RESUMO
Bacterial nanocellulose (BNC) is a promising biomedical material. However, the haemocompatibility (haemolysis and thrombogenicity) and acute and sub-chronic immune responses to three-dimensional (3D) BNC biomaterials have not been evaluated. Accordingly, this manuscript focused on the effect of 3D microporosity on BNC haemocompatibility and a comparison with 2D BNC architecture, followed by the evaluation of the immune response to 3D BNC. Blood ex vivo studies indicated that compared with other 2D and 3D BNC architectures, never-dried 2D BNC presented antihemolytic and antithrombogenic effects. Nevertheless, in vivo studies indicated that 3D BNC did not interfere with wound haemostasis and elicited a mild acute inflammatory response, not a foreign body or chronic inflammatory response. Moreover, compared with the polyethylene controls, the implant design with micropores ca. 60 µm in diameter showed a high level of collagen, neovascularization and low fibrosis. Cell/tissue infiltration increased to 91% after 12 weeks and was characterized by fibroblastic, capillary and extracellular matrix infiltration. Accordingly, 3D BNC biomaterials can be considered a potential implantable biomaterial for soft tissue augmentation or replacement.
Assuntos
Materiais Biocompatíveis/química , Celulose/química , Tecido Conjuntivo/cirurgia , Teste de Materiais/métodos , Nanoestruturas/química , Próteses e Implantes , Acetobacteraceae/química , Animais , Celulose/ultraestrutura , Tecido Conjuntivo/irrigação sanguínea , Tecido Conjuntivo/patologia , Hemólise , Humanos , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Varredura , Nanoestruturas/ultraestrutura , Tempo de Coagulação do Sangue TotalRESUMO
Bacterial nanocellulose (BNC) is a natural polymer composed of glucose units with an important application as a two and three-dimensional scaffold for tissue engineering. However, as a polysaccharide, BNC does not have the biological signals of protein biomaterials. Therefore, this paper aims to develop a novel methodology to biomimic soft extracellular matrix (ECM) chemistry on to 3D BNC using the bioengineering of fibroblasts (the cells responsible for producing and regenerating the ECM) to immobilise adhesion proteins such as collagen and fibronectin. Modified 3D BNC (Mod-BNC) biomaterials were morphologically, thermally, and chemically characterised, and furthermore, the cell response was analysed by adhesion studies using atomic force microscopy (AFM), XTT assay, and confocal microscopy. Cell-derived proteins were deposited on the BNC nanoribbon network to modify its surface. The contact angle was increased from 40° to 60°, reducing the wettability of the biomaterial, and during thermogravimetry, the proteins in Mod-BNC exhibited an enhanced thermal stability because of the interactions between themselves and BNC. Chemical and immunocytochemistry analyses confirmed the presence of collagen type I and fibronectin on 3D BNC. These proteins activate integrin adhesion pathways that generate stronger cell adhesions. AFM experiments showed higher forces and energies on modified biomaterials, and moreover, the cells that adhered on to Mod-BNC exhibited higher mitochondrial activity and higher cell populations per cubic millimetre than non-modified surfaces (NMod-BNC). Accordingly, it was established that this novel methodology is robust and able to biomimic the chemical surface of soft ECM and immobilise cell-derived adhesion proteins from fibroblast; moreover, the Mod-BNC exhibited better cell response than NMod-BNC because of the biological signals in 3D BNC.
Assuntos
Bactérias/química , Celulose/química , Nanopartículas/química , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis/química , Adesão Celular , Sobrevivência Celular , Camundongos , Células NIH 3T3 , Nanopartículas/ultraestrutura , Propriedades de Superfície , TermogravimetriaRESUMO
BACKGROUND: Tipe A aortic dissection involves the ascending aorta and has high mortality rates without surgical treatment. AIM: To report the results of surgical treatment of type A aortic dissection. MATERIAL AND METHODS: Retrospective review of medical records of 100 patients aged 17 to 78 years (73% males) operated between January 2000 and August 2008, for type A aortic dissection. Follow up was performed with telephone interviews and review of national death records. RESULTS: Eighty three percent of patients had an acute dissection. Operative mortality was 27 and 20% for patients with acute and chronic dissection, respectively. Mortality was 50% among patients aged 70 years or more, compared with 21% among their younger counterparts, The most common complication was bleeding that required a new surgical procedure in 18% of patients. Actuarial survival was 70% at five years. Cardiovascular problems caused the death of two of the nine patients that died during follow up. CONCLUSIONS: Surgical mortality among patients with type A aortic dissection was higher among patients with acute episodes and those aged 70 years or more.
Assuntos
Aneurisma Aórtico/cirurgia , Dissecção Aórtica/cirurgia , Doença Aguda , Adolescente , Idoso , Dissecção Aórtica/mortalidade , Aneurisma Aórtico/mortalidade , Feminino , Seguimentos , Hemorragia/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Adulto JovemRESUMO
Background: Tipe A aortic dissection involves the ascending aorta and has high mortality rates without surgical treatment. Aim: To report the results of surgical treatment of type A aortic dissection. Material and Methods: Retrospective review of medical records of 100 patients aged 17 to 78 years (73 percent males) operated between January 2000 and August 2008, for type A aortic dissection. Follow up was performed with telephone interviews and review of national death records. Results: Eighty three percent of patients had an acute dissection. Operative mortality was 27 and 20 percent for patients with acute and chronic dissection, respectively. Mortality was 50 percent among patients aged 70 years or more, compared with 21 percent among their younger counterparts, The most common complication was bleeding that required a new surgical procedure in 18 percent of patients. Actuarial survival was 70 percent at five years. Cardiovascular problems caused the death of two of the nine patients that died during follow up. Conclusions: Surgical mortality among patients with type A aortic dissection was higher among patients with acute episodes and those aged 70 years or more.
Assuntos
Adolescente , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Dissecção Aórtica/cirurgia , Aneurisma Aórtico/cirurgia , Doença Aguda , Dissecção Aórtica/mortalidade , Aneurisma Aórtico/mortalidade , Seguimentos , Hemorragia/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do TratamentoRESUMO
The Argentinian wheat cultivar Sinvalocho MA carries the Lr3 gene for leaf rust resistance on distal chromosome 6BL. In this cultivar, 33 spontaneous susceptible lines were isolated and cytogenetically characterized by C-banding. The analysis revealed deletions on chromosome 6BL in most lines. One line was nulli-6B, two lines were ditelo 6BS, two, three, and ten lines had long terminal deletions of 40, 30, and 20%, respectively, three lines showed very small terminal deletions, and one line had an intercalary deletion of 11%. Physical mapping of 55 amplified fragment length polymorphism (AFLP) markers detected differences between deletions and led to the division of 6BL into seven bins delimited by deletion breakpoints. The most distal bin, with a length smaller than 5% of 6BL, contained 22 AFLP markers and the Lr3 gene. Polymorphism for nine AFLPs between Sinvalocho MA and the rust leaf susceptible cultivar Gamma 6 was used to construct a linkage map of Lr3. This gene is at a genetic distance of 0.9 cM from a group of seven closely linked AFLPs. The location of the gene in a high recombinogenic region indicated a physical distance of approximately 1 Mb to the markers.
Assuntos
Mapeamento Cromossômico , Cromossomos de Plantas/genética , Genes de Plantas/genética , Doenças das Plantas/genética , Folhas de Planta/microbiologia , Polimorfismo Genético/genética , Triticum/genética , Bandeamento Cromossômico , Deleção Cromossômica , Ligação Genética , Marcadores Genéticos , Mapeamento Físico do Cromossomo , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Reação em Cadeia da Polimerase , Triticum/microbiologiaRESUMO
Background: Mechanical aortic valve replacement (AVR) results have been published extensively in industrialized countries. Aim: To assess our immediate and late results in patients subjected to AVR. Patients and Methods: We retrospectively studied 194 patients subjected to isolated AVR between 1995 and 2003. Mean age was 57 ± 13 years and 119 (61%) were male. One hundred thirty nine (73%) were in functional class III-IV, 20 (10%) had a previous cardiac operation and 25 (13%) were operated as an emergency. Surgical indication was stenosis in 110 (58%), regurgitation in 49 (26%) and stenosis/regurgitation in 31 (16%). Etiology was bicuspid valve 56 (29%), degenerative lesions 55 (28%), rheumatic valve disease 38 (20%) and endocarditis 27 (14%). Medtronic Hall was the most common prosthesis used in 157 patients (81%). Mean cardiopulmonary bypass time 97 ± 29 min and mean cross clamp time was 69 ± 21 min. Results: Operative mortality was 4.6% (3% in elective surgery, 16% in emergency surgery and 0% in reoperations). Follow-up was complete in 100% of cases, totalizing 636 patients-year. Survival was 91 ± 2%, 80 ± 4% and 73 ± 6%, at 1, 5 and 7 years, respectively. Multivariate risk analysis identified renal failure and endocarditis as predictors of early and late mortality. During follow up, the linear incidence rate for hemorrhage was 3.29% /patients-year, thromboembolism 2.04% patients-year and endocarditis 1.1% patients-year. Conclusions: AVR has low overall and elective mortality. Midterm survival is good but linear event rates related to anticoagulant treatment are higher than those previously published in industrialized countries. Renal failure and endocarditis were risk factors for early and late death.
Assuntos
Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valva Aórtica/cirurgia , Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca/mortalidade , Próteses Valvulares Cardíacas/normas , Complicações Pós-Operatórias/mortalidade , Chile/epidemiologia , Intervalo Livre de Doença , Seguimentos , Doenças das Valvas Cardíacas/mortalidade , Valva Mitral/cirurgia , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
La EPOC y la insuficiencia respiratoria crónica constituyen un importante problema de salud pública. Está demostrado que la oxigenoterapía domiciliaria a largo plazo mejora la sobrevida y calidad de vida de estos pacientes. Por ello el Instituto Nacional del Tórax organizó en 1984 el Programa de Oxigenoterapia Domiciliaria, con el trabajo de un equipo de profesionales y con una estructura operacionalmente eficiente. Hasta diciembre 2001 han ingresado al programa 560 pacientes, actualmente 112 de ellos están en el programa. El 67,9 por ciento tiene el diagnóstico de EPOC y el 72 por ciento presenta insuficiencia respiratoria global. En una cohorte de 118 pacientes estudiados a su ingreso y 1 año después no encontramos diferencias en la gasometría arterial ni en la espirometría. Si se observó una disminución del número de hospitalizaciones y días cama utilizadas por los pacientes. La calidad de vida evaluada en los primeros 50 pacientes demostró disminución de sintomas angustiosos y depresivos, como también de los elementos de deterioro psico-orgánico. El mayor problema del programa es la lista de espera por la alta demanda de la terapia y los limitados recursos financieros. La oxigenoterapia domiciliaria es un tratamiento efectivo que mejora tanto la sobrevida como la calidad de vida de los enfermos. Es un servicio absolutamente necesario para los pacientes respiratorios crónicos y por la magnitud del problema requeriría de un Programa Nacional de Oxigeno-terapia Domiciliaria
Assuntos
Humanos , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Pneumopatias Obstrutivas/terapia , Insuficiência Respiratória , Oxigenoterapia/métodos , Estudos de Coortes , Pneumopatias Obstrutivas/complicações , Qualidade de Vida , Insuficiência Respiratória , Serviços Hospitalares de Assistência Domiciliar/economia , Serviços Hospitalares de Assistência Domiciliar/organização & administração , EspirometriaRESUMO
Background: Home oxygen therapy is the only intervention that significantly prolongs survival of patients with chronic obstructive pulmonary disease. Since this therapy is expensive, it is imperative to calculate its cost-benefit ratio. Aim: To compare health care costs for patients in a home oxygen therapy program, with those of a similar group of patients in a waiting list for this therapy. Material and methods: A retrospective analysis of 21 patients on home oxygen therapy for 36 months or less and a group of 13 patients in the waiting list during a similar lapse. Medical consultations, drugs delivered and the cost of oxygen therapy were considered among ambulatory costs. Hospitalization costs included the number of days on regular or intermediary care beds, laboratory tests and drugs delivered. Results: The annual health care costs for patients on home oxygen therapy were 709,656 Chilean pesos and the costs for patients in the waiting list were 797,320 Chilean pesos. Conclusions: The overall health care costs of home oxygen therapy are similar to the costs required by patients with chronic obstructive pulmonary disease remaining in waiting lists
Assuntos
Masculino , Humanos , Feminino , Custos de Cuidados de Saúde/estatística & dados numéricos , Pneumopatias Obstrutivas/economia , Oxigenoterapia/economia , Listas de Espera , Serviços Hospitalares de Assistência Domiciliar/economiaRESUMO
La falla primaria es una complicación rara, pero de consecuencias importantes. Se define como la presencia de edema en el botón transplantado que persiste por más de 3 semanas a pesar del tratamiento máximo.El presente estudio se realizó para conocer la prevalencia de falla primaria en el servicio de Córnea y determinar las posibles causas. Se revisaron retrospectivamente 175 expedientes del servicio de córnea de la Asociación para Evitar la Ceguera en México, de los cuales 86 fueron incluidos, en el periodo comprendido de junio a agosto de 1998. Cuatro pacientes presentaron falla primaria (4.6 por ciento) y cuatro más presentaron edema estromal que mejoró después de 3 semanas por lo que se consideró que en este grupo de pacientes el edema observado fue atribuible a un endotelio parcialmente funcional que llevó a una compensación tardía.No hay datos concluyentes que puedan ser correlacionados con la falla primaria presentada, sin embargo tanto el promedio de edad y el intervalo de tiempo entre la muerte y la utilización del tejido es significativamente mayor en todo nuestro grupo de estudio, comparado con otros reportes.