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1.
Mod Pathol ; 32(3): 330-337, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30315274

RESUMO

Dedifferentiated metastatic melanoma can pose a significant diagnostic challenge, especially if the history of primary melanoma is not known or is remote. BRAF and NRAS mutations are common melanoma driver mutations that are usually sequenced to evaluate for treatment targets. We evaluated whether BRAF and NRAS mutational testing could contribute to the diagnosis of dedifferentiated metastatic melanoma when immunostains are negative. Seven patients with melanoma who had an additional diagnosis of poorly differentiated sarcoma with negative melanocytic immunostains were tested for BRAF and NRAS mutations. Three patients showed identical BRAF mutations in the melanoma and the poorly differentiated sarcoma and hence were re-classified as metastatic dedifferentiated melanoma. In these three patients, there was an average delay of 7 months before appropriate testing, workup and treatment for metastatic melanoma was initiated. Two of these patients currently have stable metastatic disease and show sustained therapeutic response to melanoma-specific treatment including BRAF inhibitors. BRAF mutational analysis should therefore be considered in cases of poorly differentiated sarcoma, especially if there is a known history of melanoma or with unusual localization of disease. The administration of melanoma-specific treatments in such dedifferentiated cases can show therapeutic response, highlighting the importance of rendering accurate diagnoses on such cases.


Assuntos
Erros de Diagnóstico , Melanoma/diagnóstico , Metástase Neoplásica/diagnóstico , Proteínas Proto-Oncogênicas B-raf/genética , Sarcoma , Neoplasias Cutâneas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Melanoma/genética , Melanoma/terapia , Pessoa de Meia-Idade , Mutação , Metástase Neoplásica/genética , Metástase Neoplásica/terapia , Sarcoma/diagnóstico , Sarcoma/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/terapia
2.
Z Rheumatol ; 75(2): 151-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26783154

RESUMO

BACKGROUND: Immune-mediated necrotizing myopathy (IMNM) is a newly identified subgroup of idiopathic inflammatory myopathies. It is defined as a rare and severe disease, with symmetrical and proximal muscle weakness and a characteristic histology. An autoimmune aspect of IMNM is suggested by its association with autoantibodies directed against signal recognition particle (SRP) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in the majority of patients. Statin use is strongly associated with anti-HMGCR-positive IMNM. The pathophysiological mechanisms of this disease are still poorly understood, and as a result, no therapeutic strategy has been validated to date. OBJECTIVE: The aim of this article is to provide an overview of the current knowledge about epidemiology, clinical features, and pathophysiology of IMNM, as well as treatment strategies. RESULTS AND CONCLUSION: IMNM is a subject of widespread interest, with quick and meaningful advances being made. In recent years, huge progress has been made in terms of diagnosis and patient management. However, the understanding of pathophysiological mechanisms and treatment strategies still requires further investigation.


Assuntos
Doenças Autoimunes/diagnóstico , Doenças Autoimunes/tratamento farmacológico , Miosite/diagnóstico , Miosite/tratamento farmacológico , Doenças Autoimunes/epidemiologia , Medicina Baseada em Evidências , Alemanha/epidemiologia , Humanos , Imunossupressores/uso terapêutico , Miosite/epidemiologia , Prevalência , Doenças Raras/diagnóstico , Doenças Raras/epidemiologia , Doenças Raras/terapia , Resultado do Tratamento
3.
Am J Dermatopathol ; 35(4): 496-502, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23694825

RESUMO

We herein describe 2 cases of adult multivisceral transplant patients who developed graft-versus-host disease manifesting predominantly as lichenoid skin papules and plaques. The diagnosis was supported by histopathology but ultimately corroborated by the utilization of the fluorescence in situ hybridization (FISH) technique using X and Y chromosome probes on unstained biopsy slides. In both cases, FISH revealed a high percentage of donor-derived cells as part of the inflammatory infiltrate in the skin biopsy. This report adds to the previous publications showing the utility of FISH in corroborating the diagnosis of graft-versus-host disease in transplant patients with unmatched sex donor.


Assuntos
Cromossomos Humanos X , Cromossomos Humanos Y , Testes Genéticos/métodos , Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/genética , Hibridização in Situ Fluorescente , Transplante de Órgãos/efeitos adversos , Adulto , Idoso , Biópsia , Sondas de DNA , Evolução Fatal , Feminino , Marcadores Genéticos , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/patologia , Humanos , Imunossupressores/uso terapêutico , Masculino , Valor Preditivo dos Testes , Pele/patologia , Resultado do Tratamento
4.
Rev Neurol (Paris) ; 169(8-9): 663-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24011981

RESUMO

INTRODUCTION: Exercise intolerance (EI) is a frequent motive for seeking neuromuscular consultation and may be a sign of metabolic disease or, rarely, muscular dystrophy. The diagnosis is not established in many patients with a typical clinical presentation. Nevertheless, some of them complain of sleep disorders and more especially of restless legs syndrome (RLS). OBJECTIVE: The objective of our study was to estimate the frequency of RLS in patients presenting with EI. METHODS: Our retrospective observational study included all patients seen in the center from 2005 to 2011, who were subsequently investigated for EI in the neuromuscular department of the Caen University hospital. Data were collected on clinical RLS and muscular investigations (creatine kinase [CK], EMG, maximal exercise tests magnetic resonance imaging [MRI] and muscle biopsy obtained along with muscle exploration). RESULTS: Of the 318 patient records analyzed, 84 showed patients accurately complaining of EI. RLS was diagnosed in 25 of these patients (29.7%). This percentage was significantly higher (P<0.001) than found in the general population. Improvement was seen in 91.3% of the patients receiving specific treatment. CONCLUSION: RLS can sometimes present with pain, potentially worsening with exercise, inappropriately leading to a hypothesis of EI. Clinicians should thus explore the possible diagnosis of RLS when a muscular disease is not found in patients presenting with such symptoms.


Assuntos
Tolerância ao Exercício/fisiologia , Síndrome das Pernas Inquietas/etiologia , Adolescente , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Observacionais como Assunto , Encaminhamento e Consulta , Síndrome das Pernas Inquietas/epidemiologia , Estudos Retrospectivos , Adulto Jovem
5.
Eur Cell Mater ; 21: 243-58, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21409754

RESUMO

Hip resurfacing arthroplasty (HRA) is a concept of hip replacement that allows treating young active patients with a femoral bone preserving procedure. The proposed advantages of resuming an active lifestyle with increased frequency and duration of sports activities have been shown to be realistic. The 30-year cost-effectiveness in young male patients has been shown to be higher in resurfacing compared to conventional total hip replacement (THA). However, prognosticators of an inferior outcome have also been identified. The most important patient related factors are secondary osteoarthritis as the indication for surgery such as post-childhood hip disorders or AVN, female gender, smaller component sizes and older age (>65 years for males and >55 years for females). In addition, surgical technique (approach and cementing technique) and component design are also important determinant factors for the risk of failure. Moreover, concerns have surfaced with respect to high metal ion concentrations and metal ion hypersensitivities. In addition, the presumed ease of revising HRA has not reflected in improved or equal survivorship in comparison to a primary THA. This highlights the importance of identifying patient-, surgery-, and implant-related prognosticators for success or failure of HRA. Rather than vilifying the concept of hip resurfacing, detailed in depth analysis should be used to specify indications and improve implant design and surgical techniques.


Assuntos
Artroplastia de Quadril/tendências , Prótese de Quadril , Humanos , Falha de Prótese , Qualidade de Vida , Resultado do Tratamento
6.
J Chem Phys ; 134(20): 204502, 2011 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-21639451

RESUMO

We report on Brillouin and in situ small angle X-ray scattering (SAXS) analyses of topological heterogeneity in compressed sodium borosilicate glasses. SAXS intensity extrapolated to very low angular regimes, I(q = 0), is related to compressibility. From Brillouin scattering and analyses of the elastic properties of the glass, the Landau-Placzek ratio is determined and taken as a direct reflection of the amplitude of frozen-in density fluctuations. It is demonstrated that with increasing fictive pressure, topological (mid- and long-range) homogeneity of the glass increases significantly. Heating and cooling as well as isothermal scans were performed to follow the evolution of density fluctuations upon pressure recovery. For a sample with a fictive pressure p(f) of 470 MPa, complete recovery to p(f) = 0.1 MPa was observed to occur close to the glass transition temperature. The values of fictive and apparent fictive temperature, respectively, as obtained via the intersection method from plots of I(q = 0) vs. temperature were found in good agreement with previous calorimetric analyses. Isothermal scans suggest that mid- and long-range recovery govern macroscopic density relaxation.

7.
J Cell Biol ; 135(2): 355-70, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8896594

RESUMO

We have recently described a system that recreates in vitro the generation of post-Golgi vesicles from purified Golgi fractions obtained from virus-infected MDCK cells in which the vesicular stomatitis virus-G envelope glycoprotein had been allowed to accumulate in vivo in the TGN. Vesicle formation, monitored by the release of the viral glycoprotein, was shown to require the activation of a GTP-binding ADP ribosylation factor (ARF) protein that promotes the assembly of a vesicle coat in the TGN, and to be regulated by a Golgi-associated protein kinase C (PKC)-like activity. We have now been able to dissect the process of post-Golgi vesicle generation into two sequential stages, one of coat assembly and bud formation, and another of vesicle scission, neither of which requires an ATP supply. The first stage can occur at 20 degrees C, and includes the GTP-dependent activation of the ARF protein, which can be effected by the nonhydrolyzable nucleotide analogue GTP gamma S, whereas the second stage is nucleotide independent and can only occur at a higher temperature of incubation. Cytosolic proteins are required for the vesicle scission step and they cannot be replaced by palmitoyl CoA, which is known to promote, by itself, scission of the coatomer-coated vesicles that mediate intra-Golgi transport. We have found that PKC inhibitors prevented vesicle generation, even when this was sustained by GTP gamma S and ATP levels reduced far below the K(m) of PKC. The inhibitors suppressed vesicle scission without preventing coat assembly, yet to exert their effect, they had to be added before coat assembly took place. This indicates that a target of the putative PKC is activated during the bud assembly stage of vesicle formation, but only acts during the phase of vesicle release. The behavior of the PKC target during vesicle formation resembles that of phospholipase D (PLD), a Golgi-associated enzyme that has been shown to be activated by PKC, even in the absence of the latter's phosphorylating activity. We therefore propose that during coat assembly, PKC activates a PLD that, during the incubation at 37 degrees C, promotes vesicle scission by remodeling the phospholipid bilayer and severing connections between the vesicles and the donor membrane.


Assuntos
Invaginações Revestidas da Membrana Celular/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Complexo de Golgi/metabolismo , Fígado/metabolismo , Organelas/fisiologia , Proteína Quinase C/metabolismo , Fatores de Ribosilação do ADP , Trifosfato de Adenosina/metabolismo , Animais , Proteínas de Transporte/metabolismo , Fracionamento Celular , Linhagem Celular , Invaginações Revestidas da Membrana Celular/ultraestrutura , Citosol/metabolismo , Cães , Guanosina 5'-O-(3-Tiotrifosfato)/farmacologia , Fígado/ultraestrutura , Microscopia Eletrônica , Fosforilação , Sialiltransferases/metabolismo
8.
Biotechnol Lett ; 31(4): 519-23, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19066731

RESUMO

Large scale purification of a class IIa bacteriocin has been developed to recover pure carnocin KZ 213 produced by Carnobacterium piscicola 213. Most previous protocols reported in the literature for the purification of small peptides have used reversed phase chromatography but scale-up is difficult. The first step of this new protocol is hydrophobic interaction chromatography, the second and third steps are cation exchange chromatography. The protocol leads to a complete recovery of carnocin KZ 213 with 95% purity and to a concentration factor of 83. From 10 l culture supernatant, 5.8 mg carnocin KZ 213 have been produced with a specific activity of 8,500 UA g(-1). The protocol is easy to implement for larger volumes.


Assuntos
Proteínas de Bactérias/isolamento & purificação , Bacteriocinas/isolamento & purificação , Bactérias Gram-Positivas/metabolismo , Cromatografia Líquida/métodos
9.
FEMS Microbiol Lett ; 279(1): 1-7, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18070071

RESUMO

Ramularia collo-cygni is now recognized as an important pathogen of barley in Northern Europe and New Zealand. It induces necrotic spotting and premature leaf senescence, leading to loss of green leaf area in crops, and can result in substantial yield losses. The fungus produces a number of anthraquinone toxins called rubellins, which act as host nonspecific toxins with photodynamic activity. These toxins induce lipid peroxidation and are possibly the cause of the chlorosis and necrosis observed in leaves infected with R. collo-cygni. The fact that the fungus can remain latent in barley plants until flowering, coupled with its very slow growth in vitro, makes it difficult to detect in crops. As a result, the epidemiology of this pathogen remains poorly understood. However, the recent development of rapid and reliable PCR methods for specific detection of R. collo-cygni offers the prospect of increased understanding of its epidemiology and improved disease control.


Assuntos
Ascomicetos/fisiologia , Hordeum/microbiologia , Doenças das Plantas/microbiologia , Ascomicetos/isolamento & purificação , Europa (Continente) , Micotoxinas/biossíntese , Micotoxinas/química , Micotoxinas/toxicidade , Nova Zelândia , Folhas de Planta/microbiologia , Reação em Cadeia da Polimerase/métodos
10.
Magn Reson Imaging ; 26(7): 943-53, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18524526

RESUMO

A double inversion-recovery (DIR) sequence with an echo-planar imaging (EPI) readout can be used to image selectively the grey matter of the brain, and this has previously been applied to improve the sensitivity of the statistical analysis of functional magnetic resonance imaging (fMRI) data. If a procedure were to be implemented to remove the distortions that are inherent in the EPI-based fMRI data set, then a similar technique would have to be applied to the DIR-EPI image also to ensure that it matches the geometry of the functional data. A comparison of candidate methodologies for correcting distortions in DIR-EPI images, based on the reversed-gradient method, is presented. A corrected image could be calculated from two DIR-EPI images acquired with k-space traversal in opposite directions, but that method was not able to cope with the large regions of low signal intensity corresponding to the nulled white matter. It was found that the optimal procedure to apply the reversed-gradient method to DIR-EPI images was to acquire two additional EPI images (without the two inversion pulses) with opposite-direction k-space traversal; the distortion-correction information calculated from those EPI images was then applied to the DIR-EPI data.


Assuntos
Mapeamento Encefálico/métodos , Imagem Ecoplanar/métodos , Processamento de Imagem Assistida por Computador/métodos , Humanos , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos
11.
Orthop Traumatol Surg Res ; 104(3): 301-305, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29274861

RESUMO

BACKGROUND: Multiple Ephiphyseal Dysplasia (MED) is a rare autosomal dominant skeletal dysplasia that causes deformation of the epiphysis of the involved joints. The hips are invariably affected and symptoms due to incapacitating early onset degenerative hip disease often begin between the second and fourth decade of life. Literature regarding the clinical and radiographical outcomes after total hip arthroplasty in this young population are very scarce. Hypothesis in patients with multiple epiphyseal dysplasia and early onset degenerative hip disease, hybrid total hip arthroplasty is a safe and reliable procedure. PATIENTS AND METHODS: We followed 10 hybrid total hip arthroplasties in 6 patients with respect to the early and medium term complications. The average age at surgery was 32 years old (17 to 41). All stems were cemented polished straight tapered stems, all cups were porous coated uncemented cups. The mean duration of follow-up was 10.3 (7-14, SD2.8) years. Clinical outcomes were measured using the Charnley modification of the Merle d'Aubigné-Postel grading system and VAS-scores. RESULTS: No early complications and no revisions occurred and patients significantly improved for pain, function and mobility. The Charnley, Merle d'Aubigné and Postel hip scores significantly improved from 9.6 points pre-operatively (range: 8-11 points) to 17 points (range: 16-18 points) and the VAS-score significantly improved after surgery from respectively 7 at rest and 8.5 during activity preoperatively to 1 at rest and 1.5 during activity postoperatively. Radiographic evaluation showed no cases of radiolucency around the cemented femoral components. No migration or subsidence of the components was noted. With regard to the acetabular component, osteolysis was noted in 4 hips, but serial radiographs showed no progression or migration of the component and the patients were completely pain free. CONCLUSION: Hybrid total hip arthroplasty is a viable treatment option in multiple epiphyseal dysplasia patients, with excellent mid-term clinical and radiographical outcomes. LEVEL OF EVIDENCE: Level IV, retrospective study.


Assuntos
Artroplastia de Quadril/métodos , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/fisiopatologia , Osteocondrodisplasias/cirurgia , Acetábulo/diagnóstico por imagem , Adolescente , Adulto , Feminino , Seguimentos , Articulação do Quadril/cirurgia , Prótese de Quadril , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Reoperação , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
12.
Mol Cell Biol ; 19(3): 2338-50, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10022920

RESUMO

Protein tyrosine kinase Pyk2 is activated by a variety of G-protein-coupled receptors and by extracellular signals that elevate intracellular Ca2+ concentration. We have identified a new Pyk2 binding protein designated Pap. Pap is a multidomain protein composed of an N-terminal alpha-helical region with a coiled-coil motif, followed by a pleckstrin homology domain, an Arf-GAP domain, an ankyrin homology region, a proline-rich region, and a C-terminal SH3 domain. We demonstrate that Pap forms a stable complex with Pyk2 and that activation of Pyk2 leads to tyrosine phosphorylation of Pap in living cells. Immunofluorescence experiments demonstrate that Pap is localized in the Golgi apparatus and at the plasma membrane, where it is colocalized with Pyk2. In addition, in vitro recombinant Pap exhibits strong GTPase-activating protein (GAP) activity towards the small GTPases Arf1 and Arf5 and weak activity towards Arf6. Addition of recombinant Pap protein to Golgi preparations prevented Arf-dependent generation of post-Golgi vesicles in vitro. Moreover, overexpression of Pap in cultured cells reduced the constitutive secretion of a marker protein. We propose that Pap functions as a GAP for Arf and that Pyk2 may be involved in regulation of vesicular transport through its interaction with Pap.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Transporte/fisiologia , Proteínas de Ligação ao GTP/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteínas/metabolismo , Domínios de Homologia de src , Fator 1 de Ribosilação do ADP , Fatores de Ribosilação do ADP , Sequência de Aminoácidos , Animais , Células COS , Proteínas de Transporte/genética , Linhagem Celular Transformada , Quinase 2 de Adesão Focal , Proteínas Ativadoras de GTPase , Complexo de Golgi/metabolismo , Células HeLa , Humanos , Líquido Intracelular , Camundongos , Dados de Sequência Molecular , Células PC12 , Fosforilação , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Coelhos , Ratos , Tirosina/metabolismo
13.
Biotechnol Lett ; 29(4): 553-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17216301

RESUMO

Aureobasidium pullulans (de Bary) Arnaud (Ach 1-1) was grown in a glucose fed-batch fermentor to 106 g dry wt l(-1) in 48 h. The cells were dried in a fluidized bed dryer with a final viability of 62%. After 7 months at 4 degrees C, the viability was 28% of the initial value (= 2.3 x 10(10 )c.f.u. g(-1) dry matter). A protection level of 89% was achieved with the biomass preparation at 1 x 10(8 )c.f.u. ml(-1) after 28 and 7 days for apples stored respectively at 5 and 25 degrees C against Penicillium expansum. Our process is suitable to produce large quantities of the strain Ach 1-1 as biological control agent for apple preservation.


Assuntos
Ascomicetos/citologia , Ascomicetos/fisiologia , Reatores Biológicos/microbiologia , Técnicas de Cultura de Células/métodos , Fungicidas Industriais , Penicillium/citologia , Penicillium/fisiologia , Proliferação de Células , Sobrevivência Celular , Técnicas de Cocultura/métodos , Controle Biológico de Vetores/métodos
14.
Folia Neuropathol ; 54(3): 295-302, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27764522

RESUMO

INTRODUCTION: The clinical and histological presentations of the adult form of Pompe disease may be atypical. In such cases, identifying histological signs that point to the diagnosis would be crucial to avoid a delay in care. The aim of our study was to investigate the presence of rimmed vacuoles and acid phosphatase positivity in muscle biopsies of patients with late-onset Pompe disease. MATERIAL AND METHODS: We retrospectively studied muscle biopsies of all cases of the adult form of Pompe disease diagnosed at the University Hospital of Caen. Three of these four cases showed atypical clinical signs, and diagnosis was established tardily based on family history or systematic analysis of acid maltase activity. RESULTS: All biopsies showed some rimmed vacuoles. The acid phosphatase reaction showed positive inclusions and labelled vacuoles in biopsies of all patients. CONCLUSIONS: The presence of rimmed vacuoles and acid phosphatase positivity in muscle biopsy should suggest the diagnosis of the adult form of Pompe disease, this is decisive since effective therapy is available.


Assuntos
Fosfatase Ácida/metabolismo , Doença de Depósito de Glicogênio Tipo II/diagnóstico , Doença de Depósito de Glicogênio Tipo II/patologia , Vacúolos/patologia , Adulto , Idade de Início , Biomarcadores/análise , Biópsia , Feminino , Doença de Depósito de Glicogênio Tipo II/metabolismo , Humanos , Corpos de Inclusão/patologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Estudos Retrospectivos
15.
Biochim Biophys Acta ; 1051(2): 123-30, 1990 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-2310766

RESUMO

The prohormone chromogranin A is the major soluble component of secretory granules in chromaffin cells of adrenal medulla and in many other different endocrine cell types. The proteolytic processing of chromogranin A was studied in cultured bovine chromaffin cells using [35S]methionine to label proteins and a specific antibody to immunoprecipitate the native protein and its breakdown products. In resting cells, it was found that the degradation of chromogranin A is a slow process, since no degradation was observed after a 40 h incubation with radiolabelled methionine. Stimulation of cells with a single pulse or with successive pulses of nicotine did not significantly enhance the degree of proteolytic processing of chromogranin A. As it has recently been shown (Simon, J.P., Bader, M.F. and Aunis, D. Biochem. J. (1989) 260, 915-922) that protein kinase C may be involved in the regulation of chromogranin A synthesis, the possibility that prohormone processing may also be controlled by protein kinase C was examined using the activator of protein kinase C, 12-O-tetradecanoylphorbol 13-acetate (TPA). However, incubation of cells with TPA did not significantly modify chromogranin A processing, indicating that biosynthesis and proteolytic processing of chromogranin A are two distinctly regulated mechanisms. Glucocorticoids are known to exert regulatory control of chromaffin cell metabolism; however, incubation of cells with dexamethasone did not alter slow chromogranin A processing. Stimulation of labelled cells rapidly released newly synthesized chromogranin A into external medium. In addition, released chromogranin A was found to be actively processed into its 60 kDa and 43 kDa breakdown products. This extracellular proteolytic degradation mechanism may be of importance with regard to the function of chromogranin A as a prohormone.


Assuntos
Sistema Cromafim/metabolismo , Cromograninas/metabolismo , Células Enterocromafins/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Anticorpos/análise , Catecolaminas/metabolismo , Fracionamento Celular , Células Cultivadas , Grânulos Cromafim/metabolismo , Cromogranina A , Cromograninas/biossíntese , Cromograninas/imunologia , Meios de Cultura/metabolismo , Eletroforese em Gel de Poliacrilamida , Soros Imunes/análise , Metionina/metabolismo , Testes de Precipitina , Fatores de Tempo
16.
J Am Coll Cardiol ; 27(7): 1662-8, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8636551

RESUMO

OBJECTIVES: This study sought to determine whether the reopening of the infarct-related vessel is related to clinical characteristics or cardiovascular risk factors, or both. BACKGROUND: In acute myocardial infarction, thrombolytic therapy reduces mortality by restoring the patency of the infarct-related vessel. However, despite the use of thrombolytic agents, the infarct-related vessel remains occluded in up to 40% of patients. METHODS: We studied 295 consecutive patients with an acute myocardial infarction who underwent coronary angiography within 15 days (mean [+/- SD] 6.7 +/- 3.2 days) of the onset of symptoms. Infarct-related artery patency was defined by Thrombolysis in Myocardial Infarction trial flow grade > or = 2. Four cardiovascular risk factors--smoking, hypertension, hypercholesterolemia and diabetes mellitus--and eight different variables-age, gender, in-hospital death, history of previous myocardial infarction, location of current myocardial infarction, use of thrombolytic agents, time interval between onset of symptoms, thrombolytic therapy and coronary angiography--were recorded in all patients. RESULTS: Thrombolysis in current smokers and anterior infard location on admission were the three independent factors highly correlated with the patency of the infarct-related vessel (odds ratios 3.2, 3.0 and 1.9, respectively). In smokers, thrombolytic therapy was associated with a higher reopening rate of the infard vessel, from 35% to 77% (p < 0.001). Nonsmokers did not benefit from thrombolytic therapy, regardless of infarct location. CONCLUSIONS: These observational data, if replicated, suggest that in patients with acute myocardial infarction, thrombolytic therapy may be most effective in current smokers, whereas nonsmokers and ex-smokers may require other management strategies, such as emergency percutaneous transluminal coronary angioplasty.


Assuntos
Infarto do Miocárdio/tratamento farmacológico , Ativadores de Plasminogênio/uso terapêutico , Fumar/efeitos adversos , Estreptoquinase/uso terapêutico , Terapia Trombolítica , Ativador de Plasminogênio Tecidual/uso terapêutico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Fatores de Risco , Volume Sistólico , Falha de Tratamento , Grau de Desobstrução Vascular
17.
Mol Endocrinol ; 14(4): 459-71, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10770485

RESUMO

A member of the G protein-coupled receptor superfamily, the LH receptor (LHR), and the two other glycoprotein hormone receptors are distinguished from the other members by the presence of a relatively large N-terminal extracellular domain that is responsible for high-affinity ligand binding. Transmembrane helix (TMH) 7 of LHR is amphipathic, with an extended face containing only hydrophobic side chains and another containing both hydrophobic and polar side chains with potential hydrogen bond donor and acceptor functions. Since several reports have shown the importance of this helix in ligand-mediated signaling, we have used Ala scanning mutagenesis to study eight amino acid residues of rat LHR that are invariant in the three glycoprotein hormone receptors, Leu586, Val587, Asn593, Ser594, Cys595, Asn597, Phe604, and Thr605. The wild type (WT) and mutant cDNAs were transiently transfected into COS-7 cells for characterization by human CG (hCG) binding and cAMP production. No differences were detected in dissociation constants (K(d)S) or basal cAMP production relative to WT LHR, but three categories of LHR mutants were distinguished from WT LHR based upon their expression levels and responsiveness to hCG: 1) comparable or higher expression but reduced ligand responsiveness (N593A and C595A), 2) reduced expression and ligand responsiveness (N597A and T605A), and 3) comparable expression and responsiveness (L586A, V587A, S594A, and F604A). Three other mutants, C595M, F604Y, and T605Y, were comparable to WT LHR in ligand responsiveness. To provide more information on Asn593 and Asn597, a total of 12 replacements were investigated. Of considerable interest and potential significance was the finding that many of the replacements in LHR resulted in either loss of function (N593A, Q, S; N597R) or gain of function (N593R and N597Q), this being the first evidence of a position in LHR that, depending upon the nature of the amino acid residue, can result in constitutive activation and/or diminished responsiveness to ligand. The results of molecular modeling and energy minimization of TMHs 6 and 7, based on a postulated interaction between Asp556 (TMH 6) and Asn593/Asn597 (TMH 7), indicated that, while there is not a correlation between function and predicted energies of WT LHR and the mutants, reorientation of one or both helices is responsible for the functional changes observed. Possible interactions of TMHs 3 and 4 and of 5 and 6 were suggested by molecular modeling. Ten mutants were prepared of two amino acid residues that are invariant in the glycoprotein hormone receptors and have side chain hydrogen bond donor and acceptor function, Glu429 in TMH 3 and Asn513 in TMH 5. Expression levels and hCG-mediated signaling were reduced in most of the LHR mutants, but none of these exhibited constitutive receptor activation. We conclude that Glu429 is not critical for receptor function, while Asn513 appears to be particularly important in receptor folding and/or trafficking. The results reported herein indicate an important role for TMH 7, and particularly Asn593 and Asn597, in the process of receptor activation. Moreover, these two asparagines, although in close proximity to each other in TMH 7, are quite distinct in function as evidenced by certain replacements that can lead to loss of function in one and gain of function in the other.


Assuntos
Estrutura Secundária de Proteína/fisiologia , Receptores do LH/química , Sequência de Aminoácidos , Animais , Asparagina , Células COS , Gonadotropina Coriônica/metabolismo , AMP Cíclico/biossíntese , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Ratos , Receptores do LH/genética , Receptores do LH/metabolismo , Serina , Transdução de Sinais , Relação Estrutura-Atividade , Treonina , Transfecção
18.
Proc Inst Mech Eng H ; 219(3): 163-74, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15934392

RESUMO

Bone cutting in total joint reconstructions requires a high accuracy to obtain a well-functioning and long-lasting prosthesis. Hence robot assistance can be useful to increase the precision of the surgical actions. A drawback of current robot systems is that they autonomously machine the bone, in that way ignoring the surgeon's experience and introducing a safety risk. This paper presents a semi-active milling procedure to overcome that drawback. In this procedure the surgeon controls robot motion by exerting forces on a force-controlled lever that is attached to the robot end effector. Meanwhile the robot constrains tool motion to the planned motion and generates a tool feed determined by the feed force that the surgeon executes. As a case study the presented milling procedure has been implemented on a laboratory set-up for robot-assisted preparation of the acetabulum in total hip arthroplasty. Two machining methods have been considered. In the first method the surgeon determines both milling trajectory and feed by the forces that he/she executes on the force-controlled lever. In the second method the cavity is machined contour by contour, and the surgeon only provides the feed. Machining experiments have shown that the first method results in large surface irregularities and is not useful. The second method, however, results in accurate cavity preparation and has therefore potential to be implemented in future robot systems.


Assuntos
Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Prótese de Quadril , Robótica/instrumentação , Robótica/métodos , Cirurgia Assistida por Computador/métodos , Interface Usuário-Computador , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Sistemas Computacionais , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Modelos Biológicos , Procedimentos Ortopédicos/instrumentação , Procedimentos Ortopédicos/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Cirurgia Assistida por Computador/instrumentação
19.
J Invest Dermatol ; 118(5): 806-11, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11982757

RESUMO

In pemphigus vulgaris the major pathogenic antibody binds desmoglein-3, and mediates mucosal disease. Development of cutaneous disease is associated with acquisition of antibodies to desmoglein-1. In pemphigus foliaceus, and its endemic form, fogo selvagem by contrast, the major pathogenic antibody recognizes desmoglein-1 and mediates cutaneous disease only. In this study, we sought to determine the prevalence of antibodies to desmoglein-3 in patients with pemphigus foliaceus and fogo selvagem. We produced recombinant desmoglein-1 and desmoglein-3, and used them in highly sensitive and specific enzyme-linked immunosorbent assays, as well as immunoprecipitation assays. We detected antibodies to desmoglein-3 in 19 of 276 patients with pemphigus foliaceus and fogo selvagem, who had cutaneous disease only. We showed that these antibodies to desmoglein-3 could be absorbed in a concentration-dependent manner by desmoglein-3 but not by desmoglein-1. Also antibodies to desmoglein-1 could be absorbed in a concentration-dependent manner by desmoglein-1 but not desmoglein-3. This suggests that two separate species of antibody are present rather than one antibody capable of cross-reacting with both desmoglein-1 and desmoglein-3. Finally, it was shown that affinity-purified antibodies to desmoglein-3 from patients with pemphigus foliaceus and fogo selvagem induced a pemphigus vulgaris-like skin disease in mice by passive transfer. These results suggest that a subset of patients with pemphigus foliaceus and fogo selvagem have antibodies to desmoglein-3 that may be involved in the pathogenesis of their cutaneous disease.


Assuntos
Autoanticorpos/sangue , Caderinas/imunologia , Pênfigo/imunologia , Animais , Animais Recém-Nascidos , Autoanticorpos/farmacologia , Desmogleína 1 , Desmogleína 3 , Ensaio de Imunoadsorção Enzimática , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Sensibilidade e Especificidade , Pele/imunologia
20.
Hum Immunol ; 29(2): 143-9, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1979072

RESUMO

Using RFLP, the present study sets off to determine the MHC class II gene polymorphism in Graves' disease, in order to define the HLA-related genetic susceptibility. Considering the preferential link between Graves' disease and the HLA-DR3 antigen, 42 HLA-DR3 Graves' disease patients were studied and compared with 42 HLA-DR-matched controls. Hybridization with a DQ alpha probe of DNAs digested by Taq I revealed a polymorphism of the DR3 haplotype with an overrepresentation of a 2.1 kb(U) fragment in patients, but this was merely a sign of the linkage disequilibrium between U and B8DR3. Hybridization with the DR beta probe of DNAs digested by Taq I yielded more facts. It revealed the overrepresentation of the Dw24 specificity (Taq I:9.8 kb) in DR3 Graves' disease patients. This study thus enabled us to determine precisely the susceptibility linked to the DR3 haplotype, implicating the DRB3 gene and its Dw24 allele, which appear to be the most reliable markers of the disease, providing a higher relative risk than B8DR3.


Assuntos
Doenças Autoimunes/genética , Genes MHC da Classe II , Doença de Graves/genética , Antígenos HLA-DR/genética , Alelos , Desoxirribonucleases de Sítio Específico do Tipo II , Suscetibilidade a Doenças , Frequência do Gene , Genótipo , Antígenos HLA-DQ/genética , Subtipos Sorológicos de HLA-DR , Humanos , Fenótipo , Polimorfismo de Fragmento de Restrição , Fatores de Risco
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