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2.
J Fr Ophtalmol ; 29(1): 11-8, 2006 Jan.
Artigo em Francês | MEDLINE | ID: mdl-16465118

RESUMO

PURPOSE: To assess in vivo the corneal epithelial damage caused by a topical toxic medication using a 60-MHz ultrasound device. MATERIAL: and methods: A solution of timolol with 0.01% benzalkonium chloride (BAC) was applied twice a day in the test eyes of ten rabbits, and a BAC-free solution of timolol in the control eyes, for 56 days. We used a 60-MHz ultrasound device to evaluate the epithelial damage in BAC-exposed eyes, compared to control eyes. The clinical and ultrasound examinations were performed every week, and the histological analysis at the end of the experiment. RESULTS: The clinical findings were conjunctival redness, corneal staining and instability of the tear film. In vivo VHF ultrasound revealed a thinning of the epithelium of test eyes (from 40.9+/-1,6 microm at D0 to 31.8+/-3.4 microm at D56; p=0.0006 for D0 vs D56), while the epithelium of control eyes remained unchanged. Ultrasound epithelial thickness was correlated with corneal staining (at D34 and D56; p=0.0025 and 0.0377, respectively) and histological epithelial pachymetry (p=0.0176 for control and 0.0505 for tested epithelium). Moreover, we report qualitative VHF ultrasound imaging of early epithelial damage. CONCLUSION: This new device could be very useful in ocular toxicity evaluation as a reproducible and reliable tool for multicentric clinical research.


Assuntos
Compostos de Benzalcônio/toxicidade , Epitélio Corneano/efeitos dos fármacos , Epitélio Corneano/diagnóstico por imagem , Conservantes Farmacêuticos/toxicidade , Timolol/toxicidade , Animais , Combinação de Medicamentos , Masculino , Coelhos , Ultrassonografia
3.
Rev Neurol (Paris) ; 160(4 Pt 1): 478-82, 2004 Apr.
Artigo em Francês | MEDLINE | ID: mdl-15103277

RESUMO

INTRODUCTION: Dissection of cervical arteries is a frequent cause of stroke in young subjects. CASE REPORT: We report the case of a 34-year-old patient who experienced simultaneous dissection of both internal carotid arteries and both vertebral arteries leading to repeated motor deficit of the right half-body associated with persistent otalgia. Search for an etiology led to the diagnosis of Ehlers-Danlos syndrome type IV. CONCLUSION: Search for the cause of cervical artery dissection must consider connective tIssue disease, particularly vascular forms of Ehler-Danlos syndrome. Diagnostic, therapeutic as well as prognostic aspects are discussed.


Assuntos
Dissecção Aórtica/etiologia , Artérias Carótidas , Síndrome de Ehlers-Danlos/complicações , Artéria Vertebral , Adulto , Síndrome de Ehlers-Danlos/diagnóstico , Feminino , Humanos
4.
J Fr Ophtalmol ; 27(3): 271-7, 2004 Mar.
Artigo em Francês | MEDLINE | ID: mdl-15039630

RESUMO

We report three cases of endophthalmitis following cataract extraction. Enterococcus faecalis was the causative organism in all of them. Initial visual acuity was only light perception in all cases, final visual acuity was negative light perception in two cases, and light perception in one case. After initial improvement, inflammation was exacerbated in one patient and evisceration realized. The capsular bag was examined using scanning electron microscopy and it was shown that enterococci were adherent to the capsular bag, four months after the onset of the infection. Enterococcus faecalis can be the causative agent both of an acute and a chronic form of post operative endophthalmitis. Experimental studies on rabbit eyes could explain the poor prognosis of these endophtalmitis and focused on bacterial toxins. The contamination appears to be post operative, because Enterococcus faecalis is not a commensal agent of the conjunctiva. So we have to inform our patients about some hygienic habits, to prevent from this devastating complication of cataract surgery.


Assuntos
Endoftalmite/microbiologia , Enterococcus faecalis , Infecções por Bactérias Gram-Positivas , Complicações Pós-Operatórias/microbiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade
5.
Int J Pharm ; 228(1-2): 69-77, 2001 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-11576769

RESUMO

The effect of low-frequency sonophoresis on fentanyl and caffeine permeation through human and hairless rat skin was studied in vitro. Experiments were performed using 20 kHz ultrasound applied at either continuous or discontinuous mode and with an average intensity of 2.5 W/cm(2). The results showed that low-frequency ultrasound enhanced the transdermal transport of both fentanyl and caffeine across human and hairless rat skin. This was explained by both increasing flux during sonication and shortening the lag time. Discontinuous mode was found to be more effective in increasing transdermal penetration of fentanyl while transdermal transport of caffeine was enhanced by both continuous and pulsed mode. Histological and electron microscopy studies showed that human and hairless rat skin was unaffected by ultrasound exposure. Further studies will be necessary to determine the relative contribution of ultrasound parameters in low-frequency ultrasound-induced percutaneous enhancement of drug transport.


Assuntos
Analgésicos Opioides/farmacocinética , Cafeína/farmacocinética , Estimulantes do Sistema Nervoso Central/farmacocinética , Fentanila/farmacocinética , Absorção Cutânea/efeitos da radiação , Administração Cutânea , Analgésicos Opioides/administração & dosagem , Animais , Área Sob a Curva , Cafeína/administração & dosagem , Estimulantes do Sistema Nervoso Central/administração & dosagem , Difusão , Fentanila/administração & dosagem , Humanos , Técnicas In Vitro , Masculino , Membranas/efeitos dos fármacos , Membranas/ultraestrutura , Ratos , Pele/ultraestrutura , Ultrassom
6.
Anat Rec ; 264(1): 114-9, 2001 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-11505377

RESUMO

The use of low-frequency ultrasound has been proposed to enhance the transdermal transport of various drugs, a technique referred to as sonophoresis. The aim of the present study was to determine the safety of low-frequency sonophoresis on human and rat skin by evaluating their structural modifications after ultrasound exposure. Human skin samples and hairless rats were exposed to 20 kHz ultrasound in vitro and in vivo, respectively. Ultrasound was used with average intensities ranging from 0.25 to 7 W/cm(2) in pulsed or continuous mode. Hairless rats were also exposed to a heat source mimicking the temperature versus time profile during sonication. Skin samples were observed under optical and electron microscopy to detect any structural changes. Human skin samples exposed to intensities lower than 2.5 W/cm(2) showed no modification. For hairless rats, slight and transient erythema was observed after 2.5 W/cm(2) exposure, whereas deep lesions (dermal and muscle necrosis) were observed 24 hr later. These lesions were also observed when a plastic film was placed between the coupling medium and the animals' skin during sonication. In contrast, no histologic lesion could be seen when a heat source was applied to animal skin. Low-frequency ultrasound induces delayed and deep lesions in hairless rat skin at 2.5 W/cm(2) which are not only attributable to the increase in temperature at the skin surface during ultrasound exposure. By using the same ultrasound conditions, human skin seems to be less sensitive in vitro.


Assuntos
Temperatura Cutânea/efeitos da radiação , Pele/patologia , Pele/efeitos da radiação , Ultrassom , Animais , Humanos , Técnicas In Vitro , Masculino , Microscopia Eletrônica , Óptica e Fotônica , Ratos , Pele/fisiopatologia
7.
Exp Cell Res ; 262(1): 28-36, 2001 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11120602

RESUMO

We examined the spatial distribution of MMP-2 on the surface of human endothelial cells using immunofluorescence and confocal microscopy. Staining endothelial cells with MMP-2-specific antibodies revealed a punctate labeling at the basolateral side of the cell periphery, which colocalized with patches of caveolin-1, a major constituent of the caveolae. This colocalization was confirmed by immunogold electron microscopy. MT1-MMP, TIMP-2, and the alphavbeta3 integrin exhibited a similar pattern of staining, with pericellular patches that colocalized with either MMP-2 or caveolin-1. The presence of MT1-MMP and TIMP-2 in caveolae patches could be seen only after treatment with concanavalin A, which induced MMP-2 activation but had no noticeable effect on the pattern or intensity of MMP-2 immunostaining. In contrast, MMP-9 and TIMP-1 staining showed a pattern completely different from that of MMP-2 and TIMP-2, with positive spots uniformly distributed throughout the cell body. Our data show that MMP-2, its activator the MT1-MMP, and its proposed receptor, the alphavbeta3 integrin, are all targeted to the same membrane microdomains on the endothelial cell, thereby restricting matrix proteolysis to a limited microenvironment at the cell surface.


Assuntos
Cavéolas/química , Caveolinas/análise , Endotélio Vascular/química , Metaloproteinase 2 da Matriz/análise , Adulto , Caveolina 1 , Células Cultivadas , Endotélio Vascular/citologia , Humanos , Metaloproteinases da Matriz Associadas à Membrana , Metaloendopeptidases/análise , Receptores de Vitronectina/análise
8.
Br J Dermatol ; 143(4): 876-83, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11069477

RESUMO

We report a French pedigree with members having an inherited combination of non-epidermolytic palmoplantar keratoderma (NEPPK) and sensorineural deafness. The penetrance of both features was incomplete. Additional ectodermal defects were absent. The expression of numerous epidermal proteins (keratins, fillagrin, cornified envelope proteins, intercellular junction proteins including connexin 26, and loricrin) defined with immunolabelling was normal in the proband. The combination was shown to be associated with the A7445G point mutation in the mitochondrial genome (mtDNA). This mutation is responsible for a subtype of NEPPK which is so far the only mtDNA mutation-associated keratoderma.


Assuntos
DNA Mitocondrial/genética , Perda Auditiva Neurossensorial/genética , Ceratodermia Palmar e Plantar/genética , Mutação Puntual , Adolescente , Criança , Feminino , Humanos , Ceratodermia Palmar e Plantar/patologia , Masculino , Linhagem
9.
Thromb Res ; 98(5): 423-33, 2000 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10828482

RESUMO

The role of glycoprotein Ia/IIa was studied during platelet contact and aggregation induced by type I and type III collagen. The anti-glycoprotein Ia/IIa (6F1) antibody inhibited type I collagen-induced aggregation but did not inhibit the first contact between platelets and collagen. In contrast, it was without effect either on type III collagen-induced contact or platelet interaction with the subendothelium in a static assay. Platelet aggregation induced by type III collagen was only slightly slowed down by 6F1 but pp72 spleen tyrosine kinase phosphorylation was not modified even at concentrations of 6F1 that completely blocked platelet activation induced by type I collagen. Our results indicate that glycoprotein Ia/IIa is not a primary binding site for type I or type III collagen on the platelet membrane. This receptor is more specifically involved in type I collagen-induced platelet spreading and aggregation.


Assuntos
Plaquetas/química , Colágeno/farmacologia , Integrinas/fisiologia , Ativação Plaquetária/efeitos dos fármacos , Anticorpos Monoclonais/farmacologia , Plaquetas/citologia , Colágeno/metabolismo , Endotélio Vascular/ultraestrutura , Matriz Extracelular/metabolismo , Humanos , Integrinas/imunologia , Cinética , Microscopia Eletrônica de Varredura , Fosforilação , Adesividade Plaquetária , Agregação Plaquetária/efeitos dos fármacos , Receptores de Colágeno , Tirosina/metabolismo
10.
Ann Dermatol Venereol ; 127(4): 381-7, 2000 Apr.
Artigo em Francês | MEDLINE | ID: mdl-10844258

RESUMO

OBJECTIVE: Desquamative gingivitis is a chronic diffuse inflammation of the gingiva. The aim of this study was to determine the causes and the clinical characteristics of desquamative gingivitis. PATIENTS AND METHODS: This was a retrospective descriptive study including 33 consecutive patients (25 women and 8 men) seen at a dermatology clinic for erosive gingivitis. RESULTS: Thirteen patients (39 p. 100) had cicatricial pemphigoid, 12 (36 p. 100) had lichen planus, and 5 (15 p. 100) had pemphigus. Delay to diagnosis was a mean 19 months. The pinch sign was positive in 12 of the 13 cases of cicatricial pemphigoid. Dapsone improved the buccal lesions of cicatricial pemphigoid in all cases. Systemic corticosteroid therapy and acitretine were the most effective treatments for lichen planus and corticosteroid therapy improved pemphigus in all cases. At the time of assessment, only 3 cases of cicatricial pemphigoid, 2 cases of lichen planus and 1 case of pemphigus had reached complete remission without treatment. DISCUSSION: Cicatricial pemphigoid and lichen planus are the most frequent causes of desquamative gingivitis, accounting for three-quarters of the cases. Positive diagnosis may be difficult and may require sophisticated techniques to avoid delay. Despite the effectiveness of symptomatic treatment, desquamative gingivitis may have a long course.


Assuntos
Gengivite/diagnóstico , Gengivite/etiologia , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Síndrome
11.
Eur J Obstet Gynecol Reprod Biol ; 85(2): 185-90, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10584633

RESUMO

The aim of this study was to determine the role of Magnetic Resonance Imaging (MRI) in investigating fetal cerebral lesions induced by long term exposure to cocaine during sheep pregnancy. Cerebral Magnetic Resonance Imaging was performed on two groups of fetuses at 125 days of gestation (normal gestation: 145 days). The control group consisted of eight fetuses of four pregnant ewes. The study group consisted of eight fetuses of four pregnant ewes receiving daily 140 mg/kg injection of cocaine from day 60 until delivery. The following MR sequences were applied: T1-weighted FLASH, and T2-weighted Fast-Spin-Echo. Cerebral images were evaluated semi quantitatively using the following criteria: Heterogenicity, contrast between grey and white matter, contours irregularity, hyposignal, lateral ventricle sizes. The brightness distribution and homogenicity of the images were analysed by means of edge pair distributions using a new computerized method originally designed for ultrasound images analysis developed by Ultrasight inc (USA). (1) Flash T1: Heterogenic areas and irregular contours were more frequent in cocaine exposed fetuses. The contrast between grey and white matter was more important in the cocaine group. Hyposignal was found only in the cocaine group. Enlarged lateral ventricle occurred more frequently in the cocaine group. (2) Spin echo T2: The contrast between grey and white matter was higher and the contours of the brain more irregular in the cocaine group. Heterogenicity and hyposignal were also more frequent in this group but the difference with the control group was not significant. The computerized analysis of the contrast density on the cerebral images showed that 88% of the areas exceeding the reference level concerned the cocaine group, while only 14% of the areas exceeding the reference level concerned the control group. Long term exposure to cocaine induces cerebral tissue modifications, in favor of an advanced maturation and the development of hypoxic lesions. The histology of the brains confirmed in the cocaine group, the existence of hypoxic lesions with gliosis, perivascular edema and hemorrhages, and neuronal death.


Assuntos
Encéfalo/embriologia , Cocaína/efeitos adversos , Imageamento por Ressonância Magnética , Animais , Encéfalo/patologia , Edema Encefálico/induzido quimicamente , Hemorragia Cerebral/induzido quimicamente , Cocaína/administração & dosagem , Feminino , Idade Gestacional , Troca Materno-Fetal , Microscopia Eletrônica , Neurônios/patologia , Gravidez , Ovinos
12.
Eur J Obstet Gynecol Reprod Biol ; 86(1): 15-22, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10471137

RESUMO

OBJECTIVE: To assess the development of brain damage in an ovine fetal chronic cocaine model. To evaluate the effect of isolated hypoxic tests on this model and to correlate hemodynamic findings (brain-sparing effect) following fetal hypoxia and the occurrence of brain damage. STUDY DESIGN: Fifteen ewes were divided into a control group (n=7) and a cocaine treated group (n=8). From day 65 to day 134 the cocaine treated animals received a daily (5 days per week) intramuscular injection (2 mg/kg cocaine) and the control animals a placebo injection (2 ml of isotonic solution). Both groups underwent hypoxic tests (cord compression (3 min) and aortic compression (1 min)) at 90 and 134 days. In addition, anesthesia for magnetic resonance imaging (MRI) examination was carried out at 125 days. Fetal blood samples were collected during both series of hypoxic tests and the cerebral and umbilical flows were monitored by Doppler. Samples from 25 brains (control n = 10; cocaine n= 15) were processed for light and electron microscopic examination. Quantification of brain damage was done on semithin sections from six areas of cortex and germinal matrix on each fetus. RESULTS: Similar forms of brain damage (selective neuronal loss limited to the parasaggital cortex, striatum, hippocampus and Purkinje cells) was present in both groups but lesions were more frequent in the cocaine treated group as shown by quantitative analysis for the proportion of abnormal capillaries (65% vs. 35%), capillary edema (61% vs. 34%) and abnormal neurons showing delayed neuronal degeneration (DND) (66% vs. 36%) in the cocaine and control group respectively. There was no significant difference in immunoreactivity for glial fibrillary acidic protein (GFAP) but it was more marked in the cerebellum of cocaine treated animals. Fetal blood samples showed a moderate sustained hypoxia and Doppler findings demonstrated the presence of a brain sparing effect associated with increased uterine and umbilical vascular resistance in the cocaine treated group. Nevertheless, the amplitude of the heart rate increase and cerebral dilatation was significantly lower in the cocaine treated animals. CONCLUSION: This ovine fetal chronic cocaine model showed the presence of brain damage. Cocaine treatment seems to potentiate the effect of the hypoxic tests. Independent of the cause, the brain damage developed in the presence of brain sparing effect, strongly suggesting that this phenomenon is a sign of a pathological fetal condition and no guarantee that it will prevent tissue damage.


Assuntos
Dano Encefálico Crônico/patologia , Cocaína , Hipóxia Fetal/complicações , Animais , Apoptose , Dano Encefálico Crônico/induzido quimicamente , Dano Encefálico Crônico/etiologia , Núcleo Celular/patologia , Cocaína/administração & dosagem , Citoplasma/patologia , Modelos Animais de Doenças , Feminino , Hipóxia Fetal/patologia , Proteína Glial Fibrilar Ácida/análise , Microscopia Eletrônica , Neurônios/patologia , Gravidez , Ovinos
13.
J Fr Ophtalmol ; 22(1): 61-6, 1999 Feb.
Artigo em Francês | MEDLINE | ID: mdl-10221194

RESUMO

PURPOSE: To localize the collagen type VI, laminin et fibrillin in glaucomatous and non-glaucomatous trabecular meshworks. MATERIAL: Twenty-four trabeculectomy specimens from patients suffering of primary open angle glaucoma (POAG, 15 cases), pigmentary glaucoma (PG, 2 cases), pseudo-exfoliative glaucoma (PEG, 7 cases) and 2 non glaucomatous aged trabeculums of enucleated eyes. METHODS: Post-embedding immunogold indirect labelings on 4% paraformaldehyde-0.1% glutaraldehyde fixed and LRWhite embedded samples. RESULTS: Labeling of type VI collagen was observed on the 64 nm collagen fibers in all samples, less intensively on POAG or PG disorganised microfibril areas, and especially on PEG pseudo-exfoliative material deposits. Laminin labeling was strongly positive on healthy basal membranes and less intense on POAG and PG abnormal basal membranes. Fibrillin labeling was found on POAG or PG disorganized microfibril areas, especially around pigment granules, around 64 nm striated collagen fibers and with a mild intensity on POAG and PG juxtacanalicular microgranular substance areas. No labeling was found on pseudo-exfoliative substance deposits. CONCLUSION: Collagen type VI abundance in pseudo-exfoliative substance deposits could result from a fibrillogenesis abnormality. POAG and PG basal membrane ultrastructural abnormalities and weak laminin content could share the origin. The abundance of fibrillin in disorganized microfibrils could result from the chronic elevated tensile strength due to ocular hypertony.


Assuntos
Colágeno/análise , Glaucoma/patologia , Imuno-Histoquímica , Laminina/análise , Proteínas dos Microfilamentos/análise , Malha Trabecular/patologia , Idoso , Idoso de 80 Anos ou mais , Síndrome de Exfoliação/patologia , Feminino , Fibrilinas , Glaucoma de Ângulo Aberto/patologia , Humanos , Masculino , Valores de Referência
14.
Arch Dermatol ; 134(9): 1075-80, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9762017

RESUMO

OBJECTIVE: To check the potential usefulness of clinical criteria for the diagnosis of bullous pemphigoid when state-of-the-art techniques such as Western immunoblotting, immunoprecipitation, and indirect immunofluorescence on salt-split skin or direct immunoelectron microscopy are not available. DESIGN: Comparison of the clinical criteria between 2 groups (with and without bullous pemphigoid) as defined by immunoelectron microscopy used as standard criterion, in a prospective study. Multivariate logistic regression analysis was carried out by including all items that were statistically significant (at P < .05 level) in univariate analysis. SETTING: Five dermatology departments in teaching hospitals. PATIENTS: The 231 patients studied had subepidermal autoimmune bullous diseases with linear IgG or C3 deposits in the basement membrane zone (157 with bullous pemphigoid, 33 with cicatricial pemphigoid, 30 with epidermolysis bullous acquisita, 5 with lupus erythematosus, and 6 others). A second set of patients was used to calculate predictive values. RESULTS: The multivariate logistic stepwise analysis resulted in a final set of predictors that included only 4 items: absence of atrophic scars, absence of head and neck involvement, absence of mucosal involvement, and age greater than 70 years. No additional variables met the .05 significance level to enter into the model. If 3 of these 4 characteristics were present, a diagnosis of bullous pemphigoid could be made with a sensitivity of 90% and a specificity of 83%; these predictive values were calculated on a sample of 70 new cases. CONCLUSIONS: With and estimated incidence of bullous pemphigoid among subepidermal autoimmune bullous diseases of 80%, the presence of 3 of the 4 significant criteria allows the diagnosis of bullous pemphigoid, with a positive predictive value of 95%. Our set of clinical criteria thus allows the diagnosis of bullous pemphigoid with good validity for both clinical practice and therapeutic trials.


Assuntos
Penfigoide Bolhoso/patologia , Idoso , Feminino , Humanos , Masculino , Análise Multivariada , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade
15.
Arterioscler Thromb Vasc Biol ; 17(10): 2293-305, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9351403

RESUMO

In a previous study, we have demonstrated that the platelet adhesive glycoprotein thrombospondin-1 (TSP-1) interacts specifically with the cytoskeletal protein alpha-actinin in a solid-phase binding assay. Stored in the alpha-granules of platelets, TSP-1 is secreted during cell activation and binds to the plasma membrane promoting the platelet macroaggregate formation. However, the molecular mechanism by which TSP-1 reaches and binds to the platelet surface is to date unelucidated. alpha-Actinin is an actin-binding and actinin-cross-linking protein that is present in most cells and may act as a link between the bundles of F-actin and the plasma membrane. In this study, we have investigated a possible interaction of alpha-actinin with TSP-1 in platelets by examining their respective subcellular location during the platelet activation process. By indirect immunofluorescence. alpha-actinin was found to display a granular staining in resting platelets similar to that of TSP-1. Performing postembedding immunogold labeling for electron microscopy, we detected the presence of alpha-actinin throughout the cytoplasm, but the strongest gold staining was found in organelles identified as alpha-granules on the basis of their ultrastructure and TSP-1 content. With the use of double immunogold labeling on platelets at different stages of activation by thrombin, both alpha-actinin and TSP-1 were seen redistributing from the alpha-granules to the platelet surface via the open canalicular system (OCS). At the same time, the cytoplasmic alpha-actinin concentrated toward the plasma membrane, but no colocalization with the F-actin bundles was evidenced. Finally, preembedding immunogold labeling and immunoprecipitation of 125I-surface-labeled, thrombin-activated platelets further demonstrated that alpha-actinin was expressed on the plasma membrane in the absence of any detectable expression of actin and that it could from molecular complexes with TSP-1 on activated platelets. These results suggest that alpha-actinin found to be present on the platelet surface together with TSP-1 originates in the alpha-granules by fusion of the alpha-granules with the plasma membrane during platelet exocytosis.


Assuntos
Actinina/metabolismo , Plaquetas/metabolismo , Grânulos Citoplasmáticos/química , Exocitose , Trombospondinas/metabolismo , Western Blotting , Citoesqueleto/química , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Microscopia Imunoeletrônica , Testes de Precipitina , Trombina/farmacologia
16.
J Neurosurg ; 87(1): 67-72, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9202267

RESUMO

The so-called Dorello's canal was studied in 32 specimens (16 human cadaver heads) injected with colored latex and fixed in formalin (28 specimens) or studied with microscopic and ultrastructural methods (four specimens). To avoid the differences usually encountered in the description of this area, the authors preferred to consider a larger space that they have named the petroclival venous confluence (PVC). It was located between two dural layers: inner (or cerebral) and outer (or osteoperiosteal). The PVC was quadrangular on transverse section. The posterior petroclinoid fold and the axial plane below the dural foramen of the abducent nerve (sixth cranial nerve) limited the PVC at the top and bottom, respectively. Its anteroinferior limit was the posterosuperior aspect of the upper clivus and outer layer of the dura mater. Its anterior limit was the vertical plane containing the posterior petroclinoid fold, and its posterior limit was the inner layer of the dura. The PVC was limited laterally by the medial aspect of the petrous bone apex and medially by the virtual sagittal plane extending the medial limit of the inferior petrosal sinus upward. The PVC was a venous space bordered by endothelium and continuous with the cavernous sinus, the basal sinus of the clivus, and the inferior petrosal sinus. There were trabeculations between the two dural layers. The petrosphenoidal ligament of Gruber may be regarded as a larger trabeculation, and it divided the PVC into a superior and an inferior compartment. The abducent nerve generally ran through the inferior compartment, where it was fixed to the surrounding dura mater. This nerve was only separated from venous blood by a meningeal sheath of varying thinness lined with endothelium. The clinical implications of these findings are discussed.


Assuntos
Fossa Craniana Posterior/anatomia & histologia , Fossa Craniana Posterior/irrigação sanguínea , Osso Petroso/anatomia & histologia , Osso Petroso/irrigação sanguínea , Nervo Abducente/anatomia & histologia , Cadáver , Fossa Craniana Posterior/inervação , Humanos , Osso Petroso/inervação , Veias/anatomia & histologia
17.
C R Acad Sci III ; 319(4): 333-41, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8762981

RESUMO

We report the results of an immunogold electron microscopical analysis on microfibrils from the arterial subendothelium showing that thrombospondin (TSP) is present on 40 nm-diameter structures joining 8-10 nm-diameter microfibrils containing fibrillin. They differ from type VI collagen which forms 3-5 nm-diameter microfibrils. TSP containing microfibrils (TSP-MF) extracted from human umbilical arteries did not contain fibrillin or type VI collagen. Blood platelet interactions with TSP-MF were not modified by anti-fibrillin or anti-type VI collagen antibodies. In situ, vWF was bound to cross-linked microfibrils, at the level of their 40 nm junction, and a double-labeling with the anti-thrombospondin and anti-vWF antibodies was observed. In vitro, vWF binding to TSP-MF was not inhibited by anti-fibrillin or anti-type VI collagen antibodies. These results suggest a structural and functional heterogeneity of microfibrils and emphasize the role of TSP-MF in the thrombogenicity of the subendothelium.


Assuntos
Endotélio Vascular/imunologia , Glicoproteínas de Membrana/imunologia , Proteínas dos Microfilamentos/metabolismo , Colágeno/imunologia , Proteínas da Matriz Extracelular , Fibrilinas , Humanos , Técnicas In Vitro , Proteínas dos Microfilamentos/imunologia , Microscopia Imunoeletrônica , Agregação Plaquetária , Trombospondinas , Fator de von Willebrand/imunologia
18.
Arterioscler Thromb Vasc Biol ; 16(1): 56-63, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8548427

RESUMO

To evaluate the involvement of the glycoprotein (GP) IIb/IIIa-dependent process in platelet deposition and thrombus growth on capillaries coated with human type III collagen, the effects of incremental doses of Lamifiban, a potent specific synthetic GPIIb/IIIa antagonist, were studied in ex vivo capillary perfusion chambers using guinea pig blood. In this model, nonanticoagulated blood was perfused for 4.5 minutes at three shear rates: 100, 650, and 1600 s-1. Platelet deposition was quantified by computer-assisted morphometry and expressed as platelet adhesion (percentage of capillary surface covered with spread and contact platelets and platelets implicated in thrombus), mean thrombus height, and total thrombus cross-sectional area. In control untreated guinea pigs, platelet adhesion and thrombus height were 63% and 2.5 microns at 100 s-1, 60.5% and 13.8 microns at 650 s-1, and 45% and 28.1 microns at 1600 s-1, respectively. At 100 s-1, Lamifiban had no effect on platelet deposition at any of the three doses administered to the guinea pigs (0.3, 1, and 3 mg/kg). At 0.3 mg/kg and shear rates of 650 and 1600 s-1, Lamifiban had no effect on platelet adhesion or thrombus size, but at 1 and 3 mg/kg and shear rates of 650 and 1600 s-1, it significantly reduced thrombus size. At 1600 s-1, 1 mg/kg Lamifiban significantly increased platelet adhesion from 45% to 62.5%, whereas at 3 mg/kg it induced a significant overall decrease from 45% to 25% and qualitatively increased the ratio of contact to spread platelets. These data suggest that at high shear rates, GPIIb/IIIa participates in platelet spreading and that there is a balance between platelet involvement in adhesion to the thrombogenic surface and the growth of the already formed thrombus. This indicates that important clinical implications of an optimal therapeutic degree of GPIIb/IIIa antagonism could be expected.


Assuntos
Acetatos/farmacologia , Anticoagulantes/farmacologia , Adesividade Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Trombose/prevenção & controle , Tirosina/análogos & derivados , Animais , Ação Capilar , Colágeno , Fibrina/metabolismo , Cobaias , Humanos , Técnicas In Vitro , Masculino , Microscopia Eletrônica de Varredura , Perfusão , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Trombose/patologia , Tirosina/farmacologia
19.
Ann Dermatol Venereol ; 123(3): 188-90, 1996.
Artigo em Francês | MEDLINE | ID: mdl-8761782

RESUMO

INTRODUCTION: Elastosis perforans serpiginosa frequently occurs in trisomy 21. Usually no cause is found. We report a case in which vitamin deficiency may have contributed to the development of skin lesions. CASE REPORT: A 11-year-old girl with trisomy 21 developed papulokeratosic eruptions with a linear serpiginous distribution, predominantly involving the lower limbs. On ultrastructure examination, numerous elastic fibers penetrated the epiderma and the baseline membrane had disappeared. The patient also had a totally patent atrioventricular canal with hypoplasia of the left ventricle and cardiac liver. Serum vitamin A level was low (0.56 mumol/l, normal > 1.55). Acitretine was prescribed at the dose of 0.5 mg/kg/day but had to be stopped 2 months later due to elevated liver enzyme levels despite a clear clinical improvement. DISCUSSION: This association between elastosis perforans serpiginosa and vitamin A deficiency, observed here in a child with trisomy 21, has never been reported by others. Vitamin A deficiency might aggravate the skin lesions. In our case, there was probably a relationship between the vitamin A deficiency and the cardiogenic liver disease. The keratoregulatory effect of vitamin A on elastic tissue is less well known. Treatment with retinoids provided clinical improvement but had to be stopped due to hepatotoxicity. Parenteral vitamin A would be an interesting alternative but the risk of side effects would theoretically be greater than with oral retinoids.


Assuntos
Síndrome de Down/complicações , Tecido Elástico , Dermatoses da Perna/etiologia , Deficiência de Vitamina A/etiologia , Acitretina/efeitos adversos , Acitretina/uso terapêutico , Criança , Feminino , Humanos , Ceratolíticos/efeitos adversos , Ceratolíticos/uso terapêutico , Dermatoses da Perna/patologia
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