BMP-2 and titanium particles synergistically activate osteoclast formation

A previous study showed that BMP-2 (bone morphogenetic protein-2) and wear debris can separately support osteoclast formation induced by the receptor activator of NF-κB ligand (RANKL). However, the effect of BMP-2 on wear debris-induced osteoclast formation is unclear. In this study, we show that neither titanium particles nor BMP-2 can induce osteoclast formation in RAW 264.7 mouse leukemic monocyte macrophage cells but that BMP-2 synergizes with titanium particles to enhance osteoclast formation in the presence of RANKL, and that at a low concentration, BMP-2 has an optimal effect to stimulate the size and number of multinuclear osteoclasts, expression of osteoclast genes, and resorption area. Our data also clarify that the effects caused by the increase in BMP-2 on phosphorylated SMAD levels such as c-Fos expression increased throughout the early stages of osteoclastogenesis. BMP-2 and titanium particles stimulate the expression of p-JNK, p-P38, p-IkB, and P50 compared with the titanium group. These data suggested that BMP-2 may be a crucial factor in titanium particle-mediated osteoclast formation.

Influência do exercício na indução da apoptose e necrose das células do líquido sinovial de eqüinos atletas / Exercise induced apoptosis and necrosis in the synovial fluid cells of athletic horses

Examinaram-se os efeitos do estresse mecânico na resposta inflamatória e adaptativa dos tecidos articulares de cavalos atletas. O líquido sinovial foi colhido das articulações metacarpofalangeanas de eqüinos atletas antes, 3, 6 e 24 horas após o exercício, assim como de um grupo controle (cavalos não exercitados). A porcentagem de apoptose/necrose, o TNF-a e a PGE2 foram determinados pelo ensaio de AnexinaV/Iodeto de Propídeo, bioensaio (L929) e ELISA, respectivamente. Os resultados mostraram que a contagem total de células nucleadas foi sempre menor no grupo controle em relação ao grupo atleta (P<0,05). Observaram-se aumentos na porcentagem de células em apoptose (P<0,05) e necrose (P<0,05), concentração de PGE2 (P<0,05) e proteína sinovial (P<0,05), e diminuição da concentração de TNF-a (P<0,05) após 3 horas do término do exercício. O grupo atleta apresentou grau moderado de inflamação articular após o exercício intenso. Esta resposta dos tecidos articulares frente ao insulto mecânico do exercício, com maior intensidade às 3 horas após término da atividade esportiva e retornando à normalidade 24 horas após, revela a capacidade da adaptação articular ao estresse físico, em eqüinos atletas.

The effects of biomechanical stress on inflammatory and adaptative responses of articular tissues in athletic horses were investigated. Synovial fluid was collected from the metacarpophalangeal joints of athletic horses before exercise and 3, 6, 24 hours after exercise, and as well as from the control group (without exercise). Apoptosis/necrosis percentage, TNF-a and PGE2 were determined by annexin V/PI assay, bioassay (L929) and ELISA, respectively. The results showed that total leukocyte count was higher in the athletic group when is compared with the control group. Three hours after the exercise was done there were increases of cellular apoptosis (P>0.05) and necrosis (P<0.05) percentage, PGE2 concentration (P<0.05) and protein concentration (P<0.05), and the TNF-a level has dropped. The athletic group showed moderate level of joint inflammation after the strenuous exercise. This articular tissue response to biomechanical insult due to the exercise, with high intensity after 3 hours after training associated with normality after 24 hours, reveals the articular adaptation to physical stress in athletic horses.

Detection of circulant tumor necrosis factor-alpha, soluble tumor necrosis factor p75 and interferon-gamma in Brazilian patients with dengue fever and dengue hemorrhagic fever

Pro-inflammatory cytokines are believed to play an important role in the pathogenesis of dengue infection. This study reports cytokine levels in a total of 54 patients examined in Recife, State of Pernambuco, Brazil. Five out of eight patients who had hemorrhagic manifestations presented tumor necrosis factor-alpha (TNF-alpha) levels in sera which were statistically higher than those recorded for controls. In contrast, only one out of 16 patients with mild manifestations had elevated TNF-alpha levels. The levels of interleukin-6 (IL), IL-1beta tested in 24 samples and IL-12 in 30 samples were not significantly increased. Interferon-g was present in 10 out of 30 patients with dengue. The data support the concept that the increased level of TNF-alpha is related to the severity of the disease. Soluble TNF receptor p75 was found in most patients but it is unlikely to be related to severity since it was found with an equivalent frequency and levels in 15 patients with dengue fever and another 15 with dengue hemorrhagic fever

Respuesta inmune contra lipoproteínas de baja densidad modificadas en pacientes con diabetes mellitus no-insulino dependiente / Immune response against modified low density lipoproteins in patients with non insulin dependent diabetes mellitus

LDLs obtainded from blood of healthy subjects, were glycated or altered with malondialbehyde and used as antigens. Serum autoantibodies against these LDLs were measured by ELISA in 22 patients with non insulin dependent diabetes mellitus aged 46 to 67 years old and 13 healthy controls aged 41 to 64 years old. Basal and LDL stimulated tumor necrosis factor production in vitro, by peripheral leukocytes of diabetics and controls was also measured. Results: The ratio of glycated LDL/native LDL antibodies was higher in diabetics than in controls (9.37 ñ 2.72 and 0.41 ñ 0.11 respectively p < 0.05) and the ratio of MDA modified LDL/native LDL antibodies was not significantly different (8.64 ñ 3.83 and 2.14 ñ 1.26 respectively, NS). Tumor necrosis or production by leukocytes was higher in diabetics than in controls in basal conditions (53.3 ñ 15.3 and 26.9 ñ 14.7 arbitrary units (a.u.) respectively), when stimulated withnative LDL (46.5 ñ 5 and 24.3 ñ 9.4 a.u. respectively), when stimulated with malondialdehyde modified LDL (50 ñ 16.2 and 24.4 ñ 7.7 a.u. respectively) or when stimulated with glycated LDL (38.3 ñ 8.8 and 14.4 ñ 7.5 a.u. respectively). Conclusions: Diabetic patients have an enhanced immune response against low density lipoproteins, factor that could contribute to the accelared atherogenesis of this disease

Evaluación del factor de necrosis tumoral en tuberculosis

El factor de necrosis tumoral (TNF) es una citoquina que juega un papel muy importante en la patogénesis de la tuberculosis. Como un producto de monocitos-macrófagos y de linfocitos, puede ejercer efectos benéficos y perjudiciales como resultado de la infección con M. tuberculosis. En este estudio se implementaron y optimizaron las condiciones de un bioensayo con células L-929 para cuantificar TNF en un grupo de 14 pacientes tuberculosos y 15 controles sanos. Todos los pacientes fueron diagnosticados por baciloscopia y las muestras obtenidas antes de iniciar el tratamiento. En ambos grupos se realizó la prueba de tuberculina por el método de Mantoux, se obtuvieron células mononucleares de sangre periférica para efectuar ensayos de linfoproliferación y purificación de céluls adherentes. En los sobrenadantes obtenidos de los cultivos celulares se determinaron los niveles de TNF. Los experimento dosis-respuesta al PPD indicaron que 10 ug/ml era la dosis óptima a usar. Al comparar la liberación de TNF por células adherentes (monocitos) y células mononucleares completas (monocitos y linfocitos) encontramos que ambas poblaciones celulares producen TNF espontáneamente y en respuesta al PPD, con mayor liberación por parte de los monocitos. Con respecto a la producción de TNF y la respuesta proliferativa al PPD, se encontró correlación estadísticamente significativa entre estas dos variables (p=0,001). Nuestros hallazgos concuerdan con el modelo de respuesta Th1, en el cual se libera INF-gamma como respuesta inicial a la infección por la micobacteria, induciendo la posterior liberación de TNF con el propósito de controlar la infección.

Tumour necrosis factor alpha in stools as a marker in colonic diseases

This study was conducted on 40 patients with different inflammatory bowel diseases depending on the clinical examination, colonoscopic findings and histopthological reports. We aimed at measuring local stool TNF alpha and serum CRP in an attempt to explore their usefulness in assessing inflammatory bowel diseases. The patients were 10 colonic schistosomal patients [CS], 10 active ulcerative colitis [AUC], 10 cancer colon [CC], 5 irritable bowel syndrome [IBS], 3 inactive ulcerative colitis [lUC] and 2 with colonic diverticulosis [DV]. It was found that serum CRP in the different groups of patients were insignificantly different either from the control group or the IBS group. The TNF alpha level in the stool of patients with schistosomal polyposis, AUC and CC were significantly higher than the control group [P< 0.001]. From this data we concluded that serum CRP is of little value in the evaluation of inflammatory bowel diseases, while local TNF alpha may monitor disease activity and even low values exclude active inflammatory bowel diseases, cancer colon and polyposis of any aetiology

Purification and characterisation of tumour necrosis factor-alpha with cytotoxic activity against AK-5 cells.

Tumour necrosis factor (TNF) has been purified from the sera of animals in which the rat histiocytoma AK-5, was rejected spontaneously. Purified TNF-alpha is cytotoxic to AK-5 cells in vitro and the cytotoxic activity of TNF is completely neutralized by anti TNF antiserum. The circulating TNF levels are high by day 10 after the tumour transplantation. Animals which do not regress the tumour have very low levels of TNF in serum. Production of TNF by tumour regressing animals is part of the host immune response to the AK-5 tumour. Also, spleenomegaly in the animals which reject the AK-5 tumour is observed.