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1.
Eur J Surg Oncol ; 46(8): 1415-1422, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32402509

RESUMO

OBJECTIVE: Aim of the manuscript is to discuss how to improve margins in sacral chordoma. BACKGROUND: Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery. METHODS: A multidisciplinary meeting of the "Chordoma Global Consensus Group" was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed. RESULTS: En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment. CONCLUSION: Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients.


Assuntos
Cordoma/radioterapia , Cordoma/cirurgia , Margens de Excisão , Sacro/cirurgia , Humanos , Terapia com Prótons/efeitos adversos , Dosagem Radioterapêutica
2.
Clin Radiol ; 74(9): 736.e13-736.e21, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31255248

RESUMO

AIM: To evaluate the accuracy of magnetic resonance imaging (MRI) and computed tomography (CT) in assessing the resection margins of primary malignant bone tumours. MATERIALS AND METHODS: Resected primary malignant bone tumour specimens removed from 46 patients (27 male; mean age: 48±22 years) were imaged using MRI (fat-saturated proton density-weighted and three-dimensional fat-suppressed T1-weighted gradient-recalled-echo) and CT immediately after surgery. A radiologist and an orthopaedist evaluated bone and soft-tissue margins of the specimens on both examinations. Histological evaluation was performed by a senior orthopaedic oncology pathologist. Margins were classified as R0 (safe margins), R1 (residuals between 0 and 1 mm), and R2 (macroscopic residuals). Cohen's k, chi-square, and McNemar's statistics were used. RESULTS: Having histology as the reference standard, reproducibility of the radiologist ranged from moderate (k=0.544) to substantial (k=0.741) for bone and soft-tissue margins on CT, respectively, while that of the orthopaedist ranged from fair (k=0.316) to moderate (k=0.548). When comparing R2 and R0+R1 scores, reproducibility of readers' evaluation of bone margins increased ranging from substantial (k=0.655) to perfect (k=1.000). Inter-reader agreement ranged from fair (k=0.308) to substantial (k=0.633). Accuracy of the radiologist and orthopaedist ranged from 76% to 83% and from 68% to 72%, respectively. When comparing R2 and R0+R1 scores, the accuracy of both readers ranged from 83% to 100%. There was no association between local recurrence and margin scores of histology, MRI, and CT (p≥0.058). CONCLUSIONS: MRI and CT may be useful for extemporaneous analysis of resection margins of primary malignant bone tumours, although wide accuracy variability between the different imaging methods was observed.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/patologia , Imageamento por Ressonância Magnética/métodos , Margens de Excisão , Tomografia Computadorizada por Raios X/métodos , Neoplasias Ósseas/cirurgia , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Neoplasia Residual/diagnóstico por imagem , Reprodutibilidade dos Testes
3.
J Biol Regul Homeost Agents ; 30(2): 399-408, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27358126

RESUMO

Despite the clinical importance of bone metastases, we still know little about their onset and progression and current diagnostic tools lack the sensitivity and specificity required for clear early diagnosis. We therefore need to continue studying the pathogenesis of bone metastatic invasion in order to improve diagnosis. The Wnt pathway has been described as having an important role in bone carcinogenesis and metastatic progression. This study investigated the diagnostic potential of the two main Wnt inhibitors, sclerostin and DKK-1, to improve the detection of osteolytic bone metastases. We measured sclerostin and DKK-1, MMP-2 and MMP-9, the bone resorption marker TRAP5b and the metastatic marker survivin in a control group of healthy patients, in patients with primary tumors and in a group with metastasis. Sclerostin and DKK-1 were clearly high in primary tumor patients and even higher in metastatic patients, compared to controls. The close correlations with metastatic markers and bone resorption markers make sclerostin and DKK-1 promising as new biomarkers in the diagnosis of bone osteolytic metastases.


Assuntos
Biomarcadores/sangue , Neoplasias Ósseas/secundário , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Osteólise , Proteínas/análise , Via de Sinalização Wnt/fisiologia , Adulto , Idoso , Neoplasias Ósseas/sangue , Feminino , Humanos , Masculino , Metaloproteinase 2 da Matriz/sangue , Metaloproteinase 9 da Matriz/sangue , Pessoa de Meia-Idade
4.
J Biol Regul Homeost Agents ; 30(4): 1203-1208, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28078875

RESUMO

Despite the clinical importance of metastasis to the skeleton, the diagnostic tools for early detection and monitoring of bone metastasis lack sensitivity and specificity. We evaluated a promising new serum biomarker, the soluble form of the Receptor of Advanced Glycosylated End-products (sRAGE). sRAGE is involved in the Wnt-signaling pathway, and has been reported to reduce the risk of cancer. We investigated the diagnostic potential of sRAGE to improve the detection and monitoring of bone metastasis. We measured sRAGE in the serum of control healthy subjects, patients with primary tumors and patients with bone metastasis. sRAGE was also correlated with the Wnt inhibitors DKK-1 and sclerostin, the bone resorption markers MMP-2, MMP-9 and TRAP5, and the metastatic marker survivin. sRAGE was significantly lower in primary tumor and metastatic patients than in healthy subjects. sRAGE also showed a strong negative correlation with DKK-1, sclerostin, MMP-2, MMP-9, TRAP5b and survivin. These results indicated that sRAGE might play a protective role in bone metastasis progression, and it may diagnostic significance for detecting and monitoring osteolytic metastases.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Ósseas/sangue , Receptor para Produtos Finais de Glicação Avançada/sangue , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/secundário , Feminino , Humanos , Imunoensaio , Masculino , Osteólise/sangue , Osteólise/diagnóstico , Osteólise/etiologia
5.
Oper Orthop Traumatol ; 24(3): 272-83, 2012 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-22743631

RESUMO

OBJECTIVE: Description of the surgical technique including approaches and spinal reconstruction principles for patients scheduled for multilevel en bloc excision of vertebral tumors (multisegmental total en bloc spondylectomy) with the aim to attain tumor-free margins and minimize the risk of local and systemic tumor recurrence. Restoration of biomechanically sufficient spinal stability. Functional preservation and/or regaining of adequate neurological function. INDICATIONS: Primary malignant and benign, aggressive spinal tumors. Solitary metastatic tumors of biologically and prognostically favorable primary tumor (good prognostic scores). Extracompartmental, multisegmental vertebral tumor manifestations according to Tomita type 6. CONTRAINDICATIONS: Diffuse spinal/vertebral tumor spread according to Tomita type 7 (disseminated spinal metastatic disease). Detection of distant metastases in the staging investigation. Biologically unfavorable tumor entities or primary systemic malignant tumors/diffuse disseminated malignoma (Tomita score < 4-5 points, Tokuhashi score < 12 points). SURGICAL TECHNIQUE: Depending on tumor growth, sequential performance of the anterior and posterior approach for local tumor release and preparation/replacement of encased large vessels. Posterior approach via dorsomedial incision and exposure of the posterior vertebral elements. Costotransversectomy, resection of the facets, resection of paravertebral rib segments. Laminectomy in the tumor-free lamina segment, resection of the ligamentum flavum and paradural ligation of affected nerve roots, bilateral ligation of the segmental arteries. Digital extrapleural palpation and dissection to the anterior vertebral body parts. Insertion of S-shaped spatulas ventral to the anterior aspect of the spine, and dissection of the disc spaces and the posterior longitudinal ligament. Instrumentation of pedicle screws and unilateral rod fixation, mobilization and careful, manual turning out/rotation of the affected vertebral segments around the longitudinal axis of the spinal cord. Interpositioning of a carbon-composite cage from posterior filled with autologous bone. Completion of the posterior stabilization, soft tissue closure, Goretex patch fixation if required in cases of chest wall resections. POSTOPERATIVE MANAGEMENT: Intensive care monitoring with balanced volume replacement/transfusion. Postoperative adjuvant radiotherapy or chemotherapy, depending on the protocol and resection margins.


Assuntos
Laminectomia/instrumentação , Laminectomia/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Fusão Vertebral/instrumentação , Fusão Vertebral/métodos , Neoplasias da Coluna Vertebral/cirurgia , Humanos , Estudos Retrospectivos , Resultado do Tratamento
6.
Eur Spine J ; 21 Suppl 1: S123-7, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22411038

RESUMO

PURPOSE: To assess the usefulness of magnetic resonance imaging (MRI) with spin-echo echo-planar diffusion-weighted imaging (SE-EPI-DWI) in differentiation between vertebral osteoporotic fractures and pathological neoplastic fractures. MATERIALS AND METHODS: Thirty-three patients with both osteoporotic or neoplastic vertebral fractures diagnosed with X-ray or TC were studied with MRI exam, (1.5 T unit) with DWI sequences. DWI sequences were qualitatively analyzed. Apparent diffusion coefficient (ADC) values were also determined and compared to the definitive histologic diagnosis. RESULTS: DWI of neoplastic lesions showed hyperintensity signal in 22 out of 23 cases. Mean ADC value of neoplastic fractures was 1.241 ± 0.4 × 10(-3) mm(2)/s; mean ADC value of osteoporotic fractures was 0.646 ± 0.368 × 10(-3) mm(2)/s. Neoplastic fractures showed ADC values significantly higher than osteoporotic ones (p < 0.001). DWI imaging and histology showed a significant correlation. CONCLUSION: DWI provides reliable information to support MRI diagnosis of neoplastic versus osteoporotic fractures. ADC value appears as a useful adjunctive parameter.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Fraturas por Osteoporose/diagnóstico , Fraturas da Coluna Vertebral/diagnóstico , Fraturas da Coluna Vertebral/etiologia , Neoplasias da Coluna Vertebral/complicações , Vértebras Torácicas/lesões , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/patologia , Estudos Retrospectivos , Sensibilidade e Especificidade , Fraturas da Coluna Vertebral/patologia , Vértebras Torácicas/patologia
7.
Eur Spine J ; 21(1): 1-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21818598

RESUMO

INTRODUCTION: The descriptions of total spondylectomy and further development of the technique for the treatment of vertebral sarcomas offered for the first time the opportunity to achieve oncologically sufficient resection margins, thereby improving local tumor control and overall survival. Today, single level en bloc spondylectomies are routinely performed and discussed in the literature while only few data are available for multi-level resections. However, due to the topographic vicinity of the spinal cord and large vessels, the multisegmental resections are technically demanding, represent major surgery and only few case reports are available. Surgical options are even more limited in cases of revision surgery and local recurrences when en bloc spondylectomy was considered to be not feasible due to high risk of vital complications in expanding resection margins. Deranged anatomy, implants in situ and extensive intra-/paraspinal scar tissue formation resulting from previously performed approaches and/or radiation are considered the principal complicating factors that usually hold back spine surgeons to perform revision for resection leaving the patient to palliative treatment. METHODS: We present two patient cases with previously performed piecemeal vertebrectomy in the thoracic spine due to a solitary high-grade spinal sarcoma. After extensive re-staging, both patients underwent a multi (4)-level en bloc spondylectomy in our department (one patient with combined en bloc lung resection). Except a local wound disturbance, there was no severe intra- or postoperative complication. RESULTS: After multilevel en bloc spondylectomy both patients showed a good functional outcome without neurological deficits, except those resulting from oncologically scheduled resection of thoracic nerve roots. After a median follow-up of 13 months, there was no local recurrence or distant metastasis. The reconstruction using a posterior screw rod system that is interconnected to an anterior vertebral body replacement with a carbon composite cage showed no implant failure or loosening. In summary, the approach of a multilevel en bloc surgery for revision and oncologically sufficient resection in cases of spinal sarcoma recurrences seems possible. However, interdisciplinary decision making in a tumor board, realistic evaluation of surgical resectability to attain tumor free margins, advanced experiences in spinal reconstructions and involvement of vascular, visceral and thoracic surgical expertise are essential preconditions for acceptable oncological and functional outcome.


Assuntos
Condrossarcoma/cirurgia , Vértebras Lombares/cirurgia , Recidiva Local de Neoplasia/cirurgia , Procedimentos Ortopédicos/métodos , Osteossarcoma/cirurgia , Neoplasias da Coluna Vertebral/cirurgia , Vértebras Torácicas/cirurgia , Condrossarcoma/diagnóstico por imagem , Condrossarcoma/patologia , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/prevenção & controle , Procedimentos Ortopédicos/instrumentação , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/patologia , Radiografia , Reoperação/instrumentação , Reoperação/métodos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/patologia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/patologia
8.
Recent Results Cancer Res ; 179: 141-67, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19230539

RESUMO

Primary malignant bone tumors of the vertebral column, i.e., bone sarcomas of the spine, are inherently rare entities. Vertebral osteosarcomas and chordomas represent the largest groups, followed by the incidence of chondro-, fibro-, and Ewing's sarcomas. Detailed clinical and neurological examination, complete radiographic imaging [radiographs, computed tomography (CT), magnetic resonance imaging (MRI)], and biopsy are the decisive diagnostic steps. Oncosurgical staging for spinal tumors can serve as a decision-guidance system for an individual's oncological and surgical treatment. Subsequent treatment decisions are part of an integrated, multimodal oncological concept. Surgical options comprise minimally invasive surgery, palliative stabilization procedures, and curative, wide excisions with complex reconstructions to attain wide or at least marginal resections. The most aggressive mode of surgical resection for primary vertebral column tumors is the total en bloc vertebrectomy, i.e., single- or multilevel en bloc spondylectomy. En bloc spondylectomy involves a posterior or combined anterior/posterior approach, followed by en bloc laminectomy, circumferential (360 degrees) vertebral dissection, and blunt ventral release of the large vessels, intervertebral discectomy and rotation/ en bloc removal of the vertebra along its longitudinal axis. Due to the complex interdisciplinary approach and the challenging surgical resection techniques involved, management of vertebral bone sarcomas is recommended to be performed in specific musculoskeletal tumor centers.


Assuntos
Sarcoma/patologia , Neoplasias da Coluna Vertebral/patologia , Humanos , Sarcoma/cirurgia , Neoplasias da Coluna Vertebral/cirurgia
9.
Eur Spine J ; 17(5): 715-25, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18196295

RESUMO

Wide surgical margins make en bloc spondylectomy and stabilization a referred treatment for certain tumoral lesions. With a total resection of a vertebra, the removal of the segment's stabilizing structures is complete and the instrumentation guidelines derived from a thoracolumbar corpectomy may not apply. The influence of one or two adjacent segment instrumentation, adjunct anterior plate stabilization and vertebral body replacement (VBR) designs on post-implantational stability was investigated in an in-vitro en bloc spondylectomy model. Biomechanical in-vitro testing was performed in a six degrees of freedom spine simulator using six human thoracolumbar spinal specimens with an age at death of 64 (+/- 20) years. Following en bloc spondylectomy eight stabilization techniques were performed using long and short posterior instrumentation, two VBR systems [(1) an expandable titanium cage; (2) a connected long carbon fiber reinforced composite VBR pedicle screw system)] and an adjunct anterior plate. Test-sequences were loaded with pure moments (+/- 7.5 Nm) in the three planes of motion. Intersegmental motion was measured between Th12 and L2, using an ultrasound based analysis system. In flexion/extension, long posterior fixations showed significantly less range of motion (ROM) than the short posterior fixations. In axial rotation and extension, the ROM of short posterior fixation was equivalent or higher when compared to the intact state. There were only small, nonsignificant ROM differences between the long carbon fiber VBR and the expandable system. Antero-lateral plating stabilized short posterior fixations, but did not markedly effect long construct stability. Following thoracolumbar en bloc spondylectomy, it is the posterior fixation of more than one adjacent segment that determines stability. In contrast, short posterior fixation does not sufficiently restore stability, even with an antero-lateral plate. Expandable verses nonexpandable VBR system design does not markedly affect stability.


Assuntos
Fixadores Internos , Vértebras Lombares/cirurgia , Vértebras Torácicas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Feminino , Fixação de Fratura/instrumentação , Fixação de Fratura/métodos , Humanos , Técnicas In Vitro , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Radiografia , Vértebras Torácicas/diagnóstico por imagem
10.
Clin Biomech (Bristol, Avon) ; 22(9): 957-64, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17854958

RESUMO

BACKGROUND: In selected cases, en-bloc spondylectomy is the only option to reach wide resection margins for patients with malignant tumours of the thoracolumbar spine. These patients must be also provided a secure initial stabilization of the spine and this is the role of vertebral body replacements employed with posterior fixation systems. The aim of this study was to determine the postimplantation stiffness of a connected vertebral body replacement pedicle screw system in different implantation scenarios following an en-bloc spondylectomy. Reconstruction was varied by posterior fixation lengths and axial compression forces during implantation. METHODS: Three-dimensional stiffness was assessed in 6 fresh frozen human spinal specimens (Th11-L3) using a six degree of freedom spine simulator. Following en-bloc spondylectomy reconstruction was performed using a carbon composite fibre vertebral body replacement connected to a posterior fixation system by two artificial pedicles. The spines were loaded with pure moments (7.5Nm) in the three main motion planes. The intersegmental rotations were measured between Th12 and L2. FINDINGS: Reconstructions using long posterior fixation modes demonstrated significant (P<0.05) higher stiffness compared to short posterior fixations in all motion planes. In axial rotation short posterior fixation modes failed to reach the values of the intact state. Neither high nor low axial compression force during implantation showed a significant impact on postfusional stiffness. INTERPRETATION: In this biomechanical model, the employed system should be implanted with a posterior fixation of two adjacent segments to the lesion in order to achieve a secure stabilization of the treated segment.


Assuntos
Fixação de Fratura/métodos , Laminectomia/métodos , Vértebras Lombares/fisiologia , Vértebras Lombares/cirurgia , Cirurgia Assistida por Computador/métodos , Vértebras Torácicas/fisiologia , Vértebras Torácicas/cirurgia , Simulação por Computador , Elasticidade , Feminino , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Amplitude de Movimento Articular , Estresse Mecânico
11.
Scand J Immunol ; 62 Suppl 1: 27-9, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15953179

RESUMO

The aim of this contribution is twofold: to honour Ivan Lefkovits with a short recollection of our scientific collaboration in the years 1972-1985 and a summary of our joint contribution to studies of the mechanisms and functions of the immune system and to acknowledge our long-lasting friendship. Ivan's limiting dilution microculture method was adapted to rabbit peripheral blood lymphocytes (PBL). The antibody produced in the responding cultures was shown to be electrophoretically homogeneous and, in rabbits heterozygous at the b locus, to express either one or the other allele. Thus, the antibody released in single microcultures was indeed the product of single B-cell clones and allelic exclusion, once achieved, was maintained throughout clonal proliferation. In the response to streptococcal polysaccharides, analysis of the clonotypes triggered in vitro provided information on mechanisms of clonal dominance. A two-stage culture system was established, where rabbit PBL were precultured at low cell density with antigen before being partitioned in limiting dilution cultures. This method provided a new tool for studies of various cellular aspects of the immune response. Moreover, it allowed the application of the limiting dilution analysis to PBL from unprimed animals. Later, the method was extended with success to human PBL, leading to studies of regulatory aspects of immunity in this species.


Assuntos
Células Produtoras de Anticorpos , Técnicas de Cultura de Células/história , Comportamento Cooperativo , Amigos , Comunicação Interdisciplinar , Animais , História do Século XX , Humanos , Coelhos
12.
Scand J Immunol ; 51(2): 164-7, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10722370

RESUMO

Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7: RGSDIAG), corresponding to a conserved sequence of human immunodeficiency virus (HIV) core protein p24 (amino acids 232- 238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood mononuclear cells (PBMC), probably acting at the level of monocytes. The Ch7 peptide displays sequence homology to human plasminogen. In the present report we show that a compound (6-aminoexanoic acid), known to prevent plasminogen binding to monocyte-like cells, greatly reduced the immunosuppressive capacity of Ch7. We suggest that the plasminogen receptor may represent a target structure on human monocytes for the immunosuppressive p24 sequence.


Assuntos
Proteína do Núcleo p24 do HIV/imunologia , Fragmentos de Peptídeos/imunologia , Receptores de Superfície Celular/metabolismo , Células Cultivadas , Proteína do Núcleo p24 do HIV/metabolismo , Humanos , Oligopeptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Receptores de Ativador de Plasminogênio Tipo Uroquinase
13.
J Med Microbiol ; 48(12): 1081-1086, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10591161

RESUMO

The role of specific antibodies in protective immunity to Bordetella pertussis has not yet been clearly defined. In the present work, the induction of a specific antibody response to B. pertussis in cultures of human peripheral blood mononuclear cells (PBMC) was investigated, on the assumption that the capacity of circulating lymphocytes to mount a specific response in vitro may provide a useful parameter for the evaluation of protective immunity. When PBMC from normal adult donors were cultured with a heat-inactivated B. pertussis whole-cell suspension, cells secreting antibodies to pertussis toxin, pertactin and filamentous haemagglutinin were generated consistently. The antibody response peaked between days 7 and 11 of culture and the antibodies produced were exclusively of the IgM class.


Assuntos
Anticorpos Antibacterianos/biossíntese , Antígenos de Bactérias/imunologia , Bordetella pertussis/imunologia , Leucócitos Mononucleares/imunologia , Adulto , Doadores de Sangue , Células Cultivadas , Humanos , Imunoglobulina M/biossíntese , Interleucina-2/imunologia , Leucócitos Mononucleares/microbiologia , Pessoa de Meia-Idade , Fatores de Tempo
14.
Scand J Immunol ; 48(3): 248-53, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9743208

RESUMO

Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7), corresponding to a conserved sequence of human immunodeficiency virus (HIV) core protein p24 (amino acids 232-238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood lymphocytes (PBL). Addition of recombinant human interferon-gamma (IFN-gamma) to Ch7-suppressed cultures restored the capacity to mount an antigen-specific antibody response, suggesting that a cytokine imbalance may be at the basis of the Ch7 immunosuppressive activity. In the present paper we show that the Ch7-dependent in vitro immunosuppression was accompanied by a significant up-regulation of prostaglandin E2 (PGE2) production and induction of interleukin-10 (IL-10)-secreting cells. In the presence of the PGE2 inhibitor indomethacin, IL-10 up-regulation was prevented and the induction of a specific antibody response was partially restored. PGE2 is indeed an important regulator of immune responses with the ability to differentially affect cytokine production. Thus, our results demonstrate that the Ch7 immunosuppressive epitope may primarily act by up-regulating PGE2 production and, through this mediator, by causing a cytokine dysregulation, finally responsible for immune response suppression.


Assuntos
Dinoprostona/biossíntese , Dinoprostona/fisiologia , Proteína do Núcleo p24 do HIV/efeitos dos fármacos , Imunossupressores/antagonistas & inibidores , Imunossupressores/farmacologia , Oligopeptídeos/antagonistas & inibidores , Oligopeptídeos/farmacologia , Formação de Anticorpos/efeitos dos fármacos , Células Produtoras de Anticorpos/química , Proteína do Núcleo p24 do HIV/farmacologia , Infecções por HIV/imunologia , Humanos , Indometacina/farmacologia , Interleucina-10/biossíntese , Interleucina-10/fisiologia , Regulação para Cima/efeitos dos fármacos
15.
J Clin Immunol ; 18(1): 39-47, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9475352

RESUMO

Intestinal mucosa represents an important portal of entry of HIV and a site of virus reservoir and active replication. Recently, in HIV patients, an early depletion of intestinal lamina propria T lymphocytes (LPT) has been described. HIV-1 gp120 has been demonstrated to promote apoptosis in noninfected isolated peripheral blood T cells, therefore we investigated whether gpl20 modulates apoptosis of normal human intestinal lamina propria T cells. Purified T cells were obtained by immunomagnetic negative selection from human lamina propria mononuclear cells isolated from surgical specimens by enzymatic procedure. Cells were incubated with or without recombinant gpl20 (10 microg/ml) and cultured either in the absence of any stimulus or in the presence of plate-bound anti-CD3 Ab (OKT3) or soluble anti-CD2 Ab (T11(2) + T11[3]). Apoptosis was assessed by flow cytometric analysis after propidium iodide staining. We demonstrated that preincubation of normal LPT cells with HIV-1 gpl20 accelerates the apoptosis observed during CD2-pathway stimulation of LPT cells. This process is mediated by Fas/Fas ligand interaction and related to an increased induction of Fas ligand mRNA by gpl20. Therefore HIV-1 gp120 could contribute to the depletion of noninfected LPT cells inducing a premature cell death.


Assuntos
Apoptose/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/química , Linfócitos T/imunologia , Receptor fas/imunologia , Apoptose/efeitos dos fármacos , Antígenos CD2/fisiologia , Antígenos CD4/farmacologia , Colo/imunologia , Proteína Ligante Fas , Proteína gp120 do Envelope de HIV/farmacologia , Humanos , Intestinos/citologia , Ligantes , Glicoproteínas de Membrana/farmacologia , Mucosa/imunologia , RNA Mensageiro/análise , Transdução de Sinais/imunologia , Transdução de Sinais/fisiologia , Linfócitos T/efeitos dos fármacos , Fatores de Tempo , Receptor fas/biossíntese , Receptor fas/genética
16.
Eur J Immunol ; 27(10): 2696-701, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9368628

RESUMO

The influence of interleukin-12 (IL-12) on the induction of a specific antibody response to the T-dependent antigen sheep erythrocytes (SRBC) in cultures of human blood lymphocytes was investigated. The response, evaluated as number of antigen-induced antibody-producing cells, was greatly increased in the presence of IL-12. When a two-stage limiting dilution culture system was used, the plot of the number of seeded cells versus the logarithm of the fraction of negative cultures deviated from linearity in antigen- and IL-12-stimulated cultures. However, linearity was reached when IL-2 was added in the second stage. Under these latter conditions, since single-hit criteria were fulfilled, it was possible to estimate the frequency of SRBC-specific B cell precursors able to respond to the antigen and to show that such frequency was increased upon addition of IL-12. Thus, the enhancing effect of IL-12 may be based on an increased frequency of responding precursor cells. The results here presented demonstrate, to our knowledge for the first time, a definite role of IL-12 in the induction of a specific antibody response in human cells. Further, they stress the importance for such studies of appropriate in vitro systems. Finally, they show that the induction of primary immune responses in cultures of human peripheral blood lymphocytes mostly depends on the proper cytokine balance at different time points.


Assuntos
Adjuvantes Imunológicos/farmacologia , Formação de Anticorpos/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Interleucina-12/farmacologia , Linfócitos B/imunologia , Células Cultivadas , Humanos , Projetos de Pesquisa
17.
Clin Exp Immunol ; 105(3): 403-8, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8809126

RESUMO

Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7), corresponding to a conserved sequence of HIV core protein p24 (aa 232-238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood lymphocytes (PBL). In the present study we show that Ch7 did not inhibit the induction of IFN-gamma-secreting cells nor the accumulation of IFN-gamma mRNA in antigen-stimulated cultures. However, delayed addition of recombinant human IFN-gamma to Ch7-suppressed cultures was able to restore fully the capacity to mount an antigen-specific antibody response. Thus, although the Ch7 immunosuppressive effect may not be directly related to a decreased production of IFN-gamma, an increased level of this cytokine is certainly able to counteract the negative effect of the peptide.


Assuntos
Proteína do Núcleo p24 do HIV/efeitos dos fármacos , Imunossupressores/antagonistas & inibidores , Imunossupressores/farmacologia , Interferon gama/farmacologia , Oligopeptídeos/antagonistas & inibidores , Oligopeptídeos/farmacologia , Anticorpos Monoclonais/biossíntese , Especificidade de Anticorpos , Células Cultivadas , Proteína do Núcleo p24 do HIV/farmacologia , Humanos , Interferon gama/biossíntese , Interferon gama/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos
18.
Cell Immunol ; 156(2): 286-95, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7517794

RESUMO

Ch7 (RGSDIAG), a synthetic heptapeptide derived from a conserved region of HIV p24 (aa 232-238), was previously shown to suppress antigen-induced responses in cultures of normal human peripheral blood lymphocytes (PBL). We show in this paper that Ch7 is the shortest peptide retaining full inhibitory capacity. Further, the peptide inhibited efficiently and in a dose-dependent manner the induction of a specific antibody response to the antigens SRC (sheep red cells) and Candida albicans but did not exert any effect on the induction of immunoglobulin-secreting cells in PWM-stimulated cultures. Finally, Ch7 inhibited anti-CD3-induced lymphoproliferation but did not affect anti-CD2 activation. These results suggest that a conserved epitope of HIV p24 may be able to prevent the induction of antigen-specific antibody responses by interfering with lymphocyte activation via the T3-Ti complex, resulting in the abrogation of immune functions that are defective in HIV-infected individuals.


Assuntos
Proteína do Núcleo p24 do HIV/imunologia , HIV-1/imunologia , Fragmentos de Peptídeos/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Diferenciação de Linfócitos T/metabolismo , Antígenos CD2 , Complexo CD3/metabolismo , Candida albicans/imunologia , Sequência Conservada , Regulação para Baixo , Epitopos/genética , Eritrócitos/imunologia , Proteína do Núcleo p24 do HIV/genética , Proteína do Núcleo p24 do HIV/farmacologia , HIV-1/genética , Humanos , Tolerância Imunológica , Técnicas In Vitro , Ativação Linfocitária , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/farmacologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores Imunológicos/metabolismo , Ovinos , Linfócitos T/imunologia
19.
Viral Immunol ; 7(4): 199-203, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7576034

RESUMO

The aim of this study was to assess the antibody reactivity in HIV-infected subjects against an HIV-1 p24 sequence, p226 (aa226-237), including a seven amino acid epitope showing immunosuppressive activity in vitro and to evaluate the relationship between anti-peptide antibody levels and disease progression. Sera of HIV-infected subjects, at different stages of disease, were compared to control sera in a retrospective evaluation. Recombinant HIV-1 p24 and p24- and control-peptides were used in an enzyme immunoassay as targets for antibodies present in the sera. Antibodies directed against the whole p24 protein and its peptides were found in all the sera studied but at different levels. The anti-p226 reactivity was not significantly different at different clinical stages. Nevertheless, it was inversely correlated to the reactivity directed against the whole protein, that was lower in subjects characterized by low CD4 cell numbers.


Assuntos
Anticorpos Anti-HIV/sangue , Proteína do Núcleo p24 do HIV/imunologia , Infecções por HIV/sangue , Imunossupressores/farmacologia , Sequência de Aminoácidos , Contagem de Linfócito CD4 , Anticorpos Anti-HIV/biossíntese , Proteína do Núcleo p24 do HIV/farmacologia , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , Ativação Linfocitária , Dados de Sequência Molecular
20.
Surg Radiol Anat ; 16(1): 87-91, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8047974

RESUMO

The ligaments of the ankle are superficial and easily accessible at ultrasonography. Surprisingly, the reliability of this technique has never been proven. With this goal in mind, ten ankles were subjected to a ultrasono-anatomic comparison. The five principle ligamentous fascicles (three on the lateral side and two on the medial side) measured at ultrasonography and the values verified after dissection. This study shows that the ligaments of the ankle are analyzed with ultrasonography and that the measures done are valid and have a precision of 2 mm for the anterior fascicle and the lateral fascicle of the lateral ligamentous plane Due to its simplicity and its low price, ultrasonography appears to be an important method in evaluating the ligaments and the degree of seriousness of ankle sprains.


Assuntos
Articulação do Tornozelo/anatomia & histologia , Articulação do Tornozelo/diagnóstico por imagem , Ligamentos Articulares/anatomia & histologia , Ligamentos Articulares/diagnóstico por imagem , Antropometria , Humanos , Ultrassonografia
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