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1.
Rev Med Liege ; 76(5-6): 535-540, 2021 May.
Artigo em Francês | MEDLINE | ID: mdl-34080393

RESUMO

During the past 50 years, the mortality due to childhood cancers decreased dramatically thanks to improvements in supportive care and the use of multimodal approaches. In this context, the long-term follow up after childhood cancer has become a main concern for pediatric oncologists. The SALTO programme was developed in 2012 at the CHR Citadelle in Liège in order to organize a multidisciplinary long-term follow-up for the patients previously treated in our department for a childhood cancer. The aim of the present study was to review, for the most frequent childhood cancers, the long-term sequellae and the second cancers developed by the patients participating to the SALTO programme in order to define the follow-up needed. Our data confirm the importance of a multidisciplinary long-term follow-up, based on the treatments received and following international guidelines.


Au cours des cinquante dernières années, la mortalité liée aux cancers pédiatriques a fortement diminué grâce à une amélioration des soins de support et à l'utilisation d'approches multimodales. Dans ce contexte, le devenir à long terme des patients guéris d'un cancer pédiatrique est devenu une des préoccupations majeures pour les oncologues pédiatres. Dans cette optique, la consultation SALTO («Suivi À Long Terme en Oncologie¼) a été mise en place en 2012 au CHR de la Citadelle pour assurer le suivi multidisciplinaire des adultes ayant été traités dans notre secteur d'hémato-oncologie pédiatrique. L'objectif de cette étude a été de revoir, pour les cancers pédiatriques les plus fréquents, les séquelles et les tumeurs secondaires présentées par les patients suivis en consultation SALTO afin de préciser les modalités du suivi au long cours après cancer pédiatrique. Nos résultats confirment l'importance d'un suivi multidisciplinaire à long terme adapté aux traitements reçus, sur base de recommandations internationales.


Assuntos
Segunda Neoplasia Primária , Neoplasias , Criança , Seguimentos , Humanos , Neoplasias/terapia , Encaminhamento e Consulta , Sobreviventes
4.
Rev Med Interne ; 40(5): 330-333, 2019 May.
Artigo em Francês | MEDLINE | ID: mdl-30391043

RESUMO

INTRODUCTION: Polymyalgia rheumatica (PMR) can be associated with distal swelling indicating an associated RS3PE syndrome. We report a case of PMR associated with oedema of the lower limbs, which resolved rapidly under glucocorticoid therapy. CASE REPORT: A 85-year-old woman presented with a 4 month history of PMR responding to the 2012 EULAR/ACR classification criteria. Examination of the lower limbs revealed pitting oedema bilaterally up to the knees, with mild erythema and warmth. Hypoalbuminemia (30g/L) was present. There was no cardiac, renal or hepatic cause to explain leg swelling. FDG-PET/CT demonstrated increased metabolism in the periarticular area of shoulders and hips. There was no sign of aortitis or neoplasia. Under treatment with prednisone 10mg/day leg swelling disappeared concomitantly to a weight loss of 8kg within 8days. CONCLUSION: This case, the first to report leg swelling of inflammatory origin in the context of PMR, could indicate an increased vascular permeability caused by inflammation in the elderly.


Assuntos
Edema/diagnóstico , Edema/tratamento farmacológico , Perna (Membro)/patologia , Polimialgia Reumática/diagnóstico , Polimialgia Reumática/tratamento farmacológico , Idoso de 80 Anos ou mais , Edema/etiologia , Feminino , Glucocorticoides/uso terapêutico , Humanos , Inflamação/complicações , Inflamação/diagnóstico , Inflamação/tratamento farmacológico , Polimialgia Reumática/complicações , Síndrome , Sinovite/complicações , Sinovite/diagnóstico , Sinovite/tratamento farmacológico
5.
Eye (Lond) ; 26(4): 583-92, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22193879

RESUMO

PURPOSE: To report clinical observations and surgical management in a large series of patients with orbitofacial neurofibromatosis type 1 (OFNF). PATIENTS AND METHODS: Patients were identified and medical records reviewed for demographic data, ophthalmologic examinations, surgical interventions, and procedure outcome to create a retrospective, non-comparative case series of patients with OFNF seen at one medical centre over a 23-year period. RESULTS: Sixty patients with OFNF (31 females and 29 males; mean age, 14 years) were followed for an average of 5.7 years. Presenting signs and symptoms included eyelid swelling in all patients, ptosis in 56 (93.3%), proptosis in 34 (56.6%), dystopia or strabismus in 30 (50%), and decreased visual acuity in 50 (83.3%). Surgical intervention included ptosis repair in 54 (90%; mean 1.6 surgical procedures), facial and orbital tumour debulking in 54 (90%; mean 2.3 surgeries), and canthoplasty in 28 (46.6%) patients. Eleven patients required enucleation or exenteration of a blind eye. CONCLUSION: Patients with OFNF often require multiple procedures to preserve vision, prevent additional disfigurement, and achieve cosmetic rehabilitation. Patients need regular ophthalmological monitoring given the potential for progressive visual and cosmetic consequences.


Assuntos
Neoplasias Faciais/cirurgia , Neurofibromatose 1/cirurgia , Neoplasias Orbitárias/cirurgia , Adolescente , Adulto , Criança , Pré-Escolar , Neoplasias Faciais/patologia , Feminino , Seguimentos , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neurofibromatose 1/patologia , Neoplasias Orbitárias/patologia , Estudos Retrospectivos , Arábia Saudita , Tomografia Computadorizada por Raios X , Acuidade Visual , Adulto Jovem
6.
Nucleic Acids Res ; 38(7): e94, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20071741

RESUMO

Array-based comparative genomic hybridization (aCGH) is a powerful tool to detect genomic imbalances in the human genome. The analysis of aCGH data sets has revealed the existence of a widespread technical artifact termed as 'waves', characterized by an undulating data profile along the chromosome. Here, we describe the development of a novel noise-reduction algorithm, waves aCGH correction algorithm (WACA), based on GC content and fragment size correction. WACA efficiently removes the wave artifact, thereby greatly improving the accuracy of aCGH data analysis. We describe the application of WACA to both real and simulated aCGH data sets, and demonstrate that our algorithm, by systematically correcting for all known sources of bias, is a significant improvement on existing aCGH noise reduction algorithms. WACA and associated files are freely available as Supplementary Data.


Assuntos
Algoritmos , Artefatos , Hibridização Genômica Comparativa/métodos , Composição de Bases , Aberrações Cromossômicas , Simulação por Computador , DNA/química , Humanos , Neoplasias/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos
7.
Neuroradiology ; 43(2): 178-82, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11326568

RESUMO

We report two patients with abnormal development of the lesser wing of the sphenoid bone, globe, optic nerve and cerebral hemisphere without stigmata of neurofibromatosis type 1. The lesser wing of the sphenoid bone was abnormally formed and was not ossified ipsilateral to the dysmorphic eye and underdeveloped cerebral hemisphere. Maldevelopment of the sphenoid wing may interfere with the normal closure of the optic vesicle and normal growth of encephalic structures, possibly by disturbing developmental tissue interactions. These patients may exhibit a type of restricted primary sphenoid dysplasia, while the sphenoid dysplasia of neurofibromatosis type 1 may be secondary to orbital or ocular neurofibromas and other factors associated with that disease.


Assuntos
Microcefalia/diagnóstico por imagem , Microftalmia/diagnóstico por imagem , Osso Esfenoide/anormalidades , Tomografia Computadorizada por Raios X , Criança , Humanos , Masculino , Microcefalia/complicações , Microftalmia/complicações , Neurofibromatose 1/diagnóstico
8.
J Soc Biol ; 194(3-4): 189-93, 2000.
Artigo em Francês | MEDLINE | ID: mdl-11324321

RESUMO

Cyclooxygenase (COX) plays a pivotal role in the biosynthesis of prostanoids. The identification of an inducible isoform, COX-2, besides the constitutive one, COX-1, suggested that the latter was dedicated to cytoprotection, whereas the former was responsible for inflammation and neoplasia. This oversimplification was amended due to the synthesis of new selective inhibitors of COX-2 and to the deletion of the COX-2 gene, which demonstrated the involvement of the inducible isoform in physiological as well as in pathological functions. Moreover, several reports describe effects of nonsteroidal anti-inflammatory drugs which do not result from the inhibition of COX activity.


Assuntos
Regulação Enzimológica da Expressão Gênica , Isoenzimas/genética , Isoenzimas/metabolismo , Prostaglandina-Endoperóxido Sintases/genética , Prostaglandina-Endoperóxido Sintases/metabolismo , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase/farmacologia , Inibidores de Ciclo-Oxigenase/uso terapêutico , Humanos , Inflamação/tratamento farmacológico , Proteínas de Membrana , Neoplasias/tratamento farmacológico , Transdução de Sinais
9.
Eye (Lond) ; 14 ( Pt 1): 82-7, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10755107

RESUMO

PURPOSE: To better describe the clinical and neuroimaging spectrum of abnormalities in clinical anophthalmos. METHODS: We performed a retrospective review of all 17 patients admitted to the King Khaled Eye Specialist Hospital with clinical anophthalmos over a 15 year period who had a complete ophthalmological examination documented and received computed tomographic (CT) imaging of the orbits and brain. RESULTS: Patients with clinical anophthalmos had a high incidence of developmental abnormalities involving both eyes (15/17 patients, 88%), the brain (12/17 patients, 71%) and the body (7/12, 58%). The incidence of central nervous system anomalies reached 100% in patients with bilateral small optic nerves on CT scan. CONCLUSIONS: Patients with clinical anophthalmos share a similar constellation of neurological, somatic and neuroradiological abnormalities as patients with microphthalmos, septo-optic dysplasia and clinical optic nerve hypoplasia. This fact may provide insight into developmental abnormalities of the afferent visual system and brain.


Assuntos
Anormalidades Múltiplas/diagnóstico por imagem , Anoftalmia/diagnóstico por imagem , Encéfalo/anormalidades , Adulto , Criança , Pré-Escolar , Anormalidades do Olho/diagnóstico por imagem , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Microftalmia/diagnóstico por imagem , Nervo Óptico/anormalidades , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
10.
Int Ophthalmol ; 23(1): 11-5, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-11008893

RESUMO

OBJECTIVE: To report changes in retinal arterial and venous blood flow pattern in two patients with tumors involving the entire optic nerve. METHODS: Retrospective review of one patient with clinical and neuroimaging characteristics typical of bilateral optic nerve gliomas and one patient with a probable meningioma of the left optic nerve sheath. RESULTS: The optic nerve glioma patient had reduced peak systolic velocity of central retinal arteries bilaterally, while the patient with an optic nerve sheath meningioma had relatively low central retinal artery flow velocity and intermittent blood flow in the central retinal vein on the affected side. CONCLUSIONS: Reduced retinal arterial flow velocities in the setting of optic nerve gliomas may correlate with the presence of optic nerve disease. Phasic blood flow in the central retinal vein with optic nerve sheath meningioma may be the reason that some patients with this tumor develop retinal choroidal venous anastomoses.


Assuntos
Meningioma/diagnóstico por imagem , Glioma do Nervo Óptico/diagnóstico por imagem , Neoplasias do Nervo Óptico/diagnóstico por imagem , Órbita/diagnóstico por imagem , Artéria Retiniana/diagnóstico por imagem , Veia Retiniana/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Idoso , Velocidade do Fluxo Sanguíneo , Criança , Diagnóstico Diferencial , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Meningioma/irrigação sanguínea , Glioma do Nervo Óptico/irrigação sanguínea , Neoplasias do Nervo Óptico/irrigação sanguínea , Prognóstico , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
11.
Neuroradiology ; 40(10): 662-3, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9833897

RESUMO

Cerebral calcification in children is frequently associated with systemic metabolic disease. We present a case of "marble brain syndrome", which showed this abnormality.


Assuntos
Acidose Tubular Renal , Encefalopatias/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Osteopetrose/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Anidrases Carbônicas/deficiência , Criança , Feminino , Humanos , Síndrome , Tomografia Computadorizada por Raios X
12.
Eye (Lond) ; 12 ( Pt 2): 179-83, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9683934

RESUMO

PURPOSE: The study was designed to evaluate the value of enhanced computed tomography (CT) as a non-invasive test in the detection of optic nerve invasion in retinoblastoma. METHODS: Nineteen eyes in 17 consecutive retinoblastoma patients underwent CT studies performed with high spatial resolution (512 x 512) and 1.5 mm sections, both with enhancement and without enhancement. If the central retinal vessels (CRV) were subjectively visualised with intravenous enhancement, the optic nerve was considered to be free of retinoblastoma. Nineteen enucleated globes were processed for histopathology, and the optic disc and nerve examined with light microscopy for the presence or absence of tumour and the level of involvement. RESULTS: The correlation between the visualisation of CRV and the presence or absence of optic nerve involvement histopathologically was found to be highly significant (p = 0.0006, Fisher exact test). CONCLUSION: In high spatial resolution CT with enhancement and 1.5 mm or thinner sections, non-visualisation of the CRV appears to be a reliable indicator of optic nerve invasion with retinoblastoma.


Assuntos
Nervo Óptico/diagnóstico por imagem , Neoplasias da Retina/diagnóstico por imagem , Retinoblastoma/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Criança , Humanos , Invasividade Neoplásica , Nervo Óptico/patologia , Neoplasias da Retina/patologia , Vasos Retinianos/diagnóstico por imagem , Retinoblastoma/patologia
13.
Eur J Biochem ; 244(2): 587-95, 1997 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-9119028

RESUMO

Reactive oxygen species modulate major cellular functions by mechanisms which are still poorly understood. Recently, H2O2 has been reported to stimulate the activity of the mitogen-activated protein kinases (MAPKs) ERK and JNK, and the expression of the proto-oncogenes c-fos and c-jun. As their expression is enhanced by H2O2 in astrocytes, we studied whether these MAPKs were stimulated by H2O2 in primary cultured astrocytes. The result was positive, a maximum of stimulation being reached with 200 microM H2O2 (0.3 pmol H2O2/cell) for both ERK and JNK. ERK was previously reported to stimulate cytosolic phospholipase A2 phosphorylation and activity. H2O2 stimulated the release of arachidonic acid in astrocytes, as already reported in other cell types. We found also that cPLA2 phosphorylation was increased by H2O2. Moreover, the stimulation by H2O2 of ERK and JNK was decreased by phospholipase A2 activity inhibitors. When astrocytes were incubated first with eicosatetraynoic acid, a structural analogue competing in arachidonic acid metabolism, the stimulation of JNK by H2O was also inhibited, suggesting the involvement of arachidonic acid metabolites. Cyclooxygenase or cytochrome P450 monooxygenase inhibitors failed in decreasing the MAPK stimulation by H2O2, whereas lipoxygenase inhibitors completely abolished that of JNK. Mitogenicity has been reported to be stimulated by H2O2 in other cell types. Although ERK was strongly and durably stimulated by 200 microM H2O2 in astrocytes, at the same extent as by mitogenic growth factors, basal thymidine incorporation rate was decreased by more than 80% after 12-15 h. Moreover, the stimulation of thymidine incorporation induced by basic fibroblast growth factor was transiently abolished by H2O2. Furthermore, H2O2 likely induced the expression of CL100/PAC1/MKP-1, a dual specificity phosphatase which has been implicated in ERK and JNK inactivation in the nucleus. Finally, the prior treatment of astrocytes with MK886, a 5-lipoxygenase-activating protein inhibitor, prevented JNK from stimulation, but did not prevent thymidine incorporation from inhibition, both induced by H2O2. These results strongly suggest an involvement of arachidonic acid and/or its metabolites in the stimulation of both ERK and JNK following the oxidative stress evoked by H2O2, which induced a cell cycle arrest probably independent of the stimulation of JNK.


Assuntos
Ácido Araquidônico/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas de Ciclo Celular , Peróxido de Hidrogênio/farmacologia , Quinases de Proteína Quinase Ativadas por Mitógeno , Proteínas Quinases Ativadas por Mitógeno , Fosfoproteínas Fosfatases , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Células Cultivadas , Citosol/enzimologia , Fosfatase 1 de Especificidade Dupla , Ativação Enzimática/efeitos dos fármacos , Proteínas Imediatamente Precoces/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno , Lipoxigenase/metabolismo , MAP Quinase Quinase 1 , Fosfolipases A/metabolismo , Fosfolipases A2 , Proteína Fosfatase 1 , Proteínas Tirosina Fosfatases/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Timidina/metabolismo
14.
Ann Thorac Surg ; 63(3): 751-5, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9066396

RESUMO

BACKGROUND: Minimally invasive coronary artery bypass grafting aims to achieve less patient discomfort and a more rapid return to active life. Most approaches have used maintenance of the beating heart and control of the target coronary vessel by different hemostatic devices. The purpose of this study was to assess the effects of commonly used coronary artery snares and of the occlusion of the coronary vessel necessary for minimally invasive coronary artery operations on coronary endothelial function. METHODS: Coronary artery bypass grafting with an internal mammary artery to left anterior descending artery anastomosis was performed in a porcine model with a 30-minute period of ischemia and a subsequent 30-minute period of reperfusion, using snares on either side of the anastomotic site to achieve hemostasis of the operative field. Endothelium-dependent relaxation to serotonin was studied in conventional organ chamber experiments with rings taken from the left anterior descending artery at the proximal snare site, the anastomotic site in the segment that underwent the ischemia-reperfusion cycle, the distal snare site, and at a control segment. Responses to potassium chloride and bradykinin were also compared. RESULTS: There were no significant differences in endothelium-dependent relaxation values among the four sites studied. CONCLUSIONS: These results confirm that snaring of the coronary artery for achieving hemostasis at the anastomotic site when performing coronary artery bypass grafting on the beating heart does not cause endothelial dysfunction.


Assuntos
Vasos Coronários/cirurgia , Endotélio Vascular/fisiologia , Hemostasia Cirúrgica/métodos , Anastomose de Artéria Torácica Interna-Coronária/métodos , Animais , Vasos Coronários/fisiologia , Feminino , Hemostasia Cirúrgica/efeitos adversos , Hemostasia Cirúrgica/instrumentação , Anastomose de Artéria Torácica Interna-Coronária/efeitos adversos , Cuidados Intraoperatórios , Masculino , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Suínos
15.
J Pediatr Ophthalmol Strabismus ; 34(6): 372-5, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9430064

RESUMO

PURPOSE: To report two infants with tuberous sclerosis who initially were considered to have retinoblastoma. PATIENTS AND METHODS: An 8-day-old infant was referred with small tumors in the posterior poles of both eyes. A left microphthalmos with ciliochoroidal coloboma was present. Computed tomographic (CT) scanning of the brain showed scattered high-density subependymal foci in the lateral ventricle thought to be consistent with calcification resulting from intrauterine viral infection. Argon laser photocoagulation was applied to lesions in the right eye. Because one tumor was situated on the retina straddling the coloboma in the left eye, external beam radiotherapy was administered. A 5-month-old girl presented with a large mass in a left microphthalmic eye. Calcification was present on B-scan ultrasonography and CT scanning. Vitreous seeding was noted to originate from the tumor. The contralateral eye manifested four small gray translucent retinal tumors in the posterior pole. CT scan and magnetic resonance imaging (MRI) revealed multiple periventricular subependymal lesions, including one at the foramen of Monro. RESULTS: Repeated examinations in the younger child under anesthesia revealed small new retinal lesions that appeared to enlarge gradually. She developed intractable seizures and her electroencephalogram revealed a modified hypsarrhythmia recording. A careful review of available CT scans and MRI displays suggested the diagnosis of tuberous sclerosis. The child's most recent examination under anesthesia revealed multiple newly developed hamartomas. In the older child, prompt diagnosis was made on the basis of the intracranial radiologic findings. CONCLUSION: Retinal hamartoma presentation may vary in infancy. Small, initially fleck-like gliotic lesions appear to enlarge gradually and eventually may form gray, translucent tumors. Large astrocytic hamartomas of the retina associated with tuberous sclerosis may resemble retinoblastoma, particularly if the mass is large, calcified, and associated with vitreous seeding. Although ophthalmic presentation was reminiscent of retinoblastoma in both patients, radiologic evidence of subependymal hamartomas pathognomic for tuberous sclerosis helped establish the correct diagnosis. We stress the importance of intracranial radiologic findings in this regard.


Assuntos
Doenças Retinianas/diagnóstico , Esclerose Tuberosa/diagnóstico , Diagnóstico Diferencial , Ecoencefalografia , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Fotocoagulação a Laser , Imageamento por Ressonância Magnética , Masculino , Doenças Retinianas/radioterapia , Doenças Retinianas/cirurgia , Neoplasias da Retina/diagnóstico , Retinoblastoma/diagnóstico , Tomografia Computadorizada por Raios X , Esclerose Tuberosa/radioterapia , Esclerose Tuberosa/cirurgia
16.
Anal Chem ; 69(11): 2030-4, 1997 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21639242

RESUMO

A new, completely automated gas chromatography technique has been developed to separate the different gaseous compounds produced during underground coal gasification for their (13)C/(12)C and D/H isotope ratio measurements. The technique was designed for separation and collection of H(2), CO, CO(2), H(2)O, H(2)S, CH(4), and heavier hydrocarbons. These gaseous compounds are perfectly separated by the gas-phase chromatograph and quantitatively sent to seven combustion and collection lines. H(2), CO, CH(4), and heavier hydrocarbons are quantitatively oxidized to CO(2) and/or H(2)O. The isotopic analyses are performed by the sealed-tube method. The zinc method is used for reduction of both water and H(2)S to hydrogen for D/H analysis. Including all preparation steps, the reproducibility of isotope abundance values, for a quantity higher than or equal to 0.1 mL of individual components in a mixture (5 mL of gases being initially injected in the gas chromatograph), is ±0.1‰ for δ(13)C(PDB) and ±6‰ for δD(SMOW).

17.
Ann Thorac Surg ; 62(4): 1158-63, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8823106

RESUMO

BACKGROUND: Improvements in myocardial protection may include the continuous delivery of normothermic blood cardioplegia. Technical aids are required for optimal visualization of the operative field during the performance of coronary anastomoses if cardioplegia is to be given continuously or during minimally invasive operations. However, the effects of the different hemostatic devices on coronary endothelial function are unknown. METHODS: We compared the effects on endothelial function of two commonly used hemostatic techniques, coronary clamping and gas jet insufflation, with those of a technique using extravascular balloon occlusion to mimic systolic luminal closure by the surrounding myocardium. The three techniques were applied for 15 minutes on porcine epicardial coronary arteries from explanted hearts. For coronary clamping, standard bulldog clamps were used. Gas jet insufflation was applied by blowing oxygen (12 L/min) tangentially at a 45-degree angle 1 cm away from a 3-mm arteriotomy. Extravascular balloon occlusion was achieved with a needle-tipped silicone loop, the midportion of which, once positioned beneath the coronary artery, was inflated to push a myocardial "cushion" against the back of the vessel until its occlusion. Control rings were taken from the same coronary artery. The endothelial function of control and instrumented arterial rings was then studied in organ chambers filled with modified Krebs-Ringer bicarbonate solution. RESULTS: Contractions to potassium chloride and prostaglandin F2 alpha and endothelium-independent relaxation to sin-1, a nitric oxide donor, were unaffected in all groups. Endothelium-dependent relaxation to serotonin was impaired after clamping and preserved after gas jet insufflation and extravascular balloon occlusion. Maximal endothelium-dependent relaxation to serotonin was as follows: for coronary clamping, 63% +/- 6% versus 87% +/- 3% in controls; for gas jet insufflation, 67% +/- 12% versus 88% +/- 7%; and for extraluminal balloon occlusion, 79% +/- 6% versus 85% +/- 5%. CONCLUSIONS: Whereas commonly used hemostatic devices may impair endothelial function, extravascular balloon occlusion appears to achieve effective hemostasis while preserving endothelial integrity.


Assuntos
Vasos Coronários/fisiologia , Endotélio Vascular/fisiologia , Parada Cardíaca Induzida , Hemostasia Cirúrgica/instrumentação , Revascularização Miocárdica , Instrumentos Cirúrgicos , Animais , Cateterismo/instrumentação , Constrição , Vasos Coronários/patologia , Dinoprosta/farmacologia , Endotélio Vascular/patologia , Hemostasia Cirúrgica/efeitos adversos , Técnicas In Vitro , Procedimentos Cirúrgicos Minimamente Invasivos , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Cloreto de Potássio/farmacologia , Serotonina/farmacologia , Instrumentos Cirúrgicos/efeitos adversos , Suínos , Vasoconstrição/efeitos dos fármacos , Vasodilatadores/farmacologia
18.
J Biol Chem ; 271(40): 24776-80, 1996 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-8798748

RESUMO

The dephosphorylating enzyme alkaline phosphatase, by removing phosphate groups from the external platelet membrane proteins, modulates platelet activation (Hatmi, M., Haye, B., Gavaret, J. M., Vargaftig, B. B., and Jacquemin, C. (1991) Br. J. Pharmacol. 104, 554-558). This observation, together with findings reported by others (Ehrlich, Y. H., Davis, T. B., Bock, E., Kornecki, E., and Lenox, R. H. (1986) Nature 320, 67-70; Dusenbery, K. E., Mendiola, J. R., and Skubitz, K. M. (1988) Biochem. Biophys. Res. Commun. 153, 7-13), indicate the existence of ectoprotein kinase activity on the blood platelet surface. In this study, we demonstrate that washed human platelets phosphorylate the synthetic heptapeptide kemptide in a cAMP-dependent mode. The intensity of the phosphorylation was concentration-dependent for kemptide. In addition, incubation of platelets with [gamma-32P]ATP resulted in a rapid incorporation of [32P] phosphate into proteins at the outer membrane surface that was sensitive to alkaline phosphatase treatment. When cAMP was added to the medium, major phosphorylation of an 88-kDa ectoprotein occurred. Its isoelectric point determined by isoelectric focusing SDS-polyacrylamide gel electrophoresis was around pH 6.2. Phosphorylations of this 88-kDa polypeptide and of the exogenous kemptide substrate were both prevented by the specific protein kinase A inhibitor peptide. When platelets were preincubated with [32P]inorganic phosphate to label intracellular proteins, the protein phosphorylation pattern was different from that obtained with [gamma-32P]ATP, indicating that the latter occurred at the outer surface of the cells. Prostacyclin, which induces the increase of intracellular cAMP levels and, consequently, its liberation into the extracellular medium, increased phosphorylation of both kemptide and platelet 88-kDa polypeptide. The major protein of 88-kDa, which was phosphorylated in the presence of cAMP and external [gamma-32P]ATP, was identified by immunoprecipitation to GPIV (CD36), one of thrombospondin and collagen binding sites on platelets. The phosphorylation of CD36 also occurred in platelet-rich plasma, suggesting a physiological role for this ectoenzyme. In the present study, we clearly demonstrate the presence of an ectoprotein kinase A activity at the surface of intact human platelets, and we revealed its principal endogenous substrate as being CD36.


Assuntos
Plaquetas/enzimologia , Antígenos CD36/metabolismo , AMP Cíclico/metabolismo , Proteínas Quinases/metabolismo , Membrana Celular/metabolismo , Colágeno/metabolismo , Humanos , Glicoproteínas de Membrana/metabolismo , Oligopeptídeos/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Trombospondinas
19.
J Biol Chem ; 270(8): 3693-7, 1995 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-7876108

RESUMO

In the thyroid, thyrotropin (TSH) stimulates both growth and function, and stimulates the production of cAMP which reproduces most of the effects of TSH. Here, we report evidence that TSH stimulates the mitogen-activated protein (MAP) kinase cascade through a cAMP-independent pathway, in human thyroid. TSH stimulated MAP kinase activity (4-9-fold the basal level) measured in the cytosolic fractions of primary cultured thyroid follicles. Maximal activity was reached after 20 min and remained sustained for 1-3 h, TSH being as potent as EGF; EC50 was 1.5 nM TSH. Only a single isoform of MAP kinase (p42) was detected in the follicles. p42 was phosphorylated on tyrosine residues and showed a reduced electrophoretic mobility in follicles stimulated by TSH. All these effects on MAP kinase were decreased by preincubation of the follicles with human anti-TSH receptor antibodies. The stimulation of MAP kinase by TSH was neither blocked by pertussis toxin nor reproduced by forskolin, cholera toxin, or 8-bromo-cAMP. In conclusion, in human thyroid cells, in contrast with previous observations on dog thyroid cells, TSH stimulates strongly MAP kinase through a pertussis toxin-insensitive and cAMP-independent pathway.


Assuntos
Proteínas Quinases/metabolismo , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia , Sequência de Aminoácidos , Animais , Células Cultivadas , AMP Cíclico/biossíntese , AMP Cíclico/farmacologia , Cães , Ativação Enzimática , Fator de Crescimento Epidérmico/farmacologia , Humanos , Dados de Sequência Molecular , Glândula Tireoide/citologia , Glândula Tireoide/enzimologia
20.
Mol Cell Endocrinol ; 99(2): 229-35, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8206331

RESUMO

In this study, we examined whether the protein kinase C (PKC) pathway could interfere with the regulation of Gs protein in porcine thyroid cells. The two days culture of cells with 12-O-tetradecanoylphorbol 13-acetate (TPA) (0.1 microM) alone neither affected adenylyl cyclase activity, nor the level of Gs alpha protein in membranes when compared with control cells. The co-addition of TPA with thyrotropin (TSH) (1 mU/ml) or forskolin (fk) (10 microM) in the culture medium, abolished the stimulatory effects of either agonists on the activation of adenylyl cyclase by fk or [AlF4]- and on the increase of Gs alpha protein. By contrast, TPA had effects neither on the Gi-dependent inhibition of adenylyl cyclase nor on Gi alpha proteins levels. The level of Gs alpha mRNA measured by Northern blot analysis was increased (200%) in TSH- or fk-treated cells and this increase was counteracted by TPA. The effects of TPA observed after 6-9 h of contact with cells were mimicked by mezerezin, a non-phorbol protein kinase C activator and blocked by bisindolylmaleimide a specific protein kinase C inhibitor (GF 109203X). These results suggest that the activation of the PKC pathway prevents the cAMP-dependent up-regulation of Gs alpha protein and Gs alpha mRNA expression.


Assuntos
AMP Cíclico/fisiologia , Diterpenos , Proteínas de Ligação ao GTP/genética , Regulação da Expressão Gênica/efeitos dos fármacos , RNA Mensageiro/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Glândula Tireoide/metabolismo , Adenilil Ciclases/metabolismo , Animais , Northern Blotting , Células Cultivadas , Colforsina/farmacologia , Ativação Enzimática/efeitos dos fármacos , Proteínas de Ligação ao GTP/fisiologia , Cinética , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Suínos , Terpenos/farmacologia , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia
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