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BACKGROUND: Retransplantation candidates are disadvantaged owing to lack of good-quality liver grafts. Strategies that can facilitate transplantation of suboptimal grafts into retransplant candidates require investigation. The aim was to determine whether late liver retransplantation can be performed safely with suboptimal grafts, following normothermic machine perfusion. METHODS: A prospectively enrolled group of patients who required liver retransplantation received a suboptimal graft preserved via normothermic machine perfusion. This group was compared with both historical and contemporaneous cohorts of patient who received grafts preserved by cold storage. The primary outcome was 6-month graft and patient survival. RESULTS: The normothermic machine perfusion group comprised 26 patients. The historical (cold storage 1) and contemporaneous (cold storage 2) groups comprised 31 and 25 patients respectively. The 6-month graft survival rate did not differ between groups (cold storage 1, 27 of 31, cold storage 2, 22 of 25; normothermic machine perfusion, 22 of 26; P = 0.934). This was despite the normothermic machine perfusion group having significantly more steatotic grafts (8 of 31, 7 of 25, and 14 of 26 respectively; P = 0.006) and grafts previously declined by at least one other transplant centre (5 of 31, 9 of 25, and 21 of 26; P < 0.001). CONCLUSION: In liver retransplantation, normothermic machine perfusion can safely expand graft options without compromising short-term outcomes.
Liver transplantation is a life-saving procedure for many different diseases. In the UK, one in 10 patients awaiting transplant have had a previous liver transplant. These retransplant operations are complex, and the general belief is that a good-quality donor liver graft is required for best outcomes. However, there is a significant shortage of good-quality organs for liver transplantation, so many patients awaiting retransplantation spend longer on the waiting list. This study investigated whether a new technology, called normothermic machine perfusion, could be used to preserve lower-quality donor livers and have successful outcomes for patients undergoing retransplantation. Traditionally, good-quality livers are preserved in an ice box and the study compared the outcomes of these two different approaches. The aim was to prove that normothermic machine perfusion improves access to transplantation for this group of patients, without compromising outcomes. A group of patients who underwent retransplantation and received a lesser-quality liver preserved with normothermic machine perfusion was compared with two groups of patients who had received a transplant with traditional ice-box preservation. The complications, graft, and patient survival of the former group was compared with those in the latter two groups who underwent liver retransplantation with better-quality liver grafts. The rate of survival and adverse surgical outcomes were comparable between the groups of patients who received a liver preserved via traditional ice-box preservation, and those who received a lesser-quality liver preserved via normothermic machine perfusion. Normothermic machine perfusion can potentially expand the number of suitable donor livers available for retransplant candidates.
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Trasplante de Hígado , Supervivencia de Injerto , Humanos , Hígado , Preservación de Órganos , PerfusiónRESUMEN
Background: New chemotherapeutic strategies for locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC) have been shown to improve survival in randomized clinical trials. Little is known about the use of such chemotherapies and their benefit in community-based hospitals. This retrospective study analyzes the overall survival of these patients under "real life conditions" before and after the introduction of FOLFIRINOX in 2011. Methods: We retrospectively identified consecutive patients with PDAC who were treated at our hospital from 2011 to June 2014 (2011+ cohort) and 2004 to 2010 (historical cohort). Patients were included if PDAC was diagnosed in a locally advanced or metastatic state and at least 1 cycle of chemotherapy was given. Survival was assessed until April 2016. Patients with FOLFIRINOX were further analyzed regarding drug administration and side effects. Results: 128 patients met the inclusion criteria. Of the 74 patients in the historical cohort, 62 patients received Gemcitabine. Of the 54 patients diagnosed between 2011 and June 2014, 28 patients received FOLFIRINOX and 22 Gemcitabine as the first-line chemotherapy. Only 34â% of the patients in the historical cohort received a second-line chemotherapy in comparison to 69â% in the 2011+ cohort. Median overall survival (OS) showed a survival of 13.1 months (95â% CI; 11.6â-â14.5) for the 2011+ cohort compared to 9.6 months (95â% CI; 6.1â-â13.1) in the historical group. Conclusion: This study shows a marked improvement in survival of patients diagnosed with locally advanced or metastatic PDAC in a community-based hospital during the past 4 years. The most likely reasons are the use of new polychemotherapies like FOLFIRINOX and the use of second-line chemotherapy.
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Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/secundario , Desoxicitidina/análogos & derivados , Hospitales Comunitarios/estadística & datos numéricos , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Camptotecina/administración & dosificación , Camptotecina/análogos & derivados , Carcinoma Ductal Pancreático/mortalidad , Desoxicitidina/administración & dosificación , Femenino , Fluorouracilo/administración & dosificación , Alemania/epidemiología , Humanos , Irinotecán , Leucovorina/administración & dosificación , Metástasis Linfática , Masculino , Persona de Mediana Edad , Compuestos Organoplatinos/administración & dosificación , Oxaliplatino , Neoplasias Pancreáticas/patología , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , GemcitabinaRESUMEN
Physical stress is common in GI endoscopists, leading to musculoskeletal disorders. Considering the increasing complexity of interventional GI endoscopy with prolonged examination time, work-related musculoskeletal disorders have come into focus. However, data on work-related health stress in German endoscopists are elusive. The aim of this study was therefore to investigate the prevalence and consequences of work-related musculoskeletal disorders in German endoscopists. A 24-item questionnaire on endoscopy-associated musculoskeletal disorders and standardized pain assessment was developed by an interdisciplinary team of endoscopists and sports medics. The survey was distributed online by the leading German societies for gastroenterology and endoscopy. Overall, 151 German practicing endoscopists took part in the study. Regarding the average number of endoscopic procedures per week, the study collective consisted mainly of high-volume endoscopists. The survey showed that most participants suffered from general musculoskeletal disorders (82.8%) and from work-related musculoskeletal disorders (76.8%). The most affected body parts were the neck, low back, thumb, and shoulder. Temporary absence from work due to symptoms was reported by 9.9% of the respondents. Over 30% of participating endoscopists stated the need for analgesics or physiotherapy due to musculoskeletal disorders. Age, professional experience and work time were identified as relevant risk factors for musculoskeletal health issues. A high number of German endoscopists are affected by musculoskeletal disorders due to specific working postures and repetitive movements with a large impact on personal health. Further interventional studies are mandatory to improve the risk prevention of endoscopic activity.
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Enfermedades Musculoesqueléticas , Enfermedades Profesionales , Endoscopía Gastrointestinal/efectos adversos , Alemania/epidemiología , Humanos , Enfermedades Musculoesqueléticas/epidemiología , Enfermedades Musculoesqueléticas/etiología , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/etiología , Enfermedades Profesionales/prevención & control , Prevalencia , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
Primary nonfunction (PNF) in the early postoperative period following liver transplantation is fatal if not managed appropriately with early retransplantation. Severe early allograft dysfunction can mimic PNF. The identification of treatable causative factors such as sepsis, hepatic artery, or portal vein thrombosis is essential to distinguish it from PNF, and their early management may avoid the need for retransplantation. In this article, we describe a case of sepsis-induced severe liver dysfunction from a contaminated graft perfused with normothermic machine perfusion (NMP), which presented in a manner similar to PNF. The implications of graft contamination are poorly described. To our knowledge, this is the first report of bacterial contamination of a graft that underwent NMP and subsequently caused severe sepsis in the recipient. The conditions created with NMP may be optimal for certain micro-organisms to thrive. The role of the liver in the immune system is complex as it provides an essential barrier to enterically derived portal venous pathogens and produces numerous acute phase proteins that augment the systemic immune response. Additionally, the liver is also known to restrain harmful and excessive systemic immune responses such as those that occur with the sepsis syndrome. The relationship between bacterial graft contamination, sepsis, and graft dysfunction may be multidirectional.
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Contaminación de Medicamentos , Trasplante de Hígado/efectos adversos , Soluciones Preservantes de Órganos/efectos adversos , Preservación de Órganos/efectos adversos , Complicaciones Posoperatorias/etiología , Sepsis/etiología , Femenino , Humanos , Persona de Mediana Edad , Perfusión , Donantes de TejidosRESUMEN
The effects of glucagon, adrenalin or rapamycin on glycogen autophagy in the liver and heart of newborn rats were studied using biochemical determinations and electron microscopy. Glucagon or adrenalin increased autophagic activity in the hepatocytes and myocardiocytes, glycogen-hydrolyzing acid glucosidase activity in the liver and heart and degradation of glycogen inside the autophagic vacuoles. Glucagon or adrenalin also increased the maltose-hydrolyzing acid glucosidase activity in the liver, but not in the heart. Similar effects were produced in the newborn heart by rapamycin. These observations support previous studies suggesting that the cellular machinery which controls glycogen autophagy in the liver and heart of newborn animals, is regulated by the cyclic AMP and the mTOR pathways.
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Autofagia/efectos de los fármacos , Glucógeno/metabolismo , Hígado/metabolismo , Miocardio/metabolismo , Animales , Animales Recién Nacidos , Epinefrina/farmacología , Femenino , Glucagón/farmacología , Corazón/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/ultraestructura , Hígado/efectos de los fármacos , Glucógeno Hepático/metabolismo , Microscopía Electrónica , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/ultraestructura , Embarazo , Ratas , Ratas Wistar , Sirolimus/farmacologíaRESUMEN
BACKGROUND: Cardiac allograft vasculopathy is a frequent sequel to cardiac transplantation, but the role of cytokines on the subsequent development of vasculopathy is still largely unknown. METHODS: We retrospectively studied 172 heart transplant recipients to investigate the relationship between the development of vasculopathy and various factors including the presence of transforming growth factor (TGF-beta) in the graft. Endomyocardial biopsy specimens were stained with antibodies for TGF-beta and CD+68, and a TGF-beta staining score was derived. Vasculopathy was diagnosed by angiography and rejection was graded according to the International Society of Heart and Lung Transplantation classification. TGF-beta(1) genotype was determined by polymerase chain reaction analysis of DNA. RESULTS: After a mean follow-up period of 68 +/- 32 months, the prevalence of significant vasculopathy was 52%. The TGF-beta staining score was higher in patients with more severe vasculopathy (95% confidence interval = 8.9-12.1) than in those who showed minimal or mild vasculopathy score changes of more than 7 (95% confidence interval = 3.4-5.1), P =.0001. TGF-beta expression correlated with the degree of vasculopathy (r = 0.73, P <.0007) during the study period. Risks for vasculopathy were recipient homozygous TGF-beta genotype, recurrent rejection, recipient history of ischemic heart disease, donor male sex, old donor age (years), and donor history of subarachnoid hemorrhage. CONCLUSION: A strong association exists between the expression of TGF-beta in cardiac biopsy specimens and the development of vasculopathy. TGF-beta in the cardiac allograft is related to its genotype and to the number of rejection episodes. Strategies to down-regulate TGF-beta production might improve the outcome of cardiac allografts.
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Enfermedad Coronaria/etiología , Trasplante de Corazón/efectos adversos , Factor de Crecimiento Transformador beta/análisis , Adulto , Biopsia con Aguja , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/metabolismo , Endocardio/patología , Femenino , Genotipo , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Estudios Retrospectivos , Factores de Riesgo , Factor de Crecimiento Transformador beta/genéticaRESUMEN
OBJECTIVE: The aim of this study was to compare the medium-term results of right heart pressures, tricuspid valve dysfunction, overall cardiac performance, and survival between the bicaval and standard techniques. METHOD: Between 1991 and 1997, 201 heart transplantations were performed in our center. Right heart catheterization was performed up to 12 months after transplantation. Echocardiography was used to assess left ventricular and tricuspid valve function. RESULT: The standard technique was used in 105 cases, and the bicaval technique was used in 96 cases. There was no difference in the age, preoperative parameters, pulmonary hemodynamics, or ischemic time between the 2 groups. Right atrial pressure (4.3 +/- 4.0 mm Hg for the bicaval vs 10.9 +/- 4.8 mm Hg for standard technique) and mean pulmonary artery pressure (17.5 +/- 5.3 mm Hg and 22.5 +/- 5.2 mm Hg, respectively) were lower for the bicaval recipients up to 12 months after the operation (P =.001 and. 01, respectively). Left ventricular ejection fraction was higher for the recipients of the bicaval technique up to the most recent measurement (P =.005). The prevalence of moderate or severe tricuspid regurgitation was higher in the recipients of the standard technique up to the most recent measurement (28% vs 7%; P =.02). The actuarial survival at 1, 3, and 5 years was 74%, 70%, and 62% for the recipients of the standard technique versus 87%, 82%, and 81% for the recipients of the bicaval technique (P <.03, <.04, and <.02, respectively). CONCLUSION: The bicaval technique maintains good left ventricular function, lower incidence and severity of tricuspid valve dysfunction, and improved survival compared with the standard technique.
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Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón/métodos , Análisis Actuarial , Anciano , Biopsia , Presión Sanguínea , Cateterismo Cardíaco , Causas de Muerte , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Trasplante de Corazón/efectos adversos , Trasplante de Corazón/mortalidad , Trasplante de Corazón/tendencias , Humanos , Masculino , Persona de Mediana Edad , Volumen Sistólico , Análisis de Supervivencia , Resultado del Tratamiento , Insuficiencia de la Válvula Tricúspide/etiología , Insuficiencia de la Válvula Tricúspide/fisiopatología , Función Ventricular IzquierdaRESUMEN
Surface layers of sulphated glycosaminoglycan can be quantified by X-ray microanalysis using the local mass-fraction of the element sulphur. As a calibration standard radiolabelled chondroitin sulphate has been attached covalently to a nylon surface at various densities to the point where the molecules are packed as close as the radius of gyration permits.
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Sulfatos de Condroitina , Condroitín , Endotelio Vascular , Modelos Biológicos , Acetilación , Condroitín/análogos & derivados , Microanálisis por Sonda Electrónica , Microscopía Electrónica , Nylons , TritioRESUMEN
The effects of propranolol on the glycogen autophagy in newborn rat hepatocytes were studied by using biochemical determinations, electron microscopy and morphometric analysis. Propranolol lowered the liver cyclic AMP and cyclic AMP-dependent protein kinase activity. It also decreased the formyl-methionyl-leucyl-phenylalanine (FMLP)-inhibitable Ca2+-ATPase activity including lysosomal calcium uptake pump. The normal postnatal increase in the volume of autophagic vacuoles and the activity of acid glycogen-hydrolyzing alpha glucosidase were inhibited. Also, the degradation of glycogen inside the autophagic vacuoles was apparently inhibited. The activity of acid mannose 6-phosphatase was increased. These findings indicate that propranolol influences several steps in the sequence of events leading to the breakdown of glycogen in the autophagic vacuoles of newborn rat hepatocytes. This supports our previous studies suggesting that cyclic AMP regulates glycogen autophagy.
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Glucógeno/metabolismo , Hepatocitos/metabolismo , Propranolol/farmacología , Adenosina Trifosfatasas/metabolismo , Antagonistas Adrenérgicos beta/farmacología , Animales , Animales Recién Nacidos , Autofagia , Fenómenos Bioquímicos , Bioquímica , Células Cultivadas , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Inmunohistoquímica , Hígado/metabolismo , Microscopía Electrónica , Monoéster Fosfórico Hidrolasas/metabolismo , Ratas , Factores de Tiempo , alfa-Glucosidasas/metabolismoRESUMEN
The effects of agents that could manipulate the lysosomal calcium such as phorbol myristate acetate, ionophore A23187, and phentolamine on the lysosomal glycogen degradation were studied by electron microscopy, morphometric analysis, and biochemical assays in newborn rat hepatocytes. Phorbol myristate acetate, which promotes the input of calcium to lysosomes, increased the total volume of autophagic vacuoles and the activity of lysosomal glycogen-hydrolyzing acid alpha 1,4 glucosidase and decreased the fractional volume of undigested glycogen inside the autophagic vacuoles and also decreased the activity of acid mannose 6-phosphatase. Ionophore A23187, which releases lysosomal calcium, produced opposite results in these enzyme activities. Phentolamine, an alpha-adrenergic blocking agent which interferes with the generation of phosphoinositides and may activate the lysosomal calcium uptake pump, increased the total volume of autophagic vacuoles and the activity of lysosomal glycogen-hydrolyzing acid glucosidase and decreased the fractional volume of undigested glycogen inside the autophagic vacuoles. The results of this study constitute evidence that changes in lysosomal calcium may influence certain aspects of autophagy, including the degradation of glycogen inside the autophagic vacuoles. They also support our previous postulate [Kalamidas and Kotoulas (2000a,b) Histol Histopathol 15:29-35, 1011-1018] that stimulation of autophagic mechanisms in newborn rat hepatocytes may be associated with acid mannose 6-phosphatase activity-deficient lysosomes.
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Autofagia/efectos de los fármacos , Calcimicina/farmacología , Glucógeno/metabolismo , Ionóforos/farmacología , Fentolamina/farmacología , Acetato de Tetradecanoilforbol/farmacología , Animales , Animales Recién Nacidos , Calcimicina/administración & dosificación , Células Cultivadas , AMP Cíclico/administración & dosificación , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/ultraestructura , Ionóforos/administración & dosificación , Hígado/citología , Lisosomas/metabolismo , Microscopía Electrónica , Fentolamina/administración & dosificación , Ratas , Ratas WistarRESUMEN
The effects of rapamycin on glycogen autophagy in the newborn rat liver were studied using biochemical determinations, electron microscopy, and morphometric analysis. Rapamycin increased the fractional volume of hepatocytic autophagic vacuoles, the liver lysosomal glycogen-hydrolyzing activity of acid glucosidase, the degradation of glycogen inside the autophagic vacuoles, and decreased the activity of acid mannose 6-phosphatase. These findings suggest that rapamycin, a known inhibitor of the mammalian target of rapamycin (mTOR) signaling, induces glycogen autophagy in the newborn rat hepatocytes. mTOR may participate in the regulation of this process.
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Autofagia/efectos de los fármacos , Inmunosupresores/farmacología , Glucógeno Hepático/metabolismo , Hígado/efectos de los fármacos , Sirolimus/farmacología , Animales , Animales Recién Nacidos , Hígado/metabolismo , Hígado/ultraestructura , Microscopía Electrónica , RatasRESUMEN
Electronmicroscopy was used to observe morphological changes of the Pseudomonas aeruginosa PA0 bacteriophage F116 when treated with various biocides commonly used as antibacterial and antifungal agents. Because of its large size (145 nm) and its organised structure (an isometric head and a tail), it was possible to classify structural damage into eight categories. The morphological changes induced depended on the type of biocide used and its concentration. Glutaraldehyde increased the number of phages with empty heads. Peracetic acid and phenol altered the appearance of the viral genome packaged inside the head, produced fractured heads, and damaged the tail. Peracetic acid also induced folding of the phage heads. The alcohols tested also altered the head structure. Cetylpyridinium chloride induced mainly fractured head damage. Chlorhexidine had little effect on the structure of F116.
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Desinfectantes/farmacología , Fagos Pseudomonas/efectos de los fármacos , 1-Propanol/farmacología , Cetilpiridinio/farmacología , Clorhexidina/farmacología , Etanol/farmacología , Glutaral/farmacología , Microscopía Electrónica , Ácido Peracético/farmacología , Fenol , Fenoles/farmacología , Fagos Pseudomonas/ultraestructura , Pseudomonas aeruginosa/virologíaRESUMEN
Cells of mupirocin-sensitive, moderately-resistant and highly-resistant cultures of Staphylococcus aureus (mupirocin MICs 0.13, 16 and > 512 mg/l, respectively) were exposed to various concentrations of the antibiotic and examined by transmission electron microscopy. The most severe damage occurred in mupirocin-sensitive cells. Cells from moderately-resistant cultures trained in vitro to high-level mupirocin resistance were more hydrophobic than the parent cells. The antibiotic was slowly lethal to the mupirocin-sensitive strain and sub-inhibitory concentrations prevented or reduced growth of the other strains over a 6 h incubation period, irrespective of whether the drug was added at zero time or in the exponential growth phase.
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Antibacterianos/farmacología , Mupirocina/farmacología , Staphylococcus aureus/efectos de los fármacos , Farmacorresistencia Microbiana , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica , Staphylococcus aureus/ultraestructuraRESUMEN
Salmonella typhimurium was inoculated onto 1 g cubed samples of irradiated, raw, skinless chicken breast, which were then incubated at 30 degrees C under humid conditions. Kinetic growth data was obtained by means of viable counts performed on triplicate samples over a 24 h period. In addition, the spatial arrangement of cells on samples taken 6, 12 and 24 h after inoculation was observed by scanning electron microscopy. The population entered exponential growth approximately 3 h after inoculation, and maintained a constant rate of growth for approximately 13 h before entering a stationary phase. A generation time of 0.74 h was recorded. Scanning electron microscopy observations revealed colonial development from loose clusters of cells at 6 h to discrete, compact microcolonies (approximately 40 microns in diameter) by 12 h. By 24 h colonies were well-developed (approximately 600-700 microns in diameter) with a well-defined colony periphery. The results of this study give insight into the growth and development of bacteria on meat tissue, and serve to highlight that the nature of such growth is quite different from that in dispersed liquid culture systems, i.e. those traditionally used to model such growth.
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Irradiación de Alimentos , Carne/microbiología , Salmonella typhimurium/crecimiento & desarrollo , Animales , Pollos , Concentración de Iones de Hidrógeno , TemperaturaRESUMEN
Trypsin-releasable glycosaminoglycans from the luminal surface of intact pig aorta were measured following metabolic labelling with [35S]sulphate. Chondroitin sulphate was found to be present at a surface density equal to that already established for heparan sulphate (5 X 10(11) chains per cm2). This result was confirmed by X-ray microanalysis of the luminal sulphur content before and after treatment with specific glycosaminoglycan-degrading enzymes. This result implies that approximately half of the luminal surface is occupied by sulphated glycosaminoglycans.
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Sulfatos de Condroitina/análisis , Condroitín/análogos & derivados , Endotelio Vascular/análisis , Animales , Aorta Torácica/análisis , Microanálisis por Sonda Electrónica , Femenino , Masculino , Papaína , Sulfatos/análisis , Radioisótopos de Azufre/análisis , Porcinos , TripsinaRESUMEN
Rat alveolar type II cells were isolated following elastase digestion and cultured on polycarbonate filters at various densities and in different media. Two days after seeding, the cells formed a monolayer on the filters which consisted predominantly of type II cells, these then de-differentiated to a alveolar type I-like cell monolayer by day 6. The seeding density and media utilized affected the transepithelial electrical resistance (TEER) generated by the monolayer. Only certain culture conditions allowed the production of a monolayer that mimics, putatively, the in vivo alveolar epithelium (TEER greater than 1000 omega cm2). Vmax and K(m) values for the uptake of putrescine by monolayers exhibiting low and high TEERs on day 6 were determined. The capacity of the putrescine uptake mechanisms was greater in cell monolayers exhibiting a high TEER than those exhibiting a low TEER, suggesting that the TEER does not only measure the "tightness" of the monolayer but contains an element representative of the viability of the cell monolayer. The selection of appropriate TEERs for cell culture investigations is discussed.
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Alveolos Pulmonares/metabolismo , Putrescina/metabolismo , Transporte Biológico , Recuento de Células , Permeabilidad de la Membrana Celular , Células Cultivadas/química , Células Cultivadas/metabolismo , Medios de Cultivo , Impedancia Eléctrica , Epitelio/metabolismo , Manitol/metabolismo , Alveolos Pulmonares/química , Alveolos Pulmonares/ultraestructuraRESUMEN
Culture of the developing dental tissues has contributed to understanding of developmental processes during early odontogenesis. However, to understand fully the mechanisms involved during dentinogenesis and tissue repair there is a need to develop culture models for the dentine-pulp complex from more mature dental tissues. This study describes the development of a system for the organ culture of mature rodent teeth. Slices of incisors from 28-day-old rats were embedded in a semisolid, agar-based medium and cultured on floating Millipore filters at the liquid-gas interface for up to 14 days. Preservation of cell and tissue morphology was observed throughout the entire dentine-pulp complex after each culture period and autoradiographic studies showed that the odontoblasts were actively synthesizing and secreting extracellular matrix during culture. Transmission electron microscopy confirmed that the phenotypic morphology of the odontoblasts had been maintained during culture. These results demonstrate that the dentine-pulp complex from mature rodent tissues can be cultured successfully for substantial periods of time and will provide a useful model for the study of dentinogenesis and tissue repair.
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Pulpa Dental/citología , Dentina/citología , Dentinogénesis , Animales , Supervivencia Celular , Masculino , Microscopía Electrónica , Modelos Biológicos , Odontoblastos/ultraestructura , Técnicas de Cultivo de Órganos , Ratas , Ratas WistarRESUMEN
The localization of acid mannose 6-phosphatase activity in newborn rat hepatocytes was demonstrated at the electron microscopic level by using a histochemical method based on the work of Robinson and Karnovsky. Reaction product was virtually restricted to the lysosomes. Most of them exhibited various grades of reactivity. Some were devoid of activity. Our observations suggested that this histochemical method could be used to differentiate distinct subpopulations of lysosomes on the basis of their acid mannose 6-phosphatase activity.