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1.
J Neurochem ; 157(6): 1850-1860, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33078390

RESUMO

Pituitary adenylate cyclase-activating peptide (PACAP) receptor (PAC1R) is a class B Gprotein-coupled receptor (GPCR) that is widely expressed in the human body and is involved in neuronal differentiation. As class B GPCRs are known to form heterocomplexes with family members, we hypothesized that PAC1R mediates neuronal differentiation through interaction with a class B GPCR. We used the BRET assay to identify potential interactions between PAC1R and 11 class B GPCRs. Gastric inhibitory polypeptide receptor (GIPR) and secretin receptor were identified as putative binding partners of PAC1R. The effect of heterocomplex formation by PAC1R on receptor activation was evaluated with the cyclic (c)AMP, luciferase reporter, and calcium signaling assays; and the effects on receptor internalization and subcellular localization were examined by confocal microscopy. The results suggested he PAC1R/GIPR heterocomplex suppressed signaling events downstream of PAC1R, including cAMP production, serum response element and calcium signaling, and ß-arrestin recruitment. Protein-protein interaction was analyzed in silico, and induction of neuronal differentiation by the PAC1R heterocomplex was assessed in SH-SY5Y neuronal cells by measure the morphological changes and marker genes expression by real-time quantitative PCR and western blot. Over-expression of GIPR suppressed PACAP/PAC1R-mediated neuronal differentiation and the differentiation markers expression in SH-SY5Y cells. GIPR regulates neuronal differentiation through heterocomplex formation with PAC1R.


Assuntos
Diferenciação Celular/fisiologia , Neurônios/metabolismo , Receptores dos Hormônios Gastrointestinais/química , Receptores dos Hormônios Gastrointestinais/metabolismo , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/química , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Sequência de Aminoácidos , Animais , Células CHO , Linhagem Celular Tumoral , Cricetinae , Cricetulus , Células HEK293 , Humanos , Ligação Proteica/fisiologia , Estrutura Secundária de Proteína , Receptores dos Hormônios Gastrointestinais/genética , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/genética
2.
Int J Phytoremediation ; 22(10): 1028-1037, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32062984

RESUMO

This work evaluated the use of Dialium guineense seed waste (DGS) and its sodium hydroxide modified form (NH-DGS) as biosorbent for ciprofloxacin (CPF) from synthetic solution as well as the desorption potentials. Central composite design (CCD) was applied for optimization of the alkaline treated biosorbent by response surface methodology using design expert. Both biosorbents were characterized by FTIR, SEM, EDX, and BET analysis. The CCD showed NaOH concentration of 0.46 M and temperature of 96 °C to be effective for optimized modification of NH-DGS. Optimum removal of CPF was obtained at pH 6.0, contact time 120 min, temperature 300 K, and dosage of 0.1 g. The Freundlich model gave the best fit compared to the other isotherms tested with R2 values >0.97951. NH-DGS exhibited a maximum uptake capacity of 120.34 mg/g higher than some reported adsorbents for CPF. The pseudo-second-order model was suitable in the fitting of the kinetic data. A non-spontaneous process was obtained for CPF biosorption on DGS which became spontaneous after alkaline treatment. Over 84% desorption of CPF was achieved on both biosorbents using 0.3 M HCl which envisaged the use of NH-DGS as an efficient material for treatment of waters contaminated with CPF.


Assuntos
Ciprofloxacina , Poluentes Químicos da Água/análise , Adsorção , Biodegradação Ambiental , Concentração de Íons de Hidrogênio , Cinética , Pós , Sementes , Termodinâmica
3.
Environ Monit Assess ; 187(2): 14, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25619697

RESUMO

The Ogba River in southern Nigeria is an important water resource for its riparian communities. This study evaluates impact of anthropogenic influences on the Ogba River using water chemistry and macroinvertebrate data sets obtained over a period of 6 months between January and June 2012. Four stations, stations 1-4, characterised by various human activities were chosen along the river. Organic wastes from domestic and industrial sources were the major point sources of pollutants. Station 2 where the municipal wastewater drains into the river had elevated values of flow velocity, BOD5, sulphate, phosphate, nitrate and sodium. Based on the canonical correspondence analysis (CCA), 5-day biochemical oxygen demand (BOD5), sulphate, nitrate and phosphate were the main factors that help to shape the macroinvertebrate assemblage structure of the Ogba River. Macroinvertebrates clustered strongly by stations than by seasons indicating that water quality differences between the stations were responsible for the observed differences in the biotic assemblage. The preponderance of naidid oligochaetes, baetid nymphs and certain tolerant dipteran taxa including chironomids and ceratopogonids at all four stations was an indication that the entire water body was stressed. The odonates were the single most abundant taxa; their dominance could be attributed to the vegetative nature of the stream, favouring odonate colonisation. Overall, the responses of macroinvertebrates to stress were reflected by the different assemblage structures recorded at the four study stations. Substrate and microhabitat obliteration and poor water quality appeared to be the factors responsible for the observed assemblage structure in the Ogba River.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Monitoramento Ambiental , Invertebrados/crescimento & desenvolvimento , Rios/química , Poluentes Químicos da Água/análise , Animais , Organismos Aquáticos/classificação , Invertebrados/classificação , Nigéria , Qualidade da Água
4.
Acta Chir Belg ; 108(5): 574-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19051469

RESUMO

A retrospective analysis was performed of 46 cases of sarcoma treated in our institution between 1989 and 2007 that occurred in a previously irradiated area. Eight male and 38 female patients had received radiotherapy, mainly for breast cancer and genitourinary tumours. The interval between irradiation and the diagnosis of sarcoma ranged from 1 to 54 years (median 15 y). The most common clinical findings were a mass, pain and skin dislocation. Angiosarcoma and sarcoma non-otherwise-specified were the most common histological types. Surgical resection was performed in 34 patients (74%) and 5-year survival was 45% when a radical resection was obtained. No 5-year survival was noticed after non-radical resection and in the absence of surgery. Stage and location of the sarcoma were other prognostic factors. Overall 5-year survival was 27% for the whole group.


Assuntos
Neoplasias Induzidas por Radiação/mortalidade , Neoplasias Induzidas por Radiação/cirurgia , Sarcoma/mortalidade , Sarcoma/cirurgia , Neoplasias Abdominais/mortalidade , Neoplasias Abdominais/patologia , Neoplasias Abdominais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Extremidades , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias Induzidas por Radiação/patologia , Neoplasias Pélvicas/mortalidade , Neoplasias Pélvicas/patologia , Neoplasias Pélvicas/cirurgia , Estudos Retrospectivos , Sarcoma/patologia , Neoplasias Torácicas/mortalidade , Neoplasias Torácicas/patologia , Neoplasias Torácicas/cirurgia , Adulto Jovem
5.
Cancer Res ; 54(15): 3986-7, 1994 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-8033128

RESUMO

Chromosome investigation in six localized forms of tenosynovial giant cell tumors, also known as modular tenosynovitis, revealed an identical translocation between chromosomes 1 and 2, t(1;2)(p11;q35-36) in three tumors, a variant translocation t(1;5)(p11;q22) in a fourth case, and a t(2;16)(q33;q24) in a fifth case. One case showed a normal karyotype. Although morphologically rather uniform, these benign tumors appear to be cytogenetically heterogeneous, but the chromosome changes seem to cluster in 2 regions, 1p11 and 16q24.


Assuntos
Cromossomos Humanos Par 1 , Cromossomos Humanos Par 2 , Cromossomos Humanos Par 5 , Tumores de Células Gigantes/genética , Membrana Sinovial , Translocação Genética/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade
6.
Am J Surg Pathol ; 21(10): 1166-72, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9331288

RESUMO

Inflammatory myofibroblastic tumor (inflammatory pseudotumor) is a pseudosarcomatous lesion that is recognized with increasing frequency in various anatomic locations. However, this lesion has not been previously reported in bone. We report on two cases of inflammatory myofibroblastic tumor occurring in bone in young adults. Both tumors presented as slightly painful, osteolytic, and well-delineated lesions of the distal femur, with a hyperintense signal on T2-weighted magnetic resonance imaging. The patients had an uneventful recovery after curettage. The follow-up time was 11 months for both patients, and no recurrence was noted. On histologic examination, the lesions were characterized by collagen-rich and generally poorly cellular tissue containing spindled to plump (myo)fibroblast-like cells and a variable admixture of inflammatory cells. Focal calcifications and reactive bone formation were present. Clonal, albeit different, chromosomal changes were found in both cases (47,XY,-9,-12,add(21)(q21),+der(?)t(?;9)(?;q11), +mar,+r and 47, XY, +r/47, idem, add(12)(p13)). The present and other reported cytogenetic findings suggest that inflammatory myofibroblastic tumors could well be neoplastic.


Assuntos
Doenças Ósseas/patologia , Granuloma de Células Plasmáticas/patologia , Adulto , Doenças Ósseas/diagnóstico por imagem , Doenças Ósseas/genética , Aberrações Cromossômicas , Transtornos Cromossômicos , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 21 , Cromossomos Humanos Par 3 , Cromossomos Humanos Par 9 , Marcadores Genéticos , Granuloma de Células Plasmáticas/diagnóstico por imagem , Granuloma de Células Plasmáticas/genética , Humanos , Hibridização In Situ , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/patologia , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios X
7.
Chest ; 112(2): 563-5, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9266905

RESUMO

A case of chronic lithoptysis with unusual features was undiagnosed for 20 years. The presence of multiple broncholiths in different segments of both lungs, not previously described, was confirmed endoscopically. Areas of unusual mucosal punctate calcifications, not appreciated on concurrent high-resolution CT scan, also are described.


Assuntos
Broncopatias , Cálculos , Broncopatias/diagnóstico , Broncopatias/epidemiologia , Broncoscopia , Cálculos/diagnóstico , Cálculos/epidemiologia , Doença Crônica , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva , Tomografia Computadorizada por Raios X
8.
Virchows Arch ; 433(2): 189-91, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9737798

RESUMO

Synovial chondromatosis is a rare lesion, which is still believed by most authors to be reactive rather than neoplastic. We report on a case of synovial chondromatosis with clonal chromosomal changes [43,XX,der (1) t (1;13) (p21-22;q21),-6,-13,-14, add(21) (q21)]. The presence of clonal chromosomal changes in this and in three previously reported cases suggests that synovial chondromatosis is a true neoplastic lesion.


Assuntos
Condromatose Sinovial/genética , Aberrações Cromossômicas , Neoplasias/genética , Adulto , Condromatose Sinovial/patologia , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 13 , Cromossomos Humanos Par 14 , Cromossomos Humanos Par 21 , Cromossomos Humanos Par 6 , Feminino , Humanos , Cariotipagem , Pessoa de Meia-Idade , Translocação Genética
9.
Virchows Arch ; 434(2): 177-80, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10071254

RESUMO

Cytogenetic analysis of a juxta-articular myxoma revealed two distinct cytogenetically abnormal cell populations: inv(2)(p15q36) and +7, t(8;22)(q11-12; q12-13). These clonal chromosomal changes, the first to be reported in this tumour type, suggest that at least some juxta-articular myxomas are neoplastic rather than reactive in nature.


Assuntos
Aberrações Cromossômicas , Artropatias/genética , Mixoma/genética , Feminino , Humanos , Pessoa de Meia-Idade
10.
Arch Surg ; 118(6): 770-1, 1983 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6847377

RESUMO

Occasionally an embolectomy cannot be performed because of failure of the catheter to pass beyond the embolus. We employ a technique that overcomes this problem when it is due to a holdup of the catheter in a branch orifice or atheromatous recess.


Assuntos
Embolização Terapêutica/métodos , Cateterismo/métodos , Humanos
11.
Cancer Genet Cytogenet ; 82(2): 103-5, 1995 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-7664238

RESUMO

A case of therapy-related AML with t(8;16)(p11;p13) 14 months following the end of anthracycline-containing chemotherapy for a nonmetastatic osteosarcoma of the left tibia is presented. The patient was successfully treated with intensive remission-induction chemotherapy. Subsequently, he underwent an uncomplicated allogeneic bone marrow transplantation from his HLA-identical brother and is at present alive and disease-free 10 months after diagnosis of the secondary AML.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Ósseas/tratamento farmacológico , Leucemia Mieloide/genética , Osteossarcoma/tratamento farmacológico , Tíbia , Translocação Genética , Doença Aguda , Adulto , Cisplatino/administração & dosagem , Doxorrubicina/administração & dosagem , Humanos , Cariotipagem , Leucemia Mieloide/induzido quimicamente , Masculino
12.
Cancer Genet Cytogenet ; 77(2): 114-7, 1994 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-7954320

RESUMO

We report the cytogenetic findings of two cases of fibrous dysplasia, one occurring in the tibia, the other in the sphenoid. Both cases exhibited only one chromosome change: a t(6;11)(q15;p15) in the first case, a derivative chromosome 2 in the second. The previous cytogenetic report on fibrous dysplasia revealed only numerical changes. The significance of these inconsistent chromosomal findings in fibrous dysplasia is unclear.


Assuntos
Aberrações Cromossômicas , Displasia Fibrosa Óssea/genética , Adulto , Criança , Cromossomos Humanos Par 11 , Cromossomos Humanos Par 2 , Cromossomos Humanos Par 6 , Feminino , Displasia Fibrosa Óssea/patologia , Humanos , Cariotipagem
13.
Cancer Genet Cytogenet ; 122(1): 30-2, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11104029

RESUMO

The nosologic status of fibrous dysplasia (FD), a well-known and relatively common bone lesion, is controversial. Information collected by the CHromosomes And MorPhology (CHAMP) study group on published and unpublished cases of fibrous dysplasia shows the presence of clonal chromosome changes in at least a proportion of these lesions. The chromosome aberrations found in FD lesions have been quite variable and have included both structural and numerical changes. Two of the three cases investigated at the study group had trisomy 2 as the sole acquired anomaly. Combined with previously published data, +2 and rearrangements involving chromosome band 12p13 have each been detected in 3 of 8 cases with abnormal karyotype of 11 in which chromosomal analysis has been performed, suggesting that FD is a neoplastic lesion rather than a "dysplastic" process, as has been generally believed and as implied by its very name.


Assuntos
Aberrações Cromossômicas , Displasia Fibrosa Óssea/genética , Adolescente , Adulto , Criança , Feminino , Displasia Fibrosa Óssea/patologia , Humanos , Cariotipagem , Masculino
14.
Chem Phys Lipids ; 59(3): 233-44, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1804567

RESUMO

Melittin is shown to affect the structure of the charged phospholipid dipalmitoylphosphatidylglycerol (DPPG). In the gel phase, the presence of melittin leads to (i) an increased lipid interchain vibrational coupling, (ii) a shift of the rectangular to hexagonal lipid packing transition toward low temperatures, (iii) a very small conformational disordering effect, (iv) a decrease of the polarity or hydrogen bonding capability of the lipid ester group surrounding, (v) an important decrease of the water content in the complexes where the remaining water has a more disordered structure than bulk water, and (vi) an interlamellar repeat distance of 79 A. All these observations are rationalized by the following model: adjacent bilayers of DPPG are bridged by tetramers of melittin through electrostatic interactions inducing surface charge neutralization and partial dehydration of the complexes. Melittin also affects the thermotropic behavior of DPPG. When a small amount of the toxin is present, its affinity for charged lipids is such that a phase separation occurs, the domains being stable enough to have their own gel to liquid-crystalline phase transition. In the fluid state, a deeper penetration into the lipid matrix is proposed based on the downshift of the phase transition and the low vibrational interchain coupling. This study brings out general features of cationic species/anionic lipid complexes. The charge neutralization leads to stronger interchain coupling, and electrostatic bridging of adjacent bilayers seems to be common. The hydrophobicity of the peptide is a key factor in the modulation of the gel to liquid-crystalline phase transition and in its insertion in the fluid lipid matrix.


Assuntos
Bicamadas Lipídicas/química , Meliteno/química , Fluidez de Membrana , Fosfatidilgliceróis/química , Ânions , Cátions , Análise de Fourier , Modelos Químicos , Espectrofotometria Infravermelho , Análise Espectral Raman , Difração de Raios X
15.
J Bone Joint Surg Am ; 75(10): 1476-84, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8408136

RESUMO

Between 1972 and 1992, twenty-one patients had a primary operation for the treatment of a sacrococcygeal chordoma; seventeen had had a diagnostic biopsy elsewhere. The average age at the time of the operation was fifty-five years (range, six to seventy-eight years); fourteen patients were male and seven were female. In all patients, a posterior approach was used, even for resections at the cephalic levels of the sacrum. In addition, sixteen of the twenty-one patients were treated with adjuvant radiation therapy. Four patients died; three died of metastatic chordoma. Of the remaining seventeen patients, fifteen were apparently free of disease and had not had a local recurrence at the time of the latest follow-up examination. The average duration of follow-up for these fifteen patients was four and one-half years. Of the nine patients who were followed for at least five years, seven were disease-free at the latest follow-up evaluation. Of the seven patients in whom both second sacral roots were the most caudad nerve-roots spared, four had normal bladder control and five had normal bowel control. Of the four patients in whom the most caudad nerve-roots spared were the first sacral or more cephalic roots, all had impaired bladder control, one had impaired bowel control, and three had a colostomy.


Assuntos
Cordoma/cirurgia , Sacro , Neoplasias da Coluna Vertebral/cirurgia , Adulto , Idoso , Criança , Cordoma/diagnóstico por imagem , Cordoma/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Estudos Retrospectivos , Sacro/diagnóstico por imagem , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/mortalidade , Procedimentos Cirúrgicos Operatórios/métodos , Taxa de Sobrevida , Tomografia Computadorizada por Raios X , Resultado do Tratamento
16.
Reprod Toxicol ; 5(5): 397-403, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1806148

RESUMO

We report the results of the first prospective, multicenter study of acute carbon monoxide (CO) poisoning in pregnancy. We collected and followed cases of CO poisoning occurring during pregnancy between December 1985 and March 1989. The sources of CO were malfunctioning furnaces (n = 16), hot water heaters (n = 7), car fumes (n = 6), and methylene chloride inhalation (n = 3). Pregnancy outcome was adversely affected in 3 of 5 pregnancies with severe toxicity; two stillbirths, and one cerebral palsy with tomographic findings consistent with ischemic damage. All adverse outcome occurred in cases treated with high flow oxygen, whereas the 2 cases of severe toxicity with normal outcomes followed hyperbaric oxygen therapy. All 31 babies exposed in utero to mild or moderate CO poisoning exhibited normal physical and neurobehavioral development. Severe maternal CO toxicity was associated with significantly more adverse fetal cases when compared to mild maternal toxicity (P less than 0.001). It is concluded that while severe CO poisoning poses serious short- and long-term fetal risk, mild accidental exposure is likely to result in normal fetal outcome. Because fetal accumulation of CO is higher and its elimination slower than in the maternal circulation, hyperbaric oxygen may decrease fetal hypoxia and improve outcome.


Assuntos
Anormalidades Induzidas por Medicamentos/epidemiologia , Intoxicação por Monóxido de Carbono/complicações , Complicações na Gravidez/induzido quimicamente , Resultado da Gravidez/epidemiologia , Adolescente , Adulto , Peso ao Nascer/efeitos dos fármacos , Intoxicação por Monóxido de Carbono/terapia , Carboxihemoglobina/metabolismo , Feminino , Idade Gestacional , Humanos , Oxigenoterapia Hiperbárica , Gravidez , Estudos Prospectivos , Fatores de Risco
17.
Spine (Phila Pa 1976) ; 20(11): 1304-6, 1995 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-7660242

RESUMO

STUDY DESIGN: This is a case report. OBJECTIVES: To the authors' knowledge, simultaneous septic arthritis of a lumbar facet joint and another joint has not been described as yet. Therefore, a patient is presented in whom both a lumbar facet joint (L4-L5 on the right) and a sternoclavicular joint were involved. SUMMARY OF BACKGROUND DATA: Septic arthritis of a lumbar facet joint is a rare condition, and only a few cases have been reported in the literature. METHODS: The etiology, clinical presentation, technical examinations, and treatment are reviewed. RESULTS: Antibiotic treatment was sufficient to heal these lesions. CONCLUSION: Antibiotic treatment was sufficient to heal these lesions.


Assuntos
Artrite Infecciosa , Vértebras Lombares , Articulação Esternoclavicular , Antibacterianos/uso terapêutico , Artrite Infecciosa/diagnóstico por imagem , Artrite Infecciosa/tratamento farmacológico , Artrite Infecciosa/etiologia , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Pessoa de Meia-Idade , Radiografia , Articulação Esternoclavicular/diagnóstico por imagem
18.
Angiology ; 29(9): 705-12, 1978 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-707848

RESUMO

A case of occlusive arterial disease of obscure nature and etiology is reported. The most puzzling aspect of this case was an apparent lack of correlation between the acute, progressive clinical course of the disease, especially in its final stages and the absence of any corresponding acute changes on microscopic examination of the affected vessels. Furthermore the combination of clinical features and pathologic findings--particularly the thrombotic involvement of the heart and the thoracic aorta by a process starting in the small and medium size vessels of the lower extremities--is not consistent with any of the recognized syndromes leading to a thrombotic occlusion of the arterial system. We conclude that the case represents an obscure syndrome of progressive occlusive thrombarteriopathy, perhaps related to a cumulative effect of heavy smoking, alcoholism, and drug addiction. It is possible that increased coagulability of the blood contributed to the thrombotic process but was not recognized by means of the hematologic studies performed.


Assuntos
Arteriopatias Oclusivas/diagnóstico , Adulto , Aorta Abdominal/diagnóstico por imagem , Artérias/patologia , Coagulação Sanguínea , Artéria Femoral/diagnóstico por imagem , Humanos , Masculino , Radiografia , Tíbia/diagnóstico por imagem
19.
Proc Inst Mech Eng H ; 216(1): 13-21, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11905557

RESUMO

The currently used intralesional or marginal surgical treatment of a bone tumour in the extremities shows some shortcomings in providing a restoration of the mechanical strength of the bone and the containment of the used filling materials. The use of a medical image based, preformed and custom-made titanium membrane screwed onto the periosteal side of the bone is introduced. This study looks in detail into the design process and the biomechanical evaluation of such a membrane. The buckling strength of the membrane, the strength at the perforation holes and the strength of the screw-bone fixation are tested experimentally. The two latter experiments are performed with different screw types. From the performed tests it appears that a titanium membrane without a wave pattern, of 0.3 mm thickness, fixed to the bone with seven trabecular bone screws (4 mm diameter and 28 mm length) is capable of carrying the anticipated mechanical loads on the reconstructed tibia. The medical image based design methodology and the first clinical application of such a preformed and custom-made titanium membrane are reported and discussed. The feasibility of preformed titanium membranes for bone reconstruction in tumour surgery is demonstrated.


Assuntos
Materiais Biocompatíveis , Neoplasias Ósseas/cirurgia , Substitutos Ósseos , Diagnóstico por Imagem , Fêmur/diagnóstico por imagem , Membranas Artificiais , Titânio , Fenômenos Biomecânicos , Humanos , Teste de Materiais , Tomografia Computadorizada por Raios X
20.
Acta Orthop Belg ; 56(2): 489-95, 1990.
Artigo em Francês | MEDLINE | ID: mdl-2239196

RESUMO

An original technique of direct isthmic reconstruction described by E. Morscher was used in 25 patients with painful spondylolysis after failure of conservative treatment. After a follow-up of 25 months, the functional and radiological results were evaluated and compared with other techniques. Nineteen patients had an excellent or good functional result, in 2 patients the result was fair, and 4 patients had no beneficial effect on pain. The best results were seen in patients younger than 20 years, with an olisthy of less than 10 mm, without associated joint, disc or ligament pathology. In these cases, good results were achieved in 90%, and there was radiological consolidation in 100%.


Assuntos
Fixadores Internos , Espondilólise/cirurgia , Adolescente , Adulto , Criança , Desenho de Equipamento , Feminino , Seguimentos , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Masculino , Radiografia , Espondilólise/diagnóstico por imagem
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