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1.
Colorectal Dis ; 22(11): 1734-1740, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32643856

RESUMEN

AIM: Laparoscopic Hartmann's reversal (HR) is a major abdominal operation that is associated with considerable morbidity and mortality. The robotic approach, with its intrinsic advantages, could potentially overcome the technical complexity of laparoscopy. The aim of this study was to evaluate the short-term results of a series of 24 robotic HR cases. METHOD: The data from 24 patients who underwent robotic HR between September 2016 and July 2019 at two different institutions were prospectively collected and retrospectively analysed. A full robotic single-docking reversal procedure with intracorporeal anastomosis was performed in all patients. RESULTS: The mean age and body mass index of the patients were 69 years and 26 kg/m2 , respectively. Of the patients, 58% were ≥ 70 years old and 42% had comorbidities (mean Charlson Comorbidity Index 3). The mean operating time was 240 min. There were no cases of conversion to the open or laparoscopic approach. No diverting loop ileostomies were constructed. The mean length of hospital stay was 6 days. Minor complications were recorded in three patients. Neither major complications nor 30-day readmissions were registered. CONCLUSIONS: Robotic HR is a feasible and safe procedure. The robotic approach has low rates of major complications and conversion and could potentially increase the number of patients undergoing HR.


Asunto(s)
Laparoscopía , Procedimientos Quirúrgicos Robotizados , Anastomosis Quirúrgica , Colostomía , Humanos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Resultado del Tratamiento
2.
Surg Endosc ; 34(2): 557-563, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31011862

RESUMEN

BACKGROUND: Laparoscopic right hemicolectomy is a commonly performed procedure. Little is known on how to perform the enterotomy closure after stapled side-to-side intracorporeal anastomosis. METHOD: A multicentric case-controlled study has been designed to compare different ways to fashion enterotomy closure: double layer versus single layer, sewn versus stapled, and robotic versus laparoscopic approach. Furthermore, additional characteristics including sutures' materials, interrupted versus running suture and the presence of deep corner suture has been investigated. RESULTS: We collected data for 1092 patients who underwent right hemicolectomy at ten centers. We analyzed 176 robotic against 916 laparoscopic anastomosis: no significant differences were found in terms of bleedings (p = 0.455) and anastomotic leak (p = 0.405). We collected data from 126 laparoscopic sewn single-layer versus 641 laparoscopic sewn double-layer anastomosis: a significant reduction was recorded in terms of leaks in double-layer group (p = 0.02). About double-layer characteristics, we found a significant reduction of bleedings (p = 0.008) and leaks (p = 0.017) with a running suture; similarly, a reduction of bleedings (p = 0.001) and leaks (p = 0.005) was observed with the usage of deep corner closure. The presence of a barbed suture thread seemed to significantly reduce both bleedings (p = 0.001) and leaks (p = 0.001). We found no significant differences in terms of bleedings (p = 0.245) and anastomotic leak (p = 0.660) comparing sewn versus stapled anastomosis. CONCLUSIONS: Fashioning a stapled ileocolic intracorporeal anastomosis, we can recommend the adoption of a double-layer enterotomy closure using a running barbed suture in the first layer. Totally, stapled closure and robotic assistance have to be considered a non-inferior alternative.


Asunto(s)
Anastomosis Quirúrgica , Colectomía/métodos , Colon Ascendente/cirugía , Neoplasias del Colon/cirugía , Íleon/cirugía , Técnicas de Sutura , Técnicas de Cierre de Heridas , Anciano , Fuga Anastomótica/cirugía , Estudios de Casos y Controles , Femenino , Humanos , Laparoscopía , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Procedimientos Quirúrgicos Robotizados , Grapado Quirúrgico
4.
Int J Dent Hyg ; 16(4): 553-558, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29797806

RESUMEN

OBJECTIVES: The aim of this study was to investigate the morphological and surface roughness changes in dental root samples following periodontal scaling by hand curette, piezoelectric ultrasonic devices or a combination of these. METHODS: Twenty-four monoradicular teeth extracted as a result of periodontal disease were divided into 4 groups: Group A was treated by piezoelectric ultrasonic scaler Piezon® Master 400; Group P by piezoelectric ultrasonic scaler PiezoSmart® ; Group C using Gracey curette 7/8; Group AC by a combined technique of piezoelectric ultrasonic scaler Piezon® Master 400 and Gracey curette 7/8. The treated samples were then analysed using a white light interferometer and scanning electron microscopy (SEM). RESULTS: Roughness analysis revealed major surface alterations in Group C (Sa  = 24.98 µm); the samples treated using the combined technique (Group AC) showed reduced but still significant alteration (Sa  = 14.48 µm), while samples treated with the piezoelectric ultrasonic devices (Group A and Group P) presented the lowest roughness values (Sa  = 8.99 and Sa  = 4.45 µm, respectively). A significant difference was found between groups C and P (P = 0.036). SEM analysis confirmed the roughness analysis revealing non-homogeneous surfaces in Group C, while a less morphological alteration was noted in the other groups. CONCLUSION: All periodontal devices used in this in vitro study produced a certain degree of surface alteration. Hand curettes appear to have a major impact on surface integrity compared with piezoelectric ultrasonic devices.


Asunto(s)
Cálculos Dentales/terapia , Raspado Dental/instrumentación , Ondas de Choque de Alta Energía , Curetaje Subgingival/instrumentación , Raíz del Diente/patología , Raíz del Diente/ultraestructura , Raspado Dental/métodos , Humanos , Microscopía Electrónica de Rastreo , Aplanamiento de la Raíz/instrumentación , Curetaje Subgingival/efectos adversos , Propiedades de Superficie
5.
Eur J Surg Oncol ; 43(11): 2060-2066, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28912072

RESUMEN

INTRODUCTION: Right-sided colon cancer has a worse prognosis than left-sided colon cancer. Complete mesocolic excision (CME) with central vessels ligation (CVL) reduces local recurrence, but is technically demanding, particularly with a laparoscopic approach. Aim of this study is to describe a new robotic approach to right colectomy with CME and CVL and to report oncologic safety and short term outcomes. METHODS: Twenty consecutive patients were included. All patients had a right colon adenocarcinoma and underwent right colectomy with a suprapubic approach. Surgery was realized with the Da Vinci Xi® system and all trocars were placed along a horizontal line 3-6 cm above the pubis. CME with CVL was realized in all the patients. Data analysed were: duration of surgery, conversions to open surgery, intraoperative and postoperative complication by Clavien Dindo classification, margins of resections, length of specimen and number of lymph nodes retrieved. RESULTS: Patients median age was 69 years, median body mass index was 27 kg/m2. Median operative time was 249 min, blood loss was negligible, no conversions to open or laparoscopic surgery occurred. Median hospital stay was six days; two postoperative grade IIIa Clavien-Dindo complications occurred, no 30-days postoperative death was registered. Resection margins were negative in all patients; median tumour diameter was 3.6 cm, median specimen length was 40 cm, median number of harvested lymph nodes was 40. CONCLUSIONS: Robotic right colectomy with CME using a suprapubic approach is a feasible and safe technique that allows for an extended lymphadenectomy and provides high quality surgical specimens.


Asunto(s)
Adenocarcinoma/cirugía , Colectomía/métodos , Neoplasias del Colon/cirugía , Procedimientos Quirúrgicos Robotizados , Anciano , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Tempo Operativo , Pronóstico , Resultado del Tratamiento
8.
Minerva Chir ; 70(5): 341-54, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26091139

RESUMEN

Dramatic improvements in the local recurrence rate of patients with rectal cancer have been observed after the introduction of the embriologically-based concept of total mesorectal excision by Heald more than 30 years ago. During the last decades, advances in multimodal treatment have further contributed to improve outcomes, but surgery still play a major role. Laparoscopic surgery for rectal cancer has been validated in randomized controlled trials to be oncologically as safe and effective as the open approach with better short-term postoperative outcomes. Nevertheless, laparoscopic low anterior resection continues to be challenging because of technical constraints and a steep learning curve. Robotic surgery may potentially offer significant advantages in rectal cancer surgery thanks to its technological features. This paper summarizes the current available evidence and highlights the most challenging aspects of robotic low anterior resection, with supporting data from the literature and from the authors' nearly ten-year experience in the field.


Asunto(s)
Colectomía , Laparoscopía , Neoplasias del Recto/cirugía , Procedimientos Quirúrgicos Robotizados , Colectomía/métodos , Medicina Basada en la Evidencia , Humanos , Laparoscopía/métodos , Metaanálisis como Asunto , Estudios Observacionales como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Neoplasias del Recto/mortalidad , Procedimientos Quirúrgicos Robotizados/métodos , Análisis de Supervivencia , Resultado del Tratamiento
9.
Obes Surg ; 25(10): 1822-32, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25835983

RESUMEN

BACKGROUND: The first global survey of bariatric/metabolic surgery based on data from the nations or national groupings of the International Federation for the Surgery of Obesity and Metabolic Diseases (IFSO) was published in 1998, followed by reports in 2003, 2009, 2011, and 2012. In this survey, we report a global overview of worldwide bariatric surgery in 2013. MATERIALS AND METHODS: A questionnaire evaluating the number and the type of bariatric procedure performed in 2013 was emailed to all members of bariatric societies belonging to IFSO. Trend analyses from 2003 to 2013 were also performed. RESULTS: There were 49/54 (90.7%) responders; 37 of the 49 with national registries. The total number of bariatric procedures performed worldwide in 2013 was 468,609, 95.7% carried out laparoscopically. The highest number (n = 154,276) was from the USA/Canada region. The most commonly performed procedure in the world was Roux-en-Y gastric bypass (RYGB), 45%; followed by sleeve gastrectomy (SG), 37%; and adjustable gastric banding (AGB), 10%. Most significant were the rise in prevalence of SG from 0 to 37% of the world total from 2003 to 2013, and the fall in AGB of 68% from its peak in 2008 to 2013. CONCLUSIONS: SG is currently the most frequently performed procedure in the USA/Canada and in the Asia/Pacific regions, and second to RYGB in the Europe and Latin/South America regions. The accuracy of the IFSO-based world survey of procedures would be enhanced if each nation or national group would create a national registry.


Asunto(s)
Cirugía Bariátrica , Obesidad Mórbida/epidemiología , Obesidad Mórbida/cirugía , Asia/epidemiología , Cirugía Bariátrica/efectos adversos , Cirugía Bariátrica/métodos , Cirugía Bariátrica/estadística & datos numéricos , Cirugía Bariátrica/tendencias , Canadá/epidemiología , Correo Electrónico , Europa (Continente)/epidemiología , Gastrectomía/efectos adversos , Gastrectomía/métodos , Gastrectomía/estadística & datos numéricos , Gastrectomía/tendencias , Derivación Gástrica/efectos adversos , Derivación Gástrica/métodos , Derivación Gástrica/estadística & datos numéricos , Derivación Gástrica/tendencias , Salud Global , Humanos , Laparoscopía/efectos adversos , Laparoscopía/métodos , Laparoscopía/estadística & datos numéricos , Laparoscopía/tendencias , América Latina/epidemiología , Prevalencia , Encuestas y Cuestionarios , Estados Unidos/epidemiología
10.
Minerva Chir ; 63(2): 93-9, 2008 Apr.
Artículo en Italiano | MEDLINE | ID: mdl-18427441

RESUMEN

AIM: Gastric cancer is the fifth most common cause of tumor-related death in Western countries. Surgery is the only effective treatment but only 50-60% of patients can receive a curative treatment because of absent or aspecific symptoms. The aim of this study was to develop a scale for gastric cancer patients that takes into account factors related to the tumor and to the patient. METHODS: Fifty-seven patients with gastric adenocarcinoma admitted to the Department of General, Geriatric Surgery and Diagnostic and Operative Endoscopy of the University ''Federico II'' in Naples, and treated by gastrectomy from January 1998 until December 2002, were included in this retrospective cohort. The prognostic score was created according to the variables identified in Cox analysis as statistically significant (P 0.1). RESULTS: The 5-year mortality rate was 61%. Cox analysis identified these variables with a significant effect on mortality: age ?60 (odds ratio (OR) 4.16; P=0.015), smoking or alcoholism (OR 2.66; P=0.057), pTNM I (OR 0.04; P=0.003), pTNM II (OR 0.18; P=0.029), pTNM III (OR 0.27; P=0.023), pTNM IV (OR 3.28; P=0.012), lymph node ratio (LNR) <20% (OR 0.15; P=0.01), LNR 20% (OR 3.83; P=0.002), Lauren diffuse histotype (OR 2.41; P=0.1) and location of the neoplasm at superior third (OR 6.70; P=0.003), middle third (OR 5.60; P=0.003), or inferior third (OR 0.32; P=0.008). Patients have been randomized into three groups according to their scores (3-40.5; 41-78.5; 79-115.5) and the 5-year mortality rate was 46%, 59%, 90% in group 1, 2 and 3 respectively. CONCLUSION: It is necessary to consider in prognostic stratification of gastric cancer patients not only pTNM staging but also other factors such as age, smoking or alcoholism, Lauren histotype, location and linfonodal involvement. It is possible to design a more effective prognostic score predicting the individual risk and addressing the therapy and the follow-up.


Asunto(s)
Adenocarcinoma/cirugía , Neoplasias Gástricas/cirugía , Adenocarcinoma/diagnóstico , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Alcoholismo/complicaciones , Estudios de Cohortes , Femenino , Gastrectomía , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Fumar/efectos adversos , Neoplasias Gástricas/diagnóstico , Análisis de Supervivencia
11.
Minerva Chir ; 62(3): 161-6, 2007 Jun.
Artículo en Italiano | MEDLINE | ID: mdl-17519840

RESUMEN

AIM: The aim of this study was to make a contribution to improve the care of patients with colorectal cancer by optimizing times and methods of the follow-up; particular attention is given to factors which may be important for the prognosis and for the quality of life in the immediate postoperative period. METHODS: The study includes all the patients with colorectal cancer who underwent laparotomic surgical treatment from 1996 to 2003. The total number of patients was 226 with an average age of 65 years; male to female ratio was 1.57:1. According to the stage of tumor, an adjuvant radiotherapeutic and/or chemiotherapeutic treatment was associated to surgery. RESULTS: On the basis of the preoperative staging and tumor localization, our patients underwent: 3 total colectomies, 57 right hemicolectomies, 137 left hemicolectomies, 6 Hartmann resections, 19 Miles resections, 4 transverse resections. CONCLUSION: The results obtained show that the 5-year overall survival is particularly influenced by the stage and the factors which directly or indirectly affect the primary tumor; thus the prognostic factors which should be considered for the survival and in the follow-up of these patients are: stage, grading and nodal involvement of the tumor.


Asunto(s)
Adenocarcinoma/mortalidad , Adenocarcinoma/cirugía , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/cirugía , Anciano , Femenino , Humanos , Masculino , Pronóstico , Tasa de Supervivencia , Factores de Tiempo
12.
Toxicol In Vitro ; 21(2): 197-203, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17070665

RESUMEN

In our previous studies, voacamine, a bisindolic alkaloid extracted from Peschiera fuchsiaefolia, was examined for its possible capability of enhancing the cytotoxic effect of doxorubicin (DOX) on multidrug resistant (MDR) human osteosarcoma cells (U-2 OS-R). Voacamine induced in resistant cells a significant increase of drug retention and intranuclear location which became comparable to those observed in the parental sensitive counterparts (U-2 OS-WT). In the present study, the cell survival analysis and the electron microscopic observations confirmed the evident cytotoxicity of DOX on MDR cells after pre-treatment with the plant extract. Moreover, an increase of the reactivity of P-glycoprotein (P-gp) with the monoclonal antibody UIC2, which recognizes an epitope of the drug transporter in its functional conformation, was revealed, demonstrating that voacamine is a substrate of P-gp, thus acting as a competitive antagonist of the cytotoxic agent. Moreover, to investigate if the enhancement of the cytotoxic effect induced by voacamine could be due to an apoptotic process, we carried out the analysis of cell morphology after Hoechst staining and the quantification of apoptosis by Annexin V-FITC assay. These evaluations showed a very low rate of apoptosis in U-2 OS-R cells treated with voacamine and DOX given in association. In addition, the combined treatment induced ultrastructural modifications suggestive of autophagic cell death. In particular, transmission electron microscopy observations revealed the presence of numerous lysosomes and the formation of a large number of autophagosomes containing residual digested material. In conclusion, these findings seem to indicate that voacamine is capable of enhancing the cytotoxic effect of DOX on MDR cells by favouring a lethal autophagic process.


Asunto(s)
Autofagia , Ibogaína/análogos & derivados , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/química , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Doxorrubicina/farmacología , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Humanos , Ibogaína/farmacología , Microscopía Electrónica de Rastreo , Osteosarcoma/tratamiento farmacológico , Osteosarcoma/patología , Conformación Proteica
13.
J Biomed Mater Res B Appl Biomater ; 65(1): 133-6, 2003 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-12632382

RESUMEN

The effects of perfluorohexyloctane (F6H8), recently investigated as a long-term artificial vitreous substitute, were studied in vitro, with the use of rat retinal cultures seeded on microporous inserts that allow the cell layer to be in contact with the material to be tested, on the apical side, and with the nutrient medium, on the basal side. After 72 h of treatment with F6H8, retinal cultures lost the characteristic two-layered organization with glial cells at the bottom and neuronal cells on top of them. They appeared to be composed of only one layer of polyhedrical, flattened, and disconnected cells. TUNEL assay revealed an evident increase in the percentage of apoptotic cells in F6H8-treated cultures (30.1 +/- 4.5), compared to control (10.3 +/- 2.6) and perfluoroctane-treated cultures (10.1 +/- 1.7). Immunolabeling of MAP-2, a protein of neuronal cytoskeleton, evidenced a marked loss of neurites. The results suggest that F6H8 is harmful to retinal cells in vitro and can therefore be potentially noxious to the retina as an artificial vitreous substitute.


Asunto(s)
Apoptosis/efectos de los fármacos , Comunicación Celular/efectos de los fármacos , Fluorocarburos/efectos adversos , Retina/citología , Animales , Materiales Biocompatibles/efectos adversos , Células Cultivadas , Embrión de Mamíferos , Ensayo de Materiales , Proteínas Asociadas a Microtúbulos/análisis , Neuritas/efectos de los fármacos , Ratas , Ratas Wistar , Retina/efectos de los fármacos
14.
Cornea ; 20(6): 647-50, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11473169

RESUMEN

PURPOSE: In 1979 Pintucci developed a biointegrable keratoprosthesis with polymethylmethacrylate optical cylinder integrated with a Dacron tissue-colonizable supporting element to avoid the complications caused by the interaction between the haptic element and the eye. The purpose of this article is to compare the colonization of three Dacron fabrics (thicknesses of 0.25 mm, 0.6 mm, and 1.4 mm) in vitro and in vivo to optimize the device performance. METHODS: In vitro three different Dacron fabrics were cultured for 3 days with 3.5 x 10(5) human fetal lung fibroblasts and observed with a scanning electron microscope. In vivo three different Dacron fabrics were implanted on the sclera near the superior rectus insertion in the right eye of six albino rabbits and were observed after 4 days with light and scanning electron microscopy. RESULTS: In the in vitro experiments, the cells were preserved and their structure was found to be normal. The 0.25-mm thick fabric was coated only on the surface, and the other fabrics were colonized in three dimensions. In the in vivo experiments, the 0.25-mm thick fabric appeared coated only on its surface. The other fabrics were three-dimensionally colonized and the Dacron filaments appeared embedded in neovascularized connective tissue with minimal foreign body reaction. The 1.4-mm thick colonized fabric showed a substantial loss of pliability. CONCLUSION: Given that the 0.25-mm thick fabric was coated only by connective tissue, that the 0.6-mm and 1.4-mm thick fabrics were perfectly colonized, and that the 1.4-mm thick fabrics showed a substantial loss of pliability, the 0.6-mm thick fabric haptic part of the Pintucci keratoprosthesis is preferred. For 19 years, the 0.6-mm Dacron fabric Pintucci keratoprosthesis was implanted in 159 eyes with good results, overcoming the apparently inseparable difficulties represented by mechanical anchorage and biointegrability of a keratoprosthesis.


Asunto(s)
Materiales Biocompatibles , Córnea , Fibroblastos/citología , Tereftalatos Polietilenos , Prótesis e Implantes , Animales , Células Cultivadas , Tejido Conectivo/ultraestructura , Feto , Humanos , Pulmón , Microscopía Electrónica de Rastreo , Implantación de Prótesis , Conejos , Esclerótica/cirugía
16.
Implant Dent ; 9(3): 219-25, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11307408

RESUMEN

The aim of the study was to evaluate the mechanical performance and the structure of neoformed bone around hydroxyapatite-coated titanium fixtures according to guided bone regeneration techniques. Ten hydroxyapatite-coated titanium fixtures were inserted in the femurs of five rabbits, in which a cortical defect was created and after the insertion of the fixture, covered with a resorbable membrane obtained from bovine Achilles tendon collagen Type I (A implant). In the same femur, a second fixture was inserted in similar cavities without application of the membrane (B implant). After 60 days, the animals were sacrificed, and block sections of the femoral bone containing the implants were embedded in polymethylmetacrylate and subjected to tensile shear-stress at break testing. After the detachment of the implants from the bone, their surfaces were examined with a scanning electron microscope. Tensile shear-stress values for A and B implant specimens were comparable to some extent, but the former had a lower performance. In this regard, scanning electron microscope observations showed that the neoformed cortical bone present cervically around implant A was much thicker than around implant B.


Asunto(s)
Regeneración Ósea , Colágeno , Fémur/cirugía , Regeneración Tisular Guiada Periodontal/instrumentación , Membranas Artificiales , Implantes Absorbibles , Animales , Materiales Biocompatibles , Bovinos , Materiales Biocompatibles Revestidos , Implantes Dentales , Durapatita , Femenino , Fémur/patología , Fémur/fisiopatología , Masculino , Microscopía Electrónica de Rastreo , Modelos Animales , Osteogénesis/fisiología , Adhesión en Plástico , Polimetil Metacrilato , Conejos , Estrés Mecánico , Propiedades de Superficie , Resistencia a la Tracción , Titanio
17.
J Biomed Mater Res ; 49(1): 53-7, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10559746

RESUMEN

The effect of a nonsteroidal antiinflammatory drug commercially available in eye drop form (sodium diclofenac) was assayed for its ability to affect biofilms formed by clinical Staphylococcus epidermidis isolates. Biofilms produced by one strain positive for a slime-associated antigen, suggested to be expressed by more virulent strains, was not affected by sodium diclofenac treatment. On the other hand, biofilm produced by the slime-positive, antigen-negative strain showed dramatic alterations already after short treatments with sodium diclofenac as reported for salicylate and other nonsteroidal drugs. Such results suggest further investigation of the possible use of sodium diclofenac drops in the treatment of ophthalmic infections in soft contact lens wearers.


Asunto(s)
Antibacterianos/farmacología , Biopelículas , Lentes de Contacto Hidrofílicos/microbiología , Diclofenaco/farmacología , Staphylococcus epidermidis/crecimiento & desarrollo , Antiinflamatorios no Esteroideos/farmacología , Antígenos Bacterianos/análisis , Adhesión Bacteriana/efectos de los fármacos , Microscopía Electrónica de Rastreo , Staphylococcus epidermidis/efectos de los fármacos
18.
Int J Dev Neurosci ; 16(5): 423-32, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9829178

RESUMEN

Pigment Epithelium-Derived Factor (PEDF), purified from human retinal pigment epithelial (RPE) cell culture medium, is a neurotrophic factor which potentiates the differentiation of human Y-79 retinoblastoma cells and increases the survival of cerebellar granule cells. To investigate the effects of PEDF on non-transformed retinal cells, we used primary cultures of neonatal albino rat retinas, where the three principal cell types of the retinal layers (neuronal, glial and epithelial) were all present and focussed our attention on RPE cells, which are of special relevance for retinal pathophysiology. PEDF had a dramatic effect on these cells. They showed a modified phenotype, with larger dimensions, higher cytoplasmic spreading, presence of phagocytic vacuoles, development of wide intercellular contacts, and increase and maturation of pigment granules. These results suggest that PEDF may have a role in regulating RPE cell differentiation.


Asunto(s)
Gránulos Citoplasmáticos/efectos de los fármacos , Proteínas del Ojo/farmacología , Factores de Crecimiento Nervioso/farmacología , Epitelio Pigmentado Ocular/efectos de los fármacos , Proteínas/farmacología , Retina/efectos de los fármacos , Serpinas/farmacología , Animales , Animales Recién Nacidos , Comunicación Autocrina , Adhesión Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Senescencia Celular/efectos de los fármacos , Humanos , Fenotipo , Epitelio Pigmentado Ocular/citología , Ratas , Ratas Wistar , Retina/citología
19.
J Biomed Mater Res ; 41(4): 608-13, 1998 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-9697034

RESUMEN

Perfluorodecalin (PFD), a high specific weight, water-immiscible perfluorocarbon, previously studied as a potential blood substitute, now is used widely in the field of ophthalmic surgery as a tool for maneuvering intraocular tissues and as a short- or medium-term vitreous substitute. In in vivo experiments, several types of lesions in retinal tissue have been described in conjunction with long-term PFD treatment. To better evaluate the biological effects of PFD on retinal cells, we tested it on primary cultures of rat retina seeded on special cyclopore wells that allow the culture to be fed from the bottom side while the top side is in contact with the water-immiscible compound. We found that PFD changed the pattern of cell arrangement and induced loss of neurites. The modification of cell arrangement was less evident at the periphery of the wells where the amount of PFD, and consequently the pressure exerted, was lower. This observation suggests that the changes may be due more to a physical than to a toxic effect of PFD.


Asunto(s)
Materiales Biocompatibles , Fluorocarburos/farmacología , Neuritas/efectos de los fármacos , Retina/efectos de los fármacos , Animales , Animales Recién Nacidos , Células Cultivadas , Microscopía Electrónica de Rastreo , Neuritas/ultraestructura , Ratas , Ratas Wistar , Retina/citología , Retina/ultraestructura
20.
J Biomed Mater Res ; 41(2): 211-20, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9638525

RESUMEN

Hyaluronan [hyaluronic acid (HA)] has been implicated in various cellular processes such as proliferation, adhesion, migration, and differentiation. The secondary and tertiary structures of HA give it very important and unique viscoelastic properties. HA-composed materials are currently used intraocularly during ophthalmological surgery to facilitate surgical procedures and prevent tissue damage. To examine the effects of three viscous biomaterials composed of hyaluronan (Healon, IAL, and Biolon) used in ophthalmological surgery, the membrane electrical properties of the erythroleukemic K562 cell line exposed to these materials were investigated. Membrane conductivity, membrane permittivity, and the conductivity of the cytosol were evaluated using dielectric relaxation measurements in the radiofrequency range and fitting the experimental results to the general equations of the Maxwell-Wagner effect. The results demonstrate that while membrane permittivity and the conductivity of the cytosol are not significantly altered, the membrane conductivity of K562 cells exposed to all three biomaterials increases substantially and in a time-dependent manner with respect to untreated cells. These observations seem to indicate that hyaluronan perturbs ionic transport while it does not vary the type, quantity, or distribution of membrane components. In addition, the variations induced by these substances on the cell membrane are not dependent upon the molecular weight or on the biological origin of hyaluronan. These results may aid in elucidating the mechanisms involved in hyaluronan/cell membrane interaction and thus may provide a deeper understanding of the complications related to their use in ophthalmological surgery.


Asunto(s)
Membrana Celular/efectos de los fármacos , Ácido Hialurónico/farmacología , Membrana Celular/fisiología , Tamaño de la Célula , Citosol/efectos de los fármacos , Citosol/fisiología , Elasticidad , Conductividad Eléctrica , Humanos , Transporte Iónico/efectos de los fármacos , Leucemia Eritroblástica Aguda/patología , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Lubrificación , Potenciales de la Membrana/efectos de los fármacos , Peso Molecular , Factores de Tiempo , Células Tumorales Cultivadas , Viscosidad
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