific CTL clones, resulted in similar lytic activity. With regard to calcium mobilization, TCR down-regulation, IFN-gamma release, and T cell proliferation assays, the targeted epitope elicited 10- to 1000-fold stronger responses. Remarkably, the immunogenic difference between the two formulations, in their respective capacity to generate CTL from naive HLA-A2 peripheral blood mononuclear cells in vitro as measured by tetramer detection, was lower (2- to 3-fold). Recombinant vectors expressing complete antigens have demonstrated their capacity to generate specific responses and such vaccines might take advantage of a broader potential of presentation. However, as demonstrated here for the HLA-A201-restricted MART-1/Melan-A immunodominant epitope, nonreplicative vaccinia virus expressing ER-targeted minigenes appear to represent a significantly more immunogenic epitope vaccine formulation.


Asunto(s)
Antígenos Virales/inmunología , Epítopos/inmunología , Antígeno HLA-A2/inmunología , Melanoma/inmunología , Proteínas de Neoplasias/inmunología , Linfocitos T Citotóxicos/inmunología , Virus Vaccinia/inmunología , Presentación de Antígeno , Antígenos de Neoplasias , Calcio/metabolismo , Citotoxicidad Inmunológica , Regulación hacia Abajo , Humanos , Inmunización , Interferón gamma/metabolismo , Activación de Linfocitos/inmunología , Antígeno MART-1 , Melanoma/patología , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Proteínas Recombinantes , Linfocitos T/inmunología , Transfección , Células Tumorales Cultivadas , Vacunas Virales , Replicación Viral
12.
Int Angiol ; 20(2): 174-80, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11533526

RESUMEN

BACKGROUND: Ischaemia-induced damage of skeletal muscle may lead to side effects in orthopaedic and reconstructive surgery where tourniquet ischaemia is applied to ensure a bloodless operative field. In this study we investigated the effect of ischaemia-reperfusion injury with and without preconditioning by studying the skeletal muscle microcirculation. A further aim was to establish whether ischaemic preconditioning or pretreatment with cromakalim, a potassium channel opener reduces ischaemia-reperfusion injury. METHODS: Twenty-eight Wistar rats were randomised into four groups (n=7 per group). Group 1, control with no treatment; Group 2, two and a half hours tourniquet ischaemia followed by two hours of reperfusion to the left hindlimb. Furthermore, we pre-treated two groups prior to the ischaemia-reperfusion period; Group 3 with three short cycles of ischaemia-reperfusion (5'/5') and Group 4 pre treated with cromakalim (100 microg/kg bw). We monitored the gastrocnemius muscle blood flow in vivo. RESULTS: There were no significant changes in the skeletal muscle microcirculation and temperature at the baseline in the four groups (p=0.110). In the ischaemic reperfusion, ischaemia preconditioning and cromakalim groups, the recorded skeletal muscle microcirculation during ischaemia decreased significantly (p<0.001) with respect to the baseline. In Group 2 the microcirculation recovered rapidly after release of the tourniquet, but was significantly lower (37 percent of baseline value, p<0.001) within two hours of reperfusion. In the ischaemia preconditioning group the microcirculation as in the ischaemia-reperfusion group recovered rapidly after release of the tourniquet, although failing to reach the baseline value within two hours of reperfusion. The mean microcirculation value of the left limb was slightly higher than Group 2 but significantly lower compared to the baseline after two hours of reperfusion (p<0.001). The change in the skeletal muscle microcirculation with cromakalim after two hours of reperfusion was not significant when compared to baseline values (p>0.05). The cromakalim group after two hours reperfusion had significantly higher microcirculation values when compared with Groups 2 and 3 (p<0.001). During ischaemia-reperfusion in Groups 2-4, there was no significant alteration in the systemic haemodynamic circulation. CONCLUSIONS: This study supports the hypothesis that cromakalim reduces postischaemic skeletal muscle damage and reperfusion injury.


Asunto(s)
Antihipertensivos/uso terapéutico , Cromakalim/uso terapéutico , Precondicionamiento Isquémico Miocárdico , Daño por Reperfusión Miocárdica/terapia , Perfusión , Animales , Extremidades/irrigación sanguínea , Flujometría por Láser-Doppler , Masculino , Microcirculación/efectos de los fármacos , Modelos Animales , Modelos Cardiovasculares , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/efectos de los fármacos , Ratas , Ratas Wistar , Flujo Sanguíneo Regional/efectos de los fármacos
13.
Virchows Arch ; 439(2): 127-31, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11561752

RESUMEN

MAGE (Melanoma antigen E) family gene products encompass tumour-associated antigens (TAAs) recognised by human leukocyte antigen (HLA)-restricted specific T-cells. Agents inducing DNA demethylation, an event typically detectable in cellular de-differentiation processes, were shown to induce the expression of MAGE genes. By using a monoclonal antibody specific for MAGE family gene products, we have studied the expression of these TAAs in a group of 144 patients with invasive ductal breast cancers. Immunohistochemical data were correlated with tumour differentiation, lymphatic vessel invasion, oestrogen receptor expression, intratumoural necrosis, lymphocytic infiltration, perineural invasion, tumour microcalcifications and axillary lymph node metastases. MAGE immunoreactivity was undetectable in non-neoplastic cells. In poorly differentiated cancers positive staining was observed in 30/63 cases (47.6%) as compared with 13/51 (25.4%) and 5/30 (16.6%) in moderately and well-differentiated tumours, respectively (P<0.05). In addition, MAGE immunoreactivity was significantly correlated with lymphatic vessel invasion and intratumoural necrosis. Moreover, a significant inverse relationship with oestrogen receptor expression was also observed. However, no significant correlation could be established between MAGE immunoreactivity and defined phenotypic characteristics of tumour infiltrating lymphocytes, including expression of CD3, CD4, CD8, CD20 or granzyme B. Thus, expression of MAGE family gene products in invasive ductal breast cancers appears to be associated with poorly differentiated histological phenotypes. These data support the concept of specific immunotherapy in highly aggressive forms of breast neoplasms. Furthermore, they suggest that MAGE immunoreactivity could represent a tumour marker of potential prognostic relevance.


Asunto(s)
Neoplasias de la Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Proteínas de Neoplasias/metabolismo , Anticuerpos Monoclonales , Antígenos de Neoplasias , Biomarcadores de Tumor/análisis , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/clasificación , Carcinoma Ductal de Mama/secundario , Recuento de Células , Diferenciación Celular , Transformación Celular Neoplásica , Femenino , Humanos , Técnicas para Inmunoenzimas , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Metástasis Linfática , Antígenos Específicos del Melanoma , Invasividad Neoplásica/patología , Proteínas de Neoplasias/inmunología
16.
Hum Immunol ; 62(1): 39-49, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11165714

RESUMEN

To gain new insights into the functional interaction between DC and neoplastic cells, we have analyzed the effects of melanoma and colorectal cancer lines on the chemotaxis and the phenotype of monocyte-derived DC in vitro. Both types of tumor cells displayed effective chemoattractive capacity towards immature, but not mature DC. Furthermore, conditioned medium of discrete melanoma lines induced upregulation of CD80, CD86, MHC class I, and MHC class II molecules on immature DC. However, de novo expression of E-cadherin and strong upregulation of CD15 could also be detected in the absence of CD83 expression. Melanoma-conditioned DC exhibited an increased adhesion capacity to a melanoma cell line in vitro and did not migrate in response to SLC chemokine. Tumor-infiltrating CD15(+) cells displaying DC morphology could also be detected by immunohistochemistry in the original tumor specimens from which discrete melanoma cell lines under investigation were derived. Colorectal cancer cell lines, although able to chemoattract immature DC, were apparently unable to modulate their phenotype. Altogether our results suggest that tumor cells can attract immature DC in vitro and, eventually, modulate their phenotype. As a result, DC mobility could be severely impaired.


Asunto(s)
Quimiotaxis de Leucocito/inmunología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Inmunofenotipificación , Células Tumorales Cultivadas/inmunología , Animales , Cadherinas/biosíntesis , Cadherinas/genética , Quimiocinas/biosíntesis , Quimiocinas/genética , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/patología , Medios de Cultivo Condicionados/farmacología , Células Dendríticas/patología , Regulación Neoplásica de la Expresión Génica/inmunología , Humanos , Inmunohistoquímica , Antígeno Lewis X/análisis , Antígeno Lewis X/biosíntesis , Melanoma/inmunología , Melanoma/patología , Ratones , Regulación hacia Arriba/inmunología
17.
JPEN J Parenter Enteral Nutr ; 24(6): 337-44, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11071593

RESUMEN

BACKGROUND: The lipid component of total parenteral nutrition (TPN) has reportedly been associated with trophic effects on the intestinal mucosa and suppressive effects on the immune system. METHODS: We have challenged these hypotheses using a 7-day TPN rodent model comparing the effects of isocaloric, isonitrogenous lipid-based (TPN-lipid, 50% of calories as long-chain triacylglycerol) and carbohydrate-based TPN (TPN-CH, 100% of calories as carbohydrates) on mucosal morphology and immune function. Enterally fed animals were included to establish a baseline for immunologic read-outs. The study was performed in healthy, metabolically stable animals to avoid interference by septic or trauma-related stress factors. RESULTS: Both TPN regimens resulted in a significantly smaller weight gain (TPN-lipid, 29.8 +/- 4.0 g; TPN-CH, 30.3 +/- 4.4 g) compared with enterally fed reference animals (49.2 +/- 3.2 g; p = .007), with no difference in nitrogen balance between the TPN groups. Mucosal sucrase activity was significantly lower in both TPN groups (TPN-lipid, 8.8 +/- 1.0 x 10(-7) katal per gram (kat/g) of protein; CH: 11.9 +/- 1.6 x 10(-7) kat/g of protein) compared with enteral feeding (17.4 +/- 0.9 x 10(-7) kat/g of protein; ANOVA: p = .0007). Morphometric analysis of the small intestine revealed no differences between the two TPN groups although a significantly depressed villus height in the TPN-lipid group could be observed in comparison to enterally fed reference rats (TPN-lipid, 0.47 +/- 0.02; TPN-CH, 0.50 +/- 0.01; enteral, 0.56 +/- 0.02 mm; ANOVA: p = .0298). Light and electron microscopy revealed a normal surface architecture in all three groups of rats. Cellular immune reactivity was evaluated using a novel specific immunization protocol: animals were immunized against OVA 4 weeks before TPN. OVA-induced lymphoproliferative responses and phenotypic data from draining popliteal and mesenteric lymph nodes were evaluated after the different regimens. Results did not differ among the three groups. CONCLUSIONS: In healthy rodents, short-term lipid-based and carbohydrate-based TPN regimens lead to limited mucosal atrophy with preserved surface architecture compared with enteral feeding. However, peripheral and mesenteric cellular immune responsiveness after both TPN regimens remained comparable to enterally fed reference animals. Therefore, mesenteric and systemic cellular immune reactivity does not appear to be impaired by lipid-based or carbohydrate-based TPN.


Asunto(s)
Emulsiones Grasas Intravenosas/administración & dosificación , Mucosa Intestinal/inmunología , Nutrición Parenteral Total , Animales , Atrofia , Carbohidratos/administración & dosificación , Citometría de Flujo , Inmunidad Celular , Inmunización , Mucosa Intestinal/patología , Mucosa Intestinal/ultraestructura , Ganglios Linfáticos/citología , Ganglios Linfáticos/inmunología , Masculino , Microscopía Electrónica , Microscopía Electrónica de Rastreo , Nitrógeno/metabolismo , Distribución Aleatoria , Ratas , Ratas Wistar , Linfocitos T/inmunología , Aumento de Peso
18.
J Surg Res ; 94(1): 18-27, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11038298

RESUMEN

BACKGROUND: Ischemic preconditioning (IP) (one or more cycles each consisting of a short period of ischemia and a short period of reperfusion, before the sustained ischemia) reduces ischemia-related organ damage in heart and skeletal muscle but the underlying mechanisms are not clear. This study was intended to assess the possible involvement of K(ATP) channels and of adenosine receptors in IP of skeletal muscle in a rat model of skeletal muscle ischemia. MATERIALS AND METHODS: Groups of 8-15 rats were given the following in vivo treatments: ischemia-reperfusion (I-R: 2.5 h tourniquet-induced ischemia of the right hindlimb, then 2 h reperfusion); IP (three cycles of 5 min ischemia, then 5 min reperfusion) before I-R; cromakalim and I-R; glibenclamide, cromakalim, and I-R; glibenclamide, IP, and I-R; [R]-N(6)-[1-methyl-2-phenylethyl]adenosine (R-PIA) and I-R; adenosine and I-R; and glibenclamide, IP, and I-R. Parameters of muscle function (postischemic maximal force, performance, contraction index, and force after 1 min of stimulation) were then assessed in vitro in the extensor digitorum longus muscle. RESULTS: Pretreatment with either IP or the K(ATP) channel opener cromakalim significantly improved postischemic muscle function. The protective effect of cromakalim was not seen when the K(ATP) channel blocker glibenclamide was added. Glibenclamide, however, did not block IP-induced protection. Pretreatment with the adenosine A(1) receptor agonist 8-(p-sulfophenyl)-theophyllin (8-SPT) or with adenosine did not improve postischemic muscle function. The adenosine receptor agonist did not block IP-induced protection against ischemic damage. CONCLUSIONS: The results show significant improvements in postischemic skeletal muscle function after IP or cromakalim pretreatment but they do not support a role for K(ATP) channels or for adenosine receptors in IP of skeletal muscle.


Asunto(s)
Precondicionamiento Isquémico , Músculo Esquelético/irrigación sanguínea , Animales , Presión Sanguínea , Temperatura Corporal , Frecuencia Cardíaca , Masculino , Músculo Esquelético/fisiología , Canales de Potasio/fisiología , Ratas , Ratas Wistar , Receptores Purinérgicos P1/fisiología
19.
Arch Orthop Trauma Surg ; 120(7-8): 426-31, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10968532

RESUMEN

Total knee joint transplantation has been performed in animal models and humans. This study investigates the impact of this operation on knee joint function in a dog model. Therefore, replantation was compared to transplantation during a 6-month follow-up period in four dogs in each group. The peak vertical ground reaction force normalized in all legs undergoing replantation and in two of four after transplantation. A third transplant recipient reduced loading from the 4th month due to a local complication, and the fourth succumbed to sepsis 3 months postoperatively. A weight-bearing index (WBI), defined as loading of the grafted divided by loading of both hind-limbs decreased from 0.48 +/- 0.08 preoperatively to 0.13 +/- 0.10 by 1 month after replantation and from 0.53 +/- 0.07 to 0 after transplantation. After 6 months, weight-bearing of all replant recipients was restored, but reduced in two transplant recipients with graft function. Full recovery after replantation, but impaired function after transplantation, was also reflected in the histological results: normal histological pictures of blood vessels, cartilage, bone and soft tissues were found in all replant recipients, but infiltrative vasculopathy indicating chronic rejection was found in the transplanted joints. The results of this animal study confirm that the procedure can lead to satisfactory functional results but also emphasize the need for perfect control of immunosuppression.


Asunto(s)
Articulaciones/trasplante , Locomoción/fisiología , Complicaciones Posoperatorias/fisiopatología , Rango del Movimiento Articular/fisiología , Soporte de Peso/fisiología , Animales , Fenómenos Biomecánicos , Ciclosporina/farmacología , Perros , Femenino , Rechazo de Injerto/patología , Rechazo de Injerto/fisiopatología , Articulaciones/patología , Articulación de la Rodilla/patología , Articulación de la Rodilla/fisiopatología , Masculino , Complicaciones Posoperatorias/patología
20.
Br J Cancer ; 83(2): 204-8, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10901371

RESUMEN

NY-ESO-1 gene encodes a novel member of the cancer/testis (CT) family of human tumour-associated antigens (TAA). Specific monoclonal antibodies (mAb) have identified the corresponding gene product in lysates of tumour cell lines as a 22 kDa protein but no data are available concerning its intracellular location or distribution within neoplastic tissues. We have generated NY-ESO-1 specific mAbs recognizing the target molecule in cytospin preparations and in sections from clinical tumour specimens. These reagents identify NY-ESO-1 TAA in melanoma cell lines expressing the specific gene as a cytoplasmic protein, sharing the intracellular location of most MAGE TAA. In a series of 12 melanoma specimens, specific staining, limited to neoplastic cells, was detectable in the five cases where NY-ESO-1 gene expression was observed. In two of them over 90% of tumour cells showed evidence of positive staining. Lower percentages of positive neoplastic cells ranging between single cells and 50% were observed in the remaining tumours. These data suggest that active specific immunotherapies targeting NY-ESO-1, alone or in combination with other TAA could be of high clinical relevance in sizeable subgroups of melanoma patients.


Asunto(s)
Anticuerpos Monoclonales , Antígenos de Neoplasias/análisis , Melanoma/metabolismo , Proteínas de la Membrana , Proteínas/análisis , Línea Celular , Humanos , Inmunohistoquímica , Proteínas/inmunología , Proteínas Recombinantes/inmunología , Células Tumorales Cultivadas
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