ABSTRACT
Gestational trophoblastic neoplasia (GTN) is the term to describe a set of malignant placental diseases, including invasive mole, choriocarcinoma, placental site trophoblastic tumor and epithelioid trophoblastic tumor. Both invasive mole and choriocarcinoma respond well to chemotherapy, and cure rates are greater than 90%. Since the advent of chemotherapy, low-risk GTN has been treated with a single agent, usually methotrexate or actinomycin D. Cases of high-risk GTN, however, should be treated with multiagent chemotherapy, and the regimen usually selected is EMA-CO, which combines etoposide, methotrexate, actinomycin D, cyclophosphamide and vincristine. This study reviews the literature about GTN to discuss current knowledge about its diagnosis and treatment.
Neoplasia trofoblástica gestacional (NTG) é o termo que descreve o conjunto de anomalias malignas da placenta, incluindo a mola invasora, coriocarcinoma, tumor trofoblástico do sítio placentário e tumor trofoblástico epitelióide. Ambos a mola invasora e o coriocarcinoma respondem bem à quimioterapia, com taxas de cura superiores a 90%. Desde o advento da quimioterapia, NTG de baixo risco tem sido tratada com monoquimioterapia, pelo geral methotrexate ou actinomicina-D. Casos de NTG de alto risco, contudo, devem ser tratados com poliquimioterapia, e o regime usualmente escolhido é o EMA-CO que combina etoposide, methotrexate, actinomicina-D, ciclofosfamida e vincristina. Esse estudo revê a literatura sobre NTG a fim de discutir os conhecimentos atuais sobre seu diagnóstico e tratamento.
Subject(s)
Animals , Male , Rats , Cathepsins/analysis , Cystatins/analysis , Cysteine Proteinase Inhibitors/metabolism , Endopeptidases , Leucine/analogs & derivatives , Osteoclasts/chemistry , Osteoclasts/enzymology , Salivary Proteins and Peptides/analysis , Bone Matrix/chemistry , Bone Matrix/enzymology , Cathepsin L , Cysteine Endopeptidases , Cathepsins/antagonists & inhibitors , Cathepsins/metabolism , Cystatins/metabolism , Cysteine Proteinase Inhibitors/toxicity , Leucine/metabolism , Leucine/toxicity , Lysosomes/enzymology , Microscopy, Immunoelectron , Osteoclasts/drug effects , Osteoclasts/ultrastructure , Rats, Wistar , Salivary CystatinsABSTRACT
Bone is a composite biomaterial, which is formed, when proteins constituting collagen fibers attract calcium, phosphate and hydroxide ions in solution to nucleate atop the fibers. It grows into a hard structure of tiny crystallites of hydroxyapatite, aligned along the long axis of collagen fibers. The present work reports the stimulating effect of static magnetic field on microstructure and mineralization process of bone repair. A unilateral transverse fracture of mid-shaft of metacarpal was surgically created in healthy goats under thiopental sedation and xylocaine analgesia. Two bar magnets (approximately 800 gauss/cm2 field strength) were placed across the fracture line at opposite pole alignment immobilized in Plaster of Paris (POP) splint bandage for static magnetic field stimulation. Radiographs were taken at weekly intervals up to 45 days. Results show that formation of extra-cellular matrix and its microstructure can be influenced by non-invasive physical stimulus (magnetic field) for achieving an enhanced osteogenesis, leading to quicker regeneration of bone tissue in goats. X-ray diffraction (XRD) patterns of treated (magnetic field-exposed) and control samples revealed the presence and orientation of crystalline structures. Intensity of diffraction peaks corresponding to 310 and 222 planes were enhanced with respect to 211 families of reflections, indicating preferential alignment of the crystals. Also, the percent crystallinity and crystal size were increased in treated samples. The study provides a biophysical basis for augmented fracture healing under the influence of semi-aligned static magnetic field applied across the fracture line.
Subject(s)
Animals , Bone Matrix/chemistry , Female , Fracture Healing , Goats , Magnetics/therapeutic use , Male , Microscopy, Electron , Microscopy, Electron, Scanning , Osteogenesis , X-Ray DiffractionABSTRACT
BACKGROUND: Bone morphogenetic proteins (BMPs) are also called growth and differentiation factors (GDFs) and form a subfamily of related proteins within the TGF-beta superfamily. BMP-4 is one ofmultifuntional growth factors with pleiotropic roles in many different cell types and is predominantly present in human bone tissue. OBJECTIVES: To analyze the content of extractable BMP-4 in human demineralized bone as a function of age. MATERIAL AND METHOD: Bone samples were ground and demineralized by exposure to 0.5 N HCl and then extracted by collagenase digestion. Extractable BMP-4 was analyzed using a commercially available enzyme-linked immunosorbent assay (ELISA). RESULTS: 63 samples of demineralized bone matrix (DBM) derived from 36 men and 27 women between the ages of 15-65 years. The extractable BMP-4 content appears to be age-dependent, with DBM from younger donors being most likely to have higher BMP-4 quantity. In addition, DBM with high osteoinductivity contained greater amounts of extractable BMP-4 than DBM samples with low osteoinductivity. CONCLUSION: The BMP-4 in demineralized bone undergoes age-related decrease that may contribute to the reduction of bone volume observed with aging.